Research On Hardware-in-the-loop Of Permanent Magnet Direct-drive Wind Turbine Based On RTD

With the introduction of the "double carbon" goal,wind power has been widely utilized as a clean energy source,and wind power is one of the most mature power generation methods among renewable energy sources.Among them,permanent magnet direct-drive wind power system has been widely used in onshore wind power system by virtue of simple control,low loss,mature technology and other advantages.The wind energy utilized by wind power system is mainly provided by nature,which has the characteristics of randomness and uncertainty,etc.Enhancing the safety and stability of wind turbines is an important issue that needs to be solved urgently at present.However,most scholars currently use purely digital simulation software,which is not able to more realistically simulate the operating characteristics of the wind turbine converter controller,and does not facilitate the verification of the control method.To address this issue,this paper utilizes the Real-Time Digital Simulator(RTDS)and the control platform developed by the group to build a set of Hardware-in-the-loop(HIL)experimental platform.Firstly,the control strategy of permanent magnet direct-drive wind power system is investigated.The control method of maximum power capture is introduced.The machine-side converter realizes the decoupling control of wind power system output active and reactive power through the control strategy of speed outer loop and current inner loop,the grid-side converter realizes the stabilization of dc bus capacitor voltage through the control strategy of voltage outer loop,and the control technology of space vector pulse width modulation of voltage-type converter is analyzed.Secondly,for the traditional wind turbine HIL experimental platform has the problems of specificity and idiosyncrasy,this paper builds a generalized wind turbine HIL experimental platform,which is more generalized than the traditional wind turbine HIL experimental platform.According to the control strategy in the RTDS all-digital real-time simulation,to verify the effectiveness of the control strategy.The HIL experimental platform is constructed by hardware and software,the model is constructed according to the control strategy in the control platform,the main circuit model of the permanent magnet direct drive wind power system is constructed in RTDS,and then real-time simulation of HIL is carried out,and the full digital real-time simulation of RTDS and HIL simulation are carried out respectively for multiple working conditions,and the accuracy and feasibility of the HIL platform are further verified through waveform comparison and simulation error analysis.Finally,for the problem of unstable output power of permanent magnet directdrive wind power system in the case of grid voltage imbalance or asymmetrical fault,in order to maintain the stability of the output power of the wind power system,the positive-sequence and negative-sequence current decoupling algorithm is optimized based on the positive-sequence and negative-sequence current decoupling algorithms to eliminate the negative-sequence currents,and the grid-connected adaptability of the wind power system is significantly improved.The rationality and effectiveness of the method are verified by HIL platform.