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目前我国放电加工机床中的可控硅脉冲电源一般都在脉冲回路中串有限流电阻和在放电间隙中并联电阻。限流电阻耗电量很大,在200A和350A的可控硅脉冲中粗加工时耗电量每小时分别达5度和9度。与放电间隙相并联的电阻,在高频加工时,自白地消耗了放电加工能量的10～30％。本文新提出了节能的低内阻脉冲加工理论和三个可控硅的三相触发原理。主张把目前可控硅脉冲电源中的限流电阻转移到直流电源回路之中,更进一步提出减小和完全取消在粗加工时,人为串入的限流电阻的新论点。同时提出提高与放电间隙相并联电阻的阻值的节能三相触发可控硅的电路工作原理。从而使得放电加工领域中一般可控硅脉冲电源的粗、精加工的生产率和电能利用率等几项的经济技术指标都有新的突破。从放电加工基本可控硅电路出发,导出回路电流的数学表示式。并以简化计算200A可控硅脉冲电源为例,来论证相同限流电阻在不同回路里的巨大差异。以三相触发与二相触发的工作原理的差别,来证实三相触发有利于提高并联电阻的阻值和生产率,节约电能。这些电路与目前一般使用的一些可控硅脉冲电源的电路差别很小,因此按此理论,对目前大多数使用的可控硅脉冲电源进行简单的改装,不但可使生产率和电能利用率都大大地提高,同时也降低了设备的温升,增进可控硅电源工作的可靠性。对现有脉冲电源的节能改造,有的甚至只要改变其中滤波电容的联结点就可以达到全年生产节电上万度。
At present, EDM pulse power supply in China is generally limited in the pulse loop current limiting resistor and shunt resistor in the discharge gap. The current-limiting resistor consumes a lot of power, consuming roughly 5 and 9 degrees per hour when roughing in 200A and 350A thyristors. The resistor connected in parallel with the discharge gap consumes 10 to 30% of the discharge machining energy confessively during high-frequency machining. In this paper, a new energy-saving low-resistance pulse processing theory and three SCR three-phase trigger principle. Advocated the current thyristor pulse power supply in the current limiting resistance transfer to the DC power supply circuit, further proposed to reduce and completely cancel the roughing, artificial string current limiting resistor new argument. At the same time, the working principle of an energy-saving three-phase trigger thyristor for improving the resistance in parallel with the discharge gap is proposed. As a result, several breakthroughs have been made in economic and technical indicators such as coarse and fine machining productivity and energy utilization of general thyristor pulse power sources in the field of electrical discharge machining. Starting from EDM basic SCR circuit, derive the mathematical expression of loop current. And to simplify the calculation of 200A SCR pulse power supply, for example, to demonstrate the same current limiting resistor in different circuits in the huge difference. To three-phase trigger and two-phase trigger the difference between the working principle to prove that three-phase trigger is conducive to improving the parallel resistance of the resistance and productivity, saving power. These circuits and the current general use of some of the SCR pulse power supply circuit is very small, so according to this theory, most of the current use of SCR pulse power for simple modification, not only can make productivity and power utilization are greatly Improve, but also reduce the temperature rise of the equipment, improve the work of the SCR power supply reliability. On the existing energy-saving pulse power transformation, and some even as long as the change of filter capacitor junction can reach the annual production of tens of thousands of degrees.