阅读说明：本技术 一种新能源汽车用锂电池与铅酸电池并联系统及控制方法 (Lithium battery and lead-acid battery parallel system for new energy automobile and control method ) 是由 陈�峰 陈洪图 于 2019-09-24 设计创作，主要内容包括：本发明公开了一种新能源汽车用锂电池与铅酸电池并联系统及控制方法,该系统包括综合控制电路以及分别与综合控制电路电气连接的单层电压采集电路、电流采集电路、过流及过充主动保护电路和CAN通信电路。本发明将新能源汽车的锂电池和铅酸电池作为整个电池系统进行并联控制,不仅能让锂电池和铅酸电池充分互补和发挥,增加了汽车电池系统的放电倍率,有效提高了使用寿命和效率,而且系统整体构成简单,电路保护功能好,在大幅提高车辆综合运行性能的同时,可靠性可以得到保证。(The invention discloses a lithium battery and lead-acid battery parallel system for a new energy automobile and a control method. According to the invention, the lithium battery and the lead-acid battery of the new energy automobile are used as the whole battery system to be controlled in parallel, so that the lithium battery and the lead-acid battery can be fully complemented and exerted, the discharge rate of the automobile battery system is increased, the service life and the efficiency are effectively improved, the whole system is simple in structure, the circuit protection function is good, and the reliability can be ensured while the comprehensive running performance of the automobile is greatly improved.)

1. The utility model provides a lithium cell and lead acid battery parallel system for new energy automobile which characterized in that: the device comprises a comprehensive control circuit (1), and a single-layer voltage acquisition circuit (2), a current acquisition circuit (3), an overcurrent and overcharge active protection circuit (4), a CAN communication circuit (5) and a temperature acquisition circuit (6) which are respectively electrically connected with the comprehensive control circuit (1); wherein the content of the first and second substances,

the integrated control circuit (1) is responsible for collecting and analyzing various voltage information, current information and external communication information about the battery system, and generating and outputting various corresponding control instructions and external communication information;

the single-layer voltage acquisition circuit (2) is responsible for acquiring the total voltage of the battery system in real time and feeding voltage parameters back to the comprehensive control circuit (1);

the current acquisition circuit (3) consists of a total current detection circuit (301) and a lithium battery working current detection circuit (302); the total current detection circuit (301) is responsible for collecting the total current of the battery system in real time and feeding back the total current parameter to the comprehensive control circuit (1); the lithium battery working current detection circuit (302) is responsible for collecting the partial current of a lithium battery part in the battery system in real time and feeding back the partial current parameters of the lithium battery to the comprehensive control circuit (1);

the overcurrent and overcharge active protection circuit (4) is responsible for actively turning off a protection switch under the control of the comprehensive control circuit (1) when a battery system is in a short circuit or overcharge condition, cutting off a charge and discharge loop to protect the safety of the battery system, and feeding back the state of the protection switch to the comprehensive control circuit (1);

the CAN communication circuit (5) is responsible for sending communication information to the outside under the control of the comprehensive control circuit (1), and inputting the communication information to the comprehensive control circuit (1) after receiving the external communication information so as to realize real-time information interaction with other CAN nodes of the vehicle;

the temperature acquisition circuit (6) is responsible for acquiring the battery temperature of a lithium battery part in the battery system and feeding back temperature parameters to the comprehensive control circuit (1).

2. The lithium battery and lead-acid battery parallel system for the new energy automobile as claimed in claim 1, wherein: and the single-layer voltage acquisition circuit (2) conducts corresponding electric cores through the optical-mechanical electrical device switch array to perform voltage sampling.

3. The lithium battery and lead-acid battery parallel system for the new energy automobile as claimed in claim 1, wherein: the current collecting circuit (3) adopts a current divider as a current sensor and respectively collects the total current of the battery system and the divided current of the lithium battery part in the battery system.

4. The lithium battery and lead-acid battery parallel system for the new energy automobile as claimed in claim 1, wherein: the overcurrent and overcharge active protection circuit (4) comprises a thermal protection switch connected in series in a charge and discharge loop and a heating device for disconnecting the thermal protection switch, and the overcurrent and overcharge active protection circuit (4) supplies power to the thermal protection switch through the heating device for heating so as to actively disconnect the charge and discharge loop.

5. The lithium battery and lead-acid battery parallel system for the new energy automobile as claimed in claim 1, wherein: the CAN communication circuit (5) sends communication information including alarm signals and lithium battery state information to the outside.

6. A control method of a lithium battery and lead-acid battery parallel system for a new energy automobile is characterized by comprising the following steps:

step 1) when a parallel system is powered on, automatically performing self-checking work, wherein the self-checking work comprises the steps of detecting the initial voltage of a battery system through a single-layer voltage acquisition circuit (2), detecting the initial temperature of the battery system through a temperature acquisition circuit (6), detecting the initial state of a protection switch through an overcurrent and overcharge active protection circuit (4), respectively feeding back the initial voltage, the initial temperature and the initial state of the protection switch of the battery system to a comprehensive control circuit (1), and immediately entering the initial state of the parallel system to wait for the start of a vehicle;

step 2) in the running process of a vehicle, a current acquisition circuit (3) acquires the total current of a battery system and the working current of a lithium battery part in real time, a temperature acquisition circuit (6) acquires the working temperature of the lithium battery part in real time, a single-layer voltage acquisition circuit (2) acquires the total voltage of the battery system in real time, and respectively feeds back the working current, the working temperature and the total voltage of the battery system to the comprehensive control circuit (1), and the comprehensive control circuit (1) analyzes and monitors the state of the battery system in real time;

step 3) when the integrated control circuit (1) detects one or more abnormal conditions of over-temperature, over-current or over-voltage of the battery system, the integrated control circuit (1) firstly carries out alarm processing through the CAN communication circuit (5), sends out an alarm signal and then carries out countdown of time delay triggering active protection;

step 4) if the working temperature, the working current and the total voltage of the battery system are immediately recovered to normal values before the countdown of the delay triggering active protection is finished, the comprehensive control circuit (1) is in contact with an alarm through the CAN communication circuit (5);

and step 5) if the working temperature, the working current or the total voltage of the battery system are still at abnormal values after the countdown of the delay triggered active protection is finished, the comprehensive control circuit (1) immediately controls a heating device in the overcurrent and overcharge active protection circuit (4) to work while sending out an alarm signal, and heats a thermal protection switch connected in series in the charge and discharge loop, the thermal protection switch is immediately turned off after being heated, the charge and discharge loop is immediately and actively disconnected, and the battery system is actively protected to avoid safety accidents.

7. The method for controlling the parallel system of the lithium battery and the lead-acid battery for the new energy automobile as claimed in claim 6, wherein the reciprocal time of the time delay triggered active protection is set to 2 ~ 5 seconds.

8. The control method of the parallel system of the lithium battery and the lead-acid battery for the new energy automobile according to claim 6, characterized in that: after the active protection of the battery system is executed, the comprehensive control circuit (1) sends the state of the battery system to other CAN node units of the whole vehicle through the CAN communication circuit (5) to notify the state of the battery system.

Technical Field

The invention belongs to the technical field of new energy automobiles, and particularly relates to a lithium battery and lead-acid battery parallel system for a new energy automobile and a control method.

Background

Nowadays, countries around the world have higher and higher requirements on automobile exhaust emission and fuel economy, which forces automobile manufacturers to widely popularize a 'black technology' capable of saving fuel and reducing emission, and the automatic start-stop system is so born. The automatic start-stop system mainly comprises an enhanced starter, an enhanced storage battery, a SISS direct injection ignition starting engine, a BSG power generation starting all-in-one machine and an ISG integrated motor/generator. The automatic start-stop system is provided with the function from tens of thousands of miniature cars to millions of sports cars only in the beginning of the domestic wind and water.

Specifically, the automatic start-stop system is called Idle-stop Idle stop system, and the engine is started through an enhanced starter and an enhanced storage battery. Because the mode is not greatly different from the common vehicle starting mode, the storage battery and the starter need to bear larger pressure, more sensors and controllers are needed for detection and control, the used storage battery is particularly strengthened to be capable of being rapidly charged and discharged, and meanwhile, the storage battery also needs to have larger capacity to deal with the working use of electric appliances in the vehicle after the engine is stopped.

The common lead-acid storage battery is limited by the characteristics of the common lead-acid storage battery, large current can not be discharged for many times in a short time, and the partition plate can not allow the electric ions to pass through quickly, so that the two main starting and stopping problems of a starting and stopping system, namely large current and frequent output, are difficult to solve at present, the self-discharge rate of the lead-acid storage battery is high, the discharge rate per month is 3 ~ 5%, the storage period exceeds 6 months, the supplementary charging is needed, and the service life is short.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a lithium battery and lead-acid battery parallel system for a new energy automobile and a control method, which enable the lithium battery and the lead-acid battery to be fully complemented and exerted so as to increase the discharge rate of the automobile battery system, effectively prolong the service life and improve the efficiency.

In order to solve the technical problems and achieve the technical effects, the invention is realized by the following technical scheme:

a lithium battery and lead-acid battery parallel system for a new energy automobile comprises a comprehensive control circuit, and a single-layer voltage acquisition circuit, a current acquisition circuit, an overcurrent and overcharge active protection circuit, a CAN communication circuit and a temperature acquisition circuit which are electrically connected with the comprehensive control circuit respectively; wherein the content of the first and second substances,

the integrated control circuit is responsible for collecting and analyzing various voltage information, current information and external communication information related to the battery system, and generating and outputting various corresponding control instructions and external communication information;

the single-layer voltage acquisition circuit is responsible for acquiring the total voltage of the battery system in real time and feeding voltage parameters back to the comprehensive control circuit;

the current acquisition circuit consists of a total current detection circuit and a lithium battery working current detection circuit; the total current detection circuit is responsible for collecting the total current of the battery system in real time and feeding back the total current parameter to the comprehensive control circuit; the lithium battery working current detection circuit is responsible for collecting the partial current of the lithium battery part in the battery system in real time and feeding back the partial current parameters of the lithium battery to the comprehensive control circuit;

the overcurrent and overcharge active protection circuit is in charge of actively turning off the protection switch under the control of the comprehensive control circuit when the battery system is in a short circuit or overcharge condition, disconnecting the charging and discharging loop to protect the safety of the battery system and feeding back the state of the protection switch to the comprehensive control circuit;

the CAN communication circuit is responsible for sending communication information to the outside under the control of the comprehensive control circuit, and the communication information is input into the comprehensive control circuit after receiving the outside communication information so as to realize real-time information interaction with other CAN nodes of the vehicle;

the temperature acquisition circuit is responsible for acquiring the battery temperature of a lithium battery part in the battery system and feeding back temperature parameters to the comprehensive control circuit.

Furthermore, the single-layer voltage acquisition circuit conducts corresponding electric cores through the optical-mechanical electrical device switch array to perform voltage sampling.

Furthermore, the current collecting circuit adopts a current divider as a current sensor to respectively collect the total current of the battery system and the branch current of the lithium battery part in the battery system.

Furthermore, the overcurrent and overcharge active protection circuit comprises a thermal protection switch connected in series in the charge and discharge loop and a heating device for disconnecting the thermal protection switch, and the overcurrent and overcharge active protection circuit supplies external power to the thermal protection switch through the heating device for heating so as to actively disconnect the charge and discharge loop.

Further, the CAN communication circuit sends communication information to the outside, wherein the communication information comprises an alarm signal and lithium battery state information.

A control method of a lithium battery and lead-acid battery parallel system for a new energy automobile specifically comprises the following steps:

step 1) when a parallel system is powered on, automatically performing self-checking work, wherein the self-checking work comprises the steps of detecting the initial voltage of a battery system through a single-layer voltage acquisition circuit, detecting the initial temperature of the battery system through a temperature acquisition circuit, detecting the initial state of a protection switch through an overcurrent and overcharge active protection circuit, respectively feeding back the initial voltage, the initial temperature and the initial state of the protection switch of the battery system to a comprehensive control circuit, and immediately entering the initial state of the parallel system to wait for the start of a vehicle;

step 2) in the running process of the vehicle, a current acquisition circuit acquires the total current of the battery system and the working current of the lithium battery part in real time, a temperature acquisition circuit acquires the working temperature of the lithium battery part in real time, a single-layer voltage acquisition circuit acquires the total voltage of the battery system in real time and respectively feeds the working current, the working temperature and the total voltage of the battery system back to the comprehensive control circuit, and the comprehensive control circuit analyzes and monitors the state of the battery system in real time;

step 3) when the integrated control circuit detects one or more abnormal conditions of over-temperature, over-current or over-voltage of the battery system, the integrated control circuit firstly carries out alarm processing through the CAN communication circuit, sends out an alarm signal and then carries out countdown of time delay triggering active protection;

step 4) if the working temperature, the working current and the total voltage of the battery system are immediately recovered to normal values before the countdown of the delayed trigger active protection is finished, the comprehensive control circuit is in contact with an alarm through the CAN communication circuit;

and 5) if the working temperature, the working current or the total voltage of the battery system are still at abnormal values after the countdown of the delay triggered active protection is finished, the comprehensive control circuit immediately controls a heating device in the overcurrent and overcharge active protection circuit to work while sending out an alarm signal, and heats a thermal protection switch connected in series in the charge and discharge loop, the thermal protection switch is immediately turned off after being heated, the charge and discharge loop is immediately and actively disconnected, and the battery system is actively protected to avoid safety accidents.

Further, the reciprocal time of the delay triggering active protection is set at 2 ~ 5 seconds.

Furthermore, after the active protection of the battery system is executed, the comprehensive control circuit sends the state of the battery system to other CAN node units of the whole vehicle through the CAN communication circuit to notify the state of the battery system.

Compared with the prior art, the invention has the beneficial effects that:

according to the invention, the lithium battery and the lead-acid battery of the new energy automobile are used as the whole battery system to be controlled in parallel, so that the lithium battery and the lead-acid battery can be fully complemented and exerted, the discharge rate of the automobile battery system is increased, the service life and the efficiency are effectively improved, the whole system is simple in structure, the circuit protection function is good, and the reliability can be ensured while the comprehensive running performance of the automobile is greatly improved.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings. The detailed description of the present invention is given in detail by the following examples and the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

fig. 1 is a control logic block diagram of a lithium battery and lead-acid battery parallel system for a new energy automobile.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings in conjunction with embodiments. The description set forth herein is intended to provide a further understanding of the invention and forms a part of this application and is intended to be an exemplification of the invention and is not intended to limit the invention to the particular embodiments illustrated.

Referring to fig. 1, a lithium battery and lead-acid battery parallel system for a new energy automobile comprises a comprehensive control circuit 1, and a single-layer voltage acquisition circuit 2, a current acquisition circuit 3, an overcurrent and overcharge active protection circuit 4, a CAN communication circuit 5 and a temperature acquisition circuit 6 which are electrically connected with the comprehensive control circuit 1 respectively; wherein the content of the first and second substances,

the integrated control circuit 1 is responsible for collecting and analyzing various voltage information, current information and external communication information about the battery system, and generating and outputting various corresponding control instructions and external communication information;

the single-layer voltage acquisition circuit 2 is responsible for acquiring the total voltage of the battery system in real time and feeding voltage parameters back to the comprehensive control circuit 1;

the current acquisition circuit 3 consists of a total current detection circuit 301 and a lithium battery working current detection circuit 302; the total current detection circuit 301 is responsible for collecting the total current of the battery system in real time and feeding back the total current parameter to the integrated control circuit 1; the lithium battery working current detection circuit 302 is responsible for collecting the partial current of the lithium battery part in the battery system in real time and feeding back the partial current parameters of the lithium battery to the comprehensive control circuit 1;

the overcurrent and overcharge active protection circuit 4 is responsible for actively turning off a protection switch under the control of the comprehensive control circuit 1 when a battery system is in a short circuit or overcharge condition, disconnecting a charge and discharge loop to protect the safety of the battery system, and feeding back the state of the protection switch to the comprehensive control circuit 1;

the CAN communication circuit 5 is responsible for sending communication information to the outside under the control of the comprehensive control circuit 1, and inputting the communication information to the comprehensive control circuit 1 after receiving the external communication information so as to realize real-time information interaction with other CAN nodes of the vehicle;

the temperature acquisition circuit 6 is responsible for acquiring the battery temperature of a lithium battery part in the battery system and feeding back temperature parameters to the comprehensive control circuit 1.

Further, the single-layer voltage acquisition circuit 2 conducts the corresponding electric core through the optical-mechanical electrical device switch array to perform voltage sampling.

Further, the current collecting circuit 3 adopts a current divider as a current sensor to respectively collect the total current of the battery system and the branch current of the lithium battery part in the battery system.

Further, the overcurrent and overcharge active protection circuit 4 comprises a thermal protection switch connected in series in the charge and discharge loop and a heating device for disconnecting the thermal protection switch, and the overcurrent and overcharge active protection circuit 4 supplies power and heats the thermal protection switch through the heating device to actively disconnect the charge and discharge loop.

Further, the CAN communication circuit 5 sends communication information including an alarm signal and lithium battery status information to the outside.

A control method of a lithium battery and lead-acid battery parallel system for a new energy automobile specifically comprises the following steps:

step 1) when a parallel system is powered on, automatically performing self-checking work, wherein the self-checking work comprises the steps of detecting the initial voltage of a battery system through a single-layer voltage acquisition circuit 2, detecting the initial temperature of the battery system through a temperature acquisition circuit 6, detecting the initial state of a protection switch through an overcurrent and overcharge active protection circuit 4, respectively feeding back the initial voltage, the initial temperature and the initial state of the protection switch of the battery system to a comprehensive control circuit 1, and immediately entering the initial state of the parallel system to wait for the start of a vehicle;

step 2) in the running process of the vehicle, a current acquisition circuit 3 acquires the total current of the battery system and the working current of the lithium battery part in real time, a temperature acquisition circuit 6 acquires the working temperature of the lithium battery part in real time, a single-layer voltage acquisition circuit 2 acquires the total voltage of the battery system in real time, the working current, the working temperature and the total voltage of the battery system are respectively fed back to a comprehensive control circuit 1, and the comprehensive control circuit 1 analyzes and monitors the state of the battery system in real time;

step 3) when the integrated control circuit 1 detects one or more abnormal conditions of over-temperature, over-current or over-voltage of the battery system, the integrated control circuit 1 firstly carries out alarm processing through the CAN communication circuit 5, sends out an alarm signal and then carries out countdown of time delay triggering active protection;

step 4) if the working temperature, the working current and the total voltage of the battery system are immediately recovered to normal values within 2 ~ 5 seconds of the alarm signal, the comprehensive control circuit 1 contacts an alarm through the CAN communication circuit 5;

step 5) if the working temperature, the working current or the total voltage of the battery system are still at abnormal values after 2 ~ 5 seconds when the alarm signal is sent out, the comprehensive control circuit 1 immediately controls a heating device in the overcurrent and overcharge active protection circuit 4 to work while sending out the alarm signal, and heats a thermal protection switch connected in series in a charge and discharge loop, the thermal protection switch is immediately turned off after being heated, the charge and discharge loop is immediately and actively disconnected, and the battery system is actively protected to avoid safety accidents;

and 6) after the active protection of the battery system is executed, the comprehensive control circuit 1 sends the state of the battery system to other CAN node units of the whole vehicle through the CAN communication circuit 5 to notify the state of the battery system.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. 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.