CN108528240B

CN108528240B - Electric energy conversion system and electric automobile

Info

Publication number: CN108528240B
Application number: CN201810240343.3A
Authority: CN
Inventors: 刘立志; 曹永霞; 蒋荣勋
Original assignee: Beijing Electric Vehicle Co Ltd
Current assignee: Beijing Electric Vehicle Co Ltd
Priority date: 2018-03-22
Filing date: 2018-03-22
Publication date: 2020-06-19
Anticipated expiration: 2038-03-22
Also published as: CN108528240A

Abstract

The invention provides an electric energy conversion system and an electric automobile, relates to the technical field of motors, and solves the problem that a signal ground wire and even electronic parts are burnt when a DC/DC output loop passes through a low-voltage signal ground wire in the prior art. The electric energy conversion system comprises a DC/DC and a storage battery, wherein the anode of the DC/DC is connected with the anode of the storage battery, the cathode of the DC/DC is connected with a grounding of an automobile body, the cathode of the storage battery is connected with the grounding, the cathode of the DC/DC and a high-voltage integrated main control board are connected through a standby ground wire, the high-voltage integrated main control board and a low-voltage plug connector are connected through a low-voltage plug connector and the cathode of the storage battery, and the cross section area of the standby ground wire is larger than that of a signal ground wire. When the DC/DC negative electrode is in fault with the grounding connection, a current loop can be formed between the DC/DC and the storage battery through the standby ground wire, so that the signal ground wire and even electronic parts are prevented from being burnt, and the high-voltage system is prevented from being in fault.

Description

Electric energy conversion system and electric automobile

Technical Field

The invention relates to the technical field of motors, in particular to an electric energy conversion system and an electric automobile.

Background

The vehicle-mounted direct current-to-direct current power supply DC/DC of the electric automobile gets electricity from the high-voltage power battery, converts high voltage into low voltage, charges the low-voltage storage battery, ensures that the low-voltage storage battery has sufficient electric quantity to supply power for low-voltage electric appliances of the whole automobile, and is a key link for realizing energy conversion from the high-voltage power battery to the low-voltage storage battery.

In practical application, as shown in fig. 1a, the DC/DC is more integrated into the high-voltage integrated system, and the positive electrode of the DC/DC output is directly connected with the positive electrode of the low-voltage battery through the external wiring harness of the high-voltage integrated system; the negative electrode is connected to the housing of the high-voltage integrated system through a bonding, and is connected to the negative electrode of the low-voltage battery through the bonding of the housing of the high-voltage integrated system and the vehicle body, and the DC/DC current flows to the arrow in FIG. 1 a. In the production and use processes of the high-voltage integrated system, if the grounding connection between the DC/DC negative electrode and the high-voltage integrated system shell is in fault (such as loose installation or poor contact), a current loop cannot be formed between the DC/DC and the storage battery through the path, and a large current can form a loop through a signal ground wire of a low-voltage plug connector, a signal ground wire of other electronic components in the high-voltage integrated system, such as an On Board Charger (OBC) or a Micro Controller Unit (MCU), as shown by an arrow in fig. 1b, at this time, the peak value of the DC/DC output current can exceed 100A and is far higher than the peak current which can be borne by the low-voltage signal ground wire, so that the low-voltage signal ground wire and even other electronic components are burned, thereby causing the fault of the high-voltage system and affecting the driving of the whole vehicle.

Disclosure of Invention

The invention aims to provide an electric energy conversion system and an electric automobile, and solves the problems that in the prior art, when a DC/DC output loop passes through a low-voltage signal ground wire, the low-voltage signal ground wire and other electronic parts are burnt, so that a high-voltage system is in failure, and the driving of the whole automobile is influenced.

In order to solve the technical problem, an embodiment of the invention provides an electric energy conversion system, which comprises a direct current-to-direct current power supply DC/DC and a storage battery, wherein an anode of the DC/DC is connected with an anode of the storage battery, a cathode of the DC/DC is connected with a bonding of an automobile body, a cathode of the storage battery is connected with the bonding, a cathode of the DC/DC and a high-voltage integrated main control board, a cathode of the high-voltage integrated main control board and a cathode of the low-voltage plug connector are connected through a standby ground wire, and a cross-sectional area of the standby ground wire is larger than that of a signal ground wire.

Optionally, the method further includes:

the current sampler is arranged on the high-voltage integrated main control board and used for collecting current on the standby ground wire;

and when the current collected by the current sampler is higher than a preset threshold value, the high-voltage integrated main control board controls the DC/DC to stop working.

Optionally, the high-voltage integrated main control board is further connected with the vehicle control unit, and when the current collected by the current sampler is higher than a preset threshold, the high-voltage integrated main control board sends fault information to the vehicle control unit.

Optionally, the standby ground wire arranged on the high-voltage integrated main control board is a copper-clad wire.

Optionally, the other standby ground wires except the standby ground wire arranged on the high-voltage integrated main control board are connected in parallel by a plurality of signal ground wires.

Optionally, the ground is connected with a shell of the high-voltage integrated system;

the DC/DC, the storage battery, the grounding and the shell of the high-voltage integrated system form a first loop;

the DC/DC, the storage battery, the low-voltage plug connector and the high-voltage integrated main control board form a second loop.

Optionally, a product of the loop impedance of the first loop and the impedance coefficient of the first loop is smaller than the loop impedance of the second loop.

Optionally, the negative electrode of the DC/DC is connected to the negative electrode of the storage battery sequentially through a signal ground wire of an electronic component in the high-voltage integrated system and a signal ground wire of the low-voltage plug connector;

the DC/DC, the storage battery, the low-voltage plug connector and the electronic part form a third loop.

Optionally, a product of the loop impedance of the third loop and the impedance coefficient of the third loop is greater than the loop impedance of the second loop.

In order to solve the above technical problem, an embodiment of the present invention further provides an electric vehicle, including: an electrical energy conversion system according to any preceding claim.

The technical scheme of the invention has the following beneficial effects:

the electric energy conversion system comprises a DC/DC and a storage battery, wherein the positive pole of the DC/DC is connected with the positive pole of the storage battery, the negative pole of the DC/DC is connected with a grounding piece of an automobile body, the negative pole of the storage battery is connected with the grounding piece, the negative pole of the DC/DC is connected with a high-voltage integrated main control board, the high-voltage integrated main control board is connected with a low-voltage plug connector, the low-voltage plug connector is connected with the negative pole of the storage battery through standby ground wires, and the cross section area of the standby ground wires is larger than that of a signal ground wire. At the moment, the DC/DC, the storage battery, the low-voltage plug connector and the high-voltage integrated main control board form a standby loop through a standby ground wire, and if the grounding connection of the DC/DC negative electrode and the high-voltage integrated system shell is failed, a current loop can be formed between the DC/DC and the storage battery through the standby loop. The spare ground wire is thick, so that the large current can not burn down through the spare loop in short time, the low-voltage signal ground wire and other electronic parts are prevented from being burnt down when the DC/DC output loop passes through the low-voltage signal ground wire, the high-voltage system fault is avoided, the normal driving of the whole vehicle is ensured, and the safety is improved.

Drawings

FIG. 1a is a schematic diagram of a conventional DC/DC output circuit;

FIG. 1b is another schematic diagram of a conventional DC/DC output circuit;

FIG. 2 is a schematic structural diagram of an electrical energy conversion system according to an embodiment of the present invention;

fig. 3 is a flowchart of a fault detection process of a high voltage integrated main control board in the electric energy conversion system according to the embodiment of the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the following detailed description is given with reference to the accompanying drawings and specific embodiments.

Referring to fig. 2, the electric energy conversion system according to the embodiment of the present invention includes a DC-to-DC power supply DC/DC and a storage battery, wherein a positive electrode of the DC/DC is connected to a positive electrode of the storage battery, a negative electrode of the DC/DC is connected to a ground of an automobile body, a negative electrode of the storage battery is connected to the ground, a negative electrode of the DC/DC is connected to a high-voltage integrated main control board, a high-voltage integrated main control board and a low-voltage plug connector, and a negative electrode of the storage battery through a backup ground wire, and a cross-sectional area of the backup ground wire is larger than a cross-sectional area of a signal ground wire.

According to the electric energy conversion system provided by the embodiment of the invention, the design of a standby ground is added in the low-voltage signal system, the DC/DC, the storage battery, the low-voltage plug connector and the high-voltage integrated main control board form a standby loop through the standby ground wire, and if the grounding connection of the DC/DC negative electrode and the high-voltage integrated system shell is failed, a current loop can be formed between the DC/DC and the storage battery through the standby loop. The spare ground wire is thick, so that the large current can not burn down through the spare loop in short time, the low-voltage signal ground wire and other electronic parts are prevented from being burnt down when the DC/DC output loop passes through the low-voltage signal ground wire, the high-voltage system fault is avoided, the normal driving of the whole vehicle is ensured, and the safety is improved.

Optionally, the electric energy conversion system of the embodiment of the present invention further includes:

the current sampler is arranged on the high-voltage integrated main control board and used for collecting current on the standby ground wire; and when the current collected by the current sampler is higher than a preset threshold value, the high-voltage integrated main control board controls the DC/DC to stop working.

At the moment, when the connection of the DC/DC output circuit is in a problem, large current can pass through a circuit formed by the standby ground wire for a short time without causing burning, meanwhile, a current sampler on the high-voltage integrated main control board can collect current on the standby ground wire, and when the current is higher than a preset threshold value, the high-voltage integrated main control board can judge that the connection of the DC/DC negative electrode and the grounding is in a fault and stop the DC/DC work, so that more serious consequences are avoided.

The preset threshold value can be set according to requirements, and any reasonable value can be adopted as the preset threshold value.

At the moment, the current sampler on the high-voltage integrated main control board can collect the current on the standby ground wire, when the current is higher than a preset threshold value, the high-voltage integrated main control board can judge that the DC/DC negative electrode connection fails, stop the DC/DC work, and send the fault information of the DC/DC ground fault to the vehicle control unit, so that serious accidents of burning of signal wires and other electronic equipment can be avoided, a user can timely know the fault information for maintenance, and normal driving is guaranteed.

The high-voltage integrated main control board CAN be connected with the vehicle Controller through a Controller Area Network (CAN).

As shown in fig. 3, the flow of the fault detection processing of the high-voltage integrated main control board includes: s31: the high-voltage integrated touch panel acquires current on the standby ground wire acquired by the current sampler; s32: the high-voltage integrated touch panel carries out filtering processing on the current on the standby ground wire; s33: the high-voltage integrated touch panel judges whether the current after filtering is higher than a preset threshold value; s34: if so, sending a work stopping signal to the DC/DC, prohibiting the DC/DC from driving and outputting, and informing the fault information of the DC/DC ground fault of the whole vehicle controller through the CAN; if not, the process is ended. When the current is higher than the preset threshold value, the high-voltage integrated main control board can judge that the DC/DC negative electrode is in fault with the grounding connection, stop the DC/DC work, and send fault information of the DC/DC grounding fault to the whole vehicle controller, so that serious accidents of burning of signal lines and other electronic equipment can be avoided, a user can timely know the fault information to maintain, and normal driving is guaranteed.

The fault detection processing flow of the high-voltage integrated main control board can be realized by a single chip microcomputer on the high-voltage integrated main control board.

In this case, the spare ground wire on the high-voltage integrated main control board can be realized by using a thicker copper-clad wire.

In this case, the spare ground wires other than the spare ground wire provided on the high-voltage integrated main control board, for example, the spare ground wire on the low-voltage connector, may be implemented by connecting a plurality of signal ground wires in parallel.

Optionally, the ground is connected with a shell of the high-voltage integrated system; the DC/DC, the storage battery, the grounding and the shell of the high-voltage integrated system form a first loop; the DC/DC, the storage battery, the low-voltage plug connector and the high-voltage integrated main control board form a second loop.

At the moment, the DC/DC, the storage battery, the grounding and the shell of the high-voltage integrated system form a first loop, when the DC/DC negative electrode is connected with the grounding, a current loop can be formed between the DC/DC and the storage battery through the first loop, and the DC/DC works normally; the DC/DC, the storage battery, the low-voltage plug connector and the high-voltage integrated main control board form a second loop through a standby ground wire, if the DC/DC negative pole is in fault with a grounding connection, a current loop can be formed between the DC/DC and the storage battery through the second loop, and the standby ground wire is thick, so that the high current can not be burnt out through the standby loop in short time, and the low-voltage signal ground wire and even other electronic parts are prevented from being burnt out when the DC/DC output loop passes through the low-voltage signal ground wire.

Optionally, a product of the loop impedance R _ normal of the first loop and the impedance coefficient K1 of the first loop is smaller than the loop impedance R _ backup of the second loop.

At this time, K1R _ normal < R _ backup, the loop impedance R _ backup of the backup loop (i.e. the second loop) formed by the backup ground wire is higher than the loop impedance R _ normal of the grounding loop (i.e. the first loop), when no problem occurs in connection of the DC/DC negative electrode and grounding, the current preferentially selects the low-impedance loop to form a closed loop, i.e. the grounding loop is preferentially selected to form the closed loop, so that the normal driving output of the DC/DC is ensured.

Optionally, the negative electrode of the DC/DC is connected to the negative electrode of the storage battery sequentially through a signal ground wire of an electronic component in the high-voltage integrated system and a signal ground wire of the low-voltage plug connector; the DC/DC, the storage battery, the low-voltage plug connector and the electronic part form a third loop.

The product of the loop impedance R _ signal of the third loop and the impedance coefficient K2 of the third loop is larger than the loop impedance R _ backup of the second loop.

In this case, the DC/DC, the battery, the low-voltage connector, and the electronic component constitute a third circuit via a signal ground. K1R _ normal < R _ back < K2R _ signal, the loop impedance R _ back of the standby loop (namely the second loop) formed by the standby ground wire is higher than the loop impedance R _ normal of the grounding loop (namely the first loop) but lower than the loop impedance R _ signal of any other signal ground wire loop (namely the third loop), when the connection of the DC/DC negative pole and the grounding fails, the current preferentially selects the low impedance loop to form a closed loop, namely the signal ground wire loop is preferentially selected to form a closed loop, thereby avoiding the burnout of the low-voltage signal ground wire and even other electronic parts when the DC/DC output loop passes through the low-voltage signal ground wire.

Among them, K1 and K2 can be determined by experimental tests, and K1 and K2 can take any reasonable values.

According to the electric energy conversion system provided by the embodiment of the invention, the design of the standby ground is added in the low-voltage signal system, and when the DC/DC output negative electrode is in fault with the grounding connection, the current preferentially selects the low-impedance loop to form a closed loop and flows through the standby ground loop. At the moment, the large current can not be burnt out through the standby ground loop in a short time, the current in the standby ground loop is obviously higher than a normal value, the high-voltage integrated system main control board processor can judge that the connection between the DC/DC output negative electrode and the grounding is in fault, the DC/DC operation is stopped, and fault information is sent to the whole vehicle controller. The electric energy conversion system avoids serious accidents of burning of signal wires and other electronic and electrical equipment, avoids high-voltage system faults, ensures normal driving of the whole vehicle, enables a user to timely acquire fault information for maintenance, and improves safety.

In the prior art, no mature DC/DC output circuit connection detection scheme exists, the problem is mostly avoided through the control of the detection and inspection of the production process of a high-voltage integrated system, but the potential risk cannot be fundamentally eliminated, and the detection scheme is more difficult to guarantee in the subsequent long-term application and maintenance process of a vehicle. The electric energy conversion system of the embodiment of the invention designs a DC/DC output cathode connection fault detection scheme, and can fundamentally, accurately and comprehensively detect poor connection of the DC/DC output cathode and break the fault.

Because the electric energy conversion system of the embodiment of the invention is applied to the electric automobile, the embodiment of the invention also provides the electric automobile, which comprises the following components: an electrical energy conversion system as described in the above embodiments. The implementation embodiments of the electric energy conversion system are all applicable to the embodiment of the electric vehicle, and the same technical effect can be achieved.

In various embodiments of the present invention, it should be understood that the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

In embodiments of the present invention, modules may be implemented in software for execution by various types of processors. An identified module of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions which may, for instance, be constructed as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together, but may comprise disparate instructions stored in different bits which, when joined logically together, comprise the module and achieve the stated purpose for the module.

Indeed, a module of executable code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Likewise, operational data may be identified within the modules and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network.

When a module can be implemented by software, considering the level of existing hardware technology, a module implemented by software may build a corresponding hardware circuit to implement a corresponding function, without considering cost, and the hardware circuit may include a conventional Very Large Scale Integration (VLSI) circuit or a gate array and an existing semiconductor such as a logic chip, a transistor, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. An electric energy conversion system comprises a direct current-to-direct current power supply DC/DC and a storage battery, wherein the positive pole of the DC/DC is connected with the positive pole of the storage battery, the negative pole of the DC/DC is connected with a grounding of an automobile body, and the negative pole of the storage battery is connected with the grounding,

the negative electrode of the DC/DC is connected with the high-voltage integrated main control board, the high-voltage integrated main control board is connected with the low-voltage plug connector, and the low-voltage plug connector is connected with the negative electrode of the storage battery through standby ground wires, wherein the cross section area of the standby ground wires is larger than that of the signal ground wire;

and the other standby ground wires except the standby ground wire arranged on the high-voltage integrated main control board are connected in parallel by adopting a plurality of signal ground wires.

2. The electrical energy conversion system of claim 1, further comprising:

3. The electric energy conversion system according to claim 2, wherein the high-voltage integrated main control board is further connected with a vehicle control unit, and when the current collected by the current sampler is higher than a preset threshold value, the high-voltage integrated main control board sends fault information to the vehicle control unit.

4. The electrical energy conversion system of claim 1, wherein the backup ground disposed on the high voltage integrated main control board is a copper-clad wire.

5. The electrical energy conversion system of claim 1, wherein the ground is connected to a housing of a high voltage integrated system;

6. The electrical energy conversion system of claim 5, wherein a product of a loop impedance of the first loop and an impedance coefficient of the first loop is less than a loop impedance of the second loop.

7. The electrical energy conversion system of claim 6, wherein the negative pole of the DC/DC is connected to the negative pole of the battery sequentially via a signal ground of an electronic component in the high voltage integrated system and a signal ground of the low voltage plug connector;

8. The electrical energy conversion system of claim 7, wherein a product of a loop impedance of the third loop and an impedance coefficient of the third loop is greater than a loop impedance of the second loop.

9. An electric vehicle, comprising: an electrical energy conversion system according to any one of claims 1 to 8.