Title: Distribution Feeder Voltage Regulation and Control
1Distribution Feeder Voltage Regulation and Control
- W. H. Kersting
- Milsoft Utility Solutions
2Purpose of This Paper
- Present ANSI Voltage Standards
- Present Step Voltage Regulator
- What it is
- Control Settings
- Model
- IEEE 13 Node Test Feeder
- Steps in regulating voltage on the test feeder
3The ANSI Voltage Standards
- Range A
- Nominal Utilization Voltage 115 volts
- Maximum Utilization Voltage 126 volts
- Minimum Service Voltage 114 volts
- Minimum Utilization Voltage 110 volts
- Range B
- Nominal Utilization Voltage 115 volts
- Maximum Utilization Voltage 127 volts
- Minimum Service Voltage 110 volts
- Minimum Utilization Voltage 107 volts
4ANSI Range A Critical Voltages
5Voltage Drop Assumptions
- 1 Volt drop on the service drop
- 2 Volt drop on the secondary
- 3 Volt drop through the transformer
- Minimum Voltage at the Transformer Primary
Terminals will be 120 volts
6Voltage Profiles
7Step Voltage Regulator
8Type B Step Voltage Regulator
9The Step-Voltage Regulator Model
10Three Phase Voltage Regulator Model
11Model Matrix
12Compensator Circuit
13Control Panel
14Control Circuit
15Regulator Control Settings
- Voltage Level voltage to hold at the regulation
point - R and X setting (volts) Equivalent impedance
from the regulator to the regulation point - Time Delay time after a tap change required
before the tap is changed - Bandwidth allowed deviation from the set
voltage level
16Compensator Impedance
17Equivalent Line Impedance
18Bandwidth
19IEEE 13 Node Test Feeder(Modified)
20Modifications
- Line 4-12 changed to phases B-C
- Transformer 6-7 changed to Ungrounded Wye Delta
- Load at Node 7 converted to Delta-PQ
- Load at Node 8 converted to Delta-PQ
- Load at Node 14 changed to phase B with constant
Z load - Load added at Node 5 300 j145.3 kVA
21Step 1
- Select regulation point to be Node 4
- Run power-flow with source set to 126 volts
- Display Voltage Profile
- Compute compensator impedance
22Step 1 Voltage Profile
23Voltages and Currents from Power-Flow Run
24Compensator R and X Settting
25Full Load with Regs, no Caps
26Observations
- Regulator taps
- Phase a 11
- Phase b 12
- Phase c 15
- Concern about high voltage at Node 2
- Need to add shunt capacitors
27Shunt Capacitors
- Source reactive power
- Phase A 765 kvar
- Phase B 809 kvar
- Phase C 1105 kvar
- Install shunt capacitors
- Node 3 100 kvar per phases a,b,c
- Node 4 600 kvar per phases a,b,c
- Node 13 150 kvar on phase c
28Full Load with Regs and Caps
29Observations
- Regulator taps
- Phase a 5
- Phase b 6
- Phase c 7
- Notice good voltage balance
- All voltages between 120 and 122 volts at Node 4
3050 Load with all Capacitors
3150 Load with 900 kvar at Node 4 switched off
3210 Load Growth with original caps
3310 Load Growth100 kvar per phase added at node 4
34Questions?