Network side power factor and harmonic suppression strategy of isolated AC-DC matrix converter

Abstract

The invention discloses a network side power factor and harmonic suppression strategy of an isolated AC-DC matrix converter. The method comprises the steps of firstly, introducing a virtual capacitor,and enabling virtual capacitor current generated under different loads to completely or partially compensate a phase difference between network side voltage and current caused by an input filter, sothat the IAMC works in a network side unit power factor state or a maximum achievable unit power factor (MAPF) state; and secondly, introducing a virtual resistor and connecting with a filter capacitor in parallel to form active damping control, and enabling the generated virtual damping current to effectively reduce harmonic waves of network side current under the condition of not increasing extra loss; and finally, compensating the virtual capacitance current and the virtual damping current to the reference current, and calculating a new modulation coefficient and a phase angle to realize acoordination control strategy of current space vector and phase shift control. According to the invention, the network side power factor of the converter can be controlled, the harmonic content of network side current is reduced, direct-current side ripple waves are suppressed, and it is guaranteed that the system has good input and output performance.

Description

technical field [0001] The invention relates to the field of high-frequency chain-matrix rectification, in particular to an isolated AC-DC matrix converter and a grid-side power factor control and harmonic suppression method. Background technique [0002] The PWM rectifier has the advantages of high degree of sinusoidal current on the grid side; controllable power factor on the grid side; energy can flow in both directions; fast dynamic response, etc., but the PWM rectifier cannot meet the voltage required by the equipment. If a power frequency transformer is introduced on the input side of the PWM rectifier, although the voltage required by the equipment can be met, the volume and weight of the system will increase, and the hardware cost will increase. Therefore, considering the introduction of a high-frequency transformer into the PWM rectifier, it can not only make the output voltage range of the converter larger, realize the electrical isolation of the input and output s...

AI Technical Summary

Problems solved by technology

At present, domestic and foreign scholars' research on the isolated AC-DC matrix converter is mainly on the modulation strategy and conventional closed-loop, but there are very few studies on the grid-side power factor control and harmonic suppression of the converter.

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