With Automatic Voltage Magnitude Control Patents (Class 363/164)
  • Patent number: 10504562
    Abstract: Disclosed is an improved load switch driver for power management integrated circuit (PMIC) devices. In one embodiment, a PMIC is disclosed comprising a gate driver, the gate driver connected to the gate of a switch; an operation frequency generator connected to the gate driver and configured to supply a periodic voltage to the gate driver; and a voltage sensor, the voltage sensor connected to the operation frequency generator and the source of the switch, the voltage sensor configured to monitor a drain-source voltage of the switch and lower the frequency of the operation frequency generator to a second frequency in response to detecting a collapse of the drain-source voltage.
    Type: Grant
    Filed: March 12, 2018
    Date of Patent: December 10, 2019
    Inventor: Matthew David Rowley
  • Patent number: 10411492
    Abstract: Techniques for focusing the energy radiated by a wireless power transmitting unit are described. An example power transmitting unit includes a transmitter coil configured to generate a magnetic field to wirelessly power a device within an active wireless charging area. The power transmitting unit also includes a power generating circuitry to deliver current to the transmitter coil to generate the magnetic field. The power transmitting unit also includes a shield disposed around the transmitter coil to reduce the strength of the magnetic field outside of the active wireless charging area.
    Type: Grant
    Filed: December 23, 2015
    Date of Patent: September 10, 2019
    Assignee: Intel Corporation
    Inventors: Zhen Yao, Songnan Yang, Suraj Sindia, Essam Elkhouly, Ntsanderh C. Azenui
  • Patent number: 9906077
    Abstract: A power transmission apparatus includes an inverter circuit, a power transmission antenna that wirelessly transmits alternating current power output from the inverter circuit, and a power transmission control circuit that causes the inverter circuit to output the alternating current power. The power transmission control circuit causes the inverter circuit to output the alternating current power as binary communication data by varying frequency of the alternating current power output from the inverter circuit between a first frequency and a second frequency, and performs amplitude control for eliminating a difference between amplitude of voltage of the alternating current power at a time when the frequency is the first frequency and amplitude of the voltage of the alternating current power at a time when the frequency is the second frequency.
    Type: Grant
    Filed: June 6, 2017
    Date of Patent: February 27, 2018
    Assignee: Panasonic Intellectual Property Management Co., Ltd.
    Inventors: Tsutomu Sakata, Hiroshi Kanno
  • Publication number: 20150009735
    Abstract: A method for transferring electrical power in the sea includes generating AC power, guiding, at least partially underwater, the AC power through a cable from a first end of the cable to a second end of the cable, and changing a frequency of the AC power guided through the cable based on a value of power consumption of a load connected to the second end of the cable.
    Type: Application
    Filed: July 2, 2014
    Publication date: January 8, 2015
    Inventors: Ove Boe, Espen Haugan
  • Patent number: 8830713
    Abstract: A method and apparatus are provided for operating a converter circuit, which includes n input phase connections and p output phase connections, where n?2 and p?2, and (n·p) two-pole switching cells for switching at least one positive and negative voltages between the poles. Power semiconductor switches of the switching cells are driven a drive signal. To reduce undesired circulating currents and adjust the mean voltage deviation of capacitive energy storage of all the switching cells to zero, an inductance is connected into each series connection, with a switching cell together with an inductance in each case forming a phase module. For each phase module, the drive signal is formed from a reference signal based on the voltage across the phase module and from a voltage signal across the inductance. The voltage signal is formed from an intermediate setpoint value of the current through the phase module.
    Type: Grant
    Filed: June 1, 2012
    Date of Patent: September 9, 2014
    Assignee: ABB Schweiz AG
    Inventor: Arthur Korn
  • Patent number: 8587239
    Abstract: Identification of electrical equivalent circuit parameters (15) of a three-phase asynchronous motor (09) without a shaft encoder. The method comprises—Assumption of a standstill position of the rotor (11);—Equidirectional test signal infeed U1?, U1? in ? and ? in the stator axis direction of the asynchronous motor (09);—Measuring of a measuring signal I1?, I1? of the ? and ? axial direction of the asynchronous motor (09); and—Identification of equivalent circuit parameters of the asynchronous motor (09) on the basis of the test signal voltages U1?, U1? and of the measuring signal currents I1?, I1?; whereby the test signal feed allows the rotor (11) to remain torque-free. Determination of equivalent circuit parameters (15) of an asynchronous motor (09) as well relates to a motor control device (35), whereby the identified equivalent circuit parameters (15) can be used for the determination, optimization and monitoring of a motor control and for control of electrical drives.
    Type: Grant
    Filed: August 9, 2011
    Date of Patent: November 19, 2013
    Assignee: Baumuller Nurnberg GmbH
    Inventors: Sebastian Villwock, Heiko Zatocil
  • Patent number: 8471407
    Abstract: An emergency power system for operation during loss of power on power mains comprises a spring-driven energy storage unit (ESU) and a generator. The ESU enters a generator mode responsive to a power outage state of a power sensor, during which mode unwinding of the spring drive powers the generator. After power is restored to the mains, a preferred embodiment automatically rewinds the spring using the generator as a motor.
    Type: Grant
    Filed: April 30, 2010
    Date of Patent: June 25, 2013
    Inventors: Thomas W. Gow, Edward L. Schwarz
  • Patent number: 8199545
    Abstract: A power-conversion control system includes an inverter, a cycloconverter, and a sliding mode controller. The inverter is operable to receive a DC voltage input and produce a first AC voltage output having a first frequency. The cycloconverter has a plurality of bidirectional switches, and is operable to receive the first AC voltage and to synthesize a second AC voltage having a second frequency that is lower than the first frequency. The sliding mode controller is operable to provide a control signal to command the plurality of bidirectional switches to turn OFF and ON when the first AC voltage is at a zero crossing condition. The sliding mode controller is also operable to selectively adjust the frequency and amplitude of the second AC voltage.
    Type: Grant
    Filed: May 5, 2009
    Date of Patent: June 12, 2012
    Assignee: Hamilton Sundstrand Corporation
    Inventors: Vietson M. Nguyen, Gregory I. Rozman, Sastry V. Vedula
  • Patent number: 8159851
    Abstract: A matrix converter includes a matrix converter main circuit, an input voltage detector group configured to detect an input voltage of an alternating current source, a gate driver configured to drive a bidirectional switch, and a controller having a pulse width modulation operation unit and a commutation operation unit. The pulse width modulation operation unit is configured to fix one output phase in a conduction state, configured to pulse-width-modulate one of remaining two output phases by using all three input phases, and configured to pulse-width-modulate the other output phase by using only two input phases of a reference input voltage and a middle input voltage.
    Type: Grant
    Filed: January 19, 2010
    Date of Patent: April 17, 2012
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Hidenori Hara, Eiji Yamamoto, Takahiro Uchino
  • Patent number: 8027173
    Abstract: An apparatus for providing an AC voltage includes a synthesizer for generating at least one periodic output voltage signal, each periodic output voltage signal having an output frequency. The synthesizer is supplied by an input AC voltage having an input frequency, and is configured such that each output frequency differs from the input frequency.
    Type: Grant
    Filed: July 30, 2008
    Date of Patent: September 27, 2011
    Inventors: Michael Baake, Michael Pavischitz
  • Patent number: 7821802
    Abstract: A power converter directly converting an AC voltage into an AC voltage of any desired magnitude and frequency by turning bidirectional switches ON and OFF without employing any energy buffer, where the peak values of output phase voltage command values are limited, to bring the amplitude of an output line voltage to, at most, 0.866 times the amplitude of the supply line voltages. By way of example, the peak-value limit of the output phase voltage command values is set so that the maximum value of the output phase voltage command values becomes, at most, 0.75 times the maximum value of supply phase voltages, while the minimum value thereof becomes, at least, 0.75 times the minimum value of the supply phase voltages. This control method for the direct power converter dispenses with an expensive dedicated motor, and permits a reduction in cost of the control apparatus as a whole.
    Type: Grant
    Filed: July 31, 2007
    Date of Patent: October 26, 2010
    Assignee: Fuji Electric Systems Co., Ltd.
    Inventors: Akihiro Odaka, Ikuya Sato, Yasuhiro Tamai
  • Publication number: 20100172168
    Abstract: The specification discloses a wireless power charging system in which undesired frequencies in the primary coil are cancelled. Exemplary undesired frequencies are the harmonics of the primary coil drive signal. The system includes a sense transformer/coil, an injection transformer/coil, and a compensation signal generator. The sense transformer/coil senses the signal in the primary coil. The compensation signal generator receives the sensed signal and generates an injection signal whose constituent parts are equal in amplitude to, but pi phase different from, each undesired frequency. The combined signal is injected into the primary through the injection transformer/coil so that the injection signal cancels the undesired frequencies in the primary coil.
    Type: Application
    Filed: May 27, 2008
    Publication date: July 8, 2010
    Inventor: Julian Andrew John Fells
  • Patent number: 7710063
    Abstract: An electric power converter, electric power conversion system and method that, without using a DC-DC converter, uses and allots the electric power of plural power sources while reducing the volume and losses. At least one phase of the motor is connected to plural power sources and generates and synthesizes pulses from output voltages of plural power sources so as to drive the multi-phase AC motor. A different phase of the motor is connected to one DC power source and generates pulses from the output voltage of the power source so as to generate a driving voltage for the multi-phase AC motor. This arrangement allows use/allotment of the power of plural power sources with a reduced number of semiconductor components.
    Type: Grant
    Filed: March 15, 2007
    Date of Patent: May 4, 2010
    Assignee: Nissan Moto Co., Ltd.
    Inventors: Kantaro Yoshimoto, Yasuhiko Kitajima, Kengo Maikawa
  • Patent number: 7626836
    Abstract: An apparatus and method for controlling an inverter, the apparatus including an adjustable frequency controller receiving a reference frequency value and generating a command frequency value as a function thereof, an adjustable voltage controller receiving a reference voltage value and generating a command voltage value as a function thereof and independent of the command frequency and a modulator receiving the command frequency value and the command voltage value and generating pulse width modulated (PWM) inverter control signals as a function thereof.
    Type: Grant
    Filed: October 26, 2005
    Date of Patent: December 1, 2009
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: David Leggate, Gary Leonard Skibinski, Gary R. Woltersdorf
  • Publication number: 20090257261
    Abstract: An output voltage command signal for outputting a specified three-phase ac output voltage is generated by a line voltage control command signal generating section, and a signal representing a current flow ratio is generated by a current flow ratio generating section based on a specified input current command signal. The output voltage command signal is corrected by a command signal computing section based on the output voltage command signal generated by the line voltage control command signal generating section and the signal representing the current flow ratio generated by the current flow ratio generating section. A PWM conversion signal is generated by a PWM conversion signal generating section based on the corrected output voltage command signal and a carrier signal. Based on the generated PWM conversion signal, a three-phase ac input voltage is converted into a specified three-phase ac input voltage by a conversion section.
    Type: Application
    Filed: April 20, 2007
    Publication date: October 15, 2009
    Inventor: Kenichi Sakakibara
  • Publication number: 20090052217
    Abstract: A method and an apparatus for damping voltage oscillation of a voltage intermediate circuit of a frequency converter, the frequency converter comprising a half controlled rectifier bridge coupled to a supply network. The method comprises determining magnitude (Uc) of voltage of the voltage intermediate circuit, determining magnitude (Uin) of rectified voltage of the supply network, forming a derivative of a difference (Uin?Uc) between the rectified voltage of the supply network and the voltage of the voltage intermediate circuit, delaying firing of controllable components of the rectifier bridge on the basis of the formed derivative.
    Type: Application
    Filed: August 18, 2008
    Publication date: February 26, 2009
    Applicant: ABB Oy
    Inventor: Markku TALJA
  • Patent number: 7339809
    Abstract: The present invention comprises systems and methods for electrical power regulation and distribution. In an embodiment, a system includes a modulator coupled to the source that receives an unregulated output waveform and is operable to produce a first composite waveform, and a mixing unit that is operable to generate a second composite waveform by introducing a frequency modulated component into the first composite waveform. A demodulator is coupled to the mixing unit that demodulates the second composite waveform to generate a third composite waveform. A filter network is coupled to the demodulator that is configured to select a desired spectral portion of the third composite waveform.
    Type: Grant
    Filed: November 30, 2004
    Date of Patent: March 4, 2008
    Assignee: The Boeing Company
    Inventors: David D. Bennett, Douglas S. York
  • Patent number: 7332882
    Abstract: A voltage detector is connected to a connection terminal connected to one phase of an AC output of an inverter through a diode. A removable charge power supply is connected to said connection terminal and another connection terminal. A charge-power-supply connection judging circuit judges whether the charge power supply is or isn't connected, based on a charge power supply voltage detected by a voltage detector. A mode change control circuit outputs switch signal by the result of said judgment. By receiving this switch signal, the inverter controller switches the operation of the inverter between the Motor Drive mode or the Battery Charge mode. Thereby, a motor drive device detects a connecting status of an external charge power supply and steadily switches the operation of the inverter between the Motor Drive mode or the Battery Charge mode.
    Type: Grant
    Filed: July 27, 2006
    Date of Patent: February 19, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Shigehisa Aoyagi, Tsunehiro Endo, Hidefumi Shirahama, Yoshiki Ito
  • Patent number: 7280938
    Abstract: The invention relates to a method for determining properties of a negative sequence component of a space vector quantity in an electrical network. The method according to the invention includes the steps of determining on the basis of the properties of an ellipse formed by a space vector of the space vector quantity in the electrical network the magnitude of the negative sequence component of the space vector quantity in the electrical network and the location of the negative sequence component of the space vector quantity in the electrical network in relation to a positive sequence component.
    Type: Grant
    Filed: March 11, 2004
    Date of Patent: October 9, 2007
    Assignee: ABB Oy
    Inventor: Antti Tarkiainen
  • Patent number: 7212421
    Abstract: A combination controller incorporates features of a classic controller and a state space controller to function as a hybrid controller unit. The PID portion of the classic controller regulates the steady state error and is separated from the pulse width modulated constant frequency signal generator that also comprises part of the classic controller. The PID portion is coupled with a state space controller such that the output of the PID controller, i.e., the steady state error correction, is input to the state space controller. The state space controller further receives as input variables a reference sinusoidal signal, the load current, the current across a pre-load filter capacitor, and the output voltage. From these inputs, the state space controller employs principles of differential calculus to generate a transient error correction that is fed to a PWM signal generator for generating a sinusoidal output voltage signal with both steady state and transient error correction.
    Type: Grant
    Filed: March 15, 2005
    Date of Patent: May 1, 2007
    Assignee: Perfect Electric Power, Inc.
    Inventors: Anuag Chandra, Suresh Gupta
  • Patent number: 6972976
    Abstract: The invention relates to a method for compensating for a voltage unbalance in an electrical network, which is fed by using an apparatus based on controlling a flux linkage vector or a voltage vector. Concerning the apparatus based on controlling the flux linkage vector, the method comprises the steps of determining a flux linkage reference vector comprising a positive sequence component and a negative sequence component, and controlling the feeding apparatus of the network in such a manner that the flux linkage vector thereof follows the reference vector with predetermined precision. The negative sequence component of the flux linkage reference vector is arranged to compensate for the amplitude and phase unbalance of the voltage in the electrical network to be fed.
    Type: Grant
    Filed: March 11, 2004
    Date of Patent: December 6, 2005
    Assignee: ABB Oy
    Inventors: Antti Tarkiainen, Mikko Vertanen
  • Patent number: 6760239
    Abstract: A method for controlling a matrix converter with nine bidirectional power switches arranged in a 3×3 switch matrix is described. Switching states of a modulation period are each calculated with associated time intervals by using a space vector modulation method. According to the invention, these calculated switching states are each divided into switching states of an output phase of the matrix converter, with time intervals assigned to the switching states, wherein the time intervals and the output-phase-related switching states are placed into one-to-one correspondence. Depending on the measured input voltages, the output-phase-related switching states with associated time intervals are combined into a pulse train of a modulation period, so that a sequential commutation always occurs to a nearest input voltage. This significantly reduces the switching losses of a matrix converter.
    Type: Grant
    Filed: May 15, 2003
    Date of Patent: July 6, 2004
    Assignee: Siemens Aktiengesellschaft
    Inventors: Hubert Schierling, Olaf Simon, Manfred Bruckmann
  • Patent number: 6343021
    Abstract: An electronic method and apparatus are described for an isolated, universal input, power supply in the form of a single-ended resonant converter that utilizes capacitive energy storage versus magnetic energy storage, for converting an ac or DC input voltage to a variable voltage and current DC output or a variable ac output voltage, current, frequency, or phase. The preferred topology is a direct ac to ac, single-ended resonant converter using a single switch (4) and integrated magnetic element (1) with inherent near-unity power factor. Advantages of this method include a significant reduction in global energy consumption, simpler circuitry, substantially lower cost, higher efficiency, and longer operational life.
    Type: Grant
    Filed: May 9, 2000
    Date of Patent: January 29, 2002
    Inventor: Floyd L. Williamson
  • Patent number: 6310901
    Abstract: A power supply is provided for use in a laser system including a gas ion laser tube which requires a filament voltage provided by an output section of the power supply. The filament voltage provided should not exceed a maximum AC filament voltage specified for the laser tube. The power supply is configured to receive AC utility power using one of at least first and second AC utility power sources having different first and second intended fixed magnitudes and which utility sources vary in amplitude from the intended fixed magnitudes over corresponding first and second source voltage ranges. The power supply is configured to include a power control arrangement which automatically controls the output section to generate an auto-ranging AC filament voltage from either of the first and second utility sources to be supplied as the filament voltage.
    Type: Grant
    Filed: May 6, 2000
    Date of Patent: October 30, 2001
    Assignee: JDS Uniphase Corporation
    Inventors: Mathew Mahmoudi, Warne M. Rintala
  • Patent number: 6018466
    Abstract: An electronic signal conditioner (ESC) (10) that can be designed to operate a differential capacitive load (90) or a single-ended capacitive load (92). The ESC (10) is disclosed in four design configurations. In the first design, the ESC (10) employs a pair of high-frequency transformers (34,48) each having a single-ended primary winding (36,50) that is connected through a secondary winding (42,56) to a rectifying circuit (70,80) that operates a differential capacitive load (90). The second design also employs a pair of transformers (32,34) that have push-pull primary windings (36,50) which similarly operate a differential capacitive load (90). The third design employs a single transformer (34) having a single-ended primary winding (36) which similarly operates a single-ended capacitive load (92). The fourth design also uses a single transformer (32) having a push-pull primary winding (36) which operates a single-ended capacitive load (92).
    Type: Grant
    Filed: August 4, 1997
    Date of Patent: January 25, 2000
    Inventor: Maria Lucian
  • Patent number: 5630155
    Abstract: An embodiment of the the present invention is a computer system comprised of a main computer circuit having an interruptible CPU, a control program stored in memory connected to the CPU with interrupt procedures, and a power supply that has a mainspring and winder, a generator, a regulator, a power supply, and an internal battery. The power supply is able to accept electrical power from the generator-regulator combination, house current (line voltage) through a standard outlet plug, and the battery. A user is able to input his own kinetic energy into the system by turning a winding key. The action is similar to winding up a large windup alarm clock. A pair of detectors connected to the mainspring sense when the mainspring is fully wound and when it is almost unwound. The unwound condition will interrupt the CPU and one of the interrupt procedures will bring the system to a controlled shut-down. The fully-wound condition will cause the system to be re-enabled to run normally.
    Type: Grant
    Filed: October 18, 1994
    Date of Patent: May 13, 1997
    Assignee: Seiko Epson Corporation
    Inventors: Nobuo Karaki, Osamu Miyazawa
  • Patent number: 5317500
    Abstract: An improvement in a control for a DC link power converter includes a phase command signal generator responsive to DC power on a DC link wherein the phase command signal generator develops a phase command signal for a control of the power converter whereby a parameter the DC power is caused to approach a certain level.
    Type: Grant
    Filed: August 6, 1992
    Date of Patent: May 31, 1994
    Assignee: Sundstrand Corporation
    Inventors: Steven M. Iden, Edwin J. Shires, Waleed Said
  • Patent number: 4905134
    Abstract: Prior variable speed constant frequency (VSCF) system controls which operate the VSCF system while it is coupled in parallel with an external AC source across a load have controlled inverter output voltage based only upon the reactive current level supplied by the inverter. This has in turn resulted in the possibility of unstable system operation under load. In order to overcome the foregoing problem, a control for controlling the supply of power to a load from an inverter coupled in parallel with an AC power source across the load senses the real and reactive components of the current supplied by the inverter and the phase displacement of the power developed by the inverter relative to the power developed by the AC power source to derive an angular displacement signal.
    Type: Grant
    Filed: December 29, 1988
    Date of Patent: February 27, 1990
    Assignee: Sundstrand Corporation
    Inventors: Bradley J. Recker, Christopher J. Rozman, Derrick I. Roe
  • Patent number: 4858100
    Abstract: An electric power converter, in which a plurality of converters convert a first electric power having a first frequency into a second electric power having a second frequency, and the second electric power is supplied to a load such as an electric motor, and in which a correction controller changes a reference voltage to generate reference voltage signals to be supplied to the converters in order to shift firing phase angles of the converters, thereby preventing a generation of higher harmonics of integer orders of the first electric power.
    Type: Grant
    Filed: March 29, 1988
    Date of Patent: August 15, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Shinji Tatara
  • Patent number: 4777581
    Abstract: The performance of the cycloconverter when used to drive an induction motor is at present limited because of inadequate methods of modulating the thyristor conduction angles. The main problems are: low maximum frequency due to subharmonics; voltage distortion due to discontinuous current and to uncertainty of current cross-over (for non-circulating current mode); and poor power factor on the input. This specification describes a modulation method which overcomes the first two of these problems without sacrificing performance in any area and proposes a new method to greatly improve the input power factor, although at the expense of possible input current subharmonics. A non-limiting application of the method to a 3 pulse, 3 phase, non-circulating current cycloconverter is described. The technique may also be applied to static power frequency changers other than the cycloconverter.
    Type: Grant
    Filed: April 20, 1987
    Date of Patent: October 11, 1988
    Inventor: Gregory P. Smith
  • Patent number: 4772994
    Abstract: A power source using high-frequency phase control possessing an ability to cause the transfer of electric power between a power source side and a load side to be made through a high-frequency transformer and to effect control of the output voltage by subjecting the power source side and the load side circuits to on-off control with a certain phase difference. This power source can be used as an uninterruptible power source, a device for controlled drive of a motor, a DC constant-voltage power source, or a constant-current device, for example.
    Type: Grant
    Filed: September 10, 1987
    Date of Patent: September 20, 1988
    Assignee: Nishimu Electronics Industries, Co., Ltd.
    Inventors: Koosuke Harada, Hiroshi Sakamoto, Masahito Shoyama
  • Patent number: 4764859
    Abstract: A current-circulating cycloconverter includes a positive converter and a negative converter connected in anti-parallel with each other through a DC reactor. A load is connected to an intermediate tap of the DC reactor. When a load current flowing to the load is smaller than a predetermined value, a circulating current flowing through the positive and negative converters is held at a minimum required value. A circulating current is caused to additively flow for canceling a voltage drop produced across the DC reactor when the load current exceeds the predetermined value.
    Type: Grant
    Filed: June 30, 1987
    Date of Patent: August 16, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Takayuki Matsui, Toshiaki Okuyama
  • Patent number: 4680695
    Abstract: A current regulator for a variable frequency power supply includes a proportional plus integral circuit that produces a composite control output signal for each phase. To improve the performance of the current regulator at higher frequencies, the composite control output signal for each phase also inlcudes a cross coupled component which is produced by multiplying a d.c. signal proportional to frequency times an integrator output signal from another phase. The composite control signals are applied to a voltage source inverter which produces the output currents to a load.
    Type: Grant
    Filed: October 27, 1986
    Date of Patent: July 14, 1987
    Assignee: Allen-Bradley Company
    Inventors: Russel J. Kerkman, Timothy M. Rowan
  • Patent number: 4675802
    Abstract: A 3-phase-to-3-phase power converter is intended to control the output voltage and current so as to provide a 3-phase sinusoidal wave which is controlled in compliance with the input voltage. The main circuit has a switching period shorter than 30.degree. of the power voltage waveform and it is controlled so that switching of lines takes place in alternate fashion, whereby the input power factor is improved.
    Type: Grant
    Filed: January 30, 1986
    Date of Patent: June 23, 1987
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Hidehiko Sugimoto
  • Patent number: 4658346
    Abstract: Apparatus for converting relatively high, variable frequency, variable amplitude electrical power into substantially constant amplitude and substantially constant, relatively lower frequency power of a preselected waveform. The power source signal is divided into a number of varying amplitude, same frequency segments. The segment having the amplitude nearest that of the preselected waveform is transmitted by a switching network during each of many time periods. The switching network is preferably controlled by a microprocessor that senses the amplitudes of the segments and compares them to the desired waveform amplitude as a function of time. The microprocessor provides control signals to the switching network in response to the comparison. Because the low frequency output signal is constructed with reference to a memorized signal, the output signal is particularly stable in spite of variations in the power source signal.
    Type: Grant
    Filed: December 11, 1985
    Date of Patent: April 14, 1987
    Assignee: Kennecott Corporation
    Inventor: Frederick E. Templeton
  • Patent number: 4648022
    Abstract: A three-pulse UFC system uses three groups of three bilateral switches controlled according to a switch polarity pattern to generate AC currents to a load, and a deadband hysteresis having upper and lower limits is used to maintain the load current so as to match a reference current.
    Type: Grant
    Filed: February 14, 1986
    Date of Patent: March 3, 1987
    Assignee: Westinghouse Electric Corp.
    Inventor: Colin D. Schauder
  • Patent number: 4639851
    Abstract: To eliminate thyristor failure due to voltage imbalance across series-connected thyristors during reverse voltage recovery caused by current discontinuity under continuous pulse application to the thyristors, the continuous pulse is discontinued after a time interval of application which is a function of the control signal establishing the firing delay angle. The continuous pulse is reinstated as in a double-pulse mode, thereafter, with the same controlled duration.
    Type: Grant
    Filed: April 25, 1985
    Date of Patent: January 27, 1987
    Assignee: Westinghouse Electric Corp.
    Inventor: Frederick O. Johnson
  • Patent number: 4590548
    Abstract: A direct a.c. supply converter for converting an N (.gtoreq.2) phase input voltage system into an a.c. output voltage system of different frequency, amplitude, and/or phase using width-modulated contributions from the phases of the input voltage system to produce the output voltage system suffers from the disadvantage that the maximum output voltage amplitude can be limited to the minimum instantaneous voltage of the input voltage system because of the arbitrary timing relationship between the two voltage systems. This limitation is relieved by the addition of a component at the N.sup.th harmonic of the input system frequency to the width-modulation so that the effective minimum instantaneous voltage of the input system is increased. An increase in the maximum output voltage amplitude can also be obtained by adding to the width-modulation a component at the P.sup.th harmonic of the output system frequency; this can be used along or in conjunction with the component at the N.sup.
    Type: Grant
    Filed: April 6, 1984
    Date of Patent: May 20, 1986
    Assignee: Texas Instruments Incorporated
    Inventor: Michael J. Maytum
  • Patent number: 4555755
    Abstract: In an AC current control system for controlling multi-phase AC currents supplied from a power converter to a load, the currents are detected and coordinate-transformed into orthogonal two-axis current values i.sub.d, i.sub.q in a rotating coordinate rotating at an angular frequency .omega., and then compared with the references. The deviations are used to determine two-axis voltage values e.sub.d *, e.sub.q *, which are coordinate-transformed into multi-phase voltage values determining the output voltages of the power converter. The system is characterized in that the voltage value e.sub.d * is determined not only from .DELTA.i.sub.d but also from the product of .omega. and .DELTA.i.sub.q, while the voltage value e.sub.q * is determined not only from .DELTA.i.sub.q but also from the product of .omega. and .DELTA.i.sub.d. This arrangement makes it possible to provide a voltage component corresponding to the voltage drop across the inductive component of the load which is 90.degree. in advance of the current.
    Type: Grant
    Filed: March 15, 1984
    Date of Patent: November 26, 1985
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Ryoichi Kurosawa, Takeo Shimamura
  • Patent number: 4538220
    Abstract: In an unrestricted frequency changer (UFC) the control pulses are generated by the intersection of a reference ramp of controllable slope and frequency with a succession of timing ramps characterizing the succession of phase voltages at the input of the UFC, whereby by increasing the slope and exceeding the peaks of the timing waves the sinusoidal shape of the output becomes trapezoidal and by increased slope increasingly close to a square-shaped wave, thus maximizing the output voltage at high frequency of operation.
    Type: Grant
    Filed: November 3, 1983
    Date of Patent: August 27, 1985
    Assignee: Westinghouse Electric Corp.
    Inventor: Laszlo Gyugyi
  • Patent number: 4510399
    Abstract: A demodulator circuit utilizes a switching demodulation technique to detect the real and reactive components of load current unbalance in a parallel source alternating current power system. A signal representing load current unbalance is selectively switched to a pair of output terminals in response to a series of pulse wave control signals which bear a phase relationship with the Thevenin equivalent voltage of one of the power sources such that the signal appearing at one of the output terminals represents the real load current component while the signal at the other output terminal represents the reactive load current component. The signals at these terminals are fed back to control the frequency and voltage magnitude of one of the power system sources to eliminate load current unbalance.
    Type: Grant
    Filed: October 7, 1982
    Date of Patent: April 9, 1985
    Assignee: Westinghouse Electric Corp.
    Inventor: Donal E. Baker
  • Patent number: 4480301
    Abstract: A system for forming addressing signals for addressing respective converter switches of a frequency converter; the frequency converter being of the type which is provided with DC input terminals for receiving electrical energy which is conducted to phase output terminals when the converter switches are operated in response to the addressing signals. Each of the combinations of converter switches is associated with a discrete space vector, and a load voltage vector is determined. In operation, two of the discrete space vectors which are adjacent to the voltage space vector are addressed for respective dwell times which correspond to the components of the voltage space vector as impressed upon the adjacent discrete space vectors. Either prior to or after the addressing of the adjacent discrete space vectors within a switching cycle, a short circuit state is addressed. In one embodiment, the order in which the adjacent discrete space vectors are addressed is reversed for each subsequent switching cycle.
    Type: Grant
    Filed: July 19, 1982
    Date of Patent: October 30, 1984
    Assignee: Siemens Aktiengesellschaft
    Inventors: Gerhard Pfaff, Albert Wick
  • Patent number: 4349867
    Abstract: A control apparatus for a cycloconverter includes m sets of bridge converters connected between the input terminals of an m-phase load (m.gtoreq.3) and is applied for a cycloconverter of which the common connection point of the bridge converters is disconnected from a neutral point of the load. The output voltage of each bridge converter is controlled by a reference voltage signal during a 1/m period of one cycle of the load voltage. The center of the 1/m period is located at a positive or negative maximum amplitude point of the load voltage. The output voltage is also controlled during the remaining period of (1-1/m) by a phase control input signal corresponding to a difference between a reference current signal and the load current. The reference voltage signal and the phase control input signal are selected by switching signals from a logic circuit for detecting phase voltages of the load to alternately be applied to the phase control circuits.
    Type: Grant
    Filed: March 6, 1981
    Date of Patent: September 14, 1982
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Kenichi Otsuka, Hiroshi Uchino, Kihei Nakajima
  • Patent number: 4225911
    Abstract: An apparatus and method for reducing the overvoltage transients present on the alternating current power signals provided by the cycloconverters of a variable speed constant frequency (VSCF) system during the first several cycles of the alternating current after a load reduction or no-load condition occurs. An overvoltage transient reduction circuit is connected to each of the plurality of D.C. control signals provided by the phase voltage regulators to the waveform generator of a conventional VSCF system. The overvoltage transient circuit and method of the present invention senses the current amplitude level in each of the alternating current power signals in the VSCF system, and automatically reduces the voltage amplitude levels of the D.C. control signals provided by the phase voltage regulators to a preselected lower level within one-half cycle of the alternating current after a load reduction occurs. This reduction in the amplitude level of the D.C.
    Type: Grant
    Filed: November 15, 1978
    Date of Patent: September 30, 1980
    Assignee: General Electric Company
    Inventor: Harold G. Carlson