A system and method for suppressing high-frequency vibration of a low-voltage high-power multi-phase variable-frequency motor

Abstract

The invention relates to a system and method for retraining high-frequency vibration of a low-pressure large-power multi-phase variable frequency motor. Due to the fact that a variable frequency power supply output impulse sequence is optimized, by means of a magnetic field coupling relationship in the motor, electromagnetic exciting force causing the high-frequency vibration is reduced, and the purpose of retraining the high-frequency vibration of the motor is achieved. The method for retraining the high-frequency vibration of the low-pressure large-power multi-phase variable frequency motor can effectively reduce the high-frequency vibration of the motor, reduces noise, and is suitable for the fields of large-power industrial electric transmission, rail transit, ship electric propulsion and the like.

Description

technical field [0001] The invention relates to a system and method for suppressing high-frequency vibration, in particular to a system and method for suppressing high-frequency vibration of a low-voltage high-power multi-phase frequency conversion motor. Background technique [0002] Most modern AC drive systems are powered by PWM (Pulse Width Modulation) voltage source inverters. The output of the inverter is a series of equal-amplitude pulse sequences, which include not only the required fundamental wave components, but also a series of sideband harmonic components of the switching frequency and its multiples. The voltage is applied to the winding end of the motor to generate a high-frequency electromagnetic excitation force, which in turn excites the high-frequency vibration of the motor. For the high-power AC electric transmission system, due to the large equipment capacity, the problem of high-frequency vibration is prominent, and the high-frequency vibration is trans...

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Problems solved by technology

For the high-power AC electric drive system, due to the large equipment capacity, the problem of high-frequency vibration is prominent, and the high-frequency vibration is transmitted through the motor structure to form high-frequency noise, which brings serious noise pollution

[0003] For the treatment of high-frequency vibration and noise, there are mainly methods such as increasing the PWM switching frequency, installing an output filter, and using random modulation. However, the application of these methods in the field of low-voltage and high-power AC drives is limited, mainly reflected in: The switching frequency can effectively suppress the high-frequency current harmonic components output by the PWM inverter, thereby reducing high-frequency vibration and noise, but for low-voltage high-power AC drive systems, considering device characteristics, device efficiency, weight and equipment reliability, the switching frequency Due to restrictions, this method cannot be used to suppress high-frequency vibration and noise; b) An output filter is installed at the output of the inverter, which can filter out high-order harmonics in the output voltage sequence, but the volume and weight of the filter are considerable. At the same time, the filter is also a source of vibration and noise. For low-voltage and high-power transmission applications, the application of this method is greatly limited; c) The random PWM modulation method is to disperse the locally concentrated high-frequency vibration and noise features into features within a certain frequency spectrum, but because there is no significant change in vibration energy, actual research shows that there is no significant change in the total level of high-frequency vibration acceleration

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