A novel parallel inverter system based on coupled inductors

The difference of amplitude and phase between each module´s output voltage can cause large loop-current among modules in parallel inverter system. Individual inductor connected between the inverter´s output terminal and the load can restrain loop-current well with the disadvantage of reducing steady-state voltage accuracy of parallel system. Aiming at this problem, this paper proposes a novel coupled inductor-based parallel inverter system in which coupled inductors is used to restrain loop-current. Design principle of coupled inductors in parallel inverter system with two or more modules is also presented. Simulation and experimental results in a two-module 6 kVA parallel inverter system prove that coupled inductors-based parallel inverter system has many advantages such as smaller loop-current and higher steady-state voltage accuracy than parallel system based on individual inductor.