Abstract: The present invention includes an induction motor and a system for controlling the induction motor including a battery providing a DC voltage and an inverter coupled to the induction motor and the battery, wherein the inverter is adapted to drive the induction motor from the battery. A motor controller is adapted to calculate a flux current and a slip frequency in response to an induction motor speed. The motor controller is further adapted to operate in one of a current control mode or a slip control mode. The motor controller is adapted to cause the slip frequency to increase by a slip decremental in a transition phase from the current control mode to the slip control mode, and further adapted to cause the slip frequency to increase by a slip incremental in a transition phase from the slip control mode to the current control mode.

Abstract: An optical isolator for use in an electrically powered vehicle for interfacing between a signal processing system having a first ground and a power conversion system, which is operated responsive to control signals from the signal processing system, having a second ground that varies in potential from the first ground. A bi-directional digital communications network is provided having a first node coupled to the signal processing system for generating and receiving digital messages with respect to the first ground, and having a second node coupled to the power conversion system for receiving and generating digital messages with respect to the second ground. The bi-directional digital communications network has a unique start signal and a dominant hierarchy that allows bit-wise contention among messages for assuring communication of high priority messages between the first and second nodes within a predetermined minimum time period.