Experimental Research on Adjustable-speed Characteristics of Squirrel Cage Asynchronous Magnetic Coupling

In order to realize adjustable-speed application of Squirrel Cage Asynchronous Magnetic Coupling (SCAMC) in centrifugal load machinery according to the structure characteristics of SCAMC, the mathematical model of air gap magnetic flux density was established by the scalar magnetic potential method and two-dimensional field boundary conditions. The induced current model and electromagnetic torque equation of SCAMC were established by the method of current conversion of cage. According to the similarity theory of centrifugal load, the mechanical properties and adjustable-speed characteristics of SCAMC in total slip range were obtained, which directly reflects the relationship among electromagnetic torque, output speed and coupling length in the adjustable-speed process of SCAMC Furthermore, formulas of energy consumption and transmission efficiency were derived. Based on the above theory and technology, a 22kW SCAMC experimental prototype with a rated speed of 1450 rpm was designed and produced. Simulation verification and experiment measurement on its mechanical properties were performed The results show that the mechanical property curves of SCAMC experimental prototype in total coupling state are basically consistent with the theoretical calculation results, the errors are less than 3% The experimental prototype can realize stepless speed regulation in total slip range, and the experimental curves are uniform with the theoretical values. In the process of speed adjustment, the maximum loss point is 986 rpm, the transmission efficiency is 66% it is the biggest hot spot of SCAMC in the process of speed adjustment, which can provide a theoretical reference for the design of heat dissipation system.