大规模风火电源打捆的特高压交直流混联外送系统运行特性分析

Analysis on Operation Characteristics of Large-Scale Wind-Thermal-Bundled UHV AC-DC Hybrid External Transmission System

针对新能源弱惯量、出力波动大、无功支撑能力差,严重影响弱同步支撑的送端电网暂态稳定特性及安全稳定运行的问题,采用PSASP(Power System Analysis Software Package)分析工具,以锡林浩特地区特高压交直流输电工程送端电网为对象,研究了大规模风电集中接入后,交直流系统与风火电源的交互作用以及系统暂态稳定性。搭建了典型风火电源打捆的交直流混联外送系统模型,对不同风电出力占比情况下系统发生交流短路故障、直流双极闭锁故障时的暂态稳定性进行仿真分析,得出了风电出力占比的提高将削减火电机组注入系统的暂态加速能量,提高系统暂态功角稳定性的结论。

In view of the characteristics of new energy, such as weak inertia, large output fluctuation and poor reactive power support capacity, which seriously affect the transient stability characteristics and the safe and stable operation of the sending end power grid with weak synchronous support, this paper uses PSASP(power system analysis software package)analysis tool and takes the sending end power grid of Xilinhot UHV AC/DC transmission project as the research object, the model of typical wind and thermal power bundled AC/DC hybrid external transmission system is built, the interaction between AC/DC system and wind-thermal power supply and the analysis method of system transient stability after large-scale wind power centralized access are deeply studied, and the transient stability of the system under AC short-circuit fault and DC bipolar locking under different proportion of wind turbine power is simulated and analyzed. It is concluded that the increase of the proportion of wind turbines power will greatly reduce the transient acceleration energy injected into the system and improve the transient power angle stability of the system, which plays a guiding role in reasonably arranging the operation mode of power grid and promoting the consumption of clean energy.