DSTATCOM Using Limit Cycle Oscillator FLL with Optimized Gains of Voltage Error Controllers

Abstract

In this paper, an algorithm depending on limit cycle oscillator-based frequency-locked loop is used to extract fundamental component of load current. The extracted fundamental components are used to control distribution static compensator (DSTATCOM). The major function of DSTATCOM is to make source current sinusoidal for compensation of power quality problems. This reduces the reactive burden on the source and helps in making source current sinusoidal. The reference grid current has been produced by extracting fundamental components from each phase of load current using limit cycle oscillator (LCO)-based frequency-locked loop (FLL). An optimization algorithm named multi-verse optimization (MVO) which is based on population has been used for estimation of PI gains as error controller in various modes of operation of DSTATCOM as mentioned. The error minimization of DC bus voltage and terminal voltage has been formulated as an unconstrained optimization problem, and gains have been estimated. To maximize the benefits of the MVO optimization process, the local search accuracy has been improved. This improvement has been achieved by increasing the wormholes in the universe. The suggested control scheme with gain values from the MVO optimization technique has controlled issues like reactive power compensation and mitigation of grid current harmonics caused due to an identified harmonic producing load, i.e. a three-phase AC voltage controller with resistive loads. This work provides results of d-SPACE-based realization of the suggested limit cycle oscillator-based frequency-locked loop algorithm for DSTATCOM.