Co-Simulation of Electrical and Propulsion Systems 2001-01-2533
One of the challenges of analyzing vehicular electrical systems is the co-dependence of the electrical system and the propulsion system. Even in traditional vehicles where the electrical power budget is very low, the electrical system analysis for macro power utilization over a drive cycle requires knowledge of the generator shaft rpm profile during the drive cycle. This co-dependence increases as the electrical power budget increases, and the integration of the two systems becomes complete when hybridization is chosen.
Last year at this conference, the authors presented a paper entitled “Dual Voltage Electrical System Simulations.” That paper established validation for a suite of electrical component models and demonstrated the ability to predict system performance both on a macro power flow (entire drive cycle) level and a detailed transient-event level. The techniques were applicable to 12V, 42V, dual voltage, and/or elevated voltage systems. The weakness of applying those electrical system analyses to real vehicles on drive cycles has already been noted. The required generator shaft rpm profile can only come from an analysis of the propulsion system.
ADVISOR® (ADvanced VehIcle SimulatOR) is a well established program from NREL (National Renewable Energy Laboratory) which analyzes the propulsion systems of both traditional and hybrid vehicles at the macro power flow level. As such, ADVISOR can provide the missing information required for electrical analyses. Likewise, ADVISOR could benefit from more detailed information concerning the load the electrical system places on the propulsion system. If this information transfer is done in a co-simulation environment, all of the necessary information can be passed bi-directionally between the propulsion system and the electrical system.
This paper details the development of a co-simulation environment between ADVISOR (based in MATLAB®/SIMULINK®) and Delphi Automotive's electrical system analysis in SABER®. The end goal of this work is a full integration of electrical analysis into the ADVISOR structure which is transparent to the end user.
This paper will demonstrate the ability to co-simulate the propulsion and electrical systems for traditional vehicles. Various load models (i.e. voltage dependent current sinks) will represent the power requirements of hardware. The paper will also provide a roadmap for extensions of this work into the hybrid vehicle realm.