Research On Electrical Parameters Identification Of Direct-drive Permanent Magnet Wind Power System

Direct-drive permanent magnet wind power system has many advantages, such as large capacity, high efficiency, low maintenance cost, flexible control method, so it has a wide application prospect. The electrical parameters of wind power system will change with the variation of its working condition; which will cause adverse impact on the high performance control of the system. So the research on electrical parameters identification of direct-drive permanent magnet wind power system has great significance. The main research on this problem is as follows:The simulation model of direct-drive permanent magnet wind power system is established based on the analysis of its structure and principle; the simulation results provide basic data for parameter identification. A new identification algorithm based on multi-innovation stochastic gradient is proposed, the convergence index is introduced in order to improve the parameters estimation convergence performance of stochastic gradient algorithm. The stator resistance Rs, inductance L, permanent magnet flux ψf of permanent magnet synchronous generator and the line inductor Lg, line resistance Rg of grid-side converter are chosen as identification parameters through the analysis of their influence on the control performance of the system. According to the mathematical model of permanent magnet synchronous generator and grid-side converter, the system’s recursive identification model was established for these electrical parameters, the identification of direct-drive permanent magnet wind power system’s electrical parameters is realized by using the proposed identification algorithm.The impact of different innovation length and convergence index on the result of identification is analyzed by simulation experiment, the results provide the basis for the high performance control of direct-driven permanent magnet wind power system.