Charge bleed-off method, bleeder circuit and converter

Abstract

The invention discloses a charge bleed-off method, a bleeder circuit and a converter. The bleeder circuit disclosed by the invention includes a bleed resistor and a control switch connected with the bleed resistor in series, wherein the bleeder circuit is connected with a bus capacitor of the converter in parallel; and the bleed resistor and the control switch are connected between an anode and a cathode of a DC bus of the converter. According to the invention, a bleed-off function of residual charges of a voltage on the DC bus can be controlled in the case of shutdown of the converter: the bleeder circuit is not accessed when the converter works normally; and the bleeder circuit is automatically accessed when the converter is shut down to bleed off the residual charges on the DC bus in time. When the converter works normally, the bleeder circuit is cut off, and the bleed resistor generates no heat. Accordingly, by adopting the embodiment of the invention, unnecessary losses are reduced on one hand, and on the other hand, the internal temperature of the converter will not rise, so that the reliability of the system is improved.

Description

technical field [0001] The invention relates to the field of converters, in particular to a charge discharge method, a discharge circuit and a converter. Background technique [0002] The main topology of the converter used in the existing high-power frequency conversion centrifuge unit usually adopts the "AC-DC-AC" structure. figure 1 It is the main structure diagram of the current converter used in the existing high-power frequency conversion centrifuge unit. Such as figure 1 As shown, the rectification module 1 and the inverter module 2 of the converter are connected through a DC bus 3 . For AC input, a DC potential is established through the rectifier module 1, and a relatively large bus capacitor 4 is connected to the intermediate link, that is, the DC bus 3 for energy storage. [0003] When the converter is working, a relatively high voltage is established on the DC bus 3 , and when the converter stops, the residual charge on the DC bus 3 needs to be discharged thro...

AI Technical Summary

Problems solved by technology

[0003] When the converter is working, a relatively high voltage is established on the DC bus 3. When the converter stops, the residual charge on the DC bus 3 needs to be discharged through the discharge circuit, otherwise there will be safety hazards

The currently used solution is to directly connect the bleeder resistor 5 at both ends of the DC bus 3 to realize this function. No matter in what state, as long as there is voltage on the DC bus 3, energy will be consumed on the bleeder resistor 5, resulting in energy waste , and the heating of the resistor will increase the internal temperature of the converter

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