Electromagnetic Loss Calculation And Flow Thermal Coupling Study Of High Temperature Gas Cooled Reactor Helium Driving Motor

In recent years,with the rapid development of power electronics technology,frequency motors powered by inverters have been widely used in various fields for their flexibility and low energy consumption.When the inverter is powered,its supply voltage contains abundant high-order harmonics,which not only increases the copper loss of the stator windings and rotor bars due to skin effects,but also generates additional iron loss in the stator core,reducing the efficiency and power factor of the motor.The high temperature gas cooled reactor helium driving motor(hereinafter referred to as the driving motor)studied in this paper provides cooling cycle power for high temperature gas-cooled nuclear reactors and it is required no faults for at least 40 years.Therefore,it is of great significance to study the influence of harmonics on the electromagnetic performance and temperature rise of the motor when the inverter is powered.The driving motor is a two-pole vertical asynchronous motor.According to the circumferential symmetry characteristics of the motor and the given parameters,the 1/2 plane model of the motor is established.Reasonable assumptions and boundary conditions are given.The finite element method is used to divide and calculate the electromagnetic field of the motor under different operating states.The electromagnetic field of the motor running under rated load is calculated and compared with the two different power supply modes of sinusoidal power supply and inverter power supply.The current,copper loss and iron loss of the motor under two kinds of power supply modes are obtained.The difference between waveform and quantity are compared and the influence of harmonics on the running performance of the motor is specified which is quantitatively calculated.For the complexity of the heating and cooling of the driving motor and the characteristics of the motor under high temperature and pressure conditions,based on the analysis of the research status of the motor fluid field and temperature field by domestic and foreign scholars,according to the structural characteristics of the motor,1/24 model of the motor is established.The distribution of the fluid field in the motor is calculated and analyzed,and the general law of the flow of helium in the motor is concluded.The finite volume method is used to calculate the temperature field of the motor under the two power supply modes under the rated working condition and the comparative analysis is made.The law of the influence of the temperature rise of each part on the harmonics is obtained.Through the quantitative calculation of the temperature rise under the two power supply modes,the theoretical basis for the cooling structure design of the driving motor and the temperature field calculation of the same type of motor is provided.