Common Parameters: u, name

Available models: PQ

## PQ#

Implements an automatic pq2z conversion during power flow when the voltage is outside [vmin, vmax]. The conversion can be turned off by setting pq2z to 0 in the Config file.

Before time-domain simulation, PQ load will be converted to impedance, current source, and power source based on the weights in the Config file.

Weights (p2p, p2i, p2z) corresponds to the weights for constant power, constant current and constant impedance. p2p, p2i and p2z must be in decimal numbers and sum up exactly to 1. The same rule applies to (q2q, q2i, q2z).

To alter the PQ load in terms of power during simulation, one needs to set the conversion weights to preserve the constant power portion. For example, the PQ can remain as constant power load by setting

ss.PQ.config.p2p = 1.0 ss.PQ.config.p2i = 0 ss.PQ.config.p2z = 0

ss.PQ.config.q2q = 1.0 ss.PQ.config.q2i = 0 ss.PQ.config.q2z = 0


Then, the constant power portion can be altered by changing the Ppf and Qpf constants for active power and reactive power.

The equivalent constant current components are in constants Ipeq and Iqeq for active and reactive current, and the equivalent impedances are in Req and Xeq.

### Parameters#

Name

Symbol

Description

Default

Unit

Properties

idx

unique device idx

u

$$u$$

connection status

1

bool

name

device name

bus

mandatory

Vn

$$V_n$$

AC voltage rating

110

kV

non_zero

p0

$$p_0$$

active power load in system base

0

p.u.

q0

$$q_0$$

reactive power load in system base

0

p.u.

vmax

$$v_{max}$$

max voltage before switching to impedance

1.200

vmin

$$v_{min}$$

min voltage before switching to impedance

0.800

owner

owner idx

### Variables#

Name

Symbol

Type

Description

Unit

Properties

a

$$\theta$$

ExtAlgeb

v

$$V$$

ExtAlgeb

### Initialization Equations#

Name

Symbol

Type

Initial Value

a

$$\theta$$

ExtAlgeb

v

$$V$$

ExtAlgeb

### Algebraic Equations#

Name

Symbol

Type

RHS of Equation "0 = g(x, y)"

a

$$\theta$$

ExtAlgeb

$$u \left(I_{peq} V \gamma_{p2i} + P_{pf} \gamma_{p2p} + R_{eq} V^{2} \gamma_{p2z}\right) \operatorname{Indicator}{\left(t_{dae} > 0 \right)} + u \left(R_{lb} V^{2} z_{l}^{vcmp} + R_{ub} V^{2} z_{u}^{vcmp} + p_{0} z_{i}^{vcmp}\right) \operatorname{Indicator}{\left(t_{dae} \leq 0 \right)}$$

v

$$V$$

ExtAlgeb

$$u \left(I_{qeq} V \gamma_{q2i} + Q_{pf} \gamma_{q2q} + V^{2} X_{eq} \gamma_{q2z}\right) \operatorname{Indicator}{\left(t_{dae} > 0 \right)} + u \left(V^{2} X_{lb} z_{l}^{vcmp} + V^{2} X_{ub} z_{u}^{vcmp} + q_{0} z_{i}^{vcmp}\right) \operatorname{Indicator}{\left(t_{dae} \leq 0 \right)}$$

### Services#

Name

Symbol

Equation

Type

Rub

$$R_{ub}$$

$$\frac{p_{0}}{v_{max}^{2}}$$

ConstService

Xub

$$X_{ub}$$

$$\frac{q_{0}}{v_{max}^{2}}$$

ConstService

Rlb

$$R_{lb}$$

$$\frac{p_{0}}{v_{min}^{2}}$$

ConstService

Xlb

$$X_{lb}$$

$$\frac{q_{0}}{v_{min}^{2}}$$

ConstService

Ppf

$$P_{pf}$$

$$R_{lb} V_{0}^{2} z_{l}^{vcmp} + R_{ub} V_{0}^{2} z_{u}^{vcmp} + p_{0} z_{i}^{vcmp}$$

ConstService

Qpf

$$Q_{pf}$$

$$V_{0}^{2} X_{lb} z_{l}^{vcmp} + V_{0}^{2} X_{ub} z_{u}^{vcmp} + q_{0} z_{i}^{vcmp}$$

ConstService

Req

$$R_{eq}$$

$$\frac{P_{pf}}{V_{0}^{2}}$$

ConstService

Xeq

$$X_{eq}$$

$$\frac{Q_{pf}}{V_{0}^{2}}$$

ConstService

Ipeq

$$I_{peq}$$

$$\frac{P_{pf}}{V_{0}}$$

ConstService

Iqeq

$$I_{qeq}$$

$$\frac{Q_{pf}}{V_{0}}$$

ConstService

### Discretes#

Name

Symbol

Type

Info

vcmp

$$vcmp$$

Limiter

Config Fields in [PQ]

Option

Symbol

Value

Info

Accepted values

1

allow adjusting upper or lower limits

(0, 1)

0

(0, 1)

1

(0, 1)

pq2z

$$z_{pq2z}$$

1

pq2z conversion if out of voltage limits

(0, 1)

p2p

$$\gamma_{p2p}$$

0

P constant power percentage for TDS. Must have (p2p+p2i+p2z)=1

float

p2i

$$\gamma_{p2i}$$

0

P constant current percentage

float

p2z

$$\gamma_{p2z}$$

1

P constant impedance percentage

float

q2q

$$\gamma_{q2q}$$

0

Q constant power percentage for TDS. Must have (q2q+q2i+q2z)=1

float

q2i

$$\gamma_{q2i}$$

0

Q constant current percentage

float

q2z

$$\gamma_{q2z}$$

1

Q constant impedance percentage

float