新疆与西北主网互联后电网小干扰稳定性和系统扰动试验特性

新疆电网以750 kV电压等级线路接入西北主网后,互联电网的动态特性、振荡模式发生了变化,新增了一个新疆电网对西北主网的区域间振荡模式。新疆内部和西北主网内部主要断面的动态稳定水平没有下降,新疆电网内部局部地区仍存在弱阻尼振荡模式。通过协调优化新疆电网内部北疆西部地区部分机组的励磁系统自动电压调节器(automatic voltage regulator,AVR)和电力系统稳定器(power system stabilizer,PSS)参数,可提高系统的阻尼水平,并在一定程度上解决了该地区水电窝电现象。开展了实际互联电网系统扰动试验,实测数据验证了仿真计算结果的准确性,通过扰动试验掌握了互联电网的动态特性和系统阻尼水平。研究综合运用了时域和频域的方法,并以频率计算为主,辅以时域分析校验。

Small Signal Stability of Xinjiang Power Grid Interconnected With Northwest China Power Grid and Characteristics of Its Field System Disturbance Tests

After the interconnection of Xinjiang power grid with Northwest China power grid by 750kV transmission line,dynamic characteristics and oscillation modes of the interconnected power grid are varied,and a new inter-area oscillation mode between Xinjiang power grid and Northwest China power grid appears.Dynamic stability level of the main tie line inside Xinjiang power grid and that inside Northwest China power grid are maintained,however,the oscillation mode with weak damping still exists in the northwest part of Xinjiang power grid.By means of coodinative optimization of AVR paramters and PSS parameters of partial units in West Xinjiang region the damping level of Xinjiang power grid can be improved,and the problem that it is hard to outwards transmit hydropower generated in North Xinjiang is solved to a certain extent.Field system disturbance tests of the interconnected power grid are performed,and the accuracy of simulation results are verified by measured data of actual system disturbance tests.Through disturbance tests,both dynamic characteristics and system damping level of interconnected power grid are mastered.In this research the time-domain method and frequency-domain method are synthetically utilized and the frequency-domain method is taken as the principal,and the time-domain analysis is used for the verification.