Multiphase induction motor electronic pole-changing transmission device

Abstract

The invention discloses a multiphase induction motor electronic pole-changing transmission device which comprises a multiphase induction motor, a multiphase inverter, an inversion driving unit, a detection unit and a pole-changing control unit, wherein the phase number n of the multiphase induction motor is not less than 5, a stator winding is formed by n windings the axial lines of which are arranged at intervals of 2Phi / n electrical degree in sequence, each phase winding contains at least two kinds of space harmonic components simultaneously, and a motor rotor adopts a squirrel-cage structure; the pole-changing control unit determines what kind of pole number and corresponding control freedom degree the motor adopts according to an input rotation speed signal, electric currents with different phase differences are respectively introduced to the multiphase induction motor by the multiphase inverter so as to generate rotating magnetic fields with different pole pairs in an air gap, namely, different freedom degrees can be switched so as to realize pole changing. The multiphase induction motor electronic pole-changing transmission device adopts the multiphase induction motor and a set of multiphase inverter, realizes wide-range pole-changing speed control of the transmission system, has simple winding structure and high reliability and is easy to realize large-power transmission.

Description

technical field [0001] The invention relates to a multi-phase induction motor electronic pole-changing transmission device, which is especially suitable for a high-power and wide-range speed regulation system. Background technique [0002] In many applications, such as servo systems for machine tools, aircraft drives, and flywheel energy storage systems, it is urgently required that the transmission system not only provide large torque at low speeds, but also have a wide operating range of constant power speed regulation. Traditional induction motors The constituted AC drive system works in constant torque mode below the rated frequency, and in constant power mode above the rated frequency. In the constant power mode, the voltage at the motor terminal increases slowly with the increase of the frequency. When the voltage reaches the maximum voltage that the frequency converter can provide in the case of power supply by the frequency converter, the transmission system cannot c...

AI Technical Summary

Problems solved by technology

The commonly used solution is to connect the transmission system and the load through a mechanical gearbox, and change the speed ratio of the gearbox to meet the requirements, but this method is complicated in equipment, increased in size and reduced in control accuracy; it is also possible to simply use a larger power motor And large-capacity inverter, but the size of the motor and the capacity of the power device will increase, which will cause a lot of waste in economy and energy

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