t2 c power flow control
TRANSCRIPT
-
7/28/2019 T2 C Power Flow Control
1/21
1 Managed by UT-Battellefor the Department of Energy
Power Flow Control Using
Distributed Saturable Inductors
Aleks Dimitrovski
ORNL
-
7/28/2019 T2 C Power Flow Control
2/21
2 Managed by UT-Battellefor the Department of Energy
Power System Flows
,S SP Q
/S
V 0/R
V Z jX
2 cossinS R S S RS S
V V V V V P Q
X X
-
7/28/2019 T2 C Power Flow Control
3/21
3 Managed by UT-Battellefor the Department of Energy
Simple Example
3 x 150 MVA lines supply 250 MW load
All lines: z= 0.125 + j0.52 /mi, y= j6.8 S/mi
-
7/28/2019 T2 C Power Flow Control
4/21
4 Managed by UT-Battellefor the Department of Energy
Simple Example
Uncontrolled Power Flow
-
7/28/2019 T2 C Power Flow Control
5/21
5 Managed by UT-Battellefor the Department of Energy
Uncontrolled Flows Cause Problems
Overloading of lines and transformers
Reduced security margins
Power exchange contractual violations
Increased fault levels beyond rating
-
7/28/2019 T2 C Power Flow Control
6/21
6 Managed by UT-Battellefor the Department of Energy
and Inefficiencies
Increased system losses
Reduced power transfer capabilities
Opposite reactive power flows
Loop flows
loop flow,reactive power
actual realpower transfer
-
7/28/2019 T2 C Power Flow Control
7/21
7 Managed by UT-Battellefor the Department of Energy
Limited Flow Control
Switching elements on/off Regulating Transformers
Off-nominal turns ratio
Phase-shifters
Switchable shunt/series capacitors andinductors
FACTS - Flexible AC Transmission SystemDevices
-
7/28/2019 T2 C Power Flow Control
8/21
8 Managed by UT-Battellefor the Department of Energy
FACTS Devices Expensive and Bulky
100 MVAr
STATCOM
84 MVArCap Bank
TVA Sullivan S/S near Johnson City
-
7/28/2019 T2 C Power Flow Control
9/21
9 Managed by UT-Battellefor the Department of Energy
Air-Core Inductors Cheaper but Coarse
PNM Norton S/S near LANL
15 Air-CoreSeries Inductor
14,500 lbs
7 ft
6 ft
10 ft
-
7/28/2019 T2 C Power Flow Control
10/21
10 Managed by UT-Battellefor the Department of Energy
Cost Comparison
Norton air-core inductor,120 MVA:~ $1,000,000 (current estimate)
Equivalent FACTS device:
> $10,000,000
This proposal:
~ $100,000
-
7/28/2019 T2 C Power Flow Control
11/21
11 Managed by UT-Battellefor the Department of Energy
Simple Example
Inductor Controlled Power Flow
24.9 (66 mH)
-
7/28/2019 T2 C Power Flow Control
12/21
12 Managed by UT-Battellefor the Department of Energy
Simple Example
Different Load Distribution inductor On
-
7/28/2019 T2 C Power Flow Control
13/21
13 Managed by UT-Battellefor the Department of Energy
Simple Example
Different Load Distribution inductor Off
-
7/28/2019 T2 C Power Flow Control
14/21
14 Managed by UT-Battellefor the Department of Energy
Simple Example
Different Load Distribution inductor Changed
14.8 (39 mH)
-
7/28/2019 T2 C Power Flow Control
15/21
15 Managed by UT-Battellefor the Department of Energy
Iac Nac
l
Ndc
DC Source
Power line
(controlled circuit)
Idc
dc bias flux
control circuit
A
mdcac
Magnetic Amplifier
2
( )
acac
dc
N AL constl
f I
m m
m
ac circuit inductance :
controlled by dc circuit current :
-
7/28/2019 T2 C Power Flow Control
16/21
16 Managed by UT-Battellefor the Department of Energy
BH Curve of Ferromagnetic Core
1~2 T
B
H
small
Idc1 < Idc2
large
-
7/28/2019 T2 C Power Flow Control
17/21
17 Managed by UT-Battellefor the Department of Energy
Iac
ac
Nac/2
Ndc/2
DC Source
Idc
Nac/2
Ndc/2
acdc dc
Symmetrical Connection
Equal performance in both half-cycles
Cancellation of the induced voltage in the dc circuit
-
7/28/2019 T2 C Power Flow Control
18/21
18 Managed by UT-Battellefor the Department of Energy
Iac
ac
Nac/2
DC Source
Idc
Nac/2
Ndc dc
Single-Core Symmetrical Connection
Three-legged core
No induced voltage in the dc circuit
-
7/28/2019 T2 C Power Flow Control
19/21
19 Managed by UT-Battellefor the Department of Energy
Iac
ac
Ndc/2
DC Source
Idc
Ndc/2Nac
dc gaps
Single-Core with Swapped Windings
Exclusive path for ac flux instead of dc through the middle leg
Bias dc flux not impeded by gaps in the core
-
7/28/2019 T2 C Power Flow Control
20/21
20 Managed by UT-Battellefor the Department of Energy
Local DC Saturation
Iac
Nacl
Ndc/2
Idc
dc
ac
Ndc/2
gaps
DCS
ource
-
7/28/2019 T2 C Power Flow Control
21/21
21 Managed by UT-Battellef h f
Conclusions
Magnetic amplifier based device for continuouspower flow control
Combination of proven and familiar conceptswith new technology
Cheap enough for system-wide deploymentand comprehensive power flow control
Makes the grid part smart in smart grid,besides generation and load