半波长交流输电线路电容调谐分析

Analysis on Capacitance Tuning System of Half-wavelength AC Power Transmission Lines

采用半波长交流输电方式时,当线路的自然长度不足半个波长时,需要对电气波长进行人工调谐。基于传输线理论模型的电容调谐网络,要求调谐电容必须均匀分布在整个输电线路上,根据半波长输电条件(即线路的电气长度等于1个工频半波)推导出调谐电容值计算公式,并结合某1 000 k V交流输电线路参数,分别仿真不同调谐电容数时的调谐效果。结果表明,并非补偿点数量越多,调谐效果就越好。当调谐电容数达到8时,调谐效果趋于稳定,即满足了半波长输电要求,同时使得调谐电容数目最少。

If the practical line length between its two ends is shorter than half wavelength when half-wavelength AC power transmission （HWACT） technology is used, appropriate technology should be employed to tune the electrical length manually. Based on the model of transmission line theory, the capacitance tuning network requires the tuning ca- pacitance to be evenly distributed over entire line. In this paper, the formula for calculating tuning capacitance value is deduced based on the condition of HWACT that the electrical length of the line is equal to a half-wave of power frequency. Integrating with actual parameters of a certain 1 000 kV AC transmission line, the tuning effects under different numbers of tuning capacitances are simulated. The simulation result shows that the more capacitance pointo does not means better tuning effect. When the number of tuning capacitances reaches eight, the tuning effect begins to stabilize, which meets the requirements of HWACT and makes the minimum number of tuning capacitances.