Abstract– In developingcountries, power theft is one of the most extensive issues which cause not onlyeconomic losses but also uneven supply of electricity. It hampers working ofindustries and factories, due to shortage of power supplied to them. It causes deficiencyof power supply to homes.
It leads to loss of income by Government asindividual enterprises may option to install their own power generators, increasescorruption in form of inducement and many more. Science and technology with orits advancement has engrossed human life to a great extend that imagine a worldwithout this invention is hardly possible, while technology is on their raisingslope we should also note the increasing unethical activities. With technologyview, “power theft” is non ignorable crime that is highly prevalent and at thattime is directly affects the economy of nation. Data collected our Tirunelvile District;Bhel tricky proves the necessity of this project. Key word: zero crossing detector, PIC16F886micro-controller. 1.
INTRODUCTIONOur aim of projectis to prevent the power theft by illegal tapping and meter fraud. Our projectalso implies the work as voltage stabilizer it feed a constant voltage to theload. Electric meter can be manipulated, thus causing them to stop, underregister or bypassing the meter. Consumers, who are interfere with electricmeter, efficiently use power without paying for it. This theft or fraud can be dangerousas well as deceitful.
A power regulator is a device which connects in series topower. Apparently just by keeping the device connected it will immediatelycontrol and stabilize power usages at that instant. This system can claimssavings between 20% and 30% electricity. It is known that the electricity thatcomes to our homes will not stable in nature. Our aim of project is to confinea power theft by implementing a high voltage passing through the transmissionline which will be allocated by a sub-station, by changing a taps oftransformers randomly. Further this high voltage used by consumer through oursystem in which we regulate the voltage across the load up to a definite limit.
Those consumer who are operating their electrical devices through illegalhooking or energy meter bypassing can be absolutely suffer by this highvoltage, which may cause damages to the operating devices. Fig: Block diagramof power theft by controlling microcontroller.Above blockdiagram shows the operation of power theft prevention by usingPIC16Fmicrocontroller.
The microcontroller controls the voltage across loadthrough giving a firing angle to TRIAC. TRIAC is work as a switch and itoperate when microcontroller gives the firing angle and firing angle pulse.2. METHODOLOGYIn our project weare uses a power electronic device like TRIAC to control the power. Use ofpower electronic reduces the mechanicalarcing and fast reaction time. In addition to this we also made a provision forunder/ over voltage protection which don’t have any existing energy meters.Microcontroller analyze the incoming voltage coming from line with the help ofADC (Analog to Digital Controller) present inside the microcontroller, is usedto control a positive as well as negativehalf cycle of incoming AC for that a firing angle control method is used For controllinga firing angle of any AC voltage.
It is necessary to monitor every +ve / –vehalf cycle, hence a Sine Wave Cycle Monitoring (Zero Crossing Detector) is usein our project , which inform a controller about start point of every cycle.Once controller knows the voltage across the load and signals from sine wavecycle monitor, controller calculate the firing angle and gives firing angle andfiring angle pulse to the AC to AC converter in which TRIAC is used to formstatic switch for operation, it can operated on high voltage and high frequencyas compared to mechanical switches, such as relay. The output of AC to ACconverter is further give to reactor which is nothing but a type of single corestep-up transformer.
(220v-280v transformer is used in our project), whichgives a 220v output at 140v AC input. The output 220v is further used byvarious types of load. The voltage across load is measured by the PIC-microcontrollerwith the help of potential transformer (PT).
Potential transformer is used to stepdown to voltage across the load to be measured and rectified to DC, becausemicrocontroller can read a voltage up to 5v DC only. In or project we are usingrelay for tripping the input voltage in case of very high voltage and lowvoltage which is beyond controllable limit. The relay used for 12v andcontroller can give maximum of 5v. Hence it is required to amplify the 5v-12vfor used to driver circuit. The microcontroller is used to control the firingangle of TRIAC to give the angle of triggering.
Fig:Block diagram of the proposed system The function ofvarious blocks:A. Full WaveRectifier (12VAC to 12VDC): A Full Wave Rectifier is a circuit, which convertsan 12v AC voltage into a pulsating 12V DC voltage using both half cycles of theapplied ac voltage. It uses two diodes of which one conducts during one halfcycle while the other conducts during the other half cycle of the applied.Fig:rectification in proposed systemB. VoltageRegulator (12VDC to 5VDC): A voltage regulator is designed to automaticallymaintain a constant voltage level. It isused to stabilize the DC voltages used by the controller and other elements.C.
A zero crossingdetector: It is used to monitor a sine wave cycle. It is a one type of voltagecomparator, used to detect a sine waveform transition from positive and negativethat coincides when input crosses the zero voltage condition. In alternatingcurrent, the zero-crossing is the instantaneous point at which there is no voltagepresent. In a sine wave or other simple waveform, this normally happen twiceduring each cycle. Fig:Zero Crossing Detector circuit c. Driver: AMicrocontroller digital logic output pin supplies only 10mA of current toexternal devices such as high-power relays can require less than 100mA and theyneed more voltages. In order to control such devices which use high DC current,a transistor-based driver circuit is used to amplify current to the requiredlevels. If the voltage and current levels are in moderate range, the transistoracts like a high-current switch controlled by the lower current digital logicsignal.
D. Opto-couplerand driver: An opto-coupler are designed to provide complete electricalisolation between an input low voltage side ( controller side) and output highvoltage side (TRIAC side) circuits.E. LCD: LCD(Liquid Crystal Display) screen is an electronic display module and used todisplay the operation of connected devices.F. TRIAC: Theseare Static devices used to switching operation. Static device is such devicewhich converts one type of energy or energy level into another type of energyor energy level respectively without any physical movement.G.
PICMicrocontroller: In our project we are using a PIC microcontroller which hasRISC (restricted Instruction Set Codes) architecture due to which controllerrequires only One Clock Cycle to complete a single execution. In our project weare using a 28 pin microcontroller having 16K/b of FLASH ROM, 1.2K/b of RAM,and 256 bytes of EEPROM. This controller having a inbuilt 10 Bit ADC whichrequires to measure input and output analog voltages. The operating cycle ofPIC is of 200n/s. The output port capability is to deliver 5v/40mA on each portpins.3.RESULTThe main task ofour project is to indicate the power theft, control and stabilize the power viamonitoring through microcontroller.
Our project is complete when electricitysupply authority passed the high voltage (220-280) for few minutes, then powertheft will be prevent by stabilizing the voltage through our system. In our project we give 220V-280V, aftercompleting the operation, the output voltage feed constant (280V) across theload. The actual purpose of project is to be stabilizing the voltage andprevent the theft of electricity.4.
CONCLUSIONAND FUTURE SCOPEMicrocontrollerbased device which we design is easy to implement and beneficial for bothenergy supply authority and consumer. It also provide additional feature suchas stabilize the voltage, it feed a constant voltage. It also gives theinformation of total load used in house on request at any time. The statisticalload used and profile can help consumer manage their energy consumption.
Thissystem is secured and reliable because it can access by automatic operation.This device has the capability to faced the high voltage and feed the constantvoltage to household appliances. This device help to reduced the theft of powerby implementing a high voltage through our system which stabilize the voltage,whose consumer used electricity by illegal hooking or bypassing the meter theywill suffer by this high voltage. As this device stabilizes only higher voltagebut by using active reactor in system, we can also maintain the output voltageif input voltage drop down to 160V. It will completely eliminate the powertheft and will increase revenue for the government and save electricity.