Development considerations of DSP-controlled PWM VSC-based STATCOM

The paper addresses key issues surrounding the development of static VAr co mpensators (STATCOM). The STATCOM is based on a conventional six-switch bi- directional voltage-source convertor topology using insulated gate bipolar transistors. The sinusoidal pulse-width modulation technique is used to con trol the convertor output voltage (amplitude and phase), Three DC voltage c ontrol methods and the trade-off between the value of the DC capacitor and the ripple voltage and the system's transient response time are investigate d. The system's control. incorporating a VAr calculator and synchronisation , is implemented on a digital signal-processing board, to achieve excellent overall performance. Experimental results for both leading and lagging VAr compensation, along with changes between them, confirm the good performanc e and the flexibility of the developed prototype.