IJCAT - International Journal of Computing and Technology Volume 1, Issue 1, February 2014 www.IJCAT.org 125 Laboratory Based Case Study of Automated Power Distribution System by using PLC and SCADA 1 Yogesh Y. Gajbhiye, 2 P.P.Jagtap, 3 Dr.J.B.Helonde 1, 2 Electrical Department, Nagpur University, G.H.Raisoni college of Engineering Nagpur, Maharashtra, India 3 Electrical Department, Nagpur University, ITM college of Engineering Nagpur, Maharashtra, India Abstract - The aim of this paper is, firstly, to recall the basic concepts of SCADA (Supervisory Control and Data Acquisition) systems, and how Scada plays an important role in the field of power system. for the study of electrical power distribution system we need general set-up of automated power distribution laboratory in which we need the set-up of one generator panel, one transmission line panel, one receiving end panel and one Simatic s7 300 PLC System. Keywords - Simatic s7 300 PLC System, Scarab and electrical power distribution system. 1. Introduction In today’s scenario the automation system exhibit the most important and reliable system to implement. Electrical distribution system is the volatile system which always needs reliability for the stability purpose. The need of PLC and SCADA system to electrical distribution is for controlling, monitoring of distribution parameter. Supervisory Control and Data Acquisition (SCADA) systems are critically important to the procedure of Modernization of contemporary power systems, industries etc. 2. How PLC and SCADA Work Together  SCADA is installed in the computers and through serial port it is linked to PLC .  All the field devices are connected to PLC and they get signals from PLC.  Whatever applications we want to run can be executed either through PLC or SCADA. PLC basically senses input from the field (using its input cards), example: - a level sensor, a proximity switch, push button etc. Figure 1. Block diagram Depending on the logic written in the PLC logic memory, Certain decision are taken by the PLC (using CPU card and logic card).Based on the decision taken, certain output, like contactors (for driving motors), solenoids (for linear movement), lamps (for indications), valves (for flow control) etc, are driven by the PLC. SCADA receive the signal from PLC output. if some part in the power system are unhealthy the SCADA gives signal to PLC for recovery of damage. 3. Study of Panel / Equipment 3.1 GRID Source Panel 440 VOLT 3phase input is to be connected on connector provided on left side of unit.HRC fuse is provided in each phase at input.Four pole MCB is provided on panel to isolate the system from mains Source A and Source B are two three phase 440V/5Amp supplies acting as Generator.