變電站系統(tǒng)過電壓防護技術.doc

附錄附錄A外文資料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 protectionIn 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 designIEC (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 protection3.1 points over-voltage electricity system protectionSubstation 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 withFor 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 powerCommissioner Office.3.2 integrated automation system over-voltage protectionProtective 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 protectionProtection 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 protectionCommunication 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 protectionProtective 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 protectionA 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 protectionProtective 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. From: /p-144919607.html變電站系統(tǒng)過電壓防護技術變電站的過電壓保護是以電子信息系統(tǒng)為保護核心，為被保護設備構建一個均壓等電位系統(tǒng)，并通過各級過電壓浪涌保護器逐級把電流泄放入大地，使變電站設備安全和可靠地運行。1 變電站過電壓防護近年來，變電站的通信、通信系統(tǒng)、繼電保護系統(tǒng)、后臺管理模塊經常發(fā)生過電壓損毀事件，究其原因主要是其相關系統(tǒng)和弱電產品過電壓防護水平較弱，甚至根本沒有過電壓防范技術措施，其后果對電網的安全運行帶來了較大負面影響。隨著綜合自動化系統(tǒng)和通信自動化系統(tǒng)等二次弱電系統(tǒng)在變電站的廣泛應用，這類電子系統(tǒng)(設備)元器件的集成度愈來愈高，信息存儲量愈來愈大，速度和精度不斷提高，而工作電壓只有幾伏，信息電流僅為微安級，因而對外界干擾極其敏感，特別對雷電等電磁脈沖和過電壓的耐受能力很低。當雷電等過電壓和伴隨的電磁場達到某一閥值時，輕則引起系統(tǒng)失靈，重則導致設備或其元器件永久性損壞。盡管雷電直擊電子系統(tǒng)(設備)的可能性不大，但是雷擊附近大地、建筑物、交流供電線路和空中雷云放電時直接形成的，或者由于靜電感應及電磁感應形成的沖擊過電壓，都有可能通過與之相連的電力線路、信號線路或接地系統(tǒng)，通過各種接口，以傳導、耦合、輻射等形式，侵入電子系統(tǒng)(設備)并釀成嚴重的干擾或事故。因此，加強和改進電子系統(tǒng)(設備)的防護，盡量減小其遭受雷電等沖擊干擾損害造成的直接損失和間接損失，已成為當今亟待解決的問題。2 過電壓保護設計IEC(國際電工委員會)TC81技術委員會將防雷分為外部防雷和內部防雷兩個部分，外部防雷是指避雷針(或避雷帶、避雷網)、引下線和接地系統(tǒng)，是被保護物體免受直接雷擊；內部防雷則是防止雷電和其他內部過電壓侵入設備造成的毀壞。一個完善的防雷及過電壓保護系統(tǒng)必須綜合運用泄流(分流)、均壓(等電位)、屏蔽(隔離)、接地、限壓(箝位)保護等各項技術，按照外部防雷和內部防雷的原則，根據防護對象的特點，靈活應用，采取具體措施，構成一個完整的防護體系。變電站內的過電壓形式主要有：雷電過電壓、工頻過電壓及諧振過電壓、操作過電壓等，這些過電壓以傳導或電磁感應的方式在線路及設備上形成危險的過電壓，特別是雷電過電壓，雷擊變電站時，會在低壓供電系統(tǒng)及弱電系統(tǒng)產生很強的感應過電壓，同時使變電站的地電位升高(例如：變電站的接地電阻為1 Q，雷電流為10 kA，則地電位為10 kV)，因地電位升高造成對線路及設備的反擊而損壞線路及設備的事件時有發(fā)生，因此，盡管變電站的外部防雷系統(tǒng)(避雷針引下線及接地裝置)符合國家及部頒標準的要求，且其綜合自動化和通信自動化等二次弱電系統(tǒng)也采取了諸如屏蔽、接地、隔離、濾波等措施，但卻不能完全避免強大的雷電過電壓及電壓反擊對系統(tǒng)造成的干擾和破壞，因此，變電站二次弱電系統(tǒng)內部防雷及過電壓也必須采取相應的防護措施，按照IEC內部防雷EMP的分區(qū)，對設備的電源線、信號線、數(shù)據線等加裝內部防雷及過電壓器件，防止雷電感應、雷電流沿線竄人、電壓反擊、浪涌過電壓等瞬間暫態(tài)過電壓造成系統(tǒng)故障及損壞電子設備。浪涌過電壓保護器根據其接線方式分為串聯(lián)和并聯(lián)兩種，使用串聯(lián)浪涌過電壓保護器時，有可能存在由于傳輸信號不匹配的原因導致對傳輸信號有干擾的情況，特別是數(shù)據通信接口在串人浪涌過電壓防護器后，會產生數(shù)據無法正常通訊。因此，在數(shù)據通訊接I：I中串人浪涌過電壓防護器后，必須對數(shù)據的傳輸情況進行認真檢查，如發(fā)現(xiàn)數(shù)據無法正常傳輸，則有可能是由于不匹配的原因導致對傳輸信號的干擾，應更換相匹配的浪涌過電壓防護器。如果在使用浪涌過電壓防護器時采用并聯(lián)方式，基本上不存在上述情況，但這種接線方式對浪涌過電壓防護器的技術要求更高。3 變電站系統(tǒng)過電壓防護31 站用電系統(tǒng)過電壓防護安裝在變電站內的通信調度自動化系統(tǒng)大多采用交流電源或直流電源為其設備供電，在其整流環(huán)節(jié)，一般有較大容量的濾波電容，對瞬態(tài)過電壓沖擊有一定的吸收作用，站用變壓器低壓側到站用饋電屏之間采用的是屏蔽電纜且設備都有良好的接地，運用現(xiàn)代防雷技術來分析，必須增加回路的分流措施，因