Abstract : This paper details the principle and method of using the speed reduction and braking functions of a frequency converter to complete the temperature rise test of a wound-rotor asynchronous motor under intermittent duty. It discusses the energy-saving effect of using the speed reduction and braking functions of a frequency converter to replace a frequency-sensitive resistor, providing a more advanced test method for the "intermittent duty temperature rise" test of wound-rotor asynchronous motors. Keywords: Wound-rotor asynchronous motor, frequency converter, braking power supply, intermittent duty temperature rise test. 0 Introduction The technical specifications for the YzR series wound-rotor three-phase asynchronous motors for hoisting and metallurgy specify the temperature rise test under duty cycles S4, S5, and S7 as shown in Figure 1. The load motor should be a wound-rotor motor (with a capacity 2.5-3 times that of the motor under test). A frequency-sensitive resistor or reactance is connected in series with the rotor to operate it in a reverse braking state (slip s=1-2) to obtain constant torque characteristics. However, after connecting the frequency-sensitive resistor or reactance to the rotor of the load motor, the rotor's power factor cos α is 0.5-0.6. During the entire test, the losses generated by the braking torque will be entirely consumed by the frequency-sensitive resistor. Therefore, although this test method can produce constant torque characteristics, it generates significant electrical losses. Only wound-rotor motors with a capacity 2.5-3 times that of the motor under test can be selected as load motors, limiting the choice of load motors. Furthermore, connecting a load motor with a capacity 2.5-3 times that of the motor under test to the motor under test is a very cumbersome task, restricting the operability of temperature rise and load tests for wound-rotor three-phase asynchronous motors. To overcome these shortcomings, a method is proposed to use the speed reduction and braking functions of a frequency converter to complete the intermittent duty temperature rise test of a wound-rotor asynchronous motor. 1. Speed ​​Reduction and Braking Functions of Frequency Converters [b][align=center]For details, please click: A New Method for Temperature Rise Testing of Wound-Rotor Induction Motors under Intermittent Duty[/align][/b]