Import and Export of Electrical Energy
By:- NK BHATI Yadav Measurements , Udaipur.
A specifically designed programme for Da Afghanistan Breshna
Sherkat (DABS) Afghanistan1
Areas Covered Under this Module Power flow principles Import and
export of power Metering point and energy flow Power flow quadrants
and power factor Reactive and apparent energy flow Various energy
registers in energy measurement
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Power Flow
Electricity
Power System
Power System
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Measurement Reference
Utility A A B
Utility B
Current transformer connection polarity6/3/2010 copyright YMPL
Udaipur 4
EHV BUS
HV BUS
P1
P2
P2
P1
Power flow to Voltage bus is taken positive (import) Current
transformer connection polarity (p2 to bus side)
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Example of small tie line-20 MW 4 MVR 20 MW -4 MVR
Load with green Arrows indicating Amount of MW flow
Bus 2204 MW 102 MVR
Bus 11.00 PU
1.00 PU 106 MW 0 MVR -14 MW 4 MVR 14 MW -4 MVR 1.00 PU 102 MW 51
MVR 150 MW AGC ON 37 MVR AVR ON 100 MW
150 MW AGC ON -34 MW 116 MVR AVR ON 10 MVR 34 MW -10 MVR
Note the power balance at each bus
Home AreaUsed to control output of generator
Bus 3
Direction of arrow is used to indicate direction of real power
(MW) flowcopyright YMPL Udaipur 6
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Power Flow Quadrants: IEC62053-23V
Q4PF: Leading /capacitive Export Reactive Power
Import Active Power
Q1PF: lagging/ Inductive
Q3PF: lagging /Inductive Export Active Power Import Reactive
Power
Q2copyright YMPL UdaipurPF: Leading / capacitive
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Power ComponentsV 00
900 2700 I Quadrature component
In phase component 18006/3/2010 copyright YMPL Udaipur 8
Power Flow QuadrantsVoltage vector Quadrant 4 kW Import kVAr
(capacitive) Export kW kVAr kW + - - Quadrant 1 kW Import kVAr
(Inductive) Import kW + kVAr + kVAr + kW export kVAr (capacitive)
Import Quadrant 2 kW -
kVAr - kW export kVAr (Inductive) export Quadrant 3
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Energy Flow conditions- case 1
A Gen
B Gen
Load Load
Q1: meter B6/3/2010
KW +, KVAr +copyright YMPL Udaipur 10
Energy Flow conditions- case 2
A Gen
B Gen
Load Load
Q2: meter B KW -, KVAr +6/3/2010 copyright YMPL Udaipur 11
Energy Flow conditions- case 3
A Gen
B Gen
Load Load
Q3: meter B KW -, KVAr 6/3/2010 copyright YMPL Udaipur 12
Energy Flow conditions- case 4
A Gen
B Gen
Load Load
Q4: meter B KW +, KVAr 6/3/2010 copyright YMPL Udaipur 13
Wheeling of EnergyA B
Gen
Gen
Load C Load
Gen6/3/2010 copyright YMPL Udaipur 14
Energy Registers
Active energy register Active Import Active Export
Reactive Energy register Reactive import Reactive export
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Energy Registers
Apparent energy register Apparent Import Apparent Export
Pythagoras Sum with Reactive energy Lag only lag+lead
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Metering errors
CT/ PT ratio errors CT/PT phase error Connected burden, rating,
connections errors Meter errors Class 0.5 or Class 0.2 meter
Dynamic compensation of external errors6/3/2010 copyright YMPL
Udaipur 17
In electric power transmission, wheeling is a term used to
describe either of the following: the act of transporting electric
power (megawatts or megavoltamperes) over transmission lines, or;
the act of providing the service of transporting electric power
over transmission lines.
Tie line : A connection between systems, such as electrical
power
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Any Question?
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THANK YOU!
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