Slide 1: Prepared by :
Muhammad Hakim b Ab Rahman B010610076
Supervised by :
Pn Nur Hakimah binti Ab Aziz
Panel :
1. En . Aminudin b Aman
2. Pn. Elia Erwani binti Hassan Case Study On Capacitor Bank for Distribution System
Slide 2: Effect of low power factor
Reactive power problem
Decreasing losses in a distribution lines
Minimize power factor penalty Problem Statements
Slide 3: This lagging power factor has two costly disadvantages for the power user
It increases the cost incurred by the power company because more current must be transmitted than is actually used to perform useful work. This increased cost is passed on to the industrial customer by means of power factor adjustments to rate schedules. (Losses, Power Factor Penalty & Loading)
It reduces the load handling capability of the industrial plans electrical transmission system which means that the industrial power user must spend more on transmission lines and transformers to get a given amount of useful power through his plant. (Losses & Loading) Effect of Low Power
Factor
Slide 4: Condition 1
Power Factor = 0.99
Load kW= 18000 kW
Voltage = 415 V
P = VI cos Ѳ
I = P = 18000kW = 43.81 Amp
V cos Ѳ 415 x cos 8.1096
Condition 2
Power Factor = 0.7
Load kW= 18000 kW
Voltage = 415 V
P = VI cos Ѳ
I = P = 18000kW = 61.958 Amp
V cos Ѳ 415 x cos 45.57
Low Power Factor = Higher Current Reactive Power
problem
Slide 5: Objective To increase the power factor value
To study load conditions with and
without capacitor bank connected using
ERACS and PSCAD
To maintaining voltage from generation
station, transmission lines and distribution
system to the customer
To study capacitor bank (sizing component)
To study capacitor bank design ( Delta
and Star)
Slide 6: Scope Make an analitical study capacitor bank for
distribution system at Fasa B, UTeM.
Get the single line diagram for distribution system.
Determine the capacitor unit, sizing of component ,
C/K parameter and fusing calculation.
Slide 7: Project
Methodology Literature Review Calculation Simulation Result & Discussion Technical Report & Presentation
Slide 8: Literature review
This method is to study the capacitor sizing, design, and protection.
One simple single line diagram will be selected .
Learn about the ERACS and PSCAD software to simulate the simple single line diagram.
Check any sources of information from books, articles and internet. Calculation
Calculate the load profiling, capacitor unit, sizing of component , C/K parameter and fusing calculation. Simulation
Simulate the single line diagram into simulation using ERACS and PSCAD software.
To analyze the load flow (with and without capacitor bank). Result and Discussion
Compare the actual and simulation result in point view of the distribution system with and without capacitor bank.
Slide 10: Literature Review
Steps For Capacitor Sizing Load Profiling Single Line Diagram Capacitor Design Delta Design Star Design
Slide 12: Single line diagram SSU FASA B, UTeM
Slide 13: Delta and Star design
Size of Capacitor Unit A+B+C = 3ø kVar
kVar (3phase) = A+B+C
= 2/3 x (Total 3 phase µf) x w x V²/1000
W = 2 x π x f f =50Hz
V = voltage rating for capacitor Capacitor Design
Slide 14: R – Y = 462 µf
Y – B = 462 µf
B – R = 462 µf = 2/3 x (Total 3 phase µf) x w x V²/1000
= 2/3 x (462 µf+ 462 µf+ 462 µf ) x (2 x 3.142 x50) x 415²/1000
= 50 kVar
Size of Capacitor unit = 50 kVar
Slide 15: Three Phase Capacitor banks
Ic = kVar/(√3 x VLL)
= 50 kVar/(√3 x 415)
= 69.56 Amp
Single Phase Capacitor banks
Ic = kVar/(VLN)
= 50 kVar/(415/√3)
= 208.68 Amp Calculation of
Capacitive Current
Slide 16: Size of Capacitor Step Cable
Rated size (Amp) x Capacitor current
= 1.5 x Ic Ic = 69.56 Amp
= 1.5 x 69.56 Amp
= 104.34 Amp
2. Magnetic Contactor
Rated size (Amp) x Capacitor current
= 1.5 x Ic Ic = 69.56 Amp
= 1.5 x 69.56 Amp
= 104.34 Amp Sizing for
components
Slide 17: Fuse LinkRated size (Amp) x Capacitor current= 1.5 x Ic Ic = 69.56 Amp= 1.5 x 69.56 Amp = 104.34 Amp
4. Main Breaker1.35 x (Ic x all step)= 1.35 x (69.56 x 5) Ic = 69.56 Amp= 469.53 Amp
Slide 18: Sizing for
components
Slide 19: Setting for the C/K
parameter The C/K ratio is the ratio of the capacitor current for the first step and the current transformer (CT) ratio.
C/K = Q (kVar) = Icap for the first step
(1.732 x VLL x k) k
k = CT ratio
Icap per step = Q (kVar)
(1.732 x VLL)
Slide 20: Example
Size of Capacitor Bank = 250kVar, Delta
Voltage = 415V
Number of step = 5
kVar value for each step = 50kVar
Size of CT = 300/5
Calculation
k = CT ratio = 300/5 = 60
VLL = phase to phase = 415V Icap per step = Q (kVar) = 50 kVar = 69.56 Amp
(1.732 x VLL) (1.732 x 415V) C/K = Q (kVar) = Icap for the first step = 69.56 Amp
(1.732 x VLL x k) k 60
= 1.159
Slide 21: Delta 415V C/K Values
Slide 22: Delta connected banks can be fused in two different arrangements.
First an “ in line ” or “ group fuse ” method ( outside the delta) of the circuit.
The second method uses “ branch ” or “ individual fusing ” ( inside the delta) of the circuit. Outside Delta Fusing Protection for
Delta Capacitor
Slide 23: Outside Delta fusing
For smaller banks for example 3 phase capacitors (delta connected) and must be fused outside the delta.
On small banks that have only one capacitor per phase, this should be the method of choice when the neutral of the capacitor banks is not grounded.
Inside Delta fusing
For bigger capacitor bank
Units are placed in parallel, the in line fusing becomes large, and may not coordinate with the tank rupture curve of the capacitor and the upstream coordination may not be possible. Protection for
Delta Capacitor
Slide 24: Fusing calculation
Capacitor 50 kVar, Delta 415V (16.6667 kVar per phase)
Outside Delta fusing
50 kVar/(415V x √3) = 69.56 A x 1.5
= 104.34 Amp
Inside Delta fusing
16.6667kVar/415V = 40.1607 x 1.5
= 60.24 Amp Protection for
Delta Capacitor
Slide 25: Result & Analysis Component loading Component losses Power factor 0.8 1.0 1.0
Slide 26: Conclusion Analyze the load profiling
Calculated the capacitive current, capacitor
component and fusing for capacitor bank
Analyze the distribution system with and
without capacitor bank
Slide 27: Reference 1) Medium Voltage Power Capacitor Banks and Accessories, No. 50, Sir
Chittampalam A. Gardiner Mawatha, Colombo 2. Sri Lanka, CEYLON
ELECTRICITY BOARD, CEB Standard 031: 1996
http://www.ceb.lk/Specifications/31.%20MV%20CAPBANK.pdf
2) Medium and High Voltage Capacitor, Eaton MEM, Reddings Lane,
Birmingham B11 3EZ - United Kingdom, July 2008
http://www.memonline.com/pfc8.html
3) Medium Voltage Power Capacitor Banks and Accessories, CIRCUTOR, R8/9
www.olusumelektrik.com/UserFiles/listeler/circutorR8_01_GB.pdf
4) Basic of Power Factor Correction, UPE, Inc.3401 Brecksville Rd. #110
Richfield, OH 44286, Oct 2007 www.upe-inc.com/medium-voltage capacitors 5) MSD Medium Voltage Capacitor, Electronicon Germany, Issues 2007
www.upe-inc.com/pdf/MSD-Medium-Voltage-Capacitors.pdf
6) Engr. Mohamed Fuad B Faisal, Medium Voltage Capacitor Bank Design
Electrical Engineering Technical Design, Electrical Engineering Technical
Division, IEM.
7) Hadi Saadat, Power System Analisis, Second Edition, Mc Graw Hill.