Method suitable for suppressing common mode electromagnetic interference in wind driven generator driving system

Abstract

The invention discloses a method suitable for suppressing common mode electromagnetic interference in a wind driven generator driving system. When a switching tube operates, a parasitic capacitor between the switching tube and a radiator generates a grounding interference leak current iL, and the grounding interference leak current iL flows to a ground terminal of the radiator; a voltage change signal du / dt generated during the operation of the switching tube is connected into an input terminal of a phase inverter; under the reverse action of the phase inverter, an output terminal of the phase inverter outputs a voltage change signal which is identical with the voltage change signal du / dt in amplitude and opposite to the voltage change signal du / dt in phase; the voltage change signal forms a compensating current -iL through an isolation transformer used for preventing an interference current from flowing back and a compensation capacitor CP, and the compensating current -iL enters the ground terminal of the radiator through a wire; the grounding interference leak current iL and the compensating current -iL are identical in amplitude and opposite in phase, so that the grounding interference leak current iL and the compensating current -iL offset each other, and common mode interference to conduction of the grounding interference leak current iL is suppressed. According to the method, on the basis of lowering the complexity and cost of the system, common mode interference in the driving system is effectively suppressed, and the stability and electromagnetic compatibility of the system are improved.

Description

technical field [0001] The invention relates to a method for suppressing common-mode interference, in particular to a method suitable for suppressing common-mode electromagnetic interference in a wind power generator driving system. Background technique [0002] In recent years, the PWM motor drive system has been widely used in China, and the research work on the influence of the inverter of the PWM motor drive system on the entire system has also been carried out. Among them, the research on the electromagnetic interference of the PWM motor drive system and the inverter has not It is still not perfect. Zhejiang University has conducted in-depth research on the generation mechanism of the conducted electromagnetic interference of the Buck circuit and its suppression measures, and proposed a dynamic node potential balance method, but this measure is not suitable for the electromagnetic interference of the drive system. inhibition. [0003] At present, all countries attach g...

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Problems solved by technology

[0005] Although the parasitic capacitance between the power tube and the radiator can be reduced by reducing the size of the radiator, and the impedance of the coupling loop can be increased, thereby reducing the conduction electromagnetic interference, but at the same time, the heat dissipation efficiency of the radiator is also reduced. It is beneficial to the normal operation of the whole system, so it is not feasible to reduce the conduction electromagnetic interference by reducing the size of the radiator

At present, most of the research work is on the problem of radiation interference, but the suppression of conducted electromagnetic interference through the principle of common-mode interference leakage current compensation has not received much attention.

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