Active filtering apparatus capable of eliminating high frequency switch EMI and control method thereof

Abstract

The invention provides a control method of an active filtering apparatus capable of eliminating a high frequency switch EMI. An active filter general control circuit, an integrated-type EMI filtering module and a first filtering branch control system are included. Active filter general control mainly aims at absorbing 2-50 times of a harmonic current. The integrated-type EMI filtering module mainly aims at a switch frequency harmonic current generated by an active filter and comprises a high-frequency absorption filtering module, a switch frequency harmonic current filtering module and a surge protection circuit. High-frequency and switch-frequency harmonic currents injected by a high frequency switch tube to a power distribution system can be fully filtered, and high frequency interference problems in a system and harms which are brought by a high frequency harmonic wave to electrical equipment and especially a precision load are reduced.

Description

technical field [0001] The invention relates to power electronic device technology, relates to the field of power electronic device technology for filtering high-frequency switch tube (IGBT) switching frequency harmonic currents, and in particular to an active filter device and a control method for eliminating high-frequency switch EMI. Background technique [0002] The harmonic content in the distribution network system is an important index to measure the quality of power energy, and it is also an important governance object for promoting clean energy and purifying the power grid in recent years. When the sine wave voltage is applied to the nonlinear load circuit, the current becomes a nonlinear change, causing a non-sinusoidal waveform that is not synchronized with the voltage. The non-sinusoidal current produces a nonlinear voltage drop on the grid system impedance, causing the system voltage The waveform also becomes non-sinusoidal. According to the Fourier series, any...

AI Technical Summary

Problems solved by technology

"However, the above-mentioned invention still has defects, and it is impossible to perform surge protection for the system and filter the switching frequency harmonic current of the active filter, and perform low-order harmonic filtering and high-frequency and switching frequency harmonic current filtering.

The above-mentioned invention is only aimed at the control system algorithm, not the invention of filtering the high-frequency harmonic current and switching frequency harmonic current for peripheral hardware parameter configuration, reducing the high-order harmonic and switching frequency sub-harmonic current injected into the power grid

The above invention cannot effectively filter out high-order harmonics and switching frequency sub-harmonics, and the filter branch does not adopt closed-loop control, which is easy to form resonance amplification harmonics with system impedance

Images