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—— Overview
In the power system of electric vehicles, the power battery is always an important part of technology. As an important link between battery packs, vehicle systems and motors, BMS controllers must undergo rigorous testing for their functional reliability and safety.
The BMS controller includes two parts: the battery control unit BMC and the battery monitoring unit CMC. The BMS function test will test the two control units individually and jointly. It can simulate and collect the battery cell voltage and temperature to complete the BMS and the sub-board (CMC). ) Between functional tests.
—— Main Function
• BMS function test:
※ SOC estimation, SOH estimation, power prediction;
※ Active and passive balance function, maximum voltage detection during the balance process, fault detection;
※ Same SOC verification, balanced current verification;
※ Voltage sampling function, current sampling function, temperature sampling function test;
※ AC charging test, DC charging test, etc.;
※ Test the safety-related algorithms of the BMS, such as monomer undervoltage and overvoltage, overcurrent, temperature too high or too low, open circuit and short circuit;
※ Verify the connection time of the monomer, verify the insulation detection of the BMS, etc.
• Battery pack system integration test:
※ Communication protocols such as CAN, LIN and SENT within BMS;
※ Synchronous response test of CMC CAN signal;
※ BMS system (BMC+CMC) network management, sleep wake-up response and other functional tests;
※ BMS system (BMC+CMC) quiescent current consumption evaluation, low-power state evaluation.
• Functional safety test of battery pack system:
※ Single battery short-circuit fault injection test;
※ Temperature sensor short circuit fault injection test;
※ Temperature sensor open circuit fault injection test;
※ Battery cell sampling line short-circuit fault injection test;
※ Battery cell sampling line open circuit fault injection test.
—— BMS HIL System Framework
• Hardware platform
※ NI PXI real-time simulation platform
※ Fault injection unit
※ Integrated signal management unit
※ Wire break test box
※ Programmable power supply
※ Power distribution unit
※ Host computer system
※ Battery cell simulation board
※ High voltage simulation system
※ CAN communication system
• PC software
※ Test management software
※ Automatic test software
※ Fault injection software
• Real-time simulation model
※ Electric car model
※ Lithium-ion power battery model
※ Test model |
BMS-HIL hardware structure
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—— System Solutions
Option A: BMS level test
The test principle is shown in the figure above. The BMS main module BMU and the BMS slave module CMU are integrated into the test system. The battery cell simulation board simulates the battery cell voltage and current; the resistance simulation board simulates the cell temperature; the high voltage simulation box simulates high voltage up and down. Power, pre-charge relay control, high-voltage fault simulation functions; at the same time, IO channels are used to simulate switches, sensors and collect the output of the BMS controller.
Option B: BMU level test
This test program only tests the BMS main control board, and does not require the slave control board, battery cell simulation board, and battery temperature simulation board. The slave control board is simulated by CAN communication, LIN communication, SENT signal, etc. The rest of the test plan is the same as the BMS level test.
—— BMS HIL Application Field
• Simulation of battery modules or cells;
• BMS balance, insulation and SOC estimation algorithm verification;
• BMS power on and off, high voltage fault diagnosis and verification;
• BMS charge and discharge, high voltage safety test;
• Communication and function verification based on actual vehicle conditions.
—— Typical Case
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