Abstract: A motor system having a stationary assembly including a winding and a rotatable assembly in magnetic coupling relation to the stationary assembly. A power supply link having upper and lower rails supplied by a power supply provides power to the motor winding. The power supply link has power switches responsive to a motor control signal for selectively connecting the rails to the winding to energize the winding with a motor current whereby an electromagnetic field is produced for rotating the rotatable assembly. The power switches include a set of upper power switches and a set of lower power switches. Each of the power switches has a conducting state and a nonconducting state. The system includes a disable circuit for selectively generating a disable signal and a control circuit for generating the motor control signal to control the power switches.

Abstract: A torque shudder protection device for an induction machine includes a flux command generator for supplying a steady state flux command and a torque shudder detector for supplying a status including a negative status to indicate a lack of torque shudder and a positive status to indicate a presence of torque shudder. A flux adapter uses the steady state flux command and the status to supply a present flux command identical to the steady state flux command for a negative status and different from the steady state flux command for a positive status. A limiter can receive the present flux command, prevent the present flux command from exceeding a predetermined maximum flux command magnitude, and supply the present flux command to a field oriented controller.

Abstract: A current regulator for a four-legged, three-phase inverter determines the next optimal, or near-optimal, inverter state in a relatively short time period based on phase current error signals and back-emf's, resulting in low harmonic distortion, reduced current ripple, minimal current stresses, and increased utilization of the available dc bus voltage over a high bandwidth.

Abstract: A microcomputer-based drive system for a switched reluctance motor requires no rotor position sensor and no discrete current sensors. Phase excitation is synchronized with rotor position by indirectly estimating rotor position according to instantaneous phase inductance. Current regulation is achieved by incorporating pilot devices for current sensing into the switching devices of the power converter and by employing a fixed off-time current chopping strategy. One application is for use in a laundering machine.

Abstract: A polyphase AC motor drive system comprises an electric power inverter and control means which enables operation in, and allows smooth transition between, a current controlled PWM mode and a quasi-square wave mode of operation. At low motor speeds, the system operates in PWM mode. At higher speeds, above the corner point speed of the motor, the system operates in a quasi-square wave mode. Smooth transitions between modes of operation are controlled by a microcomputer which counts the number of current chops made by a switching device in a preselected phase leg of the inverter over a time interval that varies with the desired fundamental period of the motor current. As speed increases and approaches the corner point, the number of chops decreases below a first predetermined number, and the system transitions from PWM to quasi-square wave mode. As speed decreases, the number of chops increases above a second predetermined number (larger than the first), and the system transitions back to PWM mode.

Abstract: A commutator for a microcomputer based switched reluctance drive employs a selectively addressable non-volatile memory, e.g. a ROM, to store stator phase firing patterns and facilities selective adjustment of turn-on angle and pulsewidth of phase switching current pulses. Firing patterns differing only in pulsewidth of their respective pulses can be stored in different sections of the memory or in the same section where word bit width permits. The adjustment of pulse position and duration allows torque control of the motor over a very wide speed range.

Abstract: A start-up control for a switched reluctance motor employs an encloder for generating a rotor position information signal for each stator phase and a start-up signal processor. The processor receives the rotor position information signals and processes them in accordance with a direction command. To initiate forward rotation, the information signals are complemented; to initiate reverse rotation, the information signals for adjacent phases are AND-coupled.