| The electric vehicle traction system is not working during battery charging, on the basis of adding less components or without adding components, make the traction systems connect to the grid and utilize the power converter of traction system as controllable rectifier for battery charging, meanwhile utilize the motor winding as filter inductor or isolated transformer, this is called intergrated charger. In terms of the electric vehicle control system, Z-source converter could overcome the defeats of tradictional converter and compose a single stage controllable converter which could adjust the voltage of DC bus. This thesis makes a preliminary study of the integrated charger on the basis of the Z-source converter.Firstly, this thesis will introduce the Z-source converter and analyze its operating principle and control method in detail, then compare two allocation methods of the Z-source shoot-through time. In order to make the system achieve unity power factor charging, this thesis determines the proper range of Z-source capacitor voltage and give a example on the basis of experimetal parameters.Secondly, the winding integrated methods is studied in this thesis base on the Z-source converter. In order to make rotor hold still during battery charging, two non-isolated integrated methods of machine winding are proposed and compared. For the isolated integrated charger, the operating principle and prerequisite are studied, a control method for battery charging is proposed base on its mathematical model, the whole system will be verified by simulation results.Thirdly, the whole system of Z-source charger is designed, then the hardware circuits and the software control program are introduced in detail. In order to verify system feasibility, this Z-source charger will charge the resistance and the battery.Finally, the sum-up of the Z-source integrated charger is made and some ideas about the Z-source integrated charger are proposed. |
