Aiming at the problems of large excitation loss and low power generation efficiency of silicon rectifier generators and the unstable output voltage of permanent magnet (PM) generators, a hybrid excitation generator (HEG) with suspended brushless claw pole electrical excitation rotor (EER) and combined magnetic pole PM rotor is proposed in the present work. With only one fractional slot winding stator, the generator adopts PM field as the main magnetic field and electrical excitation field as the auxiliary magnetic field, which not only retains the advantages of high efficiency of PM generators but also effectively reduces excitation consumption. The main structure parameters and the design method were analyzed, and a simulation analysis of no-load magnetic field distribution and flux regulation ability was carried out using finite element software to verify the rationality of the hybrid excitation parallel magnetic circuit design. Moreover, the no-load, load, regulation, and voltage regulation characteristics of the designed generator were tested, and the results show that the designed generator has a wide range of voltage regulation, which can ensure stable output voltage under variable speed and load conditions.

Due to the increasing energy crisis and environmental pollution, the development of drive motors for new energy vehicles (NEVs) has become the focus of popular attention. To improve the sine of the air-gap flux density and flux regulation capacity of drive motors, a new hybrid excitation synchronous motor (HESM) has been proposed. The HESM adopts a salient pole rotor with built-in dual-V permanent magnets (PMs), non-arc pole shoes and excitation windings. The fundamental topology, operating principle and analytical model for a magnetic field are presented. In the analytical model, the rotor magnetomotive force (MMF) is derived based on the minimum reluctance principle, and the permeance function considering a non-uniform air-gap is calculated using the magnetic equivalent circuit (MEC) method. Besides, the electromagnetic performance including the air-gap magnetic field and flux regulation capacity is analyzed by the finite element method (FEM). The simulation results of the air-gap magnetic field are consistent with the analytical results. The experiment and simulation results of the performance show that the flux waveform is sinusoidal-shaped and the air-gap flux can be adjusted effectively by changing the excitation current. This study provides design methods and theoretical analysis references for this type of HESM.

Aiming at the current problems of low excitation efficiency and poor reliability of single-rotor hybrid excitation generators, the large axial length of dual-rotor structure, and difficulty in magnetic field analysis, a new type of the dual-rotor hybrid excitation generator topology with high power density is proposed, with two rotors side-by-side coaxial, sharing a set of armature windings, and the magnetic fields do not interfere with each other, so the magnetic field analysis and optimization of the two rotors can be carried out separately. The magnetic density distribution of the new permanent magnet (PM) claw pole rotor is analyzed by the joint application of the equivalent magnetic circuit method and the equivalent magnetic network method, which ensures the simplicity of calculation and improves the calculation accuracy. The multi-objective optimization of the key structural parameters is carried out based on the Latin hypercube sampling–Pareto frontier solution method. The subdomain method is improved by segmented equivalence, the unique solution of the salient-pole rotor magnetic field is obtained, and the multi-objective optimization of the salient-pole rotor is used by the particle swarm algorithm. The trial prototype was experimental, and the results showed that the output characteristics of the optimized hybrid excitation generator were significantly improved, and the overall performance of the generator was improved.

In response to the problems of large axial length and low power density of parallel hybrid excitation generator, this design proposes a brushless reverse claw pole electromagnetic and permanent magnet hybrid excitation generator for automobiles. The equivalent magnetic circuit model of the motor is established by using the equivalent magnetic network method, and the mathematical expressions of the induced electric potential and the cogging torque of the generator are derived. And the optimization of the whole machine structure with multiple design variables and optimization objectives is completed, and the “relative” optimal combination of structural parameters for the generator is determined. The performance parameters of the motor before and after optimization are compared by finite element simulation, and the rationality of the optimized design is verified. Finally, based on the optimal parameters, the prototype is manufactured and tested. The test results show that the hybrid excitation generator with brushless reverse claw pole and permanent magnet can effectively shorten the axial length and increase the power density of the whole machine. And its large electric excitation winding arrangement space can realize the wide voltage regulation range of the whole machine and also has good external characteristics and magnetizing characteristics, and the whole machine design is reasonable and effective.

This Convex-pole series-connected hybrid excitation generator has the advantages of small size and high power density, which is the main development trend of hybrid excitation generator for automobiles. The design is based on a hybrid excitation generator with built-in combined pole permanent magnet and convex pole electromagnet. The air gap magnetic density expression based on numerical analysis is derived, and a multi-objective optimization model with the rotor eccentricity and V-shaped permanent magnet clamping angle as design variables and the slot torque amplitude, no-load induced electric potential fundamental waveform amplitude and no-load induced electric potential waveform distortion rate as optimization objectives is established. The target optimization model is sampled using the Latin hypercube sample statistics, and the optimization results are screened by a combination of Pareto frontier statistics and defined parameter matching coefficients to determine the optimal rotor structure parameter combinations. Based on the optimized motor structure parameters, a prototype is fabricated and tested to verify the performance of the prototype and the correctness of the above theoretical analysis.

In this paper, a multi-objective optimization method is proposed to address the problem in the optimization process of the generator that only a specific index of a generator can be optimized to the neglect of other performance indices. Based on the equivalent magnetic circuit method, a mathematical model of the magnetic circuit of a radial-tangential combined permanent magnet pole generator is established, and the expression of the cogging torque including the pole offset angle is derived. The pole offset angle is proposed as the design variable, and no-load induction potential, air-gap flux density, and cogging torque are used as optimization targets. The relative optimal designs of permanent magnet generators are based on Pareto front statistics and defined parameter matching coefficients. Finally, a prototype is made based on the optimal structural parameters. According to the experimental results of the prototype, the correctness of the theoretical analysis and the effectiveness of the optimal design are verified.