Induction Motor Drive System

Abstract

The invention discloses an induction motor driving system which comprises the components of a two-phase induction motor, a power filter circuit, an H-bridge power driving circuit and a microcontroller unit MCU. The power filter circuit is used for filtering a harmonic component on a DC power supply and generating a power supply middle-point voltage required for driving. The microcontroller unit MCU is used for generating a switching control signal which is required for operation of the H-bridge power driving circuit. The H-bridge power driving circuit is used for generating a driving current and transmitting to the two-phase induction motor. The two-phase induction motor is used for receiving the driving current which is generated by the H-bridge power driving circuit. The induction motor driving system has advantages of remarkably reducing loss, reducing cost, improving reliability and motor efficiency, expanding speed regulation range and reducing noise.

Description

Technical field [0001] The invention relates to the technical field of driving of an induction motor, in particular to an induction motor driving system. Background technique [0002] When designing a single-phase induction motor, the air gap magnetic field of the motor can only be designed to be circular at a certain speed; for example, if the starting characteristics of the motor are particularly concerned, the air gap magnetic field of the motor in the starting state can be designed as Circular, but this will cause the magnetic field to be elliptical during operation. If the motor’s operating characteristics are emphasized, the air gap magnetic field of the motor at rated speed can be designed to be circular, but this will make the magnetic field of the motor in the starting state Oval, the elliptical magnetic field will cause additional losses and noise in the motor, which are undesirable in motor applications, which also limits the reasons for single-phase induction motors, ...

AI Technical Summary

Problems solved by technology

[0002] When designing a single-phase induction motor, the air-gap magnetic field of the motor can only be designed to be circular at a certain speed; for example, if special attention is paid to the starting characteristics of the motor, the air-gap magnetic field of the motor in the starting state can be designed as Circular, but this will cause the magnetic field to be elliptical during operation. If we focus on the operating characteristics of the motor, the air gap magnetic field of the motor at rated speed can be designed to be circular, but this will make the magnetic field of the motor in the starting state It is elliptical, and the elliptical magnetic field will cause additional loss and noise of the motor, which are undesirable in motor applications, which also limits the reasons for single-phase induction motors, such as occasions that require speed regulation

[0003] For multi-phase induction motors including two-phase induction motors, when the corresponding multi-phase drive voltage is symmetrical, the air gap magnetic field of the motor is circular at all speeds, so that the motor has high efficiency, quietness and high power density. Features, if frequency control is used, these multi-phase induction motors can be adjusted in a wide range, and the efficiency is high; in order to realize the drive of two-phase induction motors, or other even-numbered M-phase induction motors, usually need 4M power semiconductor tubes are used to form a multi-phase bridge. If the number of phases is odd, 2M power semiconductor tubes are needed to form a multi-phase bridge. This requires multiple control signals to carry out linkage chopping control on these power semiconductor tubes, so that Realize multi-phase symmetrical driving current, which makes the structure of the driving circuit complex, the calculation of the control signal difficult, the reliability of the starting system is poor, and the cost of the driving system is also high, which obviously limits the application of motors such as two-phase induction motors

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