玉树与青海主网330kV联网工程系统调试仿真研究及预控策略分析

Simulation on System Commissioning for Interconnection Project of 330 kV Qinghai Power Grid With 110 kV Yushu Power System and Analysis on Its Pre-Control Strategy

玉树与青海主网330 kV联网工程输电距离长,受端110 kV玉树电网网架结构薄弱,工程调试期间存在系统电压越限和频率稳定问题。为此,提出投切330 kV空载线路操作和SVC设备调试试验操作的电压预控方案,解决了工程调试期间玛多—玉树空载线路投切以及玉树站35 kV SVC设备带电投切时的系统电压越限问题,并用实测数据验证了上述电压预控方案的有效性。仿真分析并列试验操作对开关两侧母线电压和玉树机组无功出力的影响,提出了玉树与青海主网并列试验的预控策略。分析玉树电网水电机组调速系统参数、负荷模型以及解列点潮流对解列后玉树电网频率变化的影响,提出了玉树与青海主网解列试验的预控策略。上述电压预控方案和并、解列预控策略已应用于实际联网工程调试试验中。

There are difficulties in the interconnection project of 330 kV Qinghai power grid with 110 kV Yushu power system such as long transmission distance, weak structure at receiving end in 110 kV Yushu power system, system voltage out-of-limit and frequency instability during the commissioning. For this reason, a voltage pre-control scheme for energizing operation of no-load 330 kV transmission line and the commissioning test of 35 kV SVC in Yushu power system is proposed to solve the out-of-limit of system voltage caused by energizing operation of no-load transmission line from Maduo to Yushu and hot-line switching of 35 kV SVC in Yushu substation during the commissioning, and the effectiveness of the proposed voltage pre-control scheme is validated by measured data during the commissioning. The impacts of connection test on bus voltages at both sides of the circuit breaker and reactive output of Yushu hydropower generating units are simulated and the pre-control strategy for connection test of 330 kV Qinghai power grid with Yushu power system is put forward. The impacts of speed regulation system parameter of hydropower generating units in Yushu power system, load model of the Yushu power system and the power flow at the disconnection-point on frequency variation in post-disconnection Yushu power system are analyzed, and the pre-control strategy for the disconnection test between Qinghai power grid and Yushu power system is given. Above-mentioned voltage pre-control scheme and the pre-control strategy for system connection as well as the pre-control strategy for system disconnection have been applied in the commissioning test of actual power grid interconnection.