CN217335058U

CN217335058U - Overvoltage protection circuit structure for IC-CPD

Info

Publication number: CN217335058U
Application number: CN202123329643.5U
Authority: CN
Inventors: 倪似松; 张贞远; 井党林
Original assignee: Delphi Electrical Centers Shanghai Co Ltd
Current assignee: Delphi Electrical Centers Shanghai Co Ltd
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2022-08-30
Anticipated expiration: 2031-12-28

Abstract

The utility model relates to an overvoltage crowbar structure for IC-CPD, include the interchange overvoltage protection unit that is connected with the AC power end, wherein, the AC power end is connected to direct current overvoltage crowbar, transformer respectively through rectifier module, and direct current overvoltage crowbar is connected with the transformer. Compared with the prior art, the utility model discloses a construct dual overvoltage protection, can reliably realize the input overvoltage protection of rifle that charges, avoid the rifle that charges to take place the product damage because of the input excessive pressure.

Description

Overvoltage protection circuit structure for IC-CPD

Technical Field

The utility model belongs to the technical field of the rifle technique that charges and specifically relates to an overvoltage crowbar structure for IC-CPD is related to.

Background

As electric vehicles become popular, safety regulations for charging electric vehicles become more and more strict, and as is well known, electric vehicle charging has four modes, one of which is prohibited by the introduction due to failure to provide effective protection; on the basis of the first mode, a protection box (IC-CPD, In cable control and protection device) is arranged on the charging cable, and display and protection can be performed when fault current is generated; in the third mode, charging is carried out in an alternating current charging pile mode; and in the fourth mode, the charging is carried out in a direct current charging pile mode.

In the second mode, the IC-CPD is a control and protection device integrating current detection, input voltage detection, ground detection and RCD detection, and for the charging gun in the second mode, the standard input of the charging gun is a single-phase 220V input voltage, but in actual application, a terminal customer has a condition of being connected to a power grid privately, so that a condition of being connected to three phases of 380V may occur.

SUMMERY OF THE UTILITY MODEL

The objective of the present invention is to provide an overvoltage protection circuit structure for IC-CPD to overcome the above-mentioned drawbacks of the prior art, so as to reliably realize the input overvoltage protection of the charging gun.

The purpose of the utility model can be realized by the following technical proposal: an overvoltage protection circuit structure for an IC-CPD comprises an alternating current overvoltage protection unit connected with an alternating current power supply end, wherein the alternating current power supply end is respectively connected to a direct current overvoltage protection unit and a transformer through a rectifier module, and the direct current overvoltage protection unit is connected with the transformer.

Further, the alternating-current overvoltage protection unit comprises a first voltage dependent resistor, a second voltage dependent resistor and a third voltage dependent resistor, wherein the first voltage dependent resistor and the third voltage dependent resistor are connected in series and then connected in parallel with the second voltage dependent resistor.

Further, the alternating current power supply end comprises an L end, an N end and a PE end, the PE end is connected to the connection position of the first voltage dependent resistor and the third voltage dependent resistor, and the L end and the N end are respectively connected to the two ends of the second voltage dependent resistor.

Further, the rectification module is specifically LMB 10S.

Further, the direct current overvoltage protection unit comprises an ACDC chip, and the ACDC chip is connected to the output end of the rectification module through the voltage division sampling module.

Further, the partial pressure sampling module includes first resistance, second resistance, third resistance, fourth resistance and the fifth resistance that connects gradually in series, the one end of first resistance is connected to rectifier module's output, the one end ground connection of fifth resistance.

Furthermore, a capacitor is connected in parallel to two ends of the fifth resistor, and one ungrounded end of the fifth resistor is connected to the ACDC chip.

Furthermore, the ACDC chip is integrated with an MOS tube, and the drain electrode of the MOS tube is respectively connected with the output end of the rectification module and the transformer.

Further, the ACDC chip is specifically NCP1075AAP 065G.

Further, the specific models of the first piezoresistor, the second piezoresistor and the third piezoresistor are all B72214X2351K 504.

The utility model discloses a concrete theory of operation does: three piezoresistors arranged in the alternating-current overvoltage protection unit are used as voltage type protection devices, and when the transient input voltage is higher than the threshold value of the piezoresistor, the transient input voltage is characterized by instantaneous short circuit, so that a leakage switch at the alternating-current power supply end can be disconnected in a linkage manner, and a rear-stage circuit is protected from being damaged;

the ACDC chip arranged in the direct current overvoltage protection unit is connected to the output end of the rectifier module through the partial pressure sampling module, when the direct current output by the rectifier module is higher than a set threshold value, the ACDC chip stops working, the transformer at the rear stage also stops voltage reduction and conversion, and meanwhile flyback voltage is superposed on the ACDC chip, so that the product damage caused by overhigh input voltage of the protection chip is avoided.

Compared with the prior art, the utility model discloses a set up interchange overvoltage protection unit and direct current overvoltage protection unit to form dual overvoltage protection, utilize the interchange overvoltage protection unit to improve the pressure resistance of rifle that charges on the one hand, avoid exchanging the excessive pressure and cause the product to damage, on the other hand utilizes direct current overvoltage protection unit to realize inputing overvoltage protection, further avoids the rifle that charges to receive the direct current excessive pressure and takes place to damage.

Drawings

FIG. 1 is a schematic circuit diagram of an embodiment of an AC overvoltage protection unit;

fig. 2 is a schematic circuit diagram of the dc overvoltage protection unit in the embodiment.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Example (b):

an overvoltage protection circuit structure for an IC-CPD comprises an alternating current overvoltage protection unit connected with an alternating current power supply end, wherein the alternating current power supply end is respectively connected to a direct current overvoltage protection unit and a transformer through a rectifier module, and the direct current overvoltage protection unit is connected with the transformer.

As shown in fig. 1, the ac overvoltage protection unit includes a first varistor RV1, a second varistor RV2, and a third varistor RV3, the ac power source includes an L terminal, an N terminal, and a PE terminal, the first varistor RV1 is connected in series with the third varistor RV3 and then connected in parallel with the second varistor RV2, the PE terminal is connected to a connection position of the first varistor RV1 and the third varistor RV3, and the L terminal and the N terminal are connected to two terminals of the second varistor RV2 respectively. The voltage-type protection device comprises three piezoresistors RV1, RV2 and RV3, and is characterized by instantaneous short circuit when transient input voltage is higher than a threshold value of the piezoresistor, so that a rear-stage circuit is protected from being damaged.

As shown in fig. 2, the dc overvoltage protection unit includes an ACDC chip U8, and the ACDC chip U8 is connected to the output terminal of the rectifier module D27 through a voltage division sampling module. The voltage division sampling module comprises a first resistor R202, a second resistor R203, a third resistor R204, a fourth resistor R205 and a fifth resistor R201 which are sequentially connected in series, one end of the first resistor R202 is connected to the output end of the rectifying module D27, and one end of the fifth resistor R201 is grounded;

a capacitor C143 is connected in parallel with two ends of the fifth resistor R201, and one ungrounded end of the fifth resistor R201 is connected to a pin BO/AC _ OVP 2 of the ACDC chip U8;

pins 1 and 3 of the ACDC chip U8 are connected to a power supply VCC through capacitors C147 and C107;

the ACDC chip U8 is integrated with MOS tube, and the drain of MOS tube, i.e. 5 feet of U8, is connected with DC input and primary side of transformer T1 respectively.

In this embodiment, the ACDC chip U8 is specifically NCP1075AAP065G, and the rectifier module D27 is specifically LMB 10S.

The rectifier module D27 converts the alternating current into direct current, overvoltage detection is carried out on the direct current by using the ACDC chip, if the direct current is detected to exceed a set direct current overvoltage threshold value, the ACDC stops working, the transformer T1 stops step-down conversion, and otherwise, the transformer T1 further reduces the direct current to convert the direct current into charging direct current voltage.

According to the actual application requirements, the resistance values of the first piezoresistor to the third piezoresistor and the direct current overvoltage threshold value set in the ACDC chip can be set correspondingly.

Claims

1. The overvoltage protection circuit structure for the IC-CPD is characterized by comprising an alternating current overvoltage protection unit connected with an alternating current power supply end, wherein the alternating current power supply end is respectively connected to a direct current overvoltage protection unit and a transformer through a rectification module, and the direct current overvoltage protection unit is connected with the transformer.

2. The structure of claim 1, wherein the ac overvoltage protection unit comprises a first voltage dependent resistor, a second voltage dependent resistor, and a third voltage dependent resistor, and the first voltage dependent resistor is connected in series with the third voltage dependent resistor and then connected in parallel with the second voltage dependent resistor.

3. An overvoltage protection circuit structure for an IC-CPD according to claim 2, wherein said ac power source terminal comprises an L terminal, an N terminal and a PE terminal, said PE terminal is connected to the connection position of the first varistor and the third varistor, said L terminal and said N terminal are respectively connected to the two terminals of the second varistor.

4. The overvoltage protection circuit structure for the IC-CPD according to claim 1, wherein the DC overvoltage protection unit comprises an ACDC chip, and the ACDC chip is connected to the output end of the rectification module through a voltage division sampling module.

5. The IC-CPD overvoltage protection circuit structure according to claim 4, wherein the voltage division sampling module comprises a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor which are connected in series in sequence, one end of the first resistor is connected to the output end of the rectification module, and one end of the fifth resistor is grounded.

6. The structure of claim 5, wherein a capacitor is connected in parallel to two ends of the fifth resistor, and a non-grounded end of the fifth resistor is connected to the ACDC chip.

7. The structure of claim 4, wherein the ACDC chip is integrated with a MOS transistor, and a drain of the MOS transistor is connected to the output terminal of the rectifying module and the transformer, respectively.

8. An overvoltage protection circuit structure for IC-CPD according to any one of claims 4 to 7, wherein said ACDC chip is NCP1075AAP 065G.

9. An overvoltage protection circuit structure for an IC-CPD according to any one of claims 2 to 3, wherein the specific models of the first, second and third piezoresistors are all B72214X2351K 504.

10. An overvoltage protection circuit structure for IC-CPD according to any one of claims 1 to 7, wherein said rectifying module is specifically LMB 10S.