Research On Fault Crossing Control Strategy Of Doubly Fed Wind Power Generator

In modern society,energy consumption has intensified,the mode of power generation based on fossil fuels is undergoing transformation,and the proportion of energy generation from sustainable development is gradually increasing.Among many new energy generation methods,photovoltaic power generation and wind power generation are the two main components,of which wind power generation accounts for a large proportion,and doubly-fed wind generator is the main type of wind power system.However,in the operation of the wind power system in the fault state,in order to ensure that the fan can not cause secondary damage in the system due to the fault state,based on this paper,the fault crossing strategy of the doubly-fed wind power generator is studied.In this paper,doubly-fed wind turbine is taken as the main research object.The basic structure and mathematical model of doubly-fed wind turbine are introduced in detail.The main analysis of the control method lies in the interaction between the converter and the motor,and the energy conversion between the wind turbine and the power grid can be realized through the voltage source converter.In order to realize the low-voltage crossing function,Crowbar circuit and Chopper circuit are introduced in detail,and the structure and parameter design of different Crowbar circuits are analyzed.By the method of using two ways of combination to realize low voltage across functions,in order to verify the effect of the low voltage across in electromagnetic transient simulation software PSCAD/EMTDC,build a complete model of doubly-fed wind power generation system,including mechanical parts and electrical parts,especially to the whole model of current transformer is analyzed,by setting the failure verify the effect of the low voltage across.Finally,in order to verify the feasibility of the combination circuit proposed by the theory,a doubly-fed wind power generation test system was built and the test analysis was carried out.The results showed that Crowbar circuit and Chopper circuit could achieve the function of low voltage crossing.