Abstract: An apparatus for generating electromagnetic torque in an N-phase electric machine, N being a positive integer, includes N lines, each of the N lines including an input terminal, an output terminal, and a pair of thyristors, or of one thyristor and one diode pair. The N lines are connected between a mains and the electric machine. An apparatus is provided for repeatedly or continuously determining at least the sign of a voltage over the thyristor or diode-thyristor pair in at least one of the N lines, means are provided for repeatedly or continuously determining at least one parameter related to the electromagnetic field in the electric machine, and a control device is provided for controlling the operation of the thyristor or diode-thyristor pair of the at least one of the N lines.

Abstract: An apparatus for generating electromagnetic torque in an N-phase electric machine, N being a positive integer, includes N lines, each of the N lines including an input terminal, an output terminal, and a pair of thyristors, or of one thyristor and one diode pair. The N lines are connected between a mains and the electric machine. An apparatus is provided for repeatedly or continuously determining at least the sign of a voltage over the thyristor or diode-thyristor pair in at least one of the N lines, means are provided for repeatedly or continuously determining at least one parameter related to the electromagnetic field in the electric machine, and a control device is provided for controlling the operation of the thyristor or diode-thyristor pair of the at least one of the N lines.

Abstract: A washing machine is provided that includes an induction motor and a motor control circuit with a feedback loop. The feedback loop provides rotor speed to a microprocessor of the motor control circuit. The motor control circuit and feedback loop control the motor such that the motor operates in a reverse frequency mode which provides braking to the washing machine.

Abstract: A novel architecture of high-power four-quadrant hybrid power modules based on high-current trench gate IGBTs and arrays of low-current wide-bandgap diodes is conceived. The distributed physical layout of high power density wide-bandgap devices improves the cooling inside a fully-sealed module case, thus avoiding excessive internal heat flux build up and high PN junction temperature, and benefiting the converter's reliability and efficiency. The design of multiple-in-one hybrid integrated AC-switch module at high power ratings is enabled by using hybrid AC switch cells and aluminum nitride substrate structure.

Abstract: An electric drive apparatus and method for controlling medium-voltage alternating current motors wherein a multi-phase power transformer having multiple secondary windings provides multi-phase power to multiple power cells which provide four quadrant operation. Each power cell has a single-phase output and is controllable by a modulation controller. The power cells are connected in series thus permitting the maximum output voltage for each cell to be less than the maximum line-to-line voltage. Each power cell can have a rectifier portion to convert input AC-to-DC, capacitors, an output DC-to-AC inverter, a regenerative bridge converter connected in parallel with the rectifier portion and a local modulation controller connected to a master controller.

Abstract: The invention relates to a method of ensuring the stability of a synchronous machine in controlling the synchronous machine on the basis of direct control of flux and torque, in which the torque generated by the synchronous machine is increased/decreased by increasing/decreasing the instantaneous angular velocity of the stator flux. In accordance with the invention, the method comprises the steps of determining the direction of the stator flux vector (.psi.s) in rotor coordinates (dq), and forcing the stator flux vector (.psi.s) to remain in quadrants I and IV (Q1, Q4) of the rotor coordinates by rotating the stator flux in the rotor coordinates to a necessary degree.

Abstract: A level detector outputs signals every time voltages induced by the U-phase, V-phase and W-phase motor coils exceed a predetermined level. When the signals are output in a predetermined order from the level detector, U-phase, V-phase and W-phase commutation circuits supply control signals to U-phase, V-phase and W-phase drive current output circuits, respectively. When the signal outputting order is reversed to the predetermined order, the commutation circuits output no control signals. Upon reception of the control signals from the U-phase, V-phase and W-phase commutation circuits, the U-phase, V-phase and W-phase drive current output circuits supply the currents to the respective motor coils. When at three-phase half-wave motor is rotating in the forward direction, therefore, the currents will be sequentially supplied to the motor coils from the associated drive current output circuits for the individual phases.

Abstract: A constant voltage voltage-source inverter of a motor drive includes in its DC-link the combination of diode means, a GTO device and an auxiliary thyristor, the GTO device and the auxiliary thyristor upon transferring to the regenerating mode being cyclically controlled for conduction concurrently with the thyristor of the AC/DC converter so as to match the (voltage-current) domains converter and input of the inverter. Conduction of the GTO device is interrupted before each cyclical control thereof to allow recovery.Initiation of GTO and auxiliary thyristor conduction upon mode transfer is retarded to allow settling of the system before firing the thyristors of the AC/DC converter with a different firing angle.

Abstract: A control system for a commutatorless motor comprises a frequency converter which includes two graetz-connected thyristor converters and D.C. lines interconnecting the converters, between an A.C. motor and an A.C. power supply. Motoring operation and regenerating operation are selectively effected between the motor and the power supply. In switching the operation mode, one of the converters which has been operated in a recitifier operation mode is first switched to an inverter operation mode, and after it has been confirmed that a control voltage to determine a firing angle of the one converter has been shifted to an inverter region, the other convertor is switched to the rectifier operation mode.