The Analysis And Calculation Of Equivalent Magnetic Circuit Network On Hybrid Claw-Pole Alternator

The Hybrid claw-pole alternators have magnetic fields contributed by permanent magnet as well as excitation coil, and the advantages are high efficiency ,have good low-speed characteristics, excitation adjustable and high flux densities. For the reason of complex claw-pole construction and 3-D magnetic field distributions, there is lack of the research on the alternators.The Equivalent Magnet Circuit Network (EMCN) Method is based on combination between conventional MEC and FEM. The conventional Magnet Circuit Method transfer the field in electrical machine into magnet circuit to analyze and calculate the parameters and performance of electrical machine. The EMCN splits the magnet circuit into many elements according to the different flux distribution in the machine. The flux in each element can be considered to be even. The EMCN model is set up by use of flux-tube method. In this method, the segment in which the flux density is relatively even is considered to be an element, the permeance of each element can be calculated by use of conventional method. Finally the permeance network can be set up by connecting each node with permeances, then the parameters and performance can be obtained. EMCN can transfer the area in machine into several elements, each node and mesh are fixed and irrelevant to rotor rotation. Only the values of permeances are related to motor rotation, but all the relations of the permeances are fixed. So, only the permeance value should be calculated again when the dynamic performance is considered. There are few elements in EMCN, the mesh time can be reduced greatly and calculation time is more less than FEM time. EMCN considers the influence of the different flux distributions and leakage flux in alternator. The calculation accuracy is greater than conventional MEC. EMCN possess advantage of conventional MEC and FEM. So this method has many advantages in calculating special field such as 3D field and highly saturated field. The calculation results meet the requirements of engineering.This paper analyzes , models and calculates a six-pair poles hybrid claw-pole alternator. The calculation results are compared with the results of FEM. The comparison shows that this method meets the accuracy needs, and reduces the calculation time greatly.