Understanding how vehicles use and distribute energy is crucial for electric vehicle development and certification. Electrical powertrain, including motors and inverters, heating, air conditioning, infotainment, and other sub systems all consume energy that is being supplied by the battery pack. Any energy usage or inefficiency can result in a shorter range of the vehicle. By mapping out the energy usage of all the subcomponents, automotive engineers can start to make decisions about vehicle control, and component selection to maximize the range of the vehicle. Vehicle manufacturers must make important decisions between weight, cost, range, and performance to make vehicles that have a desirable range for customers, and that meet the green energy requirements.
There are three main groups who are interested in vehicle energy consumption, certifying bodies, system engineers, and component engineers. Certifying bodies need accurate power measurements to give the electrical mile per gallon (MPGe) efficiency certification of a vehicle. This number allows consumers and governing bodies to make decisions. Vehicle and system level engineers need to understand how the different components and subsystems perform so they can optimize the range of a vehicle. This is not just for powertrain, but all the subsystems that are also consuming energy. Lastly component level engineers need to be able to look at where losses are occurring and how to minimize them.
These types of vehicle range tests require a standardized torque and speed profile so that it can be a true standardization between vehicle ranges. The profiles, often referred to as drive cycles (figure 1), are a profile of speed vs time. The drive cycles have different speeds, accelerations, and decelerations to simulate “city” and “highway” miles.
Sign in now access and download this full paper
Videos on Vehicle Energy Management and Range Testing
If you have any questions concerning Electric Power Testing, we are here to support you.
Mitch Marks is among HBK's many experts in electric machine and drivetrain testing. He is a Business Developer for Electrification at HBK - Hottinger, Brüel & Kjær with a Masters in electrical engineering. If you have any questions regarding measuring vehicle energy and power distribution, our products or applications, please get in touch with Mitch.