An Interactive Traction Motors Design and Selection Software
Use of electric motors in vehicle traction, in fact, predates the internal combustion engines (ICEs). Electric vehicles powered by dc motors were known as far back as 1890. Compared with vehicles powered by ICEs, the main drawback of the early electric vehicles was, and still is, their limited range and long recharging time. To overcome this, in recent years, developments have been focused on hybrid electrical vehicles (HEVs) combining two sources of energy: an ICE of a conventional vehicle and an electric motor (or motors). Such a hybrid vehicle enables the driver (or the vehicle computerised energy management system) to decide which source of power is appropriate for a particular journey.
Drive Trains for HEVs are of course more complex than both conventional ICEs and totally electric vehicles. Design of HEVs, therefore, encompasses several technologies and the vehicle designer cannot be expected to be an expert in all related fields. In particular, it is recognised that vehicle designers may not be familiar with electric drive systems. The work reported here aims to provide a design tool to enable decisions to be made on type and feasibility of traction motors to meet specific traction requirements.
In the first part of the software described in this thesis normalized curves, giving theoretically available force density values for different cooling arrangements, are utilised, after adopting piecewise linear approximations, to provide the vehicle designer with a quick answer to whether or not drive requirements can be met within a specified space envelope. Once the requirements are deemed feasible, the user can progress to the second part of the programme in which detailed design work for a selected drive topology is carried out. Thereafter, the user can export drive details into a number of commercially available CAE packages to perform further investigations (e.g. dynamic performance).
Due to time constraints, only induction motor systems are fully developed in the reported work. However, the design of the software allows for modules relating to conventional dc, reluctance and brushless dc drives to be added at a later stage.
Internal Combustion Engines (ICEs)
· Electric Motors (EMs)
Hybrid Electric Vehicles (HEVs)