Page 32 - PEN eBook February 2024

TEST & MEASUREMENT TEST & MEASUREMENT

Figure 1: V-cycle development flow

software and hardware design, model- and software- BIL REAL-TIME SIMULATION
CATARC Enhances in-the-loop verification, HIL testing and real-vehicle PLATFORM
testing. Notably, HIL testing of the controller plays
In response to these challenges, CATARC employs
a key role in this process. The HIL test platform
Battery Testing establishes a virtual operating environment for the simulation and testing to introduce a comprehensive
controller, verifying its functions by providing specific
set of BIL test solutions. This platform effectively
narrows the gap between HIL tests and real-vehicle
input signals and monitoring corresponding output
with Innovative BIL signals. road and field tests, minimizing the demands for field,
environment and vehicle requirements. A comparison
While the traditional signal-level HIL test is effective
of the different test methods is shown in Table 1.
Simulation for verifying BMS functional strategies, it falls short Test Scene Test Test
of verifying battery pack performance. Real-EV road
and field tests offer the most realistic assessment of
battery pack performance; however, they are limited Methodology Realism Richness Flexibility Efficiency Cost
By Jian Ding and Kexin Yin, engineers in the electronic control department at CATARC by narrow test condition coverage and stringent Road Test High Low Low Low High
ISO 26262 functional safety requirements. In addition, Relatively
conducting real-EV tests in specific environments, BIL Test High High High High Middle
While traditional signal-level hardware-in-the-loop international standard improving the safety of electrical such as extremely high or low temperatures, demands Table 1: Comparison of the road and BIL test methods
(HIL) tests effectively verify battery management and electronic systems. higher environmental requirements.
system (BMS) functional strategies, they fail to validate
battery pack performance effectively. Real-vehicle GROWING COMPLEXITY OF BATTERY
road and field tests provide realistic insights, but their DESIGN
limitations in test condition coverage and stringent Across various countries, research on EVs consistently
requirements pose challenges. This case study explains identifies the battery as the most problematic
how the China Automotive Technology and Research component. Ensuring battery system safety involves
Center (CATARC) is pioneering advancements in battery considerations of battery-cell characteristics, module
testing by implementing a battery-in-the-loop (BIL) design, pack structure, exhaust design and the
simulation system. dominant role of the BMS. This system is increasingly
regarded as the core technology for EV makers, as
EVOLVING CHINESE AUTOMOTIVE evidenced by the surge in core intellectual-property
MARKET rights related to batteries.
The development of the automobile industry in China
is at a pivotal stage, presenting opportunities, risks and The typical approach in developing and testing EV
challenges. Electric vehicles hold substantial potential controllers involves adopting the V-cycle development
to enhance economic and industrial competitiveness, process, as shown in Figure 1. This process enhances
attracting investments in major markets. To address development efficiency, mitigates risks and reduces
functional safety concerns in automotive software, the overall workload. It efficiently progresses through
the industry has established ISO 26262, a critical system requirements, functional requirements, Figure 2: BIL test system framework

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