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公开(公告)号：US11329486B2
公开(公告)日：2022-05-10
申请号：US16607847
申请日：2018-04-27
发明人： Ke Wang , Shunke Sui , Yu Lu , Yunlong Dong , Zhaoqing Hu , Gang Li
摘要： During initiation under an isolated island condition, the amplitude of a voltage reference wave output generated by a flexible DC transmission control and protection system is in a segmented mode, wherein a first segment of the reference wave amplitude begins at zero or a fixed value Ux and rapidly increases to Ua kV at a rate of a kV/s, avoiding a low output voltage reference wave and high error and harmonic content of a sampled voltage and current. A second segment increases to Ub kV at a rate of β kV/s, a third segment increases to Uc kV at a rate of γ kV/s, and the Nth segment increases to a rated voltage of UN kV at a rate of ε kV/s, thereby achieving non-disturbance and shockless initiation of a flexible DC transmission system under an isolated island condition.
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公开(公告)号：US11146071B2
公开(公告)日：2021-10-12
申请号：US16770458
申请日：2018-11-28
发明人： Jiang Lu , Yu Lu , Yunlong Dong , Yongping Wang , Jie Tian , Haiying Li , Zhaoqing Hu , Nannan Wang , Ke Wang , Jiudong Ding
摘要： A coordinated control method for series voltage source converter valve groups comprises: allocating a total direct-current voltage reference value or a total active power reference value at the end where a direct-current electrode series voltage source converter valve group is located according to the total number of voltage source converter valve groups in series; for a direct-current voltage control end, controlling the direct-current voltage of each valve group according to the assigned direct-current voltage reference value for each valve group; for an active power control end, controlling the active power of each valve group according to the assigned active power reference value for each valve group and based on adding the active power compensation amount of the valve group which has voltage equalization effects on the valve group. Correspondingly, also providing a coordinated control device for series voltage source converter valve groups. The direct-current voltage equalization of each valve group in operation of the direct-current voltage control end or the active power control end of the series voltage source converter valve group is achieved.
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公开(公告)号：US10396562B2
公开(公告)日：2019-08-27
申请号：US16319300
申请日：2017-08-15
发明人： 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
摘要： 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.
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4.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：US10461525B2
公开(公告)日：2019-10-29
申请号：US16336064
申请日：2017-08-18
发明人： Zhaoqing Hu , Yunlong Dong , Ke Wang , Haiying Li , Dongming Cao
摘要： A fault current limiting control and protection coordination method for a converter of a flexible direct current transmission system operating in an islanding state is provided. The current output command limit Imax is used to limit the current commands of inner loop currents, and in the event of a fault, Imax is set equal to or slightly larger than a value for an AC line overcurrent protection section.
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公开(公告)号：US10326275B2
公开(公告)日：2019-06-18
申请号：US16086317
申请日：2017-04-19
发明人： Ke Wang , Gang Li , Yu Lu , Yunlong Dong , Jiang Lu , Zhaoqing Hu , Tiangui Jiang
摘要： Provided is a method for controlling a zero sequence voltage of a voltage source converter. When an alternating current system ground fault occurs, a zero sequence voltage at an alternating current (AC) side or a zero sequence voltage at a direct current (DC) side of a converter is detected. If the detected zero sequence voltage is greater than a set value V0ref, a DC side voltage of the converter can be increased to a set value Udc0, thereby generating an appropriate reference wave at the AC side of the converter to match an AC voltage, and accordingly controlling overmodulation of a reference wave at a faulty station to suppress fluctuation of a DC voltage.
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