Simple on-line monitoring technology for magnetic performance attenuation of permanent-magnet synchronous motor

Abstract

The invention discloses a simple on-line monitoring technology for magnetic performance attenuation of a permanent-magnet synchronous motor. A current of a motor stator winding is acquired by a current transformer arranged at an output end of a frequency converter, a core controller of the frequency converter is used for performing coordinate conversion by employing a vector control algorithm so that a motor stator current vector is decomposed to an excitation component Id and a torque component Iq, and the stator current can be all used for generating an electromagnetic torque by employing acontrol mode of Id equal to 0 according to an electromagnetic torque formula of the permanent-magnet synchronous motor. In the mode, the motor is controlled to gradually reach rated frequency by the frequency converter, at the moment, a counter potential induced by the motor stator can be equivalent to an output voltage of the frequency converter, the magnetic flux in a magnetic path is obtained according to a relation between the counter potential and a magnetic link, so that the magnetic performance attenuation condition of a permanent magnet of the permanent-magnet synchronous motor can bejudged; the core controller is used for transferring a voltage value obtained by calculation and the magnetic performance attenuation percent of the permanent magnet to an upper computer for displaying via series communication, and on-line monitoring is achieved; the technology is simple to operate and easy to implement and can be applicable to an industrial and automatic side with general requirement; and the permanent-magnet synchronous motor has the beneficial effects of simple structure and high practicability.

Description

technical field [0001] The invention relates to the field of industrial automation, in particular to a simple on-line monitoring technology for magnetic performance attenuation of a permanent magnet synchronous motor. Background technique [0002] At present, permanent magnet synchronous motors are widely used in the field of industrial automation that requires motor driving because of their excellent performance. Compared with DC motors, it has no commutator and brushes of DC motors, and the rotor uses permanent magnets, so the structure is simple, easy to maintain, and the number of fault points is reduced; compared with asynchronous motors, it does not require reactive excitation current, so the efficiency High, high power factor, large moment of inertia, reduced stator current and stator resistance loss, and measurable rotor parameters, good control performance. The frequency converter for permanent magnet synchronous motor control adopts an advanced vector control sche...

AI Technical Summary

Problems solved by technology

Traditional flux linkage detection methods include Kalman filter, demagnetization state prediction and observation methods, etc. These methods have the disadvantages of complex algorithms and unsuitable implementation. For generally less demanding working conditions, simple online monitoring technology can be used to achieve permanent flux linkage detection. Real-time monitoring of magnetic properties of magnets

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