Time-sharing control of multi-inverter-module parallel system for frequency multiplication

摘要

In order to fulfil the requirements in high-frequency and high-power applications, this paper presents a novel frequency multiplication method, in which N single-phase voltage-type inverter circuits are combined in parallel, being time-sharing controlled in rotation, and the output is through a transformer. The output frequency from the secondary side of the transformer will be increased to N times switching frequency. Using lower-frequency power switching devices for frequency multiplication, this scheme has several advantages. It overcome the limitation of dead-zone time of each inverter, possesses soft switching ability thus reducing the loss in switch tubes, and can be implemented at lower cost. This frequency multiplication method is analysed and simulated on a five-inverter-module system under ten different working conditions, with the associated parameters calculated. A five-module 800 kHz/20 kW prototype has been designed and the test results have shown the validity of the proposed method.