How to ensure that the transformer has a rated output voltage?

 

What is the rated output voltage of the transformer?

The rated output voltage of the transformer refers to the output voltage of the transformer under the designed ambient temperature and load conditions and at steady state. In particular, the rated output voltage is the specific relationship between the voltage applied by the primary winding and the voltage generated by the secondary winding in the no-load state when the transformer is in normal operation. This rated output voltage is usually determined during the design and manufacturing process of the transformer and is indicated on the nameplate of the transformer.

How to ensure that the transformer has a rated output voltage?

To ensure that the transformer has a rated output voltage, the key is to accurately adjust the voltage to adapt to different use needs.

Cut off the load: Before voltage regulation, the load on the transformer must be cut off to prevent the current generated in the regulation process from damaging the device ‌.

‌Adjust the tap changer: Draw a few taps in the primary coil, and change the number of turns of the coil through the tap changer. The rated voltage ‌can be obtained by turning the position of the tap-changer.

‌Measuring resistance: After adjusting the gear, it is necessary to measure the DC resistance of each phase winding to ensure the current balance between each phase. If the difference in resistance value is less than 2%, further gear adjustment is required to prevent heat caused by poor contact between moving and static contacts after the equipment is working, which damages the transformer‌.

Precautions for voltage regulation

Gradual adjustment: When you adjust the tap-changer, do so gradually to avoid excessive one-time adjustment, which may cause excessive output voltage fluctuation and affect the normal operation of the device.

Monitoring voltage: During the adjustment process, measuring tools such as voltmeters should be used to monitor the output voltage in real time to ensure that the output voltage meets the rated requirements.

Factors that affect the rated output voltage

Magnetic flux: The working principle of the transformer is based on electromagnetic induction, and the change of magnetic flux directly affects the output voltage. Therefore, the fluctuation of the input voltage will directly affect the magnetic flux change of the transformer, and then affect the output voltage.

Core loss: The permeability and hysteresis loss of the core also affect the output voltage. The higher the permeability of the core, the smaller the hysteresis loss and the better the stability of the output voltage.

Load current: The load current consumes the electrical energy in the transformer, causing the output voltage to drop. The higher the load current, the faster the output voltage drops.

Working temperature: The transformer will generate heat during the working process. If the temperature is too high, it will affect the stability of the transformer output voltage. Therefore, maintaining the normal operating temperature of the transformer is very important for the stability of the output voltage.