Introduction to the electronic board of induction furnaces
These boards are digital and the controllers are implemented in software and can be installed on all types of furnaces with parallel, series, and series-parallel topologies. These boards are designed with the following goals: reducing electronic circuits and simplifying hardware, thereby increasing reliability, covering various needs in induction furnaces, such as using crucibles with different tonnages with one electrical panel, making the furnace easier to use, reducing the need for expertise for melting operators, allowing for the development of various sections in the future, high isolation of the board inputs and outputs, which significantly reduces damage to . the electronic section.
Example of an installed board
An example of a board installed on an AEG furnace at Tabriz Machine Foundry
An example of a digital board
Installed on the Indo-German EMA stove
Digital part of the control board
4 layers with two ARM processors and one CPLD
Test section:
When a furnace fails, it is necessary to perform partial tests on the furnace during and after the repair to ensure the correct functioning of the repaired part. To achieve this goal, a test system has been designed. This system has the following capabilities:
- Sending rectifier pulses: When the three-phase power voltage is interrupted, these pulses are sent to test the transformer pulses and ensure correct wiring.
- Sending inverter pulses: Inverter pulses are sent. In this case, the pulse transformer and wiring are checked.
- Rectifier test: With the presence of input voltage, only the rectifier is turned on and its performance is tested. In this case, the inverter is off.
- 10ms test: For a short period of 10ms, the device is fully and automatically turned on and off. During this period, it is not possible to increase the current and voltage to high values. By recording the waveform on the oscilloscope, the system performance can be evaluated before it is turned on permanently and the problem can be solved.
Errors:
To prevent damage to the device, various errors have been designed and built into the system, including:
Output voltage error
Output current error
Input current error
Input and output current difference error
Minimum frequency error
Error number 4 significantly increases the speed of fault detection in the power circuit.