Patent ID: 6078161
Filing Date: 2000-06-20
Classification: H02P

Abstract:
A current controlling apparatus of a switched reluctance motor (SRM) having an inverter unit for variably switching the excitation state of each phase of a polyphase stator, comprising:a position sensing unit for sensing the relative position of a rotor to the polyphase stator which varies as said rotor is rotated, by a resolution of a predetermined angle;a current command unit for conveying a current command through a switching pulse for supplying a current corresponding to the position of said rotor to an armature coil which binds said stator;a current sensing unit which is electrically connected to said inverter unit and senses the current which is actually applied to the armature coil;a digital to analog conversion unit for generating a direct-current (DC) controlling voltage by performing a digital to analog conversion after receiving the switching pulse from said current command unit;a current controlling unit which generates a current controlling signal so that a current error between the current command conveyed from said current command unit and the current which is actually applied can be compensated, after receiving the outputs of said digital to analog conversion unit and said current sensing unit; anda pulse width modulation unit which drives the SRM by performing a pulse width modulation after receiving the current controlling signal outputted from said current controlling unit and then supplying it to said inverter unit,wherein said digital to analog conversion unit comprises:a first low-frequency filtering unit which performs the digital to analog conversion through low-frequency filtering of output of said current command unit; anda second low-frequency filtering unit which performs the low-frequency filtering/smoothing of output of said first low-frequency filtering unit.