澜沧江上游梯级水电站送出方案的无功配置研究

针对澜沧江上游梯级水电站500kV出线线路总长度较长,充电功率较多,但水电站出线长度普遍较短的情况,提出了3种梯级电站无功配置方案。通过电力系统潮流稳定计算分析软件BPA对3种无功配置方案下水电站附近区域电网电压进行仿真计算,结果表明若仅靠常规的线路高抗配置方案将可能导致系统电压偏高需要水电站进相,若采用短线路过补偿方式则可能引起的工频谐振过电压等问题,难以满足系统调压要求。推荐的无功配置方案考虑在合适的澜沧江梯级水电站母线侧装设500kV高压电抗器,高压电抗配置补偿率合理,能够较为合理地控制系统电压。

Reactive Power Allocation of Power Transmission Scheme for Cascade Hydropower Stations in Lancangjiang River

Because the cascade hydropower stations locating at the upstream of Lancangjiang River have such features as long 500kV outgoing transmission line,large charging power and generally short outgoing lines of hydropower stations,three kinds of reactive power allocations of cascade hydropower stations are presented.Through simulation and calculation on voltage of regional power grid near hydropower stations for the three reactive power allocation schemes are carried out by using of power flow stability calculation and analysis software of the electric power system(BPA),the results show that only normal allocation scheme of high-voltage shunt reactor on transmission lines may cause higher system voltage and need the phase-lead operation of the plants.In addition,if over compensation method for short-length transmission line is applied,the problems such as resonance at normal supply frequency and overvoltage will occur,which is hard to meet the requirement of system voltage regulation.The recommended reactive power allocation scheme is that high-voltage shunt reactor is installed on the 500kV bus-bar of the plants,which has reasonable compensation ratio and can control the system voltage.