Abstract
The article considers the synthesis of a direct torque control system in a two-phase asynchronous electric motor with an external rotor. In low-power motors, the placement of a three-phase winding can be difficult. In this case, a two-phase stator winding is used. Control systems without a speed feedback sensor for mechanisms that do not require increased control accuracy, or even open-speed rotations are also of great interest. The latter are used in traction electric drives of mobile installations, for example, in electric bicycles and scooters. The well-known electric drive system for three-phase motors is taken as a basis. The article shows the principle of dividing the spatial positions of the voltage vector into 8 positions depending on the number of transistors included in a two-phase autonomous inverter. An algorithm for generating control signals by power keys in the tabular form is synthesized depending on the combinations of relay regulators states in the flow coupling of the stator and the electromagnetic moment, as well as taking into account the sector number of the current flow coupling vector position. Each regulator has three fixed states with transitions along hysteresis loops. To test the algorithm operability, a simulation model of a traction electric drive in the MatLab Simulink system has been developed. The control system structure and the principle of control signals tabular generation in the power unit are shown. To limit the total current of the stator, an additional relay current regulator has been introduced, which sets zero voltage vectors when the current amplitude reaches the set values. To test the control system, an experimental sample of an electric drive with a control system based on an STM32F407 microcontroller with a traction two-phase three-pole asynchronous motor with a power of 500 watts was designed and manufactured. The graphs of experimental studies proving the proposed technical solutions operability are presented.
Keywords
Direct torque control; two-phase asynchronous electric motor; motor with external rotor; autonomous inverter; stator flow coupling; simulation model.
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Grekov Е.L., Bezgin A.S. Direct Torque Control by Two-Phase Asynchronous Electric Motor. Elektrotekhnicheskie sistemy i kompleksy [Electrotechnical Systems and Complexes], 2022, no. 4(57), pp. 54-59. (In Russian). https://doi.org/10.18503/2311-8318-2022-4(57)-54-59