Parallel operation conditions and precautions for power transformers

The parallel operation conditions and precautions of power transformers can be summarized as follows:

1、 Parallel operation conditions

The wiring group of the transformer must be the same. This is a key condition for ensuring the safe operation of transformers in parallel. If the wiring groups are different, it may cause voltage differences and circulating currents, which can damage the transformers.

2. The transformation ratio of the transformer should be the same, allowing for a difference of ± 0.5%. This means that the rated voltage of the transformers must be consistent to ensure that there is no significant current diversion between the transformers.

3. The short-circuit voltage (impedance voltage) of the transformer should be equal, with a permissible difference of ± 10%. This condition helps ensure that the distribution of load is proportional to capacity, avoiding overloading of certain transformers.

4. It is best not to exceed a capacity ratio of 3:1 for parallel transformers to limit the difference in short-circuit voltage values and ensure more stable parallel operation.

2、 Precautions

1. Coordination of protective devices: Transformers operating in parallel must ensure the coordination of protective devices to prevent misoperation and leakage protection failure.

2. Load distribution and management: It is necessary to regularly check whether the load distribution of transformers operating in parallel is uniform to avoid overloading of certain transformers.

3. Maintenance and overhaul: The increase in the number of transformers operating in parallel will increase the difficulty of maintenance and management. Therefore, a comprehensive maintenance and repair system should be established to ensure the safe operation of transformers.

4. Operation specifications: When performing parallel or disconnection operations on transformers, the operating procedures should be strictly followed to avoid using isolation switches and drop out fuses for such operations.

In general, the parallel operation of power transformers requires certain conditions and attention to relevant operation and maintenance matters to ensure the safe, stable, and economical operation of the power system. In practical applications, it is recommended to have a professional team of electrical engineers design and maintain the electrical equipment to ensure its effectiveness and safety.