Power Theft Prevention Techniques

These days with emerging developments in all sectors and growing demands, electricity has become priority for every individual and every organization. The basic procedure for power supply includes power generation, power transmission and power distribution to the destinations. Naturally owing to few technical faults, losses may occur due to power dissipation by some devices. These losses can be minimized using the fast developing technology, but what about the other kind of losses? These are the losses caused deliberately by human beings for the sake of illegal access to the power distribution. This is power theft.

Power Theft in Developing Countries

In developing countries like India, power theft is one of the most prevalent issues which not only cause economic losses but also irregular supply of electricity. It hampers functioning of industries and factories, due to shortage of power supplied to them. It causes shortage of power supply to homes. It leads to loss of revenue by Government as individual enterprises may opt to install their own power generators, increases corruption in form of bribes and many more.  Ultimately it is the country’s economy which suffers along with the country’s political reputation.

Power Theft in Developed Countries

Power theft is also prevalent in developed countries like USA and Britain. According to Forbes’ report, in Canada, about $500million of electricity is stolen in Ontario and up to $6billion of electricity is pirated in USA. Many individuals who cannot afford paying the electricity bills often run wires directly to circuit breakers, tamper with meters or steal meters from vacant houses.

Check out live project details of Tampered Energy Meter Monitoring Conveyed To Control Room By GSM with User Programable Number Features

Two Ways of Power Theft

  • Power Tapping: Often power theft is done during transmission by illegal tapping of the power lines to divert the power to the required destinations. It is also done by illegal connections to the power grid stations, which are cut at the time of billing.
  • Meter fraud:  In many areas where manual reading of the meter is done, the person is often bribed to give false readings and thus the amount paid is for lesser amount of power compared to the power actually consumed. Also meters are tampered by obstructing the motion of the disk (usually electro mechanical consists of slowly spinning disks to record the power consumed)

Two Methods to Monitor or Prevent Power Theft

  • Energy Meter Tampering can be detected by using a simple arrangement of a IR led and a photodiode. It is used in cases where conventional electro mechanical energy meters are used.
Block Diagram showing energy meter tampering detection and prevention
Energy Meter Tampering Detection and Prevention by Edgefx Kits

A photodiode is placed on the shaft of the rotating disk on the meter and is illuminated with IR light from the IR LED. In normal operation, the output of the photodiode gives a logic low signal to the Microcontroller. However when the meter is tampered, i.e. the disk rotation is obstructed or the meter cover is removed, an obstacle is created between the LED and the photodiode, resulting in a logic high signal to the Microcontroller. The Microcontroller detects this change in logic signal and based on this, sends a message to the GSM modem through the level shifter Max 232. The GSM modem then sends the message about energy meter being tampered at the particular location, to the power distribution grid and appropriate action is taken accordingly.

Either the power supply to the organization or the house is cut off or energy meter is replaced in case of any damage.

A real life example of this technique of power theft prevention using Energy Meter tampering detection is shown below:

Energy Meter Tampering Detection
Energy Meter Tampering Detection
  • Power tapping can be detected by comparing the power distributed to the line and the power actually consumed by the load. This is done by installing an electronic energy meter at the load side and the meter readings are send wirelessly to the distribution unit. This reading is received by the wireless receiver and is compared with the actual power given to the load. The difference in readings indicate the error and this error signal is given to a controller which in turn controls the secondary voltage of the transformer, thus causing the transformer to stop the supply of power. Thus power theft by tapping is detected and it is prevented by halting the power to the line totally.
Block Diagram representing the power tapping detection and prevention
Power Tapping Detection and Prevention by Edgefx Kits

In this point we have seen that Electronic Energy Meters can be one solution to the problem of power theft. Let us have a brief idea about Electronic Energy Meters.

What is Electronic Energy Meter?

An electronic energy meter as its name suggests is the measuring device of the energy consumed in kWh. It unlike a conventional electromechanical meter uses basic electronic devices to compute the energy consumption.

Electronic Energy Meter
Electronic Energy Meter

5 Reasons Why Electronic Energy Meters are Preferred these Days:

  • Accuracy: The digital devices consist of auto calibration techniques and thus the power and energy measurement is neither effected by the analog nor the sampling inaccuracies.
  • Ease of Measurement: With use of modern digital signal processors, it is possible to make complex calculations in a simpler way.
  • Security: It eliminates the risk of tampering with the meter and provides efficient way of calculating the energy units.
  • Added Features: It can also come with added features like transmitting the information remotely through GSM or RF communication.
  • Stability: The components used are not prone to mechanical wear and tear like their electro mechanical parts and are hence more stable and last longer.

 Working Principle of the Electronic Energy Meter

The basic Electronic Energy meter senses the current and voltage signals from the circuitry, converts them to digital signal and makes necessary calculations to get the units of electrical energy consumed.

The electronic energy meter consists of

  • Sensors: Current and Voltage sensors are used to get the input current and voltage information from the circuit. The values of currents and voltages are conditioned to get net voltages and current.
  • Analog to Digital Converters are used to sample and quantize the analog current and voltage signals to give digital output.
  • Digital Signal Processors are used to multiply the signals and carry on further processing to calculate the reactive power, apparent power and the power factor.
  • Microcontroller or Microprocessors to make necessary calculations for measuring the energy units.
  • Display unit to display the energy consumed in kWh.

Working Example of Measuring Energy Units Using the Electronic Energy Meter

Basic Electronic Energy meter measurement takes place by counting the LED pulses at the rate of 3200 pulses per unit of electricity. A unit of electricity refers to the kilo watt units of power consumed in the given time in hours.

Block Diagram of Measurement using Electronic Energy Meter
Block Diagram of Measurement using Electronic Energy Meter by Edgefx Kits

The digital Energy meter is connected to an optoisolator and the for every electrical signal input from the Energy meter, the LED sends light pulses to the optotransistor, which converts them to electrical high and low pulses which are send to the Microcontroller. The Microcontroller is also interfaced with few push buttons to allow the user to enter relevant information about the number of hours. Based on this information and the input pulses from the optoisolator, the microcontroller makes necessary calculations to calculate the energy units consumed.

Features of few practical Energy Meters:

  • Anti tampering feature: Energy meters manufactured by HPL India provides anti tampering features by using reverse current connection to correct the energy.
  • Added Features: Energy meters manufactured by EMC provide added features like programmable pulse frequency and display of measured variables.
  • Current and voltage ratings: Most of the modern electronic energy meters have the current ratings of 10-60A and 230-400V.
  • Prepaid Energy Meters: Electronic energy meters can also be used as prepaid energy meters which have the facility of getting a definite amount of energy units for a fixed amount of amount paid through a prepaid recharge card. The meter is interfaced with a microcontroller which makes the necessary calculations based on the tariff input and the energy units input.

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