Power Asset Engineering > Hanwootech

Best Partners in Maintenance of Electric Power Facilities
Cable VLF Testing(off-Line)
VLF Testing (Off-Line)
VLF TD/PD Diagnosis
(Old cable over 15 years)
Old Underground Cable VLF TD/PD Diagnosis
  • Test splices of the termination for the condition of the cable
  • After the diagnosis, 2nd diagnosis within 5~10 years is necessary for the managing the cable trend
  • VLF TD Diagnosis: Min : 30m / Max : 1.5km (recommend 1.0km)
  • VLF PD Diagnosis: Min : 30m / Max : 12.8km
VLF TD/PD Diagnosis (New cables)
New Underground Cable VLF TD/PD Diagnosis
    (30 min.)
  • Test splices of the termination for the condition of the cable
  • VLF TD : 0.1Hz Test Sine wave with size of phase voltage 3Uo for 30min.
  • VLF PD : VLF TD Test for 30 min., PD Test (1.0Uo, 1.25Uo, 1.5Uo, 1.75Uo)
  • VLF TD Diagnosis: Min : No limit / Max : Depend on Equipment
  • VLF PD Diagnosis: Min : 30m / Max : 12.8km
Cable IRC Testing
IRC Testing (Off-Line for old cable)
  • Isothermal Relaxation Current Measurement: After pressurization, the change in the relaxation current (discharge current) from the insulator is analyzed over time (Hopping Effect)
  • Diagnose by connecting a test wire to a cable terminal
  • Effective in diagnosing water tree, a major cause of cable accidents
  • DC 1,000V Testing ▶ No cable damage
  • Simultaneous measurement of 3-phase cable
  • KEPCO's cable maintenance Standard Diagnostic Equipment Based on High Reliability
  • Diagnosed of more than 20,000 lines, including KEPCO and large factories (1996~)
  • Reduced accident rate by diagnose, maintain, repair

  • Simultaneous measurement of 3-phase cable
  • Measurement of the circulation current, Negative current
  • Measurement of the Leakage current
CableWISE Diagnosis
(On-Line Testing)
CableWISE Testing(On-Line) / Techimp service
  • PD diagnosis and Water Tree Measurement / patent(U.S. No.6.809.523)
  • Years of CableWISE technology experience and global technology
  • Power cables, terminals, transformers, and Switchgear connected to a circuit in operation
  • Applies to all voltage Lines of 2.4kV to 345kV
LEVEL Classification Standard / actions
Low Voltage Cable Leakage Test(Off-Line Testing)
Low Voltage Leakage Test (Off-line)
Dried compressed air is injected into the cable core to automatically measure and record the changes in pressure and flow of compressed gas. Determine if cable cladding is damaged and diagnose insulator condition.
Measurement Procedure
Cable fault location & pin-point Detect
Cable fault location & pin-point
Underground cable fault point detect
(high/low voltage)
  • With fault point detector, services the exploration of underground/underwater fault point
Underground Cable Date October 12. 2015, 16:00~23:00
Station Seoul Metro
Section Station S/S ~ Electric Room
Place Station S/S
Cable Type 3.3kV CV 60㎟ 1993
Length • Length : 556m   • Fault Point : 79m
Resistance Data
R-E – 100 - ㏁
S-E – 10 - ㏁
T-E – 40,000 - ㏁
Equipment Unisat, TDR, Sound Detection
SF6 Gas, SO2, Moisture Measurement for Ground Switchgear
SF6 Gas, SO2, Moisture Measurement for switchgear
  • Because SF6 has a large ability to turn off arc as an artificial gas, it is necessary to check the condition of SF6 in order to protect switchgear from damage and corrosion caused by sparks by partial discharge and short circuit after use.
Check List
  • Portable SF6 - SO2 – Moisture Gas Analyzer capable of operating for 8 hours by using a battery
  • High-precision infrared gas detector capable of analyzing SF6 in the range of 0-100%
  • Install electrochemical SO2 sensor for finding and analyzing contaminated gas in the range of 0-100 ppm Ceramic dowpoint sensor that can analyze moisture in the range of - 65°C to +20°C dp (or ppmv)
  • Using in Permanent Mode and Sampling Mode
  • Use Recovery Bag to recover SF6 gas
  • Compatible with DILO-gas recovery systems
PD testing for Ground Switchgear
PD testing for switchgear (On-line)
Selection of KEPCO ground switchgear diagnostic equipment
  • MV Switchgear, Cable, Substation, GIS diagnosis
  • Easy portable Equipment
  • Use of multiple(5) sensors, suitable for target facilities(by usage)
  • PDtype determination(PRPD & PRPS) at the field
Measurement Methods (5 sensor Diagnostics)
Data storage PD Ismart
(On-Line 진단)
Data storage PD testing (On-line)
  • Intelligent wireless smart sensor
  • Reliable data transmission with encrypted wireless communication technology.
  • The measuring cycle of each sensor is selectable from 6 to 10000 minutes The recommended measuring cycle is 24-hour interval
  • Wireless data save and analyze.
  • Cloud analyzes the data by utilizing the Deep Learning Technology to produce a more accurate diagnostic of the data.
  • Employs a waterproof design which is suitable for outdoor applications.
iSmaer Cloud-Deep Learning
  iSmaer Cloud-Deep Learning
  • Cloud Diagnostic with Deep Learning Technology
  • Automatically generates analysis results
  • PD Type
  • Normal – Warning – Alarm results
Thermal, Visual camera diagnosis
Thermal, visible testing
Thermal Camera Inspection
  • ASS, I/S, splices, Epoxy insulator, arrester, COS, MOF, transformer, circuit breaker, etc.
  • Over-head utilities/underground utilities (switchgear/transformer)
  • Resolution required for over-head utilities : over 640*240 Pixels camera
  • Resolution required for underground utilities : over 320*240 Pixels
  • Registered in non-destructive association / Qualified ITC worker
Visual Camera Inspection
  • Over-head utilities (Extra High Voltage Electric Pole) visual check
  • Checking cracks of arrester, insulator and other over head utilities
  • Possessing DSLR resolution of over 21,460,000 camera with telephoto lens (over 28~300mm)
Ultrasonic, UV corona testing
Ultrasonic, UV corona testing
Ultrasonic testing
  • With specified categories of regulation for inspecting with ultra equipment and licensed workers are required to do such Ultra Inspection
UV corona testing
  • Over-head utilities (Extra High Voltage Electric Pole) visual check
  • Electrical discharge (corona, arc) extraction from high-voltage equipment
  • Visual display of visible light + infrared sync corona activity
Substation inspection and testing
(Thermal testing, inspection and cleaning)
Substation inspection and testing (Thermal testing, inspection and cleaning)
  • Inspection of poor utilities and maintenance of the underground substation
  • Providing the reliable power by preventing possible accident from the underground substation through routine inspection
  • Routinely inspection, thermal checking of the cable splices and joints, cleaning the utilities, crack inspection of the walls, recording 360º angle of the substation inside
schematic diagram in Substation
Concrete Pole Inspection
Concrete pole testing
Concrete Pole Inspection
  • Concrete pole inspection with using system called Vision
  • Inspection categories (width/length of the crack, auto measurement of inclined pole)