Overload Capacity and Protection Measures of Power Transformers

The overload capacity and protection measures of power transformers are key elements to ensure the stable operation of the power system. The following is a detailed explanation of these two aspects:

1、 Overload capacity of power transformers

1. * * Rated capacity and overload capacity * *:

-Rated capacity: refers to the maximum load that a transformer can operate continuously under standard conditions. For example, the rated capacity of a 400kW transformer is 400kW.

-Overload capacity: refers to the ability of a transformer to operate above its rated load. Usually, transformers have a load capacity that exceeds their rated capacity in a short period of time. For example, a 400kW transformer may have an overload capacity of 150% to 200%, which means it can withstand loads of 600kW to 800kW.

2. Temperature rise characteristics and cooling system:

-Temperature rise characteristics: When the transformer is overloaded, it will generate additional heat, causing the temperature to rise. Reasonable design and material selection can ensure the safe operation of transformers under a certain degree of overload.

-Cooling system: To improve overload capacity, some transformers are equipped with efficient cooling systems such as oil cooling or air cooling to reduce temperature and increase overload capacity.

2、 Protection measures for power transformers

1. Overload protection device:

-Function: Monitor the load condition of the transformer and automatically cut off the power supply when it exceeds a certain threshold to prevent damage due to overload.

-Types: including thermal relays and current limiters, etc. Thermal relays detect overload by monitoring temperature, while current limiters limit the upper limit of output current.

2. * * Temperature control system * *:

-Composition: Composed of temperature sensors and monitoring devices, real-time monitoring of transformer temperature.

-Function: When the temperature exceeds the preset value, the system will take corresponding measures, such as adjusting the cooling system or issuing an alarm.

3. * * Load Management * *:

-Regularly inspect and optimize load distribution to avoid long-term overload operation of transformers.

-Reasonably distribute the load of transformers in the power system to ensure that each transformer is utilized reasonably.

4. * * Other protective measures * *:

-Regular inspection and maintenance: including checking the cooling system, insulation materials, and connecting components to ensure they are in good working condition.

-Preventing short circuits: Install reliable short circuit protection devices to avoid damage caused by short circuits.

-Maintain good grounding and ventilation: ensure the safe operation of transformers and extend their service life.

In summary, the overload capacity and protection measures of power transformers are key to ensuring the safe and stable operation of the power system. By designing and configuring overload protection devices, as well as effective temperature control and load management, the reliability and stability of transformers can be significantly improved.