Improving the Quality and Safety of BMS

Zero carbon emission has vastly become a worldwide trend as the popularity of electric vehicles (EV) begins to grow; the battery is being the key component. The performance and safety of battery packs is critical to the EV; its core battery management system (BMS) needs to be thoroughly verified to ensure the battery’s safety.

▲ Chroma 8710 EV / Bus BMS ATS

Chroma 8710 BMS ATS provides battery cell voltage and temperature sensor simulation for battery management system; furthermore, it offers applications suitable for testing the UUT (unit under test) to reduce the problems when performing the tests. The inspection functions equipped by the system include:

  1. The BMS circuit designed power conversion circuit converts the starting battery voltage to the power required by digital circuit. It is necessary to confirm the power status to make sure that the control circuit works stably.
  2. Measurement accuracy is required when using high voltage to measure the battery pack total voltage. This voltage is also one of the judgment criteria for enabling insulation resistance. The inspection of insulation resistance is critical to safety requires verification. Besides supporting the verification, the best way is to perform calibration first and verification later.
  3. The high/low side drive circuit controlling the high voltage relay is also one of the vital items for verification. When an error occurs, if the high/low side gate drive circuit is not active to disconnect the charge and discharge circuit, it could cause safety problem and result in burning the electric vehicle. Therefore, it is necessary to check if the high/low side drive circuit is running normally under all kinds of conditions.

Chroma has in-depth research on battery management system that makes the 8710 BMS Functional ATS capable of fulfilling the above test requirements to perform a fully automated test procedure and long hour battery pack charging/discharging test.

Architecture Diagram of Chroma BMS

▲ Architecture Diagram of Chroma BMS

A battery management system usually comprises of a current sampling unit (CSU), a cell supervisory circuit (CSC), and a battery management unit (BMU) via CANbus to transmit signals and issue commands for operation. When verifying a battery management system, it is imperative to verify the cell status monitored by CSC as well as the active/passive balancing circuit and current consumption. For CSU, the validation of current sampling accuracy is essential as it may affect the battery SOC, SOH and overcurrent protection. As to the most complicate BMU that controls the entire system, it verifies the data returned from CSU and CSC.

Integrating with the test systems customized by Chroma can perform high quality functional verification on battery packs and battery management systems with provision of applications suitable for testing the UUT to reduce the trouble occurred during testing. For more information on the 8710 BMS ATS, please visit Chroma’s website below and list your needs and contact, we are happy to be of service.

More information please check on Chroma battery pack production line test

Implementation on Battery Management System Verification

Starting 2025, many countries around the world will begin a ban on the purchase of gasoline powered vehicles. As the policy grows closer to date, the development of the electric vehicle (EV) accelerates leading to a major breakthrough in battery technology. The battery plays an important role in improving the efficiency and safety of electric vehicles, and so does the battery management system (BMS).

▲ 87001 16CH Battery Cell Simulator

Best Tool for BMS Verification

The Chroma 87001 Battery Simulator is a powerful tool for verifying the battery management systems. It has voltage and current measurement and monitoring capabilities, providing 0~5V voltage regulation and 0~5A bidirectional current function per channel with simulation of voltage variation for 480 battery packs (2000V/4.2V) connected in series. The equipped output voltage control is convenient in testing upper and lower limits of battery operating range. It supports active and passive balancing circuit tests in 0~5A and 0~500mA two current ranges with measurement accuracy up to 0.02%F.S. For 0~5A range (power increase when paralleled), the accuracy is up to ±1mA with resolution up to 100uA that can meet the active balance design circuit test requirements. For 0~500mA range, the accuracy is ±100uA (0.02%F.S.) with resolution up to 10uA that can meet the passive balance design circuit test requirements. It is suitable for BMS circuit boards for measuring battery cell current consumption.

Significantly Reduce BMS Verification Costs

Certainly, the battery management system can also be used to verify the battery cell; however, it cannot maintain the same characteristics for repeated tests due to the influence of temperature, charging and discharging speeds, aging degree, and efficiency, etc. Moreover, setting up too many battery cells in the laboratory could raise safety concerns. In the past, the engineers connected several DC power supplies in series on their desk to test the cell supervision circuit (CSC) by manually adjusting the voltage and parameters, which took time and space, and the functions can be tested were limited. Using the Chroma 87001 Cell Simulator for testing became the better solution.

Easy-to-Integrate Devices with Complete Driver

The Chroma 87001 Batter Cell Simulator can be adapted to the battery management systems for electric vehicles, electric scooters, hand tools, and energy storage batteries. It has been applied to testbed for hardware in the loop (HIL) application by some system integrators. Chroma offers “easy-to-integrate device” and “complete driver” to give system integrators free of worries.

Chroma ATE transited its successful experience in the power electronics test industry to the battery test industry. After years of hard work and collaboration with major car manufacturers and battery pack factories, Chroma is capable of providing hardware devices and software tools to meet the test requirements through the know-how about the unit under test, reducing the trouble occurred during testing.

For more information on the 87001 Battery Simulator features and specifications, please visit Chroma’s website below and list your needs and contact, we are happy to be of service.  Model 87001 Battery Cell Simulator