| A closed-loop motor control system for a Segmented Electro-Magnetic Array permanent magnet brushless DC electric motor has been designed, constructed and tested. The control system is based on the TMS320F240 digital signal processor (DSP) from Texas Instruments and includes two TMS320F240-based DSP Evaluation Boards connected via a high-speed Serial Peripheral Interface (SPI) bus, Gate Driver Board, and Power Stage Board. One DSP board, called the Master Controller, performs commutation and phase current calculations. The second DSP board, called the Slave or Current Controller, is responsible for the current control. The Slave Controller compares the reference current value calculated by the Master Controller with the actual current in the stator coils and adjusts the duty cycle of a high frequency Pulse-Width Modulation (PWM) signal in order to make the stator current as close as possible to the reference current value. The PWM signal is sent to the Gate Driver board where it is conditioned to drive a power stage composed of a MOSFET H-bridge. |
