A New Single-Cycle Control Method for EDM Pulse Power Supply

Abstract

The invention discloses a new single-cycle nonlinear control method of an electric spark pulse power supply. According to the processing occasion and gap load characteristics, a single-cycle current control core algorithm in the whole range is given, and the Taylor formula is used to expand it to obtain The final fitting algorithm. The input voltage signal, output voltage signal and gap current signal are sampled in real time and sent to the FPGA for calculation to obtain the duty cycle, and the PWM wave is output to control the switch tube. The method of the present invention can improve the dynamic response performance of the system. In the current rising stage, the calculated duty ratio is almost 1, so that the gap current will rise at the fastest rate. A short circuit will occur. After the short circuit occurs, the FPGA will calculate a smaller duty cycle based on the sampled voltage and current signals, which will play a protective role. It is suitable for various processing occasions such as wire electric discharge cutting, forming electric discharge machining, and micro electric discharge machining.

Description

technical field [0001] The invention belongs to the field of high-frequency pulse power supply control for multi-occasion processing such as electric discharge wire cutting, forming electric discharge, and micro electric discharge, and in particular relates to a new single-cycle control method for electric discharge pulse power supply. Background technique [0002] At present, my country's independent manufacturing capacity for key core components is insufficient, and there is an urgent need for high-efficiency, high-precision, and high-quality processing technologies. EDM technology is to form a spark discharge channel between the processing electrode and the workpiece through controllable electric energy, so as to achieve the function of material erosion. Compared with traditional contact machining, EDM can be used to process high-strength, Processing of special materials such as high hardness and high brittleness and some complex surfaces. [0003] The essence of EDM is ...

AI Technical Summary

Problems solved by technology

However, in actual processing, due to the unsmooth chip removal of the machine tool itself, short circuits often occur during the discharge process

When a short circuit occurs on the machine tool, the gap voltage will continue to drop sharply to a voltage close to 0 on the basis of maintaining the voltage. According to the characteristics of the adaptive voltage positioning control strategy, when the gap voltage drops sharply, in order to maintain the linearity of the gap voltage and gap current If the sum of the relationship remains unchanged, the gap current will continue to rise and current overshoot will occur, which will often shorten the service life of the electrode and form ablation on the surface of the workpiece, making the surface quality worse

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