An improved SRF based control algorithm for D-STATCOM under abnormal source voltage

This paper describes an improved SRF (Synchronous Reference Frame) based control technique or algorithm for time varying power flow control and optimum load compensation of non-linear loading under abnormal or disturbed source voltage by D-STATCOM designed for three-phase three wire systems. The improved algorithm is based on the active power separation and imaginary symmetrical components of voltage and has been compared with conventional IRP based algorithm to show the preciseness in finding the reference current for a DSTATCOM under abnormal i.e. asymmetric and distorted source voltage. Individually the algorithms were implemented and simulated under MATLAB/Simulink. The simulation results also show which algorithm can accurately detect the harmonics and reactive component of load current even under the asymmetric and distorted source voltage condition. Additionally by the control loop of reactive power of improved algorithm, load reactive power can be compensated as well as regulated under variations of load. Thus this additional control arrangement can help system operators improve overall system performances.