The Research On Hard Andozinig Power Supply By Controlling Pulse Energy

Hard anodizing is a kind of technique in surface treatment of aluminum and its alloy in present industrial, which is in common use and effective. Power supply is one of the crucial factors that influence the hard anodizing technology. Now DC power supply and DC overlapped rectangle pulse power supply are the mainstream, but they have many problems in practical production so that the development of hard anodizing technology was confined. In order to improving technology and promoting relative industries'development, the power equipment is needed improving urgently.According as the theory of current restoring effect in hard anodizing technology, the subject develops a bran-new high frequency pulse trial power supply. A new way controlled pulse energy is adopted in new trial power supply. Besides high frequency and discontinuous triangle current pulse with controlled energy is used for hard anodizing of aluminum and its alloy.Double-ended flyback topology is applied flexibly in the main circuit of trial power supply. It is evolved into four-ended flyback topology. Paralleling MOSFET is selected as the power switch components. Thus in the situation of high frequency and several kilowatts, the switching losses is obviously decreased, the efficiency and power density of trial power supply is increased. The design of control cell is from the view of the load need of hard anodizing and makes the PWM theory as base. It realizes to regulating the output pulse energy in static situation and dynamic situation and controlling the output pulse track the load to regulate energy automatically. The control cell still has many protected function, such as input over-current protection and output over-voltage protection. A drive circuit is based on EXB841 and designed to drive paralleled MOSFET reliably.The design of power transform of flyback converter is different in literatures. The design means of high frequency DCM flyback converter is derivated on the base of Faraday law of electromagnetic induction in subject. Leakage of power transform has the huge influence on the performance of trial power supply. The leakage inductance effect problem of power transformer is studied deeply by establishing the circuit model of converter in energy returned stage, solving the differential equation, using Matlab and Orcad to analyze data and simulate. The way that establishes restriction bound the leakage inductance of transformer and output average voltage on a concrete DCM flyback converter is given.The power of trial power supply is 3.5kW. Through many tests, it is proved to that its performance is better than the present hard anodizing power supplies.