Enhancement of large renewable distributed generation penetration levels at the point of common coupling

Abstract

The occurrence of distortion and over voltage at the Point of Common Coupling (PCC) of Renewable Distributed Generation (RDG) limits its penetration levels to the power system and the RDG integration is expected to play a crucial role in power system transformation. For its penetrations to be sustained without disconnection from the system, there must be a solution to the voltage rise, distortion, unbalanced current and grid reactive power control strategy at PCC. It is an IEEE-1547 requirement that RDG integration to the power system should be regulated at PCC to avoid disconnection from the network due to power quality criteria. RDG integration must meet up with this specification to uphold power quality and avoid damage to the sensitive equipment connected at PCC. In this paper, voltage rise, unbalanced current, reactive power and distortion are being managed at PCC while Distribution Network (DN) accepts more RDG penetration levels without violation of the IEEE and South Africa grid code act. Active Power Filter and Full Bridge Multi-Level Converter (FBMC) are considered to safeguard power quality to the grid, they are modelled in MATLAB/SIMULINK and the results obtained shown that the proposed strategy can successfully regulate voltage rise, distortion, unbalanced current and continuously improve power quality with RDG integration at PCC. The proposed method’s key innovation is the strategic generation and absorption of reactive power to curtain an overvoltage, reverse power flow, and distortion at the PCC, allowing more RDG penetration levels to the grid without disconnection while maintaining the standard requirement for power quality at the PCC. The simulation outcomes validate the superiority of the FBMC over the active power filter with respect of reactive power generation/absorption, dynamic response, and damping capability.