弱交流系统下直驱风电场次同步振荡特性分析  

Analysis of SSO characteristics of D-PMSGs based wind farm under weak AC system

作　　者：万强 贾祺[1] 严干贵[1] Wan Qiang;Jia Qi;Yan Gangui(Northeast Electrical Power University,Department of Electrical Engineering,Jilin 132012,China)

机构地区：[1]东北电力大学现代电力系统仿真控制与绿色电能新技术教育部重点实验室

出　　处：《可再生能源》2019年第8期1171-1178,共8页Renewable Energy Resources

基　　金：国家自然科学基金项目(51277024)

摘　　要：针对弱交流系统下直驱风电场发生次同步振荡问题,建立了直驱永磁风机风电场的电磁暂态等值模型,分析了接入交流系统的强度、风机并网台数、风机控制参数以及静止无功发生器的控制方式对次同步振荡特性的影响。分析结果表明:随着交流系统强度的降低和风机台数增加,次同步振荡频率逐渐向低频段转移,且振荡幅值增大;一定范围内,随着d轴电流内环比例参数增大,系统不易发生次同步振荡,而积分参数增大,次同步振荡频率减小,幅值增大;静止无功发生器(SVG)采用并网点电压幅值控制,比恒定的无功功率控制更容易使直驱风电场发生次同步振荡;最后,搭建三机并联的直驱风电场仿真模型,分析比较了不同运行工况、控制参数下和单机等值模型的差异性。Aiming at the problem of sub-synchronous oscillation(SSO)of the direct-drive permanent synchronous generators(D-PMSGs)based wind farm under weak AC system,the electromagnetic transient equivalent model of the D-PMSGs based wind farm is established.This model is used to study the influence of AC system strength,online number of D-PMSGs,the control parameters of D-PMSGs and control methods of static var generator(SVG)on SSO characteristics.The results show that with increasing of online number of D-PMSGs and decreasing of AC system strength,the SSO frequency decreases and magnitude increases.Within a certain range,when the integral parameter of the active current inner loop increases,the frequency of SSO decreases and the increasing of proportional parameter has little effect on SSO,when it reaches certain value,the system operates stably.When the SVG uses the grid-connected voltage amplitude control instead of the constant reactive power control,D-PMSGs based wind farm is more likely to oscillate.Finally,the simulation model of the three-machine parallel D-PMSGs based wind farms is built and compared to the single-machine equivalent model in different conditions and control parameters.

关 键 词：直驱风电场 次同步振荡 弱交流系统 

分 类 号：TK51[动力工程及工程热物理—热能工程]