Three-bridge buck inverter

On the basis of dual-buck half-bridge inverter, a three-bridge buck inverter is proposed, which not only remains the advantages of dual-buck half-bridge inverter, but also improves the inverter's performance such as avoids shoot-through problem, removes the reverse recovery losses of body diodes and so on. By adding a new bridge, the three-level modulation and the single power supply are realised, which increase the DC voltage utilisation rate. In addition, smaller volume and weight of the system and higher system integration can be achieved using only one filter inductor compared with other dual-buck-type inverters. The unipolar sinusoidal pulse width modulation scheme is adopted in the inverter system, so the switching frequency is fixed, which is beneficial to the design of filter. The operating principle and characteristics of the proposed inverter are analysed in detail. A 1 kW prototype is established and tested, and the results of simulation and experiment verify the good performance of the proposed inverter.