Partial active electrical source power factor correction circuit

Abstract

The present invention provides a partial active power supply power factor correction circuit. On the basis of the prior art, the partial active power supply power factor correction circuit is provided with a branch between the anode of the isolation diode and the negative pole of the bridge rectifier circuit, including one end and The anode of the isolation diode is connected to the second capacitor, the other end of the second capacitor is connected to the cathode of the second diode, the anode of the second diode is connected to the cathode of the third diode, and the anode of the third diode is connected to the third capacitor One end, the other end of the third capacitor is connected to the negative pole of the DC output terminal of the bridge rectifier circuit; the common end connected to the second diode anode and the third diode cathode is connected to the AC input end of the bridge rectifier circuit not connected to The other end of the inductance is connected; a controlled switch is connected between the cathode of the second diode and the anode of the third diode; the controlled switch is controlled to close when the DC side voltage of the bridge rectifier circuit is lower than the critical voltage, When the DC side voltage of the bridge rectifier circuit is higher than the critical voltage, it is controlled to shut down.

Description

technical field [0001] The invention relates to power supply technology, in particular to a partial active power supply power factor correction circuit. Background technique [0002] In the power grid, various loads, especially non-linear loads, have a major impact on the quality of power grid power supply. For example, the power supply of many electrical appliances needs to convert the alternating current of the grid into direct current, and the pulsating current generated during the rectification process contains a large number of current harmonic components. These current harmonic components flow back into the grid, which will cause harmonic "pollution" to the grid. When the current flows through the line impedance, it will cause a harmonic voltage drop and distort the sine wave grid voltage. In addition, the generated harmonics also cause the power factor of the grid current to decrease, increase the loss of the distribution system wires and transformers; and increase t...

AI Technical Summary

Problems solved by technology

The problem of this kind of power factor correction circuit is: the switching frequency of the internal switching tube is very high (generally above 20K), so it will generate considerable electromagnetic interference during operation, which will make the interference voltage and interference power of the system exceed the standard. In order to suppress the PFC The interference brought by itself generally requires multi-stage filtering, which will inevitably increase the cost of the frequency conversion control system

[0019] However, in terms of power factor improvement, this PFC method does not achieve the nearly 100% power factor effect of full-range active PFC, so its improvement is not satisfactory.

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