Patent ID: 7880428
Filing Date: 2011-02-01
Classification: H02P

Abstract:
1. A controller for an induction motor comprising: a storage device which stores values in a plurality of addresses; a first phase first counter configured to transit circularly among first to N-th states; a first phase second counter configured to transit circularly among first to fourth states; a calculating section configured to calculate first calculation values; and a signal generation section configured to generate first pulse width modulation (PWM) signals for controlling an inverter and synchronous interruption signals at constant time pitch such that pulse widths of said first PWM signals are adjusted based on said first calculation values respectively, wherein said inverter supplies first electric power to an induction motor based on said first PWM signals, said first phase first counter transits from one to next of said first to N-th states synchronously to each of said synchronous interruption signals, said first phase second counter transits from one to next of said first to fourth states synchronously to each transition of said first phase first counter from said N-th state to said first state, and said calculating section, synchronously to each of said synchronous interruption signals, calculates one of said first calculation values based on said first phase first counter and said first phase second counter from one of said values stored in one of said plurality of addresses.