大型异步互联电网中送端电网频率偏差峰值计算

Frequency Deviation Peak Calculation of Sending-End Network in Large Asynchronous Interconnected Power Grid

大型区域电网通过直流异步互联之后,电网功角稳定性得到提升,但在送端电网一侧,外送直流故障会造成电网频率升高,引发频率稳定问题。在电网频率稳定性研究中,电网频率偏差峰值是一个重要指标。针对电网频率偏差峰值的计算,首先通过单机系统得出基于电网频率偏差变化率的电网频率偏差峰值计算方法;接着将该方法拓展到实际电网的频率偏差峰值计算,并分析了频率偏差峰值计算在直流附加控制与稳控切机中的应用;最后通过单机系统和云南电网算例进行仿真验证。仿真结果表明,基于频率偏差变化率的频率偏差峰值计算结果准确,适用于实际电网,具有工程实用价值。

The power angle stability of the large area power grid is improved through the HVDC asynchronous connection. But on the side of the sending-end,the DC fault makes the frequency of gird increase,which will cause frequency stabilization problem. The frequency deviation peak is an important index in the study of the power grid frequency stability. The method of calculating the frequency deviation peak based on the rate of the frequency deviation is obtained from the single machine model. Then,the method is expanded to the actual power system and the application of the method in the HVDC additional control and generator-tripping is studied. Finally,a single machine model and Yunnan Power Grid are simulated to verify the method. The results showthat the frequency deviation peak method based on frequency deviation rate is accurate and can be applied to the actual power grid,which has the practical value of engineering.