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| Number | Title | Issue Date |
| 7355307 | Rotary transformer for supplying electric power to a superconducting rotor A device for supplying electric energy to at least one superconductor, with the superconductor being cooled in a cooled region to at least one predetermined temperature for achieving superconductivity, includes at least one electric energy source, and a transformer ... | 04/08/2008 |
| 7262982 | Power conversion apparatus A power conversion apparatus is formed by connecting unit communication-assisting means in series between an alternating-current terminal incorporated in a conventional current-type power conversion apparatus, and an alternating-current load. The communication-assis... | 08/28/2007 |
| 7215098 | Electrical generating system having capacitative control of alternator regulation The invention provides an electrical generating system comprising an AC electrical generator (G) having an output, and a capacitor arrangement (Ca) provided at the output of the generator and arranged so as to offset a drop of voltage from no-load to full-load occur... | 05/08/2007 |
| 7193378 | Wye switch inverter for electric and hybrid vehicles A circuit for controlling a multi-phase machine having a stator with stator windings includes a controller, primary commutation switch pairs, a neutral terminal, and commutation control switches. Each switch pair includes first and second primary commutation switche... | 03/20/2007 |
| 7126833 | Auxiliary quasi-resonant dc tank electrical power converter An auxiliary quasi-resonant dc tank (AQRDCT) power converter with fast current charging, voltage balancing (or charging), and voltage clamping circuits is provided for achieving soft-switched power conversion. The present invention is an improvement of the invention... | 10/24/2006 |
| 7084609 | Alternator controlled rectifier A system and method for controlling the voltage output of an alternator is disclosed. The system includes an alternator having a rotor, which has a field winding, a stator having a plurality of phases, a rectifier bridge connected to the plurality of phases, at leas... | 08/01/2006 |
| 7061743 | Multi-pulse HVDC system using auxiliary circuit The present invention relates to a multi-pulse HVDC system which is capable of minimizing the number of thyristors by providing a thyristor auxiliary circuit in a conventional 12-pulse thyristor HVDC(High Voltage Direct Current), not using an additional stack of a t... | 06/13/2006 |
| 7015673 | Method and apparatus for reducing generated heat in three-phase motors driving air circulation fans in large industrial refrigerators and freezers A method and apparatus is disclosed for reducing the heat generated by three-phase motors operating under load in cooled chambers such as industrial walk-in refrigerators and freezers. Specific control elements are introduced into the three power conductors connecte... | 03/21/2006 |
| 7002123 | Microwave oven and method of controlling the same A microwave oven and a method of controlling the same. The microwave oven is capable of using a plurality of input powers with different frequencies. The microwave oven includes input power sources, an interrupt generation unit and a control unit. The interrupt gene... | 02/21/2006 |
| 6924991 | Energy transfer multiplexer An energy transfer multiplexer to control the flow of power or energy between an energy source and an energy load comprising a bi-directional inverter including a first bank or plurality of switches or first plurality of energy transfer control points and a second b... | 08/02/2005 |
| 6269010 | CSI based drive having feedforward control of inverter input voltage The drive for an a.c. induction motor features a rectifier for converting alternating current into direct current and a current source inverter for converting direct current into alternating current supplied to a motor. A d.c. link choke interconnects the... | 07/31/2001 |
| 6111770 | Auxiliary resonant DC tank converter An auxiliary resonant dc tank (ARDCT) converter is provided for achieving soft-switching in a power converter. An ARDCT circuit is coupled directly across a dc bus to the inverter to generate a resonant dc bus voltage, including upper and lower resonant c... | 08/29/2000 |
| 5892673 | Robust, high-density, high-efficiency state sequence controller for an auxiliary resonant commutation pole power converter A high-density control circuit for an auxiliary resonant commutation pole (ARCP) circuit is internal to the ARCP package and includes a state machine sequencer for providing control and timing signals to achieve high-efficiency, zero-voltage, and fault-to... | 04/06/1999 |
| 5880949 | Soft switching power converter comprising means for correcting the median voltage of a capacitive voltage divider A power converter comprises two main switches connecting an output either to the positive rail or to the negative rail. Two freewheel diodes for maintaining the current in the load, two snubbers and an auxiliary circuit including an auxiliary inductor in ... | 03/09/1999 |
| 5798916 | High power inverter pole employing series connected devices configured for reduced stray loop inductance A high power inverter pole for a voltage sourced inverter suitable for providing compensation in electric power transmission and distribution systems, has a positive switching valve and a negative switching valve connected between closely spaced dc-source... | 08/25/1998 |
| 5574636 | Zero-voltage-transition (ZVT) 3-phase PWM voltage link converters An improved zero voltage transition (ZVT) pulse width modulation (PWM) link converter is provided which introduces a space vector modulation scheme and an auxiliary circuit which includes a commutation power supply or special switch arrangement used to di... | 11/12/1996 |
| 5432695 | Zero-voltage-switched, three-phase PWM rectifier inverter circuit A novel switching rectifier circuit that combines the conventional three-phase, 6-stepped PWM rectifier/inverter circuit with a simple, low-power switch commutation circuit to provide zero-voltage turn-on for the switches, and soft turn-off for the diodes... | 07/11/1995 |
| 5331537 | Method of controlling electric valves of a converter Method of controlling electric valves of a converter using a universal algorithm for generating pilot signals (11) for multistage and multiphase line- and self-commutated converters (13, 14) is specified, by means of which it is possible to control differ... | 07/19/1994 |
| 5287260 | GTO rectifier and inverter A power converting apparatus controls switching of self turn-off type semiconductor devices so as to perform power conversion. The apparatus comprises a plurality of switch units each having first and second self turn-off type semiconductor devices, first... | 02/15/1994 |
| 5198972 | Turn-off switch phase control with improved ripple and power factor An improved commutation arrangement for an AC to AC or AC to DC energy converter circuit is disclosed. The improved arrangement uses turn-off capable commutation switches to enable modification of the operating waveforms in the cycloconverter. The modifie... | 03/30/1993 |
| 5187652 | Turn-off circuit In circuits with self-commutation such as, for example in inverters (4) for feeding an asynchronous machine (7), a short-time turn-off current impulse is taken from a turn-off capacitor (C1) of a turn-off or common turn-off circuit (3) for interrupting th... | 02/16/1993 |
| 5172309 | Auxiliary quasi-resonant dc link converter An auxiliary quasi-resonant dc link (AQRDCL) converter is employed to achieve soft-switching in an inverter coupled to a dc supply via a resonant dc link circuit. The resonant dc link circuit generates a quasi-resonant voltage to the inverter via a resona... | 12/15/1992 |
| 5084662 | Unipolar converter for variable reluctance machines The invention is a circuit (60) for controlling the operation of a variable reluctance machine having a plurality of phase windings. Pairs of phase windings (64, 66 or 65, 67) are controlled by a switching circuit having only three power switches which ar... | 01/28/1992 |
| 5053938 | Power converter having control circuitry for the voltage supplied to the inventer A converter of the electric energy fed by a unidirectional voltage source, comprising a voltage inverter circuit arranged to deliver an alternating voltage, possibly polyphase, to an inductive load such as an electric motor, wherein between the energy sou... | 10/01/1991 |
| 5047913 | Method for controlling a power converter using an auxiliary resonant commutation circuit A method for controlling a power converter and an associated auxiliary commutation circuit ensures soft-switching of all switching devices employed therein. Such a power converter includes an inverter with at least two main switching devices per phase. Ac... | 09/10/1991 |
| 4924370 | Low-loss and low-reactive power switching relief device for the semiconductor switches of an inverter A low-loss and low-reactive power switching relief circuit has an inverter output section coupled at its upper and lower ends to the positive or negative potential of a DC voltage source, respectively. The coupling is via saturable stepping choke coils. A... | 05/08/1990 |
| 4922401 | Inverter circuit utilizing the reverse voltage capabilities of symmetrical gate turn off thyristors A novel inverter circuit having symmetrical gate turnoff thyristors (GTO) includes reactive circuit elements for recovering stored energy. The circuit is characterized by a center tapped transformer configured without tightly coupled anti-parallel diodes,... | 05/01/1990 |
| 4908756 | Detecting apparatus for abnormality in inverter circuit A detecting apparatus for abnormality in an inverter circuit comprising an inverter circuit for converting electric power in a DC circuit into that in an AC circuit and vice versa based on a command signal for commutation, a detecting circuit for commutat... | 03/13/1990 |
| 4903188 | Pulse width modulated inductive load controller A pulse width modulated inductive load controller including a load switching circuit having a plurality of switches which are operative in pairs; each pair including first and second switch devices for controlling power to a load. Commutation logic enable... | 02/20/1990 |
| 4894762 | Method and apparatus to avoid commutation failure in a regenerative converter A method and apparatus to avoid commutation failure in a regenerative converter of a supply reversible converter of a voltage-source converter, in case of dynamic voltage depression. A firing control of the reversible converter is a function of the value ... | 01/16/1990 |
| 4847747 | Commutation circuit for load-commutated inverter induction motor drives 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.... | 07/11/1989 |
| 4833389 | Current source inverter control system for load commutated induction motor drive In a load commutated induction motor drive stability is achieved in a runaway situation by generating in response to the motor speed reference signal a signal representative of the desired power factor angle and in using such signal to delay by that much ... | 05/23/1989 |
| 4779034 | Forced commutation for variable speed motor A variable speed motor control system includes a power control circuit and a forced commutation control circuit for controlling the torque and rotational speed respectively of an induction motor. The power control circuit and the forced commutation contro... | 10/18/1988 |
| 4758939 | Converting apparatus and commutation control method therefor An improvement in a commutation control method or a control circuit for a converter comprising a plurality of converter units connected in cascade, which is provided with a circuit which maintains a phase control angle of each converter unit in an about c... | 07/19/1988 |
| 4752866 | Ozonator power supply employing a current source inverter A versatile current source inverter power supply for an ozonator in which a gating control circuit controls the gating of a thyristor bridge inverter power supply in a manner in which the output current to the ozonator is controlled and regulated. The cur... | 06/21/1988 |
| 4740881 | Simultaneous recovery commutation current source inverter for AC motors drives A simultaneous recovery commutation current source inverter is provided by connecting three AC output terminals of a main inverter and an auxiliary inverter in parallel with each other and to three terminals of an induction motor, providing a high AC impe... | 04/26/1988 |
| 4733146 | Energy recovery system for cyclic drives A system is disclosed for recovering and storing the energy generated by an electrical motor during deceleration so as to be available for use when the motor is subsequently accelerated. The system utilizes a capacitor for storing the energy produced by v... | 03/22/1988 |
| 4720776 | DC bus shorting apparatus and method for polyphase AC inverter An inverter for supplying electric alternating current (AC) to a load from a DC source of electric current has a DC bus. The DC bus has a positive conductor and a negative conductor. A plurality of switches are connected to the DC bus, and each of the swi... | 01/19/1988 |
| 4716515 | Switched capacitor induction motor drive A switched capacitor, induction motor drive circuit is provided wherein a switched capacitor in parallel with the inductive motor load at each output terminal is provided for commutation or switching of the main output inverter elements thereby protecting... | 12/29/1987 |
| 4713743 | Load-commutated inverter and synchronous motor drive embodying the same In a load commutated inverter system, the recovery time of the outgoing static switch is extended by applying an auxiliary commutation voltage in series with the associated phase line. This action is triggered in response to the gating signal of the on-co... | 12/15/1987 |
