S11-MD Underground Transformer
The underground transform is a kind of distribution transformer or combined transformer which can be installed in a silo； it is a compactly combined distribution facility where the transformer, high voltage load switch and protection fuse etc., can be installed in the oil tank. Reference Standard: JB/T 10544-2006,
The underground transformer can be both used for high voltage power supplying system with long-distance, small-load characteristics in projects like road, bridge, tunnels, etc., and used as combined transformers for projects where overhead lines are wired below the earth as well as for residential community power supply.
It is widely used for power supply with high reliability and free of impact to the surrounding environment. Three sets of 50Hz underground power supply and distribution network with voltage class 10kV and below can be used for power distribution and lighting in places of urban trunk roads, airports, large-scale bridges, tunnels, large-scale Greenland or parks, etc.
The prefabricated underground transformer box-type substation is a complete set of equipment combined with a light box style switch cabinet and prefabricated silo, which was preinstalled and has passed testing in factory. The product is made up of two parts of equipment both under and above the ground. The part below ground include a prefabricated (or concrete casting on site) silo and an underground transformer. The part above the ground include a light box style (or traditional) outdoor swith facility and ventilation passages. The product is suitable for a high variety of urban power distribution systems, especially civil construction power auxiliary projects like underground cable remolding.
Landscape Underground Box-type Transformer is a product developed and manufactured independently by our company. It is a novel transformer made up of underground combined transformer, outdoor high-low voltage cabinet, light-box style protection case and prefabricated underground transformer. This transformer could be tailor-made according to environmental features to achieve a good blend to the surroundings and beautify the environment.
♦ Less land occupation without occupying surface area, good landscape effect and simple installation.
♦ Realizing the approach of installation near the center of load and decentralized power supply, saving the number of low-voltage cables and investment, reducing loss on wires to ensure an economic running.
♦ Protection grade IP68, anti-explosion, able to run fully immersed in the water for a certain period of time and effective improve the reliability of power supply systems.
♦ The oil tank employs a full-insulating, fully sealed and fully welded structure, tolerable to 70kPa pressure without leaking or deformation to effectively improve the comprehensive mechanical performances of the oil tank; no need for insulation distance and able to ensure personnel safety; employs unique radiator to ensure the mechanical strength and cooling capacity of the radiator.
♦ High/low cable connection can employ the following modes:
1.Insert three phases simultaneously onto the three phase cable connector inside the transformer and onto the special-mode cable joints (applicable to three-phase underground transformer with voltage class as 10kV and below, capacity as 400kVA and below)
2.Employ single-phase cable connector and elbow-type pluggable terminal block (applicable to three-phase underground transformer with voltage class as 10kV and below, capacity as 1600kVA and below).
3.A type of patent insulating liquid is filled inside the connector to separate the insulating liquid from the transformer and ensure normal running in case of water seepage due to the capillary phenomenon.
♦ Can be equipped with oil-immersed load switch to realize opening and closing operations on load and to realize the ring network and terminal power supplies, convenient to switch between the two methods which improves the reliability of power supply.
♦ The light box style switch cabinet of prefabricated underground transformer is easy to install and appealing to viewers for its advanced exteriors, in addition, the plane advertisement of the light box can also yield good economic benefits.
♦ The prefabricated buried transformer case employs natural ventilation; an integrated temperature rise design is performed in consideration of the transformer, silo and light box. The temperature rise value for the transformer running on rated load in the silo meets the requirements of standard GB 1094.2.
♦ An automatic drain system can be installed for the silo, in special cases of flood, etc., it will automatically initialize the drainage devices
(1)power supply: 100V~260V AC/DC, 50Hz
(2)analogue: 2-channel 0~220V voltage input, 1 channel 0~5A current input, 1-channel platinum resistance fuel input;
(3)switch: Max 20 group switch quantity input, the largest 6-channel digital output;
(4)measuring accuracy: 0.5;
(5)the interference level: meets the requirements of IEC610004:1995 IV.
(1) Is within the rated load current, with or without drastic changes, the operating voltage is normal;
(2) The oil level, oil color, oil temperature exceeds the permitted value, there is no oil leakage phenomenon;
(3) Ceramic casing is clean and there are no cracks, damage or stains, discharge, whether the Terminal has color, contact overheating;
(4) Wet silicone is a saturated color, SVR running sound is normal;
(5) Is there air in the gas relay, filled with oil, the oil level gauge whether glass has broken;
(6) The SVR shell, arrestor grounding is good, oil valve is working correctly.
(1) Performance indicators such as oil analysis pressure once every three years;
(2) The insulation resistance is not less than the original value of 70%, the DC resistance of windings at the same temperature, the phase difference between the average is less than 2%, and compared with the results of previous measurements should not be more than 2%;
(3) Power failure cleaning and inspection cycle, determined according to the surrounding environment and loading conditions, generally six months to one year; main contents are: removal of deficiencies found during an inspection, the porcelain bushing shell cleaned, broken or aging pads replaced, tighten connection points check, oil fill oil, respirator silicone check replacement;
(4) Operation and maintenance of on-load tap-changer:
A number, tap years total action in 5,000 or average movements at around 14 times the number of days per year should take the tap switch box oil pressure test; tap action frequently is recommended every six months to take tap the oil in the tank pressure test;
B, running the on-load tap-changer insulating oil Breakdown voltage is less than 25kV, oil filter or replace the tap should be the insulating oil in the tank.
A,The body of oil:
1.using clean cloth, wipe clean parts of the oil;
2.carefully observe the bushing, pressure relief valve, oil level gauge, temperature sensor and whether the transport screw loosening caused by vibration;
3.fastening parts.
B,After the transmission controller without display:
1.power switch is not turned on, open;
2.power source fuse or fuse fuse, replace (2A/250V, spare parts inside the control box);
3.the secondary connector is loose, check and tighten.
Technical Data Of Three-phase Duplex Winding Power Transformer On-load Changer
