Dynamic analysis of a novel electromagnetic transducer for hybrid vehicle and experimental verification

Abstract: This thesis presents the results of the work carried out on the dynamic analysis and experimental performance measurements of a novel concept of electromagnetic system for hybrid vehicle powertrains.The main focus of this work is to present how this novel electromagnetic system can be operated in a hybrid vehicle and to show how a prototype of this system has succesfully been operated in a laboratory set-up.Research on hybrid vehicle powertrains is encouraged by the increasing popularity of these vehicles. There is a large variety of solutions for hybrid vehicle powertrains. At the Royal Institute of Technology (KTH), Stockholm, Sweden, a novel machine concept intended for hybrid vehicle powertrains has been developed. It consists of two electrical machines built together in one unit. It is called the Four Quadrant energy Transducer (4QT) and is intended to link a combustion engine to the transmission in a hybrid vehicle, and by an apropriate control to improve the vehicle efficiency in comparison to a conventional vehicle of similar size and performance.The research project on the 4QT system has been carried out by a research team, since 1995. It evolved from early machine study and vehicle simulation, to prototype design and manufacturing. The work presented in this thesis completes the previously published works on the 4QT, with dynamic simulations of a 4QT equipped vehicle and the experimental testing of the prototype machines.An experimental setup has been built in order to test the performance of the prototype machines. The control of the machines and its experimental implementation are presented. The experimental setup is controlled to simulate drive cycle conditions, in order to measure efficiency of the prototype machines. Dynamic simulations of a vehicle equipped with a 4QT have been carried out to analyse the powertrain behaviour under transient conditions.It is shown that it is possible to control the 4QT prototype and operate it within its full operating range. Results of the efficiency measurements show that the efficiencies are slightly lower than expected, probably due to an underestimation of the stray load losses. This gives room for further research and improvements in the design of the prototype machines. Transient simulations underline the importance of the control strategy and dimensioning of the powertrain elements to avoid excessive stress on the vehicle.