Device and method for controlling a time variable inductive load

摘要

A switched reluctance machine controller derives an error signal from the difference between a current reference and the phase winding current. The error signal is applied to a pair of hysteresis circuits which define adjacent hysteresis bands above and below the reference current. The magnitude of the hysteresis bands may vary as a function of the current reference. The outputs of the hysteresis circuits are received by control logic which permits current to be applied to the phase winding when the current is below the hysteresis bands, removes current from the phase winding when the current is above the hysteresis bands and allows the phase winding current to freewheel when the current is between the upper and lower hysteresis limits. The power device used for freewheeling alternates between an upper power device and a lower power device.