Generation of possible switching patterns for VSI using microcontroller for the control of PM BLDC motor

It has been observed that adoption of different possible switching patterns/schemes affects the transient behaviours such as phase current and torque of a PMBLDC motor. Four possible switching patterns are achieved by modulating only upper/lower switches and incoming/outgoing phase switches. For the purpose of control of PMBLDC motor low cost ATMEGA 32 micro-controller is used to generate all the four possible switching schemes. Use of dummy hall sensor is a near ideal and cheaper approach to prepare micro-controller for the control of PMBLDC motor. Dummy Hall sensor signals where generated for variable speed reference with the help of micro-controller to analyse inverter voltages. Provision is made to bypass the generated dummy hall sensor signal with actual hall sensor signal from the motor for the control purposes.