Analysis and design optimization of brushless DC motor´s driving circuit considering the Cdv/dt induced effect

Considering the main parasitic parameters in brushless DC (BLDC) motor´s driving circuit of “three phase bridge” topology, the switching characteristics under high frequency and large current circumstances are analyzed. Firstly, the switching operation process of the BLDC motor´s driving circuit is presented. In particular, the Cdv/dt induced effect which is caused by main parasitic parameters of the circuit is analyzed in detail. Secondly, an equivalent circuit of one bridge leg is presented in modeling, and then the analytical solutions of the circuit´s differential equations are derived. Based on the model, the simulations are performed to study the Cdv/dt induced effect with different values of main parasitic parameters. Finally, several design optimizations of BLDC motor´s driving circuit are presented, and a practical prototype is used to validate the proposed approach.