Patents by Inventor Lizhi Zhu

Lizhi Zhu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 8125806
    Abstract: A multi-stage power supply uses a boost stage and an inverter stage to boost the voltage value of a DC power supply to a desired level, and then convert the power into an AC form. The multi-stage power supply additionally has a controller which can simultaneously control the boost stage and the inverter stage using counter-synchronous signals.
    Type: Grant
    Filed: January 26, 2009
    Date of Patent: February 28, 2012
    Assignee: Continental Automotive Systems US, Inc.
    Inventors: Kirk Nangreaves, Charles-Lizhi Zhu, Richard Joseph Hampo
  • Patent number: 7983013
    Abstract: A circuit and method to provide dynamic fault protection to transistors are disclosed. The fault protection may be particularly suited for protecting insulated gate bipolar transistors (IGBTs).
    Type: Grant
    Filed: November 29, 2007
    Date of Patent: July 19, 2011
    Assignee: Continantal Automotive Systems US, Inc.
    Inventors: Fengtai Huang, Bryan Ludwig, Fred Flett, Subramanian S. Vadula, Lizhi Zhu, Richard J. Hampo
  • Publication number: 20100322284
    Abstract: A method for determining power semiconductor operating temperatures uses a database of measured temperatures. Each temperature is associated with operating conditions and determined by laboratory testing in an environment indicative of operation of the power semiconductors actual operations.
    Type: Application
    Filed: April 26, 2010
    Publication date: December 23, 2010
    Applicant: CONTINENTAL AUTOMOTIVE SYSTEMS US, INC.
    Inventors: Charles Lizhi Zhu, Ajay V. Patwardhan, Fred Flett, Matthew R. Obrigkeit
  • Patent number: 7800921
    Abstract: Power converter system topologies comprise a DC/DC converter. The DC/DC converter includes a transformer coupling a high side to a low side. The high side may include an inverter bridge in the form of an inverter module and an inductor. The low side may include a rectifier in the form of a rectifier module and a pair of inductors. The transformer may take the form of a planar transformer.
    Type: Grant
    Filed: January 8, 2008
    Date of Patent: September 21, 2010
    Assignee: Continental Automotive Systems US, Inc.
    Inventors: Lizhi Zhu, Fred Flett, John M. Van Dyke
  • Publication number: 20090190380
    Abstract: A multi-stage power supply uses a boost stage and an inverter stage to boost the voltage value of a DC power supply to a desired level, and then convert the power into an AC form. The multi-stage power supply additionally has a controller which can simultaneously control the boost stage and the inverter stage using counter-synchronous signals.
    Type: Application
    Filed: January 26, 2009
    Publication date: July 30, 2009
    Inventors: Kirk Nangreaves, Charles-Lizhi Zhu, Richard Joseph Hampo
  • Publication number: 20090067109
    Abstract: A circuit and method to provide dynamic fault protection to transistors are disclosed. The fault protection may be particularly suited for protecting insulated gate bipolar transistors (IGBTs).
    Type: Application
    Filed: November 29, 2007
    Publication date: March 12, 2009
    Applicant: SIEMENS VDO AUTOMOTIVE CORPORATION
    Inventors: Fengtai Huang, Bryan Ludwig, Fred Flett, Subramanian S. Vadula, Lizhi Zhu, Richard J. Hampo
  • Patent number: 7456602
    Abstract: A system and method for controlling power converters are disclosed. Briefly described, one embodiment is a method comprising communicating at least one first control signal to an alternating current/direct current (AC/DC) power converter from a multi-converter system controller, the AC/DC power converter and the multi-converter system controller residing in a power system electronics housing, and communicating at least one second control signal to a direct current/direct current (DC/DC) power converter from the multi-converter system controller, the DC/DC power converter residing in a power system electronics housing.
    Type: Grant
    Filed: November 18, 2005
    Date of Patent: November 25, 2008
    Assignee: Continental Automotive Systems US, Inc.
    Inventors: Richard J. Hampo, John M. Van Dyke, Lizhi Zhu, Sayeed Ahmed
  • Patent number: 7449259
    Abstract: A fuel cell based power supply comprises a main power converter and control that allows the fuel cell stack to be electrically shorted from time-to-time to improve performance. Additionally, the power converter may temporarily disconnect the fuel cell stack from the load after shorting, allowing the fuel cell stack to return to an open circuit voltage, and/or provide current limiting during a period after shorting to provide stable operation while the fuel cell stack powers the load and recharges a power storage device.
    Type: Grant
    Filed: September 4, 2003
    Date of Patent: November 11, 2008
    Assignee: NuCellSys GmbH
    Inventors: Lizhi Zhu, Richard J. Hampo, Brian W. Wells
  • Publication number: 20080205089
    Abstract: Power converter system topologies comprise a DC/DC converter. The DC/DC converter includes a transformer coupling a high side to a low side. The high side may include an inverter bridge in the form of an inverter module and an inductor. The low side may include a rectifier in the form of a rectifier module and a pair of inductors. The transformer may take the form of a planar transformer.
    Type: Application
    Filed: January 8, 2008
    Publication date: August 28, 2008
    Applicant: CONTINENTAL AUTOMOTIVE US, INC.
    Inventors: Lizhi Zhu, Fred Flett, John M. Van Dyke
  • Patent number: 7362557
    Abstract: A controller implements a state machine for operating the bi-directional power converter with a flexible load pattern while maintaining a thermal condition of the power converter within acceptable limits. The state machine implements a wait loop in response to selected conditions to maintain the thermal condition.
    Type: Grant
    Filed: March 30, 2005
    Date of Patent: April 22, 2008
    Assignee: Continental Automotive Systems U.S. Inc.
    Inventors: Christophe Soudier, Lizhi Zhu, Vinod Reddy, Venkatapathi R. Nallapa
  • Patent number: 7295448
    Abstract: A power converter architecture interleaves full bridge converters to alleviate thermal management problems in high current applications, and may, for example, double the output power capability while reducing parts count and costs. For example, one phase of a three phase inverter is shared between two transformers, which provide power to a rectifier such as a current doubler rectifier to provide two full bridge DC/DC converters with three rather than four high voltage inverter legs.
    Type: Grant
    Filed: June 4, 2004
    Date of Patent: November 13, 2007
    Assignee: Siemens VDO Automotive Corporation
    Inventor: Lizhi Zhu
  • Patent number: 7289329
    Abstract: A power converter integrates at least one planar transformer comprising a multi-layer transformer substrate and/or at least one planar inductor comprising a multi-layer inductor substrate with a number of power semiconductor switches physically and thermally coupled to a heat sink via one or more multi-layer switch substrates.
    Type: Grant
    Filed: October 12, 2004
    Date of Patent: October 30, 2007
    Assignee: Siemens VDO Automotive Corporation
    Inventors: Kanghua Chen, Sayeed Ahmed, Lizhi Zhu
  • Publication number: 20070114954
    Abstract: A system and method for controlling power converters are disclosed. Briefly described, one embodiment is a method comprising communicating at least one first control signal to an alternating current/direct current (AC/DC) power converter from a multi-converter system controller, the AC/DC power converter and the multi-converter system controller residing in a power system electronics housing, and communicating at least one second control signal to a direct current/direct current (DC/DC) power converter from the multi-converter system controller, the DC/DC power converter residing in a power system electronics housing.
    Type: Application
    Filed: November 18, 2005
    Publication date: May 24, 2007
    Inventors: Richard Hampo, John Van Dyke, Lizhi Zhu, Sayeed Ahmed
  • Publication number: 20060152085
    Abstract: Power converter system topologies comprise a first DC/DC converter to pull a positive rail of a high voltage bus up, while a second DC/DC converter pushes a negative rail of the high voltage bus down. One or both the DC/DC converters may be bi-directional. Such topologies are suitable for use with separate primary power sources, and/or auxiliary power sources. Such topologies may include a DC/AC converter, which may be bi-directional. Such topologies may include one or more auxiliary DC/DC converters, which may be bi-directional. Multiple substrates, including at least one stacked above another may enhance packaging.
    Type: Application
    Filed: October 20, 2005
    Publication date: July 13, 2006
    Inventors: Fred Flett, Lizhi Zhu, Sayeed Ahmed, Ajay Patwardhan, Roy Davis
  • Patent number: 7019996
    Abstract: A power converter may employ a planar transformer to minimize winding conduction loss, and the switching devices of the power converter may be aligned in lines parallel to an edge of the planar transformer to minimize the termination leakage inductance. The windings of the planar transformer may be thermally conductively coupled to one or more heat sinks carried by a circuit board which are with respective ones of the switching devices, to provide a cooling path for the planar transformer.
    Type: Grant
    Filed: October 16, 2003
    Date of Patent: March 28, 2006
    Assignee: Ballard Power Systems Corporation
    Inventors: Lizhi Zhu, John M. Van Dyke, Richard J. Hampo
  • Patent number: 7012822
    Abstract: Integrated power conversion systems and methods for use in an electric vehicle having an electric motor, a primary high-voltage energy source, and an auxiliary energy source including a traction inverter module operable for converting a DC current generated by the high-voltage energy source into an AC current capable of powering the electric motor, and a DC/DC converter operable to step-down a voltage of the high-voltage energy source or step-up a voltage of the auxiliary energy source, wherein the traction inverter module and the DC/DC converter may share one or more common components, such as a common high-voltage DC bus capacitor, a common DC bus bar, and/or a common high-voltage transistor.
    Type: Grant
    Filed: February 7, 2003
    Date of Patent: March 14, 2006
    Assignee: Ballard Power Systems Corporation
    Inventors: Lizhi Zhu, Xingyi Xu
  • Publication number: 20050270806
    Abstract: A power converter architecture interleaves full bridge converters to alleviate thermal management problems in high current applications, and may, for example, double the output power capability while reducing parts count and costs. For example, one phase of a three phase inverter is shared between two transformers, which provide power to a rectifier such as a current doubler rectifier to provide two full bridge DC/DC converters with three rather than four high voltage inverter legs.
    Type: Application
    Filed: June 4, 2004
    Publication date: December 8, 2005
    Applicant: Ballard Power Systems Corporation
    Inventor: Lizhi Zhu
  • Publication number: 20050270745
    Abstract: A power converter integrates at least one planar transformer comprising a multi-layer transformer substrate and/or at least one planar inductor comprising a multi-layer inductor substrate with a number of power semiconductor switches physically and thermally coupled to a heat sink via one or more multi-layer switch substrates.
    Type: Application
    Filed: October 12, 2004
    Publication date: December 8, 2005
    Inventors: Kanghua Chen, Sayeed Ahmed, Lizhi Zhu
  • Publication number: 20050254273
    Abstract: A controller implements a state machine for operating the bidirectional power converter with a flexible load pattern while maintaining a thermal condition of the power converter within acceptable limits. The state machine implements a wait loop in response to selected conditions to maintain the thermal condition.
    Type: Application
    Filed: March 30, 2005
    Publication date: November 17, 2005
    Inventors: Christophe Soudier, Lizhi Zhu, Vinod Reddy, Venkatapathi Nallapa
  • Patent number: 6937483
    Abstract: A device and method of commutation control for an isolated boost converter provides a unique commutation logic to limit voltage spikes by utilizing switches on the secondary side to minimize a mismatch between current in the inductor and current in the leakage inductance of the transformer when commutation takes places. To minimize this mismatch, the current in the leakage inductance is preset at a certain level that approaches the current in the inductor prior to the commutation, thus significantly reducing the power rating for a clamp circuit and enabling use of a simple passive clamp circuit. In addition, through unique timing of the turn-on of the secondary switches, soft switching conditions are created that eliminate turn-on losses and the reverse recovery problems of free-wheeling diodes.
    Type: Grant
    Filed: January 15, 2003
    Date of Patent: August 30, 2005
    Assignee: Ballard Power Systems Corporation
    Inventors: Lizhi Zhu, Xingyi Xu