Harmonic-current injection type three-phase power factor correction circuit with high voltage-reduction transformation ratio

Abstract

The invention relates to a harmonic-current injection type three-phase power factor correction circuit with high voltage-reduction transformation ratio. A triple-switch harmonic-current injection network is adopted for compensating a part with a dead zone of input phase current in a power frequency rectification process so as to realize three-phase current sine control. A risk of input-voltage short circuit in switching in the harmonic-current injection network does not exist; the current conversion among the injection branch bridge arms can realize no-dead-zone smooth transition so as to further reduce input current distortion; a switch inductance network is introduced to form a structure of series-wound charge and shunt-wound discharge; and the voltage-reduction output with high transformation ratio is realized by combining the switch control of the harmonic-current injection network. According to the three-phase power factor correction circuit, complicated vector control is not required; the sinusoidal three-phase input current and high voltage-reduction transformation ratio can be realized by only adopting a DC/DC PWM control technology; the three-phase power factor correction circuit is convenient to control and easy to implement; and the working range of duty ratio is expanded, the conduction loss can be reduced, and current-sharing control in multi-machine parallel operation can be realized easily.

Description

technical field [0001] The invention relates to a three-phase power factor correction circuit of a large step-down ratio harmonic current injection type. Background technique [0002] Uncontrollable rectification or phase-controlled rectification in power electronic devices will generate a large amount of harmonic current on the grid side, resulting in low utilization of the power system, large losses, affecting the normal operation of electrical equipment and even endangering the stable operation of the entire power grid. Governance has been paid more and more attention by the academic circles and governments of various countries, and many harmonic limit standards have been issued to regulate the harmonic content of electrical equipment. Such as IEC61000-3-2, GB17625.1 and other standards clearly stipulate the harmonic current limit of electronic equipment, and only electronic equipment that meets the requirements of the specification is allowed to be listed. [0003] High...

AI Technical Summary

Problems solved by technology

[0003] High-power electrical equipment with a power of more than 5 kW usually uses three-phase power supply, which generates large harmonic pollution, but power factor correction (PFC) technology has not been widely used, mainly due to the insufficient development of three-phase PFC technology Mature, complex system structure and control in practical application, difficult to realize

In recent years, a type of harmonic current injection type three-phase PFC circuit has emerged. For example, the SWISS rectifier is one of the step-down structures, but the harmonic current injection network is prone to the risk of phase-to-phase short circuit, and at low voltage output, the duty cycle If the ratio is too small, it is not conducive to the optimization of system efficiency

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