INSTALLING THE ELECTRICAL SUPPLY FOR A THREE-PHASE ARC ELECTRIC FURNACE WITH A TWO-LINK AC CONVERTER BETWEEN THE NETWORK CONNECTION AND THE FURNACE TRANSFORMER

摘要

1. Installation of power supply for a three-phase electric arc furnace (1),! - while the power supply installation has at least one furnace transformer (4), which is connected on the primary side through a two-link AC converter (5) with a three-phase supply network (3) and on the secondary side - with a three-phase electric arc furnace (1),! - while the two-link AC converter (5) has at least one rectifier (6) on the network side, at least one inverter (7) on the transformer side, and between the rectifier (6) and the inverter (7) - an intermediate link ( 8) direct current,! - in this case, each phase of the three-phase supply network (3) is connected through two converter elements (11) of the rectifier (6) with an intermediate link (8) of direct current, and! - in this case, each phase of the primary side of the transformer (4) of the furnace is connected through two conversion elements (12) of the inverter (7) with an intermediate link (8) DC,! - in this case, each conversion element (11, 12) consists of a multistage sequential circuit of submodules (13),! - in addition, each submodule (13) contains a storage capacitor (14) and an autonomous semiconductor key element (15),! - in this case, the semiconductor key elements (15) of each submodule (13) are made with the possibility of switching independently of the semiconductor key elements (15) of other submodules (13) of the same conversion element (11, 12) and other conversion elements (11, 12), so that the storage capacitor (14) of the corresponding submodule (13) is bridged using the semiconductor key element (15) of the corresponding submodule (13) in the dependent