DIgSILENT PowerFactory Technical Reference Documentation
Shunt Tap Adjustment ElmShnt
DIgSILENT GmbH Heinrich-Hertz-Str. 9 72810 - Gomaringen Germany T: +49 7072 9168 0 F: +49 7072 9168 88 http://www.digsilent.de
[email protected] Version: 2016 Edition: 1
Copyright © 2016, DIgSILENT GmbH. Copyright of this document belongs to DIgSILENT GmbH. No part of this document may be reproduced, copied, or transmitted in any form, by any means electronic or mechanical, without the prior written permission of DIgSILENT GmbH. Shunt Tap Adjustment (ElmShnt)
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Contents
Contents 1 Shunt Tap Adjustment
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1.1 Common Tap Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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1.1.1 Voltage Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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1.1.2 Reactive Power Control . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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1.1.3 Power Factor Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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List of Figures
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Shunt Tap Adjustment (ElmShnt)
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1 1.1
Shunt Tap Adjustment Common Tap Adjustment
The automatic tap adjustment is using the following internal logic.
1.1.1
Voltage Control
Figure 1.1: Voltage Control
uset : voltage set point in p.u. u: measured voltage in p.u. T 1: time constant T 1 = Tctrl /(Tminctrl × krelax) Tctrl : controller Time Constant K: controller Factor K = 100% × ncapx × Kctrl × orientation Kctrl : Sensitivity dq/dv in p.u./% ncapx: Max. no of steps orientation: step orientation ( +1 for capacitive shunts, -1 for inductive shunts) ∆step: step changes Tminctrl : is the fastest controller time constant of all automatic adjusted tap-changer and shunts krelax: is the min. controller relaxation factor parameter in the load-flow command (’Advanced Options’ page) uset : is calculated from the upper and lower voltage limits according to following equation:
uset =
Shunt Tap Adjustment (ElmShnt)
uset (upper) − uset (lower) 2
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Shunt Tap Adjustment
1.1.2
Reactive Power Control
Figure 1.2: Reactive Power Control
Qset : reactive power set point in Mvar Q: measured reactive power in Mvar T 1: time constant T 1 = Tctrl /(Tminctrl × krelax ) Tctrl : Controller Time Constant K: controller factor K = ncapx/Qrmax × orientation × iQorientation ncapx: Max. no of steps Qrmax: Max. rated reactive power in Mvar orientation: step orientation ( +1 for capacitive shunts, -1 for inductive shunts) iQorient: Orientation of reactive power ( ’+Q’ = 1 for ’-Q’ = -1 ) ∆step: step changes T minctrl: is the fastest controller time constant of all automatic adjusted tap-changer and shunts krelax: is the min. controller relaxation factor parameter in the load-flow command (’Advanced Options’ page) Qset : is calculated from the upper and lower reactive power limits according to following equation:
Qset =
1.1.3
Qset (upper) − Qset (lower) in M var 2
Power Factor Control
Figure 1.3: Power Factor Control
Shunt Tap Adjustment (ElmShnt)
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Shunt Tap Adjustment
phiset : power angle set point Q: measured reactive power in Mvar P : measured active power in MW |S|: measured apparent power in MVA phi: calculated power angle phi = arctan(Q/P) T 1: time constant T 1 = Tctrl /(Tminctrl × krelax) Tctrl : Controller Time Constant K: controller factor K = ncapx/Qrmax × orientation × iQorientation ncapx: Max. no of steps Qrmax: Max. rated reactive power in Mvar orientation: step orientation ( +1 for capacitive shunts, -1 for inductive shunts) iQorient: Orientation of reactive power ( ’+Q’ = 1 for ’-Q’ = -1 ) ∆step: step changes Tminctrl : is the fastest controller time constant of all automatic adjusted tap-changer and shunts krelax: is the min. controller relaxation factor parameter in the load-flow command (’Advanced Options’ page) phiset : is calculated from the upper and lower power factor limits according to following equation: Upper power angle: For inductive power factor (ind.): phi(upper) = arccos(pf setp mx) For capacitive power factor (cap.): phi(upper) =
arccos(pf setp mx) ≥ 90◦ → 360◦ − arccos(pf setp mx) arccos(pf setp mx) ≥ 90◦ − arccos(pf setp mx)
Lower power angle: For inductive power factor (ind.): phi(lower) = arccos(pf setp mx) For capacitive power factor (cap.): phi(lower) =
arccos(pf setp mn) ≥ 90◦ → 360◦ − arccos(pf setp mn) arccos(pf setp mn) ≥ 90◦ − arccos(pf setp mn)
If the lower power angle is greater as the upper power angle then are the angle rotated, if both angles are negative the reactive power orientation iQorient is multiplied by -1.
phiset =
Shunt Tap Adjustment (ElmShnt)
phi(upper) − phi(lower) 2
in deg
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Shunt Tap Adjustment
Figure 1.4: Reactive power orientation setting for reactive power and power factor control
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List of Figures
List of Figures 1.1 Voltage Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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1.2 Reactive Power Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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1.3 Power Factor Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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1.4 Reactive power orientation setting for reactive power and power factor control . .
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