CN212353633U - Pre-charging device, battery thermal management system and electric automobile - Google Patents

Abstract

The utility model relates to a pre-charging device, battery thermal management system and electric automobile. Wherein, pre-charge device sets up between power and load, and pre-charge device includes: the circuit board to and set up fuse, pre-charge unit and the filter unit on the circuit board, wherein, the fuse electricity is connected between the input of power and pre-charge unit, and the filter unit electricity is connected between the output and the load of pre-charge unit. The utility model provides a poor problem of reliability of pre-charge device among the correlation technique, have the technological effect who has improved the reliability of pre-charge device.

Description

Pre-charging device, battery thermal management system and electric automobile

Technical Field

The utility model relates to a battery technology field especially relates to a pre-charging device, battery thermal management system and electric automobile.

Background

With the support of national policies and the rapid advance of electric vehicle development, people pay more and more attention to the electrical safety of the electric vehicle. The load of the existing battery thermal management system can generate larger impact current when the voltage is high, the impact current can reduce the service life of a relay in a circuit, even damage a relay and cause the relay to be adhered, and larger potential safety hazards are brought to the operation of the system. In order to prevent safety problems caused by short circuit of a loop, a high-voltage fuse (fuse) is often added in a high-voltage circuit, and the fuse is difficult to meet the waterproof requirement of IP67 or has higher cost when meeting the requirement of IP67 due to the limitation of process conditions during installation in a unit; meanwhile, when the battery thermal management unit is powered on at high voltage, the fluctuation can generate interference in the system, low-voltage communication is influenced, even the low-voltage communication error frame is frequently generated, the system frequently reports faults, and the system operation is seriously influenced.

In order to solve the above problems, in the prior art, three circuits, namely a fuse circuit, a pre-charging circuit and a filter circuit, are added at the front end of a load (a compressor, a PTC, a DC \ DC). These three circuits are respectively provided on three circuit boards and electrically connected using high-voltage connectors. In the research process, the fact that three circuit boards are manufactured respectively causes more parts and increases the manufacturing cost; further, the high-voltage connector is liable to fail due to poor contact or aging, resulting in poor reliability of the entire circuit.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is necessary to provide a precharge device, a battery thermal management system, and an electric vehicle, in order to solve the problem of poor reliability of the precharge device in the related art.

According to a first aspect of the present application, there is provided a precharge device provided between a power supply and a load, the precharge device including: the circuit board, and set up fuse, pre-charge unit and filter unit on the circuit board, wherein, the fuse electricity is connected in between the power with the input of pre-charge unit, the filter unit electricity is connected in between the output of pre-charge unit and the load.

In one embodiment, the precharge unit includes: the circuit comprises a first branch circuit, a second branch circuit and a first capacitor, wherein a first switch and a current-limiting subunit are connected in series on the first branch circuit; a second switch is connected in series on the second branch; the first branch and the second branch are connected between a first connecting node and a second connecting node in parallel, and the fuse is electrically connected between the first connecting node and the positive electrode of the power supply; one end of the first capacitor is electrically connected to the second connection node, and the other end of the first capacitor is electrically connected to the negative electrode of the power supply.

In one embodiment, the current limiting subunit includes: a resistor, or a plurality of resistors connected in parallel.

In one embodiment, a diode is further connected in series to the first branch, wherein a cathode of the diode is electrically connected to the second connection node, and an anode of the diode is electrically connected to one end of the current limiting subunit.

In one embodiment, the precharge unit further includes: and the third switch is connected between the other end of the first capacitor and the negative electrode of the power supply in series.

In one embodiment, the filtering unit includes: the first winding of the common mode inductor is electrically connected between the output end of the pre-charging unit and one end of the second capacitor, and the second winding of the common mode inductor is electrically connected between the negative electrode of the power supply and the other end of the second capacitor.

In one embodiment, the filtering unit further includes: the capacitor comprises a third capacitor and a fourth capacitor, wherein one end of the third capacitor is electrically connected to one end of the second capacitor, the other end of the third capacitor is electrically connected to one end of the fourth capacitor, the other end of the fourth capacitor is electrically connected to the other end of the second capacitor, and the joint of the third capacitor and the fourth capacitor is grounded.

In one embodiment, the pre-charging device further comprises a housing, wherein the housing is filled with insulating glue, and the circuit board is hermetically arranged in the insulating glue.

According to a second aspect of the present application, there is provided a battery thermal management system comprising: a battery and a load, and the pre-charging device of any of the above embodiments, the pre-charging device being electrically connected between the battery and the load.

According to a third aspect of the present application, there is provided an electric vehicle including: electric automobile body and the battery thermal management system of any one of the above embodiments.

The precharge device solves the problem of poor reliability of the precharge device in the related art, and has the technical effect of improving the reliability of the precharge device.

Drawings

Fig. 1 is a circuit topology diagram of a precharge device according to an embodiment of the present application.

Reference numerals: 1. fuse, 2, precharge unit, 3, filtering unit, 4, load, 21, first switch, 22, second switch, 23, third switch, 24, second resistor, 25, first resistor, 26, diode, 27, first capacitor, 31, common mode inductance, 32, second capacitor, 33, third capacitor, 34, fourth capacitor, 35, ground.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Based on the examples in the utility model, all other examples that ordinary skilled person in the art obtained under the prerequisite of not making the creative work all belong to the scope of protection of the utility model.

It is obvious that the drawings in the following description are only examples or embodiments of the application, from which the application can also be applied to other similar scenarios without inventive effort for a person skilled in the art. Moreover, it should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the specification. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

Unless otherwise defined, technical or scientific terms used in the claims and the specification should have the ordinary meaning as understood by those of ordinary skill in the art to which this application belongs. The use of the terms "a" and "an" and "the" and similar referents in the context of describing and claiming the application are not to be construed as limiting in any way, but rather as indicating the singular or plural. The word "comprise" or "comprises", and the like, means that the element or item listed before "comprises" or "comprising" covers the element or item listed after "comprising" or "comprises" and its equivalent, and does not exclude other elements or items. "connected" or "coupled" and similar terms are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. As used in the specification and claims of this application, "a plurality" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship.

As shown in fig. 1, in one embodiment, there is provided a precharge device provided between a power supply and a load 4, the precharge device including: the circuit board to and fuse 1, pre-charge unit 2 and the filter unit 3 that set up on the circuit board, wherein, fuse 1 electricity is connected between the input of power and pre-charge unit 2, and filter unit 3 electricity is connected between the output of pre-charge unit 2 and load 4.

In the related technology, three parts including a fuse 1, a pre-charging unit 2 and a filtering unit 3 are often adopted, two pairs of high-voltage connectors and a part of high-voltage wire harnesses are used for connection, the cost is high, the number of parts is large, and the risk of water inflow at the connection position is increased. The fuse 1, the pre-charging unit 2 and the filtering unit 3 are integrated, redundant and repeated circuits are reduced, the system cost is greatly reduced, and the problems of resource waste, insufficient protection function and low reliability are solved; meanwhile, in the embodiment, the fuse 1, the pre-charging unit 2 and the filtering unit 3 are integrated on the circuit board, and the fuse 1, the pre-charging unit 2 and the filtering unit 3 are not connected by a high-voltage connector, so that the risk of water inflow at the connection part of the fuse 1, the pre-charging unit 2 and the filtering unit 3 is reduced; place filter unit 3 in precharge unit 2's back, when avoiding filter unit 3 to place in precharge unit 2's front, the electric capacity in filter unit 3 produces impulse current when the electricity and leads to having great electric current on the bus, if there is the relay on the bus, has the risk that leads to the relay to glue, burns out the fuse on the bus or the load 4 of being connected with the bus even.

In one embodiment, the precharge unit 2 includes: first branch road, second branch road and first electric capacity 27, wherein, first switch 21 and current-limiting subunit are established ties on the first branch road, and the current-limiting subunit includes: a resistor, or a plurality of resistors connected in parallel; the second branch is connected with a second switch 22 in series, the first branch and the second branch are connected between the first connection node and the second connection node in parallel, and the fuse 1 is electrically connected between the first connection node and the positive pole of the power supply; one end of the first capacitor 27 is electrically connected to the second connection node, and the other end of the first capacitor 27 is electrically connected to the negative electrode of the power supply.

In this embodiment, when the pre-charging device powers on the load 4, the first switch 21 is first closed, and in order to reduce the current during closing, the current limiting subunit adopts the first resistor 25 and the second resistor 24 connected in parallel, so that the second resistor 24 divides a part of the current, thereby avoiding the resistor from being burnt due to too large current when a single resistor is used; the first capacitor 27 is connected in parallel with the load 4, after the voltage of the first capacitor 27 is stabilized, the second switch 22 is closed, the first switch 21 is opened, and at the moment, the second switch 22 cannot be impacted by large current, so that the second switch 22 is prevented from being adhered.

In one embodiment, a diode 26 is further connected in series to the first branch, wherein a cathode of the diode 26 is electrically connected to the second connection node, and an anode of the diode 26 is electrically connected to one end of the current limiting subunit.

In this embodiment, the diode 26 is connected in series to the first branch, so that it is avoided that when the first switch 21 and the second switch 22 are closed, the first capacitor 27 has a larger current flowing back to cause the second switch 22 to be adhered, thereby causing an electrical accident, wherein in this embodiment, the first switch 21 and the second switch 22 may both adopt a high-voltage relay.

In one embodiment, the precharge unit 2 further includes: and a third switch 23, wherein the third switch 23 is connected in series between the other end of the first capacitor 27 and the negative electrode of the power supply.

In the related art, the second switch 22 of the pre-charging unit 2 is powered on to effectively avoid the inrush current, but when the second switch 22 is turned off, the first capacitor 27 may discharge, possibly damaging the second switch 22. In this embodiment, the third switch 23 is serially connected between the negative electrode of the power supply and the first capacitor 27, and when the main switch is in an adhesion accident, the circuit of the pre-charging device can be disconnected through the third switch 23, so as to effectively protect the electrical appliance of the load 4 and prevent the electrical appliance from being burnt, wherein in this embodiment, the third switch 23 may adopt a high-voltage relay.

In one embodiment, the filtering unit 3 includes: a common mode inductor 31 and a second capacitor 32, wherein a first winding of the common mode inductor 31 is electrically connected between the output terminal of the pre-charging unit 2 and one end of the second capacitor 32, and a second winding of the common mode inductor 31 is electrically connected between the negative electrode of the power supply and the other end of the second capacitor 32.

In one embodiment, the filtering unit 3 further includes: and one end of the third capacitor 33 is electrically connected to one end of the second capacitor 32, the other end of the third capacitor 33 is electrically connected to one end of the fourth capacitor 34, the other end of the fourth capacitor 34 is electrically connected to the other end of the second capacitor 32, and the connection between the third capacitor 33 and the fourth capacitor 34 is grounded.

In this embodiment, the load 4 is disposed at the output end of the filtering unit 3, when the common mode interference occurs, the magnetic flux directions of the two coils of the common mode inductor 31 are the same, the total inductance is rapidly increased after coupling, the common mode signal presents a large inductance, the ac burr part of the input voltage is filtered by using the characteristic that the inductance leads to the dc resistance, the characteristic that the capacitance leads to the ac resistance, and the connection between the third capacitor 33 and the fourth capacitor 34 is grounded, so that part of the ac current is grounded and filtered, in this embodiment, the second capacitor 32 may be a thin film capacitor for filtering the series mode interference, and the third capacitor 33 and the fourth capacitor 34 may be ceramic capacitors.

In one embodiment, the pre-charging device further comprises a housing, wherein the housing is filled with insulating glue, and the circuit board is hermetically arranged in the insulating glue.

In this embodiment, the fuse 1, the pre-charging unit 2, and the filtering unit 3 are integrated on one circuit board, and in order to meet the waterproof requirement of IP67, the circuit board is hermetically disposed inside the housing after the circuit board is molded, and the waterproof capability of the pre-charging device is improved by filling insulating glue between the housing and the circuit board.

The working process of the pre-charging device is as follows:

when the power supply is ready to supply power to the load 4, the controller firstly controls the third switch 23 to be closed, and then controls the first switch 21 to be closed, and at the moment when the first switch 21 is closed, the first current limiting subunit and the second current limiting subunit are connected in parallel to enable the second current limiting subunit to obtain a part of current; the first capacitor 27 is connected in parallel with the load 4, after the voltage of the first capacitor 27 is stabilized, the second switch 22 is closed, the first switch 21 is disconnected, the first capacitor 27 inputs the voltage to the filtering unit 3, the load 4 is arranged at the output end of the filtering unit 3, when common-mode interference occurs, the magnetic flux directions of two coils of the common-mode inductor 31 are the same, the total inductance is rapidly increased after coupling, the common-mode signal presents very large inductive reactance, the alternating current of the inductor is utilized to filter the alternating current burr part of the input voltage, the alternating current of the capacitor is utilized to filter the direct current of the alternating current resistor, and the connection part of the third capacitor 33 and the fourth capacitor 34 is grounded, so that part of the alternating current is grounded and filtered, and finally the filtered voltage is input to the load 4 by the filtering unit 3.

In one embodiment, there is provided a battery thermal management system comprising: the battery and the load 4, and the pre-charging device as in any of the above embodiments, the pre-charging device being electrically connected between the battery and the load 4.

When a pre-charging device in the battery thermal management system powers on a load 4, a first switch 21 is closed, and in order to reduce current during closing, a first resistor 25 and a second resistor 24 are connected in parallel on a current limiting subunit, so that the second resistor 24 divides a part of current; the first capacitor 27 is connected in parallel with the load 4, after the voltage of the first capacitor 27 is stabilized, the second switch 22 is closed, the first switch 21 is opened, and at the moment, the second switch 22 cannot be impacted by large current, so that the second switch 22 is prevented from being adhered; meanwhile, the diode 26 is arranged on the first branch, so that the phenomenon that when the first switch 21 and the second switch 22 are closed, the first capacitor 27 has larger current backflow to cause the second switch 22 to be adhered to cause an electrical accident is avoided; the load 4 is arranged at the output end of the filter unit 3, when common-mode interference occurs, the magnetic flux directions of two coils of the common-mode inductor 31 are the same, the total inductance value is rapidly increased after coupling, the common-mode signal presents very large inductance, the alternating current part of the input voltage is filtered by utilizing the alternating current resistance characteristic of the inductance, the alternating current burr part of the input voltage is filtered by utilizing the alternating current resistance characteristic of the capacitance, and the connection part of the third capacitor 33 and the fourth capacitor 34 is grounded, so that part of the alternating current is grounded and filtered, the third capacitor 33 adopts a film capacitor for filtering series mode interference, and the third capacitor 33 and the fourth capacitor 34 adopt ceramic capacitors; by arranging the third switch 23 in series between the negative electrode of the power supply and the first capacitor 27, when the main switch is adhered, the circuit of the pre-charging device can be disconnected through the third switch 23, so that the electric appliance of the load 4 is effectively protected, and the electric appliance is prevented from being burnt; in the embodiment, in order to meet the waterproof requirement of IP67, after the circuit board is molded, the circuit board is hermetically disposed inside the housing, and the insulating glue is filled between the inside of the housing and the circuit board to improve the waterproof capability of the pre-charging device; finally, the filtered voltage is input to the load 4 by the filtering unit 3.

In the above embodiment, the load 4 may be, but is not limited to, at least one of the following: compressor, PTC (water heating heater), DC-DC converter.

In one embodiment, there is also provided an electric vehicle including: electric automobile body and foretell battery thermal management system.

The battery thermal management system provided in this embodiment has already been described in detail in the above embodiment of the battery thermal management system, and is not described here again.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above examples only represent some embodiments of the present invention, and the description thereof is more specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims (10)

1. A pre-charge apparatus disposed between a power source and a load, the pre-charge apparatus comprising: the circuit board, and set up fuse, pre-charge unit and filter unit on the circuit board, wherein, the fuse electricity is connected in between the power with the input of pre-charge unit, the filter unit electricity is connected in between the output of pre-charge unit and the load.

2. A precharge apparatus according to claim 1, wherein said precharge unit comprises: the circuit comprises a first branch circuit, a second branch circuit and a first capacitor, wherein a first switch and a current-limiting subunit are connected in series on the first branch circuit; a second switch is connected in series on the second branch; the first branch and the second branch are connected between a first connecting node and a second connecting node in parallel, and the fuse is electrically connected between the first connecting node and the positive electrode of the power supply; one end of the first capacitor is electrically connected to the second connection node, and the other end of the first capacitor is electrically connected to the negative electrode of the power supply.

3. A pre-charging apparatus as claimed in claim 2, wherein the current limiting sub-unit comprises: a resistor, or a plurality of resistors connected in parallel.

4. A pre-charging apparatus according to claim 2, wherein a diode is further connected in series to the first branch, wherein a cathode of the diode is electrically connected to the second connection node, and an anode of the diode is electrically connected to one end of the current limiting sub-unit.

5. A precharge apparatus according to claim 2, wherein said precharge unit further comprises: and the third switch is connected between the other end of the first capacitor and the negative electrode of the power supply in series.

6. A precharge apparatus according to claim 1, wherein said filter unit comprises: the first winding of the common mode inductor is electrically connected between the output end of the pre-charging unit and one end of the second capacitor, and the second winding of the common mode inductor is electrically connected between the negative electrode of the power supply and the other end of the second capacitor.

7. A pre-charging apparatus according to claim 6, wherein the filtering unit further comprises: the capacitor comprises a third capacitor and a fourth capacitor, wherein one end of the third capacitor is electrically connected to one end of the second capacitor, the other end of the third capacitor is electrically connected to one end of the fourth capacitor, the other end of the fourth capacitor is electrically connected to the other end of the second capacitor, and the joint of the third capacitor and the fourth capacitor is grounded.

8. A pre-charging device according to any one of claims 1 to 7, further comprising a housing, wherein the housing is filled with an insulating glue, and the circuit board is hermetically disposed in the insulating glue.

9. A battery thermal management system, comprising: a battery and a load, and a pre-charging device as claimed in any one of claims 1 to 8 electrically connected between the battery and the load.

10. An electric vehicle, comprising: an electric vehicle body and a battery thermal management system as in claim 9.

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