The novel strategy of restraining circulating currents in distributed-logical-control on parallel inverter system

Distributed-logic-control is an independent parallel inverter control technique. The strategy to restrain circulating currents based on distributed-logical-control is researched in the paper. The conventional method by power regulation to restrain the circulating current is affected by the parallel impedance and has such disadvantages in the response speed and harmonic component of circulating current. The strategy to restrain circulating current based on tracing transient average current feedback was proposed in the paper. Its impedance characteristic and the current sharing principle are analyzed. This strategy can reduce the system output impedance, while increase the impedance between parallel inverters. The novel strategy of restraining circulating currents is adopted by the combination of tracing transient average current feedback control and power adjusting strategy. The relevant experiments on the novel strategy were made in parallel inverter with distributed-logical-control, and the validity of the novel strategy was verified.