CN218276174U - Pre-charging circuit - Google Patents

Abstract

The utility model provides a precharge circuit belongs to charging circuit technical field, and this precharge circuit comprises alternating current input AC end, bridge rectifier circuit, load circuit, inductance L, relay K, triode Q, electric capacity C and switch tube. The utility model discloses when the AC input AC end charges, its output alternating current, then realize the rectification through bridge rectifier circuit, then output direct current, inductance L absorbed energy when charging, the break-make process of continuous repetitive switch pipe, electric capacity C both ends obtain the high voltage then, driving voltage based on the switch pipe is the PWM signal, thereby the accessible is adjusted the frequency of PWM signal and is realized realizing the electric capacity C' S of realization to the relapse on-off control of switch pipe charging, above-mentioned process energy loss is minimum, the loss of energy has finally been reduced, pressure difference is minimum between the high pressure of above-mentioned electric capacity C both ends voltage and input, when contactor S is closed, the electric current is minimum in its return circuit, then can not lead to the fact the impact in contactor S and the return circuit.

Description

Pre-charging circuit

Technical Field

The utility model belongs to the technical field of charging circuit, concretely relates to precharge circuit.

Background

The vehicle-mounted charger is a device for charging the vehicle-mounted power battery, and the pre-charging of the vehicle-mounted power battery is generally divided into an alternating current pre-charging mode and a direct current pre-charging mode.

The granted publication number "CN211223073U" describes "a rectification driving circuit, which includes a pre-charging circuit, a thyristor circuit, a rectification circuit, an electrolytic capacitor, and a thyristor trigger circuit; the input of the rectification driving circuit is single-phase alternating current; a pre-charging circuit is connected in series between a live wire at the input end of the rectification driving circuit and an output end of a high-voltage direct current positive electrode, a zero line at the input end of the rectification driving circuit is connected with a rectification circuit, a silicon controlled rectifier circuit, a rectification circuit and an electrolytic capacitor are respectively connected in parallel between the high-voltage direct current positive electrode and the output end of a high-voltage direct current negative electrode, and a silicon controlled rectifier trigger circuit is connected with the silicon controlled rectifier circuit; the pre-charging circuit is used for charging the electrolytic capacitor, the silicon controlled trigger circuit is used for triggering the silicon controlled circuit, the silicon controlled circuit is used for charging the electrolytic capacitor, and the silicon controlled circuit and the rectifying circuit are used for rectifying the single-phase alternating current input.

The patent can avoid the performance limitation of mechanical devices in the prior art, and effectively realizes the pre-charging and rectification of the alternating current input side;

however, in the above patent, due to the pressure difference between the high voltage input and the electrolytic capacitor, a large current will be generated in the circuit, which will cause impact to the contactor and other devices in the circuit, easily damage the contactor and other devices, and have low safety.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a precharge circuit, the utility model discloses aim at solving the technical problem who provides among the prior art.

In order to achieve the above object, the utility model provides a following technical scheme:

a precharge circuit, comprising:

an AC input terminal;

the input end of the bridge rectifier circuit is electrically connected with the positive electrode of the alternating current input AC end, and the bridge rectifier circuit is used for realizing rectification and outputting alternating current as direct current;

one end of the inductor L is electrically connected with the output end of the bridge rectifier circuit;

the input end of the relay K is electrically connected with the other end of the inductor L;

the drain electrode of the triode Q is electrically connected with the other end of the relay K, and the grid electrode of the triode Q is electrically connected with a switching tube;

one end of the capacitor C is electrically connected with the output end of the relay K, and the other end of the capacitor C is electrically connected with the triode Q and then electrically connected with a GND (ground) end; and

and the load circuit is connected in parallel to one side of the capacitor C.

As an optimized scheme of the utility model, load circuit includes battery BT, load resistance R and contactor S, battery BT positive pole with load resistance R one end electricity is connected, the load resistance R other end with contactor S one end electricity is connected, the contactor S other end with electric capacity C one end electricity is connected, battery BT negative pole is connected with the GND earthing terminal electricity.

As an optimal scheme of the utility model, bridge rectifier circuit includes rectifier diode D1, rectifier diode D2, rectifier diode D3 and rectifier diode D4, flow input AC end positive pole respectively with rectifier diode D1 positive pole and rectifier diode D3 positive pole electricity is connected, rectifier diode D1 negative pole with rectifier diode D2 positive pole electricity is connected, rectifier diode D3 negative pole with rectifier diode D4 positive pole electricity is connected, rectifier diode D2 negative pole and rectifier diode D4 negative pole all with inductance L one end electricity is connected.

As an optimized scheme of the present invention, the triode Q employs a field effect transistor.

As an optimized scheme of the utility model, electric capacity C adopts polarity electric capacity.

As an optimized scheme of the present invention, the driving voltage of the switching tube is a PWM signal.

As a preferred scheme of the utility model, still include:

and the input end of the controller is electrically connected with the other end of the load resistor R, and the output end of the controller is electrically connected with the input end of the relay K.

Compared with the prior art, the beneficial effects of the utility model are that:

(1) The utility model discloses when AC input AC end charges, its output alternating current realizes the rectification through bridge rectifier circuit then, then outputs the direct current, inductance L absorbed energy during the charging, the break-make process of ceaselessly repetition switch tube, then electric capacity C both ends obtain the high voltage, drive voltage based on the switch tube is the PWM signal, then accessible regulation PWM signal's frequency realizes the repeated on-off control to the switch tube thereby realize the charging to electric capacity C, above-mentioned process energy loss is few, has finally reduced the loss of energy; the voltage difference between the voltage at the two ends of the capacitor C and the input high voltage is extremely small, when the contactor S is closed, the current in the loop is extremely small, and then the contactor S and components in the loop cannot be impacted, so that the safety of the whole pre-charging circuit is improved.

(2) The utility model discloses when the controller judges that the interchange side breaks down, it can in time break off relay K, switches it to the load side then, has effectively guaranteed the security performance of interchange side simultaneously

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic circuit diagram of a precharge circuit according to the present invention.

In the figure:

100. a bridge rectifier circuit;

200. a load circuit.

Detailed Description

The technical solution in the embodiment of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiment of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and all other embodiments obtained by those skilled in the art without any inventive work are within the scope of the present invention based on the embodiments of the present invention.

Example 1:

referring to fig. 1, the present invention provides the following technical solutions:

a pre-charging circuit comprises an AC input end, a bridge rectifier circuit 100, a load circuit 200, an inductor L, a relay K, a triode Q, a capacitor C and a switch tube, as explained in detail below

The bridge rectifier circuit 100, its input and the positive pole electrical connection of alternating current input AC end, it is used for realizing the rectification and exports alternating current as direct current, specifically: the bridge rectifier circuit 100 comprises a rectifier diode D1, a rectifier diode D2, a rectifier diode D3 and a rectifier diode D4, wherein the positive electrode of the current input AC end is electrically connected with the positive electrode of the rectifier diode D1 and the positive electrode of the rectifier diode D3 respectively, the negative electrode of the rectifier diode D1 is electrically connected with the positive electrode of the rectifier diode D2, the negative electrode of the rectifier diode D3 is electrically connected with the positive electrode of the rectifier diode D4, and the negative electrode of the rectifier diode D2 and the negative electrode of the rectifier diode D4 are electrically connected with one end of an inductor L;

one end of the inductor L is electrically connected with the output end of the bridge rectifier circuit 100;

the input end of the relay K is electrically connected with the other end of the inductor L;

the drain electrode of the triode Q is electrically connected with the other end of the relay K, the grid electrode of the triode Q is electrically connected with a switching tube, and preferably, the triode Q adopts a field effect transistor

One end of a capacitor C is electrically connected with the output end of the relay K, the other end of the capacitor C is electrically connected with the triode Q and then is electrically connected with a GND grounding end, and specifically, the capacitor C adopts a polar capacitor;

the load circuit 200 is connected in parallel to one side of the capacitor C, specifically, the load circuit 200 includes a battery BT, a load resistor R and a contactor S, the positive pole of the battery BT is electrically connected with one end of the load resistor R, the other end of the load resistor R is electrically connected with one end of the contactor S, the other end of the contactor S is electrically connected with one end of the capacitor C, and the negative pole of the battery BT is electrically connected with the GND ground end;

further, the driving voltage of the switching tube is a PWM signal;

the working principle or working process of the embodiment is as follows:

when the alternating current is input into the AC end for charging, the alternating current is output, then rectification is realized through the bridge rectifier circuit 100, direct current is output, the inductor L absorbs energy during charging, the on-off process of the switching tube is repeated continuously, then high voltage is obtained at two ends of the capacitor C, the driving voltage based on the switching tube is a PWM signal, and then repeated on-off control of the switching tube can be realized by adjusting the frequency of the PWM signal so as to realize charging of the capacitor C, the energy loss in the process is very little, and the energy loss is reduced finally;

the voltage difference between the voltage at the two ends of the capacitor C and the input high voltage is extremely small, when the contactor S is closed, the current in a loop is extremely small, so that the contactor S and components in the loop cannot be impacted, and the safety of the whole pre-charging circuit is improved;

example 2:

when the ac side fails in embodiment 1, it cannot be timely switched to the load for power supply, and the embodiment is additionally provided with a controller on the basis of embodiment 1, which is specifically set forth as follows:

the input end of the controller is electrically connected with the other end of the load resistor R, and the output end of the controller is electrically connected with the input end of the relay K;

when the controller judges that the alternating current side has a fault, the controller can disconnect the relay K in time and then switch the relay K to the load side, and meanwhile, the safety performance of the alternating current side is effectively guaranteed;

it should be noted that: the controller is provided with a corresponding voltage or current detection circuit to implement the above detection function, which can adopt the conventional technical means of those skilled in the art, so that the description thereof is omitted.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing embodiments, or equivalents may be substituted for elements thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (7)

1. A precharge circuit, comprising:

an AC input terminal;

a bridge rectifier circuit (100) having an input terminal electrically connected to the AC input AC terminal positive electrode, and configured to perform rectification to output AC power as dc power;

one end of the inductor L is electrically connected with the output end of the bridge rectifier circuit (100);

the input end of the relay K is electrically connected with the other end of the inductor L;

the drain electrode of the triode Q is electrically connected with the other end of the relay K, and the grid electrode of the triode Q is electrically connected with a switching tube;

one end of the capacitor C is electrically connected with the output end of the relay K, and the other end of the capacitor C is electrically connected with the triode Q and then electrically connected with a GND (ground) end; and

and the load circuit (200) is connected in parallel to one side of the capacitor C.

2. A pre-charge circuit according to claim 1, characterized in that the load circuit (200) comprises a battery BT, a load resistor R and a contactor S, wherein the positive pole of the battery BT is electrically connected with one end of the load resistor R, the other end of the load resistor R is electrically connected with one end of the contactor S, the other end of the contactor S is electrically connected with one end of the capacitor C, and the negative pole of the battery BT is electrically connected with the GND ground.

3. A pre-charging circuit according to claim 2, wherein the bridge rectifier circuit (100) comprises a rectifier diode D1, a rectifier diode D2, a rectifier diode D3 and a rectifier diode D4, the positive pole of the input AC terminal is electrically connected to the anode of the rectifier diode D1 and the anode of the rectifier diode D3 respectively, the cathode of the rectifier diode D1 is electrically connected to the anode of the rectifier diode D2, the cathode of the rectifier diode D3 is electrically connected to the anode of the rectifier diode D4, and the cathode of the rectifier diode D2 and the cathode of the rectifier diode D4 are electrically connected to one end of the inductor L.

4. A precharge circuit according to claim 3, wherein said transistor Q is a field effect transistor.

5. A pre-charging circuit according to claim 4, characterized in that said capacitor C is a polar capacitor.

6. A pre-charge circuit according to claim 5, wherein the driving voltage of the switch tube is a PWM signal.

7. A precharge circuit as claimed in claim 6, further comprising:

and the input end of the controller is electrically connected with the other end of the load resistor R, and the output end of the controller is electrically connected with the input end of the relay K.

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