Switched reluctance starter/generator control system allowing operation

Abstract

An electric power generating system comprises a switched reluctance machine, an inverter having a dc input/output coupled to a dc bus, switches responsive to switching control signals for coupling each of the machine's phase windings to the dc bus, and diodes for cross-coupling each of the phase windings to the dc bus. A controller having a number of control inputs and outputs coupled to the inverter monitors the current flowing in the phase windings and the voltage level on the dc bus, and calculates a maximum and a minimum phase current control signal. The controller modulates the switching control signals to regulate the phase current within a range defined by these control signals to maintain the voltage level at a desired level. Upon calculating a positive phase current control signal, the controller generates switching control signals to enable switches at a fixed angle prior to alignment, and generates switching control signals to disable the switches at a fixed angle after alignment. In this way, the machine generates sufficient electric power to maintain the voltage level at the desired level. Upon calculating a negative phase current control signal, the controller generates switching control signals to enable the switches at a fixed angle prior to alignment, and generates switching control signals to disable one switch at a fixed angle prior to alignment. In this way, the machine dissipates sufficient electric power to maintain the voltage at the desired level.