Research Of 12 V/48 V Soft Switching Power Converter For EPS

EPS is an advanced automobile steering systems in recent years, compared to conventional hydraulic steering system and mechanical steering system, EPS has a big advantage. It is the development direction of automotive steering systems. With the development of science and technology, the application of switching power supply has become more widespread. In order to achieve the light, thin, small and high efficiency requirements for switch power supply, the most effective method is to use soft-switching technology. With this technology, the power supply for the EPS can make lower cost, higher efficient, less the number of parts, low power consumption. The research on the soft-switching power supply used for EPS is significance.A soft switching power converter prototype based on TL494 is researched in this paper. It mainly composed of three basic parts. The first unit is the PWM signal generator constituted by TL494. The second unit is the PWM waveform conversion circuit constituted by CD4011 and push-pull power amplifier. The third unit is the soft-switching part formed by Boost basic circuit and quasi-resonant LC circuit. A new type of Switching Power Supply which called Boost-type soft switching power converter is based on these three parts.Firstly,the paper introduced the background and significance of research, the related content of Switching power supply. The soft-switching power conversion technology、the operating principle of Boost type and the steady-state waveform is analyzed in detail. The paper discusses the conditions to achieve soft switching, as well as the drive circuit design and logic circuits. And then, with simulation software Saber and Multisim,the several main module circuit are simulated. Also, the paper give the design method of the entire prototype and selection of major component, especially for the boost inductor with specific design. At last, a soft-switching power converter prototype based on TL494 is designed. Experimental prototype waveforms are tested, at the same time, the main performance indicators of the prototype is tested, including the load regulation and machine efficiency. The theoretical analysis is verified by simulation and experimental waveforms that the performance indicators of the prototype meet the design requirements.A reliable and practical power is obtained.Finally,a brief summary about the related work of the task is made.And according to the design, some suggestions on areas that should be improved are proposed.