Shunt

Create Function

Input Parameters

net.shunt

Parameter	Datatype	Value Range	Explanation
name	string		name of the shunt
bus*	integer		index of bus where the impedance starts
p_mw*	float	\(\geq\) 0	shunt active power in MW at v= 1.0 p.u.
q_mvar*	float		shunt reactive power in kvar at v= 1.0 p.u.
vn_kv*	float	\(>\) 0	rated voltage of the shunt element
step*	integer	\(\geq\) 1	step position of the shunt
in_service*	boolean	True / False	specifies if the shunt is in service.

*necessary for executing a power flow calculation.

Electric Model

The power values are given at \(v = 1\) pu and are scaled linearly with the number of steps:

\begin{align*} \underline{S}_{shunt, ref} &= (p\_mw + j \cdot q\_mvar) \cdot step \end{align*}

Since \(\underline{S}_{shunt, ref}\) is the apparent power at the nominal voltage, we know that:

\begin{align*} \underline{Y}_{shunt} = \frac{\underline{S}_{shunt, ref}}{vn\_kv^2} \end{align*}

Converting to the per unit system results in:

\begin{align*} \underline{y}_{shunt} &= \frac{\underline{S}_{shunt, ref}}{V_{N}^2} \cdot Z_{N}\\ &= \frac{\underline{S}_{shunt, ref}}{V_{N}^2} \cdot \frac{V_{N}^2}{S_{N}} \\ &= \frac{S_{shunt, ref}}{S_{N}} \end{align*}

with the reference values for the per unit system as defined in Unit Systems and Conventions.

Result Parameters

net.res_shunt

Parameter	Datatype	Explanation
p_mw	float	shunt active power consumption [MW]
q_mvar	float	shunt reactive power consumption [MVAr]
vm_pu	float	voltage magnitude at shunt bus [pu]

\begin{align*} p\_mw &= Re(\underline{v}_{bus} \cdot \underline{i}_{shunt}) \\ q\_mvar &= Im(\underline{v}_{bus} \cdot \underline{i}_{shunt}) \\ vm\_pu &= v_{bus} \end{align*}