Conception d'un convertisseur électronique de courant continu à fréquence de commutation adaptative et commutation douce pour l'entraînement d'une voiture électrique

Abstract

The following document presents the steps performed to develop a 60kW DC power electronics converter to be integrated in the electronic drive manufactured by TM4 inc. for electric vehicles. Design steps are described and results obtained with the prototype that was built and tested are discussed. The main objective of the project was to reduce the cost of the converter currently used and to maintain the level of performance (97% efficiency at maximum power) for the same range of operation. The new converter had to operate from 220 to 400V DC input voltage and deliver 250 to 400V output voltage at maximum power (60kW). The literature review and the topology chosen for the new converter were done taking into consideration the importance of minimal modifications on the present converter. Thus, the new solution could be rapidly incorporated in a commercial product. For ex ample , the IGBTs modules were kept the same. The output bank capacitor was identified as the best target for cost reduction. In order to lower the output capacitance value, the output voltage regulation speed had to be accelerated. To do so, the value of input inductors was lowered and an analog current control circuit was designed. The selected topology is a three-interleaved IGBT leg converter associated with passive components performing soft switching. An original control method featuring adaptive variable switching frequency was designed in order to reach any point of the working range rapidly. The results presented here show that the output voltage regulation speed was the same on the prototype as on the one expected from the simulations and could reduce the output capacitor size to 20% of its CUITent value. Moreover, the measured efficiency of prototype reached 97% at nominal and maximum output power for output voltage of 250V. Efficiency at 400V of output voltage cou Id have been improved and a few quickly achievable solutions are suggested.

Date	4 Jan 2011
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Kamal Al-Haddad (Supervisor)