In this paper, a high frequency, interleaved, dual-buck, bidirectional, grid-connected converter topology is proposed. Free from the straight-through and dead-time distortion issues, both higher switching frequency and power density can be achieved. Due to the interleaved technique, the current ripple and stress for inductors and other power devices can be effectively reduced. Moreover, a novel filter parameter design method is proposed. The method is optimized with smaller inductance, higher filtering performance, and better steady-state performance. For one thing, the performance requirements under the two states of inverter and rectifier are comprehensively considered. For another, the relationship between the performance indexes and the filter parameters is analyzed. However, the results show that the relationship between the performance indexes is contradictory. A set of optimization parameters were obtained by setting the priority of the filter performance index. The specific design process of the filter parameters is given in detail. In order to verify the rationality of the parameter design, a 5 kW prototype was built and tested. The total harmonic distortions (THDs) of the grid currents in the among grid-connected inverter, off-connected inverter, and rectifier states under full load were 2.7%, 1.2%, and 4.5%, respectively, and the power density reached 36 W/in3.
An Optimized Parameter Design Method for Passivity-Based Control in a LCL-Filtered Grid-Connected Inverter
