Control method of high-voltage power supply of electron beam melting furnace and power supply device

Abstract

The invention discloses a high-voltage power supply device of an electron beam melting furnace. According to the power supply disclosed by the invention, a current transformation way including power frequency alternating current input, voltage regulation by a three-phase adjustable reactor, boosting by a three-phase boosting transformer and high-voltage rectification and filtration is adopted for output; and output high-voltage sampled signals are taken as negative feedback signals, current of a direct current control winding of the three-phase adjustable reactor is controlled by a voltage regulator, and automatic voltage regulation is performed for keeping an output voltage value of the high-voltage power supply of the electron beam melting furnace stable. The power supply disclosed by the invention is based on the control of the controllable reactor and has the characteristics of high efficiency, small public nuisance and capability of fast and effectively suppressing discharge current during discharge of the high-voltage power supply.

Description

technical field [0001] The invention relates to electron beam electric heating equipment, in particular to a control method and a power supply device for a high-voltage power supply of an electron beam melting furnace. Background technique [0002] Electron beam melting furnace is a kind of electrothermal equipment that uses the heat energy generated when high-speed electrons bombard the charge to carry out melting and heating. Compared with other vacuum melting furnaces, it has high power density and can be used for smelting and refining precious, rare and refractory metals. The vacuum degree in the furnace is high, and it is easy to prepare various high-purity materials or Special alloys and used for smelting high-quality special steel and titanium waste recycling, etc. In addition, it also has the advantage of no refractory material pollution to the charge. The development direction of the electron beam bombardment furnace is high power and multiple guns. The single powe...

AI Technical Summary

Problems solved by technology

The disadvantages are: ① Thyristor phase-shifting AC voltage regulation, polluting the power grid, EMC indicators are difficult to meet standards, and power factor is low; ② The input voltage waveform of the step-up transformer of the thyristor phase-shifting AC voltage regulation acceleration power supply is non-sinusoidal with high-order harmonics wave; in order to ensure the regulation quantity requirement, the capacity design margin of the transformer is large, and the utilization rate is low, which will increase the loss of the transformer and reduce the operating efficiency; Unfavorable for electron beam focusing, reducing electron beam flux rate

[0005] 2) The high-voltage power supply of the electron beam is controlled by open loop, that is, the high-voltage power supply is directly powered by the three-phase mains and obtained by multi-phase full-wave rectification, which can overcome some of the above shortcomings, but the fluctuations in the high-voltage operation process cannot be suppressed

For the second question, it is generally appropriate to increase the output impedance of the high-voltage power supply (mainly the leakage impedance of the step-up transformer) to reduce the high-voltage discharge current, which will inevitably affect the softening of the output characteristics of the high-voltage power supply.

In this way, it is necessary to increase the capacity of the transformer and suppress the discharge intensity at the expense of part of the efficiency. In addition, the problem of rapidly suppressing the discharge has not yet been solved.

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