12-10-2010, 03:36 PM
PLC Report (1).rar (Size: 856.78 KB / Downloads: 223)
Power Line Communication
ABSTRACT
The project titled ‘Power Line Communication’ is aimed to transfer data through 230V ac supply line using power line communication modem interfaced with an embedded microcontroller. The supply voltage of the 230V ac line, the current consumption of the load and the power consumed by the load at the transmitter end and the number of units measured are the parameters that are communicated between the transmitter and receiver.
The project consists of two major units namely
1. Data Transmission unit.
2. Data Receiver unit.
In the power unitization unit the 230V ac supply line is directly connected to the single phase bidirectional power/ energy chip and a load is connected across its input to obtain the RMS voltage reading. A current transformer is connected to obtain the RMS current reading. The chip generates pulses, the rate of which depends on the capacity of the load. These pulses are read by the microcontroller as an external interrupt. Power is calculated by the number of pulses generated for a user defined time. From power calculation voltage and current reading are read by the microcontroller.
The voltage, current, the counted pulses and the amount of power drawn by the load can be monitored at the LCD at the receiver unit. These parameters are transmitted by a modem through the ac power supply line.
The Basic firmware (software for microcontroller) is written in C language and compiled using C compiler (Codevision). The compiler produces the final machine code of the program and it is stored in the Flash memory of microcontroller.
At the power distribution unit the parameters that are transferred through the ac supply line are decoded by the modem and read by the microcontroller interfaced with the modem and displayed at the LCD. The data communication does not require any protocol and hence is protocol independent. The rate of data transfer is 300bps and the modem is equipped with AC coupling circuit which provides high noise immunity and reliable data communication.