Download Characteristic of current

Some technical characteristic of current-limiting reactors
Airtype - reactor
 linear magnetic behaviour (L - constant)
 spreading magnetic field around reactor (weak EMC behaviour)
 damping of reactor noise is difficult
 space consuming
 earth-quake withstand capability expensive
Oiltype – reactor
 nonlinear magnetic behaviour for high currents (L – decreasing at high currents)
 almost no electromagnetical radiation outside tank
 antinoise damping can easily be provided by enclosure or by tank wall damping
 cooling equipment (radiator bank) free placeable
PTD T PN E R&D
PTD T PN E R&D
Dr. Plötner, 2017-05-12 17:15 Seite 1
Design of oil-type current-limiting reactors
limb as gapped core
Fe-mass
Cu-mass
total mass
limb without iron core
>
<
>
three limb
height
Z0 / Z1
~ 0.8
five limb
>
<
1
core induction: - low for short-circuit limiting
- normal for power flow controlling (post-failure application)
PTD T PN E R&D
PTD T PN E R&D
Dr. Plötner, 2017-05-12 17:15 Seite 2
Initial issues to be discussed
 application
 comparison between oil-type and dry-type
- noise request
- EMC
- space available
- impedance (L-I-curve, symmetry between phases)
- earth-quake conditions
 range of magnetic linearity -> impedance at normal and at short-circuit cond.
 zero-sequence impedance
 available current level for heat-run test
 …
PTD T PN E R&D
PTD T PN E R&D
Dr. Plötner, 2017-05-12 17:15 Seite 3
Inductance over current for ConEdison New York
Inductance for 64 MVA 3~ ConEd Reactor as function of current
1.1
L L_rated

1
0.9
0.8
0.7
5
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10

15
I I_rated
20
25
PTD T PN E R&D
Dr. Plötner, 2017-05-12 17:15 Seite 4
Inductance over current for „Elstree DR2“ (400 MVA)
Inductance for 3 Elstree Reactor as function of current
1.1
L L_rated
1
0.9
0.8
0.7
1.5
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2
2.5
3
I I_rated
3.5
4
4.5
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Dr. Plötner, 2017-05-12 17:15 Seite 5
5
Example: 3~ series reactor for NGCT „Elstree DR2“
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application: post-failure load-flow control
cooling: ODAF
throuput power: 2000 MVAR
reactor power: 400 MVAR
nominal current: 2887 A, system voltage: 400 kV
induction: 1,3 T @ 2887 A
current density: 3,6 A/mm^2
PTD T PN E R&D
PTD T PN E R&D
Dr. Plötner, 2017-05-12 17:15 Seite 6
Example: 3~ series reactor for ConEdison in New York
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application: short-circuit current limitation and load-flow control
cooling: ONAN
throuput power: 358 MVAR
reactor power: 64 MVAR
nominal current: 1500 A / 2800A / 7500 A, system voltage: 138 kV
induction: 0,37 T @ 1500 A
current density: 2,3 (4,3) A/mm^2
PTD T PN E R&D
PTD T PN E R&D
Dr. Plötner, 2017-05-12 17:15 Seite 7
Test capability of the Nuremberg plant for heat-run test
reactive power for compensation (C-battery): 2 x 97 MVAr
generator power 1~: 16 MVA
generator power 3~: 26 MVA
whole power for compensation 1~: 210 MVAr
whole power for compensation 3~: 220 MVAr
max. AC-current C-battery: 2500A
max. AC-current generator: 300A
max. AC-current: 2800A
max. DC-current: 4000A (voltage 1.5kV)
PTD T PN E R&D
PTD T PN E R&D
Dr. Plötner, 2017-05-12 17:15 Seite 8