ANALYSIS OF DSTATCOM WITH DIFFERENT CONTROL ALGORITHM UNDER DISTORTED AND UNDISTORTED SOURCE VOLTAGE

Abstract

This dissertation deals with MATLAB simulation analysis of Some Advance Control Algorithms in DSTATCOM. Power quality of distribution systems is influenced by different events in the real time operation of the utilities supply network. It is important to identify these factors and develop remedies for their reduction or removal. In this dissertation, main contribution is to implement some of intelligent control algorithms for DSTATCOM (Distribution Static Compensator) to enhance its operational flexibility, robustness, tracking capability, accuracy, dynamic response etc. according to the requirements. In the present work three control algorithms are implemented for control of a DSTATCOM for elimination of harmonics in supply current, improvement of power factor & reactive power compensation. These are IRP (Instantaneous Reactive Power) theory, SRF (Synchronous reference frame) theory, Unit Template control algorithm. These control algorithms are based on mathematical calculations and on some improved features of previous conventional algorithms. The operation of a DSTATCOM is demonstrated for mitigation of harmonics in source current due to non-linear loads of various types on supply system. The operation of DSTATCOM is also demonstrated in mitigation of harmonics in supply current due to distortion in source voltage. Because supply current is affected due to both distortion in source voltage and nonlinear load These algorithms use two closed loop PI controllers mainly for regulating supply side AC voltage magnitude and DC link capacitor voltage. The control algorithm generates reference supply current for providing PWM signals through PWM controller. Pulse width modulation or hysteresis current controller is used for generation of PWM gating pulses of IGBT’s in the VSI. The proposed algorithms are simulated in MATLAB/SIMULINK in different operating conditions. Results simulation are presented and discussed for harmonic elimination and power factor correction at the AC supply terminals.