Technical parameters and requirements of dry type transforme

This paper first introduces the technical parameters of the dry-type transformer, then introduces the working environment of the dry-type transformer, and finally expounds the technical requirements of the dry-type transformer. Let's follow Xiaobian to understand it.

 

 

 

Brief introduction of dry type transformer

 

Dry type transformer is widely used in local lighting, high-rise buildings, airports, docks, CNC mechanical equipment and other places. In short, dry type transformer refers to the transformer whose core and winding are not immersed in insulating oil.

 

 

 

The cooling methods are divided into natural air cooling (an) and forced air cooling (AF). Under natural air cooling, the transformer can operate continuously for a long time under rated capacity. When forced air cooling, the output capacity of transformer can be increased by 50%. It is suitable for intermittent overload operation or emergency overload operation; because the load loss and impedance voltage increase greatly during overload, it is in non economic operation state, so it should not be in continuous overload operation for a long time.

 

1. Use frequency: 50 / 60Hz;

 

 

 

2. No load current: 4%;

 

 

 

3. The voltage withstand strength: 2000V / min without breakdown; test instrument: yz1802 voltage tester (20mA);

 

 

 

4. Insulation grade: F (special grade can be customized);

 

 

 

5. Insulation resistance: ≥ 2m ohm test instrument: zc25b-4 megger 1000 V);

 

 

 

6. Connection mode: Y / y, △ / Y0, yo / △, self coupling (optional);

 

 

 

7. Allowable temperature rise of coil: i00k;

 

 

 

8. Heat dissipation mode: natural air cooling or temperature control automatic heat dissipation;

 

 

 

9. Noise coefficient: < 30dB

 

 

 

Working environment of dry type transformer

 

1. 0 - 40 (℃), relative humidity of 70%;

 

 

 

2. Altitude: not more than 2500 m;

 

 

 

3. Avoid rain, moisture, high temperature, high heat or direct sunlight. The distance between the heat dissipation vent and the surrounding object shall be no less than 40cm;

 

 

 

4. Prevent working in places where corrosive liquid, or gas, dust, conductive fiber or metal fines are more;

 

 

 

5. Prevent working in the place of vibration or electromagnetic interference;

 

 

 

6. Avoid long-term inverted storage and transportation and avoid strong impact.

 

1. Dry type transformer body: high voltage winding adopts copper wire winding and low-voltage winding adopts copper foil winding. The coil adopts glass fiber imported epoxy resin full vacuum Yao injection, which should have very strong rigidity and mechanical strength, and has good short circuit resistance. The safety turn of high and low voltage coil should be balanced. The epoxy glass fiber mixture has the same thermal expansion coefficient as copper conductor, so as to ensure that the coil does not crack. Strong heat dissipation performance. The temperature display control system is configured to automatically display the temperature of three-phase winding of transformer. When the temperature limit is reached, the thermostat can automatically send out signals, control the start and stop of the fan, over temperature alarm and action protection, and provide 2 passive contacts for automatic opening of the exhaust fan of the substation. The iron core and all exposed metal parts shall be rust proof. The nameplate is made of stainless steel, and the important data of the transformer are marked on the nameplate according to the national standards. The shell is assembled in assembly type, assembled on site, and the shell material is made of stainless steel plate. It has 485 communication interface, which can transmit the operation status of transformer.

 

 

 

2. Dry type transformer is not over temperature under 100% load when the fan is not running; under normal operation state of fan, it is allowed to overload 50% operation, without overtemperature, alarm and trip.

 

 

 

3. No load loss of dry-type transformer: no load loss is manufactured according to the national standard standard negative error, and it shall not be positive error, and shall conform to the latest implementation standard of Shandong electric power company.

 

 

 

4. Noise index: when the fan is not running normally, the 2000kVA transformer is lower than 52ab.

 

 

 

5. Creepage ratio distance: organic material shall not be less than 20mkv, porcelain shall not be less than 18mm/kvo20, safe and clear distance of phase to ground and phase to phase air at high voltage side (live part) 2125mmo

 

 

 

6. High voltage incoming line is cable, which meets the needs of upper and lower incoming lines; low voltage outgoing line is bus duct and upper and lower outgoing line.

 

 

 

7. The front and rear of the cabinet shall be provided with access doors and inspection windows to facilitate inspection of joints of all parts.

 

 

 

8. Equipped with temperature measuring device and temperature control box; the micro switch in the control box shall be provided by the manufacturer. 24. All components shall be of reinforced insulation type products identified by "two parts".

 

 

 

9. The grounding wire terminal (10cm) shall be discharged from the appropriate position, and the other shall be painted with corresponding phase paint.

 

 

 

10. The transformer has a life of 230 years under normal working conditions and load conditions.

 

 

 

11. Other contents not mentioned shall be executed according to gb6450-86.