Parallel operation control of N+1 redundant inverter system

In this paper, a novel parallel operation algorithm of N+1 redundant inverter system with no control interconnections for loas-sharing is presented. The proposed control system eliminates the sensing noise and interconnection interface of conventional parallel operation system. To reduce a reactive power deviation in wireless control method, this technique automatically compensates for inverter parameter variation and line impedance imbalances with wireless auto-tuning method. In addition, to increase reliability on transient characteristics of parallel operation, a virtual injected impedance is adopted to eliminate a circulation current among inverter modules. Simulation results are provided in this paper to prove the proposed novel algorithm.