A rectifying and filtering device and method for suppressing power-on surge current

Abstract

The invention provides a rectification and filtering device for suppressing power-on surge current. The rectification and filtering device comprises a first rectification circuit, a relay, a filtering capacitor and a zero-crossing conduction control circuit for detecting zero crossing points of an alternating current and controlling the relay. The relay comprises a coil and a contact point. A first end of the first rectification circuit is connected with one end of the contact point; the other end of the contact point is connected with one end of the filtering capacitor; the other end of the filtering capacitor and a second end of the first rectification circuit are grounded; the two ends of the coil are connected with the two ends of the zero-crossing conduction control circuit respectively; the other two ends of the zero-crossing conduction control circuit are connected with the two ends of the alternating current respectively; and the other two ends of the zero-crossing conduction control circuit are further connected with a third end and a fourth end of the first rectification circuit respectively. The invention also relates to a method by utilizing the device above. By applying the rectification and filtering device and method for suppressing the power-on surge current, the following beneficial effects can be achieved: the appearance of surge current can be completely eliminated, and hardware cost is reduced.

Description

technical field [0001] The invention relates to the field of rectification and filtering, in particular to a rectification and filtering device and method for suppressing power-on surge current. Background technique [0002] At present, in the general bridge rectifier filter circuit, there will be a large-capacity electrolytic capacitor (see figure 1 In E), at the moment when the power is turned on, since the initial voltage on the electrolytic capacitor is zero, it is equivalent to the electrolytic capacitor is in a "short circuit" state, and a large voltage will be generated on the circuit at this time Instantaneous inrush current (sometimes up to hundreds of amperes, see Figure 7 In b), the greater the capacity of the electrolytic capacitor, the greater the voltage at the moment of power-on, and the greater the inrush current. This will have a great impact on the grid and other electrical equipment on the grid, as well as the electronic components on its own current lo...

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a method for suppressing power-on inrush current that can completely eliminate the occurrence of inrush current and reduce hardware cost in view of the above-mentioned defects in the prior art that cannot completely eliminate the occurrence of inrush current and increase hardware costs. Rectification and filtering device and method

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