风火打捆比例对直流孤岛系统稳定性影响的研究

摘要

风火打捆特高压直流外送是未来开发全球清洁能源资源的重要方式之一,其稳定特性研究值得重视.从跟随风电功率变化的角度提出了风电与火电容量配比方案,然后在考虑风电出力概率的基础上提出了不同的配比方案.通过仿真对比分析研究了两种风火配置比例对送端孤岛系统稳定性的影响.结果表明:风火打捆比例由1:2降低为1:1.5后,送端电源调节能力和等值机械转动惯量有所降低,直流系统发生故障失去部分功率后,系统频率上升幅度和系统功角首摆幅度相应增加,增大了系统失稳的风险.%Wind-thermal-bundled power transmission by UHVDC system is regarded as one of feasible ways on development of global clean energy in the future and its characteristics of stability should be paid attention to.Different wind-thermal installed capacity ratio is proposed with the wind from the change of power angle and in consideration of the probability for wind power output.The effect of two kinds of proportion on the stability of the sending end islanded system is comparatively analyzed by the simulation.Regulating ability of sending end power and equivalent mechanical rotational inertia would be lower when wind-thermal installed capacity ratio decreased from 1:2 to 1:1.5.Under DC power system disturbances and loss of parts of power,there is a slight increase in ascending amplitude of system firequency and power-angle fluctuation,risk of system destabilization will rise accordingly.