Abstract:
This paper proposes a new simple control technique using FPGA for controlling the variable speed switched reluctance drive. The phase currents in the low speed zones are controlled by hysteresis chopping method for which the reference current is generated by PI controller. The turn-on angle is kept fixed in current control. Angle control method is used in the high speeds zones, in which, turn-on angles are obtained by using a separate PI controller rather than generally used lookup table method. The turn-off angles are made to decrease with increase in speed using a generalized equation for both low and high speeds. Boundary issues are discussed in detail to find the suitable border line between chopping and angle control. This new control strategy is not only easy to implement but it reduces complexity, solves boundary problems and reduces time and efforts required for computation of angles as compared to look up table approach. Simulation and experimental results are presented for a 2.2 KW machine to validate the proposed control strategy. FPGA based controller is used for implementing the control technique.