Monitoring ripple voltage in Darajat geothermal power plant

Oscilloscope is used to measure the voltage ripple in PLTP Darajat, but experienced problems because the oscilloscope cannot measured simultaneously as many as 40 points measuring. In this paper, we will show the results of the design and implementation of the PLC to measure the ripple voltage total of 40 measuring points simultaneously. This research was implemented in geothermal power plants Darajat PT. Indonesia Power. PLCs are used require analog input for 0 s / d 10 VDC, to measure the voltage of the DC BUS Panel DCS (Distributed Control System). The voltage at the terminals of the power supply are measured at +5, 15, -15 and +24 VDC and will continue to be monitored as a guarantee that the supply voltage is in accordance with the recommended. The results show that the PLC can be used in real time to measure and monitor simultaneously 40 ripple voltage measurement point with a speed of 1.5 ms of data per channel.