Exemple #1
0
void CONSTR_PAR_GEN_Q_count_branch(Constr* c, Branch* br) {
  
  // Local variables
  Bus* buses[2];
  Bus* bus;
  Gen* gen1;
  Gen* gen2;
  int* Acounter;
  int* Aconstr_index;
  char* bus_counted;
  int i;
  int j;
  
  // Constr data
  Acounter = CONSTR_get_Acounter_ptr(c);
  Aconstr_index = CONSTR_get_Aconstr_index_ptr(c);
  bus_counted = CONSTR_get_bus_counted(c);
  if (!Acounter || !Aconstr_index || !bus_counted)
    return;

  // Bus data
  buses[0] = BRANCH_get_bus_from(br);
  buses[1] = BRANCH_get_bus_to(br);

  // Buses
  for (i = 0; i < 2; i++) {
    
    bus = buses[i];
    
    if (!bus_counted[BUS_get_index(bus)]) {
      
      // Reactive power of regulating generators
      if (BUS_is_regulated_by_gen(bus)) {
	gen1 = BUS_get_reg_gen(bus);
	for (gen2 = GEN_get_reg_next(gen1); gen2 != NULL; gen2 = GEN_get_reg_next(gen2)) {
	  if (GEN_has_flags(gen1,FLAG_VARS,GEN_VAR_Q))
	    (*Acounter)++;
	  if (GEN_has_flags(gen2,FLAG_VARS,GEN_VAR_Q))
	    (*Acounter)++;
	  (*Aconstr_index)++;
	}
      }
    }

    // Update counted flag
    bus_counted[BUS_get_index(bus)] = TRUE;    
  }
}
Exemple #2
0
void HEUR_PVPQ_apply_step(Heur* h, Constr* clist, Net* net, Branch* br, int t, Vec* var_values) {

  // Local variables
  Vec* f;
  Mat* A;
  Vec* b;
  Bus* bus[2];
  Gen* gen;
  char* bus_counted;
  Heur_PVPQ_Data* data;
  char* reg_flag;
  int bus_index_t[2];
  int k;
  int i;
  Constr* pf;
  Constr* fix;
  REAL v;
  REAL v_set;
  REAL Q;
  REAL Qmax;
  REAL Qmin;
  char switch_flag;
  int j_old;
  int j_new;
  REAL b_new;
  int T;
  int num_buses;

  // Num periods
  T = BRANCH_get_num_periods(br);

  // Num buses
  num_buses = NET_get_num_buses(net);

  // Heur data
  bus_counted = HEUR_get_bus_counted(h);
  data = (Heur_PVPQ_Data*)HEUR_get_data(h);
  reg_flag = data->reg_flag;

  // Check outage
  if (BRANCH_is_on_outage(br))
    return;

  // Bus from data
  bus[0] = BRANCH_get_bus_k(br);
  bus_index_t[0] = BUS_get_index(bus[0])*T+t;

  // Bus to data
  bus[1] = BRANCH_get_bus_m(br);
  bus_index_t[1] = BUS_get_index(bus[1])*T+t;

  // Power flow constraints
  for (pf = clist; pf != NULL; pf = CONSTR_get_next(pf)) {
    if (strcmp(CONSTR_get_name(pf),"AC power balance") == 0)
      break;
  }
  if (!pf)
    return;

  // Fix constraints
  for (fix = clist; fix != NULL; fix = CONSTR_get_next(fix)) {
    if (strcmp(CONSTR_get_name(fix),"variable fixing") == 0)
      break;
  }
  if (!fix)
    return;

  // Constr data
  f = CONSTR_get_f(pf);
  A = CONSTR_get_A(fix);
  b = CONSTR_get_b(fix);

  // Buses
  for (k = 0; k < 2; k++) {

    if (!bus_counted[bus_index_t[k]] &&                   // not counted
	!BUS_is_slack(bus[k]) &&                          // not slack
	BUS_is_regulated_by_gen(bus[k]) &&                // regulated
	BUS_has_flags(bus[k],FLAG_VARS,BUS_VAR_VMAG) &&   // v mag is variable
	BUS_has_flags(bus[k],FLAG_FIXED,BUS_VAR_VMAG) &&  // v mag is fixed
	GEN_has_flags(BUS_get_reg_gen(bus[k]),FLAG_VARS,GEN_VAR_Q)) { // reg gen Q is variable

      // Voltage magnitude
      v = VEC_get(var_values,BUS_get_index_v_mag(bus[k],t));
      v_set = BUS_get_v_set(bus[k],t);

      // Regulating generator (first one in list of reg gens)
      gen = BUS_get_reg_gen(bus[k]);
      Q = VEC_get(var_values,GEN_get_index_Q(gen,t)); // per unit
      Qmax = GEN_get_Q_max(gen);                      // per unit
      Qmin = GEN_get_Q_min(gen);                      // per unit

      // Switch flag
      switch_flag = FALSE;

      // Currently regulated
      if (reg_flag[bus_index_t[k]]) {

	// Violations
	if (Q > Qmax) {

	  // Set data
	  j_old = BUS_get_index_v_mag(bus[k],t);
	  j_new = GEN_get_index_Q(gen,t);
	  b_new = Qmax;
	  switch_flag = TRUE;
	  reg_flag[bus_index_t[k]] = FALSE;

	  // Update vector of var values
	  while (gen) {
	    if (GEN_has_flags(gen,FLAG_VARS,GEN_VAR_Q))
	      VEC_set(var_values,GEN_get_index_Q(gen,t),GEN_get_Q_max(gen));
	    gen = GEN_get_reg_next(gen);
	  }
	}
	else if (Q < Qmin) {

	  // Set data
	  j_old = BUS_get_index_v_mag(bus[k],t);
	  j_new = GEN_get_index_Q(gen,t);
	  b_new = Qmin;
	  switch_flag = TRUE;
	  reg_flag[bus_index_t[k]] = FALSE;

	  // Update vector of var values
	  while (gen) {
	    if (GEN_has_flags(gen,FLAG_VARS,GEN_VAR_Q))
	      VEC_set(var_values,GEN_get_index_Q(gen,t),GEN_get_Q_min(gen));
	    gen = GEN_get_reg_next(gen);
	  }
	}
      }

      // Previously regulated
      else {

	// Q at Qmin and v < v_set
	if (fabs(Q-Qmin) < fabs(Q-Qmax) && v < v_set) {

	  Q = Q - VEC_get(f,BUS_get_index_Q(GEN_get_bus(gen))+t*2*num_buses); // per unit (see constr_PF)

	  if (Q >= Qmax) {

	    // Set data
	    j_old = GEN_get_index_Q(gen,t);
	    j_new = GEN_get_index_Q(gen,t);
	    b_new = Qmax;
	    switch_flag = TRUE;

	    // Update vector of var values
	    while (gen) {
	      if (GEN_has_flags(gen,FLAG_VARS,GEN_VAR_Q))
		VEC_set(var_values,GEN_get_index_Q(gen,t),GEN_get_Q_max(gen));
	      gen = GEN_get_reg_next(gen);
	    }
	  }
	  else if (Qmin < Q && Q < Qmax) {

	    // Set data
	    j_old = GEN_get_index_Q(gen,t);
	    j_new = BUS_get_index_v_mag(bus[k],t);
	    b_new = v_set;
	    switch_flag = TRUE;
	    reg_flag[bus_index_t[k]] = TRUE;

	    // Udpate vector of var values
	    VEC_set(var_values,j_new,b_new);
	  }
	}

	// Q at Qmax and v > v_set
	else if (fabs(Q-Qmax) < fabs(Q-Qmin) && v > v_set) {

	  Q = Q - VEC_get(f,BUS_get_index_Q(GEN_get_bus(gen))+t*2*num_buses); // per unit (see constr_PF)

	  if (Q <= Qmin) {

	    // Set data
	    j_old = GEN_get_index_Q(gen,t);
	    j_new = GEN_get_index_Q(gen,t);
	    b_new = Qmin;
	    switch_flag = TRUE;

	    // Update vector of var values
	    while (gen) {
	      if (GEN_has_flags(gen,FLAG_VARS,GEN_VAR_Q))
		VEC_set(var_values,GEN_get_index_Q(gen,t),GEN_get_Q_min(gen));
	      gen = GEN_get_reg_next(gen);
	    }
	  }
	  else if (Qmin < Q && Q < Qmax) {

	    // Set data
	    j_old = GEN_get_index_Q(gen,t);
	    j_new = BUS_get_index_v_mag(bus[k],t);
	    b_new = v_set;
	    switch_flag = TRUE;
	    reg_flag[bus_index_t[k]] = TRUE;

	    // Udpate vector of var values
	    VEC_set(var_values,j_new,b_new);
	  }
	}
      }

      // Update fix constraints
      if (switch_flag) {
	for (i = 0; i < MAT_get_nnz(A); i++) {
	  if (MAT_get_j(A,i) == j_old)
	    MAT_set_d(A,i,0.);
	  if (MAT_get_j(A,i) == j_new) {
	    MAT_set_d(A,i,1.);
	    VEC_set(b,MAT_get_i(A,i),b_new);
	  }
	}
      }
    }

    // Update counted flag
    bus_counted[bus_index_t[k]] = TRUE;
  }
}
Exemple #3
0
void CONSTR_FIX_count_step(Constr* c, Branch* br, int t) {

  // Local variables
  Bus* buses[2];
  Bus* bus;
  Gen* gen;
  Vargen* vargen;
  Shunt* shunt;
  Load* load;
  Bat* bat;
  int* A_nnz;
  int* A_row;
  char* bus_counted;
  int i;
  int T;

  // Number of periods
  T = BRANCH_get_num_periods(br);

  // Constr data
  A_nnz = CONSTR_get_A_nnz_ptr(c);
  A_row = CONSTR_get_A_row_ptr(c);
  bus_counted = CONSTR_get_bus_counted(c);

  // Check pointers
  if (!A_nnz || !A_row || !bus_counted)
    return;

  // Check outage
  if (BRANCH_is_on_outage(br))
    return;

  // Bus data
  buses[0] = BRANCH_get_bus_k(br);
  buses[1] = BRANCH_get_bus_m(br);

  // Tap ratio
  if (BRANCH_has_flags(br,FLAG_FIXED,BRANCH_VAR_RATIO) &&
      BRANCH_has_flags(br,FLAG_VARS,BRANCH_VAR_RATIO)) {
    (*A_nnz)++;
    (*A_row)++;
  }

  // Phase shift
  if (BRANCH_has_flags(br,FLAG_FIXED,BRANCH_VAR_PHASE) &&
      BRANCH_has_flags(br,FLAG_VARS,BRANCH_VAR_PHASE)) {
    (*A_nnz)++;
    (*A_row)++;
  }

  // Buses
  for (i = 0; i < 2; i++) {

    bus = buses[i];

    if (!bus_counted[BUS_get_index(bus)*T+t]) {

      // Voltage magnitude (V_MAG)
      if (BUS_has_flags(bus,FLAG_FIXED,BUS_VAR_VMAG) &&
	  BUS_has_flags(bus,FLAG_VARS,BUS_VAR_VMAG)) {
	(*A_nnz)++;

	// Extra nz for regulating generator (for PV-PQ switching?)
	if (BUS_is_regulated_by_gen(bus) &&
	    GEN_has_flags(BUS_get_reg_gen(bus),FLAG_VARS,GEN_VAR_Q))
	  (*A_nnz)++;

	(*A_row)++;
      }

      // Voltage angle (V_ANG)
      if (BUS_has_flags(bus,FLAG_FIXED,BUS_VAR_VANG) &&
	  BUS_has_flags(bus,FLAG_VARS,BUS_VAR_VANG)) {
	(*A_nnz)++;
	(*A_row)++;
      }

      // Generators
      for (gen = BUS_get_gen(bus); gen != NULL; gen = GEN_get_next(gen)) {

	// Active power (P)
	if (GEN_has_flags(gen,FLAG_FIXED,GEN_VAR_P) &&
	    GEN_has_flags(gen,FLAG_VARS,GEN_VAR_P)) {
	  (*A_nnz)++;
	  (*A_row)++;
	}

	// Reactive power (Q)
	if (GEN_has_flags(gen,FLAG_FIXED,GEN_VAR_Q) &&
	    GEN_has_flags(gen,FLAG_VARS,GEN_VAR_Q)) {
	  (*A_nnz)++;
	  (*A_row)++;
	}
      }

      // Variable generators
      for (vargen = BUS_get_vargen(bus); vargen != NULL; vargen = VARGEN_get_next(vargen)) {

	// Active power (P)
	if (VARGEN_has_flags(vargen,FLAG_FIXED,VARGEN_VAR_P) &&
	    VARGEN_has_flags(vargen,FLAG_VARS,VARGEN_VAR_P)) {
	  (*A_nnz)++;
	  (*A_row)++;
	}

	// Reactive power (Q)
	if (VARGEN_has_flags(vargen,FLAG_FIXED,VARGEN_VAR_Q) &&
	    VARGEN_has_flags(vargen,FLAG_VARS,VARGEN_VAR_Q)) {
	  (*A_nnz)++;
	  (*A_row)++;
	}
      }

      // Shunts
      for (shunt = BUS_get_shunt(bus); shunt != NULL; shunt = SHUNT_get_next(shunt)) {

	// Susceptance (b)
	if (SHUNT_has_flags(shunt,FLAG_FIXED,SHUNT_VAR_SUSC) &&
	    SHUNT_has_flags(shunt,FLAG_VARS,SHUNT_VAR_SUSC)) {
	  (*A_nnz)++;
	  (*A_row)++;
	}
      }

      // Batteries
      for (bat = BUS_get_bat(bus); bat != NULL; bat = BAT_get_next(bat)) {

	// Charging/discharging power (P)
	if (BAT_has_flags(bat,FLAG_FIXED,BAT_VAR_P) &&
	    BAT_has_flags(bat,FLAG_VARS,BAT_VAR_P)) {
	  (*A_nnz) += 2;
	  (*A_row) += 2;
	}

	// Energy level (E)
	if (BAT_has_flags(bat,FLAG_FIXED,BAT_VAR_E) &&
	    BAT_has_flags(bat,FLAG_VARS,BAT_VAR_E)) {
	  (*A_nnz)++;
	  (*A_row)++;
	}
      }

      // Loads
      for (load = BUS_get_load(bus); load != NULL; load = LOAD_get_next(load)) {

	// Active power (P)
	if (LOAD_has_flags(load,FLAG_FIXED,LOAD_VAR_P) &&
	    LOAD_has_flags(load,FLAG_VARS,LOAD_VAR_P)) {
	  (*A_nnz)++;
	  (*A_row)++;
	}
      }
    }

    // Update counted flag
    bus_counted[BUS_get_index(bus)*T+t] = TRUE;
  }
}
Exemple #4
0
void CONSTR_FIX_analyze_step(Constr* c, Branch* br, int t) {

  // Local variables
  Bus* buses[2];
  Bus* bus;
  Gen* gen;
  Vargen* vargen;
  Bat* bat;
  Load* load;
  Shunt* shunt;
  int* A_nnz;
  int* A_row;
  char* bus_counted;
  Vec* b;
  Mat* A;
  int i;
  REAL Pc;
  REAL Pd;
  int T;

  // Number of periods
  T = BRANCH_get_num_periods(br);

  // Cosntr data
  b = CONSTR_get_b(c);
  A = CONSTR_get_A(c);
  A_nnz = CONSTR_get_A_nnz_ptr(c);
  A_row = CONSTR_get_A_row_ptr(c);
  bus_counted = CONSTR_get_bus_counted(c);

  // Check pointers
  if (!A_nnz || !A_row || !bus_counted)
    return;

  // Check outage
  if (BRANCH_is_on_outage(br))
    return;

  // Bus data
  buses[0] = BRANCH_get_bus_k(br);
  buses[1] = BRANCH_get_bus_m(br);

  // Tap ratio
  if (BRANCH_has_flags(br,FLAG_FIXED,BRANCH_VAR_RATIO) &&
      BRANCH_has_flags(br,FLAG_VARS,BRANCH_VAR_RATIO)) {
    VEC_set(b,*A_row,BRANCH_get_ratio(br,t));
    MAT_set_i(A,*A_nnz,*A_row);
    MAT_set_j(A,*A_nnz,BRANCH_get_index_ratio(br,t));
    MAT_set_d(A,*A_nnz,1.);
    (*A_nnz)++;
    (*A_row)++;
  }

  // Phase shift
  if (BRANCH_has_flags(br,FLAG_FIXED,BRANCH_VAR_PHASE) &&
      BRANCH_has_flags(br,FLAG_VARS,BRANCH_VAR_PHASE)) {
    VEC_set(b,*A_row,BRANCH_get_phase(br,t));
    MAT_set_i(A,*A_nnz,*A_row);
    MAT_set_j(A,*A_nnz,BRANCH_get_index_phase(br,t));
    MAT_set_d(A,*A_nnz,1.);
    (*A_nnz)++;
    (*A_row)++;
  }

  // Buses
  for (i = 0; i < 2; i++) {

    bus = buses[i];

    if (!bus_counted[BUS_get_index(bus)*T+t]) {

      // Voltage magnitude (V_MAG)
      if (BUS_has_flags(bus,FLAG_FIXED,BUS_VAR_VMAG) &&
	  BUS_has_flags(bus,FLAG_VARS,BUS_VAR_VMAG)) {
	if (BUS_is_regulated_by_gen(bus))
	  VEC_set(b,*A_row,BUS_get_v_set(bus,t));
	else
	  VEC_set(b,*A_row,BUS_get_v_mag(bus,t));
	MAT_set_i(A,*A_nnz,*A_row);
	MAT_set_j(A,*A_nnz,BUS_get_index_v_mag(bus,t));
	MAT_set_d(A,*A_nnz,1.);
	(*A_nnz)++;

	// Extra nz for regulating generator (for PV-PQ switching?)
	if (BUS_is_regulated_by_gen(bus) &&
	    GEN_has_flags(BUS_get_reg_gen(bus),FLAG_VARS,GEN_VAR_Q)) {
	  MAT_set_i(A,*A_nnz,*A_row);
	  MAT_set_j(A,*A_nnz,GEN_get_index_Q(BUS_get_reg_gen(bus),t));
	  MAT_set_d(A,*A_nnz,0.); // placeholder
	  (*A_nnz)++;
	}

	(*A_row)++;
      }

      // Voltage angle (V_ANG)
      if (BUS_has_flags(bus,FLAG_FIXED,BUS_VAR_VANG) &&
	  BUS_has_flags(bus,FLAG_VARS,BUS_VAR_VANG)) {
	VEC_set(b,*A_row,BUS_get_v_ang(bus,t));
	MAT_set_i(A,*A_nnz,*A_row);
	MAT_set_j(A,*A_nnz,BUS_get_index_v_ang(bus,t));
	MAT_set_d(A,*A_nnz,1.);
	(*A_nnz)++;
	(*A_row)++;
      }

      // Generators
      for (gen = BUS_get_gen(bus); gen != NULL; gen = GEN_get_next(gen)) {

	// Active power (P)
	if (GEN_has_flags(gen,FLAG_FIXED,GEN_VAR_P) &&
	    GEN_has_flags(gen,FLAG_VARS,GEN_VAR_P)) {
	  VEC_set(b,*A_row,GEN_get_P(gen,t));
	  MAT_set_i(A,*A_nnz,*A_row);
	  MAT_set_j(A,*A_nnz,GEN_get_index_P(gen,t));
	  MAT_set_d(A,*A_nnz,1.);
	  (*A_nnz)++;
	  (*A_row)++;
	}

	// Reactive power (Q)
	if (GEN_has_flags(gen,FLAG_FIXED,GEN_VAR_Q) &&
	    GEN_has_flags(gen,FLAG_VARS,GEN_VAR_Q)) {
	  VEC_set(b,*A_row,GEN_get_Q(gen,t));
	  MAT_set_i(A,*A_nnz,*A_row);
	  MAT_set_j(A,*A_nnz,GEN_get_index_Q(gen,t));
	  MAT_set_d(A,*A_nnz,1.);
	  (*A_nnz)++;
	  (*A_row)++;
	}
      }

      // Variable generators
      for (vargen = BUS_get_vargen(bus); vargen != NULL; vargen = VARGEN_get_next(vargen)) {

	// Active power (P)
	if (VARGEN_has_flags(vargen,FLAG_FIXED,VARGEN_VAR_P) &&
	    VARGEN_has_flags(vargen,FLAG_VARS,VARGEN_VAR_P)) {
	  VEC_set(b,*A_row,VARGEN_get_P(vargen,t));
	  MAT_set_i(A,*A_nnz,*A_row);
	  MAT_set_j(A,*A_nnz,VARGEN_get_index_P(vargen,t));
	  MAT_set_d(A,*A_nnz,1.);
	  (*A_nnz)++;
	  (*A_row)++;
	}

	// Reactive power (Q)
	if (VARGEN_has_flags(vargen,FLAG_FIXED,VARGEN_VAR_Q) &&
	    VARGEN_has_flags(vargen,FLAG_VARS,VARGEN_VAR_Q)) {
	  VEC_set(b,*A_row,VARGEN_get_Q(vargen,t));
	  MAT_set_i(A,*A_nnz,*A_row);
	  MAT_set_j(A,*A_nnz,VARGEN_get_index_Q(vargen,t));
	  MAT_set_d(A,*A_nnz,1.);
	  (*A_nnz)++;
	  (*A_row)++;
	}
      }

      // Shunts
      for (shunt = BUS_get_shunt(bus); shunt != NULL; shunt = SHUNT_get_next(shunt)) {

	// Susceptance (b)
	if (SHUNT_has_flags(shunt,FLAG_FIXED,SHUNT_VAR_SUSC) &&
	    SHUNT_has_flags(shunt,FLAG_VARS,SHUNT_VAR_SUSC)) {
	  VEC_set(b,*A_row,SHUNT_get_b(shunt,t));
	  MAT_set_i(A,*A_nnz,*A_row);
	  MAT_set_j(A,*A_nnz,SHUNT_get_index_b(shunt,t));
	  MAT_set_d(A,*A_nnz,1.);
	  (*A_nnz)++;
	  (*A_row)++;
	}
      }

      // Batteries
      for (bat = BUS_get_bat(bus); bat != NULL; bat = BAT_get_next(bat)) {

	// Charging/discharging power (P)
	if (BAT_has_flags(bat,FLAG_FIXED,BAT_VAR_P) &&
	    BAT_has_flags(bat,FLAG_VARS,BAT_VAR_P)) {

	  if (BAT_get_P(bat,t) >= 0) {
	    Pc = BAT_get_P(bat,t);
	    Pd = 0.;
	  }
	  else {
	    Pc = 0.;
	    Pd = -BAT_get_P(bat,t);
	  }

	  // Pc
	  VEC_set(b,*A_row,Pc);
	  MAT_set_i(A,*A_nnz,*A_row);
	  MAT_set_j(A,*A_nnz,BAT_get_index_Pc(bat,t));
	  MAT_set_d(A,*A_nnz,1.);
	  (*A_nnz)++;
	  (*A_row)++;

	  // Pd
	  VEC_set(b,*A_row,Pd);
	  MAT_set_i(A,*A_nnz,*A_row);
	  MAT_set_j(A,*A_nnz,BAT_get_index_Pd(bat,t));
	  MAT_set_d(A,*A_nnz,1.);
	  (*A_nnz)++;
	  (*A_row)++;
	}

	// Energy level (E)
	if (BAT_has_flags(bat,FLAG_FIXED,BAT_VAR_E) &&
	    BAT_has_flags(bat,FLAG_VARS,BAT_VAR_E)) {
	  VEC_set(b,*A_row,BAT_get_E(bat,t));
	  MAT_set_i(A,*A_nnz,*A_row);
	  MAT_set_j(A,*A_nnz,BAT_get_index_E(bat,t));
	  MAT_set_d(A,*A_nnz,1.);
	  (*A_nnz)++;
	  (*A_row)++;
	}
      }

      // Loads
      for (load = BUS_get_load(bus); load != NULL; load = LOAD_get_next(load)) {

	// Active power (P)
	if (LOAD_has_flags(load,FLAG_FIXED,LOAD_VAR_P) &&
	    LOAD_has_flags(load,FLAG_VARS,LOAD_VAR_P)) {
	  VEC_set(b,*A_row,LOAD_get_P(load,t));
	  MAT_set_i(A,*A_nnz,*A_row);
	  MAT_set_j(A,*A_nnz,LOAD_get_index_P(load,t));
	  MAT_set_d(A,*A_nnz,1.);
	  (*A_nnz)++;
	  (*A_row)++;
	}
      }
    }

    // Update counted flag
    bus_counted[BUS_get_index(bus)*T+t] = TRUE;
  }
}
Exemple #5
0
void CONSTR_PAR_GEN_Q_analyze_branch(Constr* c, Branch* br) {
  
  // Local variables
  Bus* buses[2];
  Bus* bus;
  Gen* gen1;
  Gen* gen2;
  int* Acounter;
  int* Aconstr_index;
  char* bus_counted;
  Vec* b;
  Mat* A;
  int i;
  int j;
  REAL Qmin1;
  REAL Qmin2;
  REAL dQ1;
  REAL dQ2;
  
  // Cosntr data
  b = CONSTR_get_b(c);
  A = CONSTR_get_A(c);
  Acounter = CONSTR_get_Acounter_ptr(c);
  Aconstr_index = CONSTR_get_Aconstr_index_ptr(c);
  bus_counted = CONSTR_get_bus_counted(c);
  if (!Acounter || !Aconstr_index || !bus_counted)
    return;

  // Bus data
  buses[0] = BRANCH_get_bus_from(br);
  buses[1] = BRANCH_get_bus_to(br);

  // Buses
  for (i = 0; i < 2; i++) {
    
    bus = buses[i];
    
    if (!bus_counted[BUS_get_index(bus)]) {
      
      // Reactive power of regulating generators
      if (BUS_is_regulated_by_gen(bus)) {
	gen1 = BUS_get_reg_gen(bus);
	Qmin1 = GEN_get_Q_min(gen1);
	dQ1 = GEN_get_Q_max(gen1)-Qmin1;
	if (dQ1 < CONSTR_PAR_GEN_Q_PARAM)
	  dQ1 = CONSTR_PAR_GEN_Q_PARAM;
	for (gen2 = GEN_get_reg_next(gen1); gen2 != NULL; gen2 = GEN_get_reg_next(gen2)) {
	  Qmin2 = GEN_get_Q_min(gen2);
	  dQ2 = GEN_get_Q_max(gen2)-Qmin2;
	  if (dQ2 < CONSTR_PAR_GEN_Q_PARAM)
	    dQ2 = CONSTR_PAR_GEN_Q_PARAM;
	  VEC_set(b,*Aconstr_index,Qmin1/dQ1-Qmin2/dQ2);
	  if (GEN_has_flags(gen1,FLAG_VARS,GEN_VAR_Q)) {
	    MAT_set_i(A,*Acounter,*Aconstr_index);
	    MAT_set_j(A,*Acounter,GEN_get_index_Q(gen1));
	    MAT_set_d(A,*Acounter,1./dQ1);
	    (*Acounter)++;
	  }
	  else
	    VEC_add_to_entry(b,*Aconstr_index,-GEN_get_Q(gen1)/dQ1); 
	  if (GEN_has_flags(gen2,FLAG_VARS,GEN_VAR_Q)) {
	    MAT_set_i(A,*Acounter,*Aconstr_index);
	    MAT_set_j(A,*Acounter,GEN_get_index_Q(gen2));	      
	    MAT_set_d(A,*Acounter,-1./dQ2);
	    (*Acounter)++;
	  }
	  else
	    VEC_add_to_entry(b,*Aconstr_index,GEN_get_Q(gen2)/dQ2); 
	  (*Aconstr_index)++;
	}
      }
    }

    // Update counted flag
    bus_counted[BUS_get_index(bus)] = TRUE;    
  }  
}