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Power Quality. Mike Thornton National Sales Manager. Poor Power Quality: What is it TO YOU?. Any event related to the electrical network that makes you lose money… - Power supply failures E.g. Breakers tripping, fuses blowing - Equipment failure, malfunctioning and lifetime reduction
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Power Quality Mike Thornton National Sales Manager
Poor Power Quality: What is it TO YOU? • Any event related to the electrical network that makes you lose money… - Power supply failures E.g. Breakers tripping, fuses blowing - Equipment failure, malfunctioning and lifetime reduction E.g. - Equipment overheating (transformers, motors, …) - Damage to sensitive equipment (PCs, UPS-systems, Drives) - Capacitor problems - Electronic communication interference - System losses - Utility regulations G5/4 and penalties - Personnel issues (illness, work efficiency, …)
‘Sinusoidal’ supply voltage Non-linear load Where do harmonics come from? All non-linear loads create harmonics • A load which draws a non-sinusoidal (distorted) current, when a pure sinusoidal voltage is applied, is a non-linear load Harmonics = the distorted waveform – the 50Hz/60Hz part in the waveform
Where to find non-linear loads? Non-linear loads are everywhere and in ever increasing number! • Industrial loads (mainly 3-wire systems) • AC and DC drives, UPS-systems, … => Harmonics between phases, imbalance, sometimes reactive power • Commercial loads (mainly 4-wire systems) • All office equipment such as computers, fluorescent lighting, photo copiers, fax-machines, … => Harmonics in neutral and between phases, imbalance, sometimes reactive power • are connected between line & neutral generating 3rd harmonic in the neutral conductor • Some loads are unbalanced
The best solution to harmonic problems • Active harmonic filters • Filtering principle: cancellation of harmonics by equal and opposite harmonic generation by an active filter device Waveforms CLEAN FEEDER CURRENT LOAD CURRENT ACTIVE FILTER CURRENT = + Harmonics
Cable car application • Problem: • Utility uses ripple control signals at 1050 Hz and 1600 Hz- High frequency components present on the public network
FILTER OFF - [09/12/97] FILTER OFF - [09/12/97] 800 500 700 450 600 500 400 400 350 300 200 300 100 0 Current [A] 250 Current [Arms] -100 200 -200 -300 150 -400 100 -500 -600 50 -700 -800 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 0 5 10 15 20 25 30 35 40 45 50 Time [ms] Harmonics Cable car application Solution: ABB active filter Initial line current without ABB active filter
FILTER RUNNING - [09/12/97] FILTER RUNNING - [09/12/97] 800 500 700 450 600 500 400 400 300 350 200 300 100 0 Current [A] 250 -100 -200 200 -300 150 -400 -500 100 -600 50 -700 -800 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 0 5 10 15 20 25 30 35 40 45 50 Time [ms] Harmonics Cable car application Solution: ABB active filter Filtered line current with ABB active filter Current [Arms]
MV LV L1 (R) Protection Ith (L): 100ARMS N: 65-80% * Ith L2 (Y) L3 (B) N PQFT NL Loads: - Fluor. light - PCs- ... NL Loads: - Fluor. light - PCs- ... NL Loads: - Fluor. light - PCs- ... Neutral protection overload
Neutral protection overload • H3 in neutral with and without filter Without filter: - IH3 150 ARMSWith filter: - IH3 0 ARMS I [100 A/div] Without filter I [100 A/div] With filter Time [10 ms/div]
THE solution to poor power quality • ABB premium class Active Filters: PQFI PQFK PQFM
Power Quality Solutions • Power Factor Correction • Passive Harmonic Filters • Active Harmonic Filters • Flicker – Dynamic Compensation
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