Modeling, simulation and implementation of four-switch, Brushless DC motor drive based on switching functions

This paper proposes a macro-model to simulate of four-switch, three-phase inverter (FSTPI) brushless DC (BLDC) motor drive using switching functions. The proposed model uses inverter switching functions instead of actual circuits, and capable to show the whole steady state and transient performance of the drive. An entire BLDC motor drive including power conversion unit, BLDC motor, current and speed control system, is investigated. The proposed model is exact and easy for implementation and is implemented with the help of Matlab-Simulink software. Using this concept, it is possible to show he detailed electrical variables, such as phase current, line and phase voltages and diode and switch currents. Due to problems caused of eliminating two power switches, direct phase current (DPC) control method is carried out. Proposed model is demonstrated via simulation as well as experiment.