Improved Design of the Generator for Vehicles Based on TRIZ Theory

Introduction: The generator is the core component of the vehicle’s electrical system. However, the Silicon Rectifier Generator (SRG) with brushes, widely used on vehicles, has defects such as a low energy utilization rate and low power generation at low speeds. With the improvement of automobile performance, SRG cannot meet the needs of the power supply systems of modern automotive. So, a novel generator for automobiles with high efficiency and high power must be developed. A novel generator with high efficiency and energy-saving, which is suitable for a wide range of applications in vehicles, has been developed to meet the power requirements for generators. Methods: The TRIZ innovation method is applied for the development of a novel generator for automobiles in the paper, and two essential reasons causing defects are obtained by functional analysis and causal analysis in the TRIZ innovation method. In view of these two essential reasons, nine solutions are proposed by resource analysis, ideal solution analysis, contradiction analysis, and technical evolution analysis in the TRIZ tools. By evaluating nine solutions, a set of final improvement schemes for traditional SRG is proposed. On the basis of SRG, the optimization scheme adopts the form of parallel double rotors. The operating point of the permanent magnet is optimized to design the structural parameters. Based on the theory of permanent magnet motor and the design method of electric excitation generator, the structural parameters of the improved generator are designed, and the prototype is manufactured. Furtherly, the prototype is tested, and the test results are compared with those of the original SRC. The rationality of the design of the improved parallel double rotors hybrid excitation generator is verified. Results: The exciting current of IG (improved generator) is reduced by nearly 30% compared with that of SRG at idle speed. The maximum voltage fluctuation of RSG is 1.1 V, and the average voltage fluctuation is 0.93 V, while the maximum voltage fluctuation of IG is 0.82 V, and the average voltage fluctuation is 0.78 V. The voltage is increased by at least 16% under the same exciting current. Discussion: The comparative test shows that the idle performance of IG is significantly improved and the excitation consumption is significantly reduced under the rno-load idle state compared with SRC. At the same time, it can achieve good voltage regulation performance as SRG under rated load. The voltage fluctuates of IG is less when the load changes, and IG has better load characteristics than SRG. It has been proven that it is feasible to apply TRIZ theory to improve SRC and solve the defects of SRC. However, the reliability and stability of the novel generator for automotive applications will be further studied. Conclusion: With TRIZ innovation theory, a novel generator for a vehicle with reduced excitation consumption, stable idle performance, and good load characteristics has been designed. It provides a reliable method for the improved design of SRG. The successful development of the novel generator will lead to an overall improvement in the automotive electrical system.