4.4 runpf

In Matpower, a power flow is executed by calling runpf with a case struct or case file name as the first argument (casedata). In addition to printing output to the screen, which it does by default, runpf optionally returns the solution in a results struct.

The results struct is a superset of the input Matpower case struct mpc, with some additional fields as well as additional columns in some of the existing data fields. The solution values are stored as shown in Table 4-1.

name	default	description
model	'AC'	AC vs. DC modeling for power flow and OPF formulation
		'AC' – use AC formulation and corresponding alg options 'DC' – use DC formulation and corresponding alg options –
pf.alg	'NR'	AC power flow algorithm:
		'NR' – Newtons’s method (formulation depends on values of pf.current_balance and pf.v_cartesian options) 'NR-SC' – Newtons’s method (power mismatch, cartesian)† 'NR-IP' – Newtons’s method (current mismatch, polar)† 'NR-IC' – Newtons’s method (current mismatch, cartesian)† 'FDXB' – Fast-Decoupled (XB version) 'FDBX' – Fast-Decouple (BX version) 'GS' – Gauss-Seidel 'PQSUM' – Power Summation (radial networks only) 'ISUM' – Current Summation (radial networks only) 'YSUM' – Admittance Summation (radial networks only) –
pf.current_balance‡	0	use current, as opposed to power, balance for AC PF, 0 or 1
pf.v_cartesian‡	0	use cartesian, as opposed to polar, representation for voltages for AC PF, 0 or 1
pf.tol		termination tolerance on per unit P and Q dispatch
pf.nr.max_it	10	maximum number of iterations for Newton’s method
pf.nr.lin_solver	''	linear solver option for mplinsolve for computing Newton update step
		(see mplinsolve for complete list of all options)
		'' – default to '∖' for small systems, 'LU3' for larger ones '∖' – built-in backslash operator 'LU' – explicit default LU decomposition and back substitution 'LU3' – 3 output arg form of lu, Gilbert-Peierls algorithm with approximate minimum degree (AMD) reordering 'LU4' – 4 output arg form of lu, UMFPACK solver (same as 'LU') 'LU5' – 5 output arg form of lu, UMFPACK solver w/row scaling –
pf.fd.max_it	30	maximum number of iterations for fast-decoupled method
pf.gs.max_it	1000	maximum number of iterations for Gauss-Seidel method
pf.radial.max_it	20	maximum number of iterations for radial power flow methods
pf.radial.vcorr	0	perform voltage correction procedure in distribution power flow
		0 – do not perform voltage correction 1 – perform voltage correction –
pf.enforce_q_lims	0	enforce gen reactive power limits at expense of
		0 – do not enforce limits 1 – enforce limits, simultaneous bus type conversion 2 – enforce limits, one-at-a-time bus type conversion –

^† Automatically sets/overrides pf.current_balance and pf.v_cartesian options with corresponding values. ^‡ Only relevant for Newton power flow solver.

Additional optional input arguments can be used to set options (mpopt) and provide file names for saving the pretty printed output (fname) or the solved case data (solvedcase).

The options that control the power flow simulation are listed in Table 4-2 and those controlling the output printed to the screen in Table 4-3.

By default, runpf solves an AC power flow problem using a standard Newton’s method solver. To run a DC power flow, the model option must be set to 'DC'. For convenience, Matpower provides a function rundcpf which is simply a wrapper that sets the model option to 'DC' before calling runpf.

name	default	description
verbose	1	amount of progress info to be printed
		0 – print no progress info 1 – print a little progress info 2 – print a lot of progress info 3 – print all progress info –
out.all	-1	controls pretty-printing of results
		-1 – individual flags control what is printed 0 – do not print anything† 1 – print everything† –
out.sys_sum	1	print system summary (0 or 1)
out.area_sum	0	print area summaries (0 or 1)
out.bus	1	print bus detail, includes per bus gen info (0 or 1)
out.branch	1	print branch detail (0 or 1)
out.gen	0	print generator detail (0 or 1)
out.force	0	print results even if success flag = 0 (0 or 1)
out.suppress_detail	-1	suppress all output but system summary
		-1 – suppress details for large systems ( 500 buses) 0 – do not suppress any output specified by other flags 1 – suppress all output except system summary section† –

^† Overrides individual flags, but (in the case of out.suppress_detail) not out.all = 1.

Internally, the runpf function does a number of conversions to the problem data before calling the appropriate solver routine for the selected power flow algorithm. This external-to-internal format conversion is performed by the ext2int function, described in more detail in Section 7.3.1, and includes the elimination of out-of-service equipment and the consecutive renumbering of buses. All computations are done using this internal indexing. When the simulation has completed, the data is converted back to external format by int2ext before the results are printed and returned.