CN113839414A - 一种微电网接入电网的继电保护方法 - Google Patents

一种微电网接入电网的继电保护方法 Download PDF

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CN113839414A
CN113839414A CN202110870894.XA CN202110870894A CN113839414A CN 113839414 A CN113839414 A CN 113839414A CN 202110870894 A CN202110870894 A CN 202110870894A CN 113839414 A CN113839414 A CN 113839414A
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protection
relay
distribution network
voltage
grid
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李振伟
王晶
赵天翊
赵树军
单保涛
陶陈彬
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Xiongan New Area Power Supply Company State Grid Hebei Electric Power Co
State Grid Corp of China SGCC
State Grid Hebei Electric Power Co Ltd
Handan Power Supply Co of State Grid Hebei Electric Power Co Ltd
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Xiongan New Area Power Supply Company State Grid Hebei Electric Power Co
State Grid Corp of China SGCC
State Grid Hebei Electric Power Co Ltd
Handan Power Supply Co of State Grid Hebei Electric Power Co Ltd
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Priority to CN202110870894.XA priority Critical patent/CN113839414A/zh
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    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/381Dispersed generators
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02HEMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00Emergency 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
    • H02H7/26Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J13/00Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
    • H02J13/00006Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
    • H02J13/00016Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using a wired telecommunication network or a data transmission bus
    • H02J13/00017Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using a wired telecommunication network or a data transmission bus using optical fiber
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00Circuit arrangements for ac mains or ac distribution networks
    • H02J3/04Circuit arrangements for ac mains or ac distribution networks for connecting networks of the same frequency but supplied from different sources
    • H02J3/06Controlling transfer of power between connected networks; Controlling sharing of load between connected networks
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/388Islanding, i.e. disconnection of local power supply from the network
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2203/00Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
    • H02J2203/10Power transmission or distribution systems management focussing at grid-level, e.g. load flow analysis, node profile computation, meshed network optimisation, active network management or spinning reserve management
    • 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
    • Y02BCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B90/00Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02B90/20Smart grids as enabling technology in buildings sector
    • 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
    • Y02E40/00Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/70Smart grids as climate change mitigation technology in the energy generation sector
    • 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
    • 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
    • Y04INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04SSYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00Systems supporting electrical power generation, transmission or distribution
    • Y04S10/12Monitoring or controlling equipment for energy generation units, e.g. distributed energy generation [DER] or load-side generation
    • 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
    • Y04INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04SSYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00Systems supporting electrical power generation, transmission or distribution
    • Y04S10/16Electric power substations
    • 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
    • Y04INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04SSYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00Systems supporting electrical power generation, transmission or distribution
    • Y04S10/20Systems supporting electrical power generation, transmission or distribution using protection elements, arrangements or systems
    • 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
    • Y04INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04SSYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S40/00Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them
    • Y04S40/12Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them characterised by data transport means between the monitoring, controlling or managing units and monitored, controlled or operated electrical equipment
    • Y04S40/124Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them characterised by data transport means between the monitoring, controlling or managing units and monitored, controlled or operated electrical equipment using wired telecommunication networks or data transmission busses

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  • Emergency Protection Circuit Devices (AREA)

Abstract

本发明公开了一种微电网接入电网的继电保护方法,包括基于区域差动的配电网继电保护方法和基于正反方向阻抗继电器的低压配电网继电保护配置方法。本发明提出了微电网接入对配电网一次设备的要求,实现了配电网故障识别、定位、故障隔离及保护的功能,同时配合微电网***,进行微电网孤岛运行方式的识别及相关的处理措施,以确保分布式电源在多电源、多电源种类、复杂供电模式及运行方式下微机保护的可靠性及有效性为目标;解决分布式电源接入电网产生的随机性及波动性,以及对配电网继电保护和低压配电保护的影响。

Description

一种微电网接入电网的继电保护方法
技术领域
本发明涉及一种微电网接入电网的继电保护方法,属于电网继电技术领域。
背景技术
微电网是指由分布式发电、储能装置、能量变换装置、相关负荷等组成的发电***,是能够实现自我控制、保护和管理的自治***,拥有并网和离网两种运行模式,微电网接入给电力***保护带来新的问题。微电网随着DG数量和渗透率的逐渐增加可能改变其内部潮流的方向,从而给整个电网带来影响。并网运行时其潮流存在双向流动,其双向流动的特点改变了常规配电网单向流动的特征,同时微电网接入要求采用电力电子技术实现“柔性”接入,其电源特征与常规的“旋转”发电机发电接入不同,微电网的接入对配电网继电保护和低压配电保护带来一定影响。
对配电网继电保护的影响:常规10kV配电网分为的单向辐射型网络或“手拉手”环网型开环运行方式。传统辐射状单端电源过流保护无方向元件,大量的DG接入后,配电***变成多电源网络,正常运行时配电网中的潮流分布及故障时短路电流的大小、流向和分布均会发生变化,传统保护间的配合关系被打破,保护的动作行为和性能将无法满足新的要求。当接入DG后为两侧电源,类似于在配电网接入一个常规的发电机,因此也自然应如同传统两侧电网一样,对于继电保护的影响仍是相邻线路保护误动问题,重合闸不能正常熄弧重合不成功问题。
对低压配电保护的影响:低压配电***电压等级0.4kV(380/220V),保护配置通常采用带继电保护的低压断路器(又称万能断路器)及采用熔断器保护、热继电器保护等。并网运行短路电流远远大于离网运行时短路电流,并网运行时短路电流主要是由配电网***电源提供。并网运行时低压配电网故障时,***电源及分布式电源共同提供故障电流,主要是由配电网电源提供,故障电流比没有DG接入时大;离网(孤岛)运行时低压配电网故障时DG提供故障电流,故障电流小。同时离网(孤岛)运行故障时由于逆变器的限流允许的最大输出电流为1.5In;传统的带继电保护的低压断路器脱扣时间接近1h(In<63A),无法实现快速隔离故障的要求。
发明内容
本发明所要解决的技术问题是提供一种微电网接入电网的继电保护方法,解决分布式电源接入电网产生的随机性及波动性,以及对配电网继电保护和低压配电保护的影响。为解决上述问题,本发明所采取的技术方案是:
一种微电网接入电网的继电保护方法,包括基于区域差动的配电网继电保护方法和基于正反方向阻抗继电器的低压配电网继电保护配置方法。
作为本发明的进一步改进,所述基于区域差动的配电网继电保护方法,采用高压***中成熟差动保护的方案,配置全线速动差动保护做区域差动主保护,配置简单过流作后备保护。
作为本发明的进一步改进,所述区域差动主保护配置如下:对于10kV电压等级配电网,按照差动保护对象划分为三个保护区域,包括线路差动保护区域、母线差动保护区域和配电变压器保护区域;对于配电变压器保护区域的差流计算考虑Δ/Y转角的影响,对于其他保护区域在假设电流的正方向为母线流向线路的前提下,差流为各侧电流的矢量和。
作为本发明的进一步改进,所述区域差动主保护采用启动判据与比率制动判据组成与门出口;
启动判据为:
Figure BDA0003188853080000021
比率制判据为:
Id>kIr (2)
式中:Id为差动电流,
Figure BDA0003188853080000022
Iop0为启动判据的整定值,Ir为制动电流,
Figure BDA0003188853080000023
k为比率制动系数,
Figure BDA0003188853080000024
为被保护对象各侧电流。
作为本发明的进一步改进,断路器配置智能采集单元,通过PTN光纤通讯网,采用IEC61850标准中采样值及面向通用对象的变电站事件报文机制完成信息交互;所述区域差动主保护与智能采集单元通过光纤环网利用PTN技术传输数据,采用基于IEEE1588对时的同步机制,实现100ns级同步精度;
所述区域差动主保护基于的微电网三层体系结构,分别是就地控制层的智能采集单元、集中控制层的区域差动保护和配网调度层的配网调度***;集中控制层的区域差动保护采取双重化冗余配置;
区域差动主保护通过采集配电网***各个节点的电流和状态信息,利用网络化的差动保护,实现故障自动定位和隔离。
作为本发明的进一步改进,配电网***配备带时限过流或方向过流保护作为后备保护,具备配置如下:
就地智能采集单元配置后备保护功能,线路就地采集单元配置距离保护作为线路及母线的后备保护,变压器就地采集单元配置过流保护作为变压器的后备保护;
配电升压变压器的高压侧配置定时限方向过流保护作为变压器内部故障的后备保护,方向指向电源点,用以切除0.4kV母线故障,作为子微网内部故障的后备保护;
配电降压变压器配置定时限过流保护,按躲过最大负荷电流整定。
作为本发明的进一步改进,所述基于正反方向阻抗继电器的低压配电网继电保护配置方法如下:对于含有微电网的低压配电网,在有DG的馈线单元配置正、反方向的两种方向阻抗继电器构成距离保护,正方向阻抗继电器无延时出口,用于保护出线故障,反方向阻抗继电器延时0.5S出口,用于保护低压母线故障;无DG的馈线单元,配置正方向阻抗继电器构成距离保护,正方向阻抗继电器无延时出口,用于保护出线故障。
作为本发明的进一步改进,所述阻抗继电器采用过流启动,记忆正序电压极化,由于0.4kV电压等级阻抗角较小,阻抗动作特性采用偏移阻抗特性。
作为本发明的进一步改进,所述正方向阻抗继电器的定值按躲开最大负荷整定,当本线路相间或接地短路时该继电器动作,延时0S,快速出口跳开本线路的断路器;
所述反方向阻抗继电器的定值按躲开变压器高压侧母线短路或按躲开高压侧出线电流速断保护末端短路整定,其保护范围至变压器内部或至高压线路或低压线路;当低压母线相间或接地短路时含有DG馈线单元的反方向继电器动作,延时0.5S跳开本线路的DL,切断本DG向外供电;当其他低压线路或变压器或高压线路的一部分短路时,馈线单元的反方向阻抗继电器虽动作,但由于延时0.5S,出口不动作,不跳开本线路的断路器,待故障切除后,该继电器自动返回。
作为本发明的进一步改进,所述阻抗继电器保护的动作流程如下:电流元件启动后,正方向阻抗元件动作,判为本分支故障,跳开本分支故障;反方向阻抗元件动作,经延时元件动作后,跳开本分支线路断路器。
采用上述技术方案所产生的有益效果在于:
本发明提出了微电网接入对配电网一次设备的要求,提出了基于区域差动保护解决配电网保护的解决方案和基于正反方向阻抗解决低压配电保护的解决方案,实现了配电网故障识别、定位、故障隔离及保护的功能,同时配合微电网***,进行微电网孤岛运行方式的识别及相关的处理措施,以确保分布式电源在多电源、多电源种类、复杂供电模式及运行方式下微机保护的可靠性及有效性为目标。
附图说明
为了更清楚地说明本发明实施例中的技术方案,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的前提下,还可以根据这些附图获得其他的附图。
图1是微电网***负荷电流流向示意图;
图2是微电网***及含有多个子微电网的保护配置示意图;
图3是配电升压变压器保护示意图;
图4是配电降压变压器保护示意图;
图5是PPC的离网保护逻辑图。
具体实施方式
下面将结合本申请实施例中的附图,对本申请实施例中的技术方案进行清楚、完整地描述,显然,所描述的实施例仅仅是本申请一部分实施例,而不是全部的实施例。以下对至少一个示例性实施例的描述实际上仅仅是说明性的,决不作为对本申请及其应用或使用的任何限制。基于本申请中的实施例,本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例,都属于本申请保护的范围。
需要注意的是,这里所使用的术语仅是为了描述具体实施方式,而非意图限制根据本申请的示例性实施方式。如在这里所使用的,除非上下文另外明确指出,否则单数形式也意图包括复数形式,此外,还应当理解的是,当在本说明书中使用术语“包含”和/或“包括”时,其指明存在特征、步骤、操作、器件、组件和/或它们的组合。
除非另外具体说明,否则在这些实施例中阐述的部件和步骤的相对布置、数字表达式和数值不限制本申请的范围。对于相关领域普通技术人员已知的技术、方法和设备可能不作详细讨论,但在适当情况下,所述技术、方法和设备应当被视为授权说明书的一部分。在这里示出和讨论的所有示例中,任何具体值应被解释为仅仅是示例性的,而不是作为限制。
一种微电网接入电网的继电保护方法,包括基于区域差动的配电网继电保护方法和基于正反方向阻抗继电器的低压配电网继电保护配置方法。
低压配电***电压等级0.4kV(380/220V),保护配置通常采用带继电保护的低压断路器(又称万能断路器)及采用熔断器保护、热继电器保护等。
如图1是微电网***负荷电流流向图,
Figure BDA0003188853080000051
是配电网***电势,
Figure BDA0003188853080000052
是分布式电源电势,PCC是公共连接点,Zf是微电网负荷,
Figure BDA0003188853080000053
为负荷电流。正常并网运行时,配电网***电源
Figure BDA0003188853080000054
及分布式电源
Figure BDA0003188853080000055
共同提供负荷电流,离网运行分布式电源
Figure BDA0003188853080000056
提供负荷电流。
根据对称分量法,由不同故障的复合序网分析可知,三相短路故障电流最大;两相短路次之,为三相短路的0.87倍;单相接地故障电流最小,为三相短路的0.55倍或0.75倍。
由于DG的等效参数难以得到,下面采用短路容量法计算并网运行、离网运行时的短路电流。并网运行,配电网***电源
Figure BDA0003188853080000057
及分布式电源
Figure BDA0003188853080000058
并联,***电源
Figure BDA0003188853080000059
的配电变压器的短路容量为
Figure BDA00031888530800000510
U1k%为短路阻抗(短路电压),S1N为配电变压器容量,***电源提供的短路电流
Figure BDA00031888530800000511
按照逆变器的过电流保护不大于额定电流的1.5倍,分布式电源
Figure BDA00031888530800000512
的短路容量为S2k=1.5S2N,S2N
Figure BDA00031888530800000513
逆变器容量,分布式电源
Figure BDA00031888530800000514
提供的短路电流
Figure BDA00031888530800000515
并网运行最大短路电流Ik=I1k+I2k;离网运行由分布式电源
Figure BDA00031888530800000516
单独供电,最大短路电流Ik=I2k
并网运行短路电流远远大于离网运行时短路电流,并网运行时短路电流主要是由配电网***电源提供。并网运行时低压配电网故障时,***电源及分布式电源共同提供故障电流,主要是由配电网电源提供,故障电流比没有DG接入时大;离网(孤岛)运行时低压配电网故障时DG提供故障电流,故障电流小。同时离网(孤岛)运行故障时由于逆变器的限流允许的最大输出电流为1.5In;传统的带继电保护的低压断路器脱扣时间接近1h(In<63A),无法实现快速隔离故障的要求。
本实施例具体的,所述基于区域差动的配电网继电保护方法,采用高压***中成熟差动保护的方案,配置全线速动差动保护做区域差动主保护,配置简单过流作后备保护。
本实施例具体的,所述区域差动主保护配置如下:对于10kV电压等级配电网,按照差动保护对象划分为三个保护区域,包括线路差动保护区域、母线差动保护区域和配电变压器保护区域;对于配电变压器保护区域的差流计算考虑Δ/Y转角的影响,对于其他保护区域在假设电流的正方向为母线流向线路的前提下,差流为各侧电流的矢量和。
本实施例具体的,所述区域差动主保护采用启动判据与比率制动判据组成与门出口;启动判据为:
Figure BDA0003188853080000061
比率制判据为:
Id>kIr (2)
式中:Id为差动电流,
Figure BDA0003188853080000062
Iop0为启动判据的整定值,Ir为制动电流,
Figure BDA0003188853080000063
k为比率制动系数,
Figure BDA0003188853080000064
为被保护对象各侧电流。
本实施例具体的,断路器配置智能采集单元,通过PTN光纤通讯网,采用IEC61850标准中采样值及面向通用对象的变电站事件报文机制完成信息交互;所述区域差动主保护与智能采集单元通过光纤环网利用PTN技术传输数据,采用基于IEEE1588对时的同步机制,实现100ns级同步精度;
如图2是配电网***及含有多个子微电网的保护配置示意图,所述区域差动主保护基于的微电网三层体系结构,分别是就地控制层的智能采集单元、集中控制层的区域差动保护和配网调度层的配网调度***;集中控制层的区域差动保护采取双重化冗余配置;区域差动主保护通过采集配电网***各个节点的电流和状态信息,利用网络化的差动保护,实现故障自动定位和隔离。
本实施例具体的,配电网***配备带时限过流或方向过流保护作为后备保护,具备配置如下:
就地智能采集单元配置后备保护功能,线路就地采集单元配置距离保护作为线路及母线的后备保护,变压器就地采集单元配置过流保护作为变压器的后备保护;
配电升压变压器的高压侧配置定时限方向过流保护,如图3所示,作为变压器内部故障的后备保护,方向指向电源点,用以切除0.4kV母线故障,作为子微网内部故障的后备保护;
配电降压变压器配置定时限过流保护,如图4所示,按躲过最大负荷电流整定。
对配电网一次设备及继电保护的要求由于微电网的接入,传统的配电一次设备无法满足快速故障隔离要求,因此需要配电网的一次设备配置为:1)10kv以上配电网宜全部配置断路器;2)0.4kv低压配电网宜配置支持外部遥控功能的微型断路器;3)微电网接入应保证原有0.4kV低压配电网接地方式不变,孤岛运行时,应考虑DG的接地。
本实施例具体的,所述基于正反方向阻抗继电器的低压配电网继电保护配置方法如下:对于含有微电网的低压配电网,在有DG的馈线单元配置正、反方向的两种方向阻抗继电器构成距离保护,正方向阻抗继电器无延时出口,用于保护出线故障,反方向阻抗继电器延时0.5S出口,用于保护低压母线故障;无DG的馈线单元,配置正方向阻抗继电器构成距离保护,正方向阻抗继电器无延时出口,用于保护出线故障。
本实施例具体的,所述阻抗继电器采用过流启动,记忆正序电压极化,由于0.4kV电压等级阻抗角较小,阻抗动作特性采用偏移阻抗特性。
本实施例具体的,所述正方向阻抗继电器的定值按躲开最大负荷整定,当本线路相间或接地短路时该继电器动作,延时0S,快速出口跳开本线路的断路器;
所述反方向阻抗继电器的定值按躲开变压器高压侧母线短路或按躲开高压侧出线电流速断保护末端短路整定,其保护范围至变压器内部或至高压线路或低压线路;当低压母线相间或接地短路时含有DG馈线单元的反方向继电器动作,延时0.5S跳开本线路的DL,切断本DG向外供电;当其他低压线路或变压器或高压线路的一部分短路时,馈线单元的反方向阻抗继电器虽动作,但由于延时0.5S,出口不动作,不跳开本线路的断路器,待故障切除后,该继电器自动返回。
如图5为对微电网离网运行时保护动作及故障分析;DG出口dl点故障,L2的正方向阻抗继电器满足动作条件;Ll、L3正方向阻抗继电器不动作,反方向阻抗继电器动作;L4、L5由于电流接近于零,正、反方向继电器均不动作,L2的保护切除故障后,Ll、L3反方向阻抗继电器返回。
母线d2点故障,L1、L2、L3正方向阻抗继电器不动作,反方向阻抗继电器动作;L4、L5正、反方向阻抗继电器均不动作。Ll、L2、L3反方向阻抗继电器经延时跳闸。d3点故障,L4正方向阻抗继电器动作;L1、L2、L3反方向继电器均动作;待故障切除后,L1、L2、L3反方向阻抗继电器返回。L5正、反方向阻抗继电器均不动作,L4正方向阻抗继电器动作跳闸,切除故障。
本实施例具体的,所述阻抗继电器保护的动作流程如下:电流元件启动后,正方向阻抗元件动作,判为本分支故障,跳开本分支故障;反方向阻抗元件动作,经延时元件动作后,跳开本分支线路断路器。
最后应说明的是:以上实施例仅用以说明本发明的技术方案,而非对其限制;尽管参照前述实施例对本发明进行了详细的说明,本领域的普通技术人员应当理解:其依然可以对前述实施例所记载的技术方案进行修改,或者对其中部分技术特征进行等同替换;作为本领域技术人员对本发明的多个技术方案进行组合是显而易见的。而这些修改或者替换,并不使相应技术方案的本质脱离本发明实施例技术方案的精神和范围。

Claims (10)

1.一种微电网接入电网的继电保护方法,其特征在于:包括基于区域差动的配电网继电保护方法和基于正反方向阻抗继电器的低压配电网继电保护配置方法。
2.根据权利要求1所述的一种微电网接入电网的继电保护方法,其特征在于:所述基于区域差动的配电网继电保护方法,采用高压***中成熟差动保护的方案,配置全线速动差动保护做区域差动主保护,配置简单过流作后备保护。
3.根据权利要求2所述的一种微电网接入电网的继电保护方法,其特征在于,所述区域差动主保护配置如下:对于10kV电压等级配电网,按照差动保护对象划分为三个保护区域,包括线路差动保护区域、母线差动保护区域和配电变压器保护区域;对于配电变压器保护区域的差流计算考虑△/Y转角的影响,对于其他保护区域在假设电流的正方向为母线流向线路的前提下,差流为各侧电流的矢量和。
4.根据权利要求3所述的一种微电网接入电网的继电保护方法,其特征在于,所述区域差动主保护采用启动判据与比率制动判据组成与门出口;
启动判据为:
Figure FDA0003188853070000011
比率制判据为:
Id>kIr (2)
式中:Id为差动电流,
Figure FDA0003188853070000012
Iop0为启动判据的整定值,Ir为制动电流,
Figure FDA0003188853070000013
k为比率制动系数,
Figure FDA0003188853070000014
为被保护对象各侧电流。
5.根据权利要求4所述的一种微电网接入电网的继电保护方法,其特征在于,断路器配置智能采集单元,通过PTN光纤通讯网,采用IEC61850标准中采样值及面向通用对象的变电站事件报文机制完成信息交互;所述区域差动主保护与智能采集单元通过光纤环网利用PTN技术传输数据,采用基于IEEE1588对时的同步机制,实现100ns级同步精度;
所述区域差动主保护基于的微电网三层体系结构,分别是就地控制层的智能采集单元、集中控制层的区域差动保护和配网调度层的配网调度***;集中控制层的区域差动保护采取双重化冗余配置;
区域差动主保护通过采集配电网***各个节点的电流和状态信息,利用网络化的差动保护,实现故障自动定位和隔离。
6.根据权利要求5所述的一种微电网接入电网的继电保护方法,其特征在于,配电网***配备带时限过流或方向过流保护作为后备保护,具备配置如下:
就地智能采集单元配置后备保护功能,线路就地采集单元配置距离保护作为线路及母线的后备保护,变压器就地采集单元配置过流保护作为变压器的后备保护;
配电升压变压器的高压侧配置定时限方向过流保护作为变压器内部故障的后备保护,方向指向电源点,用以切除0.4kV母线故障,作为子微网内部故障的后备保护;
配电降压变压器配置定时限过流保护,按躲过最大负荷电流整定。
7.根据权利要求1所述的一种微电网接入电网的继电保护方法,其特征在于,所述基于正反方向阻抗继电器的低压配电网继电保护配置方法如下:对于含有微电网的低压配电网,在有DG的馈线单元配置正、反方向的两种方向阻抗继电器构成距离保护,正方向阻抗继电器无延时出口,用于保护出线故障,反方向阻抗继电器延时0.5S出口,用于保护低压母线故障;无DG的馈线单元,配置正方向阻抗继电器构成距离保护,正方向阻抗继电器无延时出口,用于保护出线故障。
8.根据权利要求7所述的一种微电网接入电网的继电保护方法,其特征在于,所述阻抗继电器采用过流启动,记忆正序电压极化,由于0.4kV电压等级阻抗角较小,阻抗动作特性采用偏移阻抗特性。
9.根据权利要求8所述的一种微电网接入电网的继电保护方法,其特征在于,所述正方向阻抗继电器的定值按躲开最大负荷整定,当本线路相间或接地短路时该继电器动作,延时0S,快速出口跳开本线路的断路器;
所述反方向阻抗继电器的定值按躲开变压器高压侧母线短路或按躲开高压侧出线电流速断保护末端短路整定,其保护范围至变压器内部或至高压线路或低压线路;当低压母线相间或接地短路时含有DG馈线单元的反方向继电器动作,延时0.5S跳开本线路的DL,切断本DG向外供电;当其他低压线路或变压器或高压线路的一部分短路时,馈线单元的反方向阻抗继电器虽动作,但由于延时0.5S,出口不动作,不跳开本线路的断路器,待故障切除后,该继电器自动返回。
10.根据权利要求9所述的一种微电网接入电网的继电保护方法,其特征在于,所述阻抗继电器保护的动作流程如下:电流元件启动后,正方向阻抗元件动作,判为本分支故障,跳开本分支故障;反方向阻抗元件动作,经延时元件动作后,跳开本分支线路断路器。
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CN115313365A (zh) * 2022-08-04 2022-11-08 国网湖北省电力有限公司电力科学研究院 一种配电网后备保护方法及装置
CN115313365B (zh) * 2022-08-04 2024-04-26 国网湖北省电力有限公司电力科学研究院 一种配电网后备保护方法及装置
CN116826674A (zh) * 2023-06-19 2023-09-29 国网湖北省电力有限公司电力科学研究院 一种适配控制模式切换的光储充群直流微电网极间故障保护方法
CN116826674B (zh) * 2023-06-19 2024-06-11 国网湖北省电力有限公司电力科学研究院 一种适配控制模式切换的光储充群直流微电网极间故障保护方法

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