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公开(公告)号：US20180219380A1
公开(公告)日：2018-08-02
申请号：US15534024
申请日：2015-12-09
发明人： Yunlong Dong , Jie Tian , Zhaoqing Hu , Haiying Li , Dongming Cao , Haibin Liu , Yu Lu
CPC分类号： H02J3/36 , H02H7/1222 , H02J3/38 , H02J2003/388 , H03L7/08 , Y02E60/60
摘要： The present invention discloses a passive islanding to grid-connection switching method for a VSC HVDC transmission system. When the VSC HVDC transmission system in an island operation state, whether the VSC HVDC transmission system enters an grid-connection state is determined by detecting whether an overcurrent phenomenon has occurred in a converter valve-side three-phase alternating-current or a converter bridge arm current, and detecting a change status of an alternating-current side voltage. The system is controlled to switch from an island operation control mode to a grid-connection control mode. At a moment of switching, the online control mode is smoothly switched to by changing a power instruction and performing phase tracking on a current grid voltage, so that continuous operation of the system is maintained.
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公开(公告)号：US09876420B2
公开(公告)日：2018-01-23
申请号：US15528100
申请日：2015-10-28
发明人： Jiudong Ding , Jie Tian , Yunlong Dong , Haiying Li , Dongming Cao , Haibin Liu , Yu Lu
CPC分类号： H02M1/00 , H02M7/00 , H02M7/483 , H02M2001/0003 , H02M2001/325 , H02M2007/4835
摘要： A submodule distributed control method, device and system are provided. Submodules of each bridge arm are grouped. Each group corresponds to one valve based controller. An upper-level control device calculates a weight of each group according to a bridge arm current, an average voltage of normal submodules in each group, and the number of the normal submodules in each group; calculates, according to the number of submodules to be input in a corresponding bridge arm, the number of submodules being input in each group and delivers the number to the valve based controller. The valve based controller operates according to a voltage balancing policy and a gating method that are provided in the prior art.
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23.发明授权公开(公告)号：US11289905B2
公开(公告)日：2022-03-29
申请号：US16767922
申请日：2018-11-28
发明人： Jiang Lu , Yu Lu , Yunlong Dong , Yongping Wang , Jie Tian , Nannan Wang , Wenqiang Zhao , Zhaoqing Hu , Ke Wang , Jianmin Xiao
摘要： 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. Correspondingly, also provided is a voltage and current control device for the direct-current transmission system. By the means of the present invention, the direct-current voltage and the direct current of the direct-current transmission system provided with the voltage source converter can be effectively controlled.
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公开(公告)号：US10476261B2
公开(公告)日：2019-11-12
申请号：US16098878
申请日：2017-04-25
发明人： 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
摘要： 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.
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公开(公告)号：US10418816B2
公开(公告)日：2019-09-17
申请号：US15534024
申请日：2015-12-09
发明人： Yunlong Dong , Jie Tian , Zhaoqing Hu , Haiying Li , Dongming Cao , Haibin Liu , Yu Lu
摘要： The present invention discloses a passive islanding to grid-connection switching method for a VSC HVDC transmission system. When the VSC HVDC transmission system in an island operation state, whether the VSC HVDC transmission system enters an grid-connection state is determined by detecting whether an overcurrent phenomenon has occurred in a converter valve-side three-phase alternating-current or a converter bridge arm current, and detecting a change status of an alternating-current side voltage. The system is controlled to switch from an island operation control mode to a grid-connection control mode. At a moment of switching, the online control mode is smoothly switched to by changing a power instruction and performing phase tracking on a current grid voltage, so that continuous operation of the system is maintained.
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26.发明授权公开(公告)号：US10218184B2
公开(公告)日：2019-02-26
申请号：US15533560
申请日：2015-11-24
发明人： Yunlong Dong , Jie Tian , Dongming Cao , Haiying Li , Jiudong Ding , Zhaoqing Hu , Gang Li , Haibin Liu , Yu Lu
摘要： The present invention provides a method for inhibiting multiple inverter stations from entering a passive control mode in an island state. The method includes dividing inverter stations into groups in advance; a principle for group division is dividing inverter stations whose alternating-current sides are connected to each other through an alternating-current line in a normal running condition into a group; priorities of the inverter stations are preset in each group to tune relevant fixed values of the inverter stations for island detection; a tuning principle is that an inverter station with a higher priority has a more sensitive relevant fixed value, and an island state is more easily detected for the corresponding inverter station; an inverter station for which an island state is detected can enter a passive control mode only when all the other inverter stations with priorities higher than the priority of the inverter station in the group send enabling signals.
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27.发明申请公开(公告)号：US20170331297A1
公开(公告)日：2017-11-16
申请号：US15533560
申请日：2015-11-24
发明人： Yunlong Dong , Jie Tian , Dongming Cao , Haiying Li , Jiudong Ding , Zhaoqing Hu , Gang Li , Haibin Liu , Yu Lu
CPC分类号： H02J3/46 , H02J1/10 , H02J3/00 , H02J3/005 , H02J3/36 , H02J3/38 , H02J2003/001 , H02J2003/388
摘要： The present invention provides a method for inhibiting multiple inverter stations from entering a passive control mode in an island state. The method includes dividing inverter stations into groups in advance; a principle for group division is dividing inverter stations whose alternating-current sides are connected to each other through an alternating-current line in a normal running condition into a group; priorities of the inverter stations are preset in each group to tune relevant fixed values of the inverter stations for island detection; a tuning principle is that an inverter station with a higher priority has a more sensitive relevant fixed value, and an island state is more easily detected for the corresponding inverter station; an inverter station for which an island state is detected can enter a passive control mode only when all the other inverter stations with priorities higher than the priority of the inverter station in the group send enabling signals.
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公开(公告)号：US20160336751A1
公开(公告)日：2016-11-17
申请号：US15111216
申请日：2015-01-22
发明人： Ming Hu , Zhenxia Shao , Xinyan Jiao , Jie Tian , Yu Lu , Gang Shen
CPC分类号： H02J3/36 , H02J1/08 , H02M5/4585 , Y02E60/60
摘要： A tripolar VSC-HVDC system and method, include a rectifier and an inverter formed by a three-phase six-bridge arms modular multilevel converter (MMC) respectively, and two converter valves are arranged on the DC side of the rectifier and inverter respectively. The midpoint of upper and lower converter valves of the rectifier and inverter are connected with a pole 3 DC line by a smoothing reactor. Triggering of the upper and lower converter valves is controlled to change the DC voltage polarity of the pole 3 periodically, and tripolar DC transmission is realized by modulating current orders of the three poles.
摘要翻译： 三极VSC-HVDC系统和方法分别包括由三相六桥臂模块化多电平转换器（MMC）形成的整流器和逆变器，并且在整流器和逆变器的直流侧分别布置两个转换器阀。 整流器和逆变器的上下转换阀的中点通过平滑电抗器与极点3直流线连接。 控制上下转换器阀的触发，周期性地改变极点3的直流电压极性，通过调节三极的电流顺序来实现三极直流传输。
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公开(公告)号：US20170199502A1
公开(公告)日：2017-07-13
申请号：US15324744
申请日：2015-01-22
发明人： Jie Tian , Lei Pan , Chao Liu , Quanrong Shen , Haiying Li , Yu Lu , Yunlong Dong
摘要： A line power control method and system for a unified power flow controller includes outer loop line power control, inner loop valve side current control, and converter valve control. Series-side converter valve side current reference values Isedref and Iseqref are calculated by means of the outer loop line power control according to line power instructions Pref and Qref that are input, a measured line power UL, and measured line power Pline and Qline; a converter output voltage reference value Ucref is calculated by means of the inner valve side current control according to the valve side current reference values that are output by means of the outer loop power control, a measured valve side current, and a measured valve side voltage; and finally, a converter outputs, according to the voltage reference value, a corresponding voltage to control line power to achieve a reference value.
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公开(公告)号：US10250070B2
公开(公告)日：2019-04-02
申请号：US15324744
申请日：2015-01-22
发明人： Jie Tian , Lei Pan , Chao Liu , Quanrong Shen , Haiying Li , Yu Lu , Yunlong Dong
摘要： A line power control method and system for a unified power flow controller includes outer loop line power control, inner loop valve side current control, and converter valve control. Series-side converter valve side current reference values Isedref and Iseqref are calculated by means of the outer loop line power control according to line power instructions Pref and Qref that are input, a measured line power UL, and measured line power Pline and Qline; a converter output voltage reference value Ucref is calculated by means of the inner valve side current control according to the valve side current reference values that are output by means of the outer loop power control, a measured valve side current, and a measured valve side voltage; and finally, a converter outputs, according to the voltage reference value, a corresponding voltage to control line power to achieve a reference value.
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