ENHANCEMENT OF POWER QUALITY DISTRIBUTION SYSTEM USING FPID IN D-- STATCOM

Abstract

This paper presents the enhancement of voltage sags, harmonic distortion and low power factor using Distribution Static Compensator (D-STATCOM) with LCL Passive Filter in distribution system. This model is based on the Voltage Source Converter (VSC) principle. The D-STATCOM injects a current into the system to mitigate voltage sags. LCL Passive Filter was then added to D-STATCOM to improve harmonic distortion and low power factor. The simulations were performed using MATLAB SIMULINK version R2007b.A new PWM-based control scheme has been implemented to control the electric values in the D-STATCOM. The D-STATCOM has an additional capability to sustain reactive current at low voltage and can be developed as a voltage and frequency support by replacing capacitors. Voltage sag is a short time event during which a reduction in rms voltage magnitude occurs. Voltage sags are improved with insertion of D-STATCOM. When the value of fault resistance is increased, the voltage sags will also increase for different types of faults. Suitable adjustment of the phase and magnitude of the D-STATCOM output voltages allows effective control of active and reactive power exchanges between D-STATCOM and AC system. The PI controller will process the error signal to zero. The load rms voltage is brought back to the reference voltage by comparing the reference voltage with rms voltages that had been measured at the load point. It also used to control the flow of reactive power from the DC capacitor storage circuit. The PWM generator can produce the desired synchronizing signal the is required. PWM generator also receives the error signal angle from PI controller. The modulated signal is compared against a triangle signal in order to generate the switching signals for VSC values. To enhance the performance of distribution system D-STATCOM was connected to the distribution system. D-STATCOM was designed using MATLAB SIMULINK version R2007b.