Abstrakt

Current Control Strategy for Parallel Operation of Inverters Based On Micro grids

M.Bavithra, Belwin J. Brearley

In this paper, a new control method for the parallel operation of inverters operating based on LV micro grids is proposed. This new approach can be applied to the inverter-based micro grids using renewable energy sources where communication wires are not reliable due to the remote locations. The proposed strategy is based on the advanced droop control technique where only the locally measured values are used as feedback. Unfortunately, the trade-off has to be made between the transient response and the power sharing accuracy for the conventional voltage and frequency droop control method. Moreover, the output and line impedance of the inverter presents a great impact on the power sharing accuracy. This paper explores the resistive output impedance and line impedance of the parallel connected inverters in island micro grid. The active and reactive output current is used as the control variables so as to limit the current spikes during the initial and transient states. Additionally, the derivate-integral terms are introduced to enhance the dynamic response of the inverters. Simulation results and waveforms are given to validate the proposed control strategy.