Performance research and optimization of vehicle-mounted claw-pole generator based on 3D electromagnetic field and circuit coupling modeling

In order to solving the problems such as low output voltage and current performance of traditional claw-pole generators, the performance research and optimization of vehicle-mounted claw-pole generator have been done. Based on the prototype data, the magnetic field model of the generator is built with 3D FEM, and the circuit model is built with SPICE. According to the parameter change curve in the traditional generator operation, the mathematical model is modified in the simulation, the results show the reliability of this built model. The simulation of this model without optimization under no-load and load are compared. From the change curve of the magnetic density at each point of the rotor, the geometric parameters in the claw pole model are optimized to explore the change of the induced voltage, and the voltage of the model with optimization is obtained. The prototype is produced and tested, the data is analyzed, the optimized model and the prototype can effectively improve the induced voltage and output current. The application of the three-dimensional field-circuit coupling in the claw-pole generator is verified.

I. Introduction

Claw-pole generators are used in the daily automotive industry due to their simplicity and low cost [1]. In recent years, along with industrial applications, strengthening research and performance upgrades, the method of rotor structure optimization has received more and more attention in claw-pole generators. Compared with stator shape optimization, it has the advantages of small modification range and magnetic field concentration. The rotor is equipped with a toroidal magnetic field coil, and the internal magnetic flux is statically distributed in three dimensions [2]. The traditional modeling analysis ignores the three-dimensional field-circuit coupling, The magnetic field generated by the rotor winding will saturate the local iron core of the traditional rotor claw pole, The eddy current loss caused by the rotation of the rotor causes the temperature to rise under the condition of poor internal ventilation [3]. High temperature superconducting static magnetic field windings are prone to quench [4], and interpole permanent magnets are installed between the rotor claw poles, which brings about the problem of cost increase [5]. According to the obtained original data and parameter change curve, using simulation software, the finite element method is used to model and electromagnetically simulate the claw-pole motor [6]. Starting from the rotor core, magnetic field leakage and magnetic saturation are the main factors of low efficiency. By analyzing the three-dimensional magnetic density inside the claw pole, it is observed whether the magnetic saturation in the rotor core is not enough. The pole shape is redesigned to make better use of the internal space structure and rotor magnetic flux to explore the impact on the output performance [1] [7].