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added branch PQ calculation for transformer and modified the code a bit
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@yliu250
yliu250 committed Sep 4, 2024
1 parent bc9db09 commit a7ab84d
Showing 1 changed file with 88 additions and 55 deletions.
143 changes: 88 additions & 55 deletions src/applications/modules/dynamic_simulation_full_y/dsf_components.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3593,25 +3593,23 @@ void gridpack::dynamic_simulation::DSFullBranch::load(
void gridpack::dynamic_simulation::DSFullBranch::evaluateBranchFlow()
{
int i;
double dbranchR, dbranchX;
double dbranchB;
double dbranchPhaseShift, dbranchTapRatio;
double pi = 4.0*atan(1.0);

gridpack::dynamic_simulation::DSFullBus *bus1 =
dynamic_cast<gridpack::dynamic_simulation::DSFullBus*>(getBus1().get());
gridpack::dynamic_simulation::DSFullBus *bus2 =
dynamic_cast<gridpack::dynamic_simulation::DSFullBus*>(getBus2().get());

//get bus voltages
gridpack::ComplexType c_Z, c_branchcurr;
gridpack::ComplexType c_Ysh, c_frombusshuntcurr, c_tobusshuntcurr;
gridpack::ComplexType c_branchfrombuspq, c_branchtobuspq;
p_branchfrombusvolt = bus1->getComplexVoltage();
p_branchtobusvolt = bus2->getComplexVoltage();

// printf ("Branch volts bus1, %8.4f+%8.4fj, bus 2, %8.4f+%8.4fj,\n", real(p_branchfrombusvolt),
// imag(p_branchfrombusvolt), real(p_branchtobusvolt),imag(p_branchtobusvolt) );

// define branch from and to bus p + jq
gridpack::ComplexType c_branchfrombuspq, c_branchtobuspq;

if (!p_branchfrombuspq.empty()){
p_branchfrombuspq.clear();
}
Expand All @@ -3621,37 +3619,72 @@ void gridpack::dynamic_simulation::DSFullBranch::evaluateBranchFlow()
}

for ( i=0 ; i<p_elems ; i++ ) {
dbranchR = p_resistance[i];
dbranchX = p_reactance[i];
dbranchB = p_charging[i];
dbranchPhaseShift = p_phase_shift[i];
dbranchTapRatio = p_tap_ratio[i];

// printf ("Branch %d impedance, %8.4f+%8.4fj \n", i, dbranchR, dbranchX);
// printf ("Branch %d shunt susceptance, %8.4fj \n", i, dbranchB);
// printf ("Branch %d phase shift, %8.4f \n", i, dbranchPhaseShift);
// printf ("Branch %d tap ratio, %8.4f \n", i, dbranchTapRatio);

c_Z = gridpack::ComplexType(dbranchR, dbranchX);
c_Ysh = gridpack::ComplexType(0, dbranchB/2.0); // shunt susceptance at either end of a branch
c_branchcurr = (p_branchfrombusvolt - p_branchtobusvolt)/c_Z;
p_branchcurrent.push_back(c_branchcurr);
// printf ("Branch %d element current, %8.4f+%8.4fj \n", i, real(p_branchcurrent[i]),
// imag(p_branchcurrent[i]) );

c_frombusshuntcurr = c_Ysh * p_branchfrombusvolt;
c_tobusshuntcurr = c_Ysh * p_branchtobusvolt;
c_branchfrombuspq = p_branchfrombusvolt * conj(c_branchcurr + c_frombusshuntcurr);
c_branchtobuspq = p_branchtobusvolt * conj(c_branchcurr - c_tobusshuntcurr);

p_branchfrombuspq.push_back(c_branchfrombuspq); // active power P and reactive power Q at "from" bus (P_from + j Q_from)
p_branchtobuspq.push_back(c_branchtobuspq); // active power P and reactive power Q at "to" bus (P_to + j Q_to)

// printf ("Branch %d element from bus apparent power, %8.4f+%8.4fj \n", i, real(p_branchfrombuspq[i]),
// imag(p_branchfrombuspq[i]) );

// printf ("Branch %d element to bus apparent power, %8.4f+%8.4fj \n", i, real(p_branchtobuspq[i]),
// imag(p_branchtobuspq[i]) );

// printf ("Branch %d impedance, %8.4f+%8.4fj \n", i, p_resistance[i], p_reactance[i]);
// printf ("Branch %d shunt susceptance, %8.4fj \n", i, p_charging[i]);
// printf ("Branch %d phase shift, %8.4f \n", i, p_phase_shift[i]);
// printf ("Branch %d tap ratio, %8.4f \n", i, p_tap_ratio[i]);

if (p_xform[i]) {
// For transformer, we don't consider charging susceptance
// TODO: In PSS/E DataFormats.pdf, phase shift value is in degree.
// However, in getTransformer inside this script file, it seems cos and sin take degree as input. Need to confirm.

// calculate complex turn ratio, this part of code is referred to getTransformer
gridpack::ComplexType a(cos(p_phase_shift[i]),sin(p_phase_shift[i]));
gridpack::ComplexType c_xformsecvolt;
a = p_tap_ratio[i]*a;

// calculate secondary side voltage of idea transformer
c_xformsecvolt = p_branchfrombusvolt / a;

// calculate secondary side current and primary side current
gridpack::ComplexType c_xformpricur, c_xformseccur, c_xformz;
c_xformz = gridpack::ComplexType(p_resistance[i], p_reactance[i]);
c_xformseccur = (c_xformsecvolt - p_branchtobusvolt)/c_xformz;
c_xformpricur = c_xformseccur / a; // assume pri and sec currents of transformer are in the same direction

// calculate primary and secondary side complex power
c_branchfrombuspq = p_branchfrombusvolt * conj(c_xformpricur);
c_branchtobuspq = p_branchtobusvolt * conj(c_xformseccur);

// store from and to buses complex power into vectors
p_branchfrombuspq.push_back(c_branchfrombuspq); // active power P and reactive power Q at "from" bus (P_from + j Q_from)
p_branchtobuspq.push_back(c_branchtobuspq); // active power P and reactive power Q at "to" bus (P_to + j Q_to)

} else {
// For transmission line, we consider charging susceptance
gridpack::ComplexType c_Z, c_branchcurr;
gridpack::ComplexType c_Ysh, c_frombusshuntcurr, c_tobusshuntcurr;

// calculate line impedance and charging susceptance (on either end of the line)
c_Z = gridpack::ComplexType(p_resistance[i], p_reactance[i]);
c_Ysh = gridpack::ComplexType(0, p_charging[i]/2.0); // shunt susceptance at either end of a branch

// calculate line current
c_branchcurr = (p_branchfrombusvolt - p_branchtobusvolt)/c_Z;

// printf ("Branch %d element current, %8.4f+%8.4fj \n", i, real(c_branchcurr),
// imag(c_branchcurr) );

// calculate currents flowing through charging susceptance on from and to ends
c_frombusshuntcurr = c_Ysh * p_branchfrombusvolt;
c_tobusshuntcurr = c_Ysh * p_branchtobusvolt;

// calculate the p + jq at from and to buses
c_branchfrombuspq = p_branchfrombusvolt * conj(c_branchcurr + c_frombusshuntcurr);
c_branchtobuspq = p_branchtobusvolt * conj(c_branchcurr - c_tobusshuntcurr);

// store from and to buses complex power into vectors
p_branchfrombuspq.push_back(c_branchfrombuspq); // active power P and reactive power Q at "from" bus (P_from + j Q_from)
p_branchtobuspq.push_back(c_branchtobuspq); // active power P and reactive power Q at "to" bus (P_to + j Q_to)

// printf ("Branch %d element from bus apparent power, %8.4f+%8.4fj \n", i, real(p_branchfrombuspq[i]),
// imag(p_branchfrombuspq[i]) );

// printf ("Branch %d element to bus apparent power, %8.4f+%8.4fj \n", i, real(p_branchtobuspq[i]),
// imag(p_branchtobuspq[i]) );
}

}
}
Expand All @@ -3666,25 +3699,25 @@ void gridpack::dynamic_simulation::DSFullBranch::updateData(
int i;
evaluateBranchFlow();
for (i=0; i<p_elems; i++) {
if (p_xform[i]) {
} else {
double pf = real(p_branchfrombuspq[i]);
double qf = imag(p_branchfrombuspq[i]);
double pt = real(p_branchtobuspq[i]);
double qt = imag(p_branchtobuspq[i]);
if (!data->setValue(BRANCH_FROM_P_CURRENT, pf, i)) {
data->addValue(BRANCH_FROM_P_CURRENT, pf, i);
}
if (!data->setValue(BRANCH_FROM_Q_CURRENT, qf, i)) {
data->addValue(BRANCH_FROM_Q_CURRENT, qf, i);
}
if (!data->setValue(BRANCH_TO_P_CURRENT, pt, i)) {
data->addValue(BRANCH_TO_P_CURRENT, pt, i);
}
if (!data->setValue(BRANCH_TO_Q_CURRENT, qt, i)) {
data->addValue(BRANCH_TO_Q_CURRENT, qt, i);
}
// Here, it does not need to differentiate transformers or lines for storing the variables.
// Treating both transformers and lines as branches
double pf = real(p_branchfrombuspq[i]);
double qf = imag(p_branchfrombuspq[i]);
double pt = real(p_branchtobuspq[i]);
double qt = imag(p_branchtobuspq[i]);
if (!data->setValue(BRANCH_FROM_P_CURRENT, pf, i)) {
data->addValue(BRANCH_FROM_P_CURRENT, pf, i);
}
if (!data->setValue(BRANCH_FROM_Q_CURRENT, qf, i)) {
data->addValue(BRANCH_FROM_Q_CURRENT, qf, i);
}
if (!data->setValue(BRANCH_TO_P_CURRENT, pt, i)) {
data->addValue(BRANCH_TO_P_CURRENT, pt, i);
}
if (!data->setValue(BRANCH_TO_Q_CURRENT, qt, i)) {
data->addValue(BRANCH_TO_Q_CURRENT, qt, i);
}

}
}

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1 comment on commit a7ab84d

@yliu250
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@yliu250 yliu250 commented on a7ab84d Sep 4, 2024

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@bjpalmer and @abhyshr , I added the branch PQ calculation for transformers and modified the code a bit. We don't need to differentiate the transformer and line in updateData function because both are treated as a branch.

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