Novel three-phase PFC (power factor correction) rectifier

Abstract

The invention provides a novel three-phase PFC (power factor correction) rectifier. The novel three-phase PFC rectifier is characterized in that three-phase input currents are respectively rectified by a full-wave rectifier circuit in a full-bridge mode after input voltages of three-phase alternating-current input ends are transmitted through respective boost inductors, switch circuits are respectively arranged between the boost inductors and middle points M of output voltages of output ends in a connected manner, voltages of output capacitors C1 and C2 of the output ends are boosted and stabilized by the switch circuits by means of PWM (Pulse width modulation) required by corresponding phases, and accordingly constant voltages V<o> can be outputted even under the condition of variation of loads R of the output ends in design ranges; magnet excitation and demagnetization circuits which comprise capacitors are formed between the middle points M of the output voltages of the output ends and nodes of the input voltages of the three-phase alternating-current input ends, so that the boost inductors can be decoupled under working conditions and can work in critical current modes. The novel three-phase PFC rectifier has the advantages that the novel three-phase PFC rectifier can work in the critical current modes (CRM) and also can work in CCM (continuous current mode) or DCM (discontinuous current mode) states according to requirements, and accordingly requirements on high power density and high efficiency can be met.

Description

technical field [0001] The invention relates to a novel three-phase PFC rectifier. Background technique [0002] Due to the problems of excitation and demagnetization, the traditional VIENNA rectifier can effectively work in the continuous current mode (CCM Continuous Current Mode). The characteristics of this type of operation mode cause the reverse recovery of the rectifier diode to increase the loss. The rectifier diode can be changed to The latest technology of silicon carbide (SiC) can solve the problem of reverse recovery, but the economic cost will be greatly increased, and the forward voltage (VfForward Voltage) of SiC is larger than that of ordinary diodes, and the efficiency will not be significantly improved. If the discontinuous current mode (DCM Discontinuous Current Mode) is used, the problem of reverse recovery of the diode can be solved, but it will lead to a large peak current, making the stress standard of the power device more stringent, and the utilizatio...

AI Technical Summary

Problems solved by technology

[0041] The present invention provides a novel three-phase PFC rectifier, which solves the problem that the traditional VIENNA rectifier in the prior art can only work in the DCM or CCM state due to its own decoupling mode, that is, its operating frequency must be fixed.

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