Static VAR Compensator

This component represents a 12-pulse Thyristor Switched Capacitor (TSC) / Thyristor Controlled Reactor (TCR) Static VAR Compensator (SVC) system.

The model includes its own transformer, which consists of a star connected primary winding and dual secondary windings (one star and a one delta connected). The user may select the limits of absorption (inductive) and production (capacitive) of the SVC, as well as, the number of TSC stages. The MVA rating of each equal stage is determined by dividing the production limit by the number of stages.

Input Parameters

Rated Frequency	REAL	Constant	The system rated frequency [Hz]

3 Phase Transformer MVA	REAL	Constant	The 3-phase MVA rating of the internal SVC transformer [MVA]

Firing Pulses From:	Choice		Select Internal PLO or External. This gives the user a choice between using the internal Phase Locked Oscillator (PLO) or, a user defined, external firing pulse generation circuit. See Internal Control System for more details

# of Steps per Main Time Step	INTEGER	Constant	This input (NS1) sets the SVC time step, where:

# of Steps per NS1 During Switching	INTEGER	Constant	This input (NS2) sets the SVC time step during TCR switching, where: For an EMTDC time step of 25 ms, NS1 = 1 and NS2 = 5 is recommended

# of Capacitor Stages	INTEGER	Constant	The total number of TSC stages. The total capacitive MVA selected for this SVC will be divided into equal TSC stages according to this number (i.e. if the total capacitive MVA is 500, and there are 5 stages, each TSC stage will be 100 MVA)

Initial # of TSC Stages On	INTEGER	Constant	The initial number of TSC stages on at the start of the simulation. Once the simulation is started, the number TSC branches on can be controlled by signaling the CSW input

Scaling Factor	REAL	Constant	This input allows the user to size the SVC based on the one set of data. If no scaling is desired, enter 1.0

Graphics Display	Choice		Select 3 phase view, or Single line view

PLO Proportional Gain	REAL	Constant	The proportional gain for the internal Phase Locked Oscillator (PLO). A value of 100 is recommended

PLO Integral Gain	REAL	Constant	The integral gain for the internal Phase Locked Oscillator (PLO). A value of 900 is recommended

Pos. Seq. Leakage (Prim-Star)	REAL	Constant	The positive-sequence mutual leakage inductance between the primary winding and the secondary star winding of the internal SVC transformer [pu]

Pos. seq. leakage (Prim-Delt)	REAL	Constant	The positive-sequence mutual leakage inductance between the primary winding and the secondary delta winding of the internal SVC transformer [pu]

Pos. seq. leakage (Star-Delt)	REAL	Constant	The positive-sequence mutual leakage inductance between the secondary star winding and the secondary delta winding of the internal SVC transformer [pu]

Total Inductive MVAR's of TCR	REAL	Constant	The 12-pulse maximum absorption limit of the SVC [MVAr]

Thyristor Snubber Resistance	REAL	Constant	The resistance of the thyristor snubber circuits. See Snubber Circuit for more details [W]

Thyristor Snubber Capacitance	REAL	Constant	The capacitance of the thyristor snubber circuits. See Snubber Circuit for more details [mF]

Thyristor ON Resistance	REAL	Constant	Resistance of all thyristors when in the ON state (conducting) [W]

Thyristor OFF Resistance	REAL	Constant	Resistance of all thyristors when in the OFF state [W]

Combined MVAR's of all Cap. Stages	REAL	Constant	The 12-pulse maximum production limit of the SVC. This value will be divided by the # of Capacitor Stages to determine the MVA rating of each TSC stage [MVAr]

Parallel Res. across Each Cap. Stage	REAL	Constant	The value of the parallel resistance across each capacitor stage. See Modeling of a Static VAR Compensator for more details [W]

Minimum Total Capacitive MVAR's	REAL	Constant	The minimum total capacitive MVAr [MVAr]

Rated Primary Voltage, L-L	REAL	Constant	The rated line-to-line voltage applied to the primary side of the SVC transformer [kV, RMS]

Primary Magnetizing Current	REAL	Constant	Magnetizing current used to calculate primary winding inductance [%]

Rated Secondary Voltage, L-L	REAL	Constant	The rated line-to-line voltage of the secondary side of the SVC transformer [kV, RMS]

Secondary Star Magnetizing Current	REAL	Constant	Magnetizing current used to calculate secondary star winding inductance [%]

Secondary Delta Magnetizing Current	REAL	Constant	Magnetizing current used to calculate secondary delta winding inductance [%]

Air Core Reactance	REAL	Constant	Saturated slope of the transformer reactance. This input is typically 0.3 - 0.4 [pu]

Inrush Decay Time Constant	REAL	Constant	Transformer inrush current decay time constant. Suggested value 0.2 to 1.0 [s]

Knee Voltage	REAL	Constant	Knee of the transformer saturation curve. This input is typically 1.0 - 1.2 [pu]

Shunt Loss Conductance	REAL	Constant	Hysterisis eddy current loss conductance to be placed at the SVC bus. 0.0 is acceptable [1/W]

Static VAR Compensator

Description

Input Parameters