CN103001191B - Bus differential protection method and system for flexible direct-current closed-loop intelligent power distribution network - Google Patents
Bus differential protection method and system for flexible direct-current closed-loop intelligent power distribution network Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
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Abstract
本发明提供一种柔性直流闭环形智能配电网的母差保护系统及方法，所述系统包括：N条直流母线和N条直流输电线路；每条直流母线与直流输电线路间隔相连，组成柔性直流闭环形智能配电网；其中，N条直流母线中的一条直流母线所在的区域为主节点换流站，其余直流母线所在的区域为子节点换流站；每条直流母线上连接有交流系统整流站；交流系统整流站一端通过直流互感器和直流开关与直流母线连接，另一端连接一交流系统；每条直流母线上还连接用户逆变站和PT；柔性直流闭环形智能配电网的母差保护系统还包括：安装在主节点换流站上的母差保护装置。本发明可以为电压稳定提供支撑，提高电压质量，并且在直流母线发生故障时，可以及时排除故障，保证正常供电。
The invention provides a bus differential protection system and method for a flexible DC closed-loop intelligent distribution network. The system includes: N DC buses and N DC transmission lines; each DC bus is connected to the DC transmission line at intervals to form a flexible DC closed-loop smart distribution network; where one of the N DC buses is located in the area of the main node converter station, and the area where the other DC buses are located is the sub-node converter station; each DC bus is connected to an AC System rectifier station; one end of the AC system rectifier station is connected to the DC busbar through a DC transformer and a DC switch, and the other end is connected to an AC system; each DC busbar is also connected to the user inverter station and PT; flexible DC closed-loop intelligent distribution network The bus differential protection system also includes: the bus differential protection device installed on the main node converter station. The invention can provide support for voltage stability, improve voltage quality, and when a fault occurs in a DC bus, the fault can be eliminated in time to ensure normal power supply.
Description
技术领域 technical field
本发明涉及电力技术领域，尤其涉及一种柔性直流闭环形智能配电网的母差保护方法及系统。 The present invention relates to the field of electric power technology, in particular to a bus differential protection method and system for a flexible DC closed-loop intelligent distribution network.
背景技术 Background technique
随着电力电子器件和控制技术的发展，出现了新型的半导体器件—绝缘栅双极晶体管（Insulated Gate Bipolar Transistor, IGBT）在低电压系统的应用，使得IGBT作为开关器件的电压源换流器（Voltage-Sourced Converter，VSC），随后在工业驱动装置上得到广泛应用，再经过随后的IGBT器件的电压和容量多次升级后，使得采用绝缘栅双极晶体管构成的电压源换流器在直流输配电网中应用成为现实。 With the development of power electronic devices and control technology, a new type of semiconductor device—Insulated Gate Bipolar Transistor (IGBT) has been applied in low-voltage systems, making IGBT a voltage source converter for switching devices ( Voltage-Sourced Converter, VSC), and then widely used in industrial drive devices, and after several upgrades of the voltage and capacity of subsequent IGBT devices, the voltage source converter composed of insulated gate bipolar transistors is used in DC transmission. The application in the distribution network becomes a reality.
在直流输配电网应用中换流器采用IGBT阀和两电平（或多电平）三相机构，并使用脉宽调制技术（Pulse Width Modulation，PWM）控制IGBT阀的开断状况，具备上述功能后使得由其构成的直流配电网系统在许多方面不同于常规的直流输配电，可以克服常规的直流输配电中呈现的多类问题。这种新型的直流输配电技术，简称为“柔性直流（High Voltage Direct Current Flexible，HVDC-Flexible）”。目前的柔性直流输电系统均以点对点为主，如图1所示。 In the application of DC transmission and distribution network, the converter adopts IGBT valve and two-level (or multi-level) three-phase mechanism, and uses pulse width modulation technology (Pulse Width Modulation, PWM) to control the opening and closing status of IGBT valve. After the function, the DC distribution network system composed of it is different from the conventional DC power transmission and distribution in many aspects, and can overcome many types of problems in the conventional DC power transmission and distribution. This new type of DC power transmission and distribution technology is referred to as "High Voltage Direct Current Flexible (HVDC-Flexible)". The current flexible DC transmission system is mainly based on point-to-point, as shown in Figure 1.
柔性直流（HVDC-Flexible）是从常规直流输配电技术发展而来，优点均为其常规直流输配电的优点，例如：柔性直流输配电线路相比于目前运行中交流输配电网线路要少一根导线，使其线路成本低，损耗小，节约了输配电线路大量走廊通道；柔性直流配电网系统为了实现较少故障率，一般采用电缆作为配电网系统通道，电缆的输送容量大、损耗小、使用周期长、输送距离不受限制；柔性直流配电网系统采用电缆作为输配电通道，一般在地下使用直埋技术，工程成本低、工期短，还减少对环境的影响；另外，柔性直流配电网系统稳定强；柔性直流配电网系统可以实现非同步系统的互联；柔性直流配电网系统所输送的有功功率和无功功率可以快速独立控制；柔性直流配电网系统较好地分期建设、扩展性好；事故后快速恢复供电和黑启动；可以向无源电网供电等等。 Flexible DC (HVDC-Flexible) is developed from conventional DC transmission and distribution technology, and its advantages are all the advantages of its conventional DC transmission and distribution. One less wire is needed to make the line cost low, the loss is small, and a large number of corridors of transmission and distribution lines are saved; in order to achieve a lower failure rate in the flexible DC distribution network system, cables are generally used as distribution network system channels. The transmission capacity is large, the loss is small, the service life is long, and the transmission distance is not limited; the flexible DC distribution network system uses cables as transmission and distribution channels, and generally uses direct burial technology underground, which has low engineering costs, short construction periods, and reduces environmental impact. In addition, the flexible DC distribution network system is stable and strong; the flexible DC distribution network system can realize the interconnection of non-synchronous systems; the active power and reactive power delivered by the flexible DC distribution network system can be quickly and independently controlled; The distribution network system is better constructed in stages and has good scalability; after the accident, it can quickly restore power supply and black start; it can supply power to the passive grid, etc.
但是，目前投运的柔性直流输电系统大多为双端系统，仅能实现点对点的直流功率转送。当有多回交流系统馈入时需要采取直流互联，需要多条直流输电线路；另外，有多用户，多再生能源（如风能、太阳能等）馈入时，该柔性直流输电系统的接口点不能满足需求。 However, most of the flexible DC transmission systems currently in operation are double-ended systems, which can only realize point-to-point DC power transfer. When there are multiple AC systems feeding in, DC interconnection is required, and multiple DC transmission lines are required; in addition, when there are multiple users and multiple renewable energy sources (such as wind energy, solar energy, etc.) feeding in, the interface points of the flexible DC transmission system cannot Meet the needs.
另外，当直流母线，含直流母线上的PT（Potential transformer，电压互感器）等设备出现故障时，无法及时查找到故障点，这将导致该柔性直流的配电网系统的供电可靠性大大降低。 In addition, when the DC bus, including PT (Potential transformer, voltage transformer) and other equipment on the DC bus, fails, the fault point cannot be found in time, which will greatly reduce the power supply reliability of the flexible DC distribution network system .
发明内容 Contents of the invention
为了解决目前投运的柔性直流配电网系统的接口点不能满足供电需求，以及在直流母线（含直流母线上的PT等设备）发生故障时，无法及时查找到故障点所导致的供电可靠性大大降低的技术问题，本发明提供一种柔性直流闭环形智能配电网的母差保护方法及系统，其可以为电压稳定提供支撑，提高电压质量，并且在直流母线发生故障时，可以及时排除故障，保证正常供电。 In order to solve the problem that the interface points of the flexible DC distribution network system currently in operation cannot meet the power supply requirements, and when the DC bus (including PT and other equipment on the DC bus) fails, the power supply reliability cannot be found in time. To greatly reduce the technical problems, the present invention provides a bus differential protection method and system for a flexible DC closed-loop intelligent distribution network, which can provide support for voltage stability, improve voltage quality, and can be eliminated in time when the DC bus fails. fault, ensure normal power supply.
本发明提供的一种柔性直流闭环形智能配电网的母差保护系统，包括： A bus differential protection system of a flexible DC closed-loop intelligent distribution network provided by the present invention includes:
N条直流母线和N条直流输电线路；每条直流母线与直流输电线路间隔相连，组成柔性直流闭环形智能配电网；N为大于等于3的自然数； N DC buses and N DC transmission lines; each DC bus is connected to DC transmission lines at intervals to form a flexible DC closed-loop intelligent distribution network; N is a natural number greater than or equal to 3;
其中，所述N条直流母线中的一条直流母线所在的区域为主节点换流站，其余直流母线所在的区域为子节点换流站； Wherein, the area where one of the N DC buses is located is the main node converter station, and the area where the other DC buses are located is the sub-node converter station;
所述每条直流母线上连接有至少一个用于将交流系统的电能整流成直流电能，汇入所述闭环形智能配电网的交流系统整流站；所述交流系统整流站一端通过直流互感器和直流开关与所述直流母线连接，另一端连接一交流系统； Each of the DC buses is connected to at least one AC system rectifier station for rectifying the electric energy of the AC system into DC electric energy, which is imported into the closed-loop intelligent distribution network; one end of the AC system rectifier station passes through a DC transformer and the DC switch are connected to the DC bus, and the other end is connected to an AC system;
所述每条直流母线上还连接有M个将直流电能逆变成交流电以供给用户使用的用户逆变站，每个所述用户逆变站均通过直流互感器和直流开关与所述直流母线连接；M为大于等于1的自然数； Each of the DC buses is also connected to M user inverter stations that invert DC power into AC power for use by users, and each of the user inverter stations is connected to the DC bus through a DC transformer and a DC switch. Connection; M is a natural number greater than or equal to 1;
所述每条直流母线上还连接有至少一个将采集到的直流母线高电压变换成二次电压的PT； Each of the DC buses is also connected to at least one PT that converts the collected DC bus high voltage into a secondary voltage;
所述柔性直流闭环形智能配电网的母差保护系统还包括：安装在所述主节点换流站上的母差保护装置； The bus differential protection system of the flexible DC closed-loop intelligent distribution network further includes: a bus differential protection device installed on the main node converter station;
所述主节点换流站和子节点换流站上的直流互感器采集其所在的直流母线的电流和电压信号，并汇集到所述母差保护装置； The DC transformers on the main node converter station and the sub-node converter stations collect the current and voltage signals of the DC bus where they are located, and collect them into the bus differential protection device;
所述母差保护装置根据来自所述主节点换流站和各个子节点换流站的电流和电压信号，判断是否存在不平衡电流，如是，则判断所述柔性直流闭环形智能配电网存在故障，如否，则判断柔性直流闭环形智能配电网正常工作。 The bus differential protection device judges whether there is an unbalanced current according to the current and voltage signals from the main node converter station and each sub-node converter station, and if so, judges that the flexible DC closed-loop intelligent distribution network exists fault, if not, it is judged that the flexible DC closed-loop smart distribution network is working normally.
其中，每条所述直流输电线路上设置有K台用于在所述直流输电线路有故障时跳闸将故障点进行隔离的直流开关；K为大于等于2的自然数。 Wherein, each of the direct current transmission lines is provided with K sets of direct current switches for tripping and isolating the fault point when the direct current transmission line is faulty; K is a natural number greater than or equal to 2.
其中，所述母差保护装置包括： Wherein, the bus differential protection device includes:
用于通过光纤通道采集所述主节点换流站上的直流互感器采集的电流和电压信号的主节点电流电压采集单元； A master node current and voltage acquisition unit for collecting current and voltage signals collected by the DC transformer on the master node converter station through a fiber optic channel;
多个用于通过光纤通道采集所述各个子节点换流站上的直流互感器采集的电流和电压信号的子节点电流电压采集单元； A plurality of sub-node current and voltage acquisition units for collecting current and voltage signals collected by the DC transformers on the sub-node converter stations through optical fiber channels;
与所述主节点电流电压采集单元连接，用于将其采集的到电流和电压信号转换成数字量的主节点电流电压转换单元； Connected with the master node current and voltage acquisition unit, a master node current and voltage conversion unit for converting the collected current and voltage signals into digital quantities;
多个与所述子节点电流电压采集单元连接，用于将其采集的到电流和电压信号转换成数字量的子节点电流电压转换单元； A plurality of sub-node current-voltage conversion units connected to the sub-node current and voltage acquisition unit for converting the collected current and voltage signals into digital quantities;
与所述主节点电流电压转换单元和各个子节点电流电压转换单元连接，用于对其转换而成的数字量进行求和计算比较的保护装置求和计算比较单元； A protection device summation calculation and comparison unit connected to the main node current-voltage conversion unit and each sub-node current-voltage conversion unit for summing calculation and comparison of the converted digital quantities;
与所述保护装置求和计算比较单元连接，用于根据保护装置求和计算比较单元的计算结果判断所述柔性直流闭环形智能配电网是否存在不平衡电流，并在判定所述柔性直流闭环形智能配电网存在不平衡电流时进行故障隔离处理的命令执行单元。 It is connected with the summation calculation and comparison unit of the protection device, and is used to judge whether there is an unbalanced current in the flexible DC closed-loop intelligent distribution network according to the calculation result of the summation calculation and comparison unit of the protection device, and determine whether the flexible DC closed-loop It is a command execution unit for fault isolation processing when there is unbalanced current in the intelligent distribution network.
其中，所述命令执行单元通过光纤通道与所述主节点换流站和子节点换流站连接。 Wherein, the command execution unit is connected to the main node converter station and the sub-node converter station through a fiber optic channel.
其中，每组直流母线区连接的交流系统整流站中，至少一个交流系统整流站作为用于控制直流电压的调压站。 Among the AC system rectifying stations connected to each group of DC bus area, at least one AC system rectifying station serves as a voltage regulating station for controlling the DC voltage.
相应的，本发明还提供了一种基于上述柔性直流闭环形智能配电网的母差保护系统的母差保护方法，所述柔性直流闭环形智能配电网的母差保护系统，包括： Correspondingly, the present invention also provides a bus differential protection method based on the bus differential protection system of the above-mentioned flexible DC closed-loop intelligent distribution network. The bus differential protection system of the flexible DC closed-loop intelligent distribution network includes:
N条直流母线和N条直流输电线路；每条直流母线与直流输电线路间隔相连，组成柔性直流闭环形智能配电网；N为大于等于3的自然数； N DC buses and N DC transmission lines; each DC bus is connected to DC transmission lines at intervals to form a flexible DC closed-loop intelligent distribution network; N is a natural number greater than or equal to 3;
其中，所述N条直流母线中的一条直流母线所在的区域为主节点换流站，其余直流母线所在的区域为子节点换流站； Wherein, the area where one of the N DC buses is located is the main node converter station, and the area where the other DC buses are located is the sub-node converter station;
所述每条直流母线上连接有至少一个用于将所述交流系统的电能整流成直流电能，汇入所述闭环形智能配电网的交流系统整流站；所述交流系统整流站一端通过直流互感器和直流开关与所述直流母线连接，另一端连接一交流系统； Each of the DC buses is connected to at least one AC system rectifier station for rectifying the electric energy of the AC system into DC electric energy and importing it into the closed-loop intelligent distribution network; one end of the AC system rectifier station passes through a DC The transformer and the DC switch are connected to the DC bus, and the other end is connected to an AC system;
所述每条直流母线上还连接有M个将直流电能逆变成交流电以供给用户使用的用户逆变站，所述每个用户逆变站均通过直流互感器和直流开关与所述直流母线连接；M为大于等于1的自然数； Each of the DC buses is also connected to M user inverter stations that invert the DC power into AC power for use by users, and each of the user inverter stations is connected to the DC bus through a DC transformer and a DC switch. Connection; M is a natural number greater than or equal to 1;
所述每条直流母线上还连接有至少一个将采集到的直流母线高电压变换成二次电压的PT； Each of the DC buses is also connected to at least one PT that converts the collected DC bus high voltage into a secondary voltage;
所述柔性直流闭环形智能配电网的母差保护系统还包括：安装在所述主节点换流站上的母差保护装置； The bus differential protection system of the flexible DC closed-loop intelligent distribution network further includes: a bus differential protection device installed on the main node converter station;
所述柔性直流闭环形智能配电网的母差保护系统的母差保护方法，包括： The bus differential protection method of the bus differential protection system of the flexible DC closed-loop intelligent distribution network includes:
所述主节点换流站和子节点换流站上的直流互感器采集其所在的直流母线的电流和电压信号，并汇集到所述母差保护装置； The DC transformers on the main node converter station and the sub-node converter stations collect the current and voltage signals of the DC bus where they are located, and collect them into the bus differential protection device;
所述母差保护装置根据来自所述主节点换流站和各个子节点换流站的电流和电压信号，判断是否存在不平衡电流； The bus differential protection device judges whether there is an unbalanced current according to the current and voltage signals from the master node converter station and each slave node converter station;
如存在不平衡电流，则母差保护装置判断所述柔性直流闭环形智能配电网存在故障； If there is an unbalanced current, the bus differential protection device judges that there is a fault in the flexible DC closed-loop intelligent distribution network;
如不存在不平衡电流，则母差保护装置判断柔性直流闭环形智能配电网正常工作。 If there is no unbalanced current, the bus differential protection device judges that the flexible DC closed-loop intelligent distribution network is working normally.
其中，所述母差保护装置根据来自所述主节点换流站和各个子节点换流站的电流和电压信号，判断是否存在不平衡电流，包括： Wherein, the bus differential protection device judges whether there is an unbalanced current according to the current and voltage signals from the main node converter station and each sub-node converter station, including:
所述母差保护装置的主节点电流电压采集单元通过光纤通道采集所述主节点换流站上的直流互感器采集的电流和电压信号； The main node current and voltage acquisition unit of the bus differential protection device collects the current and voltage signals collected by the DC transformer on the main node converter station through a fiber optic channel;
所述母差保护装置的多个子节点电流电压采集单元通过光纤通道采集所述各个子节点换流站上的直流互感器采集的电流和电压信号； The multiple sub-node current and voltage acquisition units of the bus differential protection device collect the current and voltage signals collected by the DC transformers on the converter stations of the respective sub-nodes through fiber optic channels;
所述母差保护装置的主节点电流电压转换单元将所述主节点电流电压采集单元其采集的到电流和电压信号转换成数字量； The main node current and voltage conversion unit of the bus differential protection device converts the current and voltage signals collected by the main node current and voltage acquisition unit into digital quantities;
所述母差保护装置的子节点电流电压转换单元将子节点电流电压转换单元采集的到电流和电压信号转换成数字量； The sub-node current-voltage conversion unit of the bus differential protection device converts the current and voltage signals collected by the sub-node current-voltage conversion unit into digital quantities;
所述母差保护装置的求和计算比较单元对所述主节点电流电压转换单元和子节点电流电压转换单元转换而成的数字量进行求和计算比较； The summation calculation and comparison unit of the bus differential protection device performs summation calculation and comparison on the digital quantities converted by the master node current-voltage conversion unit and the sub-node current-voltage conversion unit;
所述母差保护装置的命令执行单元根据所述保护装置求和计算比较单元的计算结果判断所述柔性直流闭环形智能配电网是否存在不平衡电流，并在判定所述柔性直流闭环形智能配电网存在不平衡电流时进行故障隔离处理。 The command execution unit of the bus differential protection device judges whether there is an unbalanced current in the flexible DC closed-loop intelligent distribution network according to the calculation result of the summation calculation and comparison unit of the protection device, and determines whether the flexible DC closed-loop intelligent distribution network has an unbalanced current. Fault isolation processing is performed when there is an unbalanced current in the distribution network.
实施本发明，具有如下有益效果： Implement the present invention, have following beneficial effect:
本发明提供的一种柔性直流闭环形智能配电网的母差保护方法及系统，其通过闭环形设计，解决了现有技术中点对点的柔性直流配电网存在的接口点不能满足需求的技术问题；并且将该柔性直流闭环形智能配电网中的一条直流母线所在的区域作为主节点换流站，其余作为子节点换流站，在主节点换流站上安装有母差保护装置，根据采集到的主节点换流站和子节点换流站上的电流和电压进行故障判断，可以有效而快捷的进行故障排除。 The present invention provides a bus differential protection method and system for a flexible DC closed-loop intelligent distribution network. Through the closed-loop design, it solves the problem that the interface points in the point-to-point flexible DC distribution network in the prior art cannot meet the requirements. problem; and the area where a DC bus in the flexible DC closed-loop intelligent distribution network is located is the main node converter station, and the rest are used as sub-node converter stations, and a bus differential protection device is installed on the main node converter station. According to the collected current and voltage of the main node converter station and the sub-node converter station, the fault judgment can be carried out effectively and quickly.
附图说明 Description of drawings
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动性的前提下，还可以根据这些附图获得其他的附图。 In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings without any creative effort.
图1为现有技术的点对点柔性直流输电系统的示意图； FIG. 1 is a schematic diagram of a point-to-point flexible direct current transmission system in the prior art;
图2为本发明提供的柔性直流闭环形智能配电网的结构示意图； Fig. 2 is a schematic structural diagram of a flexible DC closed-loop intelligent distribution network provided by the present invention;
图3为本发明提供的柔性直流闭环形智能配电网的直流母线区的结构示意图； Fig. 3 is a schematic structural diagram of the DC bus area of the flexible DC closed-loop intelligent distribution network provided by the present invention;
图4为本发明提供的柔性直流闭环形智能配电网的母差保护系统实施例一的结构示意图； Fig. 4 is a schematic structural diagram of Embodiment 1 of the bus differential protection system of the flexible DC closed-loop intelligent distribution network provided by the present invention;
图6为本发明提供的柔性直流闭环形智能配电网的母差保护系统实施例二的结构示意图； Fig. 6 is a schematic structural diagram of Embodiment 2 of the bus differential protection system of the flexible DC closed-loop intelligent distribution network provided by the present invention;
图7为本发明提供的柔性直流闭环形智能配电网的母差保护方法实施例一的结构示意图； Fig. 7 is a schematic structural diagram of Embodiment 1 of the bus differential protection method of the flexible DC closed-loop intelligent distribution network provided by the present invention;
图8为本发明提供的柔性直流闭环形智能配电网的母差保护方法实施例二的结构示意图。 Fig. 8 is a schematic structural diagram of Embodiment 2 of the bus differential protection method of the flexible DC closed-loop intelligent distribution network provided by the present invention.
具体实施方式 Detailed ways
为了解决目前投运的柔性直流配电网系统的接口点不能满足供电需求，以及在直流母线（含直流母线上的PT等设备）发生故障时，无法及时查找到故障点所导致的供电可靠性大大降低的技术问题，本发明提供一种柔性直流闭环形智能配电网的母差保护方法及系统，其可以为电压稳定提供支撑，提高电压质量，并且在直流母线发生故障时，可以及时排除故障，保证正常供电。 In order to solve the problem that the interface points of the flexible DC distribution network system currently in operation cannot meet the power supply requirements, and when the DC bus (including PT and other equipment on the DC bus) fails, the power supply reliability cannot be found in time. To greatly reduce the technical problems, the present invention provides a bus differential protection method and system for a flexible DC closed-loop intelligent distribution network, which can provide support for voltage stability, improve voltage quality, and can be eliminated in time when the DC bus fails. fault, ensure normal power supply.
本发明提供的一种柔性直流闭环形智能配电网的母差保护系统，包括： A bus differential protection system of a flexible DC closed-loop intelligent distribution network provided by the present invention includes:
N条直流母线和N条直流输电线路；每条直流母线与直流输电线路间隔相连，组成柔性直流闭环形智能配电网；N为大于等于3的自然数； N DC buses and N DC transmission lines; each DC bus is connected to DC transmission lines at intervals to form a flexible DC closed-loop intelligent distribution network; N is a natural number greater than or equal to 3;
其中，所述N条直流母线中的一条直流母线所在的区域为主节点换流站，其余直流母线所在的区域为子节点换流站； Wherein, the area where one of the N DC buses is located is the main node converter station, and the area where the other DC buses are located is the sub-node converter station;
所述每条直流母线上连接有至少一个用于将所述交流系统的电能整流成直流电能，汇入所述闭环形智能配电网的交流系统整流站；所述交流系统整流站一端通过直流互感器和直流开关与所述直流母线连接，另一端连接一交流系统； Each of the DC buses is connected to at least one AC system rectifier station for rectifying the electric energy of the AC system into DC electric energy and importing it into the closed-loop intelligent distribution network; one end of the AC system rectifier station passes through a DC The transformer and the DC switch are connected to the DC bus, and the other end is connected to an AC system;
其中，所述每组直流母线区连接的交流系统整流站中，至少一个交流系统整流站作为用于控制直流电压的调压站。 Wherein, among the AC system rectifying stations connected to each group of DC bus areas, at least one AC system rectifying station serves as a voltage regulating station for controlling DC voltage.
所述每条直流母线上还连接有M个将直流电能逆变成交流电以供给用户使用的用户逆变站，所述每个用户逆变站均通过直流互感器和直流开关与所述直流母线连接；M为大于等于1的自然数； Each of the DC buses is also connected to M user inverter stations that invert the DC power into AC power for use by users, and each of the user inverter stations is connected to the DC bus through a DC transformer and a DC switch. Connection; M is a natural number greater than or equal to 1;
所述每条直流母线上还连接有至少一个将采集到的直流母线高电压变换成二次电压的PT； Each of the DC buses is also connected to at least one PT that converts the collected DC bus high voltage into a secondary voltage;
所述柔性直流闭环形智能配电网的母差保护系统还包括：安装在所述主节点换流站上的母差保护装置； The bus differential protection system of the flexible DC closed-loop intelligent distribution network further includes: a bus differential protection device installed on the main node converter station;
所述主节点换流站和子节点换流站上的直流互感器采集其所在的直流母线的电流和电压信号，并汇集到所述母差保护装置； The DC transformers on the main node converter station and the sub-node converter stations collect the current and voltage signals of the DC bus where they are located, and collect them into the bus differential protection device;
所述母差保护装置根据来自所述主节点换流站和各个子节点换流站的电流和电压信号，判断是否存在不平衡电流，如是，则判断所述柔性直流闭环形智能配电网存在故障，如否，则判断柔性直流闭环形智能配电网正常工作。 The bus differential protection device judges whether there is an unbalanced current according to the current and voltage signals from the main node converter station and each sub-node converter station, and if so, judges that the flexible DC closed-loop intelligent distribution network exists fault, if not, it is judged that the flexible DC closed-loop smart distribution network is working normally.
其中，所述每条直流输电线路上设置有K台用于在所述直流输电线路有故障时跳闸将故障点进行隔离的直流开关；K为大于等于2的自然数。 Wherein, each DC transmission line is provided with K sets of DC switches for tripping and isolating the fault point when the DC transmission line is faulty; K is a natural number greater than or equal to 2.
其中，所述母差保护装置包括： Wherein, the bus differential protection device includes:
用于通过光纤通道采集所述主节点换流站上的直流互感器采集的电流和电压信号的主节点电流电压采集单元； A master node current and voltage acquisition unit for collecting current and voltage signals collected by the DC transformer on the master node converter station through a fiber optic channel;
多个用于通过光纤通道采集所述各个子节点换流站上的直流互感器采集的电流和电压信号的子节点电流电压采集单元； A plurality of sub-node current and voltage acquisition units for collecting current and voltage signals collected by the DC transformers on the sub-node converter stations through optical fiber channels;
与所述主节点电流电压采集单元连接，用于将其采集的到电流和电压信号转换成数字量的主节点电流电压转换单元； Connected with the master node current and voltage acquisition unit, a master node current and voltage conversion unit for converting the collected current and voltage signals into digital quantities;
多个与所述子节点电流电压采集单元连接，用于将其采集的到电流和电压信号转换成数字量的子节点电流电压转换单元； A plurality of sub-node current-voltage conversion units connected to the sub-node current and voltage acquisition unit for converting the collected current and voltage signals into digital quantities;
与所述主节点电流电压转换单元和各个子节点电流电压转换单元连接，用于对其转换而成的数字量进行求和计算比较的保护装置求和计算比较单元； A protection device summation calculation and comparison unit connected to the main node current-voltage conversion unit and each sub-node current-voltage conversion unit for summing calculation and comparison of the converted digital quantities;
与所述保护装置求和计算比较单元连接，用于根据保护装置求和计算比较单元的计算结果判断所述柔性直流闭环形智能配电网是否存在不平衡电流，并在判定所述柔性直流闭环形智能配电网存在不平衡电流时进行故障隔离处理的命令执行单元。 It is connected with the summation calculation and comparison unit of the protection device, and is used to judge whether there is an unbalanced current in the flexible DC closed-loop intelligent distribution network according to the calculation result of the summation calculation and comparison unit of the protection device, and determine whether the flexible DC closed-loop It is a command execution unit for fault isolation processing when there is unbalanced current in the intelligent distribution network.
其中，所述命令执行单元通过光纤通道与所述主节点换流站和子节点换流站连接。 Wherein, the command execution unit is connected to the main node converter station and the sub-node converter station through a fiber optic channel.
实施本发明，具有如下有益效果： Implement the present invention, have following beneficial effect:
本发明提供的一种柔性直流闭环形智能配电网的母差保护系统，其通过闭环形设计，解决了现有技术中点对点的柔性直流配电网存在的接口点不能满足需求的技术问题；并且将该柔性直流闭环形智能配电网中的一条直流母线所在的区域作为主节点换流站，其余作为子节点换流站，在主节点换流站上安装有母差保护装置，根据采集到的主节点换流站和子节点换流站上的电流和电压进行故障判断，可以有效而快捷的进行故障排除。 The bus differential protection system of a flexible DC closed-loop intelligent distribution network provided by the present invention solves the technical problem that the interface points in the point-to-point flexible DC distribution network in the prior art cannot meet the requirements through the closed-loop design; And the area where one DC bus in the flexible DC closed-loop intelligent distribution network is located is used as the main node converter station, and the rest are used as sub-node converter stations. A bus differential protection device is installed on the main node converter station. According to the collected The current and voltage on the main node converter station and the sub-node converter station can be used for fault judgment, which can effectively and quickly carry out troubleshooting.
以下将举例详细说明本发明提供的一种柔性直流闭环形智能配电网的母差保护系统的具体结构。 The specific structure of a bus differential protection system of a flexible DC closed-loop intelligent distribution network provided by the present invention will be described in detail below with examples.
首先请参见图2，为本发明提供的一种柔性直流闭环形智能配电网的结构示意图，该实施例为尚未为该配电网配置母差保护装置的示意图。 First, please refer to Fig. 2 , which is a schematic structural diagram of a flexible DC closed-loop intelligent distribution network provided by the present invention, and this embodiment is a schematic diagram of a bus differential protection device not yet configured for the distribution network.
图2所示的一种柔性直流闭环形智能配电网，其是以3条直流母线和3条直流输电线路构成“手拉手”的闭环形智能配电网进行说明的。 A flexible DC closed-loop intelligent distribution network shown in Fig. 2 is described by using three DC buses and three DC transmission lines to form a "hand in hand" closed-loop intelligent distribution network.
具体的，图2所示的基于柔性直流的闭环形智能配电网系统包括： Specifically, the flexible DC-based closed-loop smart distribution network system shown in Figure 2 includes:
3条直流母线，分别是：直流母线1、直流母线2、直流母线3；3条直流输电线路，分别是直流输电线路1、直流输电线路2、直流输电线路3； 3 DC buses, respectively: DC bus 1, DC bus 2, and DC bus 3; 3 DC transmission lines, respectively DC transmission line 1, DC transmission line 2, and DC transmission line 3;
该闭环形智能配电网系统还至少包括：6台直流开关（QF1、QF2、QF3、QF4、QF5、QF6），当然视具体情况，每条直流输电线路上设置的直流开关可以不止两个；至少包括3台交流系统整流站(或调压站)，分别为交流系统整流站(或调压站)1、交流系统整流站(或调压站)2、交流系统整流站(或调压站)3； The closed-loop intelligent distribution network system also includes at least 6 DC switches (QF1, QF2, QF3, QF4, QF5, QF6). Of course, depending on the specific circumstances, there may be more than two DC switches on each DC transmission line; Including at least 3 AC system rectification stations (or voltage regulation stations), respectively AC system rectification station (or voltage regulation station) 1, AC system rectification station (or voltage regulation station) 2, AC system rectification station (or voltage regulation station) )3;
另外，各直流母线上有M台用户逆变站，具体的：直流母线1上有用户逆变站1-1…1- m；直流母线2上有用户逆变站2-1… 2-n；直流母线3上有用户逆变站3-1… 3-m； In addition, there are M user inverter stations on each DC bus, specifically: there are user inverter stations 1-1...1-m on DC bus 1; there are user inverter stations 2-1...2-n on DC bus 2 ; There are user inverter stations 3-1... 3-m on the DC bus 3;
该闭环形智能配电网系统中各个部件的作用如下： The functions of each component in the closed-loop intelligent distribution network system are as follows:
直流母线1、直流母线2、直流母线3的作用主要通过直流输电线路构成“手拉手”的闭环形智能配电网，同时连接各交流系统整流站(或调压站)，起到汇集电能的作用。 The functions of DC bus 1, DC bus 2, and DC bus 3 are mainly to form a "hand in hand" closed-loop intelligent distribution network through DC transmission lines, and connect each AC system rectifier station (or voltage regulation station) at the same time to play the role of collecting electric energy. effect.
直流输电线路1、直流输电线路2、直流输电线路3的作用将各条直流母线1、直流母线2、直流母线3连接在一起，实现电能输送和电能均匀分配。 The function of DC transmission line 1, DC transmission line 2, and DC transmission line 3 is to connect each DC bus 1, DC bus 2, and DC bus 3 together to realize power transmission and uniform distribution of power.
直流输电线路上设置的直流开关（QF1、QF2、QF3、QF4、QF5、QF6）作用主要当各条直流输电线路（1、2、3）有故障时跳闸将故障点进行隔离. The DC switches (QF1, QF2, QF3, QF4, QF5, QF6) installed on the DC transmission line are mainly used to trip and isolate the fault point when each DC transmission line (1, 2, 3) is faulty.
如图2中直流输电线路1上d1点故障，该直流输电线路1的保护动作跳开两侧的直流开关（QF1、QF2），即可实现故障隔离。 As shown in Figure 2, point d1 on the DC transmission line 1 is faulty, and the protection action of the DC transmission line 1 trips the DC switches (QF1, QF2) on both sides to realize fault isolation.
直流母线上设置的各台用户逆变站作用主要将直流电能通过逆变技术逆变成用户所需要的交流电供给使用。 The function of each user inverter station set on the DC bus is mainly to invert the DC power into the AC power required by the user through the inverter technology for supply and use.
交流系统整流站(或调压站) 主要作用是将交流系统的电能通过整流技术整流成直流电能，汇入柔性直流的闭环形智能配电网系统，实现电能分配；在柔性直流的闭环形智能配电网系统至少有1个交流系统整流站充当调压站，作用主要是控制直流电压，起到平衡系统直流电压功能。 The main function of the AC system rectifier station (or voltage regulating station) is to rectify the power of the AC system into DC power through rectification technology, and then import it into the flexible DC closed-loop intelligent distribution network system to realize power distribution; in the flexible DC closed-loop intelligent The distribution network system has at least one AC system rectifier station as a voltage regulating station, whose main function is to control the DC voltage and balance the DC voltage of the system.
交流系统1、交流系统2、交流系统3的主要作用提供电能。 The main function of AC system 1, AC system 2, and AC system 3 is to provide electric energy.
需要说明的是，直流母线和直流输电线路的条数还可以是4、5、6、7等其他数量；每条直流母线上的交流系统整流站（调压站）、交流系统、以及用户逆变器的数量也可以进行灵活的设置；每条直流输电线路上的直流开关数量也可以设置成不同的数值。 It should be noted that the number of DC busbars and DC transmission lines can also be 4, 5, 6, 7 and other numbers; The number of transformers can also be flexibly set; the number of DC switches on each DC transmission line can also be set to different values.
图2所示的柔性直流闭环形智能配电网系统换流站其主要特点是利用直流母线作为汇总及输送电能的环节，可以解决多用户、多再生能源（如风能、太阳能等）馈入时接口点需求，也具有增强提高供电可靠性等多方面的优点。 The main feature of the converter station of the flexible DC closed-loop intelligent distribution network system shown in Figure 2 is that the DC bus is used as a link to collect and transmit electric energy, which can solve the problem of multi-user and multi-renewable energy (such as wind energy, solar energy, etc.) It also has many advantages such as enhancing the reliability of power supply and so on.
进一步的，为了避免在直流母线（含直流母线上的PT等设备）发生故障时，无法及时查找到故障点所导致的供电可靠性大大降低的技术问题，本发明提供一种柔性直流闭环形智能配电网的母差保护系统，其可以为电压稳定提供支撑，提高电压质量，并且在直流母线发生故障时（例如图2所示的直流母线区1出现故障点d2），可以及时排除故障，保证正常供电。 Furthermore, in order to avoid the technical problem of greatly reducing the reliability of power supply caused by the failure to find the fault point in time when the DC bus (including PT and other equipment on the DC bus) fails, the present invention provides a flexible DC closed-loop intelligent The bus differential protection system of the distribution network can provide support for voltage stability, improve voltage quality, and when the DC bus fails (such as the fault point d2 in the DC bus area 1 shown in Figure 2), it can eliminate the fault in time. Ensure normal power supply.
参见图3，为本发明提供的本发明提供的柔性直流闭环形智能配电网的母差保护系统的直流母线区的结构示意图。 Referring to FIG. 3 , it is a schematic structural diagram of the DC bus area of the bus differential protection system of the flexible DC closed-loop intelligent distribution network provided by the present invention.
如图3所示，本实施例一提供的柔性直流闭环形智能配电网的母差保护系统首先对如图2所示的柔性直流闭环形智能配电网的直流母线区进行配置，以图2中的一条直流母线1所在的直流母线区1为例进行说明，如下： As shown in Figure 3, the bus differential protection system of the flexible DC closed-loop intelligent distribution network provided by the first embodiment first configures the DC bus area of the flexible DC closed-loop intelligent distribution network shown in Figure 2, as shown in Figure 2 Take the DC bus area 1 where a DC bus 1 in 2 is located as an example to illustrate, as follows:
该直流母线上设置有至少1台以上交流系统整流站；以及至少1以上用户侧逆变站（如图3中有N台），还设置有直流开关1、直流开关2及直流开关N；以及直流互感器1、直流互感2及直流互感器N；另，该直流母线上还设置有1台PT。 The DC bus is provided with at least one AC system rectifier station; and at least one user-side inverter station (as shown in Figure 3, there are N stations), and a DC switch 1, a DC switch 2, and a DC switch N; and DC transformer 1, DC transformer 2 and DC transformer N; in addition, a PT is also arranged on the DC bus.
该直流母线以及其上设置的以上元件的作用如下： The functions of the DC busbar and the above components arranged on it are as follows:
直流母线作用主要通过直流输电线路构成“手拉手”的闭环形智能配电网，同时连接各交流系统整流站(或调压站)，起到汇集电能； The role of the DC bus is mainly to form a "hand in hand" closed-loop intelligent distribution network through the DC transmission line, and at the same time connect each AC system rectifier station (or voltage regulation station) to collect electric energy;
直流开关1-N的作用主要是当有故障时跳闸将故障点进行隔离作用； The function of DC switch 1-N is mainly to trip and isolate the fault point when there is a fault;
PT主要将采集到直流母线高电压按照要求变换成保护需要的二次电压； PT mainly converts the collected DC bus high voltage into the secondary voltage required for protection according to requirements;
直流互感器1、直流互感器2及直流互感器N主要作用是采集各支路的电流按照要求变换成保护需要的二次电流；其中，这些直流互感器均为光电流互感器，采集的信号是以光的方式通过光纤传输。 The main function of DC transformer 1, DC transformer 2 and DC transformer N is to collect the current of each branch and transform it into the secondary current required for protection according to the requirements; among them, these DC transformers are photocurrent transformers, and the collected signals It is transmitted through optical fiber in the form of light.
需要说明的是，图3中直流母线示意图及其所涉及的元件在内属于闭环形智能配电网系统其中1个换流站。 It should be noted that the schematic diagram of the DC bus in Figure 3 and the components involved belong to one of the converter stations in the closed-loop intelligent distribution network system.
图3中直流母线示意图只是闭环形智能配电网系统1个节点上的母线，其他节点上的直流母线的设置相同，在此不再赘述。 The schematic diagram of the DC bus in Figure 3 is only the bus on one node of the closed-loop intelligent distribution network system, and the settings of the DC bus on other nodes are the same, so it will not be repeated here.
对于本发明提供的柔性直流闭环形智能配电网系统，可以将其理解为大节点，而图3中直流母线可以理解为一个子节点。图2所示的本发明中的柔性直流闭环形智能配电网可以理解为大差保护，用于判断闭环形智能配电网系统是否存在故障；而图3所示的直流母线可以理解为小差保护，用于判断闭环形智能配电网系统具体故障母线。本发明提供的基于柔性直流闭环形智能配电网系统母差保护系统由大差保护和小差保护构成。 For the flexible DC closed-loop intelligent distribution network system provided by the present invention, it can be understood as a large node, and the DC bus in Figure 3 can be understood as a sub-node. The flexible DC closed-loop intelligent distribution network of the present invention shown in Figure 2 can be understood as a large difference protection, which is used to judge whether there is a fault in the closed-loop intelligent distribution network system; and the DC bus shown in Figure 3 can be understood as a small difference Protection, which is used to judge the specific fault bus of the closed-loop intelligent distribution network system. The bus differential protection system based on the flexible DC closed-loop intelligent distribution network system provided by the present invention is composed of large differential protection and small differential protection.
本发明提出的柔性直流的闭环形智能配电网母差保护系统涉及的各母线分散在不同地方特点，因此可以选择柔性直流闭环形智能配电网中的1个换流站为主节点换流站，如选择图2所示的柔性直流的闭环形智能配电网的直流母线1作为主节点换流站，在其上安装一个母差保护装置，即可构成本发明提供的柔性直流闭环形智能配电网母差保护系统，具体如图4所示，当然图4中的各段直流母线均如图3那样设置有直流互感器和直流开关等，为直观起见，图4中并未详细示出，本领域普通技术人员应当理解，其各个直流母线段所在的直流母线区均如图3那样设置。 The buses involved in the flexible DC closed-loop intelligent distribution network bus differential protection system proposed by the present invention are scattered in different places, so one converter station in the flexible DC closed-loop intelligent distribution network can be selected as the main node for commutation Station, such as selecting the DC bus 1 of the flexible DC closed-loop intelligent distribution network shown in Figure 2 as the main node converter station, and installing a bus differential protection device on it, the flexible DC closed-loop provided by the present invention can be formed. The intelligent distribution network bus differential protection system is specifically shown in Figure 4. Of course, each section of the DC bus in Figure 4 is equipped with DC transformers and DC switches, etc., as shown in Figure 3. As shown, those of ordinary skill in the art should understand that the DC bus area where each DC bus section is located is set as shown in FIG. 3 .
具体的，母差保护装置具体结构如图5所示： Specifically, the specific structure of the bus differential protection device is shown in Figure 5:
本实施例中的母差保护装置包括： The bus differential protection device in this embodiment includes:
用于通过光纤通道采集所述主节点换流站上的直流互感器采集的电流和电压信号的主节点电流电压采集单元； A master node current and voltage acquisition unit for collecting current and voltage signals collected by the DC transformer on the master node converter station through a fiber optic channel;
多个用于通过光纤通道采集所述各个子节点换流站上的直流互感器采集的电流和电压信号的子节点电流电压采集单元； A plurality of sub-node current and voltage acquisition units for collecting current and voltage signals collected by the DC transformers on the sub-node converter stations through optical fiber channels;
与所述主节点电流电压采集单元连接，用于将其采集的到电流和电压信号转换成数字量的主节点电流电压转换单元； Connected with the master node current and voltage acquisition unit, a master node current and voltage conversion unit for converting the collected current and voltage signals into digital quantities;
多个与所述子节点电流电压采集单元连接，用于将其采集的到电流和电压信号转换成数字量的子节点电流电压转换单元； A plurality of sub-node current-voltage conversion units connected to the sub-node current and voltage acquisition unit for converting the collected current and voltage signals into digital quantities;
与所述主节点电流电压转换单元和各个子节点电流电压转换单元连接，用于对其转换而成的数字量进行求和计算比较的保护装置求和计算比较单元； A protection device summation calculation and comparison unit connected to the main node current-voltage conversion unit and each sub-node current-voltage conversion unit for summing calculation and comparison of the converted digital quantities;
与所述保护装置求和计算比较单元连接，用于根据保护装置求和计算比较单元的计算结果判断所述柔性直流闭环形智能配电网是否存在不平衡电流，并在判定所述柔性直流闭环形智能配电网存在不平衡电流时进行故障隔离处理的命令执行单元。 It is connected with the summation calculation and comparison unit of the protection device, and is used to judge whether there is an unbalanced current in the flexible DC closed-loop intelligent distribution network according to the calculation result of the summation calculation and comparison unit of the protection device, and determine whether the flexible DC closed-loop It is a command execution unit for fault isolation processing when there is unbalanced current in the intelligent distribution network.
其中，所述命令执行单元通过光纤通道与所述主节点换流站和子节点换流站连接。 Wherein, the command execution unit is connected to the main node converter station and the sub-node converter station through a fiber optic channel.
另外，母差保护装置还可以包括：信息打印输出单元、人机对话单元等等，其作用分别如下： In addition, the bus differential protection device can also include: an information printout unit, a man-machine dialogue unit, etc., and their functions are as follows:
信息打印输出单元用于对保护动作等进行打印。 The information printout unit is used to print protection actions, etc.
人机对话单元用于对定值修改及状态查看等。 The man-machine dialogue unit is used to modify the fixed value and view the status, etc.
图6为本发明提供的一种柔性直流闭环形智能配电网的母差保护系统实施例二的结构示意图。 Fig. 6 is a schematic structural diagram of Embodiment 2 of a bus differential protection system of a flexible DC closed-loop intelligent distribution network provided by the present invention.
上述实施例中的柔性直流闭环形智能配电网的母差保护系统仅是一个单闭环形智能配电网系统，可以根据城市发展的需要扩展成多闭环形互相连接智能配电网系统（一环、二环……N环），其中，每一环的闭环形智能配电网之间通过直流联络线路连接，以便增强输送电的能力。具体如图6所示，其中，为了简便起见，对于直流母线区的配置以及每一环上连接的母差保护装置并未示出，本领域普通技术人员应当理解，其中每一环上都连接有母差保护装置，并且其直流母线区均如图3中那样设置。 The bus differential protection system of the flexible DC closed-loop intelligent distribution network in the above embodiment is only a single closed-loop intelligent distribution network system, which can be expanded into a multi-closed-loop interconnected intelligent distribution network system according to the needs of urban development (one ring, second ring...N ring), in which, the closed-loop intelligent distribution network of each ring is connected by a DC connection line in order to enhance the ability of power transmission. Specifically as shown in Figure 6, where, for the sake of simplicity, the configuration of the DC bus area and the bus protection device connected to each ring are not shown, those of ordinary skill in the art should understand that each ring is connected There is a bus differential protection device, and its DC bus area is set as shown in Figure 3.
相应的，本发明还提供了一种基于上述柔性直流闭环形智能配电网的母差保护系统的母差保护方法。 Correspondingly, the present invention also provides a bus differential protection method based on the bus differential protection system of the flexible direct current closed-loop intelligent distribution network.
如图7所示，本发明提供的柔性直流闭环形智能配电网的母差保护系统的母差保护方法，包括： As shown in Figure 7, the bus differential protection method of the bus differential protection system of the flexible DC closed-loop intelligent distribution network provided by the present invention includes:
步骤100，主节点换流站和子节点换流站上的直流互感器采集其所在的直流母线的电流和电压信号，并汇集到所述母差保护装置； Step 100, the DC transformers on the master node converter station and the slave node converter station collect the current and voltage signals of the DC bus where they are located, and collect them into the bus differential protection device;
步骤101，母差保护装置根据来自所述主节点换流站和各个子节点换流站的电流和电压信号，判断是否存在不平衡电流； Step 101, the bus differential protection device judges whether there is an unbalanced current according to the current and voltage signals from the master node converter station and each slave node converter station;
步骤102，如存在不平衡电流，则母差保护装置判断所述柔性直流闭环形智能配电网存在故障； Step 102, if there is an unbalanced current, the bus differential protection device judges that there is a fault in the flexible DC closed-loop intelligent distribution network;
步骤103，如不存在不平衡电流，则母差保护装置判断柔性直流闭环形智能配电网正常工作。 Step 103, if there is no unbalanced current, the bus differential protection device judges that the flexible DC closed-loop smart distribution network is working normally.
如图8所示，母差保护装置根据来自所述主节点换流站和各个子节点换流站的电流和电压信号，判断是否存在不平衡电流的步骤，包括： As shown in Fig. 8, the bus differential protection device judges whether there is an unbalanced current according to the current and voltage signals from the main node converter station and each sub-node converter station, including:
步骤200，母差保护装置的主节点电流电压采集单元通过光纤通道采集所述主节点换流站上的直流互感器采集的电流和电压信号； Step 200, the main node current and voltage acquisition unit of the bus differential protection device collects the current and voltage signals collected by the DC transformer on the main node converter station through the optical fiber channel;
步骤201，母差保护装置的多个子节点电流电压采集单元通过光纤通道采集所述各个子节点换流站上的直流互感器采集的电流和电压信号； Step 201, the multiple sub-node current and voltage acquisition units of the bus differential protection device collect the current and voltage signals collected by the DC transformers on the converter stations of the respective sub-nodes through the optical fiber channel;
步骤202，母差保护装置的主节点电流电压转换单元将所述主节点电流电压采集单元其采集的到电流和电压信号转换成数字量； Step 202, the main node current and voltage conversion unit of the bus differential protection device converts the current and voltage signals collected by the main node current and voltage acquisition unit into digital quantities;
步骤203，母差保护装置的子节点电流电压转换单元将子节点电流电压转换单元采集的到电流和电压信号转换成数字量； Step 203, the sub-node current-voltage conversion unit of the bus differential protection device converts the current and voltage signals collected by the sub-node current-voltage conversion unit into digital quantities;
步骤204，母差保护装置的求和计算比较单元对所述主节点电流电压转换单元和子节点电流电压转换单元转换而成的数字量进行求和计算比较； Step 204, the summation calculation and comparison unit of the bus differential protection device performs summation calculation and comparison on the digital quantities converted by the master node current-voltage conversion unit and the sub-node current-voltage conversion unit;
步骤205，母差保护装置的命令执行单元根据所述保护装置求和计算比较单元的计算结果判断所述柔性直流闭环形智能配电网是否存在不平衡电流，并在判定所述柔性直流闭环形智能配电网存在不平衡电流时进行故障隔离处理。 Step 205, the command execution unit of the bus differential protection device judges whether there is an unbalanced current in the flexible DC closed-loop intelligent distribution network according to the calculation result of the summation calculation and comparison unit of the protection device, and determines whether the flexible DC closed-loop intelligent distribution network has an unbalanced current. Fault isolation processing is performed when there is an unbalanced current in the smart distribution network.
本发明提供的柔性直流闭环形智能配电网的母差保护系统的母差保护方法的具体应用如下： The specific application of the bus differential protection method of the bus differential protection system of the flexible DC closed-loop intelligent distribution network provided by the present invention is as follows:
柔性直流闭环形智能配电网各子节点换流站通过直流互感器采集电流量。同时主节点换流站通过直流电流互感器采集电流量。 The converter station of each sub-node of the flexible DC closed-loop intelligent distribution network collects the current through the DC transformer. At the same time, the master node converter station collects the current through the DC current transformer.
将闭环形智能配电网系统各小节点换流站通过直流电流互感器采集电流量汇集到主节点换流站上连接的母差保护装置进行计算和比较。 The current collected by each small node converter station of the closed-loop intelligent distribution network system through the DC current transformer is collected to the bus differential protection device connected to the main node converter station for calculation and comparison.
如果闭环形智能配电网内发生故障，主节点换流站连接的母差保护装置的大差保护感应到不平衡电流，并且是突变的，即所有故障电流往故障点流入，电流突变增大，电压降低。如果在闭环形智能配电网外发生故障整个闭环形智能配电网系统流进流出的负荷是相等的。 If a fault occurs in the closed-loop intelligent distribution network, the large difference protection of the bus differential protection device connected to the main node converter station will sense the unbalanced current, and it will change suddenly, that is, all the fault current will flow into the fault point, and the current will increase suddenly. The voltage drops. If a fault occurs outside the closed-loop intelligent distribution network, the load flowing in and out of the entire closed-loop intelligent distribution network system is equal.
主节点换流站连接的母差保护装置中有对应各子节点换流站的小差保护，同样感应到不平衡电流，并且是突变的（电流突变增大，电压降低），由此可以计算和比较出发生故障的直流母线子节点。如图2所示，直流母线1故障在主站母差保护装置计算出换流站1节点有差流等。 The bus differential protection device connected to the main node converter station has a small difference protection corresponding to each sub-node converter station, which also senses the unbalanced current, and it is sudden (the current suddenly increases and the voltage decreases), so it can be calculated and compare the faulty DC bus child nodes. As shown in Fig. 2, when the DC bus 1 is faulty, the bus differential protection device of the main station calculates that there is a differential flow at node 1 of the converter station.
主节点换流站连接的母差保护装置等待对应各子节点换流站的小差保护计算完毕后，将跳闸命令传达发生故障的子节点，进行跳闸将故障隔离。 The bus differential protection device connected to the main node converter station waits for the calculation of the small difference protection of the corresponding sub-node converter stations to be completed, and then transmits the trip command to the sub-node where the fault occurs, and performs tripping to isolate the fault.
实施本发明，具有如下有益效果： Implement the present invention, have following beneficial effect:
第一，本发明的柔性直流闭环形智能配电网母差保护系统及方法，可以解决目前在柔性直流输电中采用点对点的直流功率转送薄弱的问题。 First, the flexible DC closed-loop smart distribution network bus differential protection system and method of the present invention can solve the problem of weak point-to-point DC power transfer currently used in flexible DC transmission.
第二，本发明的柔性直流闭环形智能配电网母差保护系统及方法，可以解决目前交流供点电压质量差问题。具体的，本发明采用柔性直流的闭环形智能配电网系统至少有1个交流系统整流站充当调压站，作用主要是控制直流电压，起到平衡系统直流电压功能，提高电压质量。 Second, the bus differential protection system and method of the flexible DC closed-loop intelligent distribution network of the present invention can solve the current problem of poor voltage quality at AC supply points. Specifically, the present invention adopts a flexible DC closed-loop intelligent distribution network system with at least one AC system rectifier station acting as a voltage regulating station, whose main function is to control the DC voltage, balance the DC voltage of the system, and improve the voltage quality.
第三，本发明的柔性直流闭环形智能配电网母差保护系统及方法，可以解决输电通道走廊紧张局面的技术问题。具体的，本发明采用柔性直流的闭环形智能配电网系统，主要用于比较集中的城市，在直流输电线路采用直流电缆输电，只需要两条输电通道，节约了一条输电通道（如有三条输电线路就可以减少3条输电通道），另外还不受输电走廊的制约，便于扩容。另外，在本发明提供的基于柔性直流的闭环形智能配电网系统的直流输电线路两端不需要安装任何整流站和逆变站，节约成本。 Thirdly, the bus differential protection system and method of the flexible DC closed-loop intelligent distribution network of the present invention can solve the technical problem of the tense situation in the corridor of the transmission channel. Specifically, the present invention adopts a flexible DC closed-loop intelligent distribution network system, which is mainly used in relatively concentrated cities. DC cables are used for power transmission in DC transmission lines, and only two transmission channels are needed, saving one transmission channel (if there are three The transmission line can reduce 3 transmission channels), and it is not restricted by the transmission corridor, which is convenient for expansion. In addition, there is no need to install any rectifier station and inverter station at both ends of the DC transmission line of the flexible DC-based closed-loop intelligent distribution network system provided by the present invention, which saves costs.
第四，本发明的柔性直流闭环形智能配电网母差保护系统及方法，其将该柔性直流闭环形智能配电网中的一条直流母线所在的区域作为主节点换流站，其余作为子节点换流站，在主节点换流站上安装有母差保护装置，根据采集到的主节点换流站和子节点换流站上的电流和电压进行故障判断，可以有效而快捷的进行故障排除。 Fourth, the flexible DC closed-loop intelligent distribution network bus differential protection system and method of the present invention, which uses the area where one DC bus in the flexible DC closed-loop intelligent distribution network is located as the main node converter station, and the rest as sub-node converter stations. In the node converter station, a bus differential protection device is installed on the master node converter station, and the fault judgment can be carried out according to the collected current and voltage of the master node converter station and the sub-node converter station, which can effectively and quickly carry out troubleshooting .
以上内容是结合具体的优选实施方式对本发明所作的进一步详细说明，不能认定本发明的具体实施只局限于这些说明。对于本发明所属技术领域的普通技术人员来说，在不脱离本发明构思的前提下，还可以做出若干简单推演或替换，都应当视为属于本发明的保护范围。 The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it cannot be assumed that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field of the present invention, without departing from the concept of the present invention, some simple deduction or replacement can be made, which should be regarded as belonging to the protection scope of the present invention.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3188333A1 (en) * | 2015-12-30 | 2017-07-05 | Openhydro IP Limited | Array of electrical generator units and shedding of inter-unit transmission cables in response to fault |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9762047B2 (en) | 2015-06-16 | 2017-09-12 | Abb Technology Ltd. | Technologies for zonal fault protection of DC distribution systems |
| CN105207265B (en) * | 2015-10-23 | 2017-10-20 | 国网福建省电力有限公司 | The method that power distribution network closed loop and photovoltaic concentrate access is realized using flexible DC power transmission |
| CN110474302A (en) * | 2018-05-11 | 2019-11-19 | 南京南瑞继保电气有限公司 | A kind of mesolow DC distribution net bus protection relay system and method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102157929A (en) * | 2011-04-13 | 2011-08-17 | 国网电力科学研究院 | Main wiring method of multi-terminal ultra high voltage direct current transmission system |
| CN202068184U (en) * | 2010-12-09 | 2011-12-07 | 国家电网公司 | Cascade converter station and cascade multi-terminal HVDC system |
| CN102545200A (en) * | 2011-12-13 | 2012-07-04 | 河海大学 | Multi-port direct-current distribution network system based on voltage source converter |
| CN102751720A (en) * | 2012-04-11 | 2012-10-24 | 中国电力科学研究院 | Flexible high-voltage direct-current (HVDC) load flow computational model and computational method thereof |
| CN202917958U (en) * | 2012-10-31 | 2013-05-01 | 深圳供电局有限公司 | Bus differential protection system of flexible direct-current closed-loop intelligent power distribution network |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012044369A1 (en) * | 2010-09-30 | 2012-04-05 | Abb Research Ltd. | Coordinated control of multi-terminal hvdc systems |
-
2012
- 2012-10-31 CN CN201210425664.3A patent/CN103001191B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202068184U (en) * | 2010-12-09 | 2011-12-07 | 国家电网公司 | Cascade converter station and cascade multi-terminal HVDC system |
| CN102157929A (en) * | 2011-04-13 | 2011-08-17 | 国网电力科学研究院 | Main wiring method of multi-terminal ultra high voltage direct current transmission system |
| CN102545200A (en) * | 2011-12-13 | 2012-07-04 | 河海大学 | Multi-port direct-current distribution network system based on voltage source converter |
| CN102751720A (en) * | 2012-04-11 | 2012-10-24 | 中国电力科学研究院 | Flexible high-voltage direct-current (HVDC) load flow computational model and computational method thereof |
| CN202917958U (en) * | 2012-10-31 | 2013-05-01 | 深圳供电局有限公司 | Bus differential protection system of flexible direct-current closed-loop intelligent power distribution network |
Non-Patent Citations (4)
| Title |
|---|
| 多端柔性直流输电控制系统的研究;吴俊宏;《中国优秀硕士学位论文全文数据库》;20101015;第11-12页，第35页 * |
| 多端高压直流输电系统保护动作策略;王俊生等;《电力系统自动化》;20120525;第36卷(第10期);第101-106页 * |
| 环网式三端直流输电系统及直流断路器应用的分析与仿真;方进等;《电网技术》;20120630;第36卷(第6期);第244-247页 * |
| 高压直流输电技术现状及发展前景;梁旭明等;《电网技术》;20120430;第36卷(第4期);第1-7页 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3188333A1 (en) * | 2015-12-30 | 2017-07-05 | Openhydro IP Limited | Array of electrical generator units and shedding of inter-unit transmission cables in response to fault |
| WO2017114697A3 (en) * | 2015-12-30 | 2017-09-14 | Openhydro Ip Limited | Array of electrical generator units and shedding of inter-unit transmission cables in response to fault |
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