Operation and repairs of transformers
Operation and comprehensive services for transformers, autotransformers and chokes with voltage from 6 kV to 750 kV:
- installation of new units, including transport, preparation of the station, positioning on the station and connection to the network
- full inspections, modernizations and repairs of units in operation
- inspections and repairs of unit cooling systems
- internal audits of units at the place of installation,
- full measurements and diagnostic tests of units (winding resistance, insulation resistance of windings and bushings, magnetizing currents, capacitance and dielectric loss factor of windings and bushings, testing of mechanical winding deformation by SFRA method, testing of windings and bushings dampness by FDS method, oscillographic test of tap changers, including measuring the power consumed by the drive, measuring the ratio and checking the connection group, testing the current transformers installed on the transformer, testing the core grounding elements)
- inspections of on-load tap-changers
- localization and liquidation of unit failures
- delivery and replacement of bushings
- cleaning and painting of units
- transformer oil exchange, treatment and testing (physicochemical, chromatographic)
The operation of transformers and comprehensive maintenance services are the basis for maintaining the power grid infrastructure in efficient condition. This applies to transformers, autotransformers and chokes with nominal voltages from 6 kV to 750 kV. The knowledge and experience of Eltel Networks employees allows us to perform regular service and repairs in the shortest possible time. After each completed service, the transformer is verified and undergoes a series of tests, after which the unit is put into further use.
Installation of new transformers
Reliable operation of the transformer is directly related to correctly performed assembly work. Regardless of the type of unit selected, the basic installation steps are similar. Visual inspection of the transformer before installation allows you to identify mechanical damage and check for oil leaks. The method of transport is important, followed by the preparation of the site, the positioning of the unit and the final connection to the network. Assembly work and necessary tests are performed taking into account applicable standards and regulations. This guarantees operational efficiency, reduces costs and allows for failure-free use of power energy.
On-site infrastructure inspections
The location where the unit will be placed must meet certain requirements. This usually applies to specially prepared foundation places called oil pans, suspensions, steel structures or distribution stations in the case of internal transformers. During the installation of the transformer, grounding is carried out within the site and, if necessary, the upper and lower voltage outflows are connected. The next stage involves setting the tap changers used to regulate the voltages flowing through the unit, as well as checking the resistance of the protective earth. Additional steps may be performed to check factors that determine the operation of the device for parallel operation.
Full measurements and diagnostic tests
The operation of power transformers while maintaining full safety and proper operation also requires carrying out a number of diagnostic tests. This means carrying out measurements and tests to eliminate various types of faults. It is possible to test transformer oil (physicochemical and chromatographic), as well as clean and paint the units. The exact time from the start of all work to the completion of assembly depends on the complexity of the transformer (it also depends on the manufacturer of the unit and the voltage for which it was prepared) and the requirements of investors.
Detailed scope of infrastructure analysis
Full measurements and tests of the units concern such issues as winding resistance, insulation resistance of windings and bushings, magnetizing currents, capacitance and dielectric loss factor of windings and bushings. Mechanical deformation of windings is also tested using the SFRA method and moisture testing of windings and bushings using the FDS method. Additionally, the analysis concern the tap changers and the measurement of the power consumed by the drive. The gear measurement and checking of the group of connections, testing of current transformers installed, and examination of the core grounding elements are performed.
Renovations and modernizations of transformers
In order to ensure appropriate energy efficiency of the facilities, advanced modernization works, renovations and expansion of existing installations are carried out. This also applies to units in current operation, including their cooling systems. Performance optimization is performed according to customer demand. The introduced solutions are constantly monitored, which allows us to improve their quality, verify work efficiency and provide employees with a friendly working environment. The implemented systems enable service while maintaining the highest standards of occupational health and safety.
Lifetime service
Eltel Networks also provides after-sales service. It is possible to perform periodic measurements and inspections of the installation. Any problems are resolved as quickly as possible. Thanks to this, the operation of power transformers can proceed without disruptions. Power outages and long-term damage to units are reduced. This is the basis for ensuring operational efficiency and maintaining transformers in full technical efficiency throughout their entire operational period.
