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公开(公告)号:US11355932B2
公开(公告)日:2022-06-07
申请号:US16644225
申请日:2018-05-22
发明人: Nannan Wang , Yu Lu , Yunlong Dong , Jie Tian , Chongxue Jiang , Jiacheng Wang , Gang Li , Jiudong Ding , Haiying Li
摘要: 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.
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公开(公告)号:US11190020B2
公开(公告)日:2021-11-30
申请号:US16643472
申请日:2018-05-07
发明人: Nannan Wang , Yu Lu , Yunlong Dong , Jie Tian , Dongming Cao , Haiying Li , Chongxue Jiang , Jiacheng Wang
摘要: 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.
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公开(公告)号:US10164428B2
公开(公告)日:2018-12-25
申请号:US15308842
申请日:2015-02-05
发明人: Guorong Shen , Jie Tian , Dongming Cao , Haiying Li , Yunlong Dong , Nannan Wang , Haibin Liu , Yu Lu
摘要: The disclosure is related to a voltage-source multi-level converter including a phase unit. The phase unit includes first and second bridge arms, each includes modules and reactor connected in series. In the first bridge arm, a first terminal of first reactor is connected to alternating-current terminal of the phrase unit, a second terminal thereof is connected to a first terminal of the first modules, and second terminal of the first modules is connected to first DC terminal of the phrase unit. In the second bridge arm, a first terminal of the second reactor is connected to the alternating-current terminal, a second terminal thereof is connected to a first terminal of the second modules, and a second terminal of the second modules is connected to second DC terminal of the phrase unit. Then, a parallel fault shunt circuit is connected between the second terminals of the first and second reactors.
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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:US10797487B2
公开(公告)日:2020-10-06
申请号:US16345426
申请日:2017-11-24
发明人: Jiang Lu , Yu Lu , Yunlong Dong , Nannan Wang , Yongping Wang , Wenqiang Zhao , Jie Tian , Haiying Li
摘要: 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.
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公开(公告)号:US10396561B2
公开(公告)日:2019-08-27
申请号:US15027434
申请日:2013-07-01
发明人: Yunlong Dong , Jie Tian , Gang Li , Dongming Cao , Haiying Li , Haibin Liu
摘要: The present invention discloses a coordination control method of a multi-terminal VSC-HVDC transmission system. If a direct current voltage master control station shuts down, a direct current voltage control slave station takes over direct current voltage control, and remaining convertor stations keep original control modes. The takeover steps comprise that under the condition that inter-station communications are effective, the master control station sends a shutdown message to the slave station through the inter-station communications, and when the slave station monitors that the direct current voltage master control station shuts down, the slave station switches a current control mode into a direct current voltage control mode; and under the condition that inter-station communications fail or inter-station communications are absent, the slave station monitors changes of the direct current voltage of a system.
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公开(公告)号:US10923906B2
公开(公告)日:2021-02-16
申请号:US16500189
申请日:2018-05-22
发明人: Yu Lu , Gang Li , Jie Tian , Nannan Wang , Haiying Li , Chongxue Jiang , Shunke Sui
摘要: 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.
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公开(公告)号:US10763761B2
公开(公告)日:2020-09-01
申请号:US16469086
申请日:2018-01-12
发明人: Jiudong Ding , Yu Lu , Yunlong Dong , Haiying Li , Jie Tian , Defeng Qiu , Tiangui Jiang , Jianyang Lian
摘要: A sub-module based hybrid converter is provided. By setting a half-controlled charging link of changing full bridge sub-modules from a blocked state to a half-blocked state one by one in a charging process, and raising the voltages of half bridge sub-modules to reach the starting point of a half bridge sub-module based self-powered supply in an uncontrolled stage of the half bridge sub-modules, the starting point of the sub-module based self-powered supply is increased, and the design difficulty of the sub-module based self- powered supply is reduced. The present invention also includes another charging method for a sub-module based hybrid converter.
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公开(公告)号:US10483788B2
公开(公告)日:2019-11-19
申请号:US16466835
申请日:2018-01-12
发明人: Jiudong Ding , Yu Lu , Yunlong Dong , Haiying Li , Jie Tian , Defeng Qiu , Tiangui Jiang , Jianyang Lian
摘要: The present invention discloses a charging method for a sub-module based hybrid converter. By setting a half-controlled charging link of half-blocking all full bridge sub-modules in a charging process, and raising the voltages of half bridge sub-modules to reach the starting point of a half bridge sub-module based self-powered supply in an uncontrolled stage of the half bridge sub-modules, the starting point of the sub-module based self-powered supply is increased, and the design difficulty of the sub-module based self-powered supply is reduced. The present invention also discloses another charging method for a sub-module based hybrid converter. The above objective can also be achieved by setting a half-controlled charging link of bypassing all full bridge sub-modules in the charging process.
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公开(公告)号:US10461534B2
公开(公告)日:2019-10-29
申请号:US15501996
申请日:2015-08-04
发明人: Lei Pan , Jie Tian , Quanrong Shen , Xinbao Wang , Yu Lu , Yunlong Dong , Baoli Chang
摘要: A starting and stopping method for a static synchronous series compensator (SSSC) is provided. A starting process includes: connecting a converter to a shunt transformer, and closing a breaker which connect the AC system and the shunt transformer to charge the converter until the DC voltage is stable; opening the breaker, and connecting the converter to a series transformer through a change-over switch; and deblocking the converter, and controlling a current of a bypass switch of the series transformer to approach zero. A stopping process includes: switching a control mode of the converter to make the current of the bypass switch approaches zero when closed the bypass switch, then controlling a current of the series transformer to be gradually reduced to zero to make the series transformer out of service, and blocking the converter.
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