CONTROL ANALYSIS OF STATCOM UNDER POWER SYSTEM FAULTS

Abstract

Voltage source convertors based static synchronous compensators are used in the transmission and distribution line for voltage regulation and reactive power compensation. Nowadays angle controlled STATCOM have been deployed in the utilities to improve the output voltage waveform quality with lower losses compared to that of PWM STATCOMS. Even though angle control STATCOM has lot of advantages, it suffers in their operation, when unbalanced and fault conditions occur in the transmission and distribution lines. This paper presents an approach of Dual Angle control strategy in STATCOM to overcome the drawbacks of the conventional angle control and PWM controlled STATCOMS. Here, this paper will not completely changes the design of conventional angle control STATCOM, instead it add only (αac ) AC oscillations to the output of the conventional angle controller output (αdc) to make it as a dual angle controlled. Hence the STATCOM is called dual angle controlled (DAC) STATCOM.