变流器开路故障下永磁同步风力发电系统运行特性分析

Characteristic Analysis for Permanent Magnet Synchronous Generator Wind Power Systems During Converter Faults

永磁同步风力发电系统(permanent magnet synchronous generator power system,PMSG系统)变流器开路故障时的运行特性分析,因系统的非线性性与强耦合性影响难以深入。在剖析PMSG系统电压特性的基础上,提出了一种定子电流分析方法。详细推导故障相定子电压、下管电压及直流侧对地电压在断流和续流时的数学解析式,揭示了故障时各电压的运行特征;进一步结合混合逻辑动态(mixed logic dynamic system,MLD)理论,建立PMSG系统MLD健康模型,并利用电流残差中系统耦合特性以及非线性性,体现了故障后定子电流的动态变化特性。仿真和实验结果证明了理论分析的正确性,也证实了所提方法能有效解决PMSG系统非线性性和强耦合性对定子电流分析的影响。

The characteristic analysis of Permanent magnet synchronous generator power systems (PMSG)conducts difficultly for its nonlinearity and strong coupling.This paper proposed a novel analysis method for PMSG currents on basis of the voltage feature research in depth.Stator voltages,lower tube voltages and the voltage between DC-link and ground in the faulty phase were analyzed under the cutout or continuous flowing PMSG currents.This analysis was deduced,and obtained the mathematical expressions of each voltages.So the operation features of voltages were shown.Moreover,adopting mixed logic dynamic model (MLD),a MLD health model of PMSG was built.And an analysis method of the stator current was proposed on basis of residual errors which contained the nonlinear and coupling feature of PMSG.Both the experiment and simulation results,which prove the correctness of theoretical analysis,also verify that it can solve the difficulty of strong nonlinearity and coupling in PMSG systems.