变电站系统过电压防护技术--中英文翻译.doc

英文文献substation system over-voltage protection technologysecond substation equipment over-voltage protection on electronic information system for the protection of core equipment for the construction of a protected both pressure and other potential system, and through all levels of over-voltage surge protectors of the current step by step into the land of china, substation secondary safety equipment and reliable operation.1 second over-voltage substation protection in recent years, the substation communications, communications systems, protection systems, background management module frequent over-voltage damage, the main reason for this is weak and its related systems products over-voltage protection level is weak, or no guard against over-voltage technical measures, the consequences for the safe operation of power grids bring about a greater negative impact. with integrated automation systems and automation systems such as communication systems in the substation weak secondary by the wider use of such electronic systems (equipment) components of the integrated more and more, the growing volume of information storage, speed and accuracy of the increased and operates only a few volts, current information only microamp level, thus extremely sensitive to outside interference, especially the lightning and electromagnetic pulse, such as over-voltage tolerance is low. when thunder and lightning, such as over-voltage and accompanied by the electromagnetic fields reach a certain threshold, ranging from system failure caused, resulted in heavy equipment or permanent damage to its components. despite the thunder and lightning viewpoint of electronic systems (equipment) is unlikely, but lightning strike near the land, buildings, communication and air supply line directly leiyun discharge form, or because of electrostatic induction and the impact of electromagnetic induction formation of over-voltage, there might be connected to the power lines, signal lines or grounding system, through various interfaces to transfer, coupling, radiation and other forms of invasive electronic system (equipment) and lead to serious disturbances or incidents. therefore, strengthening and improving the electronic system (equipment) protection, to minimize the impact of interference by lightning and other damage caused direct losses and indirect losses, has become the urgent need to solve the problem.2 over-voltage protection design iec (international electrotechnical commission) tc/81 mine technical committee will be divided into internal and external mine mine in two parts, the external mine is lightning rod (or with lightning, lightning network), yin xiaxian and grounding system, objects to be protected from direct lightning strikes, mine is to prevent internal lightning and other internal over-voltage damage caused by invasive equipment. a comprehensive mine and over-voltage protection systems must be integrated use of discharge (segregation), both pressure (and other potential), shielding (isolation), grounded, limit pressure (clamp) protection, and other technology, in accordance with the external mine and the principle of internal mine, in accordance with the targets of protective features, flexible application to take concrete measures, constitute a complete protection system. over-voltage substation in the form are: lightning over-voltage, the resonant frequency over-voltage and over-voltage, over-voltage operation, these over-voltage transmission or electromagnetic induction to the way the lines and equipment on a dangerous over-voltage, in particular, lightning over-voltage, lightning substation, in the low-voltage power supply system and weak system to produce a strong over-voltage sensor, while the substation to potential rise (for example: the substation grounding resistance to 1 q, lightning current 10 ka, while the potential for 10 kv), due to the increased potential of the counter lines and equipment damaged lines and equipment and the events have occurred, therefore, despite the substation outside the mine system (lightning rod. yin xiaxian and grounding devices) in line with national standards and the requirements of buban, and the integrated automation and communications automation systems, such as weak secondary have been taken, such as shielding, grounding, isolation, filtering, and other measures, but it can not completely avoid over-voltage powerful lightning and voltage of the system counter the disruption caused damage and, therefore, the second weak system substation and a mine-voltage must also take the appropriate protective measures, in accordance with the iec within the mine area emp, the devices power cord, signal lines, data lines, and the installation of lightning protection and internal over-voltage devices to prevent lightning sensors, channeling people along the lightning current, voltage counterattack, such as transient voltage surge too transient over-voltage caused by a fault and damaged electronic equipment. over-voltage surge protection in accordance with its connection mode is divided into two series and parallel, the use of over-voltage surge protection tandem with, there may exist because of signal transmission does not match the causes of transmission of the signal interference, in particular data communication interface in the series were over-voltage surge protection in place, will have the normal data communications. therefore, the data communications access i: i in the series were over-voltage surge protection in place, the transmission of data must be carried out conscientiously check if the data are not normal transmission, it may be due to the reasons do not match the transmission signal interference, should be replaced to match the over-voltage surge protection for. if the use of over-voltage surge protection for use of parallel, the situation is basically non-existent, but the connection mode of over-voltage surge protection for higher technical requirements.3 secondary system over-voltage substation protection 3.1 points over-voltage electricity system protection substation installed in the communications dispatch automation systems are used ac power or a dc power supply equipment for the rectification of its links are generally larger capacity filter capacitance, the transient over-voltage shock absorption of a certain extent, the station low-voltage transformer side go to feed between the screen using a shielded cable and equipment have a good grounding, the use of modern technology to analyze mine, we must increase the circuits segregation measures, because its grounding, protection and other electrical grounding all grounding devices using the same equipment, and equipment are in a lpzob, the relative strength of strong electromagnetic pulse, the station changed to prevent low-pressure side although there are lines intrusive wave arrester, but the residual pressure high, in the substation of lightning, through the line coupling and the potential rise caused by over-voltage counterattack still exist, and high-pressure side of the residual pressure as high as several thousand volts, it is necessary to these scheduling automation equipment for the power supply over-voltage circuit protection. lightning protection in accordance with the principle of regional division, substation equipment in the secondary power supply system over-voltage sensors lightning protection may be two (b, c level) for the protection of segregation. b-mine use is generally greater flow capacity of the mine installations, the lightning could be more casual liuxie people, to achieve the objective of current limit, over-voltage at the same time will reduce to a certain extent, c-mine use with lower residual pressure of the mine installations, you can loop in the remaining scattered lightning liuxie people, to limit the purpose of over-voltage, over-voltage equipment can be reduced to the level of tolerance. the main power supply system is inhibited lightning protection and operation of the power back to the road and over-voltage surge. according to the substation status of the substation of the second mine-sensing system and the operation and use of two over-voltage protection. as build more substations in the region more open, relatively strong electromagnetic strength, power lines and communication cables are very vulnerable to lightning attacks sensors, sensors along the over-voltage power lines and communication lines into one device, which will damage equipment, therefore, the exchange of first-class bus to install the power protection (b level) is to ensure the safety of the entire control room, and 80 percent of the over-voltage china, scattered to the earth, play a primary role in the protection, but are still in the exchange of feeder some of the b-level power supply voltage and mine the residual pressure increases on-line and must therefore be important in the exchange of feeder lines (dc charging screen, ups, etc.) c-level power protection, which would curb over-voltage electrical equipment to back-end to the level of tolerance.protective location: it is 1 ec1312 (lemp protection in the region of lightning protection principles. arrester installation should be in different locations at the junction of protected areas, this network, the first-class protection should be located in the bus exchange. in two on the bus with the installation of a b-class models of a three-phase power supply voltage surge protector. install location: ac bus (cabinet). 3.1.2 second-class protection measures to deal with for the more important feeder lines on the exchange of equipment, here for the dc charge screen, the installation of c-level three-phase power arrester. as dc charging screen is two-way exchange of electricity supply, so the screen in the dc charge with the installation of two models of c-level three-phase power supply over-voltage surge protector. installation location should choose the dc charge screen open exchange of air power commissioner office. 3.2 integrated automation system over-voltage protection protective position: computer-based integrated automation systems ability to bear a very low voltage, several hundred volts of over-voltage is enough to damage the equipment, so must the high side arrester the residual pressure (thousands of volts) to further curb to meet equipment insulation level of need, and because of the potential rise to power and the induction loop is also over-voltage line up on kv, to be used in the exchange of integrated automation system to the exchange on the c-level single-phase installation of a surge voltage protection. location should choose to install automated-ping in the composite air switch the ac power.3.3 did not ask off power supplies (ups) over-voltage protection protection here: because of the internal computer systems, hubs, monitoring equipment, electric energy billing systems and so on through the ups power supply protection, in order to protect the safety of these micro-electronics equipment, the ups power supply device in front of the installation of a c-surge voltage protection. optional models: the (ups for single-phase power input) c-class single-phase power surge or over-voltage protection (ups for the three-phase power input) of c-level three-phase power supply over-voltage surge protector. installation should choose the location of ups into the front line. 3.4 communication interface over-voltage protection communication interface over-voltage protection compared with the grid supply system, this over-voltage circuit on the degree of sensitivity is much higher, and these are over-voltage equipment in the circumstances it is very fragile. equipment insulation tolerance level is very low. with the equipment connected to a signal line, data lines, measurement and control lines, and these are basically in line lpzob region, but also through the lvzoa region, on the lines of sensors over-voltage relatively strong, according to the iec test, when the electromagnetic field strength increased to 0.07 gs, will have a micro-computer equipment malfunction, loss of data. and the safety of these circuits is directly related to a system of safety equipment, so important to be on the interface circuit over-voltage protection. 3.4.1 remote computer interface devices over-voltage protection protective position: as substation computer remote installations scattered distribution structure. from remote modules, intelligent telemetry module, intelligent remote control module, intelligent remote-module. the modules are installed in different automated-ping, through the rs232 interface between the modules or field bus communication. these interfaces are in the indoor circuit, equipment interface circuits shorter the distance, so there will be no more sensors to the over-voltage, but the automation equipment and other secondary equipment (measurement unit, computer, etc.) have electrical connections, when other secondary equipment sensors to a strong over-voltage sensors, will be counter to these automation equipment, communications interface, so that damage to equipment interface circuits, it is necessary in these devices rs232 interfaces on the installation of a surge voltage protection. installation location should choose the remote computer interface devices, communications lines. 3.4.2 electric energy billing system signals over-voltage protection a protective position: a multi-functional electronic power substation table, energy acquisition, the electronic power meter to bear a very low voltage levels. as meter and remote computer stations in the communications equipment used rs232 interfaces, the communication line is longer, and in lvzob region, near the substation or by direct lightning strike at the substation, proximity to the high voltage sensors, in order to prevent damage to equipment. e-meter in and around the rs232 port rs232 installation of the over-voltage surge protector. location should choose to install electronic power meter in and around the port, rs232. the location of protection: electronic power meter through the acquisition of information on the collectors modem (modem) from telephone lines to send data to a remote, since the introduction of telephone lines from the outside, the lines on the sensor to sensor lightning current relatively strong, easy to modem interface equipment damage, it is necessary in the telephone line modem interface, the installation of an interface over-voltage surge protector. location should choose to install telephone chuxian inside and outside phone lines-the-line people.3.4.3 distance communication interface over-voltage protection protective position: since the basic use of unmanned substation. on the first circuit protection, measurement, control, regulation of signal through the optical and data communications network or carrier to the distance (in tune, and stressed that the centralized control stations, etc.) to transmit data. if the carrier, the carrier and the computer automation of the signal devices connected relatively long lines, substations in the vicinity of a direct lightning strike or substations.should be a strong over-voltage sensors, to be near the computer automation devices to signal i: i-the installation of signal arrester, while in the area and extend to lpzob lpzoa area of communication lines (ddn, x.25) very easy lightning sensors on the over-voltage, must also be the installation of over-voltage surge protector. installation location should choose the remote device communication line interface department. secondary system over-voltage substation protection issues in recent years by a new task, the above is only related to the scene of the unit into the actual situation on the protection of the preliminary measures, it will be in continuing to draw on practical experience of running a summary analysis and continuous improvement, hope that the new substation in the future or the old substation automation of integrated, strengthen the secondary over-voltage protection system of planning and design, equipment and ensure the safe and stable operation of power grids.变电站系统过电压防护技术变电站的过电压保护是以电子信息系统为保护核心，为被保护设备构建一个均压等电位系统，并通过各级过电压浪涌保护器逐级把电流泄放入大地，使变电站设备安全和可靠地运行。1 变电站过电压防护近年来，变电站的通信、通信系统、继电保护系统、后台管理模块经常发生过电压损毁事件，究其原因主要是其相关系统和弱电产品过电压防护水平较弱，甚至根本没有过电压防范技术措施，其后果对电网的安全运行带来了较大负面影响。随着综合自动化系统和通信自动化系统等二次弱电系统在变电站的广泛应用，这类电子系统(设备)元器件的集成度愈来愈高，信息存储量愈来愈大，速度和精度不断提高，而工作电压只有几伏，信息电流仅为微安级，因而对外界干扰极其敏感，特别对雷电等电磁脉冲和过电压的耐受能力很低。当雷电等过电压和伴随的电磁场达到某一阀值时，轻则引起系统失灵，重则导致设备或其元器件永久性损坏。尽管雷电直击电子系统(设备)的可能性不大，但是雷击附近大地、建筑物、交流供电线路和空中雷云放电时直接形成的，或者由于静电感应及电磁感应形成的冲击过电压，都有可能通过与之相连的电力线路、信号线路或接地系统，通过各种接口，以传导、耦合、辐射等形式，侵入电子系统(设备)并酿成严重的干扰或事故。因此，加强和改进电子系统(设备)的防护，尽量减小其遭受雷电等冲击干扰损害造成的直接损失和间接损失，已成为当今亟待解决的问题。2 过电压保护设计iec(国际电工委员会)tc81技术委员会将防雷分为外部防雷和内部防雷两个部分，外部防雷是指避雷针(或避雷带、避雷网)、引下线和接地系统，是被保护物体免受直接雷击；内部防雷则是防止雷电和其他内部过电压侵入设备造成的毁坏。一个完善的防雷及过电压保护系统必须综合运用泄流(分流)、均压(等电位)、屏蔽(隔离)、接地、限压(箝位)保护等各项技术，按照外部防雷和内部防雷的原则，根据防护对象的特点，灵活应用，采取具体措施，构成一个完整的防护体系。变电站内的过电压形式主要有：雷电过电压、工频过电压及谐振过电压、操作过电压等，这些过电压以传导或电磁感应的方式在线路及设备上形成危险的过电压，特别是雷电过电压，雷击变电站时，会在低压供电系统及弱电系统产生很强的感应过电压，同时使变电站的地电位升高(例如：变电站的接地电阻为1 q，雷电流为10 ka，则地电位为10 kv)，因地电位升高造成对线路及设备的反击而损坏线路及设备的事件时有发生，因此，尽管变电站的外部防雷系统(避雷针引下线及接地装置)符合国家及部颁标准的要求，且其综合自动化和通信自动化等二次弱电系统也采取了诸如屏蔽、接地、隔离、滤波等措施，但却不能完全避免强大的雷电过电压及电压反击对系统造成的干扰和破坏，因此，变电站二次弱电系统内部防雷及过电压也必须采取相应的防护措施，按照iec内部防雷emp的分区，对设备的电源线、信号线、数据线等加装内部防雷及过电压器件，防止雷电感应、雷电流沿线窜人、电压反击、浪涌过电压等瞬间暂态过电压造成系统故障及损坏电子设备。浪涌过电压保护器根据其接线方式分为串联和并联两种，使用串联浪涌过电压保护器时，有可能存在由于传输信号不匹配的原因导致对传输信号有干扰的情况，特别是数据通信接口在串人浪涌过电压防护器后，会产生数据无法正常通讯。因此，在数据通讯接i：i中串人浪涌过电压防护器后，必须对数据的传输情况进行认真检查，如发现数据无法正常传输，则有可能是由于不匹配的原因导致对传输信号的干扰，应更换相匹配的浪涌过电压防护器。如果在使用浪涌过电压防护器时采用并联方式，基本上不存在上述情况，但这种接线方式对浪涌过电压防护器的技术要求更高。3 变电站系统过电压防护31 站用电系统过电压防护安装在变电站内的通信调度自动化系统大多采用交流电源或直流电源为其设备供电，在其整流环节，一般有较大容量的滤波电容，对瞬态过电压冲击有一定的吸收作用，站用变压器低压侧到站用馈电屏之间采用的是屏蔽电缆且设备都有良好的接地，运用现代防雷技术来分析，必须增加回路的分流