Abstract: An electrical sub-assembly comprises a stator having a plurality of coils and a cooling means attached to the stator. The electrical sub-assembly further comprises a plurality of pairs of diodes attached to the cooling means, each pair of diodes being in antiparallel configuration and having three electrical terminals. One of the three electrical terminals is a common terminal shared by both diodes in each pair of diodes. A plurality of busbars electrically connect each of the diodes to at least one of the plurality of coils via one or more of the electrical terminals. In use, the cooling means is configured to simultaneously cool the stator and the plurality of diodes. The electrical sub-assembly may have particular application as a part of a switched reluctance machine.

Abstract: Motor drives and switch driver power systems are presented in which high frequency AC current (IHF) is provided through one or more cables (202) magnetically coupled with local driver current transformers (240), and the transformer secondary currents are converted to provide DC power to switch drivers of an active power converter stage (110a, 110b) in the motor drive.

Abstract: Power conversion systems with active front end converters for example motor drives and power generation systems for distributed energy sources are presented with adaptive harmonic minimization for grid-tie converters for minimized or reduced total harmonic distortion in the line current spectrum including the source harmonic current and the grid-tie converter injected current spectrum referred to the line side.

Abstract: A motor drive and a choke therefor are disclosed, wherein the choke comprises a magnetic core with an inner leg and two outer legs, and four coils, which may be connected in DC current paths in the motor drive. First and second differential coils are wound around first and second outer legs, respectively; and first and second common-mode coils are wound around the inner leg of the choke. The first and second differential coils smooth the DC current on a DC bus in the motor drive, and the first and second common-mode coils suppress common-mode voltages in the motor drive. Also disclosed is a method for suppressing common-mode voltages in a motor drive.

Abstract: The present invention provides an apparatus for controlling power factor compensation and method thereof, in which a turn-on timing point of a power factor compensation switch is delayed by a prescribed time from a zero crossing timing point to enhance a power factor. The present invention includes periodically detecting a zero crossing time point of an inputted voltage, turning on the power factor compensation switch if a turn-on time point of the power factor compensation switch set to a time point delayed by a prescribed time from the detected zero crossing time of the inputted voltage is reached, and turning off the power factor compensation switch if a prescribed time passes after turning on the power factor compensation switch.

Abstract: In a load commutated inverter induction motor drive a parallel capacitor bank is used in part to force-commutate the thyristors of the inverter as triggered by auxiliary thyristors and turned off by the other part of the capacitor bank.

Abstract: A motor speed control circuit in which a source of alternating current (AC), a universal-type motor, a triac and a large capacitor are connected in series, with the armature current flowing through the large capacitor and with the control providing armature-current sensing and feedback action for each half cycle of motor operation for stabilizing motor speed at any speed setting in spite of changes in the torque load being imposed on the motor. A triggering circuit for the triac includes a diac connected on one side to the control electrode of the triac and on the other side to an RC network across the portion of the series circuit containing the large capacitor and the triac. The RC network includes a variable resistor for adjusting the speed of the motor by setting the phase of the signal to the triggering diac. Power is supplied to the motor during both positive and negative half cycles of the AC supply voltage.

Abstract: D.C. motor control utilizing an input transformer with magnetic leakage and current control to allow power, whether generated occasionally or continuously from the motor (induced by load inertia and the like) to be smoothly returned back into the main A.C. power line, consistent with continuous smooth speed control (low form factor), low heating and low cost.

Abstract: A turn off circuit for a multiphase motor is provided, comprising a D.C. powered system including a three element choke core having two outer cores with loosely coupled windings and a central core closely coupled to the outer cores to enhance pulse generation.A modified SCR ring counter is provided to supply D.C. power to the load to produce a three phase wave shape with less wave distortion and lower noise.Pulse width modulation is supplied to the negative SCRs of the ring counter through steering SCRs which are turned on by discharge from capacitors in the steering circuit.Pulse width modulation is fed to the ring counter through the outer core elements, while the central core functions to improve pulse width of the discharge capacitors. Free wheeling energy from the motor is fed to the discharge capacitors and increases firing energy.

Abstract: A turn off circuit for a multiphase motor is provided comprising a DC powered system including a three element core having a central core element and an inner and outer core element coupled thereto.A series of capacitors are connected to an outer core element to discharge simultaneously and turn off positively and negatively biased SCRs which sequentially fire and produce a suitable pulse width and frequency to the motor.A control system is provided to produce a variable pulse frequency and pulse width to a power circuit which sequentially fires and admits battery power to the motor.

Abstract: A turn off circuit for a multiphase motor is provided comprising a DC powered system including a three element core having a control core element and an inner and outer core element coupled thereto.A series of capacitors are coupled to the central core winding to produce suitably shaped pulses to turn off positively and negatively biased SCRs which control power switching SCRs.A control system is provided to produce a variable pulse frequency and pulse width to a power circuit which sequentially fires and admits the battery power to the motor.