A local enhanced Var/Watt control scheme for overvoltage mitigation in PV-integrated distribution network

Abstract

Overvoltage (OV) in distribution networks (DNs) poses a significant challenge to the high penetration of photovoltaic systems (PVSs). Utilizing the active/reactive power control capabilities of PVSs (PV-ARPC) is a well-established method for OV prevention. Among PV-ARPC schemes, local schemes are the most reliable and cost-effective solutions, offering high plug-and-play capabilities. Conversely, non-local schemes provide superior performance with reduced PV-ARPC effort. This creates a research gap in developing a local PV-ARPC scheme that matches the optimal performance of non-local schemes. To address this gap, this paper introduces an enhanced local optimal PVS active power curtailment (PV-APC) scheme that autonomously identifies the most efficient PVSs and determines the optimal PV-APC value without requiring communication. Additionally, an enhanced PVS reactive power control (PV-RPC) scheme is integrated to maximize OV mitigation benefits while minimizing the need for PV-APC. The functionality and optimal performance of the proposed schemes are validated through contradiction proof, stability analysis, and various comparative time-domain simulations under diverse operating conditions. The proposed method achieves a 15 % reduction in PV-APC compared to existing local droop-based methods during peak generation, maintaining all bus voltages within allowable limits while also achieving active power curtailment levels equal to non-local fully-optimal schemes.