pypower.fdpf

29 """Solves the power flow using a fast decoupled method. 30 31 Solves for bus voltages given the full system admittance matrix (for 32 all buses), the complex bus power injection vector (for all buses), 33 the initial vector of complex bus voltages, the FDPF matrices B prime 34 and B double prime, and column vectors with the lists of bus indices 35 for the swing bus, PV buses, and PQ buses, respectively. The bus voltage 36 vector contains the set point for generator (including ref bus) 37 buses, and the reference angle of the swing bus, as well as an initial 38 guess for remaining magnitudes and angles. C{ppopt} is a PYPOWER options 39 vector which can be used to set the termination tolerance, maximum 40 number of iterations, and output options (see L{ppoption} for details). 41 Uses default options if this parameter is not given. Returns the 42 final complex voltages, a flag which indicates whether it converged 43 or not, and the number of iterations performed. 44 45 @see: L{runpf} 46 47 @author: Ray Zimmerman (PSERC Cornell) 48 @author: Richard Lincoln 49 """ 50 if ppopt is None: 51 ppopt = ppoption() 52 53 ## options 54 tol = ppopt['PF_TOL'] 55 max_it = ppopt['PF_MAX_IT_FD'] 56 verbose = ppopt['VERBOSE'] 57 58 ## initialize 59 converged = 0 60 i = 0 61 V = V0 62 Va = angle(V) 63 Vm = abs(V) 64 65 ## set up indexing for updating V 66 #npv = len(pv) 67 #npq = len(pq) 68 pvpq = r_[pv, pq] 69 70 ## evaluate initial mismatch 71 mis = (V * conj(Ybus * V) - Sbus) / Vm 72 P = mis[pvpq].real 73 Q = mis[pq].imag 74 75 ## check tolerance 76 normP = linalg.norm(P, Inf) 77 normQ = linalg.norm(Q, Inf) 78 if verbose > 0: 79 alg = ppopt['PF_ALG'] 80 s = 'XB' if alg == 2 else 'BX' 81 sys.stdout.write('(fast-decoupled, %s)\n' % s) 82 if verbose > 1: 83 sys.stdout.write('\niteration max mismatch (p.u.) ') 84 sys.stdout.write('\ntype # P Q ') 85 sys.stdout.write('\n---- ---- ----------- -----------') 86 sys.stdout.write('\n - %3d %10.3e %10.3e' % (i, normP, normQ)) 87 if normP < tol and normQ < tol: 88 converged = 1 89 if verbose > 1: 90 sys.stdout.write('\nConverged!\n') 91 92 ## reduce B matrices 93 Bp = Bp[array([pvpq]).T, pvpq].tocsc() # splu requires a CSC matrix 94 Bpp = Bpp[array([pq]).T, pq].tocsc() 95 96 ## factor B matrices 97 Bp_solver = splu(Bp) 98 Bpp_solver = splu(Bpp) 99 100 ## do P and Q iterations 101 while (not converged and i < max_it): 102 ## update iteration counter 103 i = i + 1 104 105 ##----- do P iteration, update Va ----- 106 dVa = -Bp_solver.solve(P) 107 108 ## update voltage 109 Va[pvpq] = Va[pvpq] + dVa 110 V = Vm * exp(1j * Va) 111 112 ## evalute mismatch 113 mis = (V * conj(Ybus * V) - Sbus) / Vm 114 P = mis[pvpq].real 115 Q = mis[pq].imag 116 117 ## check tolerance 118 normP = linalg.norm(P, Inf) 119 normQ = linalg.norm(Q, Inf) 120 if verbose > 1: 121 sys.stdout.write("\n %s %3d %10.3e %10.3e" % 122 (type,i, normP, normQ)) 123 if normP < tol and normQ < tol: 124 converged = 1 125 if verbose: 126 sys.stdout.write('\nFast-decoupled power flow converged in %d ' 127 'P-iterations and %d Q-iterations.\n' % (i, i - 1)) 128 break 129 130 ##----- do Q iteration, update Vm ----- 131 dVm = -Bpp_solver.solve(Q) 132 133 ## update voltage 134 Vm[pq] = Vm[pq] + dVm 135 V = Vm * exp(1j * Va) 136 137 ## evalute mismatch 138 mis = (V * conj(Ybus * V) - Sbus) / Vm 139 P = mis[pvpq].real 140 Q = mis[pq].imag 141 142 ## check tolerance 143 normP = linalg.norm(P, Inf) 144 normQ = linalg.norm(Q, Inf) 145 if verbose > 1: 146 sys.stdout.write('\n Q %3d %10.3e %10.3e' % (i, normP, normQ)) 147 if normP < tol and normQ < tol: 148 converged = 1 149 if verbose: 150 sys.stdout.write('\nFast-decoupled power flow converged in %d ' 151 'P-iterations and %d Q-iterations.\n' % (i, i)) 152 break 153 154 if verbose: 155 if not converged: 156 sys.stdout.write('\nFast-decoupled power flow did not converge in ' 157 '%d iterations.' % i) 158 159 return V, converged, i

Source Code for Module pypower.fdpf