| The proportion of wind power connected to the grid in China is increasing in the context of "carbon peaking,carbon neutral",but the large-scale wind power connected to the grid has also increased the impact on the stability of the power system,when the detailed model of wind farms numerical simulation,there are problems such as complex model structure,workload,and even do not get simulation results,which is not conducive to the study of wind farms.Research,therefore equivalence modelling of wind farms is needed to solve this problem.Wind turbines with permanent magnet synchronous generator(PMSG)are one of the most widely used types of wind turbines,and the guidelines for grid-connected wind power require them to have high voltage ride-through(HVRT)control capability.Therefore,this paper proposes a HVRT control strategy for wind turbines with PMSG that takes into account the speed limit,in order to address the problems of traditional wind turbines with PMSG such as overspeed off-grid.On the basis of this paper,the equivalence modelling study of PMSG wind farms with HVRT control capability is carried out,and the equivalence modelling study of PMSG wind farms with HVRT control capability is proposed,which has theoretical significance and practical value for the analysis of the stable operation of power systems containing wind power connected to the grid.Firstly,this paper analyses the existing HVRT control methods for wind turbines with PMSG and the equivalent modelling methods for PMSG wind farms,and builds a mathematical model of wind turbines with PMSG by analysing the working principle and operating characteristics of wind turbines with PMSG.This paper also introduces and analyses the control methods of the main control systems of wind turbines with PMSG,laying the foundation for the development of HVRT control strategies and the study of the equivalent modelling of PMSG wind farms in the later sections.Secondly,through the analysis of the HVRT transient characteristics of wind turbines with PMSG,which has led to an understanding of the main problems to be solved by HVRT,and the HVRT control strategy of wind turbines with PMSG is proposed based on the combination of rotor energy storage and unloading resistors,which can not only suppress the overspeed off-grid of wind turbines with PMSG,but also make the rotor energy storage work to the maximum extent,and at the same time it also reduces the DC-side capacitance voltage through the synergistic cooperation of the converters on both sides of the machine network,protecting the DC-side capacitance safety and reducing the unloading resistance input.Based on the PSCAD/EMTDC simulation platform,a simulation system for the networked operation of a 1.5MW wind turbine with PMSG was built to verify the effectiveness of the proposed HVRT control strategy.Finally,based on the proposed HVRT control strategy for wind turbines witn PMSG,a PMSG wind farm HVRT equivalence modelling method considering the speed limitation is proposed based on the proposed HVRT control strategy of wind turbines with PMSG to address the shortcomings of the existing PMSG wind farm equivalence modelling methods.The S-FCM clustering algorithm,which combines the SOM and FCM algorithms,is used to equivalently model PMSG wind farms using the active power of the turbine,i.e.the active power rectification value during HVRT and the optimal power before failure as the clustering index.Based on the PSCAD/EMTDC simulation platform,a wind farm simulation model with 33 wind turbines with PMSG was built.The results show that the equivalence model is able to characterise the output power characteristics of the wind farm more accurately and validate the reasonableness and effectiveness of the proposed HVRT equivalence modelling method for PMSG wind farms considering the speed limit. |
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