Because of the aforementioned problems and demands, Hanoi Power Transmission (a subsidiary of Power Transmission Company 1 – PTC1) coordinated with VNG Trading and Service Company Limited to ran a trial of the online power insulation tester at the 220kV Ha Dong substation. This tester was manufactured by Positron Inc, which is based in Montreal, Quebec, Canada.
Mr. Le Manh Hoa – VNG’s President in a workshop at PTC1
The insulation tested detected the following faults: Electric breakdown; Electricity leaks; Contamminated surface; Carbon trace; Water formation; Cracks.
The tester’s ability to examine the electric field surrounding the insulation chain instead of measuring each insulation helps accelerate the test. The data collected from the test will be saved in the system for further analysis of the insulation quality.
- Capable of counting the branches and locating the defective branches.
- Improved operational safety.
- Smart and simple operational process.
- Non-contact with the power source helps minimize risks.
- Enable early detection of insulation leaks.
- Provide insulation and evaluate the diminishing rate of insulation over time
- Applicable for all insulation materials such as porcelain and glass…
Canadian expert – Mr. Charles – providing instructions on how to operate the device
The operation of the online insulation tester is based on the technology to measure the electric field surrounding the insulation chain… This technology uses the microprocessors (sensors) to measure, analyze and report to the computers via USB, radio waves or WIFI connection.
The sensor will move along the insulation chain. Once 1 insulator is broken, the there will be signs of chaos in the electric field, which will be reported via lights and sounds. At the same time, a graph that corresponds to the electric field will be provided for the operator to monitor and easily save for future statistics.
The results of the report will inform the operator of the exact location of the defect. There will also be lights and alarm sounds as visual warnings to the operator for instant repairing plan.
Results of the device test run at wire support phase C - feeder no 271; Type of insulator: Glass at the 220kV Ha Dong Substation
Based on the above results, for the wire support chain at phase C - feeder no 271, the Polyme insulator does not show any sign of decline in electric field, indicating normal operation of the insulation chain. At branch 23, there is insignificant decline of the electricity field. This was due to contamination, which requires a clean-up and further examination.
The trial of the online power insulation tester at the 220kV Ha Dong substation has proved the necessity of this device for the substations’s operation and management, as well as for faults investigation: to help detect the chains with weakened insulation or contamination to set up a timely replacement plan; to clearly identify the state of the fleeting faults in case of power discharge at insulation chains.
Testing the device at 220kV Ha Dong Substation
Pressing demands from customers and increasingly limited power-cuts requires both the Power industry and National Power Transmission Company to invest in testing devices for regular evaluation and devices for hotline repairs. Using the technology to run the test based on magnetic field,we can replace power-cuts with regular evaluations. This would ensure more accurate examination of composite chains to provide necessary forecasts for suitable replacement works and repair plans arranged by the units in charge of operation. /.