特高压线路高抗补偿方案研究

Research on high-voltage reactor compensation of UHV AC transmission lines

高抗作为特高压线路的重要无功设备,其配置直接决定了特高压系统的安全稳定运行。为此,研究了各种高抗补偿方式的适用范围。研究表明,单端补偿方式的适用于补偿前仅有一端接地甩负荷之后工频过电压超标的线路,以及工频过电压未超标、但潜供电流超标的换位线路;而两端补偿方式的优势在于可限制线路两端甩负荷工频过电压;长度超过550km的线路,宜采用分段补偿方式。提出了确定高抗补偿方案的系统方法,该方法在考虑工频过电压限制的前提下,兼顾工频过电压限制、潜供电流限制、空载线路电压控制、避免产生谐振过电压、电抗标准容量以及利于线路输送大功率时无功平衡等方面对高抗补偿度的要求,并通过实例对该方法进行了说明。

As one of the most important reactive power compensation equipment, the configuration of the high-voltage reactor determines the safety and stability of UHV system. So the application range of high-voltage reactor＇s compensation mode has been studied. Results show that single-junction compensation mode is suitable for two kinds of lines： the transposed lines only one of whose endpoint throw-off can cause excessive power frequency overvoltage, and transposed lines whose power frequency over-voltage is within the limit but secondary arc current exceeds the limit. Two-junction compensation mode can restrict the power frequency over-voltage caused by load throw-off at both endpoints of line. Sectional compensation can be used in lines more than 550 km in length. The systematic determination of high-voltage reactor compensation program is given and explained with the practical example. This method considers the power frequency overvoltage restriction, and also gives attention to the requirements of the secondary arc limit, no-load voltage controlling, resonance overvoltage prevention, high-voltage reactor standardization, and reactive power balance when transmitting high power is considered.