Sensorless control of an four switch three phase inverter using FPGA

The main objective of this paper is to achieve low cost BLDC driver by the reduction of switch device, cost down of control, and saving of hall and current sensors. In this paper, a simple position sensor less control strategy for four-switch three-phase BLDC motor drives using closed loop PWM controller technique and FPGA (Field Programmable Gate Array) is proposed. Four-switch inverter can reduce cost of drivers by replacing power devices with capacitors. This work designs four-switch inverter for three phase BLDC motor. The position sensor less BLDC drive proposed is based on detection of back electromotive force (back EMF) zero crossing from the terminal voltages.