Research On A Motor Loading System Based On Electromagnetic Torque Of Generators

With the development of electric motors in the field of military, electric power, electromechanical engineering etc., it is significant to study performance index of the motor and imitate the motor’s working conditions. Therefore, the motor loading system, which is safe, reliable and flexible, is pressingly needed.Based on working principles and loading methods of the current motor loading systems, this paper puts forward a real-time loading method, which loads the motor by controlling the electromagnetic torque of the generator. Considering the electromagnetic torque of excited generators is easy to control, excited generators are chosen to be research object. After analyzing the working principle and characteristics of three kinds of excited generators, that is, the excited DC generator, the excited AC asynchronous generator and the excited AC synchronous generator, the excited AC synchronous generator is chosen to load the motor.The rotor of the generator and the rotor of the motor are connected coaxially and rigidly at the rate of 1:1. The real loading system platform consists of a host computer and a slave computer. The host computer is designed with C++ language. Its function is to send instructions to the slave computer, receive feedbacks from the slave computer and plot loading curves. The slave computer takes ATmega128 as controlling processor. Its function is to execute instructions from the host computer to control the loading process, collect real-time loading data and send back to the host computer.Through experiments on the loading system, the aim of loading the motor with a real-time constant torque is achieved by making a constant electromagnetic torque of the generator; the aim of loading the motor with a real-time changing torque is achieved by making the electromagnetic torque of the generator vary as sinusoidal or sawtooth wave. Deviation between actual loading torque and theoretical loading torque is around 6.7%. Through long-term experiments, the loading system proves to be stable, sustainable and flexible. Besides, it should have a broad market prospect and application value because of low cost.