Effect of Power System Harmonic on Equipments Utility
- Slides: 61
Effect of Power System Harmonic on Equipments Utility Customers Manufacturers Consultants Research Organizations PQ Standard Organizations Engineers Facility Designers Research Division, PEA
Harmonic Sources SMPS 6 k+1 12 k+1 Electronic DC & AC Drive s e c a n r u Arc F Spot Welding Transformer
Symmetrical Component
Symmetrical Component
Symmetrical Component
System Connection & Harmonic Source 50 Hz Order Sym. Positive Sequence (+) 3 n + 1 Negative Sequence (-) 3 n - 1 Zero Sequence (0) 3 n H 1 + 2 - 3 0 4 + 5 - 6 0 7 +
System Connection & Harmonic ลำดบท 10 1 2 3 4 5 6 7 8 9 11 ความถ 50 100 150 200 250 300 350 0 + - 400 450 500 550 Sym. + - 0 + Zero Sequence -
Zero Sequence
Zero Sequence
Zero Sequence
Zero Sequence
Zero Sequence
Power Quality Monitoring Fluke Model 41 B Unipower Model 902 Meridian Hioki Dranetz Model 658
Harmonic Power Flow 50 Hz
Ex. Harmonic Power Flow 50 Hz
Harmonic Power Flow
Harmonic Power Flow
Harmonic Series Resonance (Low Impedance) Impedance (Z) R h 0 1 2 3 4 5 6 7 8 9 10 11 12 13 Harmonic Order
Harmonic Series Resonance (Low Impedance) R
Harmonic Series Resonance Order
Finding Harmonic Series Resonance Order 1 MVA Z = 6. 5 %
Harmonic Parallel Resonance (High Impedance) Impedance (Z) R h 0 1 2 3 4 5 6 7 8 9 10 11 12 13 Harmonic Order
Harmonic Parallel Resonance (High Impedance) IS R IC
Harmonic Parallel Resonance (High Impedance)
Harmonic Parallel Resonance (High Impedance) MVASC-HV MVA Tr %Z MVASC-LV
Harmonic Parallel Resonance (High Impedance) 100 MVASC-HV 1 MVA Z = 6. 5 % MVASC-LV
Effect on Miniature Circuit Breaker Thermal Trip (Overload) 5วนาท 1วนาท MCB Magnetic Trip (Short Circuit)
Effect on Fuse
1, 000 Time (seconds) 100 10 Effect on Fuse Maximum Clearing Time Fuse 0. 4 Sec < 0. 4 Sec 1 Minimum Melting Time 0. 10 Relay 0. 01 100 1, 000 100, 000 Rated Current (%)
Effect on Capacitor
Components of Capacitor I. II. Sequential Protection System IPE • Self-Healing Capacitor Elements • Internally Protection Elements Can • Nonflammable Dry Vermiculite Filter Resin filling III. Discharge Resistors IV. Terminal Studs V. IPE Element Dry-type - no pollution or leakage risk Thermal equalizer VI. Steel enclosure VII. Light weight easy to install Wires Non selfhealing windings Capacitor winding Winding core Sprayed contact layer Fuse Sprayed contact layer
Components of Capacitor n Electrode : a microscopically thin layer of conducting material, Polypropylene Dielectric aluminum or zinc 0. 01 microns Aluminum Foil Electrode n Dielectric : Polypropylene range from 5 to 10 microns
Effect on Capacitor Voltage Dielectric = Stress Thickness
Harmonic and Capacitor Selection 400 V 470/525 V Reactor
Effect on Relay f h I 50 Hz/h IRMS 50 Hz 120 180 300 420 540 1 2 3 5 7 9 1. 00 A 0. 92 A 0. 99 A 1. 02 A 1. 00 A 0. 46 0. 33 0. 20 0. 145 0. 11 1. 00 1. 03 1. 04 1. 03 1. 01
Effect on Relay Peak Sensing Under protected True RMS Sensing Peak Sensing Over protected Sampling
Effect on Ground Relay L 1 3. L 1 L 2 3. L 2 L 3 3. L 3 N
Effect on Meter
Effect on Conductors Skin Effect x Y
Increase in AC resistance(%) Effect on Conductors 300 250 200 150 500 mm 2 240 mm 2 100 50 185 mm 2 70 mm 2 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Harmonic Order
Effect on Conductors Copper Losses (Load Losses)
Effect on Transformer Derating (K Factor) Transformer 25 MVA at 22 k. V Fundamental 770 A at 50 Hz 3 rd 10 A 7 th 110 A 5 th 154 A 11 th 70 A
Effect on Transformer Derating (K Factor)
Effect on Transformer Derating (K Factor)
Effect on Transformer Derating (K Factor) Transformer can be operate without damaged damage
Effect on Transformer Derating (K Factor) Transformer 25 MVA at 22 k. V
Effect on Motor
Effect on Motor
With Hysteresis Losses
B, V Knee - Point Ankle -Point H, I
Harmonic Solution Passive Filter
Harmonic Solution Active Filter e g a t l m vo M ediu Low e g a t l vo Other loads Filter Load generating harmonics
หลกการทำงานของ Filter Load current with harmonics + Compensating current Active = Pure fundamental