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公开(公告)号：US09640981B2
公开(公告)日：2017-05-02
申请号：US14426873
申请日：2013-07-01
发明人： Jun Chen , Quanrong Shen , Wei Yan , Huimin Wang , Kai Wang , Huazhong Li
CPC分类号： H02H7/045
摘要： A frequency-conversion differential protection method for an output transformer of a static frequency convertor system. The method comprises: a protection device measuring a three-phase current at each side of an output transformer of an SFC system; according to the connection manner of the output transformer, using a triangle side as a reference to conduct phase correction on a star side; at the same time, taking into account different secondary rated currents at each side of the transformer to adjust a balance coefficient of each side, so as to form sampling values of a correcting current and a differential current at each side, and using a startup and shut-down protection algorithm free from frequency influence in generator protection to calculate amplitude values of the correcting current, the differential current and a restraint current; and according to the magnitudes of the differential current and the restraint current, using the ratio restraint differential characteristic to achieve the frequency-conversion ratio differential protection of the output transformer. The present protection method is suitable for large-scale frequency change. Compared with the current quick-breaking protection, the sensitivity of internal failure detection in the output transformer is greatly improved.
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2.发明申请公开(公告)号：US20150255978A1
公开(公告)日：2015-09-10
申请号：US14426873
申请日：2013-07-01
发明人： Jun Chen , Quanrong Shen , Wei Yan , Huimin Wang , Kai Wang , Huazhong Li
IPC分类号： H02H7/045
CPC分类号： H02H7/045
摘要： A frequency-conversion differential protection method for an output transformer of a static frequency convertor system. The method comprises: a protection device measuring a three-phase current at each side of an output transformer of an SFC system; according to the connection manner of the output transformer, using a triangle side as a reference to conduct phase correction on a star side; at the same time, taking into account different secondary rated currents at each side of the transformer to adjust a balance coefficient of each side, so as to form sampling values of a correcting current and a differential current at each side, and using a startup and shut-down protection algorithm free from frequency influence in generator protection to calculate amplitude values of the correcting current, the differential current and a restraint current; and according to the magnitudes of the differential current and the restraint current, using the ratio restraint differential characteristic to achieve the frequency-conversion ratio differential protection of the output transformer. The present protection method is suitable for large-scale frequency change. Compared with the current quick-breaking protection, the sensitivity of internal failure detection in the output transformer is greatly improved.
摘要翻译： 一种静态变频器输出变压器的变频差动保护方法。 该方法包括：在SFC系统的输出变压器的每一侧测量三相电流的保护装置; 根据输出变压器的连接方式，使用三角形侧作为参考，在星形侧进行相位校正; 同时考虑到变压器两侧的不同次级额定电流，以调整每侧的平衡系数，从而在每一侧形成校正电流和差动电流的采样值，并使用启动和 关闭保护算法在发电机保护中不受频率影响，计算校正电流，差动电流和约束电流的幅值; 并根据差动电流和约束电流的大小，使用比例约束微分特性实现输出变压器的变频比差动保护。 本保护方法适用于大规模变频。 与当前的快速保护相比，输出变压器内部故障检测的灵敏度大大提高。
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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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4.发明授权Current source converter differential protection method and relay protection device 有权电流源转换器差动保护方式及继电保护装置公开(公告)号：US09584007B2
公开(公告)日：2017-02-28
申请号：US14894944
申请日：2014-04-14
发明人： Qixue Zhang , Jun Chen , Wei Yan , Xiangjian Shi , Guang Wang , Wei Yan , Weiqun Liu , Quanrong Shen
CPC分类号： H02M1/32 , H02H3/305 , H02H3/307 , H02H7/1216 , H02M7/04
摘要： Embodiments of the present invention disclose a current source converter differential protection method, including: sampling, by a relay protection device, secondary side currents of current transformers on two sides of a protected current source converter, to obtain incomer-side three-phase currents, and outgoer-side three-phase currents; rectifying the incomer-side three-phase currents and the outgoer-side three-phase currents, to obtain an incomer-side input current and an outgoer-side output current which are equivalent; converting the incomer-side input current and the outgoer-side output current according to a current ratio of the current transformers on the two sides, to acquire a transient differential current and a transient restraint current; acquiring a differential current and a restraint current according to the transient differential current and the transient restraint current; and achieving differential protection according to the differential current and the restraint current. The embodiments of the present invention further disclose a relay protection device correspondingly.
摘要翻译： 本发明的实施例公开了一种电流源转换器差动保护方法，包括：通过继电保护装置对受保护电流源转换器两侧的电流互感器进行二次侧电流的采样，以获得积分端三相电流， 和外侧三相电流; 整流输入端三相电流和外侧三相电流，以获得等效的入射侧输入电流和外侧输出电流; 根据两侧电流互感器的电流比转换入射侧输入电流和外侧输出电流，以获取瞬态差分电流和瞬态约束电流; 根据瞬态微分电流和瞬态约束电流获取差分电流和约束电流; 并根据差动电流和约束电流实现差动保护。 本发明的实施例进一步公开了一种继电保护装置。
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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：US10033186B2
公开(公告)日：2018-07-24
申请号：US15311540
申请日：2015-01-12
发明人： Jie Tian , Haiying Li , Xinbao Wang , Yunlong Dong , Quanrong Shen , Lei Pan , Chao Liu , Baoli Chang
摘要： A unified power flow controller for a double-circuit transmission line comprises at least one parallel-connection transformer, three current converters, at least two series-connection transformers, a parallel-connection side switching circuit, a series-connection side switching circuit and a direct current common bus. The series-connection transformers connected with at least one group of by-pass switches in parallel. The three current converters connected to each loop line in series after being connected with at least one series-connection transformer through the series-connection side switching circuit. The three current converters connected to an alternating current system after connected with at least one parallel-connection transformer through a parallel-connection side switching circuit starting circuit. The three current converters are connected to the direct current common bus through a transfer switch.
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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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公开(公告)号：US20170098936A1
公开(公告)日：2017-04-06
申请号：US15311540
申请日：2015-01-12
发明人： Jie Tian , Haiying Li , Xinbao Wang , Yunlong Dong , Quanrong Shen , Lei Pan , Chao Liu , Baoli Chang
CPC分类号： H02J3/14 , H02J3/16 , H02J3/1814 , H02J3/46 , Y02E40/18
摘要： A unified power flow controller for a double-circuit transmission line comprises at least one parallel-connection transformer, three current converters, at least two series-connection transformers, a parallel-connection side switching circuit, a series-connection side switching circuit and a direct current common bus. The series-connection transformers connected with at least one group of by-pass switches in parallel. The three current converters connected to each loop line in series after being connected with at least one series-connection transformer through the series-connection side switching circuit. The three current converters connected to an alternating current system after connected with at least one parallel-connection transformer through a parallel-connection side switching circuit starting circuit. The three current converters are connected to the direct current common bus through a transfer switch.
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