A matrix converter with source damping filter unit and its control method

Abstract

The invention discloses a matrix converter with an active damping filter unit, which includes an input power supply, an LC input filter unit, a switch matrix and a microprocessing unit, and the current provided by the input power supply is input to the load through the LC input filter unit and the switch matrix in sequence , wherein the microprocessing unit controls the LC filter input current waveform by controlling the resonance damping of the LC filter to obtain the expected output voltage, distributes the pulses of each switch tube in the switch matrix according to the expected output voltage, and controls the switch The working status of each switch tube in the matrix. The present invention also provides a control method for the above-mentioned matrix converter containing the active damping filter unit. The invention improves the dynamic characteristics, and can reduce the harmonic content of the power supply current, so that the power supply side is always close to the unit power factor, and improves the efficiency of the matrix converter. At the same time, the resonance of the LC filter is effectively suppressed, the total harmonic distortion rate of the power supply current is reduced, and the influence of the matrix converter on the power grid is weakened.

Description

technical field [0001] The invention relates to a matrix converter, in particular to a matrix converter with an active damping filter unit and a control method thereof. Background technique [0002] Adding an LC filter on the input side of the matrix converter is mainly to meet the requirements of electromagnetic compatibility, to prevent the input of the matrix converter from entering the power grid due to glitches caused by high-frequency switching of switching devices; to filter out high-frequency voltage components in the power grid , so as not to affect the output quality of the matrix converter. However, the LC filter is a second-order underdamped system. When the system contains harmonics close to the resonant frequency of the LC filter, the input current will be seriously disturbed, and even the system cannot work normally. When analyzing the input filter of the matrix converter, under the premise of three-phase input voltage balance and three-phase load balance, th...

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Problems solved by technology

However, these two methods can only improve the dynamic characteristics and suppress resonance, but cannot guarantee the unity power factor of the input side

There are also literatures that use PID controller instead of PI controller to increase the damping of the system. This method suppresses resonance and ensures unity power factor at the same time, but it will increase high-frequency noise.

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