Patents by Inventor Lixiang Wei

Lixiang Wei 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: 8736091
    Abstract: The present techniques include methods and systems for operating converter to maintain a lifespan of the converter. In some embodiments, the operating frequency of the converter may be increased such that stress may be reduced on the bond wires of the converter. More specifically, embodiments involve calculating the aging parameters for certain operating conditions of the converter operating in a maximum power point tracking (MPPT) mode and determining whether the MPPT operation results in aging the converter to a point which reduces the converter lifespan below a desired lifespan. If the MPPT operation reduces the converter lifespan below the desired lifespan, the frequency of the converter may be increased such that the converter may be controlled to operate at a percentage of MPPT. Thus, in some embodiments, power output may be optimized with respect to maintaining a desired lifespan of the converter.
    Type: Grant
    Filed: June 18, 2010
    Date of Patent: May 27, 2014
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Lixiang Wei, Russel J. Kerkman, Richard A. Lukaszewski, Haihui Lu, Zhenhuan Yuan
  • Publication number: 20140132295
    Abstract: The present techniques include methods and systems for detecting a failure in a capacitor bank of an electrical drive system. Embodiments include using discharge resistors to discharge capacitors in the capacitor bank, forming a neutral node of the capacitor bank. In different capacitor configurations, the neutral node is measured, and the voltage is analyzed to determine whether a capacitor bank unbalance has occurred. In some embodiments, the node is a neutral-to-neutral node between the discharged side of the discharge resistors and a neutral side of the capacitor bank, or between the discharged side of the discharge resistors and a discharged side of a second set of discharge resistors. In some embodiments, the node is a neutral-to-ground node between the discharged side of the discharge resistors and a ground potential.
    Type: Application
    Filed: January 20, 2014
    Publication date: May 15, 2014
    Applicant: ROCKWELL AUTOMATION TECHNOLOGIES, INC.
    Inventors: Yuan Xiao, Lixiang Wei, Doyle F. Busse
  • Patent number: 8698504
    Abstract: A method is provided for detection of a ground fault in a high resistance network in a voltage source power conversion circuit comprising a power converter that converts incoming AC power to DC power applied to a DC bus and an inverter that converts DC power from the DC bus to output AC power. The method includes detecting a midpoint-to-ground voltage between a low side of the DC bus and a ground potential and detecting the presence of a ground fault in a high resistance network based upon the detected midpoint-to-ground voltage.
    Type: Grant
    Filed: October 9, 2010
    Date of Patent: April 15, 2014
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Lixiang Wei, Zhijun Liu, Brian Patrick Brown, David W. Kirschnik, Russ J. Kerkman, Richard A. Lukaszewski, Gary Skibinski, Carlos Daniel Rodriguez-Valdez
  • Publication number: 20140042817
    Abstract: Bypassing methods and apparatus are presented along with power cells and sub cells for multilevel inverters in which DC current flow into a DC link capacitance is interrupted and a bypass switch is closed across a power cell or sub cell output to selectively bypass a power stage of a multilevel inverter.
    Type: Application
    Filed: August 13, 2012
    Publication date: February 13, 2014
    Applicant: ROCKWELL AUTOMATION TECHNOLOGIES, INC.
    Inventors: Navid Zargari, Yuan Xiao, Lixiang Wei
  • Publication number: 20140035492
    Abstract: Single-phase voltage operation techniques are provided for a three-phase drive system. A drive system may include a rectifier configured to couple to a three-phase AC voltage source. The rectifier may be configured to convert AC voltage from the three-phase AC voltage source to a direct current (DC) voltage. The drive system may also include a controller configured to send a plurality of switching signals to a plurality of switches in the rectifier such that the plurality of switching signals minimizes a current provided to the rectifier when only a single-phase of the three-phase AC voltage source is available.
    Type: Application
    Filed: July 31, 2012
    Publication date: February 6, 2014
    Applicant: Rockwell Automation Technologies, Inc.
    Inventors: Ahmed Mohamed Sayed Ahmed, Lixiang Wei, Brian J. Seibel
  • Patent number: 8643383
    Abstract: The present techniques include methods and systems for detecting a failure in a capacitor bank of an electrical drive system. Embodiments include using discharge resistors to discharge capacitors in the capacitor bank, forming a neutral node of the capacitor bank. In different capacitor configurations, the neutral node is measured, and the voltage is analyzed to determine whether a capacitor bank unbalance has occurred. In some embodiments, the node is a neutral-to-neutral node between the discharged side of the discharge resistors and a neutral side of the capacitor bank, or between the discharged side of the discharge resistors and a discharged side of a second set of discharge resistors. In some embodiments, the node is a neutral-to-ground node between the discharged side of the discharge resistors and a ground potential.
    Type: Grant
    Filed: January 28, 2011
    Date of Patent: February 4, 2014
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Yuan Xiao, Lixiang Wei, Doyle F. Busse
  • Patent number: 8593150
    Abstract: A motor drive system provides for analysis of current flow in the DC bus to identify ground faults and their locations. Low-frequency positive polarity and negative polarity current differences indicate ground faults from the positive DC bus and negative DC bus respectively. High-frequency signals indicate ground faults in the motor windings and connecting leads.
    Type: Grant
    Filed: November 10, 2010
    Date of Patent: November 26, 2013
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Zoran V. Vrankovic, Lixiang Wei, Gary L. Skibinski, Craig R. Winterhalter
  • Publication number: 20130286692
    Abstract: Power conversion systems and methods are presented for detecting input filter capacitor degradation or approach of end of operational life based on filter capacitor current measurements using single and/or dual threshold comparisons for computed instantaneous sum of squares of filter currents or power values.
    Type: Application
    Filed: August 9, 2012
    Publication date: October 31, 2013
    Applicant: ROCKWELL AUTOMATION TECHNOLOGIES, INC.
    Inventors: Yogesh Popatlal Patel, Lixiang Wei, Russel J. Kerkman
  • Publication number: 20130286702
    Abstract: The present techniques include methods and systems for operating an inverter to maintain a lifespan of the inverter. In some embodiments, the switching frequency and/or the output current of the inverter may be changed such that stress may be reduced on the inverter bond wires of the inverter. More specifically, embodiments involve calculating the aging parameters for certain operating conditions of the inverter and determining whether the operating conditions result in aging the inverter to a point which reduces the inverter lifespan below a desired lifespan. If the operating conditions reduce the inverter lifespan below the desired lifespan, the switching frequency may be reduced to a lower or minimum switching frequency of the inverter and/or the output current of the inverter may be reduced to a maximum output current at the minimum switching frequency.
    Type: Application
    Filed: June 25, 2013
    Publication date: October 31, 2013
    Inventors: Lixiang Wei, Richard A. Lukaszewski, Russel J. Kerkman
  • Publication number: 20130289911
    Abstract: Power conversion systems and methods are presented for detecting filter capacitor resonance conditions in a power conversion system in which filter currents are measured and filtered using a bandpass filter, and one or more computed mean, RMS, and/or Fourier transform values are computed based on the filtered value(s). The computed measurement value or values are compared with a predetermined threshold and a suspected filter capacitor resonance condition is selectively identified based on comparison result.
    Type: Application
    Filed: August 9, 2012
    Publication date: October 31, 2013
    Applicant: ROCKWELL AUTOMATION TECHNOLOGIES, INC.
    Inventors: Yogesh Popatlal Patel, Lixiang Wei
  • Patent number: 8570003
    Abstract: A double fed induction generator (DFIG) system and controller are presented in which the rotor side converter is preloaded with one or more initial values for resuming regulated operation to counteract transients upon deactivation of the crowbar protection circuit to provide grid fault ride through.
    Type: Grant
    Filed: April 13, 2011
    Date of Patent: October 29, 2013
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Haihui Lu, Zhenhuan Yuan, Lixiang Wei, Russel Kerkman, Richard Lukaszewski, Ahmed Mohamed Sayed Ahmed
  • Patent number: 8570775
    Abstract: Power conversion systems and control techniques are presented in which a bus transient control component bypasses selected phases of a rectifier during a protective mode of operation to reduce common mode voltages or currents.
    Type: Grant
    Filed: February 17, 2011
    Date of Patent: October 29, 2013
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Lixiang Wei, Yuan Xiao, Richard Lukaszewski, Navid R. Zargari
  • Publication number: 20130249501
    Abstract: A double fed induction generator (DFIG) converter method are presented in which rotor side current spikes are attenuated using series-connected damping resistance in response to grid fault occurrences or grid fault clearances.
    Type: Application
    Filed: March 26, 2012
    Publication date: September 26, 2013
    Applicant: Rockwell Automation Technologies, Inc.
    Inventors: Haihui Lu, Zhenhuan Yuan, Lixiang Wei, Russel Kerkman, Richard Lukaszewski, Ahmed Mohamed Sayed Ahmed
  • Publication number: 20130242623
    Abstract: A power conversion system with multiple parallel connected motor drives including a plurality of rectifiers and a corresponding inverters connected by windings of a single common mode choke.
    Type: Application
    Filed: March 15, 2012
    Publication date: September 19, 2013
    Applicant: ROCKWELL AUTOMATION TECHNOLOGIES, INC.
    Inventors: Lixiang Wei, Yuan Xiao, Navid Zargari, Richard Lukaszewski
  • Publication number: 20130241451
    Abstract: Motor drive apparatus and methods are presented in which a standby controller uses at least one switching device to power an inverter in a normal mode and to remove power from the inverter and other motor drive components during a standby mode for improved energy efficiency.
    Type: Application
    Filed: March 13, 2012
    Publication date: September 19, 2013
    Applicant: ROCKWELL AUTOMATION TECHNOLOGIES, INC.
    Inventors: Lixiang Wei, Yogesh Popatlal Patel, Brian P. Brown
  • Patent number: 8537575
    Abstract: A power conversion system and a DC link choke therefore are presented, in which a continuous core structure is provided with first and second legs around which four or more windings are located, with one or more shunt structures providing a magnetic flux path between intermediate portions of the first and second legs.
    Type: Grant
    Filed: February 1, 2013
    Date of Patent: September 17, 2013
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Yuan Xiao, Navid R. Zargari, Zhongyuan Cheng, Lixiang Wei
  • Patent number: 8519655
    Abstract: Embodiments of the present invention provide novel techniques for using a switched converter to provide for three-phase alternating current (AC) rectification, regenerative braking, and direct current (DC) voltage boosting. In particular, one of the three legs of the switched converter is controlled with a set of pulse width modulation (PWM) control signals so that the input AC phase having the highest voltage is rectified and one of the switches in the two other legs is turned on to allow for added voltage. This switching activity allows for voltage from multiple AC line mains to be combined, resulting in an overall boost of the DC voltage of the rectifier. The DC voltage boost can then be applied to the common DC bus in order to ameliorate voltage sags, help with motor starts, and increase the ride-through capability of the motor.
    Type: Grant
    Filed: May 29, 2012
    Date of Patent: August 27, 2013
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Lixiang Wei, Richard A. Lukaszewski, Russel Kerkman, Brian J. Seibel
  • Publication number: 20130218491
    Abstract: The present techniques include methods and systems for detecting a high resistive ground fault condition in an HRG system. Embodiments include systems and methods of measuring drive voltages and detecting voltage changes in the drive once the drive is in operation, particularly for drives operating at relatively low voltages and frequencies. In some embodiments, an integrator is utilized to detect peaks in the measured voltage changes. Relatively small ground currents are also measured to determine HRG faults. Moreover, in some embodiments, the detection of an HRG fault for one of several motor drives provide indication for the particular motor drive in fault.
    Type: Application
    Filed: February 20, 2012
    Publication date: August 22, 2013
    Applicant: ROCKWELL AUTOMATION TECHNOLOGIES, INC.
    Inventors: Lixiang Wei, Zhijun Liu
  • Patent number: 8471516
    Abstract: The present techniques include methods and systems for operating an inverter to maintain a lifespan of the inverter. In some embodiments, the switching frequency and/or the output current of the inverter may be changed such that stress may be reduced on the inverter bond wires of the inverter. More specifically, embodiments involve calculating the aging parameters for certain operating conditions of the inverter and determining whether the operating conditions result in aging the inverter to a point which reduces the inverter lifespan below a desired lifespan. If the operating conditions reduce the inverter lifespan below the desired lifespan, the switching frequency may be reduced to a lower or minimum switching frequency of the inverter and/or the output current of the inverter may be reduced to a maximum output current at the minimum switching frequency.
    Type: Grant
    Filed: May 24, 2010
    Date of Patent: June 25, 2013
    Assignee: Rockwell Automation Technologies, Inc.
    Inventors: Lixiang Wei, Richard A. Lukaszewski, Russel J. Kerkman
  • Publication number: 20130141950
    Abstract: A power conversion system and a DC link choke therefore are presented, in which a continuous core structure is provided with first and second legs around which four or more windings are located, with one or more shunt structures providing a magnetic flux path between intermediate portions of the first and second legs.
    Type: Application
    Filed: February 1, 2013
    Publication date: June 6, 2013
    Applicant: Rockwell Automation Technologies, Inc.
    Inventors: Yuan Xiao, Navid R. Zargari, Zhongyuan Cheng, Lixiang Wei