Decreasing electrical system failures using ultrasound technology Roy Horstink UE Systems Europe
Topics for today About UE Systems What is ultrasound technology? What applications can ultrasound be used for? What will ultrasound detect in electrical applications? How to diagnose electrical problems with through ultrasound imaging.
About UE Systems UE Systems HQ in New York USA Active since 1973, over 40 years of experience European operations HQ in Netherlands with regional support offices in: Netherlands & Belgium France & North Africa Germany, Switzerland & Austria Poland Czech Republic Russia / CIS European region over 570 Engineers trained in 2013!
Advancements In Ultrasound In the early days Analog Instruments Basic troubleshooting used for listening for sounds Then came Digital Instruments Sounds could be recorded Spectrum Analysis Repeatable data & standardizations for maintenance Today Software analyses Increased emphasis on the sound recordings and data collection
Ultrasound Technology High frequency sound waves range in size from 1/8 (0.3 cm) to 5/8 (1.6 cm) Low frequency sound waves range in size from 3/4 (1.9 cm) to 56 (17 m) (assuming the average hearing is 16.5 khz)
Ultrasound Technology Multiple applications Little training needed short learning curve Used by all skill levels Integrates easily into existing programs (Infrared) Detects sounds not heard by normal hearing Typically testing at 40kHz Human hearing up to 16 / 17 khz Reporting & trending software 7
Ultrasound Technology Its very directional which makes high frequency sounds easy to locate. It can be used in noisy environments (Audible). It allows early warning of failures. It works hand in hand with other technologies. It can be used as a sorting tool (cleaning) SAFTEY FIRST, be aware of any problem before opening
Applications Compressed Air/Gas leak detection Bearing inspection Lubrication control Steamtrap inspection Electrical Inspection Corona Partial discharge Arcing Mechanical vibrations
Electrical inspection with ultrasound SWITCHGEAR TRANSFORMERS Oil or air-cooled INSULATORS RELAYS BREAKERS CABLES / JOINTS
Electrical inspection with ultrasound It can be used for inspection of high, medium and low voltage. It can also be used on open or closed systems using the contact method (enclosed switchgear or oil-cooled transformers)
Electrical inspection with ultrasound It will pick up Corona, Partial Discharge, Vibrations and Arcing. It gives the inspector an audible signature of the equipment. We can use software to analyse & trend conditions An important reason to use Ultrasound is it benefits to your safety!
Electrical inspection with ultrasound Extends the senses of the inspector to be able to listen for sounds that can not be heard with normal human hearing. INFRARED: RESISTANCE PROBLEMS ULTRASOUND: DISCHARGE PROBLEMS
Electrical Inspection Ionization forms ozone and nitrogen oxides. These combine with moisture and produce nitric acid. The nitric acid is destructive to most dielectrics and certain metallic compositions, resulting in: Corrosion
Electrical Inspection Cause: Corona Effect: Corrosion deteriorated the insulation, and led to partial discharge
Electrical Inspection Cause: Partial Discharge Effect: Undetected tracking reduced insulation value of the wire and resulted in arcing.
Electrical Inspection Failure to do anything can have catastrophic consequences
Electrical Ultrasound Emissions Ultrasonic signature of Corona, Partial Discharge, Arcing & Vibrations can easily be detected. However you must understand that db s should only be used as a reference to the actually emission location and not the severity of the emission. Your knowledge of the subject test equipment will help you to interpret the location and emission based on your knowledge of the equipment.
Electrical Ultrasound Emissions Corona
Electrical Ultrasound Emissions Partial Discharge
Electrical Ultrasound Emissions Arcing
Electrical Ultrasound Emissions Mechanical Vibrations: Air cooled transformer, loose windings
Electrical Ultrasound Emissions Corona in a 115 KV Substation
Electrical Ultrasound Emissions Partial Discharge was heard here. During an outage, etching was observed. The insulator was replaced. Corona was detected here. After cleaning, the sound was no longer present. Scan in all directions, change your angle & listen
Electrical Ultrasound Emissions What ultrasound hears What the Infrared Camera sees in that same transformer. Notice that the coolers are working and the taps all appear cool.
Electrical Ultrasound Emissions 138 KV Substation. Corona over time caused the conductor to fail due to corrosion. The conductor severed and welded itself back to the tail making a solid connection which produced no heat but did create ultrasound. Relying on Infrared alone would have missed this.
Electrical Ultrasound Emissions Oil filled transformer with partial discharge.
Electrical Ultrasound Emissions Transformer with onset of arcing
Conclusions Ultrasound is a versatile tool to add to your existing electrical inspection program Detect faults early before they become catastrophic Ultrasound is a perfect complement to infrared inspections Diagnose, trend & report electrical faults for an educated decision Better maintenance planning for shutdowns Reduces the risk of an arc flash exposure SAFETY! WWW.UESYSTEMS.EU