Load

ZIP demand: constant-power, constant-current, and constant-impedance parts.

Model Parameters

Symbol	Units	Data	Description	Note
\(P\)	[p.u.]	`P`	Constant-power active demand	Default 0
\(Q\)	[p.u.]	`Q`	Constant-power reactive demand	Default 0
\(P_I\)	[p.u.]	`Pi`	Constant-current active demand at 1 p.u.	Default 0
\(Q_I\)	[p.u.]	`Qi`	Constant-current reactive demand at 1 p.u.	Default 0
\(P_Z\)	[p.u.]	`Pz`	Constant-impedance active demand at 1 p.u.	Default 0
\(Q_Z\)	[p.u.]	`Qz`	Constant-impedance reactive demand at 1 p.u.	Default 0
\(u\)	[-]	`in_service`	Service status	Default true

Parameter Validation

None.

Model Derived Parameters

None.

Model Ports

Name	Port	Description
`bus`	Bus	Port bus

Model Variables

Internal Variables

None.

External Variables

Symbol	Units	Description	Note
\(V_\mathrm{r}\)	[p.u.]	Real voltage	Owned by the bus
\(V_\mathrm{i}\)	[p.u.]	Imaginary voltage	Owned by the bus

Model Equations

Objective

None.

Internal Constraints

Equality

None.

Inequality

None.

External Constraints

With \(|V| = \sqrt{V_\mathrm{r}^2 + V_\mathrm{i}^2}\), power into the bus, added to its balance:

\[\begin{split}\begin{aligned} \Delta P^\mathrm{bus} &\mathrel{+}= -u (P + P_I |V| + P_Z |V|^2) \\ \Delta Q^\mathrm{bus} &\mathrel{+}= -u (Q + Q_I |V| + Q_Z |V|^2) \end{aligned}\end{split}\]

Initialization

None.