Energy Efficiency of a Diesel-Electric MobileWorking Machine
Immonen, Paula (2013-06-06)
Väitöskirja
Immonen, Paula
06.06.2013
Lappeenranta University of Technology
Acta Universitatis Lappeenrantaensis
Julkaisun pysyvä osoite on
https://urn.fi/URN:ISBN:978-952-265-415-1
https://urn.fi/URN:ISBN:978-952-265-415-1
Tiivistelmä
The power demand of many mobile working machines such as mine loaders, straddle carriers
and harvesters varies significantly during operation, and typically, the average power
demand of a working machine is considerably lower than the demand for maximum power.
Consequently, for most of the time, the diesel engine of a working machine operates at a poor
efficiency far from its optimum efficiency range. However, the energy efficiency of dieseldriven
working machines can be improved by electric hybridization. This way, the diesel
engine can be dimensioned to operate within its optimum efficiency range, and the electric
drive with its energy storages responds to changes in machine loading. A hybrid working
machine can be implemented in many ways either as a parallel hybrid, a series hybrid or a
combination of these two. The energy efficiency of hybrid working machines can be further
enhanced by energy recovery and reuse.
This doctoral thesis introduces the component models required in the simulation model of a
working machine. Component efficiency maps are applied to the modelling; the efficiency
maps for electrical machines are determined analytically in the whole torque–rotational speed
plane based on the electricalmachine parameters. Furthermore, the thesis provides simulation
models for parallel, series and parallel-series hybrid working machines. With these simulation
models, the energy consumption of the working machine can be analysed. In addition,
the hybridization process is introduced and described.
The thesis provides a case example of the hybridization and dimensioning process of a working
machine, starting from the work cycle of the machine. The selection and dimensioning of the hybrid system have a significant impact on the energy consumption of a hybrid working
machine. The thesis compares the energy consumption of a working machine implemented
by three different hybrid systems (parallel, series and parallel-series) and with different component
dimensions. The payback time of a hybrid working machine and the energy storage
lifetime are also estimated in the study.
and harvesters varies significantly during operation, and typically, the average power
demand of a working machine is considerably lower than the demand for maximum power.
Consequently, for most of the time, the diesel engine of a working machine operates at a poor
efficiency far from its optimum efficiency range. However, the energy efficiency of dieseldriven
working machines can be improved by electric hybridization. This way, the diesel
engine can be dimensioned to operate within its optimum efficiency range, and the electric
drive with its energy storages responds to changes in machine loading. A hybrid working
machine can be implemented in many ways either as a parallel hybrid, a series hybrid or a
combination of these two. The energy efficiency of hybrid working machines can be further
enhanced by energy recovery and reuse.
This doctoral thesis introduces the component models required in the simulation model of a
working machine. Component efficiency maps are applied to the modelling; the efficiency
maps for electrical machines are determined analytically in the whole torque–rotational speed
plane based on the electricalmachine parameters. Furthermore, the thesis provides simulation
models for parallel, series and parallel-series hybrid working machines. With these simulation
models, the energy consumption of the working machine can be analysed. In addition,
the hybridization process is introduced and described.
The thesis provides a case example of the hybridization and dimensioning process of a working
machine, starting from the work cycle of the machine. The selection and dimensioning of the hybrid system have a significant impact on the energy consumption of a hybrid working
machine. The thesis compares the energy consumption of a working machine implemented
by three different hybrid systems (parallel, series and parallel-series) and with different component
dimensions. The payback time of a hybrid working machine and the energy storage
lifetime are also estimated in the study.
Kokoelmat
- Väitöskirjat [1025]