Welding Inverter Power Source Control System

The paper firstly introduces the history, development, actuality about the arc welding inverter and forecasts the foreground and trend of it . That is to develop the inverter power source controled by microcomputer which adopts soft-switches .This researching task is put forward on the base of discussing the characteristics and virtues of the arc welding inverter .The structure and component of a soft-switch inverter power source are introduced in the paper. We compare the capabilities of different main circuits with each other and discuss the primary components . The design about structure, hardware circuit and anti-interference is studied in detailed .The electrocircuit and the program are work out.The paper chooses the main circuit of a inverter power source. That is a full-bridge configuration which cooperate with high frequency transformer and commutator. The design about high frequency transformer is given . The characteristics and virtues of IGBT are also studied . The amplified circuit and the commuted circuit are designed. The paper mostly researches and designs the soft-switch control system. The microprocessor 80cl96kc is the control kernel .The phase-shift chip UC3875 is adopted to produce four phase-shift pulse width modulate. Based on needs of co2 welding, the control system samples the welding voltage by Hall element Voltage Sensors .The 80cl96kc calculates dates and the chip MAX530 converts them into analogy signal ,which is then modulated by UC3875 into four phase-shift pulses. At last the pulses are used to spring IGBT after they are magnified. If the sampling voltage acted as feedback , the constant voltage could be realized depending on the control system. The function of peripheral circuits and the function of all parts of system are given in the paper . These circuits include the microprocessor circuit, the circuit used to give parameters and to show them, the PWM circuit, the circuit used to magnify. In addition, the safeguard circuit that mainly consists of over-current ,over-heat, over-voltage and low-voltage circuit are studied and designed in the paper.Reliability and anti-interference designs are also discussed and considered. In order to reduce all kinds of interferences , some handware and software measures are adopted in some correlative circuits. Some experiments are brought into effect and the experiment results show that the control system can realize the phase-shift PWM pulse, rapid speed of response, strong ability of anti-interference .At last, some experiments about this control system are advised to do in the future and some improved advices are put forward so as to overcoming deficiency of the system and expected to make the whole system more reliable and more ideal.