Extending Operational Range for Low-Cost Motor Drive Systems by Mitigating Narrow Pulse Effect

In this paper, a method to mitigate narrow pulse effect for extending operational range of low-cost motor drive system, where the bootstrap circuit is embedded, is described. Because of the narrow pulse effect, dead zone appears in output of the inverter where voltage cannot be synthesized. To overcome the narrow pulse effect, the proposed method combines the inverter nonlinearity compensation and dead time elimination (DTE) method. By mixing those two properly, the narrow pulse effect can be reduced effectively and the output capability of the inverter increases conspicuously. Simulations and experiments are carried out to verify the effectiveness of the proposed method. The experimental results reveal 6 % enhancement of torque capability at two times of base speed.