BRAJANATH DEY

(Meter Testing Laboratory)

TATA Power - DDL

23rd Nov. 2017

Basic Energy Metering

TYPES OF METERS AND ITS Testing

Meter Tampering

What is Energy METER ?

An electricity energy meter is a device that measures the

amount of ELECTRIC ENERGY consumed by any premises .

Energy meter operates by continuous measuring of the

instantaneous electrical parameters like VOLTAGE,

CURRENT, PF, Frequency etc. and calculate them to give

instantaneous ELECTRIC POWER which is then

INTEGRATED against time to give an ENERGY consumption.

Energy meters are typically calibrated in term of billing units

that is most commonly known as kilowatt hour.

kWh is equal to the amount of energy consumed by a load of

one kilowatt over a period of one hour that is equal to 1000

watt or 3,600,000 joules or 01 unit or 01 kWh

P = V I Cosθ ;

E = ∫ V I Cosθ.∂t

RTC

Voltage

Sensor

Current

Sensor

Multi

plierADC

Block Diagram of Electronic Energy Meter

DISPLAY

Memory

Micro

Controller

Analog to digital converter Optical Port Push Button

Review of fundamental electrical concepts

Active Energy (unit kWh)

V X I X Cos θ

Reactive Energy (unit kVArh)

V X I X Sinθ

Apparent Energy (unit kVAh)

V X I

Where,

V is line volt,

I is line current ,

θ is phase angle between volt and current ,

Cos θ is power factor

Single Phase

• Vp X Ip X cos θ

Three Phase

• 3 Phase 4 Wire 3 x Vp X Ip X cos θ

• 3 Phase 3 Wire √3 x VL X IL X cos θ

Methods of Sensing of Voltage & Current for Energy Measurement

Single Phase Electronic Whole Current Meters

Shunt Circuit (Voltage Coil)/CT Circuit (Current Coil) Meter without CT

3-Ph, 4-Wire CT Unit & Meter / Whole Current Meter

Incoming Terminals

Outgoing Terminals

Modem

Resin Cast CT Unit

Optical Port

Meter Display

Calibration LED

Name Plate

Terminal Block

CT Unit

8

CT & PTPins

CTRatio

Modem Connection

Outing Terminals

Incoming Terminals

Indoor type HT Metering Cubicle with inbuilt resin cast CT & PT

Control Cables

CT PT Unit

Outdoor type HT Metering Cubicle with CT PT Unit

SPECIFICATION STATIC METERS CONVENTIONAL ELECTRO-

MECHANICAL METERS

Life Sustainable accuracy life-over 5 years Limited life

Wear & Tear No wear & tear Lot of wear & tear Meter becomes

slow with time

Hanging of Meter Measures accurately under any conditions. Accuracy is effected with change in

angle of hanging

Protection Fully protected in case of wrong connection Get damaged with wrong

connections

Tampered Measures accurately in various Tampered

conditions

- Reverse Tamper

- Earth Tamper

- Immune to DC influence

- Distributed phase sequence

Meters either do not records in

tampered conditions or even

start running in reverse

condition

Power Loss in voltage

Circuit is continuous

& is unmetered

Loss in Voltage Circuit of Electronic meter is

low

Loss in Voltage circuit of

Conventional Meters is high

WHY ELECTRONIC METERS ???

Types of meters & Ratings of Energy

Meters

Type of Meter

Installed

Class Rating of Conventional

Meters Installed

Applied Load

Factor

Single phase 1 10-60 A Up to 10 Kw

Three Phase 1 20-100 A 11- 25 Kw

CT Operated 0.5s 100/5 A

200/5 A

26-57 Kw

58-99 Kw

HT Meter 0.5s Above 100 KW

Ranges, Rating & Accuracy Class

Tests Conducted on Energy Meters

Type Tests

• All tests as defined in relevant IS

• Test against abnormal magnetic influence as per CBIP TR 325

• DC immunity test (injection both on phase and neutral terminal)

• Test for Material used for Terminal Block and meter body as per relevant standards

• IP test

Routine Tests

AC High Voltage test Insulation test Test on limits of error Test of starting current Test of no load condition

Special Test

ESD JAMMER Magnet Temperature rise of terminal

block with 120% Imax for 6 hours Overload test at 150% of Imax

for accuracy

Tests Conducted on Energy Meters

120% I max(120A) I max (100A) Ib(20A) 0.5 Ib (10A) 0.1Ib (2A) 0.05Ib (1A)

UPF, 0.8 lead and

0.5 lag

UPF, 0.8 lead

and 0.5 lag

UPF, 0.8 lead

and 0.5 lag

UPF, 0.8 lead

and 0.5 lag

UPF, 0.8 Lead and

0.5 lag

UPF

Acceptance Test

AC High Voltage test

Insulation test

Test on limits of error with following loads

Test of meter constant

Test of starting current

Test of no load condition

Test of repeatability of error.

Test of power consumption.

Test for Immunity against external influencing signal as per the TATA POWER-DDL specification

Test for Immunity against DC Immunity as per the TATA POWER-DDL specification

Test for Immunity against Tamper conditions 38 tampers as per the TATA POWER-DDL specification

Error measurements with all abnormal condition along with ESD and magnet

Test to Influence of Harmonics

Supply voltage and frequency variation test

Testing of self-diagnostic features

All tamper tests, count increment and logging with date and time

Different types of meters & Modems

Type of Energy Meters

1-ph, 2 Wire Meter Whole Current Meter

3-ph, 4-Wire Whole Current Meter

3-ph, 4-Wire CT Operated Meter

3-ph, 3- Wire HT Meter

3-ph, 4-Wire HT Meter

DT Meter

Feeder Meter

Consumer Meter

Pre-Paid Meter

Post Paid Meter

Smart Meter

Net Meter

Evaluation of Single Phase Whole Current Electronic or Static

Energy Meters

Liquid Crystal Display (LCD)Semi-digital

Latest Postpaid Meters Pre-paid metering

Meter Reading Instruments & Modems Used in TPDDL

DMRI

CMRI

Modem

Static Energy Meter with data

transfer capabilities

Components Used for AMR & Individual Meter Vendor Software

TRANSMISSION

MEDIUM

MODEM

Software &

Systems

for data

Collection

and

processing

BCS

L&T ABBSECURE

GSM

Modem

GSM

Modem

GSM

Modem

L&TSECURE ABB

Dishonest Abstraction of Energy (DAE) – Theft by meter tampering and

its detection

DAE and its detection

Tampering of meters by:

Tilting of meters physically

Creating small pin hole in the meter body

Inserting of thin strip/film to stop the disc

Use of magnets / magnetic sensors

Deliberately inserting shunt wire between incoming and outgoing meter terminals

Inserting Switch in Neutral circuit

By interchanging the I/C phase and neutral

High Voltage High Frequency (HVHF) injection in the neutral circuit by using oscillator/spark plugs

Using external resistors inside PCB of Meter

Bye Passing of Meter through Remote control Device or CT Secondary Ckt.

Physical Tampering – Double Shunt

PHYSICAL TAMPERING IN SINGLE PHASE METERS BY INSERTING SHUNT WIRE

SHUNTS IMPLANTED AT THE REAR OF SP STATIC METER

Physical Tampering – Single Shunt

PHYSICAL TAMPERING IN SINGLE PHASE METERS BY INSERTING SHUNT WIRE

SINGLE SHUNT NEUTRAL WIRE OF METER REMOVED AND EARTHED

Physical Tampering

PHYSICAL TAMPERING IN SINGLE PHASE METERS BY EARTHING THE NEUTRAL WIRE

IN SINGLE SHUNT CASES, NEUTRAL IS GROUNDED VIA A TWO WAY SWITCH

Physical Tampering – Resistors with PCB

PHYSICAL TAMPERING IN SINGLE PHASE METERS BY INSERTING EXTERNAL RESISTORS

EXTERNAL RESISTORS IN METER PCB CIRCUIT

Physical Tampering – Re-Soldering on PCB

PHYSICAL TAMPERING IN SINGLE PHASE & THREE PHASE METERS BY RE-SOLDERING ON PCB

RESISTOR REMOVED AND RE-FIXED; RE-SET SOLDER MARKS

TAMPERING IN SINGLE PHASE METERS BY INSERTING MAGNETIC SENSOR

MAGNETIC PROXIMITY SENSOR SWITCH WAS DETECTED.

A MAGNETIC PROXIMITY SWITCH IS A DEVICE WHICH SWITCHES ON IN THE PRESENCE OF A MAGNET.

IN THIS CASE, THE SWITCH WAS DISCONNECTING THE POWER SUPPLY TO THE METER CIRCUIT

Physical Tampering

Physical Tampering – Hole on Meter Body

PHYSICAL TAMPERING IN SINGLE PHASE METERS BY CREATING HOLE ON METER BODY

HOLES ON DIFFERENT PARTS OF THE METER BODY

Physical Tampering – Remote Circuit on PCB

PHYSICAL TAMPERING IN SINGLE PHASE METERS BY INSERTING REMOTE CIRCUIT ON PCB

REMOTE CIRCUIT ON METER PCB & EL LED DISTURBED

Dishonest Abstraction of Energy (DAE)

METER DATA TAMPERING

TAMPERING IN THREE PHASE METERS BY JAMMER CIRCUIT

ESD / Jammer Tampering

TAMPERING IN THREE PHASE METERS BY JAMMER CIRCUIT

ESD / Jammer Tampering

Power failure due to Remote/Jammer

No power failure logged in same source data

Time Of Day (TOD) Feature

Seasons Month Off Peak (T0) Normal (T1) Peak (T2)

Season- 1 April- September

(Summer)

0000-0600 hrs 0600-1500 hrs 1500-2400 hrs

Season -2 October- march

(Winter)

2300-0600 hrs 0600-1700 hrs 1700-2300 hrs

Capable of measuring Cumulative Energy in kWh, kVARh & kVAH and Maximum Demand in kW & kVA with time of day (TOD) registers having profiles

6 Zones however at present 3 zones are provided i.e. Off Peak, Normal & Peak

MD Integration

Load Survey

Metering Standard:

IS13779:1999: AC Static Watthour Meters, Class 1.0 and 2.0

IS14697:1999: AC Static Transformer operated Watthour and VAR hour meters, Class 0.2 and 0.5

IS16444:2015: AC Static Direct Connected Watthour Smart Meter Class 1 & 2 –Specification

IS15884:2010: AC direct connected static Prepayment Meter for active Energy

CBIP-88/304/325: CBIP specification of ac Static Electricity Energy Meter

IS15959:2011: Data exchange for electricity meter reading, tariff and load control-companion specification

IS12346: Testing Equipment for AC Electrical Energy Meters

IS15707: Testing, Evaluation, installation and maintenance