TREMEC – System Model of a high performance EV Powertrain

Contact:      Leroy De Ruijsscher – leroy.deruijsscher@tremec.com
Registratie:  De student kan zich aanmelden via jobs.be@tremec.com t.a.v. Yana Feyers.

Probleemstelling

In recent years, the global goal to reduce greenhouse gas emissions has pushed the automotive industry to transition from ICE (Internal Combustion Engine) vehicles to EV’s (Electric Vehicles). Even though the function of the powertrain (providing power to the wheels) remains the same, the involved technology is completely different. As much as for ICE vehicles, key factors for an EV continue are driving range, comfort and performance. These translate directly into powertrain requirements in terms of: efficiency, controllability, thermal management, structural integrity, … In a high-performance application, the powertrain is operated to the limits of its capabilities. To allow this, an in-depth knowledge of all systems involved and their interactions is required. In an early stage of the development, system models are established to evaluate a system’s behaviour in several operating conditions allowing system design decisions to be taken early on.

Doelstellingen

The goal of this thesis/research is to establish an approach and model to accurately characterize the system behaviour of a high performance EV, with focus on the Electric Drive Unit (EDU). The model should cover all interfaces between the subsystems of the powertrain, these being: battery, inverter and motor. With this model, system effects of certain design choices (e.g. battery properties, cable length, DC link capacitance of inverter, motor inductance, …) are investigated. System effects under investigation include (but are not limited to): DC voltage ripple, AC current ripple, system efficiency/losses, controllability, … In conclusion, critical design choices and parameters are discussed, their impact on the system and their interaction with other subsystems.

Approach: A literature study is performed on EV powertrain modelling techniques: which components are used and what level of detail is sufficient? It’s important to do this exercise with high performance applications in mind. As a result of the study, a good understanding of the used components and their parameters is available. An initial assessment is made about how key design parameters are influencing system behaviour. Building the model is based on the findings of the literature study. Preferably a 1-D simulation software package is used (e.g. Simulink/Simscape, SimulationX, …) to create the model in which a TREMEC EDU is combined with a HV battery. Once available, tests can be performed on system and/or subsystem level to validate the outcome. As next and final step, with sufficient confidence, a sensitivity study is conducted to identify the key design parameters, which can translate into a set of designrules and suggestions on system improvement where possible.