Dynamic VAR’s [D-VAR]
What are D-VAR Devices?
• Dynamic VARs… Fully integrated modular STATCOM
with proprietary 3X overload
• Instantaneously injects precise amounts of reactive
power into a network
• Can be seamlessly integrated with static shunt devices
as part of a larger solution
Ref. American Superconductors
Transmission Problems That D-VAR Can Solve:
•Voltage Stability / Voltage Collapse
-
•Uncontrolled rapid decline in system voltage
• Steady
State Voltage Regulation -
• Wind farms, radial lines, etc...
• Import/ Transfer Capability Restrictions • Limited ability to reliably import, export, or transfer power
• Mitigate
voltage flicker/ power quality -
• Wind farms, industrial facilities
Ref. American Superconductors
Single Phase DC/AC Inverter
+
1A
2A
Lf
Cf
DC
1B
AC
2B
-
• Devices 1A, 1B, 2A and 2B are IGBT’s
acting as fast switches
• Capacitors hold DC charge
• Lf and Cf are AC smoothing filter
components
Ref. American Superconductors
D-VAR Unit
Proprietary Power Electronics
Technology
Each D-VAR system has
continuous reactive power…
with temporary overload
capability up to 3 times its
continuous rating. Each
phase is individually
controlled.
Ref. American Superconductors
East End of Long Island
Southold
Orient Point
Generating
Peconic
Areas of Voltage Collapse Concerns
Mattituck
Tuthill
Riverhead
Bridgehampton
Amagansett
East Hampton
Buell
Southampton
Tiana
Double Circuit 69kV fault
Installation Site
Ref. American Superconductors
Hero
Proposed Solution for the East End Voltage Issues
8 MVA D-VAR Installed at Bridgehampton
Easthampton
69 kV
To Bridgehampton
To Buell
Load
13.8 kV
Load
To East Hampton Diesels
13.8 kV
VT
8 MVA
D-VAR
480-13800 V
Padmount
Transformers
VT
Inputs to DVAR
for Voltage Control
Ref. American Superconductors
Northeast Utilities Danbury Area
D-VAR solution by American Superconductors
Frost
Bridge
Long
Mountain
Carmel
Hill
G
Rocky
River
West
Brookfield
Shepaug
G
Bates
Rock
Stony Hill
G
Plumtree
345 kV
115 kV
Hydro Generator
Substation
Trans. Capacitor
Distrib. Capacitor
D-VAR
TM
Northeast Utilities Danbury Area
Comparison of Load-flow Results
Per Unit Voltages
Solution
Problem
SW Connecticut Imports
Ref. American Superconductors
D-VAR™ Solution’s Dynamic Voltage Support
Provides a total of -48 MVAR/+84 MVAR
600V
34.5 kV
26 MW
97%
Lagging PF
T1
60/90 MVA
with LTC
9 X 3.6 MVAR
26 units
115 kV
VTs
Utility
Interconnection
Point
The dynamic MVARs are sized to
prevent the wind farm from
tripping off-line for the faults that
the utility specified.
34.5 kV UDG
collector
system
600V
Joslyn
VBM
Switch
28 MW
97%
Lagging PF
28 units
4x2500 KVA
34500-480V
padmount
transformers
8/24 MVAR
D-VAR
D-VARs
.
Dynamic 2 x 8 x 3 = 48 MVAR
8/24 MVAR
D-VAR
600V
26 MW
97%
Lagging PF
26 units
1200 Amp
Breaker
Joslyn
VBU
Switch
Dynamic Capacitor Banks
2 x 18 MVAR = 36 MVAR
Caprock Wind Farm, New Mexico; D-VAR built by American Superconductors