summary

This product is developed in combination with the actual situation in China. The whole product has the characteristics of small volume, simple installation and maintenance, low noise, low loss, anti-theft, strong overload capacity, full protection and so on. It is applicable to new communities, green belts, parks, stations, hotels, construction sites, airports and other places.

Yb27-12 series American prefabricated box type substation is applicable to 10kV ring network power supply, dual power supply or terminal power supply system as substation, metering, compensation control and protection devices.

Model meaning

Functions and features

◇ fully insulated, fully sealed, maintenance free and reliable to ensure 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 box type 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 plugged in and out urgently when the load current is 200A;

◇ the box adopts honeycomb double sandwich composite board, which has the function of temperature isolation and heat dissipation;

◇ an electronic phase loss protector is installed at the low-voltage side to quickly disconnect the main incoming switch in case of abnormal voltage in the system;

◇ high voltage side oil immersed load switch or SF6 load switch can be upgraded electrically, laying a foundation for distribution network automation.

◇ adopt oil immersed S9 or S11 series transformer with better performance.

Normal service conditions

◇ the altitude shall not exceed 1000m; ◇ ambient temperature: - 35 ℃ ~ + 40 ℃;

◇ relative humidity: the daily average value shall not be greater than 95%, and the monthly average value shall not be greater than 90%;

◇ installation site: a place without fire, explosion hazard, chemical corrosive gas and good ventilation, and the ground inclination angle shall not be greater than 3 °.

Technical parameters of load switch

Technical parameters of prefabricated substation

Technical parameters of transformer

S9 series transformer body is selected, with low loss, good overload capacity and strong short-circuit resistance. The fasteners are anti loose and free of hanging core; S10 series and S11 series transformers with better performance can also be selected

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 is independent of the operating force. It can be selected from two station, four station T-type, four station V-type, etc.

Main technical parameters

Technical parameters of fuse (recommended table for selection and configuration of oil immersed fuse of the company)

The high voltage side of American box transformer is provided with full range protection by backup protection fuse and plug-in fuse in series, with simple principle, economy and reliability; The backup protection fuse is an oil immersed high-voltage current limiting fuse with large breaking capacity, which acts only in case of internal fault of the transformer. The plug-in fuse is equipped with double sensitive fuse, which can provide double protection of current and temperature. After the double 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 high-pressure interval, low-pressure interval and oil tank interval. The high-voltage bay includes high-voltage cable accessories, load switch, no-load voltage regulating tap changer, plug-in fuse, pressure relief valve, oil level gauge, oil temperature gauge and oil drain valve. The low-voltage bay includes low-voltage bushing, low-voltage meter, circuit breaker and capacitor compensation. The transformer winding, iron core, radiator, high-voltage load switch and fuse in the oil tank Bay are all in the oil tank. According to the needs of the scheme, the box transformer structure can be designed into "product" type or "target" type, as shown in the figure below.

Operating instructions: operation of load switch:

The oil immersed load switch used in American box type substation has three types: two station, four station T-type and four station V-type according to its different functions. One of them can be selected. The operations of the three types are as follows:

Refer to figure 2 for four station V-type load switch. The power blade structure is "V" structure, as shown in the black part in the figure. In the figure, "L and L" are the incoming and outgoing lines of ring network power supply, and "t" is the high-voltage incoming line connected to the transformer through backup fuse and inserted fuse. The ring network load switch switches the network with load. Four working states of load switch:

1. At "L - Ⅱ - t" position, "I" and "Ⅱ" networks are connected, and the transformer is powered; (the substation acts as a ring network)

2. At the "L-T" position, "L" network is connected with the transformer; (starting terminal of substation)

3. At "Ⅱ - t" position, the "" network is connected with the transformer; (starting terminal of substation)

4. In "O" position, "L and I" networks are disconnected from the transformer; (all are not charged) insert the special operating handle into the rotating shaft of the load switch and rotate it about 130 ° clockwise or counterclockwise. Each time the load switch is operated, the power blade will rotate by one gear. For example, the power supply from power supply "L" is changed to power supply "II".

a. Insert the special operating handle into the switch shaft;

b. Turn the switch clockwise once, and the "V" blade of the switch is in the "L - Ⅱ - t" position;

c. Turn it clockwise again, and the "V" blade is between "Ⅱ - t" to supply power to "Ⅱ"; the operation is completed.

Operation method 2:

a. Insert the special operating handle into the switch shaft;

b. Turn the switch counterclockwise once, and the switch "V" blade is in "O" position:

c. Turn it counterclockwise again, and the "V" blade is between "Ⅱ - t" to supply power to "Ⅱ"; the operation is completed.

The above two methods can be used to complete the conversion from power supply "L" to power supply "II", but the second method is safer and more reasonable. After power supply "I" is cut off, it will not be transmitted again. At the same time, if power supply "II" fails, it will not cause switching failure. However, if method 1 is used, there will be dual power supply. When power supply "I" is converted to power supply "II" If the power supply phase is different, the fault is caused by other reasons.

Four station ring network load switch (T type) the working principle of four station "t" load switch is shown in Figure 3, and the principle operation is the same as that of "V" type.

Two station terminal load switch

The structure diagram is shown in Figure 4, in which "I" is connected with the high-voltage incoming terminal. During operation, the user inserts the special operating handle into the rotating shaft of the load switch, rotates "90" counterclockwise, and the load switch turns to the "open" position. The terminal load switch only cuts off the transformer branch in the terminal power supply mode, or works when replacing the fuse core of the plug-in fuse. Therefore, the terminal load switch is only in the open and closed positions, and due to its small volume, The operating force is also small, and the use and operation are very convenient. In order to reduce the oil pollution in the oil tank, it is recommended that the user disconnect the low-voltage main switch or outlet switch before operating the load switch to cut off the load at the low-voltage side.

Cable head

a. The high-voltage incoming and outgoing line of 12kV prefabricated substation adopts cable incoming and outgoing line, and the high-voltage power supply is led out of the oil tank by epoxy cast insulating sleeve. In order to facilitate the manufacturer's test and user acceptance test, the insulating sleeve itself has the ability to withstand power frequency withstand voltage and lightning impulse withstand voltage.

b. Select elbow type or T-type cable head matching with cable section, clean its internal and external surfaces and insulating sleeve surface with absolute ethanol, apply a little 7501 vacuum silicone grease on the sleeve surface, and install it according to the special installation specification of cable work area. See the attached instructions for the installation of cable head.

Replacement of plug-in fuse

The plug-in fuse is an element that can replace the fuse core externally. When replacing, first pull the button of the pressure relief valve of the upper oil tank to balance the pressure inside and outside the oil tank. In order to ensure the safety of operators and equipment, the plug-in fuse is plugged in and out when it is not loaded, so first cut off the low-voltage switch to cut off all loads on the low-voltage side, then switch the load switch to the disconnected position of power supply and transformer with the operating handle, then loosen the handle on the fuse base with the operating handle, and then rotate it for about 90 degrees to eliminate the adhesion between the sealing gasket and the outer wall, Pull out the fuse melt 70-80mm above the syncline and stay for a few seconds. After some oil on the melt flows off, pull out the melt to avoid oil dripping on other components outside the oil tank; Wipe the melt surface with clean cotton cloth, and then replace the melt core. During replacement, pay attention to the parameters indicated on the fusible core. Different parameters cannot be substituted. See figure for replacement steps. Insert the melt after replacing the fuse core into the fuse support with force. When the handle on the melt is rotated to the locked position, ensure that the washer is close to the fuse support and the handle is buckled on the boss to ensure that the substation is fully sealed without moisture. Then re close the high-voltage load switch and low-voltage switch, and then the power supply can be restored.

Because the substation is a three-phase system, whether it is backup protection fuse or plug-in fuse, when one phase melt is fused, the three-phase melt shall be replaced generally, unless it can be determined that only one phase melt passes through the fault current.

Replacement procedure of plug-in fuse

1. Opening of low-voltage main switch;

2. High voltage load switch opening;

3. Pull the pressure relief valve ring to release the pressure:

4. Hook the operating hole and rotate upward by 90 degrees;

5. 100mm 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

transport

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, loading and unloading, it is not allowed to turn upside down and overturn, impact parts and strong vibration.

When the substation is hoisted and shifted, special attention shall be paid. The lifting hook shall be hooked on the hook of the oil tank. It shall be hoisted 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.

install

When the substation is installed on site, pay attention to the protection of the paint on the cabinet surface, do not allow the handle of barometer, oil level gauge, thermometer, plug-in fuse and insulating sleeve elements 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. The civil drawing of cable incoming and outgoing lines of substation is shown in the figure.

maintain

The ex factory products have been strictly assembled and adjusted, and do not need to be disassembled during installation, so as not to affect the performance. The maintenance is limited to the following situations: sampling and analysis of transformer oil once a year;

If the oil level drops, it shall be replenished in time. The brand of oil is the same as that in the box:

After the fuse is blown, the cause shall be found out. When replacing the fuse core, it shall be noted that its specification and model shall be the same as the original specification and model.

Test before acceptance and operation ◇ after unpacking, check whether the documents and accessories are complete;

◇ whether the oil level indicated by the oil level gauge meets the product regulations; Whether the tap changer is in the correct gear;

◇ operate the load switch clockwise and counterclockwise for four times respectively, and there shall be no abnormal phenomena such as "refusing to open and close"; ◇ measurement of DC resistance at high and low voltage side;

◇ measurement of transformer transformation ratio;

◇ measurement of insulation resistance and power frequency withstand voltage test (80% at delivery).

Factory data

◇ the manufacturer shall provide the following documents and accessories when supplying

◇ delivery list

◇ product certificate and delivery test report

◇ instruction manual

◇ relevant electrical drawings

◇ instructions for main components

◇ cabinet door key, operating handle and spare parts specified in the contract.

Ordering instructions

◇ the following information shall be provided to our company during goods counting:

◇ product model and quantity;

◇ transformer model and capacity:

◇ transformer oil (25#, 45#, high ignition point oil);

◇ primary wiring scheme and main component parameters at high and low voltage side;

◇ high voltage incoming cable section;

◇ spare parts required.

Civil engineering drawing of incoming and outgoing cables of substation (yb27)

Technical requirements:

For dimensions, see combined variable actual dimensions:

The surface of concrete pedestal shall be flat, and the combined substation shall be fixed on the pedestal by pressing plate; The type of grounding bar and cable fixing support can be determined according to the actual situation;

Cable fixing frame and grounding bar shall be embedded;

The position of inlet and outlet cable holes shall be determined according to specific conditions;

After the combined transformer is installed, there must be a gap of no less than 1.5m on the front of the switch to facilitate operation; The grounding grid can be 12 galvanized round steel or 40 galvanized round steel × 4 galvanized flat copper,

The grounding resistance shall meet the requirements of the power department.