Development Of 220KW Microarc Oxidation Ambipolar Pulse Power Supply

The erosion resistance of magnesium and its alloy are very bad. Therefore, we should carry out certain protection measure on the surface in the magnesium process of storage,usage and so on.The feature of microarc oxidation technique is simple,without pollution,the even film layer being hard, the adaptability of material being wide etc. The film has the function that the common anode oxide film has, and has the advantage that the porcelain and ceramics sprays film has, so it is the emphasis development direction of anode oxide of magnesium.The power supply parameters of microarc oxidation have an important influence on the performance of oxide film. we can study the influence through experiments.And,we can analyse and sum up the characteristic of load through collecting the power supply parameters and the film layer function parameters in the experiment, in the meanwhile, make sure the power supply characteristics and parameters the industry request, laying the foundation for the mechanism research of microarc oxidation.So,the chief problem we need resolve is developing a continuous electric source with large power and various parameters and its equipment.This passage introduces a kind of electric source with big power and the double pole pulse power that used for treating the surface of magnesium alloy with The biggest output of the power is 220 KW, among them, the biggest outputting positive electric pressure is 500 V, the biggest negative electric pressure is 200 V, the biggest positive electricity is 400 A, the biggest negative electricity is 100 A.The power supply adopt three phase, half wave and SCR commutate electric circuit, the IGBT carries on direct current to cut wave;using the IGBT establishes in series structure to carry out a pair of poles to output, using IGBT to merge the big electric current exportation of carry out the power supply, carrying out the big power exportation of the power supply thus;Usage with the 80C196 KB single slice machine for the control system of the core, make use of two timer 82C54ses respectively produce just,take half on Wednesday mutually the half control bridge to trigger pulse;Make use of a single slice the machine high speed importation to carry on synchronous signal to collect, make use of a single slice the high-speed exportation of the machine creation IGBT to drive signal;Carry on numerical PI to regulate to acquire unvarying to flow according to the electric current electric voltage feedback signal calculation deviation,the unvarying press to output characteristic;Control the system passes the 20 mA electric current wreath difference to tread a string to go communication to connect and man-machine interface to exchange a data. This kind of machine expresses a good stability and credibility in the processing.