Upload
tracey-rose
View
226
Download
5
Tags:
Embed Size (px)
Citation preview
Voltage Regulators
Outline
• Regulator Function & Purpose• What is inside• Neutral Position • Nameplate• Bypassing• Basic Control Settings
“This workforce solution was funded by a grant awarded by the U.S. Department of Labor’s Employment and Training Administration. The solution was created by the grantee and does not necessarily reflect the official position of the U.S. Department of Labor. The Department of Labor makes no guarantees, warranties, or assurances of any kind, express or implied, with respect to such information, including any information on linked sites and including, but not limited to, accuracy of the information or its completeness, timeliness, usefulness, adequacy, continued availability, or ownership.”
This work by Alpena Community College’s Sustainable Solutions for Northeast Michigan, a Department of Labor, TAACCCT funded project, is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
Voltage Regulator Function
What is the function of a voltage regulator?
The basic function of a voltage regulator is to monitor voltage and maintain it within a preset range.
TRANS-FORMER
End of line
Vo
ltag
e
Distance
VLD = Voltage drop due to line losses
VLD
CU
RR
EN
T
TIME OF DAY
12am 6am 12pm 6pm
LOAD CURRENT VS TIME OF DAY
How to Reduce Voltage Drop
Change taps on distribution transformers Change taps of substation transformer Reconfigure system Install larger conductor Increase system voltage Install line capacitors INSTALL LINE REGULATORS
Voltage Regulators Purposes
Primary Purpose Provide regulated voltage to meet power
quality criteria Secondary Purposes
Increase revenue Peak shaving Conservation voltage reduction Metering point
Power Quality
What is the right voltage level? ±10% (132 to 108) Outage ±5% (126 to 114) Guideline ±2.5% (123 to 117) Customer
expectation
ANSI TYPE B
ShuntWinding
SeriesWinding
Vp = 1000V
Conventional two-windingtransformer
Vs = 100V
++
- -
10:1
Vp = 1000V
Step-Up Autotransformer
Vs = 1100V
++
- -
Vp = 1000V
Step-Down Autotransformer
Vs = 900V
++
- -
12
34
56
78
N+
-
+
-
Step Regulator
12
34
56
78
N+
-
+
-
Step Regulator withRevsersing Switch
Non-Bridging
N 1 2 3 4 5 6 7 8
1.25%
Bridging
N 1 2 3 4 5 6 7 8
1.25%
N 1 2 3 4 5 6 7 8
1.25%
SL
S
SHUNTWINDING
CONTROL
SERIES WINDING
CONTROLWINDING
TYPE BREGULATOR
REVERSINGSWITCH
CURRENTX-FORMER
L
Voltage Regulator Connection in a Single-Phase Circuit
SourceA
N
Bypass Switch
ShuntLightningArrester
Disconnects
SeriesLightningArrester
SL
S
L
Regulator Neutral
720V
Regulator Raise Operation
Regulator Raise Operation
And So It Goes
Picking up More Series Winding
Full Raise
To Lower Voltage
Regulator Lower Operation
7110V
Switching Checklist Putting Regulator In Service
• Check potential transformer settings.
Back Panel with Modular Terminals & Switches
Optional FO-RS232 Board
TB2
TB1
RCT2 RCT1V6, V1, & C switches
Regulator Hazards
BYPASSING
ABSOLUTELY, POSITIVELY
• A voltage regulator MUST be in the neutral position in order to “bypass” it while it is energized.
• A line/service technician must know how to operate the controls in order to maneuver the regulator into the neutral position.
AEP Safety Manual E 9.01 States:
“Voltage regulators shall be placed in the neutral position,
verified by two approved methods to be in the neutral and the control circuit made inoperative before they are
bypassed.
Voltage Regulator Neutral PositionMechanical Indication: Position indicator
Voltage Regulator Neutral Position
Electrical Indication: Neutral light
Hastings Neutral Detector
• Is a specifically designed voltmeter installed on a hot stick that measures the difference in voltage between the source and load conductors.
Low impedance bypass loop
Regulator Bypass SwitchesNon-sequenced SwitchNon-sequenced Switch
Regulator Bypass SwitchesKearney (sequenced switch)Kearney (sequenced switch)
Switching ChecklistTaking Regulator Out Of Service
• Check position of regulator.
• Place regulator in the neutral position.
• Turn control to “off”.
• Verify neutral position.
• Disable control panel power source.
• Test regulator to be in neutral.
• Operate bypass switch as required depending on type of switch.
Bypassing - Remove ProcedureRegulator Connected Line-to-Ground (GY)
Source Load
Phase A
Neutral
SL
LS
S-DIS L-DIS
B
Start 1 2 3
B O C C C
S-Dis C C C O
L-Dis C C O O
Step 1 is Critical Operation.
Bypassing - Install ProcedureRegulator Connected Line-to-Ground (GY)
Source Load
Phase A
Neutral
SL
LS
S-DIS L-DIS
B
Start 1 2 3
B C C C O
S-Dis O C C C
L-Dis O O C C
Step 2 is Critical Operation.
Switching Checklist Putting Regulator In Service
• Check potential transformer settings.
• Check regulator in neutral and off position.
• Check power source disabled.
• Test regulator to be in neutral.
• Operate bypass switch as required.
• Enable control panel power circuit.
• Place regulator control to “automatic”.
De-energizing
When should a regulator be de-energized before When should a regulator be de-energized before bypassing?bypassing?
The regulator is inoperative and cannot be returned to the neutral position.
The regulator cannot be insured to be in the neutral position.
BASIC CONTROL SETTINGS
• Set Voltage• Bandwidth• Time Delay• Control operating
mode• Reverse sensing
mode
• Configuration• System voltage
(nominal)• P.T. & C.T. ratios• Line drop
compensation
Set Voltage
• The voltage level (in 120V base) to which the control will regulate
• Settable for both forward & reverse power flow
• Forward set voltage = Function code (FC) 1
• Reverse set voltage = FC 51
• Default values are 120.0V
Bandwidth
• The total voltage range around the set voltage which the control will consider acceptable
• Acceptable voltage range defined as: Range = SV +/- 1/2 BW
Time Delay
• The number of seconds the control waits, from the start of an out-of-band condition, before initiating a tap change
• Typical values are 30 through 90 sec….
Time Delay & Cascading Regulators
3-phaseLTC
transformerTD = 30 SEC
SVRTD = 45 SEC
SVRTD = 45 SEC
SVRTD = 45 SEC
SVRTD = 75 SEC
SVRTD = 60 SEC
SVRTD = 75 SEC
Rule 1: Each succeeding regulator in series down line from the source requires a longer time delayRule 2: The minimum time delay from one regulator to the next in cascade is 15 seconds
Control Operating Mode
• Defines for the control how to respond to out-of-band conditions
• Options– Sequential (FC 42 = 0)– Time integrating (FC 42 = 1)– Voltage averaging (FC 42 = 2)
120.0120.0
121.0121.0
119.0119.0
c=0 c=10
time
SEQUENTIAL
10 sec. out-of-band 5 sec .
in-bandcounterresets tozero
c=0 c=30 2 sec delays(horizontal)
tap changes(vertical)
30 sec. out-of-band
in-band
Given: SV=120.0BW=2.0TD=30
SVSV
UBEUBE
LBELBE
SVSV
UBEUBE
LBELBE
c=0 c=10
time
TIME INTEGRATING
10 sec. out-of-band 5 sec. in-band;
counter decremented1.1/sec in-band
c=4.5 c=302 sec delays(horizontal)
tap changes(vertical)
25.5 sec.out-of-band
in-band
Given: SV=120.0BW=2.0TD=30
121.0121.0
120.0120.0
119.0119.0
SVSV
UBEUBE
LBELBE
c=0
time
VOLTAGE AVERAGING
10 sec. out-of-band 5 sec.
in-band
c=30
tap changesw/no 2 sec.delay betweentaps
in-band
Given: SV=120.0BW=2.0TD=30
averagevoltage
121.0121.0
120.0120.0
119.0119.0
out-of band
Reverse Sensing Mode
• Reverse sensing mode defines for control what RPF (Reverse Power Flow) is and how it is to react
• Options are locked forward, locked reverse, reverse idle, bi-directional, neutral idle, and co-generation
Configuration
• Defines for the control how the regulator is connected in the power system
• Necessary for proper phase relationships
• Configuration = FC 41
• Options– Wye (FC 41 = 0)– Delta lag (FC 41 = 1)– Delta lead (FC 41 = 2)
System Line Voltage
• The nominal system voltage at which the regulator is to operate
• System line voltage = FC 43
• Obtain value from regulator nameplate
Overall P.T. Ratio
• Ratio of system line voltage to voltage sensed by the control when in neutral position
• Overall PT ratio = FC 44
• Obtain value from nameplate based on selected system line voltage
Nameplate System Voltages14400 Volts, 60 Hz
TAP CONTROL INTERNAL R.C.T. TEST OVERALLIN LOAD WDG.TAP P.T. TAP TERMINAL POT.
USE VOLTS (TANK) RATIO (CONTROL) VOLTAGE RATIO
14400 E1 120:1 120 120 120:113800 E1 120:1 115 120 115:113200 E1 120:1 110 120 110:112000 E1 120:1 104 115 104:17970 E2 60:1 133 120 66.5:17620 E2 60:1 127 120 63.5:17200 E2 60:1 120 120 60:16900 E2 60:1 115 120 57.5:1
Note: The ratios may be different for each load current rating
Line Drop Compensation
VIN VOUT
I
VDROP
VCOMP
VCOMP = VOUT - VDROP
S L
SL LoadCenter
FC 6
FC 9
FC 8FC 7
R VR FC 4 X VX FC 5
R X