How to choose the intermediate frequency induction  melting furnace incoming line voltage

For induction melting furnace medium frequency power supply below 1000KW, three-phase five-wire 380V, 50HZ industrial power is used, and 6-pulse single-rectifier intermediate frequency power supply is configured. For medium-frequency power supply above 1000KWY, the focus is on using 660V incoming voltage (some manufacturers use 575V or 750V). Because 575VZ or 750V is a non-standard voltage level, the accessories are not good to buy, it is recommended not to use). Configure 12-pulse double-rectifier IF power supply for two reasons: one is to increase the rated working voltage by increasing the incoming line voltage; the second is large The harmonics generated by the power will interfere with the grid. The double rectification can obtain a relatively straight DC current. The load current is a rectangular wave, and the load voltage is close to a sine wave, which reduces the impact of grid interference on other equipment.

Some users blindly pursue high voltage (some 1000KW use 900V line voltage), and achieve energy saving since low current. I don't know if this is at the expense of the life of the electric furnace. It is not worth the loss, high voltage is easy to shorten the life of electrical components. , copper platoon, cable fatigue, so that the life of the electric furnace is greatly reduced. In addition, high voltage for the electric furnace manufacturers, the raw materials are reduced in terms of materials, saving costs. Electric furnace manufacturers are certainly willing to do so (high-priced low-cost.) The ultimate loss is still the use of electric furnace manufacturers.