We recently concluded the Oil & Gas project regarding the control of a 1.6 MW heater. In order to obtain the requested adjustment, the system uses thyristors (SCR).
We would like to spend a few words to explain what a thyristor (or SCR – Silicon Controlled Rectifier) is and what advantages it can bring. It is a component similar as a diode and it varies from the latter for the presence of a third terminal called “gate”, which has a signal applied for activating the diode conductivity. It is made of a quadruple layer of semiconductors p-n-p-n and is connected as a transistor couple in accordance to diagram in the figure.
This component, coupled with a PID controller (proportional-integral-derivative), reaches precision levels considerably higher compared to an electromechanic system based on contactors. Furthermore, it guarantees a higher response speed. it is also important to underline that a thyristor not only adjusts the power with a series of switch on and off, but it acts on the wave, cutting it at a determined threshold.