Index Internal arc faults Ultra-fast eart hing switch (UFES) - PowerPoint PPT Presentation

EP SERVICE, 2017 ArcLimiter TM Arc flash mitigation solution for low voltage equipment using UFES

Index Internal arc faults Ultra-fast eart hing switch (UFES) ArcLimiter TM Slide 2 April 19, 2017

Internal arc faults Reasons of formation 1. Human errors 4. Overvoltage 7. Defective devices (e.g., voltage 2. Pollution 5. Bad connections transformer) 3. Animals 6. Mechanical faults Slide 3 April 19, 2017

Internal arc faults When do they occur? With operator working Without in the switchgear, 65% operator, 25% With operator in front of a closed door, 10% “One large utility has discovered an average of 1 arc flash injury every 18 months for the past 54 years.” (IEEE Std 1584 – 2002, 10.3) Slide 4 April 19, 2017

Internal arc faults Fault characteristics An arc arises when at least part of the current passes through a dielectric, usually air Maximum peak power up to 40 MW Click on and start media1 Arc temperature up to five times the surface temperature of the sun (20,000°C) Light intensity more than 2,000 times that of normal office light Slide 5 April 19, 2017

Internal arc faults Industry recognition of arc flash hazard categories IEEE 1584-2002, “Guide for Arc Flash Hazard Analysis” NFPA 70E-2009, “Standard for Electrical Safety in the Workplace” The arc flash boundary is required to be calculated by NFPA 70E. Only qualified personnel with appropriate PPE are allowed to enter boundary. Minimum level of Personal Protective Equipment as evaluated in IEEE Standard 1584 to protect workers. Slide 6 April 19, 2017

Internal arc faults Know your incident energies Determined after short circuit coordination and arc flash study High incident energies can lead to: – Undesirable and costly changes in operation – Cumbersome PPE requirements – Loss of production due to shutdown requirements Slide 7 April 19, 2017

Internal arc faults Impacts without fault limitation § Circuit breaker § Cable connection § Contact terminal compartment after compartment after after internal arc internal arc impact internal arc impact impact Slide 8 May 9, 2017

Ultra-fast earthing switch (UFES) The basis for effective protection Electronic tripping unit – Fast and reliable interface to external arc detection systems – Tripping of the UFES primary switching elements 3 Primary switching elements – Ultra-fast initiation of a 3-phase short-circuit earthing after detection of a fault by the electronics UFES wit h elect ronic t ripping unit t ype QRU100 – Elimination of the arc by resulting breakdown of the internal arc voltage Slide 9 April 19, 2017

Ultra-fast earthing switch (UFES) Sequence of tripping operation Slide 10 April 19, 2017

Ultra-fast earthing switch (UFES) UFES electronic QRU100 features Electronic tripping unit Fully compatible with the ABB arc protection system of type REA 2 Optolink inputs for connection of the REA101 relay 2 high-speed inputs (HSI) for connection of external arc detection systems Self monitoring including the Optolink connection to the REA system Logical combination of the external detection units by use of DIP-switches Testing mode for functional check Versatile monitoring options with REA system Elect ronic t ripping unit t ype QRU100 Slide 11 April 19, 2017

Ultra-fast earthing switch (UFES) Primary switching element Primary switching element – section view Primary switching element type U1 1 Vacuum interrupter and operating system integrated in one compact unit 2 3 Fast and reliable micro gas generator operating mechanism 4 Fast switching time of ~ 1.5 ms 5 Easy handling 6 Low-maintenance 7 Flexible installation 8 9 Epoxy insulator Piston 1. 6. Fixed cont act Cylinder 2. 7. Ceramic insulator Moving cont act syst em 3. 8. Moving cont act pin Micro gas generat or 4. 9. Rupture joint 5. Slide 12 April 19, 2017

Ultra-fast earthing switch (UFES) Speed differentiation W arc [kVAs]* Conventional protection device • Dramatic consequences possible * Const ant arc volt age & fault • Fire/ Explosion hazard, current for t he complet e fault heavy injuries of personnel time (depending on switchgear design) Uarc · I k · t = W arc (linear funct ion) Fast protection relay • Limit ed consequences Steel fire for equipment and personnel (depending on switchgear design) Ultra-Fast Earthing Switch type UFES Copper fire § Drast ic reduct ion of t hermal damages Cable fire § Drast ically reduced pressure rise § No consequences to be expected ! Time in ms Slide 13 April 19, 2017

Ultra-fast earthing switch (UFES) Speed and safety – pressure curves Example pressure curve, with and without UFES, in a compartment of an air insulated medium voltage switchgear, for an internal arc fault current of 130 kA (peak) / 50 kA (rms) Pressure rise wit hout UFES Pressure rise wit h UFES t TC Reaching time Overpressure for t ripping in bar criteria 1 bar = 14.7 psi t TC + ≤ 4 ms Time in ms Slide 14 April 19, 2017

Ultra-fast earthing switch (UFES) Comparison Busbar compartment after internal arc impact with active UFES protection Busbar compartment after internal arc impact without active UFES protection (50 kA / 100 ms) Slide 15 April 19, 2017

Ultra-fast earthing switch (UFES) Available as… UFES in a Service Box for top or side mounting Integration in non-ABB switchgear (e.g. Siemens) UFES as load break switch retrofit Slide 16 April 19, 2017

Ultra-fast earthing switch (UFES) Combinable arc protection by ABB UFES + REA Versatile monitoring options with REA system: – Optical detection via line or lens sensors – Overcurrent detection – Selective protection – Circuit-breaker failure protection Ultra-fast arc extinction by UFES + Certified interfaces Extremely short tripping times < 4 ms (after detection) Combinable arc prot ection UFES + REA Slide 17 April 19, 2017

Ultra-fast earthing switch (UFES) Unbeatable advantages Indirect benefit Greatly increased system and process availability by avoidance of heavy damages inside the switchgear, of the equipment and the direct environment Drastic reduction of downtimes and repair costs Direct benefit Greatly increased operator safety for switchgears Minimization of pressure rise and gases in the faulty compartment and surrounding switchgear building Slide 18 April 19, 2017

ArcLimiter TM Application example MV BUS ABB testing on LV system shows that even with 60 kA available, incident energy can be reduced MV BKR to under 1 cal/ cm 2 MV “E” RATED Result is hazard risk category (HRC) zero. FUSE 50 51 MV to LV transformers protected by either: UFES • MV circuit breaker with protective relays • A load interrupter fused switch. DT XFMR DT XFMR With ultra fast grounding system operating in 4 milliseconds, the magnitude of the LV fault level becomes a secondary consideration. LV BUS LV BUS Operating speed becomes the critical parameter. APPLICABLE N/A SYSTEM SYSTEM ArcLimiter TM tested system Slide 19 April 19, 2017

ArcLimiter TM Test of UFES grounding system LV circuit breaker compartment before (LEFT) and after (RIGHT) initiation of a 60 kA arc Slide 20 May 9, 2017

ArcLimiter TM Test of UFES grounding system Click on and start media2 Click on and start media3 Test with UFES Test without UFES (arc initiated while breaker is being racked in) Slide 21 April 19, 2017