高电压技术第2版 吴广宁9.7.ppt

9.7.1 绝缘配合的原则与方法 9.7.1 Principles and methods of insulation coordination 9.7.2 变电站电气设备绝缘水平的确定 9.7.2 Determination of insulation level of substation electrical equipment 9.7.3 架空输电线路绝缘水平的确定 9.7.3 Determination of insulation level of overhead transmission line,9.7 绝缘配合 9.7 Insulation Coordination,电力系统的运行可靠性主要由停电次数及停电时间来衡量造成停电的主要原因之一是绝缘的击穿，因此电力系统运行的可靠性，在很大程度上取决于设备的绝缘水平和工作状况在不过多增加设备投资的前提下，如何选择采用合适的限压措施及保护措施，就是绝缘配合问题9.7.1 绝缘配合的原则与方法 9.7.1 Insulation Coordination Principles and Methods,The reliability of power system operation is mainly determined by power outage frequency and outage time. One of the main reasons for power outages is insulation breakdown. So the reliability of power system operation depends largely on the equipment, insulation levels and working conditions. How to choose a suitable pressure limiting measures and protective measures without more investment in equipment is insulation interface problems.,1. 绝缘配合的原则 The principle of insulation coordination,原则：根据设备在系统中可能承受的工作电压及过电压，考虑限压装置的特性和设备的绝缘特性来确定必要的耐受强度，以便把作用于设备上的各种电压所引起的绝缘损坏和影响连续运行的概率，降低到在经济上和运行上能接受的水平。

Principle: According to the operating voltage and over-voltage the device in the system may have to bear ,meanwhile considering the characteristics of the pressure limiting device and equipment necessary insulating properties to determine the tolerance of strength in order to act on a variety of voltage equipment insulation damage caused by and influence the probability of continuous operation, reduced to the economic and running on the acceptable level.,要求： Requirements: 在技术上处理好各种电压、限压措施和设备绝缘耐受能力三者之间的配合关系； Technically it should handle a variety of voltage, current limit measures and equipment insulation voltage tolerance of the cooperation between the three relationships; 在经济上协调设备投资费、运行维护费和事故损失费（可靠性）三者之间的关系。

The coordination of equipment investment in economic costs, operation and maintenance costs and accident damage costs (reliability) among relations should be good.,电气设备绝缘水平的确定 Determination of electrical equipment insulation level,在330kV及以上的超高压绝缘配合中，考虑到设备在运行时要承受运行电压、工频过电压及操作过电压，对电气设备绝缘规定了短时工频试验电压，对外绝缘还规定了干状态和湿状态下的工频放电电压； In the 330kV EHV and above short-term frequency test voltage dry state and wet state of the power frequency discharge voltage are fixed by taking into account the device at run time to bear the operating voltage, power frequency over-voltage and over-voltage.,考虑到在长期工作电压和工频过电压作用下内绝缘的老化和外绝缘的抗污秽性能，规定了设备的长时间工频试验电压； Taking into account the long-term voltage and power frequency over voltage within the insulation under the outer insulation aging and anti-contamination performance of the equipment provided long-frequency test voltage; 对于220kV及以下的设备和线路，考虑到雷电过电压对绝缘的作用，规定了雷电冲击试验电压等。

For the 220kV and below ,the equipment and lines, taking into account the lightning over-voltage on the insulation's role, provi ding lightning impulse test voltage.,从电力系统绝缘配合的发展阶段来看，大体经历了三个过程： Three processes has undergone in the power system insulation coordination development :,（1）多级配合 Multi-level complement (Before 1940) 由于当时所用的避雷器保护性能及电气特性较差，不能把它的特性作为绝缘配合的基础，因此采用多级配合的方法 At that time, due to the poor performance of surge arresters ,it can not be adopted as the foundation. So a multi-level coordination had been developed.,2. 绝缘配合的方法 Insulation coordination approach,多级配合的原则：价格越昂贵、修复越困难、损坏后果越严重的绝缘结构，其绝缘水平应选的越高。

Principles of Multi-level coordination : The more expensive ,more difficult to repair, more serious damage of the insulation structure, the insulation levels should be designed better.,多级配合的缺点：由于冲击闪络和击穿电压的分散性，为了使上一级伏秒特性的下限高于下一级伏秒,采用多级配合的方法会把处于图9-17中最高位置的内绝缘水平提得很高Disadvantages of multi-level coordination : due to the impact of flashover and breakdown voltage of the dispersion, in order to limit the V-s characteristics is higher than under a volt-second, using multi-level approach will meet in the Figure 9-17 in the the highest position within the insulation level to a high level.,图9-17 变电站绝缘水平的四等级示意图 Fig 9-17 Substation insulation level of the four-level diagram,（2）惯用法 Common methods 按作用于绝缘上的最大过电压和最小绝缘强度这两个随机变量进行配合。

采用这一原则时，常要求有较大的安全裕度，且不能定量地估计可能的事故率Coordination is determined by two random variables including maximum over-voltage and minimum insulation strength. A larger margin is required for safety in application of this principle. And it can not estimate the potential of the accident rate quantitatively.,确定电气设备绝缘水平的基础是避雷器的保护水平雷电或操作冲击电压对绝缘的作用可按图9-18用工频耐压试验等价The protection level of surge arresters is the basis of determination in the electrical equipment insulation level. Lightning impulse voltage of the insulation is equivalent to the frequency voltage withstand test according to Figure 9-18 .,图9-18 确定工频试验电压 Fig 9-18 Determine the test voltage in working frequency,“统计法”：根据过电压幅值和绝缘的耐电强度都是随机变量的实际情况，在已知过电压幅值和绝缘闪络电压的概率分布后，用计算的方法求出绝缘闪络的概率和线路的跳闸率，在进行了技术经济比较的基础上，正确地确定绝缘水平。

“Statistics Law“: Over-voltage amplitude and insulation resistance of electrical strength are random variables. When over-voltage and insulation flashover voltage amplit。