Voltage Profile Enhancement Using Capacitor-less D-STATCOM to Increase PV Integration in Distribution Network Under Transient Cloud Conditions

Abstract

Over the past decade, the emergence of Distributed Energy Resources (DERs) has significantly disrupted the traditional approach of having centralized plants that distribute electricity through an extensive transmission and distribution network. Given the proliferation of DERs in recent years, more importantly, the rise of grid-connected distributed photovoltaic (PV) systems and the implementation of the smart-grid concept, the electric utility industry of today is in the midst of an aggressive expansion and an unprecedented evolution. The stochastic nature of PV output has created new challenges in electric distribution systems' operation and maintenance. Of particular significance is the direct correlation between the PV power output and rapid voltage fluctuations. Reactive power compensation can be used to regulate the voltage profile on the network within the allowable limits set by the relevant standards. A capacitor-less distribution static synchronous compensator (D-STATCOM), based on a matrix converter (MC), is proposed to be used in low-voltage distribution networks. This technology is controlled using finite-set model predictive control (MPC); the compensator device can operate in various modes and can be deployed as needed in the low-voltage distribution network. Simulation results is presented to show the proposed technology's effectiveness in improving voltage profile in low-voltage distribution networks under transient cloud conditions.