Patents by Inventor Nannan Wang

Nannan Wang 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: 10923906
    Abstract: A fault switch configuration and clearing method in a flexible DC converter station, the flexible DC converter station is configured with a grid side switch and a valve side phase-split switch in the converter station. When a fault occurs, a faulty phase and a non-faulty phase are detected and identified by means of differential protection or low voltage overcurrent. An alternating current zero crossing condition is created by means of firstly turn off the non-faulty phase valve side phase-split switch and the grid side switch, thereby cutting off the faulty phase, disconnecting the connection between a power supply and a fault point, and achieving the clearing for faults. The described fault-clearing method is simple and practical, highly reliable, and connection between the fault point and the power supply is quickly and effectively cut; converter station equipment is effectively protected, and further expansion of the fault is avoided.
    Type: Grant
    Filed: May 22, 2018
    Date of Patent: February 16, 2021
    Assignees: NR ELECTRIC CO., LTD., NR ENGINEERING CO., LTD.
    Inventors: Yu Lu, Gang Li, Jie Tian, Nannan Wang, Haiying Li, Chongxue Jiang, Shunke Sui
  • Publication number: 20200366096
    Abstract: A DC voltage coordination control method is applied to a multi-terminal VSC-HVDC power transmission system or a VSC-HVDC power grid system. When a lower-level control is used in the active power control mode, the active power reference value of the converter is generated according to the converter DC voltage and the converter DC voltage active power curve; it also includes an upper-level control to adjust the control mode and active power setting value of the lower-level control to ensure the steady-state performance of the system. This method has low dependence on communication, avoids the problem that the fixed slope and margin cannot meet all operating conditions, and is suitable for large-scale VSC-HVDC systems, and has scalability.
    Type: Application
    Filed: May 7, 2018
    Publication date: November 19, 2020
    Applicants: NR ELECTRIC CO., LTD, NR ENGINEERING CO., LTD
    Inventors: Nannan WANG, Yu LU, Yunlong DONG, Jie TIAN, Dongming CAO, Haiying LI, Chongxue JIANG, Jiacheng WANG
  • Patent number: 10841202
    Abstract: Systems and methods for identifying a service region that includes sub-regions; calculating, for each pair of neighboring sub-regions, traffic data of computing devices traveling between the pair of sub-region; generating a directed graph representing the service region, the directed graph including nodes representing the sub-regions and the links between the nodes representing the first and the second traffic data; partitioning the directed graph into graph partitions, each graph partition including sub-graphs; calculating, for each sub-graph of each graph partition, a net traffic flow for the sub-graph based on a difference of the first and the second traffic data of the sub-regions that correspond to the nodes of the sub-graph; calculating, for each graph partition, a net traffic flow for the graph partition based on a summation of the net traffic flow of each sub-graph of the graph partition; identifying a particular graph partition having a smallest net traffic flow.
    Type: Grant
    Filed: October 8, 2018
    Date of Patent: November 17, 2020
    Assignee: Fujitsu Limited
    Inventors: Nannan Wang, Xi Wang, Paparao Palacharla, Tadashi Ikeuchi, Weisheng Xie
  • Patent number: 10797487
    Abstract: Provided is an on-line input and quit control method for a voltage-source converter unit. The method achieves the on-line input of a voltage-source converter unit by means of performing steps, such as charging control, deblocking transfer control and operation adjustment control, on a voltage-source converter to be input, and achieves the on-line quitting of the voltage-source converter unit by means of performing steps, such as direct-current voltage reduction control, bypass transfer control and converter blocking control, on a voltage-source converter to be quit. Correspondingly, provided is an on-line input and quit control device for a voltage-source converter unit, which can achieve the on-line steady input and quitting of a voltage-source converter in a series-type hybrid direct-current power transmission system or a series-type flexible direct-current power transmission system, without affecting the normal and stable operation of other already running converters.
    Type: Grant
    Filed: November 24, 2017
    Date of Patent: October 6, 2020
    Assignees: NR ELECTRIC CO., LTD, NR ENGINEERING CO., LTD
    Inventors: Jiang Lu, Yu Lu, Yunlong Dong, Nannan Wang, Yongping Wang, Wenqiang Zhao, Jie Tian, Haiying Li
  • Publication number: 20200295563
    Abstract: Disclosed in the present invention is a voltage and current control method for a direct-current transmission system. The method comprises: calculating a DC voltage reference value of a voltage source converter of a DC voltage control end, on the basis whether a direct-current voltage end of a direct-current pole of a direct-current transmission system substantially controls a direct-current voltage; using ½ of the calculated direct-current voltage reference value of the voltage source converter as a bridge arm voltage direct-current bias, calculating a difference between the direct-current voltage reference value of the voltage source converter and a measured direct-current voltage value, and inputting the difference into a direct-current voltage control outer loop of the voltage source converter to perform closed-loop control, so as to control the direct-current voltage or the direct current of the direct-current pole.
    Type: Application
    Filed: November 28, 2018
    Publication date: September 17, 2020
    Applicants: NR ELECTRIC CO., LTD., NR ENGINEERING CO., LTD.
    Inventors: Jiang LU, Yu LU, Yunlong DONG, Yongping WANG, Jie TIAN, Nannan WANG, Wenqiang ZHAO, Zhaoqing HU, Ke WANG, Jianmin XIAO
  • Publication number: 20200296789
    Abstract: Systems and methods including identifying a physical intelligent moving object (IMO), the physical IMO associated with a current location and a service request; creating, from a digital representation template that is based on the service request, a digital representation instance of the physical IMO in a particular edge cloud of a distributed cloud computing environment that is closest to the current location of the physical IMO; in response to creating the digital representation instance, establishing a network connection between the digital representation and the physical IMO using the particular edge cloud; detecting a movement of the physical IMO from coverage of the particular edge cloud; in response to detecting the movement of the physical IMO: identifying a target edge cloud of the distributed cloud computing environment for coverage of the physical IMO; and establishing a network connection between the digital representation and the physical IMO using the target edge cloud.
    Type: Application
    Filed: March 11, 2019
    Publication date: September 17, 2020
    Applicant: Fujitsu Limited
    Inventors: Xi Wang, Jian Kong, Nannan Wang, Paparao Palacharla, Tadashi Ikeuchi
  • Publication number: 20200220349
    Abstract: A fault switch configuration and clearing method in a flexible DC converter station, the flexible DC converter station is configured with a grid side switch and a valve side phase-split switch in the converter station. When a fault occurs, a faulty phase and a non-faulty phase are detected and identified by means of differential protection or low voltage overcurrent. An alternating current zero crossing condition is created by means of firstly turn off the non-faulty phase valve side phase-split switch and the grid side switch, thereby cutting off the faulty phase, disconnecting the connection between a power supply and a fault point, and achieving the clearing for faults. The described fault-clearing method is simple and practical, highly reliable, and connection between the fault point and the power supply is quickly and effectively cut; converter station equipment is effectively protected, and further expansion of the fault is avoided.
    Type: Application
    Filed: May 22, 2018
    Publication date: July 9, 2020
    Applicants: NR ELECTRIC CO., LTD, NR ENGINEERING CO., LTD
    Inventors: Yu LU, Gang LI, Jie TIAN, Nannan WANG, Haiying LI, Chongxue JIANG, Shunke SUI
  • Publication number: 20200212674
    Abstract: Disclosed are a control method and system for a parallel converter system, including a common AC voltage controller and a separate current controller for each converter; the AC voltage controller generates an active current, a wattless current, and a system voltage phase reference value and, by means of communication, sends same to the current controller of each converter in island control mode to be a converter control signal; the active and wattless current outputted by each converter, along with the corresponding current reference value, accomplish the objective of the parallel converter system collectively controlling the amplitude and frequency of an AC bus voltage. The method and system are highly reliable and effectively ensure the synchronization of a plurality of converters.
    Type: Application
    Filed: May 22, 2018
    Publication date: July 2, 2020
    Inventors: Nannan WANG, Yu LU, Yunlong DONG, Jie TIAN, Chongxue JIANG, Jiacheng WANG, Gang LI, Jiudong DING, Haiying LI
  • Patent number: 10700525
    Abstract: A method and apparatus for controlling a hybrid direct-current (DC) transmission system. The method comprises: adjusting the total number of inserted sub-modules of a modular multi-level converter and the polarity of an output level of the inserted sub-modules in real time, according to a DC voltage of a rectifier station at other end; or adjusting the total number of inserted sub-modules of a modular multi-level converter and the polarity of an output level of the inserted sub-modules in real time, according to the magnitude of a DC current or DC power; or adjusting the total number of inserted sub-modules of a modular multi-level converter and the polarity of an output level of the inserted sub-modules in real time, according to both the magnitude of the DC current and the DC voltage of the rectifier station at the other end. The method can effectively control the DC voltage and the direct current of a hybrid DC transmission system, avoiding the power transmitting breakdown.
    Type: Grant
    Filed: January 19, 2017
    Date of Patent: June 30, 2020
    Assignees: NR ELECTRIC CO., LTD, NR ENGINEERING CO., LTD
    Inventors: Wenqiang Zhao, Nannan Wang, Yongping Wang, Jiang Lu, Chuanjun Bai, Yu Lu
  • Patent number: 10636297
    Abstract: Systems and methods for traffic congestion avoidance may use cooperative autonomous driving based on vehicle-to-vehicle communication to resolve deadlock conditions. The method may include automatically detecting, by a given autonomous vehicle, that the given vehicle is deadlocked, initiating, by the given vehicle, formation of a coordination group including the given vehicle, a front vehicle traveling in the same driving lane as the given vehicle, and an assistant autonomous vehicle traveling in a lane adjacent to the lane in which the given vehicle and the front vehicle are traveling, and sending, by the given vehicle using vehicle-to-vehicle communication, a cooperative driving task request to initiate actions by the autonomous vehicles in the coordination group to resolve the deadlock condition. The actions may include modifying a driving plan of an autonomous vehicle in the coordination group and initiating a speed negotiation with an autonomous vehicle in the coordination group.
    Type: Grant
    Filed: May 24, 2018
    Date of Patent: April 28, 2020
    Assignee: Fujitsu Limited
    Inventors: Nannan Wang, Xi Wang, Qiong Zhang, Paparao Palacharla, Tadashi Ikeuchi
  • Publication number: 20200112502
    Abstract: Systems and methods for identifying a service region that includes sub-regions; calculating, for each pair of neighboring sub-regions, traffic data of computing devices traveling between the pair of sub-region; generating a directed graph representing the service region, the directed graph including nodes representing the sub-regions and the links between the nodes representing the first and the second traffic data; partitioning the directed graph into graph partitions, each graph partition including sub-graphs; calculating, for each sub-graph of each graph partition, a net traffic flow for the sub-graph based on a difference of the first and the second traffic data of the sub-regions that correspond to the nodes of the sub-graph; calculating, for each graph partition, a net traffic flow for the graph partition based on a summation of the net traffic flow of each sub-graph of the graph partition; identifying a particular graph partition having a smallest net traffic flow.
    Type: Application
    Filed: October 8, 2018
    Publication date: April 9, 2020
    Applicant: Fujitsu Limited
    Inventors: Nannan Wang, Xi Wang, Paparao Palacharla, Tadashi Ikeuchi, Weisheng Xie
  • Patent number: 10499156
    Abstract: A method and a device are provided for optimizing a sound signal in the field of voice signal processing. The device includes at least two sound collecting units. In the method, the device locates one or more sound sources via the at least two sound collecting units. The device selects a designated sound source among the one or more sound sources. The device determines a sound signal emitted from the designated sound source among sound signals collected by the sound collecting units according to a spatial position of the designated sound source. The device optimizes the sound signal emitted from the designated sound source.
    Type: Grant
    Filed: March 1, 2016
    Date of Patent: December 3, 2019
    Assignee: XIAOMI INC.
    Inventors: Chiafu Yen, Nannan Wang, Peng Zhang, Liujun Zhang
  • Patent number: 10476261
    Abstract: A method for fault positioning and recovery of a voltage source converter includes following steps. Locking a converter station when it is detected that an alternating-current voltage contains a zero sequence voltage or a direct-current voltage contains an unbalanced voltage. Positioning a fault by continuing to detect the zero sequence voltage of an alternating-current side of the converter. Recovering operation of each station after the fault is positioned. The method for fault positioning and recovery is simple, practical, has high reliability, and can effectively detect the problems that each station contains a zero sequence voltage of an alternating-current side and cannot easily position a fault caused due to transmission of the zero sequence voltage of the alternating-current side to an opposite-side alternating-current system via a voltage source converter.
    Type: Grant
    Filed: April 25, 2017
    Date of Patent: November 12, 2019
    Assignees: NR ELECTRIC CO., LTD, NR ENGINEERING CO., LTD
    Inventors: Gang Li, Yu Lu, Zhaoqing Hu, Jie Tian, Yunlong Dong, Tiangui Jiang, Haiying Li, Yadong Feng, Ke Wang, Jiang Lu, Shunke Sui, Hui Wang, Nannan Wang
  • Patent number: 10396562
    Abstract: A series compensation device suitable to double-circuit lines is disclosed. The device includes one series transformer and one converter. One converter and dual-circuit transmission lines are respectively connected to three windings of one series transformer. In the solution provided in the present application, the device can be independently installed in a power transmission system to be used as a static synchronous series compensator, and can also be used as a component of a unified power flow controller, a convertible static compensator, an interline power flow controller and a unified power quality conditioner to be connected to a power transmission system device in series. The device can save the capacity of a converter, improve the application efficiency of the series compensation device, and reduce the cost and area occupation.
    Type: Grant
    Filed: August 15, 2017
    Date of Patent: August 27, 2019
    Assignees: NR ELECTRIC CO., LTD, NR ENGINEERING CO., LTD
    Inventors: Ruhai Huang, Yu Lu, Yunlong Dong, Lei Pan, Defeng Qiu, Chongxue Jiang, Jiang Lu, Gang Li, Zhaoqing Hu, Nannan Wang, Jiudong Ding, Ke Wang, Xianlai Hu, Hui Wang, Shunke Sui
  • Publication number: 20190252885
    Abstract: Provided is an on-line input and quit control method for a voltage-source converter unit. The method achieves the on-line input of a voltage-source converter unit by means of performing steps, such as charging control, deblocking transfer control and operation adjustment control, on a voltage-source converter to be input, and achieves the on-line quitting of the voltage-source converter unit by means of performing steps, such as direct-current voltage reduction control, bypass transfer control and converter blocking control, on a voltage-source converter to be quit. Correspondingly, provided is an on-line input and quit control device for a voltage-source converter unit, which can achieve the on-line steady input and quitting of a voltage-source converter in a series-type hybrid direct-current power transmission system or a series-type flexible direct-current power transmission system, without affecting the normal and stable operation of other already running converters.
    Type: Application
    Filed: November 24, 2017
    Publication date: August 15, 2019
    Inventors: Jiang Lu, Yu Lu, Yunlong Dong, Nannan Wang, Yongping Wang, Wenqiang Zhao, Jie Tian, Haiying Li
  • Publication number: 20190236948
    Abstract: An intersection management system (IMS) may receive one or more traversing requests from one or more Connected Autonomous Vehicles (CAVs). The IMS may determine a solution space for each of the one or more traversing requests in a space-time resource model of the intersection, find a CAV trajectory allocation in the space-time resource model for each of the one or more traversing requests. The IMS may send an approved reservation to each CAV corresponding to each of the one or more CAV trajectory allocations that have been found. Each of the one or more CAVs may, when an approved reservation corresponding to the CAV may have been received from the IMS, move through the intersection zone as specified in the approved reservation.
    Type: Application
    Filed: November 16, 2018
    Publication date: August 1, 2019
    Applicant: Fujitsu Limited
    Inventors: Nannan Wang, Xi Wang, Paparao Palacharla, Tadashi Ikeuchi
  • Publication number: 20190157871
    Abstract: A series compensation device suitable to double-circuit lines is disclosed. The device includes one series transformer and one converter. One converter and dual-circuit transmission lines are respectively connected to three windings of one series transformer. In the solution provided in the present application, the device can be independently installed in a power transmission system to be used as a static synchronous series compensator, and can also be used as a component of a unified power flow controller, a convertible static compensator, an interline power flow controller and a unified power quality conditioner to be connected to a power transmission system device in series. The device can save the capacity of a converter, improve the application efficiency of the series compensation device, and reduce the cost and area occupation.
    Type: Application
    Filed: August 15, 2017
    Publication date: May 23, 2019
    Applicants: NR Electric Co., Ltd, NR Engineering Co., Ltd
    Inventors: Ruhai HUANG, Yu LU, Yunlong DONG, Lei PAN, Defeng QIU, Chongxue JIANG, Jiang LU, Gang LI, Zhaoqing HU, Nannan WANG, Jiudong DING, Ke WANG, Xianlai HU, Hui WANG, Shunke SUI
  • Publication number: 20190140441
    Abstract: A method for fault positioning and recovery of a voltage source converter includes following steps. Locking a converter station when it is detected that an alternating-current voltage contains a zero sequence voltage or a direct-current voltage contains an unbalanced voltage. Positioning a fault by continuing to detect the zero sequence voltage of an alternating-current side of the converter. Recovering operation of each station after the fault is positioned. The method for fault positioning and recovery is simple, practical, has high reliability, and can effectively detect the problems that each station contains a zero sequence voltage of an alternating-current side and cannot easily position a fault caused due to transmission of the zero sequence voltage of the alternating-current side to an opposite-side alternating-current system via a voltage source converter.
    Type: Application
    Filed: April 25, 2017
    Publication date: May 9, 2019
    Applicants: NR ELECTRIC CO., LTD, NR ENGINEERING CO., LTD
    Inventors: Gang LI, Yu LU, Zhaoqing HU, Jie TIAN, Yunlong DONG, Tiangui JIANG, Haiying LI, Yadong FENG, Ke WANG, Jiang LU, Shunke SUI, Hui WANG, Nannan WANG
  • Patent number: 10283965
    Abstract: A method for incorporating a non-operating station into an operating system in a multi-terminal flexible DC transmission system. The method includes selecting a STATCOM operation mode for the non-operating station; opening a bypass switch at an AC side and connecting a charging resistor to an AC line; closing the AC incoming-line breaker, and pre-charging a converter valve of the non-operating station through the resistor; closing the bypass switch after the pre-charging; selecting a constant-DC voltage control mode for the non-operating station to perform deblocking; controlling the difference between a non-operating station DC voltage value and an operating system direct voltage value to be within an allowable range; closing the pole-connection device at the DC side of a converter of the non-operating station; and switching the non-operating station from the STATCOM operation mode to a DC operation mode, and incorporating the non-operating station into the operating system.
    Type: Grant
    Filed: April 18, 2014
    Date of Patent: May 7, 2019
    Assignees: NR ELECTRIC CO., LTD, NR ENGINEERING CO., LTD
    Inventors: Yunlong Dong, Gang Li, Jie Tian, Nannan Wang, Chao Liu
  • Publication number: 20190051159
    Abstract: Systems and methods for traffic congestion avoidance may use cooperative autonomous driving based on vehicle-to-vehicle communication to resolve deadlock conditions. The method may include automatically detecting, by a given autonomous vehicle, that the given vehicle is deadlocked, initiating, by the given vehicle, formation of a coordination group including the given vehicle, a front vehicle traveling in the same driving lane as the given vehicle, and an assistant autonomous vehicle traveling in a lane adjacent to the lane in which the given vehicle and the front vehicle are traveling, and sending, by the given vehicle using vehicle-to-vehicle communication, a cooperative driving task request to initiate actions by the autonomous vehicles in the coordination group to resolve the deadlock condition. The actions may include modifying a driving plan of an autonomous vehicle in the coordination group and initiating a speed negotiation with an autonomous vehicle in the coordination group.
    Type: Application
    Filed: May 24, 2018
    Publication date: February 14, 2019
    Applicant: Fujitsu Limited
    Inventors: Nannan Wang, Xi Wang, Qiong Zhang, Paparao Palacharla, Tadashi Ikeuchi