Improved multifunctional controller for power quality enhancement in grid integrated solar photovoltaic systems

Abstract

Purpose

This paper aims to propose an improved multifunctional control strategy for achieving real, reactive power flow control and the mitigation of power quality issues in grid integrated photovoltaic (GIPV) systems.

Design/methodology/approach

The paper proposes a dual stage, three phase, multifunctional GIPV system with modified instantaneous reactive power (IRP) theory-based and modified synchronous reference frame (SRF) theory-based control algorithms for reference template generation with continuous load power requirement tracking. The control structure is designed so as to impart virtual distribution static compensator functionality to the photovoltaic inverter. The dual mode operation in active filter and renewable power injection modes provides enhanced capability to the GIPV system. A comprehensive evaluation of the dynamic behaviour of the GIPV system is carried out for various conditions of irradiance and load under MATLAB/Simulink platform. The performance comparison is done considering an uncompensated system and the GIPV system with both proposed control algorithms.

Findings

The extensive simulation results demonstrate that the proposed modified SRF theory-based multifunctional control strategy shows superior performance in real and reactive power flow control; reduction in real and reactive burden of the utility grid; and regulation of dc bus voltage under varying scenarios of irradiance and load. Furthermore, there is improvement of grid power factor and reduction in total harmonic distortion of grid currents in compliance with the IEEE 519 standard even with highly non-linear loads at the point of common coupling.

Originality/value

The proposed modified SRF theory-based multifunctional controller offers a viable solution for power quality enhancement as well as the realization of effective real and reactive power flow control in GIPV systems. Thus, the penetration level of distributed generation can be increased in this era of global energy crisis.

Citation

Chacko, F.M., George, G.A., M.V., J. and A., P. (2020), "Improved multifunctional controller for power quality enhancement in grid integrated solar photovoltaic systems", World Journal of Engineering, Vol. 17 No. 4, pp. 585-598. https://doi.org/10.1108/WJE-12-2019-0356