What are the specific details of the aging test equipment?

What are the specific details of the aging test equipment?

The following are more specific details of the lithium battery pack automatic aging test equipment:

Charging and discharging equipment

Power module:

This is one of the core components of the charging and discharging equipment, responsible for providing and regulating the electrical energy required for the charging and discharging process. It can output accurate current and voltage according to the set parameters to meet the testing requirements of lithium battery packs of different types and specifications. For example, for high-capacity and high-power lithium battery packs for electric vehicles, the power module needs to have a large output power, which may reach tens of kilowatts or even higher, to achieve fast and stable charging and discharging operations.

Advanced power electronics technology is usually used, such as high-performance power devices such as IGBT (insulated gate bipolar transistor) to achieve efficient power conversion and precise control. These devices have the advantages of fast switching speed and low on-resistance, which can effectively reduce the loss of electrical energy during the conversion process and improve the charging and discharging efficiency.

Charging and discharging control circuit:

It is mainly used to accurately set and control the charging and discharging mode, parameters, etc. It can realize the switching of multiple charging and discharging modes, such as constant current charging, constant voltage charging, constant current discharge, constant voltage discharge and various combination modes. For example, at the beginning of charging, it is set to constant current charging mode. When the battery voltage reaches a certain value, it can automatically switch to constant voltage charging mode. The whole process does not require manual intervention, and all are accurately executed by the control circuit according to the preset program.

It can set and adjust the parameters such as charging and discharging current and voltage with high precision. Its current control accuracy can reach ±0.1% or even higher, and the voltage control accuracy can reach about ±0.05%, ensuring that the charging and discharging process is strictly carried out according to the set value, thereby providing a reliable data basis for accurately evaluating the performance of lithium battery packs.

Charging interface and cable:

The design of the charging interface should match the interface specifications of the lithium battery pack to ensure good electrical connection. Common interface types include circular interface, rectangular interface, etc., and must comply with relevant industry standards, such as GB/T 20234 (China Electric Vehicle Conductive Charging Connection Device Standard).

Charging cables need to have good conductivity, insulation and mechanical strength. Generally, multi-strand copper core wires are used, and they are wrapped with high-quality insulating materials, such as polyvinyl chloride (PVC) or cross-linked polyethylene (XLPE). The cross-sectional area of ​​the cable should be reasonably selected according to the size of the charging and discharging current to avoid affecting the test results or causing safety hazards due to the heating of the cable during the charging and discharging process.

Temperature sensor:

It is used to monitor the temperature of the test environment in real time. Common temperature sensors include thermocouples and thermal resistors. Thermocouples have the advantages of fast response speed and wide measurement range, and can be used to measure a wide temperature range from low temperature to high temperature, such as -200℃ to 1600℃; thermal resistors are known for their high measurement accuracy, especially suitable for medium and low temperature range measurements, such as -200℃ to 800℃.

In the test equipment, temperature sensors are generally installed in multiple locations, such as the center, surroundings, top and bottom of the test environment, to fully and accurately obtain environmental temperature information, to ensure that the temperature control system can adjust the heating or cooling operation in time according to the actual temperature conditions, so that the ambient temperature is maintained within the set range.

Temperature controller:

It controls the heating element and the cooling element according to the temperature information fed back by the temperature sensor. The temperature controller has built-in advanced control algorithms, such as PID (proportional-integral-derivative) control algorithms, which can accurately adjust the working state of the heating or cooling elements according to the size and change trend of the temperature deviation to achieve fast and accurate control of the ambient temperature.

Different temperature control modes can be set, such as constant temperature control, temperature gradient control, etc. For example, in the constant temperature control mode, the ambient temperature can be accurately maintained at a fixed value, such as 25℃±2℃; in the temperature gradient control mode, the ambient temperature can be dynamically controlled according to the set temperature change law, such as increasing or decreasing by 5℃ per hour.

Data acquisition system

Voltage acquisition module:

Responsible for collecting voltage data of lithium battery packs and each single cell. It uses high-precision voltage measurement chips or circuits, which can measure voltage ranges from a few volts to tens of volts or even higher. For example, for some lithium battery packs composed of multiple single cells, the total voltage may reach hundreds of volts, and the voltage acquisition module needs to be able to accurately measure such high voltage values.

The voltage acquisition accuracy can generally reach ±0.05% or even higher, ensuring that the collected voltage data truly reflects the actual voltage state of the battery. At the same time, in order to facilitate subsequent data analysis, the voltage acquisition module usually digitizes the collected voltage data and transmits it to the data storage and analysis equipment in the form of digital signals.

Current acquisition module:

It is used to collect the current data of the lithium battery pack during the charging and discharging process. It also uses a high-precision current measurement chip or circuit, and its measurement range can be adjusted as needed, generally covering the current range from a few milliamperes to thousands of amperes. For example, for lithium battery packs used in electric vehicles, thousands of amperes of current may appear during fast charging, and the current acquisition module needs to be able to accurately measure such large current values.

The current acquisition accuracy can also reach ±0.05% or even higher to ensure the accuracy of the collected current data. In addition, the current acquisition module will also digitize the collected current data and transmit it to the data storage and analysis equipment in the form of digital signals.

Temperature acquisition module:

It mainly collects the temperature data of the test environment where the lithium battery pack is located, as well as the temperature data of the battery itself (if the battery has a built-in temperature sensor). It uses the working principle of the temperature sensor in the temperature control system, and uses sensors such as thermocouples or thermal resistors to measure temperature.

The temperature acquisition accuracy can generally reach ±0.05%, ensuring that the collected temperature data can accurately reflect the actual temperature conditions. The collected temperature data will also be digitized and transmitted to the data storage and analysis device in the form of digital signals.

Data storage device:

Used to store various collected data, such as voltage, current, temperature, etc. Common data storage devices include hard disks, solid-state drives (SSDs), etc. Hard disks have the advantages of large capacity and low cost, and are suitable for storing large amounts of long-term test data; solid-state drives have the advantages of fast read and write speeds and good seismic resistance, and are more suitable for storing data that requires frequent reading and writing, such as data collected in real time during aging tests.

Data storage devices generally store data at certain time intervals or data volumes, such as storing data every 10 minutes, or when the collected data volume reaches a certain scale (such as 1,000). At the same time, in order to facilitate subsequent data analysis, the stored data is generally classified and sorted, and archived according to different test items, battery numbers, etc.

Data analysis software:

Analyze the various data stored in the data storage device. It can realize a variety of data analysis functions, such as drawing curves of voltage, current, temperature, etc. changing over time, calculating key indicators such as capacity decay rate and internal resistance change rate, and performing voltage consistency analysis.

Data analysis software usually has a user-friendly interface, which is convenient for operators to view, analyze and process data. For example, you can view the data of a battery pack at different stages by simply clicking the mouse, or quickly calculate the required analysis indicators by entering specific parameters.