Study On Current And Electromagnetic Force Of Damping Windings In Dynamic Conversion Process Of Generator/Motor

Pumped storage power station plays an important role in regulating grid power and ensuring safe and stable operation of power grid.Generator/motor is one of the core equipment of power station.Since the motor needs to be converted frequently in stopping,phase modulation,power generation and electric operation conditions,Starting and stopping frequently,two-way rotation characteristics.In the process of dynamic conversion,the electrical parameters will change.In order to clarify the restraint mechanism of the main structural components during dynamic conversion,it is necessary to systematically study the damping winding current and electromagnetic force in dynamic conversion process,and to optimize the generator/motor design and safe and stable operation to provide a theoretical reference.Based on the analysis of a large number of literatures at home and abroad,the research status of current and electromagnetic force of damping winding is expounded,the research methods of existing achievements are pointed out,and the research contents of this paper are established.In this paper,a generator of a pumped storage power station is taken as the research object.The Maxwell equation of the two-dimensional time-varying electromagnetic field is given.On the basis of this,the expressions of damping winding current and Lorentz force are deduced.Variety of operating conditions under the analysis of motor parameters.First of all,the finite element model is established to analyze the damping winding current and harmonics under no-load operation,damping the wall flux density.Then,the motor parameters law under different load torques and different excitation currents are simulated,such as the power factor angle,power angle,stator armature current,reactive power and so on,as well as the analysis of air gap flux density,Damping bar current,damping wall flux density,damping Lorentz force.Finally,the Lorentz force of the damping winding is simulated by different load conversion process.It is concluded that the rated load transition to 0.2 time load,0.4 times load,0.6 times load,0.8 times load process,the change of the damping bar lorentz force and the law.The damping current and Lorentz force under different conditions in this paper can provide reference for the follow-up damping winding structure optimization,damping winding loss and other issues.