Overview
110kV, 220kV is the main voltage level of the power supply network, due to the high voltage, the neutral point is generally directly grounded, due to the requirements of relay protection setting configuration and prevention of communication interference, in order to limit the single-phase short-circuit current, some transformers adopt the neutral point is not grounded. In this mode of operation, due to lightning strikes, single-phase grounding short circuit faults, etc., will cause overvoltage at the neutral point, and most of the transformers are graded insulation, so the overvoltage poses a great threat to the insulation of the neutral point, and protection devices must be set up to prevent accidents.
GEDQ-ZCB-110/220 series transformer neutral point complete set of equipment is manufactured in strict accordance with the relevant provisions of DL/T620-1997 "Overvoltage Protection and Insulation Coordination of AC Electrical Installations" on the use of gap protection for transformers in 110kV/220 kV effective grounding power grid, and in accordance with GB311.1-1997 "Insulation Coordination of High-voltage Transmission and Transformation Equipment" and "Eighteen Major Anti-accident Measures for Power Grid" published by the State Grid Corporation of China in June 2005The technical requirements for the prevention of grounding grids and overvoltage accidents are designed. It is suitable for neutral point overvoltage protection of ungrounded transformers in 110kV and 220kV effective grounded power grids.
In order to make the transformer neutral point equipment in 110kV and 220 kV substations reliable, easy to install, debug and operate, and simple and beautiful layout, Juyi Electric has also launched a complete set of transformer neutral point equipment integrating transformer neutral point rod gap, gap current transformer, isolation switch, lightning arrester, terminal box and mounting bracket and other electrical equipment.
The user can choose the neutral point overvoltage protection scheme of the transformer with pure clearance, or the scheme of parallel connection between the gap and the arrester for collaborative protection. The arrester and the disconnector can be flexibly combined according to the needs of the project. The operating mechanism of the disconnector can be selected manual or electric. The electrical and mechanical properties of the product are fully debugged and tested before leaving the factory, and it can also be easily recalibrated at the use site.
Environmental Conditions
2.1 Suitable for indoor and outdoor use;
2.2 Ambient temperature: not lower than -50°C, not higher than +50°C;
2.3 Relative humidity: not more than 95% (25°C);
2.4 Altitude: no more than 2000m, more than 2000m can be customized according to the actual situation.
2.5 Areas with a seismic intensity of 7 degrees or less; The wind speed does not exceed 35m/s;
2.6 The air in the installation site should not contain chemically corrosive gases and vapors, and there should be no explosive dust.
2.7 Not suitable for non-horizontal installation.
2.8 Grid frequency: 58~62Hz (60Hz system), 48~52Hz (50Hz system).
Performance Characteristics:
3.1 The current transformer is directly connected to the bar gap;
3.2 The gap discharge voltage is stable, and the gap distance is easy to adjust;
3.3 The use of stainless steel finishing electricity, the surface is not easy to corrode;
3.4 The mounting bracket adopts on-site welding-free design technology to effectively solve the anti-corrosion problem of outdoor products;
3.5 The gap combination equipment base installation eye, the whole piece of transportation and hoisting, on-site installation is fast and convenient;
3.6 Full range and full specifications, suitable for the requirements of different regions and different users.