This paper proposed a novel predictive variable structure- switching-based current controller for a three-phase load driven by a power inverter. The design specifications are robustness to load electrical parameters, fast dynamic response, reduced switching frequency, and simple hardware implementation. In order to meet previous specifications, a sliding mode controller has been developed, which is designed as finite-state automata, and implemented with a field-programmable gate array (FPGA) device. The switching strategy implemented within the state transition diagram provides for a minimum number of switches by the three-phase inverter that is confirmed through simulation and experimental results. Its regulation using the proposed control law provides good transient response by the brushless ac motor control. However, this does not limit the wider applicability of the proposed controller that is suitable for different types of ac loads (rectifier and inverter) and acmotors (induction, synchronous, and reluctance). A new logical FPGA torque and speed controller is developed, analyzed, and experimentally verified.
1. Brushless alternating-current (BLAC) motor
2. field-programmable gate array (FPGA)
3. finite-state machine (FSM)
4. predictive control
5. sliding mode controller (SMC)
Fig.1. Basic Circuit Of A VSI.
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