Frequency response implemented

Need a form

21 files changed, 773 insertions, 520 deletions

diff --git a/Project/Bus.cpp b/Project/Bus.cpp
index eecc06a..37eac3e 100644
--- a/Project/Bus.cpp
+++ b/Project/Bus.cpp
@@ -239,23 +239,31 @@ wxString Bus::GetTipText() const
     }
 
     tipText += _("\n\nSsc = ") + wxString::FromDouble(std::abs(m_electricalData.scPower), 5) + _(" p.u.");
+    tipText += _("\n\nTHD = ") + wxString::FromDouble(std::abs(m_electricalData.thd), 5) + wxT("\%");
 
     return tipText;
 }
 
-bool Bus::GetPlotData(ElementPlotData& plotData)
+bool Bus::GetPlotData(ElementPlotData& plotData, PlotStudy study)
 {
-    if(!m_electricalData.plotBus) return false;
-    plotData.SetName(m_electricalData.name);
-    plotData.SetCurveType(ElementPlotData::CT_BUS);
-
-    std::vector<double> absVoltage, argVoltage;
-    for(unsigned int i = 0; i < m_electricalData.stabVoltageVector.size(); ++i) {
-        absVoltage.push_back(std::abs(m_electricalData.stabVoltageVector[i]));
-        argVoltage.push_back(wxRadToDeg(std::arg(m_electricalData.stabVoltageVector[i])));
+    if(study == STABILITY) {
+        if(!m_electricalData.plotBus) return false;
+        plotData.SetName(m_electricalData.name);
+        plotData.SetCurveType(ElementPlotData::CT_BUS);
+
+        std::vector<double> absVoltage, argVoltage;
+        for(unsigned int i = 0; i < m_electricalData.stabVoltageVector.size(); ++i) {
+            absVoltage.push_back(std::abs(m_electricalData.stabVoltageVector[i]));
+            argVoltage.push_back(wxRadToDeg(std::arg(m_electricalData.stabVoltageVector[i])));
+        }
+        plotData.AddData(absVoltage, _("Voltage"));
+        plotData.AddData(argVoltage, _("Angle"));
+    } else if(FREQRESPONSE) {
+        //if(!m_electricalData.plotBus) return false;
+        plotData.SetName(m_electricalData.name);
+        plotData.SetCurveType(ElementPlotData::CT_BUS);
+        plotData.AddData(m_electricalData.absImpedanceVector, _("Impedance"));
     }
-    plotData.AddData(absVoltage, _("Voltage"));
-    plotData.AddData(argVoltage, _("Angle"));
     return true;
 }
 
diff --git a/Project/Bus.h b/Project/Bus.h
index 2423be6..e2947ac 100644
--- a/Project/Bus.h
+++ b/Project/Bus.h
@@ -62,6 +62,8 @@ struct BusElectricalData {
     std::vector<int> harmonicOrder;
     std::vector< std::complex<double> > harmonicVoltage;
     double thd = 0.0;
+    
+    std::vector<double> absImpedanceVector;
 };
 
 /**
@@ -92,7 +94,7 @@ class Bus : public PowerElement
     virtual BusElectricalData GetElectricalData() const { return m_electricalData; }
     virtual void SetElectricalData(BusElectricalData electricalData) { m_electricalData = electricalData; }
     virtual bool ShowForm(wxWindow* parent, Element* element);
-    virtual bool GetPlotData(ElementPlotData& plotData);
+    virtual bool GetPlotData(ElementPlotData& plotData, PlotStudy study = STABILITY);
     
     virtual rapidxml::xml_node<>* SaveElement(rapidxml::xml_document<>& doc, rapidxml::xml_node<>* elementListNode);
     virtual bool OpenElement(rapidxml::xml_node<>* elementNode);
diff --git a/Project/FileHanding.cpp b/Project/FileHanding.cpp
index 7120063..f5facbf 100644
--- a/Project/FileHanding.cpp
+++ b/Project/FileHanding.cpp
@@ -232,7 +232,7 @@ void FileHanding::SaveProject(wxFileName path)
         elementID++;
     }
     //}
-    
+
     //{ HarmCurrent
     auto harmCurrentNode = XMLParser::AppendNode(doc, elementsNode, "HarmCurrentList");
     auto harmCurrentList = allElements.GetHarmCurrentList();
@@ -492,19 +492,20 @@ bool FileHanding::OpenProject(wxFileName path)
 
         transfomerNode = transfomerNode->next_sibling("Transfomer");
     }  //}
-    
-    //{ Transformer
+
+    //{ HarmCurrent
     auto harmCurrentListNode = elementsNode->first_node("HarmCurrentList");
-    if(!harmCurrentListNode) return false;
-    auto harmCurrentNode = harmCurrentListNode->first_node("HarmCurrent");
-    while(harmCurrentNode) {
-        HarmCurrent* harmCurrent = new HarmCurrent();
+    if(harmCurrentListNode) {
+        auto harmCurrentNode = harmCurrentListNode->first_node("HarmCurrent");
+        while(harmCurrentNode) {
+            HarmCurrent* harmCurrent = new HarmCurrent();
 
-        if(!harmCurrent->OpenElement(harmCurrentNode, parentList)) return false;
-        elementList.push_back(harmCurrent);
-        harmCurrentList.push_back(harmCurrent);
+            if(!harmCurrent->OpenElement(harmCurrentNode, parentList)) return false;
+            elementList.push_back(harmCurrent);
+            harmCurrentList.push_back(harmCurrent);
 
-        harmCurrentNode = harmCurrentNode->next_sibling("HarmCurrent");
+            harmCurrentNode = harmCurrentNode->next_sibling("HarmCurrent");
+        }
     }  //}
 
     m_workspace->SetElementList(elementList);
diff --git a/Project/Load.cpp b/Project/Load.cpp
index 64c5514..d9f1b2a 100644
--- a/Project/Load.cpp
+++ b/Project/Load.cpp
@@ -248,7 +248,7 @@ wxString Load::GetTipText() const
     return tipText;
 }
 
-bool Load::GetPlotData(ElementPlotData& plotData)
+bool Load::GetPlotData(ElementPlotData& plotData, PlotStudy study)
 {
     if(!m_electricalData.plotLoad) return false;
     plotData.SetName(m_electricalData.name);
diff --git a/Project/Load.h b/Project/Load.h
index 342f377..4fa01ad 100644
--- a/Project/Load.h
+++ b/Project/Load.h
@@ -87,7 +87,7 @@ class Load : public Shunt
     LoadElectricalData GetElectricalData() { return m_electricalData; }
     LoadElectricalData GetPUElectricalData(double systemPowerBase);
     void SetElectricalData(LoadElectricalData electricalData) { m_electricalData = electricalData; }
-    virtual bool GetPlotData(ElementPlotData& plotData);
+    virtual bool GetPlotData(ElementPlotData& plotData, PlotStudy study = STABILITY);
 
     virtual rapidxml::xml_node<>* SaveElement(rapidxml::xml_document<>& doc, rapidxml::xml_node<>* elementListNode);
     virtual bool OpenElement(rapidxml::xml_node<>* elementNode, std::vector<Element*> parentList);
diff --git a/Project/MainFrame.cpp b/Project/MainFrame.cpp
index 3af0545..5e81c89 100644
--- a/Project/MainFrame.cpp
+++ b/Project/MainFrame.cpp
@@ -22,12 +22,12 @@
 #include "DataReport.h"
 #include "FileHanding.h"
 #include "GeneralPropertiesForm.h"
+#include "HarmCurrent.h"
 #include "ImportForm.h"
 #include "IndMotor.h"
 #include "Inductor.h"
 #include "Line.h"
 #include "Load.h"
-#include "HarmCurrent.h"
 #include "MainFrame.h"
 #include "PropertiesData.h"
 #include "SimulationsSettingsForm.h"
@@ -153,8 +153,9 @@ void MainFrame::CreateAddElementsMenu()
                                                   _("Adds a shunt capacitor at the circuit"));
     wxMenuItem* inductorElement = new wxMenuItem(m_addElementsMenu, ID_ADDMENU_INDUCTOR, _("&Inductor\tShift-I"),
                                                  _("Adds a shunt inductor at the circuit"));
-    wxMenuItem* harmCurrentElement = new wxMenuItem(m_addElementsMenu, ID_ADDMENU_HARMCURRENT, _("&Harmonic current\tShift-H"),
-                                                 _("Adds a harmonic current source at the circuit"));
+    wxMenuItem* harmCurrentElement =
+        new wxMenuItem(m_addElementsMenu, ID_ADDMENU_HARMCURRENT, _("&Harmonic current\tShift-H"),
+                       _("Adds a harmonic current source at the circuit"));
 
     m_addElementsMenu->Append(busElement);
     m_addElementsMenu->Append(lineElement);
@@ -446,8 +447,8 @@ void MainFrame::OnAddElementsClick(wxCommandEvent& event)
                     newElement = true;
                 } break;
                 case ID_ADDMENU_HARMCURRENT: {
-                    HarmCurrent* newHarmCurrent =
-                        new HarmCurrent(wxString::Format(_("Harmonic Current %d"), workspace->GetElementNumber(ID_INDUCTOR)));
+                    HarmCurrent* newHarmCurrent = new HarmCurrent(
+                        wxString::Format(_("Harmonic Current %d"), workspace->GetElementNumber(ID_INDUCTOR)));
                     workspace->IncrementElementNumber(ID_HARMCURRENT);
                     elementList.push_back(newHarmCurrent);
                     statusBarText = _("Insert Harmonic Current Source: Click on a buses, ESC to cancel.");
@@ -556,6 +557,8 @@ void MainFrame::OnSimulationSettingsClick(wxRibbonButtonBarEvent& event)
 }
 void MainFrame::OnFreqResponseClick(wxRibbonButtonBarEvent& event)
 {
+    Workspace* workspace = static_cast<Workspace*>(m_auiNotebook->GetCurrentPage());
+    if(workspace) { workspace->RunFrequencyResponse(); }
 }
 void MainFrame::OnHarmDistortionsClick(wxRibbonButtonBarEvent& event)
 {
diff --git a/Project/PowerElement.h b/Project/PowerElement.h
index d2b13e7..031834e 100644
--- a/Project/PowerElement.h
+++ b/Project/PowerElement.h
@@ -24,7 +24,7 @@
 /**
  * @enum ElectricalUnit
  * @brief Electrical units.
-*/
+ */
 enum ElectricalUnit {
     UNIT_PU = 0, /**< Per unit (p.u.) */
     UNIT_V,      /**< Volt */
@@ -51,7 +51,7 @@ enum ElectricalUnit {
 /**
  * @enum FaultData
  * @brief Information about fault (type and location).
-*/
+ */
 enum FaultData {
     FAULT_THREEPHASE = 0, /**< Three-phase fault */
     FAULT_2LINE,          /**< Line-to-line fault */
@@ -65,7 +65,7 @@ enum FaultData {
 /**
  * @enum SwitchingType
  * @brief Type of switching.
-*/
+ */
 enum SwitchingType {
     SW_INSERT = 0, /**< Insert element */
     SW_REMOVE      /**< Remove element */
@@ -74,7 +74,7 @@ enum SwitchingType {
 /**
  * @enum PowerFlowDirection
  * @brief Direction of power flow arrows.
-*/
+ */
 enum PowerFlowDirection {
     PF_NONE = 0,     /**< No direction (no arrows printed) */
     PF_TO_BUS,       /**< Element to bus */
@@ -83,6 +83,11 @@ enum PowerFlowDirection {
     PF_BUS2_TO_BUS1  /**< Second bus to first bus (branch elements) */
 };
 
+enum PlotStudy {
+    STABILITY = 0, /**< Stability studies */
+    FREQRESPONSE   /**< Frequency resonse (Harmonics) */
+};
+
 /**
  * @class SwitchingData
  * @author Thales Lima Oliveira
@@ -195,7 +200,7 @@ class PowerElement : public Element
      * @param plotData Plot data to be filled.
      * @return true if the plot data was successfully filled, false otherwise.
      */
-    virtual bool GetPlotData(ElementPlotData& plotData) { return false; }
+    virtual bool GetPlotData(ElementPlotData& plotData, PlotStudy study = STABILITY) { return false; }
     /**
      * @brief Check if the power element have dynamic event.
      * @return true if the element have dynamic an event, false otherwise.
@@ -207,7 +212,7 @@ class PowerElement : public Element
      */
     virtual void SetDynamicEvent(bool dynEvent = true) { m_dynEvent = dynEvent; }
     virtual double GetValueFromUnit(double value, ElectricalUnit valueUnit);
-    
+
     virtual void SaveCADProperties(rapidxml::xml_document<>& doc, rapidxml::xml_node<>* elementNode);
     virtual void SaveSwitchingData(rapidxml::xml_document<>& doc, rapidxml::xml_node<>* electricalNode);
     virtual bool OpenElement(rapidxml::xml_node<>* elementNode, std::vector<Element*> parentList) { return true; }
diff --git a/Project/PowerQuality.cpp b/Project/PowerQuality.cpp
index 4efdc49..30969d9 100644
--- a/Project/PowerQuality.cpp
+++ b/Project/PowerQuality.cpp
@@ -23,133 +23,127 @@ void PowerQuality::CalculateHarmonicYbusList(double systemPowerBase)
     // Fill all Ybuses
     for(auto itYbus = m_harmYbusList.begin(), itYbusEnd = m_harmYbusList.end(); itYbus != itYbusEnd; ++itYbus) {
         HarmonicYbus harmYBus = *itYbus;
-        // Load
-        for(auto it = m_loadList.begin(), itEnd = m_loadList.end(); it != itEnd; ++it) {
-            Load* load = *it;
-            if(load->IsOnline()) {
-                int n = static_cast<Bus*>(load->GetParentList()[0])->GetElectricalData().number;
-                LoadElectricalData data = load->GetPUElectricalData(systemPowerBase);
-                wxMessageBox(wxString::Format("%f %f", data.activePower, data.reactivePower));
-                std::complex<double> yLoad =
-                    std::complex<double>(data.activePower, -data.reactivePower / harmYBus.order);
-                std::complex<double> v = static_cast<Bus*>(load->GetParentList()[0])->GetElectricalData().voltage;
-                yLoad /= (std::abs(v) * std::abs(v));
-                harmYBus.yBus[n][n] += yLoad;
-            }
+        CalculateHarmonicYbus(harmYBus.yBus, systemPowerBase, harmYBus.order);
+        *itYbus = harmYBus;
+    }
+}
+
+void PowerQuality::CalculateHarmonicYbus(std::vector<std::vector<std::complex<double> > >& yBus,
+                                         double systemPowerBase,
+                                         double order)
+{
+    // Load
+    for(auto it = m_loadList.begin(), itEnd = m_loadList.end(); it != itEnd; ++it) {
+        Load* load = *it;
+        if(load->IsOnline()) {
+            int n = static_cast<Bus*>(load->GetParentList()[0])->GetElectricalData().number;
+            LoadElectricalData data = load->GetPUElectricalData(systemPowerBase);
+            std::complex<double> yLoad = std::complex<double>(data.activePower, -data.reactivePower / order);
+            std::complex<double> v = static_cast<Bus*>(load->GetParentList()[0])->GetElectricalData().voltage;
+            yLoad /= (std::abs(v) * std::abs(v));
+            yBus[n][n] += yLoad;
         }
+    }
 
-        // Capacitor
-        for(auto it = m_capacitorList.begin(), itEnd = m_capacitorList.end(); it != itEnd; ++it) {
-            Capacitor* capacitor = *it;
-            if(capacitor->IsOnline()) {
-                int n = static_cast<Bus*>(capacitor->GetParentList()[0])->GetElectricalData().number;
-                CapacitorElectricalData data = capacitor->GetPUElectricalData(systemPowerBase);
-                harmYBus.yBus[n][n] += std::complex<double>(0.0, data.reactivePower) * harmYBus.order;
-            }
+    // Capacitor
+    for(auto it = m_capacitorList.begin(), itEnd = m_capacitorList.end(); it != itEnd; ++it) {
+        Capacitor* capacitor = *it;
+        if(capacitor->IsOnline()) {
+            int n = static_cast<Bus*>(capacitor->GetParentList()[0])->GetElectricalData().number;
+            CapacitorElectricalData data = capacitor->GetPUElectricalData(systemPowerBase);
+            yBus[n][n] += std::complex<double>(0.0, data.reactivePower) * order;
         }
+    }
 
-        // Inductor
-        for(auto it = m_inductorList.begin(), itEnd = m_inductorList.end(); it != itEnd; ++it) {
-            Inductor* inductor = *it;
-            if(inductor->IsOnline()) {
-                int n = static_cast<Bus*>(inductor->GetParentList()[0])->GetElectricalData().number;
-                InductorElectricalData data = inductor->GetPUElectricalData(systemPowerBase);
-                harmYBus.yBus[n][n] += std::complex<double>(0.0, -data.reactivePower) / harmYBus.order;
-            }
+    // Inductor
+    for(auto it = m_inductorList.begin(), itEnd = m_inductorList.end(); it != itEnd; ++it) {
+        Inductor* inductor = *it;
+        if(inductor->IsOnline()) {
+            int n = static_cast<Bus*>(inductor->GetParentList()[0])->GetElectricalData().number;
+            InductorElectricalData data = inductor->GetPUElectricalData(systemPowerBase);
+            yBus[n][n] += std::complex<double>(0.0, -data.reactivePower) / order;
         }
+    }
 
-        // Power line
-        for(auto it = m_lineList.begin(), itEnd = m_lineList.end(); it != itEnd; ++it) {
-            Line* line = *it;
-            if(line->IsOnline()) {
-                LineElectricalData data = line->GetPUElectricalData(systemPowerBase);
+    // Power line
+    for(auto it = m_lineList.begin(), itEnd = m_lineList.end(); it != itEnd; ++it) {
+        Line* line = *it;
+        if(line->IsOnline()) {
+            LineElectricalData data = line->GetPUElectricalData(systemPowerBase);
 
-                int n1 = static_cast<Bus*>(line->GetParentList()[0])->GetElectricalData().number;
-                int n2 = static_cast<Bus*>(line->GetParentList()[1])->GetElectricalData().number;
+            int n1 = static_cast<Bus*>(line->GetParentList()[0])->GetElectricalData().number;
+            int n2 = static_cast<Bus*>(line->GetParentList()[1])->GetElectricalData().number;
 
-                harmYBus.yBus[n1][n2] -=
-                    1.0 / std::complex<double>(data.resistance, data.indReactance * harmYBus.order);
-                harmYBus.yBus[n2][n1] -=
-                    1.0 / std::complex<double>(data.resistance, data.indReactance * harmYBus.order);
+            yBus[n1][n2] -= 1.0 / std::complex<double>(data.resistance, data.indReactance * order);
+            yBus[n2][n1] -= 1.0 / std::complex<double>(data.resistance, data.indReactance * order);
 
-                harmYBus.yBus[n1][n1] +=
-                    1.0 / std::complex<double>(data.resistance, data.indReactance * harmYBus.order);
-                harmYBus.yBus[n2][n2] +=
-                    1.0 / std::complex<double>(data.resistance, data.indReactance * harmYBus.order);
+            yBus[n1][n1] += 1.0 / std::complex<double>(data.resistance, data.indReactance * order);
+            yBus[n2][n2] += 1.0 / std::complex<double>(data.resistance, data.indReactance * order);
 
-                harmYBus.yBus[n1][n1] += std::complex<double>(0.0, (data.capSusceptance * harmYBus.order) / 2.0);
-                harmYBus.yBus[n2][n2] += std::complex<double>(0.0, (data.capSusceptance * harmYBus.order) / 2.0);
-            }
+            yBus[n1][n1] += std::complex<double>(0.0, (data.capSusceptance * order) / 2.0);
+            yBus[n2][n2] += std::complex<double>(0.0, (data.capSusceptance * order) / 2.0);
         }
+    }
 
-        // Transformer
-        for(auto it = m_transformerList.begin(), itEnd = m_transformerList.end(); it != itEnd; ++it) {
-            Transformer* transformer = *it;
+    // Transformer
+    for(auto it = m_transformerList.begin(), itEnd = m_transformerList.end(); it != itEnd; ++it) {
+        Transformer* transformer = *it;
 
-            if(transformer->IsOnline()) {
-                TransformerElectricalData data = transformer->GetPUElectricalData(systemPowerBase);
+        if(transformer->IsOnline()) {
+            TransformerElectricalData data = transformer->GetPUElectricalData(systemPowerBase);
 
-                int n1 = static_cast<Bus*>(transformer->GetParentList()[0])->GetElectricalData().number;
-                int n2 = static_cast<Bus*>(transformer->GetParentList()[1])->GetElectricalData().number;
+            int n1 = static_cast<Bus*>(transformer->GetParentList()[0])->GetElectricalData().number;
+            int n2 = static_cast<Bus*>(transformer->GetParentList()[1])->GetElectricalData().number;
 
-                // If the transformer have nominal turns ratio (1.0) and no phase shifting, it will be modelled as
-                // series impedance.
-                if(data.turnsRatio == 1.0 && data.phaseShift == 0.0) {
-                    harmYBus.yBus[n1][n2] +=
-                        -1.0 / std::complex<double>(data.resistance, data.indReactance * harmYBus.order);
-                    harmYBus.yBus[n2][n1] +=
-                        -1.0 / std::complex<double>(data.resistance, data.indReactance * harmYBus.order);
+            // If the transformer have nominal turns ratio (1.0) and no phase shifting, it will be modelled as
+            // series impedance.
+            if(data.turnsRatio == 1.0 && data.phaseShift == 0.0) {
+                yBus[n1][n2] += -1.0 / std::complex<double>(data.resistance, data.indReactance * order);
+                yBus[n2][n1] += -1.0 / std::complex<double>(data.resistance, data.indReactance * order);
 
-                    harmYBus.yBus[n1][n1] +=
-                        1.0 / std::complex<double>(data.resistance, data.indReactance * harmYBus.order);
-                    harmYBus.yBus[n2][n2] +=
-                        1.0 / std::complex<double>(data.resistance, data.indReactance * harmYBus.order);
-                }
-                // If the transformer have no-nominal turn ratio and/or phase shifting, it will be modelled in a
-                // different way (see references).
-                //[Ref. 1: Elementos de analise de sistemas de potencia - Stevenson - pg. 232]
-                //[Ref. 2:
-                // http://www.ee.washington.edu/research/real/Library/Reports/Tap_Adjustments_in_AC_Load_Flows.pdf]
-                // [Ref. 3: http://www.columbia.edu/~dano/courses/power/notes/power/andersson1.pdf]
-                else {
-                    // Complex turns ratio
-                    double radPhaseShift = wxDegToRad(data.phaseShift);
-                    std::complex<double> a = std::complex<double>(data.turnsRatio * std::cos(radPhaseShift),
-                                                                  -data.turnsRatio * std::sin(radPhaseShift));
-
-                    // Transformer admitance
-                    std::complex<double> y =
-                        1.0 / std::complex<double>(data.resistance, data.indReactance * harmYBus.order);
-
-                    harmYBus.yBus[n1][n1] += y / (std::pow(std::abs(a), 2.0));
-                    harmYBus.yBus[n1][n2] += -(y / std::conj(a));
-                    harmYBus.yBus[n2][n1] += -(y / a);
-                    harmYBus.yBus[n2][n2] += y;
-                }
+                yBus[n1][n1] += 1.0 / std::complex<double>(data.resistance, data.indReactance * order);
+                yBus[n2][n2] += 1.0 / std::complex<double>(data.resistance, data.indReactance * order);
             }
-        }
+            // If the transformer have no-nominal turn ratio and/or phase shifting, it will be modelled in a
+            // different way (see references).
+            //[Ref. 1: Elementos de analise de sistemas de potencia - Stevenson - pg. 232]
+            //[Ref. 2:
+            // http://www.ee.washington.edu/research/real/Library/Reports/Tap_Adjustments_in_AC_Load_Flows.pdf]
+            // [Ref. 3: http://www.columbia.edu/~dano/courses/power/notes/power/andersson1.pdf]
+            else {
+                // Complex turns ratio
+                double radPhaseShift = wxDegToRad(data.phaseShift);
+                std::complex<double> a = std::complex<double>(data.turnsRatio * std::cos(radPhaseShift),
+                                                              -data.turnsRatio * std::sin(radPhaseShift));
+
+                // Transformer admitance
+                std::complex<double> y = 1.0 / std::complex<double>(data.resistance, data.indReactance * order);
 
-        // Synchronous generator
-        for(auto it = m_syncGeneratorList.begin(), itEnd = m_syncGeneratorList.end(); it != itEnd; ++it) {
-            SyncGenerator* syncGenerator = *it;
-            if(syncGenerator->IsOnline()) {
-                int n = static_cast<Bus*>(syncGenerator->GetParentList()[0])->GetElectricalData().number;
-                SyncGeneratorElectricalData data = syncGenerator->GetPUElectricalData(systemPowerBase);
-                harmYBus.yBus[n][n] +=
-                    1.0 / std::complex<double>(data.positiveResistance, data.positiveReactance * harmYBus.order);
+                yBus[n1][n1] += y / (std::pow(std::abs(a), 2.0));
+                yBus[n1][n2] += -(y / std::conj(a));
+                yBus[n2][n1] += -(y / a);
+                yBus[n2][n2] += y;
             }
         }
-        // Synchronous motor
-        for(auto it = m_syncMotorList.begin(), itEnd = m_syncMotorList.end(); it != itEnd; ++it) {
-            SyncMotor* syncMotor = *it;
-            if(syncMotor->IsOnline()) {
-                int n = static_cast<Bus*>(syncMotor->GetParentList()[0])->GetElectricalData().number;
-                SyncMotorElectricalData data = syncMotor->GetPUElectricalData(systemPowerBase);
-                harmYBus.yBus[n][n] +=
-                    1.0 / std::complex<double>(data.positiveResistance, data.positiveReactance * harmYBus.order);
-            }
+    }
+
+    // Synchronous generator
+    for(auto it = m_syncGeneratorList.begin(), itEnd = m_syncGeneratorList.end(); it != itEnd; ++it) {
+        SyncGenerator* syncGenerator = *it;
+        if(syncGenerator->IsOnline()) {
+            int n = static_cast<Bus*>(syncGenerator->GetParentList()[0])->GetElectricalData().number;
+            SyncGeneratorElectricalData data = syncGenerator->GetPUElectricalData(systemPowerBase);
+            yBus[n][n] += 1.0 / std::complex<double>(data.positiveResistance, data.positiveReactance * order);
+        }
+    }
+    // Synchronous motor
+    for(auto it = m_syncMotorList.begin(), itEnd = m_syncMotorList.end(); it != itEnd; ++it) {
+        SyncMotor* syncMotor = *it;
+        if(syncMotor->IsOnline()) {
+            int n = static_cast<Bus*>(syncMotor->GetParentList()[0])->GetElectricalData().number;
+            SyncMotorElectricalData data = syncMotor->GetPUElectricalData(systemPowerBase);
+            yBus[n][n] += 1.0 / std::complex<double>(data.positiveResistance, data.positiveReactance * order);
         }
-        *itYbus = harmYBus;
     }
 }
 
@@ -207,7 +201,7 @@ bool PowerQuality::CalculateDistortions(double systemPowerBase)
     for(unsigned int i = 0; i < m_harmYbusList.size(); ++i) {
         vHarmList.push_back(GaussianElimination(m_harmYbusList[i].yBus, iHarmInjList[i]));
     }
-    
+
     for(auto it = m_busList.begin(), itEnd = m_busList.end(); it != itEnd; ++it) {
         Bus* bus = *it;
         auto data = bus->GetElectricalData();
@@ -219,9 +213,10 @@ bool PowerQuality::CalculateDistortions(double systemPowerBase)
             data.harmonicVoltage.push_back(vHarmList[i][data.number]);
             data.harmonicOrder.push_back(static_cast<int>(harmOrders[i]));
         }
-        //distortion = std::sqrt(distortion) / std::abs(data.voltage);
+        // distortion = std::sqrt(distortion) / std::abs(data.voltage);
         thd = std::sqrt(thd) * 100.0;
         data.thd = thd;
+        bus->SetElectricalData(data);
     }
 
     return true;
@@ -256,3 +251,58 @@ std::vector<double> PowerQuality::GetHarmonicOrdersList()
     }
     return doubleHarmOrder;
 }
+
+bool PowerQuality::CalculateFrequencyResponse(double systemFreq,
+                                              double initFreq,
+                                              double endFreq,
+                                              double stepFreq,
+                                              double systemPowerBase)
+{
+    // Clear all previous data
+    for(unsigned int i = 0; i < m_busList.size(); i++) {
+        auto data = m_busList[i]->GetElectricalData();
+        data.absImpedanceVector.clear();
+        data.absImpedanceVector.shrink_to_fit();
+        m_busList[i]->SetElectricalData(data);
+    }
+
+    // Create and fill with zeros the YBus
+    std::vector<std::vector<std::complex<double> > > yBus;
+    for(unsigned int i = 0; i < m_busList.size(); i++) {
+        std::vector<std::complex<double> > line;
+        for(unsigned int j = 0; j < m_busList.size(); j++) { line.push_back(std::complex<double>(0.0, 0.0)); }
+        yBus.push_back(line);
+    }
+    // Create and fill with zoros the injected current vector
+    std::vector<std::complex<double> > iInj;
+    for(unsigned int i = 0; i < m_busList.size(); i++) { iInj.push_back(std::complex<double>(10.0, 0.0)); }
+
+    if(initFreq < 1e-6) initFreq = stepFreq;
+    double currentFreq = initFreq;
+    while(currentFreq <= endFreq) {
+        m_frequencyList.push_back(currentFreq);
+
+        double order = currentFreq / systemFreq;
+
+        // Fill YBus with zeros
+        for(unsigned int i = 0; i < m_busList.size(); i++) {
+            for(unsigned int j = 0; j < m_busList.size(); j++) { yBus[i][j] = std::complex<double>(0.0, 0.0); }
+        }
+
+        CalculateHarmonicYbus(yBus, systemPowerBase, order);
+
+        for(unsigned int i = 0; i < m_busList.size(); i++) {
+            auto data = m_busList[i]->GetElectricalData();
+            iInj[data.number] = std::complex<double>(1.0, 0.0);
+
+            auto zh = GaussianElimination(yBus, iInj);
+
+            data.absImpedanceVector.push_back(std::abs(zh[data.number]));
+            m_busList[i]->SetElectricalData(data);
+            iInj[data.number] = std::complex<double>(0.0, 0.0);
+        }
+
+        currentFreq += stepFreq;
+    }
+    return false;
+}
diff --git a/Project/PowerQuality.h b/Project/PowerQuality.h
index ad47884..6c443e3 100644
--- a/Project/PowerQuality.h
+++ b/Project/PowerQuality.h
@@ -22,16 +22,26 @@ class PowerQuality : public ElectricCalculation
     };
 
     PowerQuality();
-    PowerQuality(std::vector<Element*> elementList);
+    PowerQuality(std::vector<Element *> elementList);
     ~PowerQuality();
-    
+
     virtual void CalculateHarmonicYbusList(double systemPowerBase = 100e6);
+    virtual void CalculateHarmonicYbus(std::vector<std::vector<std::complex<double> > > &yBus,
+                                       double systemPowerBase,
+                                       double order);
 
     virtual bool CalculateDistortions(double systemPowerBase = 100e6);
+    virtual bool CalculateFrequencyResponse(double systemFreq = 60.0,
+                                            double initFreq = 0.0,
+                                            double endFreq = 1500.0,
+                                            double stepFreq = 1.0,
+                                            double systemPowerBase = 100e6);
     virtual std::vector<double> GetHarmonicOrdersList();
+    virtual std::vector<double> GetFrequencies() { return m_frequencyList; }
 
    protected:
     std::vector<HarmonicYbus> m_harmYbusList;
+    std::vector<double> m_frequencyList;
 };
 
 #endif  // POWERQUALITY_H
diff --git a/Project/PropertiesData.h b/Project/PropertiesData.h
index 127eb59..926b90b 100644
--- a/Project/PropertiesData.h
+++ b/Project/PropertiesData.h
@@ -31,6 +31,7 @@ struct SimulationData {
     ElectricalUnit basePowerUnit = UNIT_MVA;
     bool faultAfterPowerFlow = false;
     bool scPowerAfterPowerFlow = false;
+    bool harmDistortionAfterPowerFlow = false;
 
     // Power flow
     PowerFlowMethod powerFlowMethod = GAUSS_SEIDEL;
diff --git a/Project/PropertiesForm.wxcp b/Project/PropertiesForm.wxcp
index 3962cd0..f4f531a 100644
--- a/Project/PropertiesForm.wxcp
+++ b/Project/PropertiesForm.wxcp
@@ -1,7 +1,7 @@
 {
  "metadata": {
   "m_generatedFilesDir": ".",
-  "m_objCounter": 815,
+  "m_objCounter": 816,
   "m_includeFiles": [],
   "m_bitmapFunction": "wxCDAD0InitBitmapResources",
   "m_bitmapsFile": "PropertiesFormBitmaps.cpp",
@@ -1531,6 +1531,299 @@
                 }]
               }]
             }, {
+             "m_type": 4401,
+             "proportion": 0,
+             "border": 5,
+             "gbSpan": "1,1",
+             "gbPosition": "0,0",
+             "m_styles": [],
+             "m_sizerFlags": ["wxEXPAND"],
+             "m_properties": [{
+               "type": "string",
+               "m_label": "Minimum Size:",
+               "m_value": "-1,-1"
+              }, {
+               "type": "string",
+               "m_label": "Name:",
+               "m_value": "boxSizerLvl3_2"
+              }, {
+               "type": "string",
+               "m_label": "Style:",
+               "m_value": ""
+              }, {
+               "type": "choice",
+               "m_label": "Orientation:",
+               "m_selection": 0,
+               "m_options": ["wxVERTICAL", "wxHORIZONTAL"]
+              }],
+             "m_events": [],
+             "m_children": [{
+               "m_type": 4405,
+               "proportion": 0,
+               "border": 5,
+               "gbSpan": "1,1",
+               "gbPosition": "0,0",
+               "m_styles": [],
+               "m_sizerFlags": ["wxLEFT", "wxRIGHT", "wxTOP", "wxALIGN_CENTER_VERTICAL"],
+               "m_properties": [{
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+                }, {
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+                 "m_value": "-1,-1"
+                }, {
+                 "type": "string",
+                 "m_label": "Name:",
+                 "m_value": "m_staticTextFreq"
+                }, {
+                 "type": "multi-string",
+                 "m_label": "Tooltip:",
+                 "m_value": ""
+                }, {
+                 "type": "colour",
+                 "m_label": "Bg Colour:",
+                 "colour": "<Default>"
+                }, {
+                 "type": "colour",
+                 "m_label": "Fg Colour:",
+                 "colour": "<Default>"
+                }, {
+                 "type": "font",
+                 "m_label": "Font:",
+                 "m_value": ""
+                }, {
+                 "type": "bool",
+                 "m_label": "Hidden",
+                 "m_value": false
+                }, {
+                 "type": "bool",
+                 "m_label": "Disabled",
+                 "m_value": false
+                }, {
+                 "type": "bool",
+                 "m_label": "Focused",
+                 "m_value": false
+                }, {
+                 "type": "string",
+                 "m_label": "Class Name:",
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+                }, {
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+                 "m_value": ""
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+                 "m_label": "Style:",
+                 "m_value": ""
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+                 "m_label": "Label:",
+                 "m_value": "System frequency"
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+                 "m_properties": [{
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+                   "m_label": "Value:",
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+                   "m_label": "Max Length:",
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+                   "type": "bool",
+                   "m_label": "Auto Complete Files:",
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+                   "m_label": "Bg Colour:",
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+                   "m_label": "Fg Colour:",
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+                   "type": "font",
+                   "m_label": "Font:",
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+                   "m_value": false
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+                   "m_label": "Disabled",
+                   "m_value": false
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+                   "m_label": "Focused",
+                   "m_value": false
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+                   "m_label": "Class Name:",
+                   "m_value": ""
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+                   "m_label": "Include File:",
+                   "m_value": ""
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+                   "m_label": "Style:",
+                   "m_value": ""
+                  }, {
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+                   "m_label": "Label:",
+                   "m_value": "Hz"
+                  }, {
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+                   "m_value": "-1"
+                  }],
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+                 "m_children": []
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@@ -1711,6 +2004,81 @@
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+                 "m_value": "-1,-1"
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+                 "m_label": "Name:",
+                 "m_value": "m_checkBoxTHDAfterPF"
+                }, {
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+                 "m_label": "Tooltip:",
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+                 "m_label": "Bg Colour:",
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+                 "m_label": "Fg Colour:",
+                 "colour": "<Default>"
+                }, {
+                 "type": "font",
+                 "m_label": "Font:",
+                 "m_value": ""
+                }, {
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+                 "m_label": "Hidden",
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+                 "m_label": "Disabled",
+                 "m_value": false
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+                 "type": "bool",
+                 "m_label": "Focused",
+                 "m_value": false
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+                 "m_label": "Class Name:",
+                 "m_value": ""
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+                 "m_label": "Style:",
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+                }, {
+                 "type": "string",
+                 "m_label": "Label:",
+                 "m_value": "Calculate harmonic distortion after power flow"
+                }, {
+                 "type": "bool",
+                 "m_label": "Value:",
+                 "m_value": true
+                }],
+               "m_events": [],
+               "m_children": []
               }]
             }]
           }]
@@ -3660,299 +4028,6 @@
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-                     "m_label": "Auto Complete Directories:",
-                     "m_value": false
-                    }, {
-                     "type": "bool",
-                     "m_label": "Auto Complete Files:",
-                     "m_value": false
-                    }],
-                   "m_events": [],
-                   "m_children": []
-                  }, {
-                   "m_type": 4405,
-                   "proportion": 0,
-                   "border": 5,
-                   "gbSpan": "1,1",
-                   "gbPosition": "0,0",
-                   "m_styles": [],
-                   "m_sizerFlags": ["wxLEFT", "wxRIGHT", "wxBOTTOM", "wxALIGN_CENTER_VERTICAL"],
-                   "m_properties": [{
-                     "type": "winid",
-                     "m_label": "ID:",
-                     "m_winid": "wxID_ANY"
-                    }, {
-                     "type": "string",
-                     "m_label": "Size:",
-                     "m_value": "-1,-1"
-                    }, {
-                     "type": "string",
-                     "m_label": "Minimum Size:",
-                     "m_value": "-1,-1"
-                    }, {
-                     "type": "string",
-                     "m_label": "Name:",
-                     "m_value": "m_staticTextFreqUnit"
-                    }, {
-                     "type": "multi-string",
-                     "m_label": "Tooltip:",
-                     "m_value": ""
-                    }, {
-                     "type": "colour",
-                     "m_label": "Bg Colour:",
-                     "colour": "<Default>"
-                    }, {
-                     "type": "colour",
-                     "m_label": "Fg Colour:",
-                     "colour": "<Default>"
-                    }, {
-                     "type": "font",
-                     "m_label": "Font:",
-                     "m_value": ""
-                    }, {
-                     "type": "bool",
-                     "m_label": "Hidden",
-                     "m_value": false
-                    }, {
-                     "type": "bool",
-                     "m_label": "Disabled",
-                     "m_value": false
-                    }, {
-                     "type": "bool",
-                     "m_label": "Focused",
-                     "m_value": false
-                    }, {
-                     "type": "string",
-                     "m_label": "Class Name:",
-                     "m_value": ""
-                    }, {
-                     "type": "string",
-                     "m_label": "Include File:",
-                     "m_value": ""
-                    }, {
-                     "type": "string",
-                     "m_label": "Style:",
-                     "m_value": ""
-                    }, {
-                     "type": "multi-string",
-                     "m_label": "Label:",
-                     "m_value": "Hz"
-                    }, {
-                     "type": "string",
-                     "m_label": "Wrap:",
-                     "m_value": "-1"
-                    }],
-                   "m_events": [],
-                   "m_children": []
-                  }]
-                }]
-              }, {
-               "m_type": 4401,
-               "proportion": 0,
-               "border": 5,
-               "gbSpan": "1,1",
-               "gbPosition": "0,0",
-               "m_styles": [],
-               "m_sizerFlags": ["wxEXPAND"],
-               "m_properties": [{
-                 "type": "string",
-                 "m_label": "Minimum Size:",
-                 "m_value": "-1,-1"
-                }, {
-                 "type": "string",
-                 "m_label": "Name:",
                  "m_value": "boxSizerLvl3_8"
                 }, {
                  "type": "string",
diff --git a/Project/PropertiesFormBase.cpp b/Project/PropertiesFormBase.cpp
index 62f2c0d..e76b211 100644
--- a/Project/PropertiesFormBase.cpp
+++ b/Project/PropertiesFormBase.cpp
@@ -190,6 +190,33 @@ SimulationsSettingsFormBase::SimulationsSettingsFormBase(wxWindow* parent,
 
     boxSizerLvl4_1->Add(m_choiceBasePower, 0, wxLEFT | wxRIGHT | wxBOTTOM, WXC_FROM_DIP(5));
 
+    wxBoxSizer* boxSizerLvl3_2 = new wxBoxSizer(wxVERTICAL);
+
+    boxSizerLvl2_1->Add(boxSizerLvl3_2, 0, wxEXPAND, WXC_FROM_DIP(5));
+
+    m_staticTextFreq = new wxStaticText(m_panelGeneral, wxID_ANY, _("System frequency"), wxDefaultPosition,
+                                        wxDLG_UNIT(m_panelGeneral, wxSize(-1, -1)), 0);
+
+    boxSizerLvl3_2->Add(m_staticTextFreq, 0, wxLEFT | wxRIGHT | wxTOP | wxALIGN_CENTER_VERTICAL, WXC_FROM_DIP(5));
+
+    wxBoxSizer* boxSizerLvl4_5 = new wxBoxSizer(wxHORIZONTAL);
+
+    boxSizerLvl3_2->Add(boxSizerLvl4_5, 0, wxEXPAND, WXC_FROM_DIP(5));
+
+    m_textCtrlFreq = new wxTextCtrl(m_panelGeneral, wxID_ANY, wxT("60,0"), wxDefaultPosition,
+                                    wxDLG_UNIT(m_panelGeneral, wxSize(-1, -1)), 0);
+#if wxVERSION_NUMBER >= 3000
+    m_textCtrlFreq->SetHint(wxT(""));
+#endif
+
+    boxSizerLvl4_5->Add(m_textCtrlFreq, 1, wxLEFT | wxRIGHT | wxBOTTOM | wxALIGN_CENTER_VERTICAL, WXC_FROM_DIP(5));
+
+    m_staticTextFreqUnit = new wxStaticText(m_panelGeneral, wxID_ANY, _("Hz"), wxDefaultPosition,
+                                            wxDLG_UNIT(m_panelGeneral, wxSize(-1, -1)), 0);
+
+    boxSizerLvl4_5->Add(m_staticTextFreqUnit, 0, wxLEFT | wxRIGHT | wxBOTTOM | wxALIGN_CENTER_VERTICAL,
+                        WXC_FROM_DIP(5));
+
     wxStaticBoxSizer* staticBoxSizerLvl3_2 =
         new wxStaticBoxSizer(new wxStaticBox(m_panelGeneral, wxID_ANY, _("Continuous calculation")), wxVERTICAL);
 
@@ -208,6 +235,12 @@ SimulationsSettingsFormBase::SimulationsSettingsFormBase(wxWindow* parent,
 
     staticBoxSizerLvl3_2->Add(m_checkBoxSCPowerAfterPF, 0, wxALL, WXC_FROM_DIP(5));
 
+    m_checkBoxTHDAfterPF = new wxCheckBox(m_panelGeneral, wxID_ANY, _("Calculate harmonic distortion after power flow"),
+                                          wxDefaultPosition, wxDLG_UNIT(m_panelGeneral, wxSize(-1, -1)), 0);
+    m_checkBoxTHDAfterPF->SetValue(true);
+
+    staticBoxSizerLvl3_2->Add(m_checkBoxTHDAfterPF, 0, wxALL, WXC_FROM_DIP(5));
+
     m_panelPF =
         new wxPanel(m_notebook, wxID_ANY, wxDefaultPosition, wxDLG_UNIT(m_notebook, wxSize(-1, -1)), wxTAB_TRAVERSAL);
     m_notebook->AddPage(m_panelPF, _("Power flow"), false);
@@ -385,33 +418,6 @@ SimulationsSettingsFormBase::SimulationsSettingsFormBase(wxWindow* parent,
 
     boxSizerLvl4_7->Add(m_staticTextSec_2, 0, wxLEFT | wxRIGHT | wxBOTTOM | wxALIGN_CENTER_VERTICAL, WXC_FROM_DIP(5));
 
-    wxBoxSizer* boxSizerLvl3_5 = new wxBoxSizer(wxVERTICAL);
-
-    gridSizerLvl_2_3->Add(boxSizerLvl3_5, 0, wxEXPAND, WXC_FROM_DIP(5));
-
-    m_staticTextFreq = new wxStaticText(m_panelStability, wxID_ANY, _("System frequency"), wxDefaultPosition,
-                                        wxDLG_UNIT(m_panelStability, wxSize(-1, -1)), 0);
-
-    boxSizerLvl3_5->Add(m_staticTextFreq, 0, wxLEFT | wxRIGHT | wxTOP | wxALIGN_CENTER_VERTICAL, WXC_FROM_DIP(5));
-
-    wxBoxSizer* boxSizerLvl4_5 = new wxBoxSizer(wxHORIZONTAL);
-
-    boxSizerLvl3_5->Add(boxSizerLvl4_5, 0, wxEXPAND, WXC_FROM_DIP(5));
-
-    m_textCtrlFreq = new wxTextCtrl(m_panelStability, wxID_ANY, wxT("60,0"), wxDefaultPosition,
-                                    wxDLG_UNIT(m_panelStability, wxSize(-1, -1)), 0);
-#if wxVERSION_NUMBER >= 3000
-    m_textCtrlFreq->SetHint(wxT(""));
-#endif
-
-    boxSizerLvl4_5->Add(m_textCtrlFreq, 1, wxLEFT | wxRIGHT | wxBOTTOM | wxALIGN_CENTER_VERTICAL, WXC_FROM_DIP(5));
-
-    m_staticTextFreqUnit = new wxStaticText(m_panelStability, wxID_ANY, _("Hz"), wxDefaultPosition,
-                                            wxDLG_UNIT(m_panelStability, wxSize(-1, -1)), 0);
-
-    boxSizerLvl4_5->Add(m_staticTextFreqUnit, 0, wxLEFT | wxRIGHT | wxBOTTOM | wxALIGN_CENTER_VERTICAL,
-                        WXC_FROM_DIP(5));
-
     wxBoxSizer* boxSizerLvl3_8 = new wxBoxSizer(wxVERTICAL);
 
     gridSizerLvl_2_3->Add(boxSizerLvl3_8, 0, wxEXPAND, WXC_FROM_DIP(5));
diff --git a/Project/PropertiesFormBase.h b/Project/PropertiesFormBase.h
index f0a579b..d7d4dce 100644
--- a/Project/PropertiesFormBase.h
+++ b/Project/PropertiesFormBase.h
@@ -7,32 +7,32 @@
 #ifndef _PSP_PROJECT_PROPERTIESFORM_BASE_CLASSES_H
 #define _PSP_PROJECT_PROPERTIESFORM_BASE_CLASSES_H
 
-#include <wx/settings.h>
-#include <wx/xrc/xmlres.h>
-#include <wx/xrc/xh_bmp.h>
+#include <wx/arrstr.h>
+#include <wx/artprov.h>
+#include <wx/button.h>
+#include <wx/checkbox.h>
+#include <wx/choice.h>
 #include <wx/dialog.h>
+#include <wx/filepicker.h>
+#include <wx/grid.h>
+#include <wx/hyperlink.h>
 #include <wx/iconbndl.h>
-#include <wx/artprov.h>
-#include <wx/sizer.h>
+#include <wx/imaglist.h>
 #include <wx/notebook.h>
 #include <wx/panel.h>
-#include <wx/imaglist.h>
+#include <wx/richtext/richtextctrl.h>
+#include <wx/settings.h>
+#include <wx/sizer.h>
+#include <wx/statbmp.h>
+#include <wx/statbox.h>
 #include <wx/stattext.h>
-#include <wx/choice.h>
-#include <wx/arrstr.h>
-#include <wx/button.h>
 #include <wx/textctrl.h>
-#include <wx/statbox.h>
-#include <wx/checkbox.h>
-#include <wx/statbmp.h>
-#include <wx/grid.h>
-#include <wx/richtext/richtextctrl.h>
-#include <wx/hyperlink.h>
-#include <wx/filepicker.h>
+#include <wx/xrc/xh_bmp.h>
+#include <wx/xrc/xmlres.h>
 #if wxVERSION_NUMBER >= 2900
 #include <wx/persist.h>
-#include <wx/persist/toplevel.h>
 #include <wx/persist/bookctrl.h>
+#include <wx/persist/toplevel.h>
 #include <wx/persist/treebook.h>
 #endif
 
@@ -45,10 +45,9 @@
 #define WXC_FROM_DIP(x) x
 #endif
 
-
 class GeneralPropertiesFormBase : public wxDialog
 {
-protected:
+   protected:
     wxNotebook* m_notebook;
     wxPanel* m_panelGeneral;
     wxStaticText* m_staticTextLanguage;
@@ -58,11 +57,11 @@ protected:
     wxButton* m_buttonOK;
     wxButton* m_buttonCancel;
 
-protected:
+   protected:
     virtual void OnButtonOKClick(wxCommandEvent& event) { event.Skip(); }
     virtual void OnButtonCancelClick(wxCommandEvent& event) { event.Skip(); }
 
-public:
+   public:
     wxStaticText* GetStaticTextLanguage() { return m_staticTextLanguage; }
     wxChoice* GetChoiceLanguage() { return m_choiceLanguage; }
     wxStaticText* GetStaticTextTheme() { return m_staticTextTheme; }
@@ -71,21 +70,29 @@ public:
     wxNotebook* GetNotebook() { return m_notebook; }
     wxButton* GetButtonOK() { return m_buttonOK; }
     wxButton* GetButtonCancel() { return m_buttonCancel; }
-    GeneralPropertiesFormBase(wxWindow* parent, wxWindowID id = wxID_ANY, const wxString& title = _("General settings"), const wxPoint& pos = wxDefaultPosition, const wxSize& size = wxSize(-1,-1), long style = wxDEFAULT_DIALOG_STYLE);
+    GeneralPropertiesFormBase(wxWindow* parent,
+                              wxWindowID id = wxID_ANY,
+                              const wxString& title = _("General settings"),
+                              const wxPoint& pos = wxDefaultPosition,
+                              const wxSize& size = wxSize(-1, -1),
+                              long style = wxDEFAULT_DIALOG_STYLE);
     virtual ~GeneralPropertiesFormBase();
 };
 
-
 class SimulationsSettingsFormBase : public wxDialog
 {
-protected:
+   protected:
     wxNotebook* m_notebook;
     wxPanel* m_panelGeneral;
     wxStaticText* m_staticTextBasePower;
     wxTextCtrl* m_textCtrlbasePower;
     wxChoice* m_choiceBasePower;
+    wxStaticText* m_staticTextFreq;
+    wxTextCtrl* m_textCtrlFreq;
+    wxStaticText* m_staticTextFreqUnit;
     wxCheckBox* m_checkBoxFaultAfterPF;
     wxCheckBox* m_checkBoxSCPowerAfterPF;
+    wxCheckBox* m_checkBoxTHDAfterPF;
     wxPanel* m_panelPF;
     wxStaticText* m_staticTextPFMethod;
     wxChoice* m_choicePFMethod;
@@ -105,9 +112,6 @@ protected:
     wxStaticText* m_staticTextTSimTime;
     wxTextCtrl* m_textCtrlSimTime;
     wxStaticText* m_staticTextSec_2;
-    wxStaticText* m_staticTextFreq;
-    wxTextCtrl* m_textCtrlFreq;
-    wxStaticText* m_staticTextFreqUnit;
     wxStaticText* m_staticTextTStabTolerance;
     wxTextCtrl* m_textCtrlStabTolerance;
     wxStaticText* m_staticTextTStabMaxIterations;
@@ -148,18 +152,22 @@ protected:
     wxButton* m_buttonOK;
     wxButton* m_buttonCancel;
 
-protected:
+   protected:
     virtual void OnPFMethodChoiceSelected(wxCommandEvent& event) { event.Skip(); }
     virtual void OnCheckboxUseCompLoadClick(wxCommandEvent& event) { event.Skip(); }
     virtual void OnButtonOKClick(wxCommandEvent& event) { event.Skip(); }
     virtual void OnButtonCancelClick(wxCommandEvent& event) { event.Skip(); }
 
-public:
+   public:
     wxStaticText* GetStaticTextBasePower() { return m_staticTextBasePower; }
     wxTextCtrl* GetTextCtrlbasePower() { return m_textCtrlbasePower; }
     wxChoice* GetChoiceBasePower() { return m_choiceBasePower; }
+    wxStaticText* GetStaticTextFreq() { return m_staticTextFreq; }
+    wxTextCtrl* GetTextCtrlFreq() { return m_textCtrlFreq; }
+    wxStaticText* GetStaticTextFreqUnit() { return m_staticTextFreqUnit; }
     wxCheckBox* GetCheckBoxFaultAfterPF() { return m_checkBoxFaultAfterPF; }
     wxCheckBox* GetCheckBoxSCPowerAfterPF() { return m_checkBoxSCPowerAfterPF; }
+    wxCheckBox* GetCheckBoxTHDAfterPF() { return m_checkBoxTHDAfterPF; }
     wxPanel* GetPanelGeneral() { return m_panelGeneral; }
     wxStaticText* GetStaticTextPFMethod() { return m_staticTextPFMethod; }
     wxChoice* GetChoicePFMethod() { return m_choicePFMethod; }
@@ -179,9 +187,6 @@ public:
     wxStaticText* GetStaticTextTSimTime() { return m_staticTextTSimTime; }
     wxTextCtrl* GetTextCtrlSimTime() { return m_textCtrlSimTime; }
     wxStaticText* GetStaticTextSec_2() { return m_staticTextSec_2; }
-    wxStaticText* GetStaticTextFreq() { return m_staticTextFreq; }
-    wxTextCtrl* GetTextCtrlFreq() { return m_textCtrlFreq; }
-    wxStaticText* GetStaticTextFreqUnit() { return m_staticTextFreqUnit; }
     wxStaticText* GetStaticTextTStabTolerance() { return m_staticTextTStabTolerance; }
     wxTextCtrl* GetTextCtrlStabTolerance() { return m_textCtrlStabTolerance; }
     wxStaticText* GetStaticTextTStabMaxIterations() { return m_staticTextTStabMaxIterations; }
@@ -223,14 +228,18 @@ public:
     wxNotebook* GetNotebook() { return m_notebook; }
     wxButton* GetButtonOK() { return m_buttonOK; }
     wxButton* GetButtonCancel() { return m_buttonCancel; }
-    SimulationsSettingsFormBase(wxWindow* parent, wxWindowID id = wxID_ANY, const wxString& title = _("Simulation settings"), const wxPoint& pos = wxDefaultPosition, const wxSize& size = wxSize(-1,-1), long style = wxDEFAULT_DIALOG_STYLE);
+    SimulationsSettingsFormBase(wxWindow* parent,
+                                wxWindowID id = wxID_ANY,
+                                const wxString& title = _("Simulation settings"),
+                                const wxPoint& pos = wxDefaultPosition,
+                                const wxSize& size = wxSize(-1, -1),
+                                long style = wxDEFAULT_DIALOG_STYLE);
     virtual ~SimulationsSettingsFormBase();
 };
 
-
 class AboutFormBase : public wxDialog
 {
-protected:
+   protected:
     wxNotebook* m_notebook;
     wxPanel* m_panelLogo;
     wxStaticBitmap* m_staticBitmapLogo;
@@ -244,10 +253,10 @@ protected:
     wxHyperlinkCtrl* m_hyperLinkPSP;
     wxButton* m_buttonOK;
 
-protected:
+   protected:
     virtual void OnOKButtonClick(wxCommandEvent& event) { event.Skip(); }
 
-public:
+   public:
     wxStaticBitmap* GetStaticBitmapLogo() { return m_staticBitmapLogo; }
     wxPanel* GetPanelLogo() { return m_panelLogo; }
     wxGrid* GetGridCredits() { return m_gridCredits; }
@@ -260,14 +269,18 @@ public:
     wxStaticText* GetStaticTextHome() { return m_staticTextHome; }
     wxHyperlinkCtrl* GetHyperLinkPSP() { return m_hyperLinkPSP; }
     wxButton* GetButtonOK() { return m_buttonOK; }
-    AboutFormBase(wxWindow* parent, wxWindowID id = wxID_ANY, const wxString& title = _("About PSP-UFU"), const wxPoint& pos = wxDefaultPosition, const wxSize& size = wxSize(-1,-1), long style = wxDEFAULT_DIALOG_STYLE);
+    AboutFormBase(wxWindow* parent,
+                  wxWindowID id = wxID_ANY,
+                  const wxString& title = _("About PSP-UFU"),
+                  const wxPoint& pos = wxDefaultPosition,
+                  const wxSize& size = wxSize(-1, -1),
+                  long style = wxDEFAULT_DIALOG_STYLE);
     virtual ~AboutFormBase();
 };
 
-
 class ImportFormBase : public wxDialog
 {
-protected:
+   protected:
     wxNotebook* m_notebook;
     wxPanel* m_panelCEPEL;
     wxStaticText* m_staticTextBasePWFFile;
@@ -286,11 +299,11 @@ protected:
     wxButton* m_buttonOK;
     wxButton* m_buttonCancel;
 
-protected:
+   protected:
     virtual void OnButtonOKClick(wxCommandEvent& event) { event.Skip(); }
     virtual void OnButtonCancelClick(wxCommandEvent& event) { event.Skip(); }
 
-public:
+   public:
     wxStaticText* GetStaticTextBasePWFFile() { return m_staticTextBasePWFFile; }
     wxFilePickerCtrl* GetFilePickerANAREDEPWF() { return m_filePickerANAREDEPWF; }
     wxStaticText* GetStaticTextBaseLSTFile() { return m_staticTextBaseLSTFile; }
@@ -308,7 +321,12 @@ public:
     wxNotebook* GetNotebook() { return m_notebook; }
     wxButton* GetButtonOK() { return m_buttonOK; }
     wxButton* GetButtonCancel() { return m_buttonCancel; }
-    ImportFormBase(wxWindow* parent, wxWindowID id = wxID_ANY, const wxString& title = _("Import files"), const wxPoint& pos = wxDefaultPosition, const wxSize& size = wxSize(-1,-1), long style = wxDEFAULT_DIALOG_STYLE);
+    ImportFormBase(wxWindow* parent,
+                   wxWindowID id = wxID_ANY,
+                   const wxString& title = _("Import files"),
+                   const wxPoint& pos = wxDefaultPosition,
+                   const wxSize& size = wxSize(-1, -1),
+                   long style = wxDEFAULT_DIALOG_STYLE);
     virtual ~ImportFormBase();
 };
 
diff --git a/Project/SimulationsSettingsForm.cpp b/Project/SimulationsSettingsForm.cpp
index b7878d5..2947638 100644
--- a/Project/SimulationsSettingsForm.cpp
+++ b/Project/SimulationsSettingsForm.cpp
@@ -41,6 +41,7 @@ SimulationsSettingsForm::SimulationsSettingsForm(wxWindow* parent, PropertiesDat
     }
     m_checkBoxFaultAfterPF->SetValue(data.faultAfterPowerFlow);
     m_checkBoxSCPowerAfterPF->SetValue(data.scPowerAfterPowerFlow);
+    m_checkBoxTHDAfterPF->SetValue(data.harmDistortionAfterPowerFlow);
     switch(data.powerFlowMethod) {
         case GAUSS_SEIDEL: {
             m_choicePFMethod->SetSelection(0);
@@ -107,6 +108,7 @@ bool SimulationsSettingsForm::ValidateData()
     }
     data.faultAfterPowerFlow = m_checkBoxFaultAfterPF->GetValue();
     data.scPowerAfterPowerFlow = m_checkBoxSCPowerAfterPF->GetValue();
+    data.harmDistortionAfterPowerFlow = m_checkBoxTHDAfterPF->GetValue();
     switch(m_choicePFMethod->GetSelection()) {
         case 0: {
             data.powerFlowMethod = GAUSS_SEIDEL;
diff --git a/Project/SyncGenerator.cpp b/Project/SyncGenerator.cpp
index c988a7e..78082d2 100644
--- a/Project/SyncGenerator.cpp
+++ b/Project/SyncGenerator.cpp
@@ -223,7 +223,7 @@ wxString SyncGenerator::GetTipText() const
     return tipText;
 }
 
-bool SyncGenerator::GetPlotData(ElementPlotData& plotData)
+bool SyncGenerator::GetPlotData(ElementPlotData& plotData, PlotStudy study)
 {
     if(!m_electricalData.plotSyncMachine) return false;
     plotData.SetName(m_electricalData.name);
diff --git a/Project/SyncGenerator.h b/Project/SyncGenerator.h
index 70c4142..1a25a0e 100644
--- a/Project/SyncGenerator.h
+++ b/Project/SyncGenerator.h
@@ -156,7 +156,7 @@ class SyncGenerator : public Machines
     virtual void SetElectricalData(SyncGeneratorElectricalData electricalData) { m_electricalData = electricalData; }
     virtual void SetNominalVoltage(std::vector<double> nominalVoltage, std::vector<ElectricalUnit> nominalVoltageUnit);
     virtual void SavePlotData();
-    virtual bool GetPlotData(ElementPlotData& plotData);
+    virtual bool GetPlotData(ElementPlotData& plotData, PlotStudy study = STABILITY);
 
     virtual rapidxml::xml_node<>* SaveElement(rapidxml::xml_document<>& doc, rapidxml::xml_node<>* elementListNode);
     virtual bool OpenElement(rapidxml::xml_node<>* elementNode, std::vector<Element*> parentList);
diff --git a/Project/Text.cpp b/Project/Text.cpp
index 0697ac5..f73b425 100644
--- a/Project/Text.cpp
+++ b/Project/Text.cpp
@@ -270,6 +270,9 @@ void Text::UpdateText(double systemPowerBase)
                                 break;
                         }
                     } break;
+                    case DATA_PQ_THD: {
+                        SetText("THD = " + wxString::FromDouble(data.thd, m_decimalPlaces) + "\%");
+                    } break;
                     default:
                         break;
                 }
@@ -913,6 +916,19 @@ void Text::UpdateText(double systemPowerBase)
                 }
             }
         } break;
+        case TYPE_HARMCURRENT: {
+            HarmCurrent* harmCurrent = static_cast<HarmCurrent*>(m_element);
+            if(harmCurrent) {
+                auto data = harmCurrent->GetElectricalData();
+                switch(m_dataType) {
+                    case DATA_NAME: {
+                        SetText(data.name);
+                    } break;
+                    default:
+                        break;
+                }
+            }
+        } break;
     }
 }
 
diff --git a/Project/Text.h b/Project/Text.h
index 56fc821..19e3876 100644
--- a/Project/Text.h
+++ b/Project/Text.h
@@ -64,7 +64,8 @@ enum DataType {
     DATA_PF_ACTIVE,
     DATA_PF_REACTIVE,
     DATA_PF_LOSSES,
-    DATA_PF_CURRENT
+    DATA_PF_CURRENT,
+    DATA_PQ_THD
 };
 
 /**
diff --git a/Project/TextForm.cpp b/Project/TextForm.cpp
index 993593c..30497fd 100644
--- a/Project/TextForm.cpp
+++ b/Project/TextForm.cpp
@@ -131,6 +131,9 @@ void TextForm::OnTypeChoiceSelected(wxCommandEvent& event)
                 case 5: {
                     m_text->SetDataType(DATA_SC_POWER);
                 } break;
+                case 6: {
+                    m_text->SetDataType(DATA_PQ_THD);
+                } break;
             }
         } break;
         case TYPE_SYNC_GENERATOR: {
@@ -203,7 +206,7 @@ void TextForm::OnTypeChoiceSelected(wxCommandEvent& event)
     }
     DataTypeChoice();
 
-    if(m_text->GetDataType() == DATA_NAME) Preview();
+    if(m_text->GetDataType() == DATA_NAME || m_text->GetDataType() == DATA_PQ_THD) Preview();
 }
 
 bool TextForm::LoadChoices()
@@ -305,6 +308,9 @@ bool TextForm::LoadChoices()
                             break;
                     }
                 } break;
+                case DATA_PQ_THD: {
+                    m_choiceTextType->SetSelection(6);
+                } break;
                 default:
                     break;
             }
@@ -875,6 +881,7 @@ void TextForm::ElementNumberChoice()
             arrayString.Add(_("Fault current"));
             arrayString.Add(_("Fault voltage"));
             arrayString.Add(_("Short-circuit power"));
+            arrayString.Add(_("Voltage THD"));
         } break;
         case TYPE_SYNC_GENERATOR: {
             SyncGenerator* syncGenerator = m_allElements.GetSyncGeneratorList()[index];
@@ -966,7 +973,8 @@ void TextForm::DataTypeChoice()
 
     wxArrayString arrayString;
     switch(m_text->GetDataType()) {
-        case DATA_NAME: {
+        case DATA_NAME:
+        case DATA_PQ_THD: {
             m_choiceTextUnit->Enable(false);
             return;
         } break;
@@ -1191,7 +1199,9 @@ bool TextForm::ValidateData()
     if(m_choiceElement->GetSelection() == -1) return false;
     if(m_choiceName->GetSelection() == -1) return false;
     if(m_choiceTextType->GetSelection() == -1) return false;
-    if(m_text->GetDataType() != DATA_NAME && m_choiceTextUnit->GetSelection() == -1) return false;
+    if(m_text->GetDataType() != DATA_NAME && m_text->GetDataType() != DATA_PQ_THD &&
+       m_choiceTextUnit->GetSelection() == -1)
+        return false;
     if(m_text->GetElementType() == TYPE_LINE || m_text->GetElementType() == TYPE_TRANSFORMER) {
         if(m_text->GetDataType() != DATA_PF_LOSSES && m_text->GetDataType() != DATA_NAME) {
             if(m_choiceTextFromBus->GetSelection() == -1) return false;
diff --git a/Project/Workspace.cpp b/Project/Workspace.cpp
index a17faae..6b8d197 100644
--- a/Project/Workspace.cpp
+++ b/Project/Workspace.cpp
@@ -1491,8 +1491,8 @@ void Workspace::OnMiddleDoubleClick(wxMouseEvent& event)
 
 bool Workspace::RunStaticStudies()
 {
-    bool pfStatus, faultStatus, scStatus;
-    pfStatus = faultStatus = scStatus = false;
+    bool pfStatus, faultStatus, scStatus, harmStatus;
+    pfStatus = faultStatus = scStatus = harmStatus = false;
 
     pfStatus = RunPowerFlow();
 
@@ -1507,8 +1507,14 @@ bool Workspace::RunStaticStudies()
     } else {
         scStatus = true;
     }
+    
+    if(m_properties->GetSimulationPropertiesData().harmDistortionAfterPowerFlow) {
+        if(pfStatus) harmStatus = RunHarmonicDistortion();
+    } else {
+        harmStatus = true;
+    }
 
-    if(pfStatus && faultStatus && scStatus) return true;
+    if(pfStatus && faultStatus && scStatus && harmStatus) return true;
 
     return false;
 }
@@ -1523,5 +1529,43 @@ bool Workspace::RunHarmonicDistortion()
         basePower *= 1e3;
     if(!RunPowerFlow()) return false;
     PowerQuality pq(GetElementList());
-    return pq.CalculateDistortions(basePower);
+    bool result =  pq.CalculateDistortions(basePower);
+    
+    UpdateTextElements();
+    Redraw();
+    
+    return result;
+}
+
+bool Workspace::RunFrequencyResponse()
+{
+    auto simProp = m_properties->GetSimulationPropertiesData();
+    double basePower = simProp.basePower;
+    if(simProp.basePowerUnit == UNIT_MVA)
+        basePower *= 1e6;
+    else if(simProp.basePowerUnit == UNIT_kVA)
+        basePower *= 1e3;
+    PowerQuality pq(GetElementList());
+    bool result =  pq.CalculateFrequencyResponse(simProp.stabilityFrequency, 0.0, 1500.0, 1.0, basePower);
+    
+    wxMessageDialog msgDialog(
+        this,
+        wxString::Format(_("Calculations done.\nDo you wish to open the frequency response graphics?")),
+        _("Question"), wxYES_NO | wxCENTRE | wxICON_QUESTION);
+    if(msgDialog.ShowModal() == wxID_YES) {
+        std::vector<ElementPlotData> plotDataList;
+        for(auto it = m_elementList.begin(), itEnd = m_elementList.end(); it != itEnd; ++it) {
+            PowerElement* element = *it;
+            ElementPlotData plotData;
+            if(element->GetPlotData(plotData, FREQRESPONSE)) plotDataList.push_back(plotData);
+        }
+
+        ChartView* cView = new ChartView(this, plotDataList, pq.GetFrequencies());
+        cView->Show();
+    }
+    
+    UpdateTextElements();
+    Redraw();
+    
+    return result;
 }
diff --git a/Project/Workspace.h b/Project/Workspace.h
index 38c5356..afcb1b3 100644
--- a/Project/Workspace.h
+++ b/Project/Workspace.h
@@ -149,6 +149,7 @@ class Workspace : public WorkspaceBase
     bool RunStaticStudies();
     bool RunStability();
     bool RunHarmonicDistortion();
+    bool RunFrequencyResponse();
 
    protected:
     virtual void OnMiddleDoubleClick(wxMouseEvent& event);