A high-power sic submerged arc welding power supply

Abstract

The invention provides a high-power SiC submerged arc welding power supply. The high-power SiC submerged arc welding power supply is characterized by comprising at least one main circuit and digital control circuit; each main circuit comprises an electromagnetic noise inhibition module, a power frequency rectification filter module, a SiC inverse transformation current module, a high-frequency power transformer and a high-frequency quick rectification smooth module connected in sequence; the high-frequency quick rectification smooth module is connected with an arc load; the digital control circuit comprises a DSC control system, a human-computer interaction module, a safety protection module, an ultrahigh-frequency driving module and an electric signal detecting module; the ultrahigh-frequency driving module is connected with the SiC inverse transformation current module; the safety protection module is connected with the SiC inverse transformation current module; and the electric signal detection module is respectively connected with the high-frequency power transformer and the high-frequency quick rectification smooth module. A SiC power switch tube can be applied to the submerged arc welding power supply, so that the inversion frequency is greatly improved, the efficiency is high, the size is small, and the welding quality is improved.

Description

technical field [0001] The present invention relates to the technical field of submerged arc welding power supply, more specifically, relates to a high-power SiC submerged arc welding power supply. Background technique [0002] At present, in the field of submerged arc welding, due to the large current and high power required by the process, silicon rectifier and thyristor rectifier power supplies are generally used at home and abroad, which have good reliability and relatively mature technology, but the equipment is bulky, heavy and cumbersome. The energy consumption is low, the efficiency is low, and because of its structure, the dynamic and static characteristics are not ideal enough. In recent years, due to the high inverter frequency, the energy efficiency of the inverter welding power source based on MOSFET or IGBT has been greatly improved, the volume is smaller, the weight is lighter, and the dynamic characteristics are better. However, the single-tube capacity of M...

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Problems solved by technology

However, the single-tube capacity of MOSFET is small, the on-state loss is high, and the withstand voltage of the device is not high, so it is rarely used in high-power submerged arc welding inverter power supply; high-power submerged arc welding inverter power supply generally uses IGBT power tubes, but The switching frequency is low, and there are still some shortcomings:

[0003] (1) The inverter frequency is low; when used in the arc welding inverter field, the switching frequency of the high-power IGBT power tube is generally around 20kHz, and rarely exceeds 50kHz, making it difficult to further reduce the volume and weight of the power supply. The density is not high, and it is difficult to improve the dynamic characteristics of the power supply;

[0004] (2) The efficiency is not high enough; due to the tailing effect of the IGBT and the high on-state loss, the energy efficiency of the IGBT inverter submerged arc welding power supply is generally below 85%, and it is difficult to exceed 90%;

[0005] (3) The thermal tolerance of IGBT is weak; due to the extremely harsh application environment of high-power submerged arc welding power supply, some weld seams are as long as 40-50 meters, and 100% duty cycle is required to work continuously at high current for a long time. The heat loss of switching devices is high, which puts forward high requirements for heat dissipation design;

[0006] (4) Limited to the switching speed of the IGBT device, the inverter frequency is difficult to increase, and it is difficult to realize the miniaturization, light weight and modularization of the high-power submerged arc welding power supply

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