Static Synchronous Compensator (SSC)

We implement the FACTS devices based on the following source:

A. Panosyan, “Modeling of advanced power transmission system controllers”, Ph.D. dissertation, Gottfried Wilhelm Leibniz Universität Hannover, 2010.

The Static Synchronous Compensator (SSC), also known as STATCOM, is a shunt connected Flexible AC Transmission System (FACTS) controller. It connects an AC system to a Voltage Source Converter (VSC) through a coupling transformer. The SSC is used for reactive shunt compensation. Since the VSC is not connected to a power source, there is no active power exchange between the SSC and the AC system. Consequently, the SSC can only control the voltage magnitude of the AC system.

Create Function

pandapower.create.create_ssc(net, bus, r_ohm, x_ohm, set_vm_pu=1.0, vm_internal_pu=1.0, va_internal_degree=0.0, name=None, controllable=True, in_service=True, index=None, **kwargs)

Creates an SSC element (STATCOM)- a shunt element with adjustable VSC internal voltage used to control the voltage at the connected bus

Does not work if connected to “PV” bus (gen bus, ext_grid bus)

INPUT:

net (pandapowerNet) - The pandapower network in which the element is created

bus (int) - connection bus of the ssc

r_ohm (float) - resistance of the coupling transformer component of ssc

x_ohm (float) - reactance of the coupling transformer component of ssc

set_vm_pu (float) - set-point for the bus voltage magnitude at the connection bus

vm_internal_pu (float) - The voltage magnitude of the voltage source converter VSC at the ssc component.: if the amplitude of the VSC output voltage is increased above that of the ac system voltage, the VSC behaves as a capacitor and reactive power is supplied to the ac system, decreasing the output voltage below that of the ac system leads to the VSC consuming reactive power acting as reactor.(source PhD Panosyan)

va_internal_degree (float) - The voltage angle of the voltage source converter VSC at the ssc component.

OPTIONAL:

name (list of strs, None) - element name

controllable (bool, True) - whether the element is considered as actively controlling or: as a fixed shunt impedance

in_service (bool, True) - True for in_service or False for out of service

index (int, None) - Force a specified ID if it is available. If None, the: index one higher than the highest already existing index is selected.

OUTPUT:

index (int) - The unique ID of the created ssc

Input Parameters

net.ssc

Parameter	Datatype	Value Range	Explanation
name	string		name of the SSC
bus*	integer		index of bus where the SSC is connected
r_ohm*	float	\(\geq\) 0	resistance of the coupling transformer component of SSC
x_ohm*	float	\(\leq\) 0	reactance of the coupling transformer component of SSC
set_vm_pu*	float		set-point for the bus voltage magnitude at the connection bus
vm_internal_pu*	float		The voltage magnitude of the voltage source converter VSC at the SSC component.
va_internal_degree*	float		The voltage angle of the voltage source converter VSC at the SSC component.
controllable*	boolean	True / False	whether the element is considered as actively controlling or as a fixed shunt impedance
in_service*	boolean	True / False	specifies if the SSC is in service.

*necessary for executing a power flow calculation.

Electric Model

The SSC is a VSC-based shunt-connected FACTS controller and can thus be modeled as a single-terminal active component. The corresponding terminal-admittance equation is given as:

\begin{align*} \underline{Y}_{T} (\underline{U}_{1} - \underline{U}_{VSC}) = \underline{I}_{1} \end{align*}

Where \(\underline{Y}_{T}\) = 1/\(\underline{Z}_{T}\) is the admittance of the lossless-assumed coupling transformer between the VSC and the ac system. \(\underline{U}_{VSC}\) stands for the VSC output Voltage.

Result Parameters

net.res_ssc

Parameter	Datatype	Explanation
q_mvar	float	shunt reactive power consumption of ssc [MVAr]
vm_internal_pu	float	voltage magnitude at ssc internal bus [pu]
va_internal_degree	float	voltage angle at ssc internal bus [degree]
vm_pu	float	voltage magnitude at ssc bus [pu]
va_degree	float	voltage angle at ssc bus [degree]