CN117200224A - Three-phase fault ride-through method for continuous low voltage of hybrid cascade direct current system - Google Patents

Three-phase fault ride-through method for continuous low voltage of hybrid cascade direct current system Download PDF

Info

Publication number
CN117200224A
CN117200224A CN202311446786.5A CN202311446786A CN117200224A CN 117200224 A CN117200224 A CN 117200224A CN 202311446786 A CN202311446786 A CN 202311446786A CN 117200224 A CN117200224 A CN 117200224A
Authority
CN
China
Prior art keywords
voltage
hybrid
phase
cascaded
cascade
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202311446786.5A
Other languages
Chinese (zh)
Other versions
CN117200224B (en
Inventor
赵峥
李探
李明
吴方劼
李政
徐莹
马玉龙
牛翀
郑宽
滕尚甫
卢亚军
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
State Grid Corp of China SGCC
State Grid Economic and Technological Research Institute
Xian XJ Power Electronics Technology Co Ltd
Original Assignee
State Grid Corp of China SGCC
State Grid Economic and Technological Research Institute
Xian XJ Power Electronics Technology Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by State Grid Corp of China SGCC, State Grid Economic and Technological Research Institute, Xian XJ Power Electronics Technology Co Ltd filed Critical State Grid Corp of China SGCC
Priority to CN202311446786.5A priority Critical patent/CN117200224B/en
Publication of CN117200224A publication Critical patent/CN117200224A/en
Application granted granted Critical
Publication of CN117200224B publication Critical patent/CN117200224B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/60Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]

Landscapes

  • Inverter Devices (AREA)

Abstract

本发明涉及一种混合级联直流系统持续低电压的三相故障穿越方法,包括:根据混合级联直流系统中柔直换流站的柔直换流变压器网侧的三相交流电压,计算混合级联直流系统的受端的交流电压幅值以及检测柔直换流变压器的近区交流系统三相故障;当检测出柔直换流变压器发生近区交流系统三相故障后,混合级联直流系统的送端移相并保持设定移相时间后解除移相,进入交流故障恢复过程;在交流故障恢复过程中,根据混合级联直流系统的受端的持续低电压的状态和交流电压幅值,混合级联直流系统的送端采用方波式功率限制模式或斜率式功率限制模式,保证混合级联直流系统的送端和受端频率稳定、电压稳定和功角稳定,本发明可以广泛应用于直流输电领域中。

The invention relates to a three-phase fault ride-through method for continuous low voltage in a hybrid cascade DC system, which includes: calculating the hybrid cascaded DC system according to the three-phase AC voltage on the grid side of the flexible-DC converter transformer of the flexible-DC converter station in the hybrid cascade DC system. The AC voltage amplitude at the receiving end of the cascaded DC system and the detection of the three-phase fault of the near-area AC system of the flexible-to-DC converter transformer; when a three-phase fault of the close-area AC system of the flexible-to-DC converter transformer is detected, the hybrid cascaded DC system The sending end is phase-shifted and maintained for the set phase-shifting time, then the phase-shifting is released and the AC fault recovery process is entered; during the AC fault recovery process, according to the continuous low voltage state and AC voltage amplitude of the receiving end of the hybrid cascade DC system, The sending end of the hybrid cascaded DC system adopts square wave power limiting mode or slope power limiting mode to ensure stable frequency, stable voltage and stable power angle at the sending and receiving ends of the hybrid cascaded DC system. The present invention can be widely used in In the field of DC transmission.

Description

一种混合级联直流系统持续低电压的三相故障穿越方法A three-phase fault ride-through method for sustained low voltage in hybrid cascaded DC systems

技术领域Technical field

本发明涉及直流输电领域,特别是关于一种混合级联直流系统持续低电压的三相故障穿越方法。The invention relates to the field of DC power transmission, and in particular to a three-phase fault ride-through method for sustained low voltage in a hybrid cascade DC system.

背景技术Background technique

中国的能源资源与负荷中心呈逆向分布,需稳步推进特高压骨干电网建设,发挥特高压大电网的输送能力。中国的部分负荷中心例如华东地区,直流馈入需求不断增大,但是区外直流的密集馈入将造成换流站间的电气距离减小,多馈入短路比下降,多回直流同时换相失败风险逐渐增大,使电网面临严重的安全稳定问题。为实现远距离大容量输电和多落点供电,解决受端多馈入短路比下降的难题,可采用混合级联特高压直流输电方式,即常规直流换流器和多个柔性直流换流器级联联接的技术方案,该技术方案结合了常规直流和柔性直流的优势,可有效改善受端交流电网的稳定性,且可靠性高,运行方式灵活,具有广泛的应用前景,是构建未来能源互联网的关键技术。China's energy resources and load centers are distributed in reverse directions, and it is necessary to steadily promote the construction of UHV backbone power grids and leverage the transmission capabilities of large UHV power grids. In some load centers in China, such as East China, the demand for DC feed-in continues to increase. However, the intensive DC feed-in outside the region will cause the electrical distance between converter stations to decrease, the short-circuit ratio of multiple feed-ins to decrease, and the simultaneous commutation of multiple DC circuits. The risk of failure is gradually increasing, causing the power grid to face serious security and stability problems. In order to achieve long-distance large-capacity power transmission and multi-point power supply, and solve the problem of reduced short-circuit ratio of multiple feeds at the receiving end, a hybrid cascaded UHV DC transmission method can be used, that is, conventional DC converters and multiple flexible DC converters. The technical solution of cascade connection combines the advantages of conventional DC and flexible DC, which can effectively improve the stability of the AC power grid at the receiving end. It has high reliability, flexible operation mode and wide application prospects. It is the ideal way to build future energy. Key technologies of the Internet.

混合级联特高压直流系统送端采用LCC(电网换相换流器),受端LCC和VSC(电压源换流器)虽分散接入不同的交流落点,但由于受端通常为发达地区,各落点距离依然较近,因而各交流落点之间仍然存在不同程度的电气耦合,单个换流器发生近区三相交流系统故障时,将会同时造成其余换流器网侧交流母线电压不同程度跌落,且易出现交流母线持续低电压的情况,从而引起高端LCC换相失败和VSC输出功率长时受限的连锁故障反应,送端持续注入VSC的直流功率严重盈余,最终导致VSC严重过压或消能装置能量越限,VSC退出运行的严重后果。The hybrid cascaded UHV DC system adopts LCC (grid commutated converter) at the transmitting end. Although the LCC and VSC (voltage source converter) at the receiving end are dispersedly connected to different AC points, the receiving end is usually located in developed areas. , the distance between each drop point is still relatively close, so there are still varying degrees of electrical coupling between each AC drop point. When a single converter fails in the near-area three-phase AC system, it will also cause the grid-side AC bus of other converters to fail. The voltage drops to varying degrees, and the AC bus is prone to sustained low voltage, which causes a chain failure reaction in which the high-end LCC commutation fails and the VSC output power is limited for a long time. The sending end continues to inject the VSC with a serious DC power surplus, eventually leading to the VSC Severe overvoltage or energy dissipation device energy exceeding the limit will cause serious consequences for the VSC to cease operation.

因此,如何降低混合级联直流系统受端近区交流系统三相故障后VSC换流器的直流侧盈余功率,保证系统能够实现各种运行方式下出现持续低电压时的近区交流系统三相故障穿越,是混合级联直流系统安全可靠运行的关键问题,而目前现有技术至均尚未涉及。Therefore, how to reduce the DC side surplus power of the VSC converter after a three-phase fault of the near-area AC system at the receiving end of the hybrid cascade DC system, and ensure that the system can achieve the three-phase near-area AC system when sustained low voltage occurs in various operating modes. Fault ride-through is a key issue for the safe and reliable operation of hybrid cascaded DC systems, which has not yet been addressed by existing technologies.

发明内容Contents of the invention

针对上述问题,本发明的目的是提供一种混合级联直流系统持续低电压的三相故障穿越方法,能够保证系统实现各种运行方式下出现持续低电压时的近区交流系统三相故障穿越。In view of the above problems, the purpose of the present invention is to provide a hybrid cascade DC system continuous low voltage three-phase fault ride-through method, which can ensure that the system realizes the three-phase fault ride-through of the near-area AC system when sustained low voltage occurs in various operating modes. .

为实现上述目的,本发明采取以下技术方案:第一方面,提供一种混合级联直流系统持续低电压的三相故障穿越方法,包括:In order to achieve the above objects, the present invention adopts the following technical solutions: First, a hybrid cascaded DC system provides a continuous low-voltage three-phase fault ride-through method, including:

根据混合级联直流系统中柔直换流站的柔直换流变压器网侧的三相交流电压,计算混合级联直流系统的受端的交流电压幅值以及检测柔直换流变压器的近区交流系统三相故障;According to the three-phase AC voltage on the grid side of the flexible-to-DC converter transformer in the hybrid cascaded DC system, calculate the AC voltage amplitude at the receiving end of the hybrid cascaded DC system and detect the near-area AC of the flexible-to-DC converter transformer. System three-phase fault;

当检测出柔直换流变压器发生近区交流系统三相故障后,混合级联直流系统的送端移相并保持设定移相时间后解除移相,进入交流故障恢复过程;When a three-phase fault in the near-area AC system of the flex-DC converter transformer is detected, the sending end of the hybrid cascade DC system shifts the phase and maintains the set phase shift time, then releases the phase shift and enters the AC fault recovery process;

在交流故障恢复过程中,根据混合级联直流系统的受端的持续低电压的状态和交流电压幅值,混合级联直流系统的送端采用方波式功率限制模式或斜率式功率限制模式,保证混合级联直流系统的送端和受端频率稳定、电压稳定和功角稳定。During the AC fault recovery process, according to the continuous low voltage state and AC voltage amplitude of the receiving end of the hybrid cascaded DC system, the sending end of the hybrid cascaded DC system adopts the square wave power limiting mode or the slope power limiting mode to ensure The frequency, voltage and power angle of the sending and receiving ends of the hybrid cascade DC system are stable.

进一步地,所述根据混合级联直流系统中柔直换流站的柔直换流变压器网侧的三相交流电压,计算混合级联直流系统的受端的交流电压幅值以及检测柔直换流变压器的近区交流系统三相故障,包括:Further, according to the three-phase AC voltage on the grid side of the flexible-to-DC converter transformer of the flexible-to-DC converter station in the hybrid cascaded DC system, the AC voltage amplitude at the receiving end of the hybrid cascaded DC system is calculated and the flexible-to-DC converter is detected. Three-phase faults in the AC system near the transformer include:

实时采集混合级联直流系统中柔直换流站的柔直换流变压器网侧的三相交流电压;Real-time collection of the three-phase AC voltage on the grid side of the flexible-to-DC converter transformer in the hybrid cascaded DC system;

根据实时采集的柔直换流变压器网侧的三相交流电压,计算混合级联直流系统的受端的交流电压幅值;Calculate the AC voltage amplitude at the receiving end of the hybrid cascade DC system based on the three-phase AC voltage collected in real time on the grid side of the flex-DC converter transformer;

根据实时采集的柔直换流变压器网侧的三相交流电压,检测柔直换流变压器的近区交流系统三相故障。Based on the three-phase AC voltage collected in real time on the grid side of the flex-to-dc converter transformer, the three-phase fault of the near-area AC system of the flex-to-dc converter transformer is detected.

进一步地,所述根据实时采集的柔直换流变压器网侧的三相交流电压,计算混合级联直流系统的受端的交流电压幅值,包括:Further, calculating the AC voltage amplitude at the receiving end of the hybrid cascade DC system based on the three-phase AC voltage collected in real time on the grid side of the flex-DC converter transformer includes:

对实时采集的柔直换流变压器网侧的三相交流电压进行CLARK变换,得到两相分量和/>,则交流电压幅值/>为:Perform CLARK transformation on the three-phase AC voltage collected in real time on the grid side of the flex-DC converter transformer to obtain the two-phase components. and/> , then the AC voltage amplitude/> for:

.

进一步地,所述根据实时采集的柔直换流变压器网侧的三相交流电压,检测柔直换流变压器的近区交流系统三相故障,包括:Further, the detection of three-phase faults of the near-area AC system of the flex-to-dc converter transformer based on the three-phase AC voltage on the grid side of the flex-to-dc converter transformer collected in real time includes:

对实时采集的柔直换流变压器网侧的三相交流电压进行正、负序PARK变换,得到dq正序电压分量、/>和dq负序电压分量/>、/>Perform positive and negative sequence PARK transformation on the three-phase AC voltage collected in real time on the grid side of the flex-DC converter transformer to obtain the dq positive sequence voltage component. ,/> and dq negative sequence voltage component/> ,/> ;

根据dq正序电压分量、/>和dq负序电压分量/>、/>,分别计算正序电压分量幅值/>和负序电压分量幅值/>According to the dq positive sequence voltage component ,/> and dq negative sequence voltage component/> ,/> , respectively calculate the positive sequence voltage component amplitude/> and negative sequence voltage component amplitude/> :

当满足且/>时,则判定柔直换流变压器出现近区交流系统三相故障,其中,/>为正序电压分量幅值判断阈值,/>为负序电压分量幅值判断阈值。when satisfied and/> When , it is determined that the flex-DC converter transformer has a three-phase fault in the near-area AC system, where, /> is the positive sequence voltage component amplitude judgment threshold,/> It is the negative sequence voltage component amplitude judgment threshold.

进一步地,所述在交流故障恢复过程中,根据混合级联直流系统的受端的持续低电压的状态和交流电压幅值,混合级联直流系统的送端采用方波式功率限制模式或斜率式功率限制模式,保证混合级联直流系统的送端和受端频率稳定、电压稳定和功角稳定,包括:Furthermore, during the AC fault recovery process, according to the continuous low voltage state of the receiving end of the hybrid cascaded DC system and the AC voltage amplitude, the sending end of the hybrid cascaded DC system adopts the square wave power limiting mode or the slope mode. Power limiting mode ensures stable frequency, stable voltage and stable power angle at the sending and receiving ends of the hybrid cascade DC system, including:

在交流故障恢复过程中,根据混合级联直流系统的受端持续低电压的状态,混合级联直流系统的送端进入功率限制恢复模式,包括方波式功率限制模式和斜率式功率限制模式;During the AC fault recovery process, according to the continuous low voltage state of the receiving end of the hybrid cascaded DC system, the sending end of the hybrid cascaded DC system enters the power limit recovery mode, including square wave power limit mode and slope power limit mode;

混合级联直流系统的送端优先采用方波式功率限制模式,基于混合级联直流系统的受端的交流电压幅值,采用该模式对混合级联直流系统发生近区交流系统三相故障时进行机电-电磁暂态联合仿真,确定采用方波式功率限制模式是否能够保证送端和受端交流系统频率稳定、电压稳定和功角稳定;The transmitting end of the hybrid cascaded DC system preferentially adopts the square wave power limiting mode. Based on the AC voltage amplitude at the receiving end of the hybrid cascaded DC system, this mode is used to detect when a three-phase fault of the near-area AC system occurs in the hybrid cascaded DC system. Electromechanical-electromagnetic transient joint simulation to determine whether the square wave power limitation mode can ensure the frequency stability, voltage stability and power angle stability of the sending and receiving end AC systems;

当采用方波式功率限制模式无法保证送端和受端交流系统稳定时,基于混合级联直流系统的受端的交流电压幅值,采用斜率式功率限制模式,保证送端和受端的频率稳定、电压稳定和功角稳定。When the square wave power limiting mode cannot ensure the stability of the sending and receiving end AC systems, the slope power limiting mode is adopted based on the AC voltage amplitude of the receiving end of the hybrid cascade DC system to ensure the frequency stability of the sending and receiving ends. Voltage stability and power angle stability.

进一步地,所述方波式功率限制模式为:在混合级联直流系统的送端移相后功率恢复时,设置最大恢复功率限制值,将混合级联直流系统的送端最大恢复功率限制在/>且维持时间/>后,再恢复至故障前水平;Further, the square wave power limitation mode is: when the power is restored after the phase shift at the sending end of the hybrid cascade DC system, the maximum restored power limit value is set , limiting the maximum recovery power of the sending end of the hybrid cascade DC system to/> and maintain time/> Afterwards, it returns to the pre-fault level;

所述斜率式功率限制模式为:将混合级联直流系统的受端的交流电压幅值实时通信至送端,送端根据受端的交流母线电压进行对站低电压限流,设定混合级联直流系统的低压限流曲线/>,其中,/>为当前运行方式下混合级联直流系统的额定功率,/>为裕度系数。The slope-type power limiting mode is: the AC voltage amplitude at the receiving end of the hybrid cascade DC system is Communicates to the sending end in real time, and the sending end performs low-voltage current limiting for the station based on the AC bus voltage of the receiving end, and sets the low-voltage current limiting curve of the hybrid cascade DC system/> , where,/> is the rated power of the hybrid cascade DC system under the current operating mode,/> is the margin coefficient.

进一步地,该方法还包括:Further, the method also includes:

对混合级联直流系统中柔直换流站的近区交流系统三相故障进行扫描,获取恢复电压若干毫秒以上的近区交流系统三相故障恢复过程中使消能装置吸收能量最大的持续低电压工况下的交流低电压幅值和低电压持续时间,获取的交流低电压幅值和低电压持续时间用于方波式功率限制模式中最大恢复功率限制值和维持时间的判定。Scan the three-phase fault of the near-area AC system of the flexible-DC converter station in the hybrid cascade DC system to obtain the sustained low voltage that maximizes the energy absorption of the energy dissipation device during the recovery process of the three-phase fault of the near-area AC system for more than several milliseconds. AC low voltage amplitude and low voltage duration under voltage operating conditions. The obtained AC low voltage amplitude and low voltage duration are used to determine the maximum recovery power limit value and maintenance time in the square wave power limit mode.

第二方面,提供一种混合级联直流系统持续低电压的三相故障穿越方法,包括:The second aspect is to provide a continuous low-voltage three-phase fault ride-through method for hybrid cascaded DC systems, including:

近区交流系统三相故障检测模块,用于根据混合级联直流系统中柔直换流站的柔直换流变压器网侧的三相交流电压,计算混合级联直流系统的受端的交流电压幅值以及检测柔直换流变压器的近区交流系统三相故障;The three-phase fault detection module of the near-area AC system is used to calculate the AC voltage amplitude at the receiving end of the hybrid cascade DC system based on the three-phase AC voltage on the grid side of the flexible-DC converter transformer of the flexible-DC converter station in the hybrid cascade DC system. value and detect the three-phase fault of the near-area AC system of the flexible DC converter transformer;

交流故障恢复模块,用于当检测出柔直换流变压器发生近区交流系统三相故障后,混合级联直流系统的送端移相并保持设定移相时间后解除移相,进入交流故障恢复过程;The AC fault recovery module is used to shift the phase of the sending end of the hybrid cascade DC system and maintain the set phase shift time before releasing the phase shift and entering the AC fault after detecting a three-phase fault of the near-area AC system in the flex-DC converter transformer. recovery process;

功率限制恢复模块,用于在交流故障恢复过程中,根据混合级联直流系统的受端的持续低电压的状态和交流电压幅值,混合级联直流系统的送端采用方波式功率限制模式或斜率式功率限制模式,保证混合级联直流系统的送端和受端频率稳定、电压稳定和功角稳定。The power limit recovery module is used during the AC fault recovery process. According to the continuous low voltage state and AC voltage amplitude of the receiving end of the hybrid cascade DC system, the sending end of the hybrid cascade DC system adopts square wave power limiting mode or The slope-type power limiting mode ensures stable frequency, stable voltage and stable power angle at the sending and receiving ends of the hybrid cascade DC system.

第三方面,提供一种处理设备,包括计算机程序指令,其中,所述计算机程序指令被处理设备执行时用于实现上述混合级联直流系统持续低电压的三相故障穿越方法对应的步骤。In a third aspect, a processing device is provided, including computer program instructions, wherein the computer program instructions, when executed by the processing device, are used to implement steps corresponding to the above three-phase fault ride-through method for continuous low voltage in a hybrid cascade DC system.

第四方面,提供一种计算机可读存储介质,所述计算机可读存储介质上存储有计算机程序指令,其中,所述计算机程序指令被处理器执行时用于实现上述混合级联直流系统持续低电压的三相故障穿越方法对应的步骤。In a fourth aspect, a computer-readable storage medium is provided. Computer program instructions are stored on the computer-readable storage medium. The computer program instructions, when executed by a processor, are used to implement the above-mentioned hybrid cascaded DC system with sustained low energy consumption. Corresponding steps for the three-phase fault ride-through method of voltage.

本发明由于采取以上技术方案,其具有以下优点:Since the present invention adopts the above technical solutions, it has the following advantages:

1、本发明提出了一整套交流持续低电压下的故障穿越方法和流程,有效地解决柔性直流交流系统故障时造成长时间持续低电压时直流侧消能装置能量越限的问题,降低了VSC直流侧功率盈余,将消能装置的能量限制在允许范围内,避免消能装置一次设备的投资,保证系统各种运行方式下都能实现持续低电压下的近区交流系统三相故障穿越。1. The present invention proposes a complete set of fault ride-through methods and processes under continuous AC low voltage, which effectively solves the problem of DC side energy dissipation device energy exceeding the limit when the flexible DC AC system fails and causes long-term continuous low voltage, and reduces VSC. The DC side power surplus limits the energy of the energy dissipation device within the allowable range, avoids the investment in primary equipment of the energy dissipation device, and ensures that the three-phase fault ride-through of the near-area AC system under continuous low voltage can be achieved in various operating modes of the system.

2、本发明提出的方波式功率限制模式,无需站间通信,能够保证各类运行方式下故障穿越能力;提出的斜率式功率限制模式,依靠站间通信,但是能最大限度地保留功率传输能力,减小功率损失,两种方案可根据系统需求选取。2. The square wave power limitation mode proposed by the present invention does not require inter-station communication and can ensure the fault ride-through capability under various operating modes; the slope power limitation mode proposed by the present invention relies on inter-station communication but can retain power transmission to the maximum extent. Ability to reduce power loss, two options can be selected according to system requirements.

综上所述,本发明可以广泛应用于直流输电领域中。To sum up, the present invention can be widely used in the field of direct current transmission.

附图说明Description of the drawings

通过阅读下文优选实施方式的详细描述,各种其他的优点和益处对于本领域普通技术人员将变得清楚明了。附图仅用于示出优选实施方式的目的,而并不认为是对本发明的限制。在整个附图中,用相同的附图标记表示相同的部件。在附图中:Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are for the purpose of illustrating preferred embodiments only and are not to be construed as limiting the invention. Throughout the drawings, the same reference numbers refer to the same parts. In the attached picture:

图1是本发明一实施例提供的混合级联直流系统拓扑结构示意图;Figure 1 is a schematic diagram of the topology structure of a hybrid cascaded DC system provided by an embodiment of the present invention;

图2是本发明一实施例提供的方法流程示意图;Figure 2 is a schematic flow chart of a method provided by an embodiment of the present invention;

图3是本发明一实施例提供的混合级联直流系统VSC交流电压幅值计算示意图;Figure 3 is a schematic diagram for calculating the AC voltage amplitude of the hybrid cascade DC system VSC provided by an embodiment of the present invention;

图4是本发明一实施例提供的混合级联直流系统VSC近区交流系统三相故障检测方法的流程示意图。Figure 4 is a schematic flowchart of a three-phase fault detection method for a hybrid cascaded DC system VSC near-area AC system provided by an embodiment of the present invention.

具体实施方式Detailed ways

下面将参照附图更详细地描述本发明的示例性实施方式。虽然附图中显示了本发明的示例性实施方式,然而应当理解,可以以各种形式实现本发明而不应被这里阐述的实施方式所限制。相反,提供这些实施方式是为了能够更透彻地理解本发明,并且能够将本发明的范围完整地传达给本领域的技术人员。Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a thorough understanding of the invention, and to fully convey the scope of the invention to those skilled in the art.

应理解的是,文中使用的术语仅出于描述特定示例实施方式的目的,而无意于进行限制。除非上下文另外明确地指出,否则如文中使用的单数形式“一”、“一个”以及“所述”也可以表示包括复数形式。术语“包括”、“包含”、“含有”以及“具有”是包含性的,并且因此指明所陈述的特征、步骤、操作、元件和/或部件的存在,但并不排除存在或者添加一个或多个其它特征、步骤、操作、元件、部件、和/或它们的组合。文中描述的方法步骤、过程、以及操作不解释为必须要求它们以所描述或说明的特定顺序执行,除非明确指出执行顺序。还应当理解,可以使用另外或者替代的步骤。It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. The terms "comprises", "includes", "contains" and "having" are inclusive and thus indicate the presence of stated features, steps, operations, elements and/or parts but do not exclude the presence or addition of one or Various other features, steps, operations, elements, components, and/or combinations thereof. The method steps, procedures, and operations described herein are not to be construed as requiring that they be performed in the particular order described or illustrated, unless an order of performance is expressly indicated. It should also be understood that additional or alternative steps may be used.

尽管可以在文中使用术语第一、第二、第三等来描述多个元件、部件、区域、层和/或部段,但是,这些元件、部件、区域、层和/或部段不应被这些术语所限制。这些术语可以仅用来将一个元件、部件、区域、层或部段与另一区域、层或部段区分开。除非上下文明确地指出,否则诸如“第一”、“第二”之类的术语以及其它数字术语在文中使用时并不暗示顺序或者次序。因此,以下讨论的第一元件、部件、区域、层或部段在不脱离示例实施方式的教导的情况下可以被称作第二元件、部件、区域、层或部段。Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections shall not be referred to as restricted by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

如图1所示,混合级联直流系统的送端采用常规特高压直流拓扑结构,每极均由2个十二脉动常规直流换流器级联构成;混合级联直流系统的受端采用混合级联直流系统拓扑结构,每极均由高压端(即800kV~400kV)十二脉动常规直流换流器和低压端(400kV~中性线)多个(图中所示为3个)并联的柔性直流换流器级联而成,柔性直流换流器采用半桥型模块化多电平换流器,受端常规直流换流器和每个柔性直流换流器均馈入不同的交流母线。本发明实施例提供的混合级联直流系统持续低电压的三相故障穿越方法,能够有效降低系统受端近区交流系统三相故障后持续低电压下VSC换流器的直流侧盈余功率,保证系统能够实现各种运行方式下的交流故障穿越。As shown in Figure 1, the sending end of the hybrid cascade DC system adopts a conventional UHV DC topology, and each pole is composed of a cascade of two twelve-pulse conventional DC converters; the receiving end of the hybrid cascade DC system adopts a hybrid In the cascade DC system topology, each pole consists of a high-voltage end (i.e. 800kV ~ 400kV) twelve-pulse conventional DC converter and multiple low-voltage ends (400kV ~ neutral line) (three shown in the figure) in parallel. Flexible DC converters are cascaded. The flexible DC converters use half-bridge modular multi-level converters. The conventional DC converters at the receiving end and each flexible DC converter are fed into different AC buses. . The hybrid cascaded DC system's sustained low-voltage three-phase fault ride-through method provided by the embodiment of the present invention can effectively reduce the DC side surplus power of the VSC converter under sustained low voltage after a three-phase fault of the AC system in the near area of the system, ensuring that The system can realize AC fault ride-through in various operating modes.

实施例1Example 1

如图2所示,本实施例提供一种混合级联直流系统持续低电压的三相故障穿越方法,包括以下步骤:As shown in Figure 2, this embodiment provides a hybrid cascade DC system continuous low voltage three-phase fault ride-through method, which includes the following steps:

1)对混合级联直流系统中柔直换流站的近区交流系统三相故障进行扫描,获取恢复电压100毫秒以上的近区交流系统三相故障恢复过程中使消能装置吸收能量最大的持续低电压工况下的交流低电压幅值和低电压持续时间/>1) Scan the three-phase fault of the near-area AC system of the flexible-DC converter station in the hybrid cascade DC system, and obtain the three-phase fault of the near-area AC system with a recovery voltage of more than 100 milliseconds that causes the energy dissipation device to absorb the maximum energy during the recovery process. AC low voltage amplitude under continuous low voltage conditions and low voltage duration/> .

具体地,近区交流系统三相故障扫描方法的过程为:建立混合级联直流系统的机电-电磁混合仿真模型,基于交流系统严苛方式,在混合级联直流系统不同的直流运行方式和各种VSC投入组合下,对近区交流系统三相故障进行全域扫描,获取恢复电压100毫秒以上的近区交流系统三相故障恢复过程中使消能装置吸收能量最大的持续低电压工况下的交流低电压幅值和低电压持续时间/>,其中,交流系统严苛方式指的是交流系统的不同接线和不同运行功率,所谓“严苛”是指在这种方式下消能装置吸收能量大,混合级联直流系统的直流运行方式包括双极全压运行、单极大地返回运行、单极金属返回运行、双极混压运行、单极半压大地返回运行和单极半压金属返回运行等7类,VSC投入组合是指正极负极分别投入的VSC的个数,每极均可能投入1至3个。Specifically, the process of the three-phase fault scanning method of the near-area AC system is: establishing an electromechanical-electromagnetic hybrid simulation model of the hybrid cascaded DC system. Based on the harsh mode of the AC system, the different DC operating modes and various types of the hybrid cascaded DC system are analyzed. With a VSC input combination, a full-range scan is performed on the three-phase fault of the near-area AC system, and the recovery voltage of the three-phase fault of the near-area AC system is more than 100 milliseconds. During the recovery process, the energy dissipation device absorbs the maximum energy under the continuous low-voltage working condition. AC low voltage amplitude and low voltage duration/> , among which, the harsh mode of the AC system refers to the different wiring and different operating power of the AC system. The so-called "harsh" means that the energy dissipation device absorbs a large amount of energy in this mode. The DC operation mode of the hybrid cascade DC system includes There are seven categories: bipolar full voltage operation, unipolar earth return operation, unipolar metal return operation, bipolar mixed pressure operation, unipolar half voltage earth return operation and unipolar half voltage metal return operation. The VSC input combination refers to the positive and negative poles. The number of VSCs that can be input separately can range from 1 to 3 for each pole.

2)根据混合级联直流系统中柔直换流站的柔直换流变压器网侧的三相交流电压,计算混合级联直流系统的受端的交流电压幅值以及检测柔直换流变压器的近区交流系统三相故障,具体为:2) Calculate the AC voltage amplitude at the receiving end of the hybrid cascade DC system based on the three-phase AC voltage on the grid side of the flexible-DC converter transformer in the hybrid cascade DC system. As well as detecting three-phase faults in the near-area AC system of flexible DC converter transformers, specifically:

2.1)实时采集混合级联直流系统中柔直换流站的柔直换流变压器网侧的三相交流电压。2.1) Real-time collection of the three-phase AC voltage on the grid side of the flexible-to-DC converter transformer in the hybrid cascade DC system.

2.2)根据实时采集的柔直换流变压器网侧的三相交流电压,计算混合级联直流系统的受端的交流电压幅值2.2) Calculate the AC voltage amplitude at the receiving end of the hybrid cascade DC system based on the three-phase AC voltage collected in real time on the grid side of the flex-DC converter transformer. .

具体地,如图3所示,对实时采集的柔直换流变压器网侧的三相交流电压进行CLARK变换,得到两相分量和/>,则交流电压幅值/>为:Specifically, as shown in Figure 3, CLARK transformation is performed on the three-phase AC voltage on the grid side of the flex-DC converter transformer collected in real time to obtain the two-phase components. and/> , then the AC voltage amplitude/> for:

(1) (1)

2.3)如图4所示,根据实时采集的柔直换流变压器网侧的三相交流电压,检测柔直换流变压器的近区交流系统三相故障:2.3) As shown in Figure 4, based on the three-phase AC voltage collected in real time on the grid side of the flex-to-dc converter transformer, the three-phase fault of the near-area AC system of the flex-to-dc converter transformer is detected:

2.3.1)对实时采集的柔直换流变压器网侧的三相交流电压进行正、负序PARK变换,得到dq正序电压分量、/>和dq负序电压分量/>、/>2.3.1) Perform positive and negative sequence PARK transformation on the three-phase AC voltage collected in real time on the grid side of the flex-DC converter transformer to obtain the dq positive sequence voltage component ,/> and dq negative sequence voltage component/> ,/> .

2.3.2)根据dq正序电压分量、/>和dq负序电压分量/>、/>,分别计算正序电压分量幅值/>和负序电压分量幅值/>2.3.2) According to the dq positive sequence voltage component ,/> and dq negative sequence voltage component/> ,/> , respectively calculate the positive sequence voltage component amplitude/> and negative sequence voltage component amplitude/> :

(2) (2)

(3) (3)

2.3.3)设置正序电压分量幅值判断阈值和负序电压分量幅值判断阈值2.3.3) Set the positive sequence voltage component amplitude judgment threshold and negative sequence voltage component amplitude judgment threshold .

2.3.4)当满足且/>时,则判定柔直换流变压器出现近区交流系统三相故障。2.3.4) When satisfied and/> When, it is determined that a three-phase fault of the near-area AC system occurs in the flexible-to-DC converter transformer.

3)当检测出柔直换流变压器发生近区交流系统三相故障后,混合级联直流系统的送端移相并保持设定移相时间后解除移相,进入交流故障恢复过程。3) When a three-phase fault of the near-area AC system is detected in the flex-DC converter transformer, the sending end of the hybrid cascade DC system shifts phase and maintains the set phase shift time. Then the phase shift is released and the AC fault recovery process is entered.

4)在交流故障恢复过程中,根据混合级联直流系统的受端的持续低电压的状态和交流电压幅值,混合级联直流系统的送端采用方波式功率限制模式或斜率式功率限制模式,保证混合级联直流系统的送端和受端频率稳定、电压稳定和功角稳定(频率稳定、电压稳定、功角稳定均为术语,是指发生扰动后一定时间内恢复到特定状态的能力),具体为:4) During the AC fault recovery process, according to the continuous low voltage state and AC voltage amplitude of the receiving end of the hybrid cascade DC system , the sending end of the hybrid cascaded DC system adopts square wave power limiting mode or slope power limiting mode to ensure that the sending and receiving ends of the hybrid cascaded DC system have stable frequency, voltage stability and power angle stability (frequency stability, voltage stability , power angle stability are both terms, which refer to the ability to return to a specific state within a certain period of time after a disturbance), specifically:

4.1)在交流故障恢复过程中,根据混合级联直流系统的受端持续低电压的状态,混合级联直流系统的送端进入功率限制恢复模式,包括方波式功率限制模式和斜率式功率限制模式。4.1) During the AC fault recovery process, according to the continuous low voltage state of the receiving end of the hybrid cascade DC system, the sending end of the hybrid cascade DC system enters the power limit recovery mode, including square wave power limit mode and slope power limit. model.

4.2)混合级联直流系统的送端优先采用方波式功率限制模式,基于混合级联直流系统的受端的交流电压幅值,采用该模式对混合级联直流系统发生近区交流系统三相故障时进行机电-电磁暂态联合仿真,确定采用方波式功率限制模式是否能够保证送端和受端交流系统频率稳定、电压稳定和功角稳定。4.2) The sending end of the hybrid cascaded DC system preferentially adopts the square wave power limiting mode, based on the AC voltage amplitude of the receiving end of the hybrid cascaded DC system. , using this mode to conduct electromechanical-electromagnetic transient joint simulation when a three-phase fault occurs in the near-area AC system of the hybrid cascade DC system, to determine whether the square wave power limiting mode can ensure the frequency stability and voltage stability of the sending and receiving end AC systems. Stability and angle stability.

具体地,方波式功率限制模式为:在混合级联直流系统的送端移相后功率恢复时,设置最大恢复功率限制值,将混合级联直流系统的送端最大恢复功率限制在/>且维持时间/>后,再恢复至故障前水平。Specifically, the square wave power limitation mode is: when the power is restored after the phase shift at the sending end of the hybrid cascade DC system, the maximum restored power limit value is set , limiting the maximum recovery power of the sending end of the hybrid cascade DC system to/> and maintain time/> Afterwards, it returns to the pre-fault level.

更具体地,方波式功率限制模式下的最大恢复功率限制值和维持时间满足:/>,/>,其中,/>为系统的额定运行功率,/>为柔直换流变压器网侧额定交流电压。More specifically, the maximum recovery power limit value in square wave power limit mode and maintenance time Satisfy:/> ,/> , where,/> is the rated operating power of the system,/> It is the rated AC voltage on the grid side of the flex-DC converter transformer.

4.3)当采用方波式功率限制模式无法保证送端和受端交流系统稳定时,基于混合级联直流系统的受端的交流电压幅值,采用斜率式功率限制模式,保证送端和受端的频率稳定、电压稳定和功角稳定。4.3) When the square wave power limiting mode cannot ensure the stability of the sending and receiving end AC systems, the AC voltage amplitude of the receiving end based on the hybrid cascade DC system , adopts the slope power limiting mode to ensure the frequency stability, voltage stability and power angle stability of the sending and receiving ends.

具体地,斜率式功率限制模式为:将混合级联直流系统的受端的交流电压幅值实时通信至送端,送端根据受端的交流母线电压进行对站低电压限流,设定混合级联直流系统的低压限流曲线/>,其中,/>为当前运行方式下混合级联直流系统的额定功率,/>为裕度系数,通过设置该系数保证送端发出的直流侧功率小于受端能消纳的功率能力,避免盈余功率,推荐取0.9~1。Specifically, the slope-type power limiting mode is: convert the AC voltage amplitude at the receiving end of the hybrid cascade DC system into Communicates to the sending end in real time, and the sending end performs low-voltage current limiting for the station based on the AC bus voltage of the receiving end, and sets the low-voltage current limiting curve of the hybrid cascade DC system/> , where,/> is the rated power of the hybrid cascade DC system under the current operating mode,/> It is the margin coefficient. By setting this coefficient to ensure that the DC side power emitted by the sending end is less than the power capacity that the receiving end can absorb, to avoid surplus power, it is recommended to be 0.9 to 1.

下面以±800kV/8000MW、受端包括单个LCC和3个VSC的混合级联直流系统的持续低电压近区交流系统三相故障穿越为例,对本发明的方法进行进一步详细说明。Taking the three-phase fault ride-through of a continuous low-voltage near-area AC system of a hybrid cascade DC system with ±800kV/8000MW and a receiving end including a single LCC and three VSCs as an example, the method of the present invention will be further described in detail.

1)建立混合级联直流系统的机电-电磁混合仿真模型,基于交流系统严苛方式,对混合级联直流系统的各种运行方式以及各种VSC投入组合下的近区交流系统三相故障进行全域扫描。本实施例中,利用机电-电磁混合仿真(ADPSS、PSASP)平台,完成双极全压、双极半压、单极全压、单极半压和金属回线等直流方式,并考虑各投入VSC组合(123、12、23、13等),考虑最严苛的冬季高峰方式下进行VSC近区交流系统三相故障全域扫描,得到直流系统近区交流系统三相故障最严酷的低电压运行方式为1+2运行方式(高压端LCC投入运行,低压端2个VSC投入运行),该运行方式下VSC近区交流系统三相故障恢复过程中最严酷的低电压幅值为0.72pu(标幺基值为额定交流电压幅值),低电压持续时间最长为0.9s。1) Establish an electromechanical-electromagnetic hybrid simulation model of the hybrid cascade DC system. Based on the harsh method of the AC system, conduct various operating modes of the hybrid cascade DC system and the three-phase faults of the near-area AC system under various VSC input combinations. Global scan. In this embodiment, the electromechanical-electromagnetic hybrid simulation (ADPSS, PSASP) platform is used to complete the DC modes such as bipolar full voltage, bipolar half voltage, unipolar full voltage, unipolar half voltage and metal loop, and consider each input VSC combination (123, 12, 23, 13, etc.), considering the most severe winter peak mode, conduct a full-field scan of the three-phase faults of the VSC near-area AC system, and obtain the most severe low-voltage operation of the three-phase faults of the DC system near-area AC system The mode is 1+2 operation mode (the high-voltage side LCC is put into operation, and the low-voltage side two VSCs are put into operation). In this operation mode, the most severe low voltage amplitude during the three-phase fault recovery process of the VSC near-area AC system is 0.72pu (standard The unitary value is the rated AC voltage amplitude), and the maximum low voltage duration is 0.9s.

2)根据混合级联直流系统中柔直换流站的柔直换流变压器网侧的三相交流电压,计算混合级联直流系统的受端的交流电压幅值以及检测柔直换流变压器的近区交流系统三相故障。本实施例中,正序电压分量幅值判断阈值/>和负序电压分量幅值判断阈值分别取为0.8pu、0.2pu,当正序电压分量幅值/>和负序电压分量幅值/>满足且/>时,则判定柔直换流变压器出现近区交流系统三相故障。2) Calculate the AC voltage amplitude at the receiving end of the hybrid cascade DC system based on the three-phase AC voltage on the grid side of the flexible-DC converter transformer in the hybrid cascade DC system. and detection of three-phase faults in near-area AC systems of flexible DC converter transformers. In this embodiment, the positive sequence voltage component amplitude judgment threshold/> and negative sequence voltage component amplitude judgment threshold are taken to be 0.8pu and 0.2pu respectively. When the amplitude of the positive sequence voltage component/> and negative sequence voltage component amplitude/> satisfy and/> When, it is determined that a three-phase fault of the near-area AC system occurs in the flexible-to-DC converter transformer.

3)当检测出柔直换流变压器发生近区交流系统三相故障后,混合级联直流系统的送端移相并保持时间后解除移相,进入交流故障恢复过程。本实施例中,/>设置为70ms。3) When a three-phase fault in the near-area AC system is detected in the flex-DC converter transformer, the sending end of the hybrid cascade DC system shifts and maintains the phase. After a certain time, the phase shift is released and the AC fault recovery process is entered. In this embodiment,/> Set to 70ms.

4)在交流故障恢复过程中,根据混合级联直流系统的受端的持续低电压的状态和混合级联直流系统的受端的交流电压幅值以及获取的交流低电压幅值和低电压持续时间,混合级联直流系统的送端采用方波式功率限制模式或斜率式功率限制模式,保证混合级联直流系统的送端和受端频率稳定、电压稳定和功角稳定。本实施例中,经计算采用方波式功率限制模式能够保证混合级联直流系统的送端和受端频率稳定、电压稳定和功角稳定,因此采用该功率限制恢复模式,其中,最大恢复功率限制值/>设置为0.7pu(标幺基值为/>),维持时间/>设置为1s。最终,在采用方波式功率限制模式后,再次对混合级联直流系统的柔直换流站的近区交流系统三相故障进行扫描发现,采用本发明的方法有效降低了VSC直流侧功率盈余,将VSC直流侧消能装置的能量限制在了允许范围内,保证了系统各种运行方式下都能实现持续低电压下的近区交流系统三相故障穿越。4) During the AC fault recovery process, according to the continuous low voltage state of the receiving end of the hybrid cascade DC system and the AC voltage amplitude of the receiving end of the hybrid cascade DC system, as well as the obtained AC low voltage amplitude and low voltage duration , the sending end of the hybrid cascaded DC system adopts the square wave power limiting mode or the slope power limiting mode to ensure the frequency, voltage and power angle stability of the sending and receiving ends of the hybrid cascaded DC system. In this embodiment, it is calculated that the square wave power limitation mode can ensure the frequency stability, voltage stability and power angle stability of the sending and receiving ends of the hybrid cascade DC system. Therefore, this power limitation recovery mode is adopted, where the maximum recovery power Limit value/> Set to 0.7pu (the base value per unit is/> ), maintenance time/> Set to 1s. Finally, after adopting the square wave power limiting mode, the three-phase faults of the near-area AC system of the flexible-DC converter station of the hybrid cascade DC system were scanned again and it was found that the method of the present invention effectively reduced the VSC DC side power surplus. , limiting the energy of the VSC DC side energy dissipation device within the allowable range, ensuring that the three-phase fault ride-through of the near-area AC system under continuous low voltage can be achieved in various operating modes of the system.

实施例2Example 2

本实施例提供一种混合级联直流系统持续低电压的三相故障穿越方法,包括:This embodiment provides a hybrid cascade DC system continuous low voltage three-phase fault ride-through method, including:

故障扫描模块,用于对混合级联直流系统中柔直换流站的近区交流系统三相故障进行扫描,获取恢复电压若干毫秒以上的近区交流系统三相故障恢复过程中使消能装置吸收能量最大的持续低电压工况下的交流低电压幅值和低电压持续时间。The fault scanning module is used to scan the three-phase fault of the near-area AC system at the flexible-DC converter station in the hybrid cascade DC system, and obtain the recovery voltage for more than several milliseconds. The energy dissipation device is used during the recovery process of the three-phase fault of the near-area AC system. AC low voltage amplitude and low voltage duration under sustained low voltage conditions where maximum energy absorption occurs.

近区交流系统三相故障检测模块,用于根据混合级联直流系统中柔直换流站的柔直换流变压器网侧的三相交流电压,计算混合级联直流系统的受端的交流电压幅值以及检测柔直换流变压器的近区交流系统三相故障。The three-phase fault detection module of the near-area AC system is used to calculate the AC voltage amplitude at the receiving end of the hybrid cascade DC system based on the three-phase AC voltage on the grid side of the flexible-DC converter transformer of the flexible-DC converter station in the hybrid cascade DC system. value and detect three-phase faults in the near-area AC system of flexible-to-DC converter transformers.

交流故障恢复模块,用于当检测出柔直换流变压器发生近区交流系统三相故障后,混合级联直流系统的送端移相并保持设定移相时间后解除移相,进入交流故障恢复过程。The AC fault recovery module is used to shift the phase of the sending end of the hybrid cascade DC system and maintain the set phase shift time before releasing the phase shift and entering the AC fault after detecting a three-phase fault of the near-area AC system in the flex-DC converter transformer. recovery process.

功率限制恢复模块,用于在交流故障恢复过程中,根据混合级联直流系统的受端的持续低电压的状态和交流电压幅值,混合级联直流系统的送端采用方波式功率限制模式或斜率式功率限制模式,保证混合级联直流系统的送端和受端频率稳定、电压稳定和功角稳定。The power limit recovery module is used during the AC fault recovery process. According to the continuous low voltage state and AC voltage amplitude of the receiving end of the hybrid cascade DC system, the sending end of the hybrid cascade DC system adopts square wave power limiting mode or The slope-type power limiting mode ensures stable frequency, stable voltage and stable power angle at the sending and receiving ends of the hybrid cascade DC system.

本实施例提供的系统是用于执行上述各方法实施例,具体流程和详细内容请参照上述实施例,此处不再赘述。The system provided by this embodiment is used to execute each of the above method embodiments. Please refer to the above embodiments for specific processes and details, which will not be described again here.

实施例3Example 3

本实施例提供一种与本实施例1所提供的混合级联直流系统持续低电压的三相故障穿越方法对应的处理设备,处理设备可以适用于客户端的处理设备,例如手机、笔记本电脑、平板电脑、台式机电脑等,以执行实施例1的方法。This embodiment provides a processing device corresponding to the continuous low-voltage three-phase fault ride-through method of the hybrid cascade DC system provided in Embodiment 1. The processing device can be suitable for client processing devices, such as mobile phones, laptops, and tablets. Computer, desktop computer, etc., to perform the method of Embodiment 1.

所述处理设备包括处理器、存储器、通信接口和总线,处理器、存储器和通信接口通过总线连接,以完成相互间的通信。存储器中存储有可在处理设备上运行的计算机程序,处理设备运行计算机程序时执行本实施例1所提供的混合级联直流系统持续低电压的三相故障穿越方法。The processing device includes a processor, a memory, a communication interface, and a bus. The processor, the memory, and the communication interface are connected through the bus to complete communication with each other. The memory stores a computer program that can be run on the processing device. When the processing device runs the computer program, it executes the three-phase fault ride-through method for hybrid cascaded DC system with continuous low voltage provided in Embodiment 1.

在一些实现中,存储器可以是高速随机存取存储器(RAM:Random AccessMemory),也可能还包括非不稳定的存储器(non-volatile memory),例如至少一个磁盘存储器。In some implementations, the memory may be high-speed random access memory (RAM: Random Access Memory), and may also include non-volatile memory (non-volatile memory), such as at least one disk memory.

在另一些实现中,处理器可以为中央处理器(CPU)、数字信号处理器(DSP)等各种类型通用处理器,在此不做限定。In other implementations, the processor can be a central processing unit (CPU), a digital signal processor (DSP), and other types of general-purpose processors, which are not limited here.

此外,上述的存储器中的逻辑指令可以通过软件功能单元的形式实现并作为独立的产品销售或使用时,可以存储在一个计算机可读取存储介质中。基于这样的理解,本发明的技术方案本质上或者说对现有技术做出贡献的部分或者该技术方案的部分可以以软件产品的形式体现出来,该计算机软件产品存储在一个存储介质中,包括若干指令用以使得一台计算机设备(可以是个人计算机,服务器,或者网络设备等)执行本发明各个实施例所述方法的全部或部分步骤。而前述的存储介质包括:U盘、移动硬盘、只读存储器(ROM,Read-Only Memory)、随机存取存储器(RAM,Random Access Memory)、磁碟或者光盘等各种可以存储程序代码的介质。In addition, the above-mentioned logical instructions in the memory can be implemented in the form of software functional units and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present invention essentially or the part that contributes to the existing technology or the part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including Several instructions are used to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk and other media that can store program code. .

本领域技术人员可以理解,上述计算设备的结构,仅仅是与本申请方案相关的部分结构,并不构成对本申请方案所应用于其上的计算设备的限定,具体的计算设备可以包括更多或更少的部件,或者组合某些部件,或者具有不同的部件布置。Those skilled in the art can understand that the structure of the above computing device is only a part of the structure related to the solution of the present application, and does not constitute a limitation on the computing device to which the solution of the present application is applied. The specific computing device may include more or Have fewer parts, or combine certain parts, or have different parts arrangements.

实施例4Example 4

本实施例提供一种与本实施例1所提供的混合级联直流系统持续低电压的三相故障穿越方法对应的计算机程序产品,计算机程序产品可以包括计算机可读存储介质,其上载有用于执行本实施例1所述的混合级联直流系统持续低电压的三相故障穿越方法的计算机可读程序指令。This embodiment provides a computer program product corresponding to the continuous low-voltage three-phase fault ride-through method for hybrid cascaded DC systems provided in Embodiment 1. The computer program product may include a computer-readable storage medium on which is uploaded a program for executing Computer-readable program instructions for the hybrid cascaded DC system's continuous low-voltage three-phase fault ride-through method described in Embodiment 1.

计算机可读存储介质可以是保持和存储由指令执行设备使用的指令的有形设备。计算机可读存储介质例如可以是但不限于电存储设备、磁存储设备、光存储设备、电磁存储设备、半导体存储设备或者上述的任意组合。Computer-readable storage media may be tangible devices that retain and store instructions for use by an instruction execution device. The computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any combination of the above.

上述实施例提供的一种计算机可读存储介质,其实现原理和技术效果与上述方法实施例类似,在此不再赘述。The implementation principles and technical effects of the computer-readable storage medium provided by the above embodiments are similar to those of the above method embodiments, and will not be described again here.

本申请是参照根据本申请实施例的方法、设备(系统)、和计算机程序产品的流程图和/或方框图来描述的。应理解可由计算机程序指令实现流程图和/或方框图中的每一流程和/或方框、以及流程图和/或方框图中的流程和/或方框的结合。可提供这些计算机程序指令到通用计算机、专用计算机、嵌入式处理机或其他可编程数据处理设备的处理器以产生一个机器,使得通过计算机或其他可编程数据处理设备的处理器执行的指令产生用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的装置。The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each process and/or block in the flowchart illustrations and/or block diagrams, and combinations of processes and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine, such that the instructions executed by the processor of the computer or other programmable data processing device produce a use A device for realizing the functions specified in a process or processes in a flowchart and/or a block or blocks in a block diagram.

这些计算机程序指令也可存储在能引导计算机或其他可编程数据处理设备以特定方式工作的计算机可读存储器中,使得存储在该计算机可读存储器中的指令产生包括指令装置的制造品,该指令装置实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能。These computer program instructions may also be stored in a computer-readable memory that causes a computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including the instruction means, the instructions The device implements the functions specified in a process or processes in the flowchart and/or in a block or blocks in the block diagram.

这些计算机程序指令也可装载到计算机或其他可编程数据处理设备上,使得在计算机或其他可编程设备上执行一系列操作步骤以产生计算机实现的处理,从而在计算机或其他可编程设备上执行的指令提供用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的步骤。These computer program instructions may also be loaded onto a computer or other programmable data processing device, causing a series of operating steps to be performed on the computer or other programmable device to produce computer-implemented processing, thereby executing on the computer or other programmable device. Instructions provide steps for implementing the functions specified in a process or processes of a flowchart diagram and/or a block or blocks of a block diagram.

上述各实施例仅用于说明本发明,其中各部件的结构、连接方式和制作工艺等都是可以有所变化的,凡是在本发明技术方案的基础上进行的等同变换和改进,均不应排除在本发明的保护范围之外。The above-mentioned embodiments are only used to illustrate the present invention. The structure, connection method and manufacturing process of each component can be changed. Any equivalent transformations and improvements based on the technical solution of the present invention should not be changed. excluded from the protection scope of the present invention.

Claims (10)

1.一种混合级联直流系统持续低电压的三相故障穿越方法,其特征在于,包括:1. A three-phase fault ride-through method for sustained low voltage in hybrid cascaded DC systems, which is characterized by: 根据混合级联直流系统中柔直换流站的柔直换流变压器网侧的三相交流电压,计算混合级联直流系统的受端的交流电压幅值以及检测柔直换流变压器的近区交流系统三相故障;According to the three-phase AC voltage on the grid side of the flexible-to-DC converter transformer in the hybrid cascaded DC system, calculate the AC voltage amplitude at the receiving end of the hybrid cascaded DC system and detect the near-area AC of the flexible-to-DC converter transformer. System three-phase fault; 当检测出柔直换流变压器发生近区交流系统三相故障后,混合级联直流系统的送端移相并保持设定移相时间后解除移相,进入交流故障恢复过程;When a three-phase fault in the near-area AC system of the flex-DC converter transformer is detected, the sending end of the hybrid cascade DC system shifts the phase and maintains the set phase shift time, then releases the phase shift and enters the AC fault recovery process; 在交流故障恢复过程中,根据混合级联直流系统的受端的持续低电压的状态和交流电压幅值,混合级联直流系统的送端采用方波式功率限制模式或斜率式功率限制模式,保证混合级联直流系统的送端和受端频率稳定、电压稳定和功角稳定。During the AC fault recovery process, according to the continuous low voltage state and AC voltage amplitude of the receiving end of the hybrid cascaded DC system, the sending end of the hybrid cascaded DC system adopts the square wave power limiting mode or the slope power limiting mode to ensure The frequency, voltage and power angle of the sending and receiving ends of the hybrid cascade DC system are stable. 2.如权利要求1所述的一种混合级联直流系统持续低电压的三相故障穿越方法,其特征在于,所述根据混合级联直流系统中柔直换流站的柔直换流变压器网侧的三相交流电压,计算混合级联直流系统的受端的交流电压幅值以及检测柔直换流变压器的近区交流系统三相故障,包括:2. A three-phase fault ride-through method for sustained low voltage in a hybrid cascade DC system as claimed in claim 1, characterized in that the flexible-DC converter transformer of the flexible-DC converter station in the hybrid cascade DC system The three-phase AC voltage on the grid side, calculates the AC voltage amplitude at the receiving end of the hybrid cascade DC system, and detects the three-phase faults of the near-area AC system of the flexible DC converter transformer, including: 实时采集混合级联直流系统中柔直换流站的柔直换流变压器网侧的三相交流电压;Real-time collection of the three-phase AC voltage on the grid side of the flexible-to-DC converter transformer in the hybrid cascaded DC system; 根据实时采集的柔直换流变压器网侧的三相交流电压,计算混合级联直流系统的受端的交流电压幅值;Calculate the AC voltage amplitude at the receiving end of the hybrid cascade DC system based on the three-phase AC voltage collected in real time on the grid side of the flex-DC converter transformer; 根据实时采集的柔直换流变压器网侧的三相交流电压,检测柔直换流变压器的近区交流系统三相故障。Based on the three-phase AC voltage collected in real time on the grid side of the flex-to-dc converter transformer, the three-phase fault of the near-area AC system of the flex-to-dc converter transformer is detected. 3.如权利要求2所述的一种混合级联直流系统持续低电压的三相故障穿越方法,其特征在于,所述根据实时采集的柔直换流变压器网侧的三相交流电压,计算混合级联直流系统的受端的交流电压幅值,包括:3. A three-phase fault ride-through method for hybrid cascaded DC system with continuous low voltage as claimed in claim 2, characterized in that the calculation is based on the three-phase AC voltage collected in real time on the grid side of the flexible DC converter transformer. The AC voltage amplitude at the receiving end of the hybrid cascade DC system includes: 对实时采集的柔直换流变压器网侧的三相交流电压进行CLARK变换,得到两相分量和/>,则交流电压幅值/>为:Perform CLARK transformation on the three-phase AC voltage collected in real time on the grid side of the flex-DC converter transformer to obtain the two-phase components. and/> , then the AC voltage amplitude/> for: . 4.如权利要求2所述的一种混合级联直流系统持续低电压的三相故障穿越方法,其特征在于,所述根据实时采集的柔直换流变压器网侧的三相交流电压,检测柔直换流变压器的近区交流系统三相故障,包括:4. A three-phase fault ride-through method for continuous low voltage in a hybrid cascaded DC system as claimed in claim 2, characterized in that, based on the three-phase AC voltage collected in real time on the grid side of the flexible DC converter transformer, the detection Three-phase faults in the near-area AC system of flexible DC converter transformers include: 对实时采集的柔直换流变压器网侧的三相交流电压进行正、负序PARK变换,得到dq正序电压分量、/>和dq负序电压分量/>、/>Perform positive and negative sequence PARK transformation on the three-phase AC voltage collected in real time on the grid side of the flex-DC converter transformer to obtain the dq positive sequence voltage component. ,/> and dq negative sequence voltage component/> ,/> ; 根据dq正序电压分量、/>和dq负序电压分量/>、/>,分别计算正序电压分量幅值/>和负序电压分量幅值/>According to the dq positive sequence voltage component ,/> and dq negative sequence voltage component/> ,/> , respectively calculate the positive sequence voltage component amplitude/> and negative sequence voltage component amplitude/> : ; 当满足且/>时,则判定柔直换流变压器出现近区交流系统三相故障,其中,/>为正序电压分量幅值判断阈值,/>为负序电压分量幅值判断阈值。when satisfied and/> When , it is determined that the flex-DC converter transformer has a three-phase fault in the near-area AC system, where, /> is the positive sequence voltage component amplitude judgment threshold,/> It is the negative sequence voltage component amplitude judgment threshold. 5.如权利要求1所述的一种混合级联直流系统持续低电压的三相故障穿越方法,其特征在于,所述在交流故障恢复过程中,根据混合级联直流系统的受端的持续低电压的状态和交流电压幅值,混合级联直流系统的送端采用方波式功率限制模式或斜率式功率限制模式,保证混合级联直流系统的送端和受端频率稳定、电压稳定和功角稳定,包括:5. A three-phase fault ride-through method for sustained low voltage in a hybrid cascade DC system as claimed in claim 1, characterized in that, during the AC fault recovery process, according to the sustained low voltage at the receiving end of the hybrid cascade DC system voltage status and AC voltage amplitude, the sending end of the hybrid cascaded DC system adopts the square wave power limiting mode or the slope power limiting mode to ensure the frequency stability, voltage stability and power of the sending and receiving ends of the hybrid cascaded DC system. Angular stabilization, including: 在交流故障恢复过程中,根据混合级联直流系统的受端持续低电压的状态,混合级联直流系统的送端进入功率限制恢复模式,包括方波式功率限制模式和斜率式功率限制模式;During the AC fault recovery process, according to the continuous low voltage state of the receiving end of the hybrid cascaded DC system, the sending end of the hybrid cascaded DC system enters the power limit recovery mode, including square wave power limit mode and slope power limit mode; 混合级联直流系统的送端优先采用方波式功率限制模式,基于混合级联直流系统的受端的交流电压幅值,采用该模式对混合级联直流系统发生近区交流系统三相故障时进行机电-电磁暂态联合仿真,确定采用方波式功率限制模式是否能够保证送端和受端交流系统频率稳定、电压稳定和功角稳定;The transmitting end of the hybrid cascaded DC system preferentially adopts the square wave power limiting mode. Based on the AC voltage amplitude at the receiving end of the hybrid cascaded DC system, this mode is used to detect when a three-phase fault of the near-area AC system occurs in the hybrid cascaded DC system. Electromechanical-electromagnetic transient joint simulation to determine whether the square wave power limitation mode can ensure the frequency stability, voltage stability and power angle stability of the sending and receiving end AC systems; 当采用方波式功率限制模式无法保证送端和受端交流系统稳定时,基于混合级联直流系统的受端的交流电压幅值,采用斜率式功率限制模式,保证送端和受端的频率稳定、电压稳定和功角稳定。When the square wave power limiting mode cannot ensure the stability of the sending and receiving end AC systems, the slope power limiting mode is adopted based on the AC voltage amplitude of the receiving end of the hybrid cascade DC system to ensure the frequency stability of the sending and receiving ends. Voltage stability and power angle stability. 6.如权利要求5所述的一种混合级联直流系统持续低电压的三相故障穿越方法,其特征在于,所述方波式功率限制模式为:在混合级联直流系统的送端移相后功率恢复时,设置最大恢复功率限制值,将混合级联直流系统的送端最大恢复功率限制在/>且维持时间/>后,再恢复至故障前水平;6. A three-phase fault ride-through method for sustained low voltage in a hybrid cascade DC system as claimed in claim 5, characterized in that the square wave power limiting mode is: shifting at the sending end of the hybrid cascade DC system. When the power is restored after the phase, set the maximum restored power limit value , limiting the maximum recovery power of the sending end of the hybrid cascade DC system to/> and maintain time/> Afterwards, it returns to the pre-fault level; 所述斜率式功率限制模式为:将混合级联直流系统的受端的交流电压幅值实时通信至送端,送端根据受端的交流母线电压进行对站低电压限流,设定混合级联直流系统的低压限流曲线/>,其中,/>为当前运行方式下混合级联直流系统的额定功率,/>为裕度系数。The slope-type power limiting mode is: the AC voltage amplitude at the receiving end of the hybrid cascade DC system is Communicates to the sending end in real time, and the sending end performs low-voltage current limiting for the station based on the AC bus voltage of the receiving end, and sets the low-voltage current limiting curve of the hybrid cascade DC system/> , where,/> is the rated power of the hybrid cascade DC system under the current operating mode,/> is the margin coefficient. 7.如权利要求1所述的一种混合级联直流系统持续低电压的三相故障穿越方法,其特征在于,该方法还包括:7. A three-phase fault ride-through method for sustained low voltage in a hybrid cascaded DC system as claimed in claim 1, characterized in that the method further includes: 对混合级联直流系统中柔直换流站的近区交流系统三相故障进行扫描,获取恢复电压若干毫秒以上的近区交流系统三相故障恢复过程中使消能装置吸收能量最大的持续低电压工况下的交流低电压幅值和低电压持续时间,获取的交流低电压幅值和低电压持续时间用于方波式功率限制模式中最大恢复功率限制值和维持时间的判定。Scan the three-phase fault of the near-area AC system of the flexible-DC converter station in the hybrid cascade DC system to obtain the sustained low voltage that maximizes the energy absorption of the energy dissipation device during the recovery process of the three-phase fault of the near-area AC system for more than several milliseconds. AC low voltage amplitude and low voltage duration under voltage operating conditions. The obtained AC low voltage amplitude and low voltage duration are used to determine the maximum recovery power limit value and maintenance time in the square wave power limit mode. 8.一种混合级联直流系统持续低电压的三相故障穿越方法,其特征在于,包括:8. A three-phase fault ride-through method for sustained low voltage in hybrid cascaded DC systems, which is characterized by: 近区交流系统三相故障检测模块,用于根据混合级联直流系统中柔直换流站的柔直换流变压器网侧的三相交流电压,计算混合级联直流系统的受端的交流电压幅值以及检测柔直换流变压器的近区交流系统三相故障;The three-phase fault detection module of the near-area AC system is used to calculate the AC voltage amplitude at the receiving end of the hybrid cascade DC system based on the three-phase AC voltage on the grid side of the flexible-DC converter transformer of the flexible-DC converter station in the hybrid cascade DC system. value and detect the three-phase fault of the near-area AC system of the flexible DC converter transformer; 交流故障恢复模块,用于当检测出柔直换流变压器发生近区交流系统三相故障后,混合级联直流系统的送端移相并保持设定移相时间后解除移相,进入交流故障恢复过程;The AC fault recovery module is used to shift the phase of the sending end of the hybrid cascade DC system and maintain the set phase shift time before releasing the phase shift and entering the AC fault after detecting a three-phase fault of the near-area AC system in the flex-DC converter transformer. recovery process; 功率限制恢复模块,用于在交流故障恢复过程中,根据混合级联直流系统的受端的持续低电压的状态和交流电压幅值,混合级联直流系统的送端采用方波式功率限制模式或斜率式功率限制模式,保证混合级联直流系统的送端和受端频率稳定、电压稳定和功角稳定。The power limit recovery module is used during the AC fault recovery process. According to the continuous low voltage state and AC voltage amplitude of the receiving end of the hybrid cascade DC system, the sending end of the hybrid cascade DC system adopts square wave power limiting mode or The slope-type power limiting mode ensures stable frequency, stable voltage and stable power angle at the sending and receiving ends of the hybrid cascade DC system. 9.一种处理设备,其特征在于,包括计算机程序指令,其中,所述计算机程序指令被处理设备执行时用于实现权利要求1-7中任一项所述的混合级联直流系统持续低电压的三相故障穿越方法对应的步骤。9. A processing device, characterized by comprising computer program instructions, wherein the computer program instructions, when executed by the processing device, are used to implement the hybrid cascaded DC system according to any one of claims 1-7 with continuous low Corresponding steps for the three-phase fault ride-through method of voltage. 10.一种计算机可读存储介质,其特征在于,所述计算机可读存储介质上存储有计算机程序指令,其中,所述计算机程序指令被处理器执行时用于实现权利要求1-7中任一项所述的混合级联直流系统持续低电压的三相故障穿越方法对应的步骤。10. A computer-readable storage medium, characterized in that computer program instructions are stored on the computer-readable storage medium, wherein the computer program instructions are used to implement any of claims 1-7 when executed by a processor. Steps corresponding to the three-phase fault ride-through method for sustained low voltage in hybrid cascaded DC systems described in one item.
CN202311446786.5A 2023-11-02 2023-11-02 Three-phase fault ride-through method for continuous low voltage of hybrid cascade direct current system Active CN117200224B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202311446786.5A CN117200224B (en) 2023-11-02 2023-11-02 Three-phase fault ride-through method for continuous low voltage of hybrid cascade direct current system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202311446786.5A CN117200224B (en) 2023-11-02 2023-11-02 Three-phase fault ride-through method for continuous low voltage of hybrid cascade direct current system

Publications (2)

Publication Number Publication Date
CN117200224A true CN117200224A (en) 2023-12-08
CN117200224B CN117200224B (en) 2024-01-12

Family

ID=88985408

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202311446786.5A Active CN117200224B (en) 2023-11-02 2023-11-02 Three-phase fault ride-through method for continuous low voltage of hybrid cascade direct current system

Country Status (1)

Country Link
CN (1) CN117200224B (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018040466A1 (en) * 2016-08-27 2018-03-08 许继集团有限公司 Direct-current fault ride-through method and computer storage medium
US20210143754A1 (en) * 2019-11-07 2021-05-13 State Grid Jiangsu Electric Power Co., Ltd. Control method for a parallel mmc unit of a lcc-mmc hybrid cascade converter station
CN112952886A (en) * 2021-01-29 2021-06-11 南京南瑞继保电气有限公司 Alternating current fault ride-through method and control system of hybrid cascade direct current system
CN113922410A (en) * 2021-10-26 2022-01-11 国网上海市电力公司 Hybrid DC transmission system and its low-voltage fault ride-through method
CN114583741A (en) * 2022-03-11 2022-06-03 国网经济技术研究院有限公司 Hybrid cascade direct-current transmission power band transfer capability optimization control method and system
CN115102217A (en) * 2022-08-23 2022-09-23 山东大学 A method for determining the stable operation domain of MMC at the receiving end of LCC-MMC hybrid cascaded DC power grid

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018040466A1 (en) * 2016-08-27 2018-03-08 许继集团有限公司 Direct-current fault ride-through method and computer storage medium
US20210143754A1 (en) * 2019-11-07 2021-05-13 State Grid Jiangsu Electric Power Co., Ltd. Control method for a parallel mmc unit of a lcc-mmc hybrid cascade converter station
CN112952886A (en) * 2021-01-29 2021-06-11 南京南瑞继保电气有限公司 Alternating current fault ride-through method and control system of hybrid cascade direct current system
CN113922410A (en) * 2021-10-26 2022-01-11 国网上海市电力公司 Hybrid DC transmission system and its low-voltage fault ride-through method
CN114583741A (en) * 2022-03-11 2022-06-03 国网经济技术研究院有限公司 Hybrid cascade direct-current transmission power band transfer capability optimization control method and system
CN115102217A (en) * 2022-08-23 2022-09-23 山东大学 A method for determining the stable operation domain of MMC at the receiving end of LCC-MMC hybrid cascaded DC power grid

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
刘泽洪 等: "适用于混合级联特高压直流输电系统的可控自恢复消能装置", 《中国电机工程学报》, vol. 41, no. 2 *
彭忠 等: "LCC与VSC级联的特高压混合直流输电系统控制策略", 《电力系统保护与控制》, vol. 49, no. 19 *

Also Published As

Publication number Publication date
CN117200224B (en) 2024-01-12

Similar Documents

Publication Publication Date Title
CN105162155B (en) A kind of series hybrid bipolar direct current transmission system with DC Line Fault ride-through capability
CN103997033B (en) A kind of HVDC transmission system possessing DC Line Fault ride-through capability
CN103107551B (en) Topology circuit used for offshore wind power electric energy delivery
CN107947221A (en) A kind of electric power electric transformer DC Line Fault traversing method
CN109066616A (en) Power distribution network self-adaptive positive sequence current quick-break protection setting method considering photovoltaic access
CN106786723A (en) A kind of hybrid direct current transportation topological structure with DC Line Fault self-cleaning ability
CN115441750A (en) A hybrid AC exchanger
CN110912078B (en) A method and device for locating fault circulating current between turns of a series transformer
CN115001025B (en) Offshore wind power multi-terminal DC transmission system and DC fault active control method thereof
CN103248125A (en) Multi-loop direct-current emergency power modulation system and method based on PMU (power management unit)
CN117200224B (en) Three-phase fault ride-through method for continuous low voltage of hybrid cascade direct current system
WO2024244956A1 (en) Control method and apparatus for bipolar flexible direct-current power transmission system
CN118763713A (en) Surplus power balancing method and device for flexible direct current transmission system during direct current fault period
CN118399464A (en) Method and system for evaluating strength of receiving end power grid
CN109378852B (en) A method and system for obtaining fault measures of DC neutral bus in flexible direct current grid
CN112994065A (en) Method for inhibiting continuous commutation failure of direct current transmission system based on phase modulation operation of photovoltaic power station
CN115663881B (en) A current control method for power system under symmetrical short circuit fault of AC power grid
CN107196325A (en) It is a kind of by mixed-voltage source type current conversion station constitute without dc-couple type direct current network topology
CN113991734B (en) Doubly-fed wind turbine generator control system and method with high voltage ride through capability
CN109103915A (en) Inverter Station topological structure and its control method suitable for the transformation of high-voltage large-capacity Traditional DC engineering receiving end
CN111769549B (en) Emergency power distribution method suitable for extra-high voltage three-terminal hybrid direct current
CN117335479B (en) Method and system for suppressing soft-straight section power-losing overvoltage and alternating-current lightning arrester energy
CN113595125A (en) Transient overvoltage control method and device for high-voltage direct-current power transmission system
He et al. Simulation of large-scale energy storage to improve high-voltage dc stability
Li et al. Study on Topology Structure Optimization Technology Requirements for Large-scale Offshore Wind Power Integration

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant