Product Introduction
This product is developed by absorbing foreign technology and combining with domestic actual conditions. The whole product has the characteristics of small size, simple installation and maintenance, low noise, low loss, anti-theft, strong overload capacity, full protection, etc. It is applicable to new residential areas, green belts, parks, station hotels, construction sites, airports and other places. YB27-12 series American-style prefabricated box-type substation is applicable to 10kV loop network power supply, dual power supply or terminal power supply system as power transformation, metering, compensation control and protection device. This product complies with the following standards: GB/T17467-1998 High-voltage and low-voltage prefabricated substation, DL/T537-93 Technical conditions for ordering 6-35kV box-type substation
Product features
◇ Fully insulated, fully sealed, less maintenance and reliable guarantee of personal safety;
◇ The structure is compact, the volume is only 1/3-1/5 of the European transformer with the same capacity, and the height is low;
◇ The sub-box structure can be adopted to avoid oil pollution in the transformer oil tank;
◇ The high-voltage side adopts double-fuse full-range protection, which greatly reduces the cost:
◇ It can be used for both ring network and terminal, and the cable head can be inserted and pulled out in case of 200A load current;
◇ The box adopts honeycomb double sandwich composite plate, which has the function of heat insulation and heat dissipation;
◇ The low voltage side is equipped with an electronic phase loss protector, which can quickly break the main incoming switch when abnormal voltage occurs in the system;
◇ High-voltage side oil-immersed load switch or SF6 load switch can be upgraded electrically, laying the foundation for realizing distribution network automation.
◇ Adopt oil-immersed S9 or S11 series transformer with better performance.
Working conditions
◇ The altitude shall not exceed 1000m;
◇ Ambient temperature: - 35 ℃~+40 ℃;
◇ Relative humidity: daily average value is not more than 95%, and monthly average value is not more than 90%;
◇ Installation site: there is no fire, explosion hazard, chemical corrosive gas and well ventilated place, and the ground inclination is not more than 3 °.
Technical parameters of transformer
The selected S9 series transformer body has low loss, good overload capacity, strong short circuit resistance, and fasteners have been treated with anti-loose treatment without hanging core; S10 series and S11 series transformers with better performance can also be selected
List of technical parameters of load switch
The load switch is oil-immersed, three-phase linkage switch and spring operating mechanism; It can be opened and closed with load, and its opening and closing speed has nothing to do with the operating force. There are two station, four station T type, four station V type and other options.
Technical parameters of fuse (recommended configuration of our oil-immersed fuse)
The high voltage side of American box transformer is protected by backup protection fuse and plug-in fuse in series to provide full range of protection, with simple principle, economy and reliability; The backup protection fuse is an oil-immersed high-voltage current-limiting fuse with large breaking capacity, which can only act in case of internal failure of the transformer. The plug-in fuse is equipped with a dual-sensitive fuse, which can provide current and temperature dual protection. After the dual-sensitive fuse is fused, the fuse core can be easily replaced on site.
Box transformer structure
The box structure of the product is composed of three parts: high pressure interval, low pressure interval and oil tank interval. The high-voltage compartment includes high-voltage cable accessories, load switch, no-load tap changer, plug-in fuse, pressure relief valve, oil level gauge, oil temperature gauge and oil drain valve. The low-voltage compartment includes low-voltage bushing, low-voltage meter, circuit breaker and capacitance compensation. The oil tank bay includes transformer winding and iron core, radiator, high-voltage load switch and fuse, which are all in the oil tank. The box transformer structure can be designed into "pin" or "eye" shape according to the scheme requirements, as shown in the figure below.
Operating instructions
Operation of load switch:
There are three types of oil-immersed load switches used in American type box transformer, namely, two-position, four-position T-type and four-position V-type, depending on their functions. One of them can be selected,
The three operations are as follows:
See Figure 2 for the four-position V-type load switch. The power plate structure is a "v" structure, which is shown in the black part of the figure. "I and II" in the figure are the incoming and outgoing lines of the loop network power supply, and "T" is the high-voltage incoming line of the transformer through the backup fuse and inserted fuse. The ring network load switch switches the network with load. Four working states of load switch:
1. In the "I - II - T" position, the "I" and "II" networks are connected, and the transformer is powered; (The substation acts as a ring network)
2. In the "I-T" position, the "I" network is connected with the transformer; (Starting and ending of substation)
3. In the "Ⅱ - T" position, the "Ⅱ" network is connected with the transformer; (Starting and ending of substation)
4. In "O" position, "I and II" networks and transformers are disconnected; (All are not charged)
Insert the special operating handle into the rotary shaft of the load switch, and rotate it clockwise or counterclockwise for about 130 °. The power plate will rotate for one gear every time the load switch is operated. Switch operation example: power supply is changed from power supply "I" to power supply "II".
A. Insert the special operating handle into the switch shaft;
B. Turn the switch clockwise once, and then the "V" blade of the switch is at the "I-II-T" position; C. Turn it clockwise again, and then the "V" blade is between "II-T" to supply power to "II"; Operation completed. Operation method 2: a. Insert the special operating handle into the switch shaft; B. Turn the switch counterclockwise once, and then the "V" blade of the switch is in the "O" position:
C. Turn it counterclockwise again, and then the "V" blade is between "II-T" to supply power to "II";
The above two methods can be used to complete the conversion from power supply "I" to power supply "II", but the second method is more safe and reasonable. The power supply "I" will not be powered on again after being cut off. At the same time, if the power supply "II" fails, it will not be connected to the fault.
In the first method, dual power supply will occur. When the power supply "I" is converted to the power supply "II", if the power supply phase is different, the fault will occur.
Replacement procedure of plug-in fuse
1. Low-voltage main switch opening;
2. Opening of high-voltage load switch;
3. Pull the pressure relief valve ring to release the pressure:
4. Hook the operating hole and rotate it 90 degrees upwards;
5. 100 mm upward, stop, and then pull out all;
6. Dry with clean cotton cloth;
7. Replace the fusible core according to the following figure:
8. Quickly insert the replaced fusible core into the original hole and fasten it.
Transportation, installation and maintenance
Transportation
The ex-factory substation shall be filled with 25 # (or 45 #) transformer oil as indicated by the oil level gauge in the oil tank. During transportation and loading and unloading, it is not allowed to invert and turn over, hit the parts and shake strongly. Special attention shall be paid to the lifting and shifting of the substation. The lifting hook shall be hooked on the hook of the oil tank. The lifting shall be carried out slowly to prevent the steel wire rope from damaging the paint on the surface of the substation and even causing the center of gravity of the whole substation to shift, tilt and fall.
Installation
When the substation is installed on site, attention should be paid to the protection of the paint on the surface of the cabinet. The handle of the barometer, the oil level gauge, the thermometer, the plug-in fuse and the insulating sleeve element are not allowed to collide, crack, etc., and the screws are not loose. Clean the dust and dirt outside the substation, inside the cabinet door and on the surface of insulating sleeve. Check whether the nameplate data and product certificate of the substation are consistent with the purchase order, and check whether the documents and spare parts are missing according to the packing list. See the figure for the civil engineering drawing of the cable inlet and outlet of the substation.
maintain
The ex-factory products have been strictly assembled and adjusted, and do not need to be disassembled again during installation, so as not to affect the performance. Maintenance is limited to the following situations: sampling analysis of transformer oil is conducted once a year; If the oil level is found to be low, it should be replenished in time. The oil grade is the same as the oil in the box. After the fuse is blown, the cause should be found out. When replacing the fuse core, the specification and model should be the same as the original specification and model.
Tests before acceptance and commissioning
◇ After unpacking, check whether the documents and accessories are complete;
◇ Whether the oil level indicated by the oil level gauge meets the product requirements; Whether the tap switch is in the correct gear;
◇ Operate the load switch clockwise and counterclockwise for four times respectively, and there shall be no abnormal phenomenon such as "refusing to open and close";
◇ Measurement of DC resistance at high and low voltage sides;
◇ Measurement of transformer ratio;
◇ Measurement of insulation resistance and power-frequency withstand voltage test (80% at the time of delivery)
Factory data
◇ The manufacturer shall provide the following documents and accessories when supplying goods
◇ Delivery list
◇ Product certificate and delivery test report
◇ Operation instructions
◇ Relevant electrical drawings
◇ Description of main components
◇ Cabinet door key, operating handle and spare parts specified in the contract.
Ordering instructions
◇ The following information must be provided to our company when calculating goods:
◇ Product model and quantity;
◇ Transformer model and capacity:
◇ Transformer oil (25 #, 45 #, high ignition point oil);
◇ High and low voltage side primary wiring scheme and main component parameters;
◇ High voltage incoming cable section;
◇ Spare parts required
