PROJECT TITLE :

An Accurate Power-sharing Control Method Based on Circulating-current Power Phasor Model in Voltage-source-inverter Parallel-operation System - 2017

ABSTRACT:

This paper proposes an optimized mathematical model of the voltage-supply inverter parallel-operation system (VSIPS) and proposes an improved droop management methodology based on this model, which can realize accurate power sharing in VSIPS. First, this paper analyzes VSIPS as a multi-input and multioutput system and proposes a certain definition of circulating current. The circulating-current model, the steady-state model, and the little-signal model are proposed subsequently based on the optimum design of wire impedance, that constitute the optimized mathematical model of VSIPS in s-domain. The circulating-current phasor model and the circulating-current power phasor model (CCPPM) are proposed. Second, the mathematical model of traditional droop control is made and analyzed based mostly on CCPPM, which elaborates the tradeoff of droop control between the steady-state voltage bias and therefore the load-sharing accuracy, and proves that the V - Q droop management cannot understand accurate reactive-power sharing. Third, an improved droop control technique (? - Pcir and V - Qcir control) is proposed, which will notice the correct activeand reactive-power sharing and eliminate the steady-state voltage bias simultaneously. Finally, simulation and experimental results are presented, which validate the proposed mathematical model of VSIPS, the analysis of droop control, and also the performance of the proposed technique.