CN207366715U - A kind of battery SOC estimation device based on CAN bus - Google Patents

Abstract

A battery SOC estimation device based on CAN bus, including a voltage detection module, a current detection module, a temperature detection module, an internal resistance measurement module, a microprocessor and a liquid crystal display module, as well as a CAN controller and a host computer with a CAN communication interface , the liquid crystal display module and the microprocessor all have a CAN communication interface, and the voltage detection module, the current detection module, the temperature detection module and the internal resistance measurement module are all provided with an AD conversion module and a CAN communication interface, and through the CAN communication interface Connect the CAN controller, the CAN controller is connected to the microprocessor, the microprocessor is connected to the upper computer and realizes data transmission through the CAN communication interface, and the microprocessor is connected to the liquid crystal display module and displays the battery status through the liquid crystal display module SOC value. The device uses CAN bus for communication, which has the following advantages: long transmission distance, fast transmission rate, can work in high noise interference environment and has strong error detection ability.

Description

A battery SOC estimation device based on CAN bus

technical field

The utility model relates to the field of electric vehicle power battery management systems, in particular to a battery SOC estimation device based on CAN bus.

Background technique

As the power source of electric vehicles, the performance and life of batteries directly affect the use of electric vehicles. Therefore, it is necessary to detect the status of various parameters of batteries in real time to ensure the safety of electric vehicles and prolong the service life of electric vehicles.

The state of charge (SOC) of the battery pack of an electric vehicle reflects the state of the remaining capacity of the battery pack, which can represent the mileage that the electric vehicle can continue to drive. However, the charging and discharging process of the battery is a complex electrochemical reaction process, so the state of charge of the battery cannot be directly measured, and the battery can only be estimated by measuring other battery parameters such as the voltage, current, temperature and internal resistance of the battery. state of charge.

The Chinese patent with the notification number CN202177690U discloses an electric vehicle battery SOC estimation device, including a voltage detection module, a current detection module, a battery temperature detection module, and an ambient temperature detection module respectively connected to the DSP control device. The DSP control device is connected, the DSP control device is connected with the microcomputer through serial port communication, the DSP control device is connected with the energy control system of the whole machine, and the display module, and the display module is provided with a manual switch for switching display. Among them, the voltage detection module, current detection module, battery temperature detection module, ambient temperature detection module, and internal resistance detection module respectively detect the voltage, current, battery temperature, ambient temperature, and battery internal resistance of the battery, and then the data is transmitted to the DSP control chip for processing , combined with EKF and neural network algorithms to estimate the SOC in real time, and at the same time, display the specific data through the display module. However, the device uses serial communication to transmit data and has the following disadvantages: low transmission rate, short transmission distance, weak anti-interference ability and error-prone data collection.

Utility model content

The purpose of this utility model is to provide a battery SOC estimation device based on CAN bus. The device uses CAN bus for communication, which has the following advantages: long transmission distance, fast transmission rate, can work in high noise interference environment and has error detection ability powerful.

The above technical purpose of the utility model is achieved through the following technical solutions: a battery SOC estimation device based on CAN bus, including a voltage detection module, a current detection module, a temperature detection module, an internal resistance measurement module, a microprocessor and a liquid crystal The display module also includes a CAN controller and a host computer with a CAN communication interface. Both the liquid crystal display module and the microprocessor have a CAN communication interface. The voltage detection module, the current detection module, the temperature detection module and the internal resistance measurement module Both are provided with an AD conversion module and a CAN communication interface, and are connected to a CAN controller through the CAN communication interface. The CAN controller is connected to a microprocessor, and the microprocessor is connected to an upper computer and realizes data transmission through the CAN communication interface. The microprocessor is connected with the liquid crystal display module and displays the SOC value of the battery through the liquid crystal display module.

By adopting the above technical solution, the CAN bus has a long transmission distance and a fast transmission rate, and can quickly collect and transmit a large amount of data, maintaining real-time data update. The CAN bus has an error detection function. The module that detects an error will immediately notify all other modules at the same time. Once the module that is sending a message detects an error, it will forcibly end the current transmission. The CAN bus also has an error recovery function, and the module that forcibly ends the sending will resend the message repeatedly until it is successfully sent. At the same time, the CAN bus can be fault-closed, and CAN can determine whether the type of error is a temporary data error on the bus (such as external noise, etc.) or a continuous data error (such as unit internal failure, driver failure, disconnection, etc.). With this function, when a persistent data error occurs on the bus, the module causing the failure can be isolated from the bus. The CAN bus and the program of the microprocessor cooperate with each other to realize a more accurate data acquisition function and ensure the reliability of the data.

It is further set as: the voltage detection module includes a voltage sensor, the voltage sensor is connected between the positive and negative bus bars of the power battery pack, and the output terminal of the voltage sensor is connected to the AD conversion module; the current detection module includes a current sensor, The current sensor is connected in series on the positive busbar of the power battery pack, and the output end of the current sensor is connected with the AD conversion module; the temperature detection module includes a temperature sensor, which is attached to the surface of the power battery pack, and the output end of the temperature sensor is connected to the The AD conversion modules are connected; the internal resistance measurement module includes an internal resistance measuring instrument, which is connected in series with the positive and negative bus bars of the power battery pack, and the output end of the internal resistance measuring instrument is connected with the AD conversion module.

By adopting the above technical scheme, corresponding data can be collected, wherein the voltage value of the power battery pack is collected through the voltage detection module and converted into a corresponding digital signal through the AD conversion module; the current value of the power battery pack is collected through the current detection module and converted into corresponding digital signals through the AD conversion module; the temperature value of the power battery pack is collected through the temperature detection module and converted into corresponding digital signals through the AD conversion module; the internal resistance value of the power battery pack is collected through the internal resistance measurement module And through the AD conversion module into the corresponding digital signal.

Description of drawings

Fig. 1 is a structural block diagram of the embodiment.

In the figure: 1. Power battery pack; 2. Voltage detection module; 3. Current detection module; 4. Temperature detection module; 5. Internal resistance measurement module; 6. CAN controller; 7. Microprocessor; 8. Liquid crystal display Module; 9. Host computer.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in further detail.

Referring to Figure 1, a battery SOC estimation device based on CAN bus, including a voltage detection module 2, a current detection module 3, a temperature detection module 4, an internal resistance measurement module 5, a microprocessor 7, a liquid crystal display module 8, and a CAN controller 6 and the upper computer 9 are both provided with a CAN communication interface, and are connected to the CAN bus through the CAN communication interface for data communication. The voltage detection module 2, the current detection module 3, the temperature detection module 4 and the internal resistance measurement module 5 are respectively connected to the CAN controller 6, the CAN controller 6 is connected to the microprocessor 7, and the microprocessor is connected to the upper computer 9 and the liquid crystal display module 8. The voltage detection module 2 , the current detection module 3 , the temperature detection module 4 and the internal resistance measurement module 5 are all provided with an AD conversion module.

Wherein: the voltage detection module 2 includes a voltage sensor, the voltage sensor is connected between the positive and negative busbars of the power battery pack 1, the output terminal of the voltage sensor is connected with the AD conversion module, and the AD conversion module can convert the detected voltage value Analog signals are converted into corresponding digital signals.

The current detection module 3 includes a current sensor, the current sensor is connected in series to the positive busbar of the power battery pack 1, the output terminal of the current sensor is connected to the AD conversion module, and the AD conversion module can convert the analog signal of the detected current value into a corresponding digital signal. The temperature detection module 4 includes a temperature sensor, the temperature sensor is attached to the surface of the power battery pack 1, the output end of the temperature sensor is connected with the AD conversion module, and the AD conversion module can convert the analog signal of the detected temperature value into a corresponding digital signal . The internal resistance measurement module 5 includes an internal resistance measuring instrument, which is connected in series to the positive and negative bus bars of the power battery pack 1, and the output end of the internal resistance measuring instrument is connected to the AD conversion module, which can detect the The analog signal of the resistance value is converted into a corresponding digital signal. The digital signal converted by AD can be transmitted to the CAN bus through the CAN communication interface, and received by the CAN controller 6 through the CAN bus. After the CAN controller 6 receives the digital signal, it is transmitted to the microprocessor 7 by the CAN bus. The microcontroller here preferably has a microprocessor 7 with the CAN controller 6, that is, the microprocessor 7 is internally provided with a CAN controller 6. At this time, the digital signal converted by AD will be directly transmitted to the CAN controller 6 inside the microprocessor 7, and there is no need to connect an independent CAN controller 6 chip externally, which can greatly simplify the hardware setting and production cost.

After the microprocessor 7 receives and processes the digital signal, it transmits it to the host computer 9 through the CAN bus. The upper computer 9 is provided with a trained neural network estimation module, and the SOC value of the battery can be obtained through accurate estimation. Since the state of charge of the battery cannot be directly measured, the state of charge of the battery can only be estimated by measuring other parameters of the battery. Therefore, the selection of parameters is particularly important when using the neural network estimation module to estimate the state of charge of the battery. Among them, the voltage, current, temperature and internal resistance of the battery have a great correlation with the state of charge of the battery. Therefore, collecting the above data can make the estimation accuracy of the neural network estimation module higher, and the neural network estimation module is applicable to any kind of The characteristics of battery SOC value can be accurately and real-time detected online without establishing a specific battery model. The upper computer 9 has a data saving function, and the user can draw relevant graphics based on the data, and observe the usage of the power battery pack 1 more directly. After the neural network estimation module estimates the SOC value, the data is transmitted to the microprocessor 7 through the CAN bus, and the microprocessor 7 is connected to the liquid crystal display module 8 and transmits the data to the liquid crystal display module 8 through the CAN bus. The LCD screen can display the SOC value of the power battery pack 1, as well as the temperature, current, voltage and internal resistance of the power battery pack 1, so that users can understand the usage status of the power battery of electric vehicles and the cruising range of the power battery . When the power battery is overcharged, overdischarged, or the surface temperature of the power battery is too high, the liquid crystal display module 8 can display the abnormal state of the battery to remind the user to stop for inspection or maintenance.

This specific embodiment is only an explanation of the utility model, and it is not a limitation of the utility model. Those skilled in the art can make modifications to the embodiment without creative contribution according to needs after reading this specification, but as long as they are within the utility model All new claims are protected by patent law.

Claims (2)

1. a kind of battery SOC estimation device based on CAN bus, including voltage detection module (2), current detection module (3), temperature Spend detection module (4), internal resistance measurement module (5), microprocessor (7) and LCD MODULE (8), it is characterised in that：Further include CAN controller (6) and the host computer (9) with CAN communication interface, the LCD MODULE (8) and microprocessor (7) are respectively provided with CAN communication interface, the voltage detection module (2), current detection module (3), temperature detecting module (4) and internal resistance measurement module (5) AD conversion module and CAN communication interface are both provided with, and CAN controller (6), the CAN are connected by CAN communication interface Controller (6) connection microprocessor (7), microprocessor (7) the connection host computer (9) simultaneously realize number by CAN communication interface According to transmission, the microprocessor (7) connection LCD MODULE (8) simultaneously passes through the SOC that LCD MODULE (8) shows battery Value.

2. the battery SOC estimation device according to claim 1 based on CAN bus, it is characterised in that：The voltage detecting Module (2) includes voltage sensor, and voltage sensor is connected between the positive and negative anodes busbar of power battery pack (1), voltage sensor The output terminal of device is connected with AD conversion module；

The current detection module (3) includes current sensor, and current sensor is serially connected with the positive electrode bus of power battery pack (1) On, the output terminal of current sensor is connected with AD conversion module；

The temperature detecting module (4) includes temperature sensor, and temperature sensor is affixed on the surface of power battery pack (1), temperature The output terminal of sensor is connected with AD conversion module；

The internal resistance measurement module (5) includes internal resistance measurement instrument, and the positive and negative anodes that internal resistance measurement instrument is serially connected with power battery pack (1) are female On line, the output terminal of internal resistance measurement instrument is connected with AD conversion module.