Novel single-cycle control method for electric spark pulse power supply

Abstract

The invention discloses a novel single-cycle nonlinear control method for an electric spark pulse power supply. The method comprises the following steps: giving a single-cycle current control core algorithm in a full range according to a processing occasion and a gap load characteristic, and carrying out the expansion of the single-cycle current control core algorithm through a Taylor formula to obtain a final fitting algorithm; and sampling an input voltage signal, an output voltage signal and a gap current signal in real time, sending the signals to an FPGA for calculation to obtain a duty ratio, and outputting a PWM wave to control a switching tube. According to the method, the dynamic response performance of the system can be improved, in the current rising stage, the duty ratio obtained through calculation is almost 1, so that the gap current rises at the fastest speed, in the machining process, the short-circuit situation often occurs due to the fact that chip removal of a machine tool is not conducted in time, and after the short-circuit situation occurs, the FPGA can calculate a small duty ratio according to the sampled voltage and current signals, so that a protection effect can be achieved. The method is suitable for various machining occasions such as wire cut electrical discharge machining, forming electrical discharge machining and micro electrical 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 cutting, forming electric discharge, and micro electric discharge, and particularly 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 the me...

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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