MICRO CONTROLLER

BASED DISTANCE FAULT

LOCATOR IN UNDERGROUND

CABLEUnder the Guidance of: Miss.D.Mamatha

Submitted By: P.Naveen Kumar P.Madan

Md.KarimullaS.Vishore

ContentsAbstractBlock DiagramPower SupplyBlock Diagram of Micro ControllerADCRelayLiquid Crystal DisplaySoftware RequirementsWorking

AbstractThe objective of this project is to determine the distance of underground cable fault from base station in kilometers.

While a fault occurs for some reason, at that time the repairing process related to that particular cable is difficult due to not knowing the exact location of the cable fault. The proposed system is to find the exact location of the fault.

The project uses the standard concept of Ohms law i.e., when a low DC voltage is applied at the feeder end through a series resistor (Cable lines), then current would vary depending upon the location of fault in the cable.

The project is assembled with a set of resistors representing cable length in KM’s and fault creation is made by a set of switches at every known KM to cross check the accuracy of the same. The fault occurring at a particular distance and the respective phase is displayed on a LCD interfaced to the micro controller

Block Diagram

Power supply

The 230V AC supply is first stepped down to 12V AC using a step down transformer.This is then converted to DC using bridge rectifier.The AC ripples is filtered out by using a capacitor and given to the input pin of voltage regulator 7805.At output pin of this regulator we get a constant 5V DC which is used for MC and other ICs in this project

Block diagram of MC 8051

ADCAnalog to digital converters find huge application as an intermediate device to convert the signals from analog to digital form. These digital signals are used for further processing by the digital processors. Various sensors like temperature, pressure, force etc. convert the physical characteristics into electrical signals that are analog in nature.

ADC 0804 is a very commonly used 8-bit analog to digital convertor. It is a single channel IC, i.e., it can take only one analog signal as input.

RelayA relay is an electrically operated switch. Current flowing through the coil of the relay creates a magnetic field which attracts a lever and changes the switch contacts.The coil current can be on or off so relays have two switch positions and have double throw (changeover) switch contacts as shown in the diagram.

Liquid crystal display (LCD)

Most common LCDs connected to the microcontrollers are 16x2 and 20x2 displays. This means 16 characters per line by 2 lines and 20 characters per line by 2 lines, respectively. The standard is referred to as HD44780U, which refers to the controller chip which receives data from an external source (and communicates directly with the LCD.

Initialize the ports, declare timer, ADC, LCD functions.

While (1)

Display the corresponding phase name

Call ADC Function,Read ADC

Give ADC output to MC and give equalent value to LDC

Display fault location on LCD

Call Delay

Turn on relay 1 by making pin 0 high

Flowchart: