Induction furnace electrical panel
In order to generate an electromagnetic field, a high-power electronic system is needed that can generate the appropriate frequency in addition to supplying the electricity required to create an electromagnetic field in the coil. In this field, two control systems are needed:
Rectifier or rectifier
Inverter or frequency generator
Both of these systems are in the field of Power Electronic knowledge. At the heart of both of these systems, electronic switches with the industrial name "thyristor" are used, which are able to meet the needs of both sectors. First, the three-phase power from the 20 kV network is converted to a lower voltage such as 1000 V and enters the rectifier. In the rectifier, the input AC voltage is converted to DC voltage and then it enters the inverter to produce the desired frequency and voltage. In the inverter, the required voltage and frequency are created and directed to the electromagnetic field generating coil. Now the created magnetic field has the ability to melt steel.
In new control systems, digital controllers are used. These controllers, which are designed as software, create many and advanced control capabilities that have helped to improve the control, protection, adjustment and troubleshooting of the system. Today, in European systems, old control methods are obsolete, and other manufacturing countries such as Turkey, India, Australia and even England still use analog systems.
The use of thyristors in the control section of induction furnaces requires sufficient knowledge and expertise. Choosing the right thyristor, transferring the heat created in the thyristors, applying the right force to them and applying the on/off command with all the specifications mentioned for this semiconductor part, requires accurate design and the benefit of electronics and mechanical expertise.