Method and device for eliminating mutual inductance coupling electromagnetic interference

Abstract

The invention discloses a method and device for eliminating mutual inductance coupling electromagnetic interference; the method of the invention comprises the steps that: after a current signal on the power line of a strong current interference source system is detected and converted into a voltage signal, amplitude amplification is carried out to the normal phase or the reversed phase of the measuring conversion voltage signal and the voltage signal is converted into an output current signal, the value of which is not affected by the load; then the output current signal is converted into an offsetting signal which is equal to an interfering signal in amplitude and contrary to the interfering signal in phase; and the offsetting signal is injected into the loop of a weak current device to offset the interfering voltage inducted by the strong current interference source system to the loop of the weak current device by inductance coupling. The method of the invention dexterously brings in a voltage / current switching circuit, thereby overcoming the influence of the loop impedance of the weak current device on the offsetting effects and enlarging the application scope of the mutual inductance coupling offsetting method. The method and the device of the invention has low power consumption and cost, overcomes the defect that EMI filtering can not remove the interfering signals with the same frequency; compared with a shielding method, hardware devices required by the invention has smaller volume and lighter weight, thus not increasing the difficulty of system layout.

Description

technical field [0001] The invention belongs to the field of electromagnetic interference suppression, in particular to a method and device for eliminating mutual induction coupling electromagnetic interference, and is especially suitable for eliminating and suppressing mutual induction coupling electromagnetic interference at the system level. Background technique [0002] In independent systems such as modern ships and aircrafts, the power lines of strong current equipment and the power lines or signal lines of weak current equipment are often placed in parallel, and the distance is very close. Therefore, the high-frequency harmonic current generated by power electronic equipment on the strong line will generate interference noise voltage in the circuit of the weak current equipment through mutual inductance coupling, affecting the normal operation of the weak current equipment, and even causing the weak current equipment to malfunction, causing serious consequences. In or...

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Problems solved by technology

However, the main object of these studies is a single inverter or low-power switching power supply, and the research content is limited to circuit-level conducted electromagnetic interference, and the cancellation method is applied to suppress system-level conducted electromagnetic interference, especially to eliminate and suppress mutual inductance Coupled electromagnetic interference, there is no literature report at home and abroad

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