In the era of Electric Vehicles (EVs), range is a critical factor for market success. To mitigate range anxiety, Original Equipment Manufacturers (OEMs) are equipping vehicles with larger battery packs. Unlike internal combustion engine (ICE) vehicles, where fuel economy can be determined with a single legislative cycle run, EVs require a full battery discharge to calculate their range. These tests typically take around 10 hours, and this time increases as battery pack sizes grow. A shortened testing cycle has been developed that reduces the testing time to approximately 4-5 hours, leading to significant savings in time, effort, and cost. The shortened cycle consists of three phases: Dynamic Segment1, Constant Speed, and Dynamic Segment2.
Despite variations in battery size and powertrain configurations, the testing duration remains consistent. A key challenge in actual testing is accurately determining the start and end points of Dynamic Segment 2 (DS2), which is an iterative process that requires more time, effort and cost. Simulation offers a solution to this challenge. It can generate a shortened cycle that adapts to changes in both hardware and powertrain, which can then be used in actual testing. The start and end of DS2 are determined based on the battery's state of charge (SOC), and the simulation directly provides the required velocity traces. The generated shortened cycle can be applied to the dynamometer for real-world testing. The energy consumption of the two dynamic segments is weighted to calculate the pure electric range, which matches the range obtained from a full test cycle. This approach and methodology are applicable to all legal test cycles, offering significant time savings, especially for the NEDC cycle.
The shortened cycle test not only accelerates the testing process but also optimizes resource usage by conserving energy, lowering operational costs, enhancing manpower productivity, and improving test bench availability.