Three-Phase Single-Stage VSC Controlled Solar Photovoltaic System with Harmonic Filtering Capability Applied to DG

Abstract

This paper presents a single-stage three-phase four-wire (3P4W) grid-connected solar photovoltaic (SPV) system controlled with a unit vector template (UVT) based approach. The key advantage of the presented control approach is that it takes less computational time compared to its conventional counterpart. In this approach, the SPV system is uniquely controlled to operate as a multifunctional inverter by incorporating harmonic filtering capability. The SPV system with presented control can, therefore, be utilized i) as multifunctional inverter to inject the active power generated from SPV system to the utility grid, and ii) as active power filter (APF) with harmonic filtering capability to acquire various features including source current harmonic attenuation, load reactive current compensation, source currents balancing, in addition to, power factor correction (PFC). Since the SPV system is based on the UVT-based approach, it accurately estimates the reference currents for the voltage-sourced converter (VSC). The 3P4W topology is utilized in this paper in order to confront the neutral current issue in the power distribution network, as this topology has inherent neutral current mitigation capability. A perturb and observe (P&O) based tracker is employed to identify and track the maximum power point (MPP). The practicality of SPV system with presented control is tested and elucidated using MATLAB/Simulink simulation studies. Finally, the proposed VSC controlled SPV system is validated through a comprehensive set of experimental studies on laboratory developed prototype.