SP_Ph1_Transformer.cpp

Go to the documentation of this file.

/* Copyright 2017-2021 Institute for Automation of Complex Power Systems,
 *                     EONERC, RWTH Aachen University
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 *********************************************************************************/
 
#include <dpsim-models/MathUtils.h>
#include <dpsim-models/SP/SP_Ph1_Transformer.h>
 
using namespace CPS;
 
// #### General ####
SP::Ph1::Transformer::Transformer(String uid, String name,
                                  Logger::Level logLevel,
                                  Bool withResistiveLosses)
    : Base::Ph1::Transformer(mAttributes),
      CompositePowerComp<Complex>(uid, name, true, true, logLevel),
      mBaseVoltage(mAttributes->create<Real>("base_Voltage")),
      mCurrent(mAttributes->create<MatrixComp>("current_vector")),
      mActivePowerBranch(mAttributes->create<Matrix>("p_branch_vector")),
      mReactivePowerBranch(mAttributes->create<Matrix>("q_branch_vector")),
      mActivePowerInjection(mAttributes->create<Real>("p_inj")),
      mReactivePowerInjection(mAttributes->create<Real>("q_inj")) {
  if (withResistiveLosses)
    setVirtualNodeNumber(3);
  else
    setVirtualNodeNumber(2);
 
  SPDLOG_LOGGER_INFO(mSLog, "Create {} {}", this->type(), name);
  **mIntfVoltage = MatrixComp::Zero(1, 1);
  **mIntfCurrent = MatrixComp::Zero(1, 1);
  setTerminalNumber(2);
 
  **mCurrent = MatrixComp::Zero(2, 1);
  **mActivePowerBranch = Matrix::Zero(2, 1);
  **mReactivePowerBranch = Matrix::Zero(2, 1);
}
 
void SP::Ph1::Transformer::setParameters(Real nomVoltageEnd1,
                                         Real nomVoltageEnd2, Real ratioAbs,
                                         Real ratioPhase, Real resistance,
                                         Real inductance) {
 
  // Note: to be consistent impedance values must be referred to high voltage side (and base voltage set to higher voltage)
  Base::Ph1::Transformer::setParameters(nomVoltageEnd1, nomVoltageEnd2,
                                        ratioAbs, ratioPhase, resistance,
                                        inductance);
 
  SPDLOG_LOGGER_INFO(
      mSLog, "Nominal Voltage End 1={} [V] Nominal Voltage End 2={} [V]",
      mNominalVoltageEnd1, mNominalVoltageEnd2);
  SPDLOG_LOGGER_INFO(
      mSLog, "Resistance={} [Ohm] Inductance={} [H] (referred to primary side)",
      **mResistance, **mInductance);
  SPDLOG_LOGGER_INFO(mSLog, "Tap Ratio={} [/] Phase Shift={} [deg]",
                     std::abs(**mRatio), std::arg(**mRatio));
  SPDLOG_LOGGER_INFO(mSLog, "Rated Power ={} [VA]", **mRatedPower);
 
  mRatioAbs = std::abs(**mRatio);
  mRatioPhase = std::arg(**mRatio);
 
  mParametersSet = true;
}
 
void SP::Ph1::Transformer::setParameters(Real nomVoltageEnd1,
                                         Real nomVoltageEnd2, Real ratedPower,
                                         Real ratioAbs, Real ratioPhase,
                                         Real resistance, Real inductance) {
 
  // Rated power is the nameplate apparent-power magnitude |S|, so it cannot be
  // negative (a negative value is a caller error, not the unset default of 0).
  if (ratedPower < 0) {
    SPDLOG_LOGGER_ERROR(mSLog, "Rated power {} [VA] is negative; must be >= 0",
                        ratedPower);
    throw InvalidArgumentException();
  }
 
  **mRatedPower = ratedPower;
  SPDLOG_LOGGER_INFO(mSLog, "Rated Power ={} [VA]", **mRatedPower);
 
  SP::Ph1::Transformer::setParameters(nomVoltageEnd1, nomVoltageEnd2, ratioAbs,
                                      ratioPhase, resistance, inductance);
}

SimPowerComp<Complex>::Ptr SP::Ph1::Transformer::clone(String name) {
  auto copy = Transformer::make(name, mLogLevel);
  copy->setParameters(mNominalVoltageEnd1, mNominalVoltageEnd2, **mRatedPower,
                      std::abs(**mRatio), std::arg(**mRatio), **mResistance,
                      **mInductance);
  return copy;
}
 
void SP::Ph1::Transformer::createSubComponents() {
  if (mSubCompCreated)
    return;
  mSubCompCreated = true;
 
  // Switch terminals so that terminal 0 is always the higher-voltage side.
  if (Math::abs(**mRatio) < 1.) {
    **mRatio = 1. / **mRatio;
    mRatioAbs = std::abs(**mRatio);
    mRatioPhase = std::arg(**mRatio);
    std::shared_ptr<SimTerminal<Complex>> tmp = mTerminals[0];
    mTerminals[0] = mTerminals[1];
    mTerminals[1] = tmp;
    Real tmpVolt = mNominalVoltageEnd1;
    mNominalVoltageEnd1 = mNominalVoltageEnd2;
    mNominalVoltageEnd2 = tmpVolt;
    SPDLOG_LOGGER_INFO(mSLog, "Switching terminals to have first terminal at "
                              "higher voltage side. Updated parameters: ");
    SPDLOG_LOGGER_INFO(
        mSLog, "Nominal Voltage End 1 = {} [V] Nominal Voltage End 2 = {} [V]",
        mNominalVoltageEnd1, mNominalVoltageEnd2);
    SPDLOG_LOGGER_INFO(mSLog, "Tap Ratio = {} [ ] Phase Shift = {} [deg]",
                       mRatioAbs, mRatioPhase);
    // Refresh index cache after terminal swap so pfApplyAdmittanceMatrixStamp uses the correct order.
    updateMatrixNodeIndices();
  }
 
  // Create series sub components
  mSubInductor = std::make_shared<SP::Ph1::Inductor>(
      **mUID + "_ind", **mName + "_ind", Logger::Level::off);
  mSubInductor->setParameters(**mInductance);
  addMNASubComponent(mSubInductor, MNA_SUBCOMP_TASK_ORDER::TASK_BEFORE_PARENT,
                     MNA_SUBCOMP_TASK_ORDER::TASK_BEFORE_PARENT, true);
 
  if (mNumVirtualNodes == 3) {
    mSubResistor = std::make_shared<SP::Ph1::Resistor>(
        **mUID + "_res", **mName + "_res", Logger::Level::off);
    mSubResistor->setParameters(**mResistance);
    mSubResistor->connect({node(0), mVirtualNodes[2]});
    mSubInductor->connect({mVirtualNodes[2], mVirtualNodes[0]});
    addMNASubComponent(mSubResistor, MNA_SUBCOMP_TASK_ORDER::TASK_BEFORE_PARENT,
                       MNA_SUBCOMP_TASK_ORDER::TASK_BEFORE_PARENT, true);
  } else {
    mSubInductor->connect({node(0), mVirtualNodes[0]});
  }
 
  // Snubber sub-components created here; their omega/power-dependent values are set in
  // initializeParentFromNodesAndTerminals(). Snubbers are sized off the rated power, so
  // without a valid rating they collapse to infinite resistance and zero capacitance
  // (NaN admittance) that poisons the system matrix; skip creating them in that case.
  bool snubbersEnabled =
      (mBehaviour == TopologicalPowerComp::Behaviour::Initialization ||
       mBehaviour == TopologicalPowerComp::Behaviour::MNASimulation);
  if (snubbersEnabled && **mRatedPower <= 0) {
    SPDLOG_LOGGER_WARN(mSLog,
                       "Rated power is {} [VA]; snubbers disabled for this "
                       "transformer (cannot be sized off non-positive power).",
                       **mRatedPower);
    snubbersEnabled = false;
  }
  if (snubbersEnabled) {
 
    mSubSnubResistor1 =
        std::make_shared<SP::Ph1::Resistor>(**mName + "_snub_res1", mLogLevel);
    mSubSnubResistor1->connect({node(0), SP::SimNode::GND});
    addMNASubComponent(mSubSnubResistor1,
                       MNA_SUBCOMP_TASK_ORDER::TASK_BEFORE_PARENT,
                       MNA_SUBCOMP_TASK_ORDER::TASK_BEFORE_PARENT, true);
 
    mSubSnubResistor2 =
        std::make_shared<SP::Ph1::Resistor>(**mName + "_snub_res2", mLogLevel);
    mSubSnubResistor2->connect({node(1), SP::SimNode::GND});
    addMNASubComponent(mSubSnubResistor2,
                       MNA_SUBCOMP_TASK_ORDER::TASK_BEFORE_PARENT,
                       MNA_SUBCOMP_TASK_ORDER::TASK_BEFORE_PARENT, true);
 
    mSubSnubCapacitor2 =
        std::make_shared<SP::Ph1::Capacitor>(**mName + "_snub_cap2", mLogLevel);
    mSubSnubCapacitor2->connect({node(1), SP::SimNode::GND});
    addMNASubComponent(mSubSnubCapacitor2,
                       MNA_SUBCOMP_TASK_ORDER::TASK_BEFORE_PARENT,
                       MNA_SUBCOMP_TASK_ORDER::TASK_BEFORE_PARENT, true);
  }
}
 
void SP::Ph1::Transformer::initializeParentFromNodesAndTerminals(
    Real frequency) {
  mNominalOmega = 2. * PI * frequency;
  mReactance = mNominalOmega * **mInductance;
  SPDLOG_LOGGER_INFO(mSLog, "Reactance={} [Ohm] (referred to primary side)",
                     mReactance);
 
  if (mSubSnubResistor1) {
    Real pSnub = P_SNUB_TRANSFORMER * **mRatedPower;
    Real qSnub = Q_SNUB_TRANSFORMER * **mRatedPower;
 
    // A snubber conductance is added on the higher voltage side
    mSnubberResistance1 = std::pow(std::abs(mNominalVoltageEnd1), 2) / pSnub;
    mSubSnubResistor1->setParameters(mSnubberResistance1);
    SPDLOG_LOGGER_INFO(
        mSLog,
        "Snubber Resistance 1 (connected to higher voltage side {}) = {} [Ohm]",
        node(0)->name(), Logger::realToString(mSnubberResistance1));
    mSubSnubResistor1->setBaseVoltage(mNominalVoltageEnd1);
 
    // A snubber conductance is added on the lower voltage side
    mSnubberResistance2 = std::pow(std::abs(mNominalVoltageEnd2), 2) / pSnub;
    mSubSnubResistor2->setParameters(mSnubberResistance2);
    SPDLOG_LOGGER_INFO(
        mSLog,
        "Snubber Resistance 2 (connected to lower voltage side {}) = {} [Ohm]",
        node(1)->name(), Logger::realToString(mSnubberResistance2));
    mSubSnubResistor2->setBaseVoltage(mNominalVoltageEnd2);
 
    // // A snubber capacitance is added to higher voltage side (not used as capacitor at high voltage side made it worse)
    // mSnubberCapacitance1 = qSnub / std::pow(std::abs(mNominalVoltageEnd1),2) / mNominalOmega;
    // mSubSnubCapacitor1 = std::make_shared<SP::Ph1::Capacitor>(**mName + "_snub_cap1", mLogLevel);
    // mSubSnubCapacitor1->setParameters(mSnubberCapacitance1);
    // mSubSnubCapacitor1->connect({ node(0), SP::SimNode::GND });
    // SPDLOG_LOGGER_INFO(mSLog, "Snubber Capacitance 1 (connected to higher voltage side {}) = \n{} [F] \n ", node(0)->name(), Logger::realToString(mSnubberCapacitance1));
    // mSubSnubCapacitor1->setBaseVoltage(mNominalVoltageEnd1);
    // mSubComponents.push_back(mSubSnubCapacitor1);
 
    // A snubber capacitance is added to lower voltage side
    mSnubberCapacitance2 =
        qSnub / std::pow(std::abs(mNominalVoltageEnd2), 2) / mNominalOmega;
    mSubSnubCapacitor2->setParameters(mSnubberCapacitance2);
    SPDLOG_LOGGER_INFO(
        mSLog,
        "Snubber Capacitance 2 (connected to lower voltage side {}) = {} [F]",
        node(1)->name(), Logger::realToString(mSnubberCapacitance2));
    mSubSnubCapacitor2->setBaseVoltage(mNominalVoltageEnd2);
  }
 
  // Set initial voltage of virtual node in between
  mVirtualNodes[0]->setInitialVoltage(initialSingleVoltage(1) * **mRatio);
 
  // Static calculations from load flow data
  Complex impedance = {**mResistance, mReactance};
  (**mIntfVoltage)(0, 0) =
      mVirtualNodes[0]->initialSingleVoltage() - initialSingleVoltage(0);
  (**mIntfCurrent)(0, 0) = (**mIntfVoltage)(0, 0) / impedance;
 
  if (mNumVirtualNodes == 3)
    mVirtualNodes[2]->setInitialVoltage(initialSingleVoltage(0));
 
  SPDLOG_LOGGER_INFO(
      mSLog,
      "\n--- Initialization from powerflow ---"
      "\nVoltage across: {:s}"
      "\nCurrent: {:s}"
      "\nTerminal 0 voltage: {:s}"
      "\nTerminal 1 voltage: {:s}"
      "\nVirtual Node 1 voltage: {:s}"
      "\n--- Initialization from powerflow finished ---",
      Logger::phasorToString((**mIntfVoltage)(0, 0)),
      Logger::phasorToString((**mIntfCurrent)(0, 0)),
      Logger::phasorToString(initialSingleVoltage(0)),
      Logger::phasorToString(initialSingleVoltage(1)),
      Logger::phasorToString(mVirtualNodes[0]->initialSingleVoltage()));
}
 
// #### Powerflow section ####
 
Real SP::Ph1::Transformer::getNominalVoltageEnd1() const {
  return mNominalVoltageEnd1;
}
 
Real SP::Ph1::Transformer::getNominalVoltageEnd2() const {
  return mNominalVoltageEnd2;
}
 
void SP::Ph1::Transformer::setBaseVoltage(Real baseVoltage) {
  // Note: to be consistent set base voltage to higher voltage (and impedance values must be referred to high voltage side)
  // TODO: use attribute setter for setting base voltage
  **mBaseVoltage = baseVoltage;
}
 
void SP::Ph1::Transformer::calculatePerUnitParameters(Real baseApparentPower,
                                                      Real baseOmega) {
  SPDLOG_LOGGER_INFO(mSLog, "#### Calculate Per Unit Parameters for {}",
                     **mName);
  mBaseApparentPower = baseApparentPower;
  mBaseOmega = baseOmega;
  SPDLOG_LOGGER_INFO(mSLog, "Base Power={} [VA]  Base Omega={} [1/s]",
                     baseApparentPower, baseOmega);
 
  mBaseImpedance = **mBaseVoltage * **mBaseVoltage / mBaseApparentPower;
  mBaseAdmittance = 1.0 / mBaseImpedance;
  mBaseCurrent = baseApparentPower /
                 (**mBaseVoltage *
                  sqrt(3)); // I_base=(S_threephase/3)/(V_line_to_line/sqrt(3))
  SPDLOG_LOGGER_INFO(mSLog, "Base Voltage={} [V]  Base Impedance={} [Ohm]",
                     **mBaseVoltage, mBaseImpedance);
 
  mResistancePerUnit = **mResistance / mBaseImpedance;
  mReactancePerUnit = mReactance / mBaseImpedance;
  SPDLOG_LOGGER_INFO(mSLog, "Resistance={} [pu]  Reactance={} [pu]",
                     mResistancePerUnit, mReactancePerUnit);
 
  mBaseInductance = mBaseImpedance / mBaseOmega;
  mInductancePerUnit = **mInductance / mBaseInductance;
  // omega per unit=1, hence 1.0*mInductancePerUnit.
  mLeakagePerUnit = Complex(mResistancePerUnit, 1. * mInductancePerUnit);
  SPDLOG_LOGGER_INFO(mSLog, "Leakage Impedance={} [pu] ", mLeakagePerUnit);
 
  mRatioAbsPerUnit = mRatioAbs / mNominalVoltageEnd1 * mNominalVoltageEnd2;
  SPDLOG_LOGGER_INFO(mSLog, "Tap Ratio={} [pu]", mRatioAbsPerUnit);
 
  // Calculate per unit parameters of subcomps
  if (mSubSnubResistor1)
    mSubSnubResistor1->calculatePerUnitParameters(mBaseApparentPower);
  if (mSubSnubResistor2)
    mSubSnubResistor2->calculatePerUnitParameters(mBaseApparentPower);
  if (mSubSnubCapacitor1)
    mSubSnubCapacitor1->calculatePerUnitParameters(mBaseApparentPower);
  if (mSubSnubCapacitor2)
    mSubSnubCapacitor2->calculatePerUnitParameters(mBaseApparentPower);
}
 
void SP::Ph1::Transformer::pfApplyAdmittanceMatrixStamp(
    SparseMatrixCompRow &Y) {
  // calculate matrix stamp
  mY_element = MatrixComp(2, 2);
  Complex y = Complex(1, 0) / mLeakagePerUnit;
 
  mY_element(0, 0) = y;
  mY_element(0, 1) = -y * mRatioAbsPerUnit;
  mY_element(1, 0) = -y * mRatioAbsPerUnit;
  mY_element(1, 1) = y * std::pow(mRatioAbsPerUnit, 2);
 
  //check for inf or nan
  for (int i = 0; i < 2; i++)
    for (int j = 0; j < 2; j++)
      if (!Math::isFinite(mY_element.coeff(i, j))) {
        SPDLOG_LOGGER_ERROR(
            mSLog,
            "Transformer {}: non-finite per-unit admittance {} "
            "in element Y({},{}) (leakage {}, tap {})",
            this->name(), Logger::complexToString(mY_element.coeff(i, j)), i, j,
            Logger::complexToString(mLeakage), mRatioAbsPerUnit);
        throw InvalidArgumentException();
      }
 
  //set the circuit matrix values
  Y.coeffRef(this->matrixNodeIndex(0), this->matrixNodeIndex(0)) +=
      mY_element.coeff(0, 0);
  Y.coeffRef(this->matrixNodeIndex(0), this->matrixNodeIndex(1)) +=
      mY_element.coeff(0, 1);
  Y.coeffRef(this->matrixNodeIndex(1), this->matrixNodeIndex(1)) +=
      mY_element.coeff(1, 1);
  Y.coeffRef(this->matrixNodeIndex(1), this->matrixNodeIndex(0)) +=
      mY_element.coeff(1, 0);
 
  SPDLOG_LOGGER_INFO(mSLog, "#### Y matrix stamping: {}", mY_element);
 
  if (mSubSnubResistor1)
    mSubSnubResistor1->pfApplyAdmittanceMatrixStamp(Y);
  if (mSubSnubResistor2)
    mSubSnubResistor2->pfApplyAdmittanceMatrixStamp(Y);
  if (mSubSnubCapacitor1)
    mSubSnubCapacitor1->pfApplyAdmittanceMatrixStamp(Y);
  if (mSubSnubCapacitor2)
    mSubSnubCapacitor2->pfApplyAdmittanceMatrixStamp(Y);
}
 
void SP::Ph1::Transformer::updateBranchFlow(VectorComp &current,
                                            VectorComp &powerflow) {
  **mCurrent = current * mBaseCurrent;
  **mActivePowerBranch = powerflow.real() * mBaseApparentPower;
  **mReactivePowerBranch = powerflow.imag() * mBaseApparentPower;
}
 
void SP::Ph1::Transformer::storeNodalInjection(Complex powerInjection) {
  **mActivePowerInjection = std::real(powerInjection) * mBaseApparentPower;
  **mReactivePowerInjection = std::imag(powerInjection) * mBaseApparentPower;
}
 
MatrixComp SP::Ph1::Transformer::Y_element() { return mY_element; }
 
// #### MNA Section ####
 
void SP::Ph1::Transformer::mnaParentInitialize(
    Real omega, Real timeStep, Attribute<Matrix>::Ptr leftVector) {
  SPDLOG_LOGGER_INFO(
      mSLog,
      "\nTerminal 0 connected to {:s} = sim node {:d}"
      "\nTerminal 1 connected to {:s} = sim node {:d}",
      mTerminals[0]->node()->name(), mTerminals[0]->node()->matrixNodeIndex(),
      mTerminals[1]->node()->name(), mTerminals[1]->node()->matrixNodeIndex());
}
 
void SP::Ph1::Transformer::mnaCompApplySystemMatrixStamp(
    SparseMatrixRow &systemMatrix) {
  // Ideal transformer equations
  if (terminalNotGrounded(0)) {
    Math::setMatrixElement(systemMatrix, mVirtualNodes[0]->matrixNodeIndex(),
                           mVirtualNodes[1]->matrixNodeIndex(),
                           Complex(-1.0, 0));
    Math::setMatrixElement(systemMatrix, mVirtualNodes[1]->matrixNodeIndex(),
                           mVirtualNodes[0]->matrixNodeIndex(),
                           Complex(1.0, 0));
  }
  if (terminalNotGrounded(1)) {
    Math::setMatrixElement(systemMatrix, matrixNodeIndex(1),
                           mVirtualNodes[1]->matrixNodeIndex(), **mRatio);
    Math::setMatrixElement(systemMatrix, mVirtualNodes[1]->matrixNodeIndex(),
                           matrixNodeIndex(1), -**mRatio);
  }
 
  // Add subcomps to system matrix
  for (auto subcomp : mSubComponents)
    if (auto mnasubcomp = std::dynamic_pointer_cast<MNAInterface>(subcomp))
      mnasubcomp->mnaApplySystemMatrixStamp(systemMatrix);
 
  if (terminalNotGrounded(0)) {
    SPDLOG_LOGGER_INFO(mSLog, "Add {:s} to system at ({:d},{:d})",
                       Logger::complexToString(Complex(-1.0, 0)),
                       mVirtualNodes[0]->matrixNodeIndex(),
                       mVirtualNodes[1]->matrixNodeIndex());
    SPDLOG_LOGGER_INFO(mSLog, "Add {:s} to system at ({:d},{:d})",
                       Logger::complexToString(Complex(1.0, 0)),
                       mVirtualNodes[1]->matrixNodeIndex(),
                       mVirtualNodes[0]->matrixNodeIndex());
  }
  if (terminalNotGrounded(1)) {
    SPDLOG_LOGGER_INFO(mSLog, "Add {:s} to system at ({:d},{:d})",
                       Logger::complexToString(**mRatio), matrixNodeIndex(1),
                       mVirtualNodes[1]->matrixNodeIndex());
    SPDLOG_LOGGER_INFO(mSLog, "Add {:s} to system at ({:d},{:d})",
                       Logger::complexToString(-**mRatio),
                       mVirtualNodes[1]->matrixNodeIndex(), matrixNodeIndex(1));
  }
}
 
void SP::Ph1::Transformer::mnaParentAddPreStepDependencies(
    AttributeBase::List &prevStepDependencies,
    AttributeBase::List &attributeDependencies,
    AttributeBase::List &modifiedAttributes) {
  prevStepDependencies.push_back(mIntfCurrent);
  prevStepDependencies.push_back(mIntfVoltage);
  modifiedAttributes.push_back(mRightVector);
}
 
void SP::Ph1::Transformer::mnaParentPreStep(Real time, Int timeStepCount) {
  mnaCompApplyRightSideVectorStamp(**mRightVector);
}
 
void SP::Ph1::Transformer::mnaParentAddPostStepDependencies(
    AttributeBase::List &prevStepDependencies,
    AttributeBase::List &attributeDependencies,
    AttributeBase::List &modifiedAttributes,
    Attribute<Matrix>::Ptr &leftVector) {
  attributeDependencies.push_back(leftVector);
  modifiedAttributes.push_back(mIntfVoltage);
  modifiedAttributes.push_back(mIntfCurrent);
}
 
void SP::Ph1::Transformer::mnaParentPostStep(
    Real time, Int timeStepCount, Attribute<Matrix>::Ptr &leftVector) {
  this->mnaUpdateVoltage(**leftVector);
  this->mnaUpdateCurrent(**leftVector);
}
 
void SP::Ph1::Transformer::mnaCompUpdateCurrent(const Matrix &leftVector) {
  (**mIntfCurrent)(0, 0) = mSubInductor->intfCurrent()(0, 0);
  SPDLOG_LOGGER_DEBUG(mSLog, "Current {:s}",
                      Logger::phasorToString((**mIntfCurrent)(0, 0)));
}
 
void SP::Ph1::Transformer::mnaCompUpdateVoltage(const Matrix &leftVector) {
  // v1 - v0
  (**mIntfVoltage)(0, 0) = 0;
  (**mIntfVoltage)(0, 0) =
      Math::complexFromVectorElement(leftVector, matrixNodeIndex(1));
  (**mIntfVoltage)(0, 0) = (**mIntfVoltage)(0, 0) -
                           Math::complexFromVectorElement(
                               leftVector, mVirtualNodes[0]->matrixNodeIndex());
  SPDLOG_LOGGER_DEBUG(mSLog, "Voltage {:s}",
                      Logger::phasorToString((**mIntfVoltage)(0, 0)));
}