Abstract : This paper introduces the principle of double-fed motor speed regulation and constructs a double-fed speed regulation system model using Matlab software. The rotor winding is powered by an AC-AC frequency converter. The paper points out the mismatch problem between the asynchronous motor model in the Matlab simulation library and the frequency converter and proposes corresponding solutions, achieving good results. A simulation of an example was performed using this model, and the simulation results closely match the actual operation, verifying the model 's correctness. This system model has certain reference value for studying such double-fed variable frequency speed regulation systems. Keywords: Frequency converter connection matching, double-fed speed regulation Keywords: cycloconverter model matching, double-fed speed regulation 1. Composition of a Doubly-Fed Speed ​​Regulation System For wound-rotor asynchronous motors, a doubly-fed speed regulation system is formed when the stator is connected to an industrial power supply with a fixed frequency (50Hz) and the rotor is connected to a frequency converter power supply with adjustable frequency, amplitude, and phase. A rotor frequency detector is installed on the motor shaft to measure the slip frequency. Using this signal and vector control technology, the amplitude, frequency, and phase of the output voltage (current) of the frequency converter power supply can be controlled, making the speed regulation performance of the asynchronous motor almost comparable to that of a DC motor. 2. Theoretical Basis of Vector Control To achieve good speed regulation performance, advanced vector control technology is adopted for the doubly-fed motor. The essence of vector control is to construct a DC motor model within an AC motor and regulate its speed using DC motor speed regulation methods. However, in order to control the actual controllable quantity, it is necessary to transform it back to the original coordinate system. The specific implementation method is to first determine the direction of the stator flux linkage, and then use this direction as the dc axis of the synchronous rotating coordinate system, leading it by 90 degrees. The direction of the flux linkage is the gc axis, thus forming a dc-gc synchronous rotating coordinate system. After transforming the rotor current from three-phase to two-phase, and then transforming it back to the synchronous coordinate system, the rotor current is coupled into a pair of torque and excitation components. The former is located on the gc axis, and the electromagnetic torque is only related to this value; the latter is located on the gc axis, which plays a role in excitation and can improve the power factor on the stator side. [b][align=center]For more details, please click: Research on Doubly Fed Speed ​​Control System Based on Matlab[/align][/b]