Current balance system and full-bridge inverter unit of ultra-high power igbt induction heating equipment

Abstract

The invention discloses a current equalizing system of super-power IGBT induction heating equipment. The current equalizing system of the super-power IGBT induction heating equipment comprises a rectifier, at least two full-bridge inverting units arranged between the positive output end of the rectifier and the negative output end of the rectifier in a parallel mode and a resonance branch, and the resonance branch is composed of a resonance inductor and a resonance capacitor, wherein the resonance inductor and the resonance capacitor are connected in a series mode. Isolation inductors capable of isolating alternating current signals when the full-bridge inverting units heat are respectively connected between the full-bridge inverting units and the positive output end of the rectifier and between the full-bridge inverting units and the negative output end of the rectifier. The invention further discloses a full-bridge inverting unit. The current equalizing system of the super-power IGBT induction heating system equipment overcomes the technical defects that due to unbalanced distribution of current in working of a plurality of power appliances which are connected in parallel, the power switch appliances are prone to being damaged, the power switch appliances do not need to be used in a derating mode, therefore, system reliability is improved, and production cost is reduced.

Description

technical field [0001] The invention belongs to the field of power electronics, and in particular relates to an inverter system for IGBT intermediate frequency and super-audio frequency induction heating equipment, in particular to a current equalization system and a full-bridge inverter unit for super-high-power IGBT induction heating equipment. Background technique [0002] Induction heating technology currently has the highest heating efficiency and fastest speed for metal materials, and is low-consumption and environmentally friendly. It has been widely used in thermal processing, heat treatment, thermal assembly, welding and smelting of metal materials in various industries. It can not only heat the workpiece as a whole, but also heat the parts of the workpiece in a targeted manner; it can realize the deep heat penetration of the workpiece, and it can also only heat the surface and surface layer; it can not only directly heat metal materials, but also non-metallic mater...

AI Technical Summary

Problems solved by technology

When multiple IGBTs are used in parallel, because the device parameters are not completely consistent, the current passing through each IGBT is inconsistent, so only the derated IGBT is used, that is, the original stand-alone work at 50KW equipment, after two parallel connections, usually only 80KW instead of 100KW, and Work reliability will decrease

[0005] At the same time, due to frequent fluctuations in voltage, surge current, or short-circuit of the output load, the IGBT will carry a large current in a short period of time, which will easily cause breakdown of multiple IGBTs.

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