BASICS OF ENERGY METERING ANDFRAUD DETECTION

Presented By - ABHISEK NARAYAN SWAIN, B.TECH(EEE)

Regd. No.- 1301289273

Dt: 25.07.2016

CONTENTS Basics of energy meters

Types of 1-phase Energy Meters

Testing of 1-phase Energy Meter at Laboratory & Field

Types of 3-phase Energy Meters

Testing of 3-phase Energy Meters at field & Laboratory

Different Types of Tampering in Energy Meters

References

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Power in ac circuits....a quick recapPower per phase is

P=VPIP cos()Power for all 3- phases is

P=3VPIP cos() orP=V1I1 cos(1) + V2I2 cos(2) + V3I3 cos(3)

Since for a Balanced Load Power is Constant ,So P(t) = 3VPIP cos() alsoPower in terms of Line quantity P= √3 VLIL cos()

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TYPES OF 1- ENERGY METERS

1.EM induction kWh meter2.Electronic counter/Hybrid Type 3.Electronic multifunction

kWh Meter3

A TYPICAL LCD DISPLAY OF STATIC METER:-

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Measurement of power in 1- ac circuit

Single Watt-Meter Method :-

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The routine tests carried out in the Utility’s laboratory are:

1. Long period dial test

2. Non-registration with voltage alone-creep test

3. Starting current test (1) The long period dial test is done with the help of

R.S. S (Reference sub-standard) meter. The meters are started and stopped simultaneously

after connecting to the same load for a fixed period of say half an hour.

Then, Percent error = (R – A )/R x 100 R = Energy recorded by kWh meter under test A = R. S.S. meter

ROUTINE TESTS:-

 

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1- Energy Meter Testing at Laboratory

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1-phase Meter Testing at site:- Apart from testing and calibrating the meters, they must be

properly installed, as per the connection diagram. After installation of meter, its performance should be checked

at site also.  Let us take 100 watt lamp (resistive load and time constant of

energy meter is 2400 rev. /kWh. Assuming normal supply voltage, the consumption in one hour

will be 100 watt hours. The meter disc should therefore rotate (a) (2400 x 100)/1000 = 240rev./hour. Therefore, time taken for one revolution is (60 x 60)/240 = 15 seconds.

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TYPES OF 3- ENERGY METERS:-1. Whole Current Meter2. LT CT Operated Meter3. HT Meter

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3-Phase Meter Testing at Site:- All the meter details (sl. No., rating etc.) re noted down

to know whether the capacity of the installed meter is suitable for the connected load of the consumer.

Meter reading is taken starting from date , time and all parameters including instantaneous parameters, tamper data etc. From these data the present status of the meter is ascertained.

Further Meter reading instrument(MRI) is connected to the communication port of the meter. The reference standard (Standard Meter) is connected in series with the meter to find out the accuracy of the meter. With the help of clamp meter the current & voltage of all phases at the meter terminal is compared with the MRI data & meter display data. Subsequently from these data the instantaneous load drawn by the consumer is measured & compared. In case of consumer owned transformer the load of the transformer secondary side is checked and compared with that of the meter to ascertain correct recording of energy.

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Further Meter reading instrument (MRI) is connected to the communication port of the meter. The reference standard (Standard Meter) is connected in series with the meter to find out the accuracy of the meter. With the help of clamp meter the current & voltage of all phases at the meter terminal is compared with the MRI data & meter display data. Subsequently from these data the instantaneous load drawn by the consumer is measured & compared. In case of consumer owned transformer the load of the transformer secondary side is checked and compared with that of the meter to ascertain correct recording of energy

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TAMPERING:- Any intentional action on the metering system by consumer or his agent , So as to record the Consumption Lower than Actual.

TAMPER DETECTION AND LOGGING:-•Meter analyses the electrical parameters and their relationships to make a judgement whether this is a situation , which may happen due to normal load condition or is artificially caused.•Tamper detection logics can be as powerful as application knowledge and it’s appropriate implementation in s/w. Some tamper detection needs special hardware support also.

4th current sensor and support circuitMagnetic field detectionMeter cover open detection

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Potential Link Open !

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Current By Pass!

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Common Tampering Method(1):-•Open link/make it loose, on TB or inside Meter cover•Voltage coil/Sensor not getting Voltage•Meter stops ,No recording•Consumer Continues to get Power

•Missing Potential Tamper.

Some Common Tampering methods are given below:-

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Common Tampering Method(2):-

Damage GearsChange GearsDisk Rotates,But

Counter doesn’t increment proportionally

No or Less Recording

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Common Tampering Method(3):-Stop the disk rotation

by blocking it, like wire, film

Sticky materials on bearings, makes it slow, eventually may stop.

No Recording for the duration of Tamper

Change the counter readings by removing meter glass

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Common Tampering Method(4):-

Interchange in & out wire of the meter.

Meter count will decrement,if no reverse stop,else stop incrementing.

Consumer continues to get supply,but not recorded

Current reversal or CT reverse tamper

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Common Tampering Method(5):- By Pass

Strong shunt in meter to bypass most of the current

New Electronic single phase Meter

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Common Tampering Method(6):- Earthed Load

2-WIRE SYSTEM

No recording for the duration of tamper

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References: MRT Laboratory, CESU,odisha. "Handbook for Electricity Metering" by The Edison Electric

Institute—The Bible of electricity meters, continuously updated since electricity was discovered.

http://tdworld.com/smart-grid/india-spend-216-billion-smart-grid-infrastructure-2025

“People Who Steal Edison’s electricity” Daily Yellowstone journal. March 27, 1886. Retrieved 2016-07-09.

http://www.prnewswire.com/news-releases/world-loses-893-billion-to-electricity-theft-annually-587-billion-in-emerging-markets-300006515.html

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