Enhanced Operation of Grid-Connected Inverter to Improve Power Quality Issues, Harmonic Compensation with the Proposed Novel Approach

Abstract

AbstractIncrease in power electronic devices/ equipment causes serious power quality concern. Furthermore, the wide use of unbalanced and non-linear loads is responsible for line harmonics and significantly deteriorates power supply quality. Increase penetration of renewable sources injects harmonics into the utility grid. Thus, power quality is a significant issue that requires focus while integrating renewable sources into the grid. The main objective of this paper is to study power management between grid, renewable sources and linear/non-linear loads. Additionally, a simple current controller is proposed which enables the voltage source converter to realize as a shunt active filter. This proposed controller is fixed in voltage source inverter with predefined active and reactive power reference so as to improve grid power quality with reduced THD percentage under unbalanced/non-linear connected at the point of common coupling. This controller is utilized in the outer loop of VSC, where reference currents are generated based on the grid voltage and current with prespecified active and reactive power. Reference signals are then compared with tracked grid side Id and Iq and obtained error is transferred to PI controller for zero steady-state error regulation. Enhanced SRF-PLL is used to generate grid synchronization angle, which is utilized into natural a-b-c to synchronous d-q transformation. The MATLAB/Simulink verifies the capability of the proposed controller.KeywordsCurrent controlPoint of common coupling (PCC)Proportional integral (PI) controllerRenewable energy sources (RES)Power quality (PQ)Voltage source converter (VSC)