1、英文原文Research on Lightning Over-voltage Protection for500kV GIS SubstationAbstractThis paper combines incoming lines with 500kv GIS substation, considering the influence of the impulse voltage-second characteristics of insulator strings, the impulse corona of incoming lines, the impulse grounding res
2、istance of tower and the position of lightning. ATP-EMTP simulation program is applied to analyze the lightning over-voltage of 500kv GIS substation. The result shows that impulse corona and the resistance of tower which is close to the substation have great influence on over-voltage, when lightning
3、 strike the tower which is close to terminal door-typed structure, the lightning over-voltage may be not the most serious, and when the over-voltage of the equipment is very serious, a group of arrester is installed which can decrease the over-voltage effectively. This research thinking takes safety
4、 and economy into account, which can provide new reference for the engineering.Key words-GIS substation; impulse corona; grounding resistance;position of lightning; over-voltage.I. INTRODUCTION With the 500kV power transmission project construction and development, the electric power scientific rese
5、arch and design units are gradually in depth study and test, calculation and analysis of lightning incoming surge protection of 500kV substation as an important part has also made great progress. However, a number of scheme is not practical, some of them just over-emphasis on insulation margin not c
6、onsidered from the view of economic; some only through unilateral calculation gives scheme which left hidden troubles for safety. The 50% discharge voltage of insulator string as invaded wave was selected as in literature , such that method to select is not recommended because the impulse voltage-se
7、cond characteristics of insulator strings change with time. The impulse grounding resistance of tower and impulse corona was ignored as in reference , according to the actual situation in view, the model appears to be conservative and rough. The lightning strike spots was chosen 1# tower which close
8、 to door-typed structure (0# tower) as most serious to deal with, in some cases my be correct but not all cases. A large number of studies have shown that 1# tower top potential was reduced as 1# tower near 0# tower when lightning strike 1#. A large number of studies show that a large number of stud
9、ies have shown, when the lightning strike 1# tower which is next to the terminal gate-type framework, top potential of the 1# tower is reduced ,because the negative reflection wave return to the 1# tower by 0# tower , which make the overvoltage decreased. So only calculation lightning strike 1# is n
10、ot complete. This paper combines incoming lines with 500kv GIS substation, considering the influence of the impulse voltage-second characteristics of insulator strings, the impulse corona of incoming lines, the impulse grounding resistance of tower and the position of lightning. ATP-EMTP simulation
11、program is applied to analyze the lightning over-voltage effect about distant and near impact grounding resistance, the position of arrester which provide new reference for the engineering.II. MODEL FOUNDATION AND PARAMETER SELECTION ATPDraw is the most widely used on a electro-magnetic transient si
12、mulation, due to the graphic interface, makes this software convenient and accuracy by using. In this research,lightning models, transmission line models, tower model, arrester model, all of that be defined based on the characteristics of parameter, the transformer, disconnector, breaker etc, all of
13、 these can be expressed by equivalence impact entrance capacitance under the lighting wave.A. The equivalent circuit diagram of 500kV GIS Substation As shown in figure 1:this is a equivalent circuit diagram of 500kV GIS Substation, considering the security of system, “One Bus One Transformer” was ch
14、ose as the most serious running model of lighting over-voltage to simulation computation. As shown in figure: CVT is capacitor voltage transformer; DS is disconnector; CT is current transformer; CB is circuit breaker; F is arrester; T is transformer.B. Lightning Simulation Lightning current is belon
15、ging to unipolar pulse wave, Chinas standards recommended by lightning current amplitude probability distribution as follows: In this equality, I is lightning current, P is the probability of amplitude greater than I. This article taking the probability of 0.14% amplitude is 240kA wave of 2.6/50us a
16、s simulation lightning current.C. Insulator Strings Simulation As shown in Figure 2 is Insulator strings model, when the induced over-voltage is higher than voltage-second characteristics of insulator strings, the control switch will keep this export state which the part of criterion passed to 25 pi
17、eces of insulators of XP-160 style is used in this article the voltage-second characteristics of insulator strings which structure linear coefficient to close by least square method. The voltage-second characteristics as shown in table. The function of voltage-second characteristics of insulators is
18、 structured by linear regression analysis in matlab. The exponential function after calculation is that:D. Incoming line of substation simulation This article choose 2 kilometer incoming line simulation 6 tower, lightning strike TW1# , TW2#, TW3# is considered. Tower simulation: The tower which ligh
19、tning strike use natural size distributed parameter simulation, In this article the tower of wave impedance is 115, wave velocity is 210m/us. Incoming line parameter: The conductor is 4LG-300, bundle spacing is 400mm, diameter is 23.94mm, average height is 27m, arc sag is 17m, the dc resistance is 0
20、09614/km under 20m; The lightning shield line is OPGW-140A,diameter is 15.7mm, average height is 37m, arc sag is 15m, the dc resistance is 0.51/km under 20m.E. Corona Simulation In order to research the wave attenuation and distortion influence on results the corona is considered in this article. R
21、eference show that the conductance can be ignored only use dynamic capacitance to simulate the attenuation and distortion under lightning over-voltage. The combined model of TACS is used to simulation based on the lines of corona characteristics in this article, The DEVICES in Fig.3 is criterion whi
22、ch phase to phase and phase to ground to start corona.F. Parameters of arresterThe enclosed type Zno arrester is installed inside of GIS, the open type Zno arrester is installed outside of GIS. The electrical characteristics of Zno arrester shown in table.III. EFFECT OF VARIOUS FACTORS UND
23、ER LIGHTNING INCOMING SURGEA. Position of lightning strike The tower 0# to 2# is named near region tower which impulse grounding resistance is 15, The tower 3# to 6# is named far region tower which impulse grounding resistance is20. According to table.the over-voltage of lightning strike TW2# is mor
24、e serious than TW1#. In research if chose lightning strike TW1# as most serious condition to deal with is unreasonable it will bring security hidden danger.Figure 4. The wave of over-voltage on transformer when lightning strike The wave on transformer under lightning strike is shown in fig.4, then t
25、he following conclusions are drawn: the steepness of striking TW1# is greater than TW2#, the transform have different distance from the transformer, so there is a certain delay in the wave. TW1# short distance away from the substation, the lightning wave negative reflection to TW1# and reduce the ov
26、er-voltage.B. Impulse Corona To make study convenient the corona was ignored so there had a certain error. This article discuss the effect of corona in actual. When corona produced, there have volume and velocity greater difference negative and positive ions around conductor form corona envelop. The
27、 corona envelop can increase the capacitance and conductance of conductor. The wave which lightning strike TW2# considered corona as shown in fig.5Figure 5. The Voltage Waveform of Transformer The following conclusions can be found according to fig.5: There have attenuation and distortion and also h
28、ave a certain delay under corona. The maximum over-voltage value on transformer is 1152.4kV when considered corona else is 1183.2kV, the decay caused by corona is 30.8kV. Corona have favorable for over-voltage protection which can reduce the amplitude and steepness.C. Impulse Grounding Resistance of
29、 Tower In order to make study convenient, the impulse grounding resistance of TW0#TW2# expressed as near region resistance labeled as R1, and the TW3#TW6# expressed as far region resistance labeled as R2. Change R1 and R2 the over-voltage of equipment is shown in table. As shown in the table. smalle
30、r impulse grounding resistance, the lower over-voltage in equipment. When the R2 decreasing, the voltage decrease slightly; when the R1 decreasing, the voltage decrease more. For example, resistance reduce 1, the over-voltage reduce thousands of kV. Therefore, reduce near region impulse grounding re
31、sistance have great significance for limit over-voltage level and save cost.D. The position of arresterIn order to analyze the effect that the number and the position of arrester, this article calculated as follows: (1) add a set of arrester on outgoing line;(2)remove the arrester of transformer; (3
32、) remove the arrester of outgoing line; (4) remove the arrester both outgoing line and transformer. The transformer and CVT configuration model of Y10W5-420/960 arrester and The most serious condition “Single line singletransformer, lightning strike TW2#”is chose. From the table.we can conclusion th
33、at:1. Install arrester have a large extent reduce the over-voltage, once remove the arrester transformer or outgoingline the over-voltage on equipment increase significantly even exceed insulation level.2. The configuration of arrester at present, the over-voltage on transformer still very high, the
34、 insulation margin only 12.23%.3. When add a set of arrester on outgoing line, the over-voltage of equipment have decreased significantly. Theinsulation margin have rise to 24.89%.IV. CONCLUSION(1)According to the simulation in the past, it was generally believed that the over-voltage caused by ligh
35、tning strike TW1# was most serious, this paper shows that, lightning strike TW2# may have more serious. Only choice strike TW1# as the largest over-voltage to deal with is unreasonable, it will leave security hidden danger.(2) There have attenuation and distortion and also have a certain delay under
36、 corona, it is favorable for over-voltage protection which can reduce the amplitude and steepness.(3) Smaller impulse grounding resistance, the lower over-voltage in equipment. when near region impulse grounding resistance decreasing, the voltage decrease more. The resistance reduce 1, the over-volt
37、age reduce thousandsof kV. Therefore, reduce near region impulse grounding resistance have great significance for limit over-voltage level and save cost. As reference 3 ignore all of these effects will be bring a great error.(4) The over-voltage on transformer is still high according to the present
38、configuration. The over-voltage levels decrease if add a set of arrester in outgoing line. It can provide reference for the engineering.中文译文 500千伏GIS变电站的雷电过电压保护研究 摘要本文结合输电线与500千伏GIS变电站，并考虑到绝缘子串的脉冲伏秒特点的影响，脉冲电晕，杆塔接地电阻的脉冲和闪电的位置。 ATP-EMTP仿真是用来分析500千伏GIS变电站的雷电过电压。结果表明，脉冲电晕和靠近变电站的塔阻力对过电压有很大的影响，当雷击靠近码头门式结构
39、的塔，雷电过电压可能不是最严重的，而设备的过电压是非常严重的，安装避雷器组可以有效降低过电压。这研究考虑到安全和经济因素，可以为工程提供新的参考。关键词：脉冲电晕；接地电阻；GIS变电站；闪电位置；过电压。1.导言随着500千伏输变电工程的建设和发展，电力科研设计单位正在逐步深入的研究和试验，计算分析雷电侵入波保护作为500KV变电站的重要组成部分也取得了长足的进步。然而，有很多事不切实际的计划，其中一些只是过分强调保温而不从经济观点考虑，有的只是通过单方面计算给计划留下安全隐患。 50放电绝缘子串电压侵入波，但不建议选择这样的方法，因为绝缘子串的脉冲伏秒特性随时间变化。该脉冲和脉冲电晕塔接地
40、电阻忽略，根据实际情况，模型似乎是保守和粗糙的。雷击点是1 ，就选接近门型结构（0塔）为最严重的来处理，在某些情况下，是正确的，但并非对所有的案例。大量研究表明，当雷击1#塔时，1塔顶电位减少，因为1塔接近0塔。当雷击码头门式框架旁的1#塔，塔顶电位降低，因为负反射波返回到1塔附近的0塔，使过电压降低，因此，只计算雷击1是不完整的。本文结合输电线与500千伏GIS变电站，并考虑绝缘子串的脉冲伏秒特点，脉冲电晕，杆塔接地电阻的脉冲和闪电的位置。 ATP-EMTP仿真是用于分析接地电阻的远近、避雷器的位置对过电压保护的影响。2.模型的基础和参数选择ATPDraw是最广泛使用的一个电磁暂态仿真软件，
41、图形界面，使这一软件使用方便，准确。在本研究中，雷电流模拟，传输线路模拟，塔模型，避雷器模拟，并进行变压器、断路器等的参数设定，这些都可以等效模拟。 （1）500千伏GIS变电站等效电路图 如图1所示：这是一个500千伏GIS变电站等效电路示意图，考虑到系统的安全性，本文选择“车一变压器”作为雷电过电压的模型进行仿真计算。如图所示：CVT是电容电压变压器；DS是隔离开关；CT是电流互感器；CB是断路器；F是避雷器；T为变压器。 图1 500千伏变电站等效电路图 （2）雷电流模拟 雷电流属于单极性脉冲波，中国的标准推荐的雷电流幅度概率分布如下：式中：I雷电流幅值； P雷电流幅值大于等于I的雷电流
42、概率。 （3)绝缘子串仿真图2 绝缘子串模型图2所示绝缘子串模型中，当感应过电压比绝缘子串的伏秒特性高，控制开关将保持这个输出频率，伏秒特性如表一所示。 表一 500KV变电站绝缘子的伏秒特性 绝缘子的伏秒特性上表给出。计算公式是： （4）变电站输电线路仿真本文选择2公里输电线路模拟6塔，雷击塔1、塔2、塔3。杆塔模拟：雷击杆塔使用自然大小分布参数模拟，在本文中，波阻抗115，波速是210m/us。 进线参数：导线为4LG -300，档间距为400mm，直径23.94mm，平均高度为27m，弧形凹陷17米，直流电阻0.09614，避雷线为OPGW-140A，直径15.7mm，平均高度为37m，
43、弧凹陷15米，直流电阻为0.51。 （5）电晕模拟图3 电晕模型 为了研究波衰减和失真对结果的影响，文章要考虑电晕电晕。参考文献5-6表明，电导可以忽略不计。文章中TACS组合模型在电晕特性的基础上进行模拟，器件的标准如图3. （6）避雷器的参数号 GIS内部安装的是封闭式氧化锌避雷器，GIS外部安装的是开放式氧化锌避雷器。该氧化锌避雷器电气特性如表二。表二 氧化锌避雷器的电气特性3.各种因素的作用下闪电侵入波 （1）雷击位置 塔0、2被命名为近区塔冲击接地电阻15，塔36是名为远区塔冲击接地电阻20。过电压对设备的单线单根据不同的雷击变压器位置如表三所示。表三 雷击位置过电压 据表三的雷击过
44、电压杆塔2比杆塔1跟严重，如果选择研究雷击杆塔1作为最严重的情况处理是不合理的，会带来安全隐患。图4 雷击不同的塔时变压器过电压波形 雷击不同塔时变压器过电压波如图4所示，然后得出以下结论：雷击杆塔1比雷击杆塔2时，波形更陡峭，变压器不同距离变换，所以有一定的延误浪潮。 杆塔1距离变电站近，雷电波负反应杆塔1#，降低了过电压。 （2）脉冲电晕 为了使学习方便，所以忽略电晕有一定的误差。本文讨论了实际的电晕效应。当电晕产生的，有数量和速度较大的差异阴性和阳性离子导体周围形成电晕信封。电晕信封可以增加导体电容和电导。这雷击杆塔2的波形如图5所示。图5 变压器电压波形 下面的结论根据图5得出：电晕有
45、衰减和失真，也有一定的延迟。变压器最大过电压值是1152.4kV，考虑到电晕时为1183.2kV，电晕造成的衰减为30.8kV。电晕对过电压保护有利，可减少振幅和倾斜度。 （3）冲击接地电阻塔 为了使学习方便，杆塔0杆塔2的脉冲接地电阻表示近区，标记为R1，杆塔3杆塔6表示为远区，标为R2。改变R1和R2的过电压设备如表四。表四 不同接地电阻的过电压 如图所示，冲击接地电阻较小，设备的过电压也较小。当R2降低，电压略有下降，当R1降低，电压下降更多。例如，电阻减少1，过电压降低千伏。因此，减少近区冲击接地电阻对限制过电压，具有重大意义和保存成本。 （4）位置避雷器为了分析避雷器的位置和数量的影
46、响，本文计算如下： （1）装设一系列输出线路避雷器； （2）删除变压器避雷器； （3）除去输出线路避雷器； （4）删除输出线路避雷器和变压器避雷器。 该变压器和电容式电压互感器配置模型的Y10W5-420/960避雷器和最严重的状况“单线单变压器，雷击杆塔2”是被选中的。表五 从表五中可以得出结论是： （1)安装避雷器在很大的程度上减少过电压，如果删除变压器和输电线路避雷器设备过电压将会显著增加，甚至超过绝缘水平。 （2）目前，我们避雷器的配置，变压器上的过电压仍然非常高，绝缘只缘12.23。当添加输电线路避雷器设置，设备过电压明显下降。该绝缘保证金已上升到24.89。4 结论 （1）根据过去的仿真，一般认为，由雷击造成的过电压杆塔1#最为严重，本论文表明，雷击杆塔2可能更为严重。只选择选择杆塔1#作为最大的过电压来处理的是不合理的，会留下安全隐患。 （2）电晕有衰减和失真，也有一定的延误，它有利于过电压保护，这可以降低的幅度和陡度。 （3）规模较小的接地电阻，降低设备的过电压。近区冲击接地电阻降低，电压下降更多。1的阻力减少，过电压降低千伏。因此，减少近区冲击接地阻力对限制过电压水平和节约成本有重大意义。正如文献3忽略这些影响都将带来极大的误差。 （4）变压器过电压仍高与本配置。如果在输电线路上装设避雷器设置，可以降低过电压水平。它可以为工程提供参考。
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