From the principles of electromechanical energy conversion and electromagnetic torque generation, our study evaluated the mathematical model of the electromagnetic torque and the vector control method of motors. An analysis of motor types indicates that the electromechanical energy conversion component is interchangeable. Three distinct types of motor structures, namely DC, induction, and synchronous, are possible, all three being commonly used in pure electric vehicles. For each motor type, simulation models were developed using Modelica, a modeling language for object-oriented multi-domain physical system. A test model of each motor type was configured in the MWorks simulation platform. With a representative motor, specifically the permanent-magnet DC motor, the asynchronous induction motor, and the permanent-magnet synchronous motor, mechanical properties were simulated and analyzed. The simulation results show that the characteristics of each motor model are consistent with the theoretical and engineering performance of the representative motor. Therefore, modeling, motor control, and performance testing of a unified multi-pole-field motor, which is used in pure electric vehicles, have been achieved.