Position-sensing by ZCP Filter for 3-Phase Sinusoidal BLDC Motor Controller

Abstract

In this thesis, studied is a ZCP (Zero Crossing Point) filter scheme along with slow start-up initial driving method for sensor-less 3-phase sinusoidal BLDC (Brush-Less DC Motor) controller. ZCP filter is a key IP block to detect the rotor position of the BLDC motor and control the driving transistors of an inverter. A traditional 3-phase sinusoidal BLDC motor uses 3 hall sensors to detect the rotor position to control the motor speed. In this case, hall sensors are installed inside a BLDC motor. But it often causes reliability problem in automotive applications due to malfunction of the sensor. Therefore, sensor-less BLDC motor becomes more desirable and the position detection scheme replacing the hall sensor is key area of research. The proposed digital ZCP filter for the rotor position detection alone with a slow start-up initial driving is implemented by digital logic designed by using Verilog HDL. Also, SPWM (Sinusoidal Pulse Width Modulation) sensor-less BLDC motor controller is designed by Verilog HDL. All function is implemented and verified by using a FPGA.