Box-type substation development and the future

1 the development of the box-type substation

　　Box type substation is also called the outdoor substations, there are also called combined substation, it is the development in the 70 s and 1960 s Europe and the United States and other western developed countries launched a new type of outdoor unit substation substation equipment, because it has a combination of flexible and convenient for transportation, migration, easy installation, short construction period, the advantages of low operating cost, no pollution, free maintenance, brought to the attention of the electricity workers around the world.Into the mid - 1990 - s, domestic began to appear simple box-type substation, power division also formulated the ministerial standard accordingly, but is not widely used, to the late 90 s, especially after retrofit project launch, scientific research and development, manufacturing technology and scale have entered the high speed development, are widely used in urban and rural 10 ~ 110 kv variable (match) power stations, factories and mines and flow of small and medium-sized operation in transformer substation construction and retrofit, due to its easy to deep into load centers, reduce power supply radius and improve the quality of the terminal voltage, especially suitable for rural power grids transform, known as the ideal target of the construction of the substation mode in the 21st century.

　　2 the characteristics of the box-type substation

　　Box-type substation is mainly composed of multi loop high voltage switch system, armoured bus and transformer substation integrated automation system, communication, remote, measuring, and dc power electrical capacitance compensation unit combination and become, installed in a moisture, rust, dust and rodents, thermal insulation, fire prevention, guard against theft, the case closed, movable steel structure, mechanical and electrical integration, closed operation, mainly has the following features:

　　(1) advanced technology safe and reliable:

　　Body part adopts the current domestic leading technology and craft, shell generally adopts aluminium zinc steel plate, frame with a standard container material and production process, good anti-corrosion performance, guarantee the 20 years does not rust, photosensitive plate adopts aluminium alloy gusset plate, sandwich fireproof insulation materials, the casing installation of air conditioning and dehumidification equipment, equipment operation is not affected by natural climate environment and pollution of the outside world, can guarantee in 40 ℃ and 40 ℃ ~ under the conditions of normal operation.

　　The casing a equipment adopts closed high-pressure ring (load) switchgear, dry type transformer, dry type transformer, vacuum circuit breaker, spring operating mechanism, rotating isolating switch, such as domestic leading technology equipment, products with no exposed live parts, is fully enclosed, the insulation structure, completely can achieve zero accident getting an electric shock, total station can realize oil-free operation, high safety, two by microcomputer integrated automation system, which can realize the unattended.

　　(2) high degree of automation:

　　Total station intelligent design, protection system adopts microcomputer integrated substation automation equipment, installation, which can realize the four remote, namely, telemetry, remote communication, remote control, remote regulating, each unit shall be independent operation function, protection function is all ready, can be set up the operation parameters of the distance, to control the casing humidity, temperature and distance of smoke alarm, meet the requirements of the unattended.Also can realize remote monitoring image according to need.

　　(3) the factory:

　　Design, as long as the designer according to the actual requirements of substation, make a design of the main wiring diagram and the box outside equipment, can select box change specifications provided by the manufacturer and model, all the equipment installation and commissioning of plant a qualified, real factory substation construction, shorten the design and manufacturing cycle;Installation only body positioning, body contact between the cable and wire cable connection, check protection setting, transmission test and other work need to debug the whole substation from installation to put into operation only about five to eight days, greatly shorten the construction period.

　　(4) flexible combination:

　　Box-type substation because the structure is compact, and each box is constitute an independent system, which makes flexible in combination, on the one hand, we can all adopt the box type, that is to say, 35 kv and 10 kv equipment installed in the cabinet, all of the box-type substation;Also can be in only 10 kv switch box, 35 kv outdoor equipment installation, including 10 kv equipment and control system installed in the cabinet, for this kind of combination, especially suitable for retrofit of old station transformation, namely the original 35 kv equipment, only install a 10 kv switch box can meet the requirements of unattended.In a word, the combination of the box-type substation has no fixed pattern, use the unit can be free combination some patterns according to actual condition, to meet the needs of safe operation.

　　(5) investment quick effect:

　　Box-type substation investment compared with conventional substation reduce 40% ~ 50%, with 35 kv substation main transformer of 4000 kva size calculation, civil engineering (including land cost) box-type substation than conventional substation to save more than 100 100 yuan;If from the perspective of the completed and conservative estimates calculated at each station operation of 4 months in advance, and average load of up to 2000 kw, sell electricity profit of 0.10 yuan/kw. J h, three months can increase the net profit more than 60, ten thousand yuan;From the perspective of the operation in the box-type substation, due to the selection of advanced equipment, especially the oilless equipment operation, fundamentally solve the problem of leakage of equipment in conventional substation, substation can implement the state overhaul, reducing maintenance workload, can save running maintenance costs about 100000 yuan a year, the overall economic benefit is very considerable.

　　(6) cover an area of an area small,

　　With 4000 kva single scale of main transformer substation as an example, the construction of a conventional 35 kv substation, about covers an area of about 3000 m2, and the need for large-scale civil engineering;And selects the box-type substation, the main transformer box and switch box, box covers an area of minimum to 100 m2, including 35 kv the other equipment covers an area of 300 m2, maximum for substation with scale covers an area of only 1/10, can make full use of the street corner, square and factory can be installed and put into operation, in accordance with national saving land policy.

　　(7) beautiful appearance, easy and environmental coordination:

　　Body shell adopts aluminium zinc steel plate and container manufacturing technology, design aesthetics, under the premise that guarantee the power supply reliability, by selecting the box-type substation shell color, thus easy to co-ordinate with surroundings, especially suitable for urban construction, such as: urban residential district, railway stations, ports, airports, parks, green belts, such as densely populated areas, it can be used as stationary substation, also can be used as mobile substation, have the effect that adorn and beautify the environment.

　　3 35 kv container type transformer substation

　　High voltage transformer substations of 35 kv of container equipment all focused on the four sets of the container, arrange a glyph, garden layout, is very spectacular, from left to right in turn of 35 kv switch box, the main transformer box, 10 kv switch box (with control), 10 kv switch box (with compensation capacitor), main transformer box and switch box with capacitor box top structure of interlayer monitor, lower part has into the outlet box, in place to ensure that electrical equipment ventilation cooling;35 kv high voltage circuit breaker is chosen VS1-12 handcart type vacuum circuit breaker, 10 kv high-voltage switchgear choose XGN switchgear, main transformer, the transformer, voltage transformer adopts dry equipment, the comprehensive realization running without oil, fundamentally avoids blackouts caused by leakage of equipment maintenance.The casing equipped with smoke alarm system and remote image monitoring system, the alarm signal and image uploaded to scheduling by 24 h monitoring, can prevent the spread of fire, explosion and other accidents and, in addition also has rainproof, dustproof, and small animals to enter, and other protective measures.

　　Two devices using dsa microcomputer protection control system, scattered layout, the system sets protection, remote control, remote sensing, remote communication, and other functions into an organic whole, protection and control current input respectively, gear case mould pressing, use the whole board has compact structure, good sealing, anti-interference and aseismatic ability etc.On the software design, protection module and other modules are completely separate, large screen display accident report, alarm information and remote communication, remote sensing information, setting fixed value is simple, reliable and has a perfect system of self-inspection, protection, monitoring, reliable and has a black box functions, reached the domestic leading level.The selection of the above equipment make power greatly improve the degree of automation, but also reduces the operation maintenance cost, meet the needs of the development of electric power.

　　Box-type substation and the prospect of the application of 4

　　In recent years, box-type substation, it is the current and the direction of the main substation construction of the rural electric reform, but in some ways, there are some deficiencies, specific displays in:

　　(1) the fire problem: box-type substation general sealing unattended operation for the whole, although all equipment is oil-free operation and is equipped with the distance the smoke alarm system, but still exists the casing fire hazards, such as: cable, compensating capacitor, etc., once the emergency fire, is not conducive to ventilation, also does not favor the fire fighting, so should consider to design automatic fire extinguishing system, but it will increase the manufacture cost of box-type substation.

　　(2) expansion problem: box-type substation, due to the limitation of the volume and the manufacturing cost for interval extension of the margin is small, if you want to add 1 ~ 2 in the original box line spacing is relatively difficult, must add body to do it.

　　(3) maintenance problem: as the box-type substation consider manufacturing costs when making and cabinet volume, make the box-type substation maintenance space is small, is not conducive to equipment maintenance, especially the accident repair, this is the deficiency of the box-type substation, is unable to overcome the shortcomings.

　　Anyhow, looking forward to the future, box-type substation in our country the urban, rural, industrial and mining enterprises, will be widely used in public buildings, it will be for its advantages of inexpensive is used by more and more people to make our country's power grid operation level to a new step