Basic Functions Of Epoxy Resin Dry-Type Transformers

Dry-type transformer is an important type of transformer, and it can work without transformer oil. There are many functions of dry-type transformer.

(1) Automatic fan control: The temperature signal is measured by a Pt100 thermal temperature measuring resistor embedded in the heat of the low-voltage winding. The transformer load increases and the operating temperature rises. When the winding temperature reaches 110°C, the system automatically starts the fan to cool; when the winding temperature drops to 90°C, the system automatically stops the fan.

(2) Over-temperature alarm and trip: The winding or core temperature signal is collected through the PTC non-linear thermal temperature measuring resistor in the embedded low-voltage winding. When the temperature of the transformer winding continues to rise, if it reaches 155°C, the system will output an over-temperature alarm signal; if the temperature continues to rise to 170°C, the transformer can no longer continue to operate, and an over-temperature trip signal must be sent to the secondary protection circuit, which should make the transformer Trip quickly.

(3) Temperature display system: The temperature change value is measured by the Pt100 thermistor embedded in the low-voltage winding, and the temperature of each phase winding is directly displayed (three-phase inspection and large value display, and historical high temperature can be recorded), which can be The high temperature is output as 4-20mA analog quantity. If it needs to be transmitted to a remote computer (distance up to 1200m), a computer interface can be added. One transmitter can monitor up to 31 transformers at the same time. The over-temperature alarm and tripping of the system can also be actuated by the signal of the Pt100 thermistor, which further improves the reliability of the temperature control and protection system.