Considerations of DSP controlled VSC based STATCOM

The paper presents the analysis of the PWM static VAr compensator (STATCOM) when the pole assignment control method is used in order to improve the dynamic response. The STATCOM is based on a conventional six-switch bi-directional voltage source converter topology using insulated gate bipolar transistors (IGBTs). The sinusoidal pulse width modulation technique is used to control the converter output voltage (amplitude and phase). Two references DC voltage for DC voltage control are using and the trade-off between the value of the DC capacitor and the ripple voltage and the system´s transient response time are investigated. The control system, has incorporated VAr calculator and synchronization, which, together the control algorithm, has been implemented on a digital signal processing (DSP) board, to achieve excellent overall performance. Experimental results for both leading and lagging VAr compensation, along with changes between them, confirm the good performance and the flexibility of the developed prototype.