Modelling of current control system to DC transmission links into Microtran program

This work presents the structural design of a power circuit and current control system for high-voltage direct-current transmission links in the electromagnetic transients program Microtran. This simulator is a version of EMTP in which additional resources were included for the simulation of systems containing power semiconductors. To represent the power system, it was used 6-pulses bridges (rectifier/inverter), shocking reactors, line DC and, naturally, AC systems. The control system, elaborated in FORTRAN77 language, endowed the rectifier station of the "constant current control" (CCC), and simulated three feedback control types: proportional, integral, and proportional-integral. The control still foresees an extinction angle supervision of the station inverter, seeking to maintain a high power factor in this converter. Among other real characteristics of HVDC system control, the routine contemplates blockade of the station for minimum and maximum fire angles, besides system of shot of the thyristor type "PIE" (pulse ignition equidistant) which is a modern technique of fire valves for links DC and static VAr systems.