Method and apparatus for determining phase current of switched reluctance electric machines

Abstract

A method for determining phase current for each of a plurality of individual phase coils of a switched reluctance machine (SRM) is disclosed. In an exemplary embodiment, the method includes determining the current passing through a first resistive element and a second resistive element in an SRM drive circuit. A conduction mode of the SRM drive circuit is determined, the conduction mode being based upon an ON/OFF state of each of a pair of switching transistors controlling current through each of the plurality of individual phase coils. The phase current through each of the plurality of individual phase coils is then calculated, based upon the conduction mode and the determined current passing through said first and second resistive elements.

1 . A method for determining phase current for an individual phase coil of a switched reluctance machine (SRM), the method comprising: 
 determining a first bus current passing through a first resistive element in an SRM drive circuit;    determining a second bus current passing through a second resistive element within said SRM drive circuit;    determining a conduction mode, K, of said SRM drive circuit, by summing one or more weighted values corresponding to an ON/OFF state of each of a pair of switching transistors controlling current through said individual phase coil; and    calculating the phase current through said individual phase coil based upon said conduction mode and said first bus current and second bus current passing through said first and second resistive elements by applying a specific set of current equations dependent upon K.