Design Of A New Nc Pulsed Power Supply Of Short Electric Arc Machining

The successful application of short electric arc machine(SEAM) technology can solve the long-standing technical problem of hard-facing materials processing which machinery manufacturing industry generally faces, so it has huge potential in the field of high hardness, high strength and difficult processing conductive materials. Precision and machining efficiency are the unity of opposites, and ultimately depends on the performance indicators of pulse power supply in SEAM. So, the technology of numerical control’s high power supply has been playing more and more significant role in SEAM.In the first place, on that basis of processing principle, machining process and processing efficiency affected by the parameters of power supply are analyzed and discussed, which lays the foundation for scheme’s design and selection for power supply in SEAM.Based on the technological characteristics and design requirements of the pulse power supply in SEAM, the design scheme of power supply’s overall system is put forward, as follows. The power supply uses MCU and UC3879 as the core controller. The first level modulation module, the second level modulation module, the detection module and the feedback control module are designed based on the idea of modularization design. And the hardware scheme and detailed parameters of power supply are designed.All the sub-modules of the power supply are fully simulated, and the simulation of experiment platform of power supply is established by Simulink, SimulinkExtra and SimPowerSystems module library etc. Result of simulation shows that the feasibility of the hardware scheme and detailed parameters of power supply have been verified.And then, the neural network model of high power supply is discussed and established by using experimental data and simulation data, which form a new fitness function of genetic algorithm. And on the basis of that, we optimize the parameters of power supply through genetic algorithm based on objective weighting. Through the new method based on BP neural network and genetic algorithm(BP-GA), the conflicting problems of multi-objective parameters in traditional design can effectively be solved, and the uncertainty in design and manufacturing process is reduced.At last, the no-load tests, the full-load tests and the machining tests based on nickel base alloy are done by using the power supply. Through comparing and analyzing voltage waveform, current waveform, and machined workpiece, results show that the power supply designed by the scheme have the advantages of stable output voltage and fast response speed, which meet the expectant targets the and machining test requirements.