MCE MODELS - Development of marginal conversion efficiency models for Powertrade

Powertrade is a distributed model based optimization methodology under development at AB Volvo that intends to include all energy consumers and energy storages in a single vehicle energy management strategy. The objective is to maximize global efficiency and thereby lower the total net energy losses that contribute to the total fuel cost. The scope of the project that this report is a part of is to develop Powertrade for demonstration in a parallel-hybrid city bus. Viktoria Swedish ICT has during the project assisted AB Volvo by modeling marginal conversion efficiency for the components that are included in the current version of Powertrade. This report describes the development of these models and the reasoning behind them. Models were developed for the following components; internal combustion engine, electric machine, air conditioning system, DC/DC converter, 600-volt battery and 24-volt battery. The suitability of the models differed profoundly, mainly due to that some models were based on unsatisfactory measurement data, but also since the components differ in nature and complexity. The overall conclusion is that all MCE-models but AC and 24-volt are sufficient for verifying the Powertrade’s ability to handle different variants of vehicles and to indicate the effort required for a production ready implementation. Significant model refinement is however needed if for example the concept’s savings potential is to be evaluated. Powertrade