STATCOM (STATic COMpensator)


 This example presents a FACTS (Flexible Alternative Current Transmission Systems) based on a three-level VSI (Voltage Source Inverter) working as a Static Var Compensator (SVC).

The goal of such a system is to provide reactive power to a high voltage transmission line in order to keep its voltage level to a specified value.

The advantage of the three-level VSI is the reduction of its output current harmonics without increasing the switching frequency of the valves (Thyristors GTO or IGCT, Integrated Gate Control Thyristor).


 To achieve such performance, an efficient regulation part has been implemented.

It contains a PLL (Phase Locked Loop), a special control with high modulation index, a reduced switching frequency of the valves with high frequency carrier signal and a PWM (Pulse Width Modulation) control.


 SIMSEN is able to take into account the real topology of a FACTS device with all the semiconductors.

This provides to the user a detailed analysis of the system. The ON-LINE FFT (Fast Fourier Transform) has been applied to the transformer line current.

Its results have been successfully compared with the harmonics analysis.


 The user can implement and investigate several control methods in order to compare them.

Once the VSI has been successfully implemented and checked, the studied system may be extended with network elements (machines, transmission lines, transformers, a.s.o) to investigate more in details the behavior of FACTS devices in a high voltage AC network.