Speed Regulation Mechanism And Heat Dissipation Structure Design Of Winding Type Magnetic Coupler

The electricity consumption of centrifugal load machines such as draught fans and pumps accounts for more than 30%of the total electricity consumption in China.Therefore,the research on speed regulation and energy saving of centrifugal load machines possesses great theoretical significance and application value.At present,there are mainly three kinds of speed regulation methods:pole-change,frequency-change and variable slip.Among them,variable slip speed regulation with magnetic coupler has the advantages of high air gap magnetic density and simple mechanical structure,which has attracted extensive attention,especially researchers and enterprises.There are two main problems in the current magnetocoupler speed regulation:firstly,because it is slip speed regulation,that is,the greater the slip,the bigger the calorific value,so the high-power magnetocoupler heat is difficult to dissipate under air-cooled conditions;secondly,the existing magnetocoupler speed regulation mechanism is generally spline pair,which not only has low speed regulation accuracy,but also is very easy to wear and tear when the speed regulation is frequent,resulting in the speed regulation mechanism can not work.In order to solve the above problems,the Winding type Magnetic Coupler(WMC)is studied in depth in this paper.Because WMC uses external series resistance to adjust speed,the induced current inside the WMC can be drawn to the external resistance box to realize high power and large slip speed regulation under air cooling conditions.In addition,the speed regulation mode of WMC is static electric speed regulation,which also solves the problems of mechanical wear and tear of the existing magnetic coupling device.In this paper,the research status of magnetic coupling at home and abroad is summarized,and the working characteristics of WMC are analyzed and elaborated.Because the magnetic potential of each pole of radial structure is twice that of tangential structure,the magnetic circuit structure of permanent magnet external rotor with radial distribution is adopted.The magnetic field distribution of the structure is analyzed by ANSYS Electronic,and the induced potential and induced potential of the rotor in WMC conductor under rated state are established.Mathematical model of current and output torque.The energy-saving principle of WMC speed regulation is analyzed in depth,and the relationship model between outer series resistance and output speed and torque of WMC inner rotor is established based on it.In view of the starting difficulty caused by small starting torque and large starting current when starting WMC,the inherent starting characteristics of WMC are changed by connecting outer series resistance,and the relationship model between outer series resistance and output speed and torque of WMC is established.The optimum resistance value of WMC at start-up is given.SolidWorks software is used to build the three-dimensional model of WMC without heat dissipation structure,and Flow Simulation is used to simulate the temperature field of the three-dimensional model.The results show that the temperature rise of the permanent magnet on the outer permanent magnet rotor and the rotor winding inside the conductor is higher,butdue to the small excess,the required heat dissipation can be achieved by installing fans and designing a reasonable heat dissipation structure.Three kinds of fans and their types are analyzed.According to the requirements of WMC speed regulation,a wind path structure suitable for WMC heat dissipation is designed and an axial-flow fan is installed.The initial state,intermediate state,outflow state and entering spoke channel state of the fluid entering the axial-flow fan are analyzed in detail,and the velocity and static pressure nephograms of the four sections are given.It is verified to combine the velocity vector and flow trace in WMC fluid-solid coupling field,the feasibility of the designed wind path structure.