Study Of High-power Supply For Ion Nitriding Heat Treatment

Power supply is the most important part of ion nitriding heat treatment system, its equipment used in the traditional DC power supply prone to defects such as hollow cathode effect,high dissipation,etc. Low development rate of ion nitriding pulsed power supply system developed in twentieth Century 80’s can reduce the loss and save energy, but reduce qualification rate of the workpiece. Based on the analysis of the mechanism of ion nitriding heat treatment and the diagnosis of microcosmic parameters of plasma, it is found that increasing the switching frequency power supply can increase workpiece quality and achieve the purpose of saving energy meantime. Therefore, study on dynamic response and high performance of ion nitriding heat treatment power is an important topic in this field.Soft switch has the advantages of high efficiency, easily improving the switching frequency,power conversion efficiency and quick response, it also meet the requirements of ion nitriding heat treatment technics for the power supply.Therefore,the phase shifted full bridge(PSFB)zero voltage switching(ZVS) and DC- DC converter(DC/DC)using in thermal power of ion nitriding was studied.1. This paper firstly summarizes the ion nitriding heat treatment based on the existing technology for power supply;then ion nitriding for the requirements of power supply is discussed,working principle of ion nitriding power with phase shifted full bridge zero voltage,soft switching DC DC converter as the main circuit is analyzed;small signal model of the system is modeled,and control strategy for ion nitriding power is studied.2. According to technical indexes of the power supply for ion nitriding heat treatment,the parameters design of phase shifted full bridge zero voltage soft switching DC DC converter main circuit is completed3. According to the characteristics of power supply for ion nitriding heat treatment, the control circuit with UCC28950 as the main control chip and arc discharge over-current detection and protection circuit.are designed.4. Simulation for the ion nitriding power supply system is done in MATLAB, and a 30 k W experimental prototype is made, experimental study and test results are given. The simulation and experiment results verify the feasibility and correctness of the design.