Patents by Inventor Fang Zheng

Fang Zheng 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).

  • Publication number: 20070148016
    Abstract: A reciprocating drive apparatus has a driving device and a driven device, one of the devices comprising a reciprocating member mounted for movement along a longitudinal axis. At least one rotary member is coupled to one of the devices and a linear bearing assembly has a linear guide rail and a linear slide member with an end coupled to the other device. A connecting link has a first end pivotally connected to the rotary member and a second end pivotally linked to the slide member. Where the reciprocating member is the driven device, rotation of the rotary member will cause the reciprocating member to move back and forth along the longitudinal axis.
    Type: Application
    Filed: December 22, 2005
    Publication date: June 28, 2007
    Inventors: Richard Crawford, Fang Zheng, Charles Beuchat
  • Patent number: 7040391
    Abstract: First and second networks of switching devices, each of which are an insulated gate bipolar transistor with an intrinsic reverse-biased clamping diode, are controlled to selectively connect a sinusoidal input voltage and an output to different nodes within a series of capacitors during different portions of input and output voltage cycles to produce a stepped sinusoidal output voltage. The topology requires a low part count, produces relatively low harmonics without filtering when powering artificial lift equipment within a borehole, and scales up to medium voltages without a step-up transformer. During variable speed operation of the lift equipment, optimized switching angles for controlling the switching devices during the voltage cycles may be selected based on modulation producing the desired speed and phase measurements.
    Type: Grant
    Filed: June 30, 2003
    Date of Patent: May 9, 2006
    Assignee: Baker Hughes Incorporated
    Inventors: John Michael Leuthen, Fang Zheng Peng
  • Publication number: 20040267468
    Abstract: First and second networks of switching devices, each of which are an insulated gate bipolar transistor with an intrinsic reverse-biased clamping diode, are controlled to selectively connect a sinusoidal input voltage and an output to different nodes within a series of capacitors during different portions of input and output voltage cycles to produce a stepped sinusoidal output voltage. The topology requires a low part count, produces relatively low harmonics without filtering when powering artificial lift equipment within a borehole, and scales up to medium voltages without a step-up transformer. During variable speed operation of the lift equipment, optimized switching angles for controlling the switching devices during the voltage cycles may be selected based on modulation producing the desired speed and phase measurements.
    Type: Application
    Filed: June 30, 2003
    Publication date: December 30, 2004
    Applicant: Baker Hughes Incorporated
    Inventors: John Michael Leuthen, Fang Zheng Peng
  • Patent number: 6370050
    Abstract: An isolated and soft-switched power converter is used for DC/DC and DC/DC/AC power conversion. The power converter includes two resonant tank circuits coupled back-to-back through an isolation transformer. Each resonant tank circuit includes a pair of resonant capacitors connected in series as a resonant leg, a pair of tank capacitors connected in series as a tank leg, and a pair of switching devices with anti-parallel clamping diodes coupled in series as resonant switches and clamping devices for the resonant leg. The power converter is well suited for DC/DC and DC/DC/AC power conversion applications in which high-voltage isolation, DC to DC voltage boost, bidirectional power flow, and a minimal number of conventional switching components are important design objectives. For example, the power converter is especially well suited to electric vehicle applications and load-side electric generation and storage systems, and other applications in which these objectives are important.
    Type: Grant
    Filed: September 20, 1999
    Date of Patent: April 9, 2002
    Assignee: UT-Batelle, LLC
    Inventors: Fang Zheng Peng, Donald Joe Adams
  • Patent number: 6075350
    Abstract: A power line conditioner using cascade multilevel inverter used for voltage regulation, reactive power (var) compensation and harmonic filtering, including the control schemes for operating the cascade inverter for voltage regulation and harmonic filtering in distribution systems. The cascade M-level inverter consists of (M-1)/2 H-bridges in which each bridge has its own separate DC source. This new inverter (1) can generate almost sinusoidal waveform voltage with only one time switching per line cycle, (2) can eliminate transformers of multipulse inverters used in the conventional static VAR compensators, and (3) makes possible direct connection to the 13.8 kV power distribution system in parallel and series without any transformer. In other words, the power line conditioner is much more efficient and more suitable to VAR compensation and harmonic filtering of distribution systems than traditional multipulse and pulse width modulation (PWM) inverters.
    Type: Grant
    Filed: April 22, 1999
    Date of Patent: June 13, 2000
    Assignee: Lockheed Martin Energy Research Corporation
    Inventor: Fang Zheng Peng
  • Patent number: 5710698
    Abstract: A delta connected, resonant snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the dc supply voltage through the main inverter switches and the auxiliary switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter.
    Type: Grant
    Filed: October 6, 1995
    Date of Patent: January 20, 1998
    Assignee: Lockheed Martin Energy Systems, Inc.
    Inventors: Jih-Sheng Lai, Fang Zheng Peng, Robert W. Young, Sr., George W. Ott, Jr.
  • Patent number: 5644483
    Abstract: A voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter.The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means.
    Type: Grant
    Filed: May 22, 1995
    Date of Patent: July 1, 1997
    Assignee: Lockheed Martin Energy Systems, Inc.
    Inventors: Fang Zheng Peng, Jih-Sheng Lai
  • Patent number: 5642275
    Abstract: A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.
    Type: Grant
    Filed: September 14, 1995
    Date of Patent: June 24, 1997
    Assignee: Lockheed Martin Energy System, Inc.
    Inventors: Fang Zheng Peng, Jih-Sheng Lai
  • Patent number: RE37126
    Abstract: A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.
    Type: Grant
    Filed: October 6, 1998
    Date of Patent: April 3, 2001
    Assignee: Lockheed Martin Energy Systems, Inc.
    Inventors: Fang Zheng Peng, Jih-Sheng Lai