Energy Meter & Protection

1. SUBSTATION METERING AND
PROTECTION

2. Power Transmission system
132/
230/400kV
12-15kV 33kV
Power
Plant Transformer
Power
plant
Switch
Yard
Transmission
line
Switch
Yard Transformer
Local
Distribution
network

3. TYPES OF SUBSTATIONS
 Air Insulated Substations
 Gas Insulated Substations
 Outdoor
 Indoor
Air Insulated Substations Gas Insulated Substations

4. AIR INSULATED SUBSTATION CONSISTS OF
• Transformers
• Circuit Breakers
• Current and Voltage Instreumentation transformers
• Isolator
• Bus bar systems
• Surge Arresters
• Control Monitoring and operational systems
• Capacitor banks

10. EQUIPMENT OF CONTROL PANEL
 Ammeter
 Voltmeter
 Energy Meter
 Mega Wattmeter
 MVA Meter
 Relay ( Over current Relay, Earth Fault Relay &
Differential Relay)
 Control Switch
 Auxiliary Relay
 Indicator lamp

11. WHAT IS ENERGY METER?
 The energy meter is an electrical measuring device,
which is used to record Electrical Energy
Consumed over a specified period of time in terms
of units.
 The most common unit of measurement on the
electricity meter is the kilowatt hour [kWh], which is
equal to the amount of energy used by a load of
one kilowatt over a period of one hour.

12.  For Direct current DC Power
Can be carried out using a voltmeter and an am
meter
For Alternating Current AC
Active Power
Reactive Power
Apparent Power
Angle between Voltage and current
LLVIP 
sinLL IVQ 
cosLL IVP 
22
QPS 


15. CT RATIO, PT RATIO &
MULTIPLICATION FACTOR
CTPT DETAILS
CAPACITY
PT : 11KV/110V, 100VA
CT : 20/5A 10VA
Accuracy : 0.5 Class
CAPACITY
PTR : 11 KVA/110V
CTR : 10/5A
Accuracy : 0.5 Class
MULTIPLYING FACTOR
MF = X X Dial MF
Adopted PTR
Meter PTR Meter CTR
Adopted CTR

16. NATURE AND CAUSES OF FAULT IN 11 KV OR 33 KV LINE
• Conductors clashing in the wind
• Breakdown of Conductor
• Tree branches falling on overhead conductors
• Aanimals or birds getting curious
• Careless motor vehicle drivers
• Lightning strikes
• Insulator Crack
•
• Operating error : leaving earths connected etc
• Some are more permanent:

17. Effects of faults
1. Heavy Short circuit current may cause Damage of
equipment
2. Fire Hazards
3. Loss of system stability , Individual generator in power
system may lose synchronism, resulting in a complete
shutdown of power system ( BLACK OUT)
4. Interruption of supply consumer, thereby causing a loss
of revenue

18. PROTECTIVE RELAY
 A automatic Device which detects an abnormal
condition in an electrical circuit and causes a circuit
breaker to isolate the faulty elements of the system
and may gives alarm to alert operator.
Line CT Relay Trip coil
Circuit
Breaker

19.  MCGG 52/82
MiCOM
 P121/122
 CDG
OVER CURRENT AND EARTH FAULT RELAY USED
IN WZPDCL AREA