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Model Static Var Compensator Using Thyristor-Switched Capacitor and Thyristor-Controlled Reactor

Since R2024a
Open Model

This example models a static var compensator (SVC) using thyristor-switched capacitors (TSC) and a thyristor-controlled reactor (TCR).

Model Overview

The SVC comprises two TSC and one TCR. Initially, two 400 MW loads and a 300 MW load connect to the primary and secondary side of the substation transformer. The grid voltage is 1 per unit. One TSC is in service and the SVC controller regulates the firing angles to the TCR so that the sum of the reactive power that the TSC generates is equal to the reactive power that the TCR absorbs.

At a simulation time of 0.5 s, the connection to the secondary side of a 450 MW load causes the grid voltage to drop below 0.96 per unit. The SVC starts to supply reactive power by switching in the other TSC and by controlling the TCR. As a result, the grid voltage increases to 0.986 per unit.

At a simulation time of 1 s, a 400 MW load and the 450 MW load disconnect from the primary and secondary side, respectively. This load disconnection causes the grid voltage to rise above 1.05 per unit. The SVC starts to absorb reactive power by switching out two TSC and by controlling the TCR. As a result, the grid voltage decreases back to 1.006 per unit.

Model Different Levels of Details Using Variant Controls

Use the StaticVarCompensatorParameters script to create variant controls for the static var compensator and the controller. Specifically, the script defines these Simulink.Variant objects:

  • TSCTCR_SVC and DynamicLoad_SVC - Use these objects with the thyristor-based SVC and dynamic load based SVC.

  • Controller_TSCTCR, Controller_DynaimcLoadTimeMode, and Controller_DynaimcLoadFrequencyAndTimeMode - Use these objects with the time and frequency-and-time simulation mode.

This script also defines a fidelity variable that specifies the level of fidelity.

This example supports three different levels of fidelity:

  • Low - The example runs in frequency-and-time simulation mode. A dynamic load models the SVC. The sampling time is equal to 1/60 s.

  • Medium - The example runs in time simulation mode. A dynamic load models the SVC. The sampling time is equal to 100 us.

  • High - The example runs in time simulation mode. Thyristor-switched capacitors (TSC) and a thyristor-controlled reactor (TCR) model the SVC. The sampling time is equal to 50 us.

You can change the level of fidelity in the StaticVarCompensatorVariantControl script. This script configures the sampling time and simulation mode accordingly.

Plot Simulation Results from Simscape Logging

These plots show the voltage magnitude at the substation transformer primary side and reactive power that flows into the AC grid.

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