Research on 180° conduction of brushless dc motor driven by high frequency link inverter

Brushless DC motor in 180° conduction operation may occur the phenomenon the same leg short, in order to solve this problem, the traditional non-isolated three-phase inverter is replaced, and the high-frequency link matrix inverter is studied for driving brushless DC motor 180° conduction operation. In this paper, the non-isolated three-phase inverter is replaced for the brushless DC motor in the 180° conduction operation. Based on the decoupling idea, an HPWM modulation strategy for brushless DC motor load is used. There is 30 electrical angle difference between the brushless DC motor 180° conduction switch drive signal and the hall signal, and the hall signal can be directly logic synthesis of the minimum signal width of 60 electrical angle, so 180° conduction switch the driving signal can not be directly synthesized by the hall signal, based on this the first three times the frequency of the hall signal and then double the frequency of the switch drive signal synthesis method is proposed. The working mode of the inverter in a sector is analyzed in detail, due to the switch opening and shut off, the energy passing through the transformer between power supply and motor winding, and the synthesis method of 180° conduction drive signal is described. The correctness of the method is verified on the basis of experiment.