Single-Phase Hybrid Excitation Shaft Generator And Its Voltage Stability Characterise For Vehicle Loads

Permanent magnet synchronous generator have features of high efficiency, small size, high reliability, good dynamic performance, so it has been more and more used. However, permanent magnet synchronous generator is limited by the difficulty of adjusting output voltage. Vehicle power systems requires steady output voltage when load changes and temperature changes, in which hybrid excitation generator can solve this problem. Hybrid excitation generator has permanent magnet and excitation windings at the same time, so it has both the advantages of permanent magnet synchronous generator and excitation synchronous generator. It is becoming one of the developing trends of vehicle power system.Firstly, this paper briefly introduced the structure and basic principle of hybrid excitation generator, a prototype was designed. According to its magnetic characteristics, the equivalent magnetic circuit model is brought out. Then machine design is accomplished with the analytical method. To get sinusoidal output voltage waveform, three unite method was compared, which were tile-shaped magnet, sinusoidal magnet, and sine winding. At last the sine winding was taken into application. With finite element method, the magnetic field distribution of permanent magnet part and electric excitation part was analyzed. The working principle of the motor was verified, and no-load and rated load output performance was obtained.Secondly, in order to minimize the output power of the electrical excitation part, the output performance of the permanent magnet part was studied. Inductance was calculated accurately, and then it obtained the important structural parameters which can influence the external characteristic greatly. Each influence factor was studied for optimization, and method of voltage regulation was studied.At last, according to the results of finite element simulation, mathematical model of the single-phase hybrid excitation generator was built; dynamic and steady-state performance was analyzed. The whole system was simulated when the load and temperature changes. The digital simulation results showed that the hybrid excitation generator designed is valid, and it can satisfy the requirement. To sum up, according to design requirement, a well performance single-phase hybrid excitation generator was designed. Finite element method was used to analyze the motor's magnetic field during the operation, and Matlab was used to study the whole system performance.