Matti Liukkonen

Hardware-in-the-loop verification environment for heavy-duty hybrid electric vehicles

This paper presents an implementation of a versatile hardware-in-the-loop verification environment for heavy-duty hybrid electric vehicle (HEV) control software development. The verification environment is located at university facilities, and it consists of full-scale HEV systems that can be loaded with either an electric motor dynamometer or a programmable chassis dynamometer. Model-based software development tools and rapid control prototyping hardware are used to control the test bench hardware and to develop and execute control software. The verification environment can also be used e.g. to measure the efficiency of electric traction motors, power electronic converters, energy storages, and hydraulic pumps.

Validation of quasi-static series hybrid electric vehicle simulation model

This paper presents validation measurements of a series hybrid electric vehicle (SHEV) drive line with an ultracapacitor energy buffer. The backward functional quasi-static power transfer plant models in SHEV are discussed and compared against validation measurements. The full power measurement equipment and equipment under tests (EUT) are presented. A traditional road cycle is used to imitate duty vehicles loading in the plant models validation tests. Finally, an energy management algorithm and its behavior are presented, and results are concluded.

Modeling of multiport DC busses in power-electronic systems

This paper deals with dynamic modeling of multi-port DC busses, which are increasingly applied in various DC-power distribution systems, such as hybrid powertrains and DC microgrids. Parasitic impedances of long DC cabling together with distributed DC capacitors introduce a potential risk of small-signal instabilities in the DC bus, if resonance frequencies of the bus appear below (or around) switching frequencies of power-electronic converters. In order to predict the resonance behavior of the bus, a systematic approach for dynamic modeling of the DC bus in power-electronic systems is presented. The DC-bus model is validated by means of experiments. Furthermore, application of the model in small-signal analysis and time-domain simulations is illustrated.

Design of an energy management scheme for a series-hybrid powertrain

This study presents a design method for an energy management scheme of a series-hybrid powertrain. Different drive line topologies are briefly introduced, and their advantages and disadvantages discussed. Furthermore, an systematic energetic macroscopic representation (EMR) is used to introduce an example of a fuel cell (FC) series-hybrid electric vehicle (SHEV) drive line, and its energy management in more detail. As a result, the study illustrates a design space of the powertrain, which can be derived based on the proposed energy management and dimensioning rules. Besides, feasibility of an EMR for the design, as well as the documentation of an energy management scheme is described.

Comparison of different buffering topologies in FC-hybrid non-road mobile machineries

This paper presents powertrain comparison for fuel cell hybrid non-road mobile machinery. The objective of this study is to investigate the feasibility of different fuel cell hybrid powertrain topologies. This study concentrates on hybrid powertrain topologies which are generated from the fuel cell source output to loading inverters inputs. The compared features of different powertrains are efficiency, weight, size, cost and lifetime costs, as well as, benefits and disadvantages. The study considers fuel cell hybrid topologies with different active and passive connections of a battery pack, an ultracapacitor pack or the both. The comparison of different powertrain topologies requires a validated simulation tool, specific power control algorithms for each topology, knowledge of the target application and several iteration rounds for simulations.

Design of an energy management scheme for a series–hybrid powertrain in heavy–duty vehicle applications

This paper presents a systematic and efficient design method for an energy management scheme of a series–hybrid powertrain. Different fuel–cell powertrain topologies are briefly introduced and their advantages as well as disadvantages discussed in perspective of heavy–duty vehicle applications. Plant models and energy management algorithms for a modern powertrain sizing approach are described with mathematical descriptions and aid of an energetic macroscopic representation, because of a need for detailed alternative powertrain design descriptions to educate new engineers to electrify vehicle systems in upcoming decades. Therefore, the paper illustrates a design space of the powertrain with a fuel–cell system buffered by passive battery and active ultracapacitor packs. Furthermore, a time–domain simulation and input parameter sensitivity analysis of the energy management scheme is presented, specifically - for interest of practising powertrain engineers aiming for series–hybrid powertrain adoption in demanding applications.

Sensitivity analysis for the design of an energy management scheme of supercapacitor buffering in a regulated DC bus

This paper constitutes a solid connection between theory and practice for electrical quantities for the design of supercapacitor buffering in regulated DC-bus systems. Transparently validated theory is proposed to be used for decision making that bases on estimates of sensitivity indices, expanded uncertainty intervals, and the Monte-Carlo method. This approach can be used for engineering of various DC-power distribution systems that are increasingly applied in hybrid powertrains of electric vehicles and DC microgrids. Results conclude a clear connection between theory and practice, and a well established approach with examples of its usage can be easily adopted.