18-10-2014, 12:16 PM
Abstracts: The project is designed to implement FACTS by TSR (Thyristor Switch Reactance). This method is used either when charging the transmission line or when there is very low load at the receiving end. Due to very low or no load, very low current flows through the transmission line and shunt capacitance in the transmission line becomes dominant. This causes voltage amplification (Ferranti Effect) due to which receiving end voltage may become double than the sending ends voltage (generally in case of very long transmission lines). To compensate this, shunt inductors are automatically connected across the transmission line. In this proposed system the lead time between the zero voltage pulse and zero current pulse duly generated by suitable operational amplifier are fed to two interrupt pins of the microcontroller, where the program takes over to bring the shunt reactors to the circuit to get the voltage duly compensated. Back to back SCRs duly interfaced through optical isolation from the programmed microcontroller are used in series for switching the reactor (in our case a choke is used). The microcontroller used in the project is of 8051 family. Further the project can be enhanced by using firing angle control methodology for smooth control of the voltage. Thus, this is better than switching reactors in steps where voltage control (also in steps) is not very precise.