The relationship between the capacity and power of a grounding transformer is also based on basic electrical principles. First of all, it needs to be made clear that a grounding voltage transformer is a special type of transformer, which is mainly used for grounding the power system to ensure the safe and stable operation of the system.

Grounding transformer cabinet and grounding resistor cabinet

1. Definition:

Capacity (kVA): The capacity of the grounding transformer refers to is the apparent power that it can continuously transmit under rated voltage and rated current. This is usually expressed in units of kVA (kilovolt amperes). Apparent power is the product of voltage and current and represents the transformer's transmission capability without considering the power factor.

Power (kW): The power of a grounding transformer refers to the active power transmitted by it under actual working conditions. This is usually expressed in kW (kilowatt) units. Active power is the power actually used to do work and is part of the apparent power.

2. Relationship:

Like conventional transformers, the relationship between the capacity and power of a grounding transformer is also affected by the power factor. Power factor (cosφ) is the ratio between active power and apparent power. It represents the efficiency of the voltage converter in transmitting electrical energy.

The capacity (S) of a grounding transformer is equal to the active power it transmits (P) divided by the power factor (cosφ). The mathematical formula is: S= P / Cosφ.

If the grounding transformer is perfectly efficient (i.e. the power factor is 1), then its capacity is equal to the active power it transmits. However, in actual situations, due to various losses, the power factor is usually less than 1, so the capacity of the grounding transformer is usually greater than the active power it transmits.

3. Practical application:

When selecting a grounding transformer, its capacity needs to be determined based on the actual needs of the system. This usually involves consideration of factors such as the system's load characteristics, power factor, and expected fault currents.

Since the grounding transformer is mainly used for system grounding protection, its capacity should be large enough to cope with possible fault currents. At the same time, in order to ensure stable operation of the system, the power factor of the grounding transformer should also be as high as possible.

In summary, the relationship between the capacity and power of a grounding transformer is affected by the power factor. When selecting and designing a grounding transformer, the actual needs and conditions of the system need to be comprehensively considered to ensure that its capacity and power can meet the requirements of the system.