High-power EMI (Electromagnetic Interference) filter

Abstract

The invention discloses a high-power EMI (Electromagnetic Interference) filter. The high-power EMI filter comprises three phase current output load ends and three phase current input ends, wherein a differential mode inductor L1, a common mode inductor L2 and a common mode inductor L3 are connected between each of the three phase current output load ends and each of the three phase current input ends in series in sequence; the differential mode inductor L1 is connected with a differential mode capacitor C1X and a common mode capacitor C1Y to form a first-order filter; the common mode inductor L2 is connected with a differential mode capacitor C2X and a common mode capacitor C2Y to form a second-order filter; the common mode inductor L3 is connected with a differential mode capacitor C3X and a common mode capacitor C3Y to form a third-order filter; the differential mode capacitors C1X, C2X and C3X are bridged between a phase line and a neutral line; and the common mode capacitors C1Y, C2Y and C3Y are bridged between the neutral line and a ground line. According to the high-power EMI filter, the performance and safety of the filter under high current can be guaranteed, and EMC (Electromagnetic Compatibility) filtering in high-current and high-power systems can be met.

Description

technical field [0001] The invention relates to a filter, in particular to a high-power EMI filter. Background technique [0002] With the extensive use of nonlinear equipment based on modern power electronic devices, such as switching power supplies, frequency converters, etc., a large number of high-frequency components are injected into the power grid, polluting the power grid, and interfering with the normal operation of adjacent equipment. Especially for the converters used in solar energy and wind energy in the new energy, if the EMI problem is not dealt with during the grid connection process, there will be a large number of high-frequency components that will cause equipment failure and damage. [0003] The EMI filter is usually a low-pass filter circuit composed of a series reactor and a parallel capacitor. Its function is to allow the frequency signal to enter the device when the device is working normally, and has a greater hindrance to the high-frequency interfer...

AI Technical Summary

Problems solved by technology

Because the output current and voltage of inverters such as wind energy and solar energy contain high-frequency components, and the power of inverters is constantly increasing, the existing filters cannot well meet the needs of photovoltaics, wind power generation, rail transit, and charging piles. , and the filtering requirements of high-power industrial drive field, therefore, it is necessary to provide high-power EMI filter

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