PYPOWER#

AMS includes PYPOWER cases in version 2 for dispatch modeling and analysis. PYPOWER cases follow the same format as MATPOWER.

The PYPOWER case is defined as a Python dictionary that includes bus, gen, branch, areas, and gencost. Defines the PYPOWER case file format.

A PYPOWER case file is a Python file or MAT-file that defines or returns a dict named ppc, referred to as a "PYPOWER case dict". The keys of this dict are bus, gen, branch, areas, and gencost. With the exception of C{baseMVA}, a scalar, each data variable is an array, where a row corresponds to a single bus, branch, gen, etc. The format of the data is similar to the PTI format described in PTI Load Flow Data Format.

Example Case9#

ppc = {"version": '2'}

##-----  Power Flow Data  -----##
## system MVA base
ppc["baseMVA"] = 100.0

## bus data
# bus_i type Pd Qd Gs Bs area Vm Va baseKV zone Vmax Vmin
ppc["bus"] = array([
    [1, 3, 0,    0, 0, 0, 1, 1, 0, 345, 1, 1.1, 0.9],
    [2, 2, 0,    0, 0, 0, 1, 1, 0, 345, 1, 1.1, 0.9],
    [3, 2, 0,    0, 0, 0, 1, 1, 0, 345, 1, 1.1, 0.9],
    [4, 1, 0,    0, 0, 0, 1, 1, 0, 345, 1, 1.1, 0.9],
    [5, 1, 90,  30, 0, 0, 1, 1, 0, 345, 1, 1.1, 0.9],
    [6, 1, 0,    0, 0, 0, 1, 1, 0, 345, 1, 1.1, 0.9],
    [7, 1, 100, 35, 0, 0, 1, 1, 0, 345, 1, 1.1, 0.9],
    [8, 1, 0,    0, 0, 0, 1, 1, 0, 345, 1, 1.1, 0.9],
    [9, 1, 125, 50, 0, 0, 1, 1, 0, 345, 1, 1.1, 0.9]
])

## generator data
# bus, Pg, Qg, Qmax, Qmin, Vg, mBase, status, Pmax, Pmin, Pc1, Pc2,
# Qc1min, Qc1max, Qc2min, Qc2max, ramp_agc, ramp_10, ramp_30, ramp_q, apf
ppc["gen"] = array([
    [1, 0,   0, 300, -300, 1, 100, 1, 250, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [2, 163, 0, 300, -300, 1, 100, 1, 300, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
    [3, 85,  0, 300, -300, 1, 100, 1, 270, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
])

## branch data
# fbus, tbus, r, x, b, rateA, rateB, rateC, ratio, angle, status, angmin, angmax
ppc["branch"] = array([
    [1, 4, 0,      0.0576, 0,     250, 250, 250, 0, 0, 1, -360, 360],
    [4, 5, 0.017,  0.092,  0.158, 250, 250, 250, 0, 0, 1, -360, 360],
    [5, 6, 0.039,  0.17,   0.358, 150, 150, 150, 0, 0, 1, -360, 360],
    [3, 6, 0,      0.0586, 0,     300, 300, 300, 0, 0, 1, -360, 360],
    [6, 7, 0.0119, 0.1008, 0.209, 150, 150, 150, 0, 0, 1, -360, 360],
    [7, 8, 0.0085, 0.072,  0.149, 250, 250, 250, 0, 0, 1, -360, 360],
    [8, 2, 0,      0.0625, 0,     250, 250, 250, 0, 0, 1, -360, 360],
    [8, 9, 0.032,  0.161,  0.306, 250, 250, 250, 0, 0, 1, -360, 360],
    [9, 4, 0.01,   0.085,  0.176, 250, 250, 250, 0, 0, 1, -360, 360]
])

##-----  OPF Data  -----##
## area data
# area refbus
ppc["areas"] = array([
    [1, 5]
])

## generator cost data
# 1 startup shutdown n x1 y1 ... xn yn
# 2 startup shutdown n c(n-1) ... c0
ppc["gencost"] = array([
    [2, 1500, 0, 3, 0.11,   5,   150],
    [2, 2000, 0, 3, 0.085,  1.2, 600],
    [2, 3000, 0, 3, 0.1225, 1,   335]
])

Version Information#

There are two versions of the PYPOWER case file format. The current version of PYPOWER uses version 2 of the PYPOWER case format internally and includes a version field with a value of 2 to make the version explicit. Earlier versions of PYPOWER used the version 1 case format, which defined the data matrices as individual variables, as opposed to keys of a dict. Case files in version 1 format with OPF data also included an (unused) areas variable. While the version 1 format has now been deprecated, it is still handled automatically by loadcase and savecase which are able to load and save case files in both version 1 and version 2 formats.

See also doc for idx_bus, idx_brch, idx_gen, idx_area and idx_cost regarding constants which can be used as named column indices for the data matrices. Also described in the first three are additional results columns that are added to the bus, branch, and gen matrices by the power flow and OPF solvers.

The case dict also allows for additional fields to be included. The OPF is designed to recognize fields named A, l, u, H, Cw, N, fparm, z0, zl, and zu as parameters used to directly extend the OPF formulation (see doc for opf for details). Other user-defined fields may also be included and will be automatically loaded by the loadcase function and, given an appropriate 'savecase' callback function (see doc for add_userfcn), saved by the savecase function.

Bus#

bus number (positive integer)
bus type - PQ bus = 1 - PV bus = 2 - reference bus = 3 - isolated bus = 4
Pd, real power demand (MW)
Qd, reactive power demand (MVAr)
Gs, shunt conductance (MW demanded at V = 1.0 p.u.)
Bs, shunt susceptance (MVAr injected at V = 1.0 p.u.)
area number (positive integer)
Vm, voltage magnitude (p.u.)
Va, voltage angle (degrees)
baseKV, base voltage (kV)
zone, loss zone (positive integer)
maxVm, maximum voltage magnitude (p.u.)
minVm, minimum voltage magnitude (p.u.)

Generator#

bus number
Pg, real power output (MW)
Qg, reactive power output (MVAr)
Qmax, maximum reactive power output (MVAr)
Qmin, minimum reactive power output (MVAr)
Vg, voltage magnitude setpoint (p.u.)
mBase, total MVA base of this machine, defaults to baseMVA
status - > 0 - machine in service - <= 0 - machine out of service
Pmax, maximum real power output (MW)
Pmin, minimum real power output (MW)
Pc1, lower real power output of PQ capability curve (MW)
Pc2, upper real power output of PQ capability curve (MW)
Qc1min, minimum reactive power output at Pc1 (MVAr)
Qc1max, maximum reactive power output at Pc1 (MVAr)
Qc2min, minimum reactive power output at Pc2 (MVAr)
Qc2max, maximum reactive power output at Pc2 (MVAr)
ramp rate for load following/AGC (MW/min)
ramp rate for 10-minute reserves (MW)
ramp rate for 30-minute reserves (MW)
ramp rate for reactive power (2-sec timescale) (MVAr/min)
APF, area participation factor

Branch#

f, from bus number
t, to bus number
r, resistance (p.u.)
x, reactance (p.u.)
b, total line charging susceptance (p.u.)
rateA, MVA rating A (long-term rating)
rateB, MVA rating B (short-term rating)
rateC, MVA rating C (emergency rating)
ratio, transformer off nominal turns ratio (= 0 for lines)
angle, transformer phase shift angle (degrees), positive -> delay
- (Gf, shunt conductance at from bus p.u.)
- (Bf, shunt susceptance at from bus p.u.)
- (Gt, shunt conductance at to bus p.u.)
- (Bt, shunt susceptance at to bus p.u.)
initial branch status, 1 - in service, 0 - out of service
minimum angle difference, angle(Vf) - angle(Vt) (degrees)
maximum angle difference, angle(Vf) - angle(Vt) (degrees)

Generator Cost#

Note

If gen has ng rows, then the first ng rows of gencost contain the cost for active power produced by the corresponding generators. If gencost has $2 \times ng$ rows then rows $ng + 1$ to $2 \times ng$ contain the reactive power costs in the same format.

model, 1 - piecewise linear, 2 - polynomial
startup, startup cost in US dollars
shutdown, shutdown cost in US dollars
N, number of cost coefficients to follow for polynomial cost function, or number of data points for piecewise linear. The following parameters define the total cost function f(p), where units of f and p are $/hr and MW (or MVAr), respectively.
- For MODEL = 1: p0, f0, p1, f1, ..., pn, fn where p0 < p1 < ... < pn and the cost f(p) is defined by the coordinates (p0,f0), (p1,f1), ..., (pn,fn) of the end/break-points of the piecewise linear cost function.
- For MODEL = 2: cn, ..., c1, c0 n + 1 coefficients of an n-th order polynomial cost function, starting with the highest order, where cost is $f(p) = c_n \times p^n + \ldots + c_1 \times p + c_0$.

Area (deprecated)#

Note

This data is not used by PYPOWER and is no longer necessary for version 2 case files with OPF data.

i, area number
price_ref_bus, reference bus for that area