| Having overcome the disadvantages of ponderous, inefficient linear power source, switch power supplies are widely applied in power motion, industrial, communication, PC, office and family electronics equipment etc. But the ripple and low precision make it impossible to replace linear power source completely. Digital control can improve the performance of switch converter and is one of the directions of precise source. The definition of the intelligent switch power is put forward. According to the necessity of the control and application, the paper analyzes the key techniques of digital controlled intelligent source module.Based on introduction of the isolated analog signal transmission, this paper made analysis and comparison of a variety of isolated technologies, and put forward a novel digital isolating method based on serial interface D/A converter. Then, based on its typical application in a digital controlled SMPS, the corresponding experiment results show this method can realize high precision control for power electronics installation.Inverse-time overcurrent protection is used in power supply installation to fit the heat characteristic of the device's fault current. With reference to international standard characteristic equations, the equation by the integration of current term is suitable to describe the process of heat accumulation. A algorithm by curve-fitting is implemented in a microprocessor-based power supply installation. The design of hardware and software in detail is proposed and the relationship of time setting constant with heat model is simply discussed.The schemes above are applied to in a Digital Controlled Power Converter: ultimately test their feasibility and superiority... |
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