Design and Implementation of a Modular Test Bed Platform for Hardware-In-the-Loop Simulation of Electric Vehicles

Abstract

Over the course of the last decade, electric vehicles have seen explosive growth and interest with public adoption and shifting research and development priorities by original equipment manufacturers towards these new powertrains. However, the development of electric vehicles remain costly due to new technologies being implemented in the vehicle with the final cost ultimately being passed down to consumers. This method of developing new products where the price does not justify the product in the eyes of consumers hinders the adoption of the next generation of environmentally friendly vehicles.

To verify electric vehicle drivetrain platforms and software models, test beds with specific capability to simulate the entire vehicle are required. Currently, an abundance of valuable engineering resources are dedicated to creating full-scale test beds and full- sized vehicles for testing. Only then, at this stage in the development cycle, are drivetrain tests conducted outside of simulation models. Getting to this first level of functional testing requires using valuable time waiting for components to be designed, manufactured, validated, and installed before the system can be tested. The full-scale vehicle test bed becomes expensive, consumes a lot of space, and cannot be reconfigured easily without changing key components.

Therefore, this thesis presents a systematic approach to down-scaling full-size electric vehicles’ parameters and environmental conditions to a level that can be handled by a small-scale hardware-in-the-loop simulation test bed. The method for taking the results obtained from the test bed and scaling them back up to the full-size vehicle level are also examined for completion. The hardware-in-the-loop test bed is realized using a twoelectric machine system. The electric machine responsible for the electric vehicle propulsion is the traction motor and is tasked with maintaining the vehicle speed. The other electric machine, directly coupled to the first machine, is controlled by the simulation environment. This machine is the load motor which emulates the vehicle operating environment including the forces acting on the vehicle. This motor also compensates for all losses experienced by the actual hardware setup.

A detailed explanation of the entire hardware-in-the-loop setup is discussed with specific details relevant to the system design. The modularity of the system, allowing each block of the setup to be easily replaced, and making the test bed highly re-configurable, is also discussed in detail.