Patents by Inventor Ying Jiang-Häfner

Ying Jiang-Häfner 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: 12212248
    Abstract: There is provided a method of controlling a plurality of converter cells in a phase arm of a modular multilevel converter (MMC) in accordance with a main reference. The method includes dividing the main reference into a plurality of reference parts, and, by using a grouping of the plurality of converter cells into a plurality of groups, operating a plurality of modulators in parallel, each modulator controlling a respective one of the groups of converter cells in accordance with one of the reference parts. A phase arm controlled in accordance with such a method is also provided, as well as an MMC including at least one such phase arm, and a converter station including at least one such MMC.
    Type: Grant
    Filed: July 7, 2020
    Date of Patent: January 28, 2025
    Assignee: Hitachi Energy Ltd
    Inventors: Jimmy Öhman, Ying-Jiang Hafner, Christer Sjöberg, Daniel Hallmans
  • Publication number: 20250007426
    Abstract: The present application relates to a method for controlling operation of a cell arranged in an arm of a voltage source converter, said arm being associated with a current phase in said voltage source converter. The cell may be a half-bridge or full-bridge cell. The method may comprise: upon detection of a predetermined fault type in the cell, depending on an average current in said arm during one period of fundamental frequency and on an operation mode of the voltage source converter, injecting a pre-defined circulating current into said arm; detecting a time period during which the arm current is in a negative arm current direction corresponding to a direction when arm current flows via a diode of a switch connected in parallel to a bypass switch, and controlling the bypass switch such that it closes within said time period. A control unit and voltage source converter are also provided.
    Type: Application
    Filed: June 25, 2024
    Publication date: January 2, 2025
    Inventors: Ying-Jiang HAFNER, Rakesh REDDY, Ashkan NAMI
  • Publication number: 20240380211
    Abstract: An energy supporting device for a high voltage direct current, HVDC, transmission system includes an energy supporting device for providing grid forming and/or virtual synchronous machine, VSM, capabilities to the HVDC transmission system. The energy supporting device comprises a plurality of cells configured to be connected to the HVDC transmission system, and a cell includes a full-bridge arrangement of power switches, an energy storage device electrically connected to the full-bridge arrangement, a resistor electrically connected between the plurality of cells and an electrical reference potential, and a bypass switch configured to allow the resistor to be bypassed. The energy supporting device is configured to be operated in a dissipation mode, in which the bypass switch is in an open state for allowing the resistor to dissipate electrical energy from the HVDC transmission system, and in which the energy storage devices of the plurality of cells are bypassed.
    Type: Application
    Filed: July 24, 2024
    Publication date: November 14, 2024
    Inventor: Ying-Jiang HAFNER
  • Patent number: 12119655
    Abstract: An energy supporting device for a high voltage direct current, HVDC, transmission system is provided. The HVDC transmission system includes a first HVDC converter and a second HVDC converter connected to each other via an HVDC link. The energy supporting device comprises a plurality of cells configured to be connected in series to the HVDC link, a resistor electrically connected between the plurality of cells and an electrical reference potential, and a bypass switch configured to allow the resistor to be bypassed. A cell includes a full-bridge arrangement of power switches and an energy storage device electrically connected to the full-bridge arrangement.
    Type: Grant
    Filed: June 8, 2021
    Date of Patent: October 15, 2024
    Assignee: Hitachi Energy Ltd
    Inventor: Ying-Jiang Hafner
  • Publication number: 20240266834
    Abstract: An energy supporting device for a high voltage direct current, HVDC, transmission system is provided. The HVDC transmission system includes a first HVDC converter and a second HVDC converter connected to each other via an HVDC link. The energy supporting device comprises a plurality of cells configured to be connected in series to the HVDC link, a resistor electrically connected between the plurality of cells and an electrical reference potential, and a bypass switch configured to allow the resistor to be bypassed. A cell includes a full-bridge arrangement of power switches and an energy storage device electrically connected to the full-bridge arrangement.
    Type: Application
    Filed: June 8, 2021
    Publication date: August 8, 2024
    Inventor: Ying-Jiang HAFNER
  • Publication number: 20230411503
    Abstract: A module (100) is specified, the module (100) comprising a first module connection (108), a second module connection (109), an energy store (105), a first electrical switch (101) and a second electrical switch (102), wherein a switchable bypass device (1) is arranged between the first module connection (108) and the second module connection (109) and wherein the switchable bypass device (1) is configured to remain in a bidirectional current conducting state in response to a single trigger pulse.
    Type: Application
    Filed: November 19, 2021
    Publication date: December 21, 2023
    Inventors: Jan VOBECKY, Ying-Jiang HAFNER
  • Publication number: 20230344363
    Abstract: There is provided a method of controlling a plurality of converter cells in a phase arm of a modular multilevel converter (MMC) in accordance with a main reference. The method includes dividing the main reference into a plurality of reference parts, and, by using a grouping of the plurality of converter cells into a plurality of groups, operating a plurality of modulators in parallel, each modulator controlling a respective one of the groups of converter cells in accordance with one of the reference parts. A phase arm controlled in accordance with such a method is also provided, as well as an MMC including at least one such phase arm, and a converter station including at least one such MMC.
    Type: Application
    Filed: July 7, 2020
    Publication date: October 26, 2023
    Inventors: Jimmy ÖHMAN, Ying-Jiang HAFNER, Christer SJÖBERG, Daniel HALLMANS
  • Patent number: 11476658
    Abstract: A first converter station is part of a high voltage direct current transmission system that includes a DC transmission link connected to the first converter station a second converter station. A DC current and a DC voltage of the DC transmission link are sensed by the first converter station. It is determined that the sensed DC current is equal to or larger than a threshold current value, that the sensed DC current is equal to or larger than the threshold current value, and that at least a partial recovery of the sensed DC voltage has occurred. On the basis that it is determined that the at least a partial recovery of the sensed DC voltage has occurred, it is determined that a phase-to-ground fault has occurred. In response to determining that a phase-to-ground fault has occurred, a power delivered by the first converter station can be reduced.
    Type: Grant
    Filed: December 21, 2017
    Date of Patent: October 18, 2022
    Assignee: Hitachi Energy Switzerland AG
    Inventors: Saurav Roy-Choudhury, Ying Jiang-Häfner, Gaurav-Kumar Kasal, Morteza Mohammadi, Mats Andersson
  • Patent number: 11355925
    Abstract: A neutral arrangement is provided for a converter station of a direct current power transmission system that includes a first converter. The neutral arrangement includes surge arrestors and a group of neutral buses. Each surge arrestor is connected between a neutral bus and ground. The neutral arrangement includes a high voltage insulation zoom area having a first group of surge arrestors and a low voltage insulation zoom area having a second group of surge arrestors. The surge arrestors in the first group have a first arrestor reference voltage and the surge arrestors in the second group have a second arrestor reference voltage that is lower than the first arrestor reference voltage.
    Type: Grant
    Filed: June 1, 2018
    Date of Patent: June 7, 2022
    Assignee: HITACHI ENERGY SWITZERLAND AG
    Inventor: Ying-Jiang Hafner
  • Patent number: 11349384
    Abstract: Methods of energizing converters, and converter stations thereof, based on a mix of half-bridge (HB) converter cells and full-bridge (FB) converter cells are provided. According to one embodiment, a method for energizing a converter may include establishing a direct electrical connection between DC terminals of a converter, electrically connecting the converter to an AC power source via AC connectors and obtaining, from the AC power source and for a certain period of time, an AC voltage between two electrical phase lines for charging capacitors of the FB cells connected to the two electrical phase lines. Accordingly, the FB cells will be charged to a higher value and they may be controlled for charging capacitors of the HB submodules to at least a minimum voltage required to start switching devices of the HB submodules by drawing power from the AC power source.
    Type: Grant
    Filed: February 23, 2018
    Date of Patent: May 31, 2022
    Assignee: Hitachi Energy Switzerland AG
    Inventors: Praveen Kumar Barupati, Ying Jiang-Häfner
  • Patent number: 10931114
    Abstract: A first voltage source converter and converter station including such a first voltage source converter, as well as a method and computer program product for controlling the first voltage source converter are disclosed. The first voltage source converter has a DC side for connection to a DC system, has an AC side for connection to an AC system and is interconnected with an AC side of a second voltage source converter, which has a DC side connected to the DC system. The first voltage source converter includes a number of converter valve pairs, each being connected to a corresponding AC phase of the AC system and a control unit controlling the converter valves to generate at least one AC waveform and to reduce oscillations between the converters.
    Type: Grant
    Filed: August 3, 2017
    Date of Patent: February 23, 2021
    Assignee: ABB POWER GRIDS SWITZERLAND AG
    Inventors: Ying Jiang-Häfner, Adil Abdalrahman, Per Holmberg
  • Publication number: 20200412128
    Abstract: A first converter station is part of a high voltage direct current transmission system that includes a DC transmission link connected to the first converter station a second converter station. A DC current and a DC voltage of the DC transmission link are sensed by the first converter station. It is determined that the sensed DC current is equal to or larger than a threshold current value, that the sensed DC current is equal to or larger than the threshold current value, and that at least a partial recovery of the sensed DC voltage has occurred. On the basis that it is determined that the at least a partial recovery of the sensed DC voltage has occurred, it is determined that a phase-to-ground fault has occurred. In response to determining that a phase-to-ground fault has occurred, a power delivered by the first converter station can be reduced.
    Type: Application
    Filed: December 21, 2017
    Publication date: December 31, 2020
    Inventors: Saurav Roy-Choudhury, Ying Jiang-Häfner, Gaurav-Kumar Kasal, Morteza Mohammadi, Mats Andersson
  • Publication number: 20200373755
    Abstract: A neutral arrangement is provided for a converter station of a direct current power transmission system that includes a first converter. The neutral arrangement includes surge arrestors and a group of neutral buses. Each surge arrestor is connected between a neutral bus and ground. The neutral arrangement includes a high voltage insulation zoom area having a first group of surge arrestors and a low voltage insulation zoom area having a second group of surge arrestors. The surge arrestors in the first group have a first arrestor reference voltage and the surge arrestors in the second group have a second arrestor reference voltage that is lower than the first arrestor reference voltage.
    Type: Application
    Filed: June 1, 2018
    Publication date: November 26, 2020
    Inventor: Ying-Jiang Hafner
  • Publication number: 20200350767
    Abstract: Methods of energizing converters, and converter stations thereof, based on a mix of half-bridge (HB) converter cells and full-bridge (FB) converter cells are provided. According to one embodiment, a method for energizing a converter may include establishing a direct electrical connection between DC terminals of a converter, electrically connecting the converter to an AC power source via AC connectors and obtaining, from the AC power source and for a certain period of time, an AC voltage between two electrical phase lines for charging capacitors of the FB cells connected to the two electrical phase lines. Accordingly, the FB cells will be charged to a higher value and they may be controlled for charging capacitors of the HB submodules to at least a minimum voltage required to start switching devices of the HB submodules by drawing power from the AC power source.
    Type: Application
    Filed: February 23, 2018
    Publication date: November 5, 2020
    Inventors: Praveen Kumar Barupati, Ying Jiang-Häfner
  • Publication number: 20200251906
    Abstract: A first voltage source converter and converter station including such a first voltage source converter, as well as a method and computer program product for controlling the first voltage source converter are disclosed. The first voltage source converter has a DC side for connection to a DC system, has an AC side for connection to an AC system and is interconnected with an AC side of a second voltage source converter, which has a DC side connected to the DC system. The first voltage source converter includes a number of converter valve pairs, each being connected to a corresponding AC phase of the AC system and a control unit controlling the converter valves to generate at least one AC waveform and to reduce oscillations between the converters.
    Type: Application
    Filed: August 3, 2017
    Publication date: August 6, 2020
    Applicant: ABB Power Grids Switzerland AG
    Inventors: Ying JIANG-HÄFNER, Adil ABDALRAHMAN, Per HOLMBERG
  • Patent number: 10374412
    Abstract: A control unit rod interface arrangement couples between AC and DC power systems. The interface includes at least two poles for coupling between the DC and AC power systems. Each of the poles includes a converter for conversion between AC and DC power. If a fault has occurred in one of the poles, a transient current, or fault current, may flow through a neutral bus line connected to the pole, the pole's converter and the location of the fault in the pole. Such a transient or fault current should preferably be damped out as quickly as possible, after which the pole may be electrically isolated from the other components of the interface arrangement.
    Type: Grant
    Filed: October 12, 2015
    Date of Patent: August 6, 2019
    Assignee: ABB Schweiz AG
    Inventors: Sören Nyberg, Yifan Jia, Ying Jiang-Hafner
  • Publication number: 20180287371
    Abstract: A control unit rod interface arrangement couples between AC and DC power systems. The interface includes at least two poles for coupling between the DC and AC power systems. Each of the poles includes a converter for conversion between AC and DC power. If a fault has occurred in one of the poles, a transient current, or fault current, may flow through a neutral bus line connected to the pole, the pole's converter and the location of the fault in the pole. Such a transient or fault current should preferably be damped out as quickly as possible, after which the pole may be electrically isolated from the other components of the interface arrangement.
    Type: Application
    Filed: October 12, 2015
    Publication date: October 4, 2018
    Inventors: Sören Nyberg, Yifan Jia, Ying Jiang-Hafner
  • Patent number: 10050551
    Abstract: An arrangement, method and computer program product are provided for limiting circulating currents in a converter converting between AC and DC. The converter has a number of AC and DC terminals and includes a number of converter arms, where a first and a second converter arm are connected in parallel between a first DC terminal and a first AC terminal. Each converter arm includes a string of series-connected converter cells. The arrangement includes a control unit that obtains a current of the first converter arm and a current of the second converter arm, forms an average of the two converter arm currents, forms a first and a second voltage control signal based on the average and uses the first and second voltage control signal in the control of the voltage provided by the first and second converter arm.
    Type: Grant
    Filed: July 28, 2015
    Date of Patent: August 14, 2018
    Assignee: ABB SCHWEIZ AG
    Inventors: Sri Ramya Kalluri, Gaurav-Kumar Kasal, Ying Jiang-Häfner, Jürgen Häfner
  • Publication number: 20180219491
    Abstract: An arrangement, method and computer program product are provided for limiting circulating currents in a converter converting between AC and DC. The converter has a number of AC and DC terminals and includes a number of converter arms, where a first and a second converter arm are connected in parallel between a first DC terminal and a first AC terminal. Each converter arm includes a string of series-connected converter cells. The arrangement includes a control unit that obtains a current of the first converter arm and a current of the second converter arm, forms an average of the two converter arm currents, forms a first and a second voltage control signal based on the average and uses the first and second voltage control signal in the control of the voltage provided by the first and second converter arm.
    Type: Application
    Filed: July 28, 2015
    Publication date: August 2, 2018
    Applicant: ABB SCHWEIZ AG
    Inventors: Sri Ramya KALLURI, Gaurav-Kumar KASAL, Ying JIANG-HÄFNER, Jürgen HÄFNER
  • Patent number: 9831865
    Abstract: A method for controlling a first and a second reverse-conducting insulated gate bipolar transistor (RC-IGBT), electrically connected in series, is disclosed. A collector of the first RC-IGBT is electrically connected to a positive pole of a direct current voltage source, and an emitter of the second RC-IGBT is electrically connected to a negative pole of the DC voltage source. Further, an emitter of the first RC-IGBT is electrically connected to a collector of the second RC-IGBT to form an alternating current terminal. A gate voltage is applied to respective gates of the first and second RC-IGBTs, wherein the gate voltage is controlled based on a magnitude and a direction of an output current on the AC terminal and on a command signal alternating between a first and a second value.
    Type: Grant
    Filed: April 5, 2013
    Date of Patent: November 28, 2017
    Assignee: ABB SCHWEIZ AG
    Inventors: Annika Lokrantz, Kristoffer Nilsson, Ying Jiang-Häfner, Christer Sjöberg, Lars Döfnäs, Wim Van-Der-Merwe