How to calculate the current of a 100 KVA transformer with a rating of 11kV/433V.

 

I = (KVA x 1000) / (√3 x V)

 

where:

I = current in amperes

KVA = apparent power rating of the transformer in kilovolt-amperes (100 KVA in this case)

V = rated voltage of the transformer (433V in this case)

√3 = square root of 3 (1.732)

 

For a 11kV/433V transformer, we need to determine the primary current and the secondary current separately.

 

Primary Current:

The primary voltage is 11kV. Assuming a three-phase connection, we can calculate the primary current as follows:

 

I1 = (KVA x 1000) / (√3 x V1)

where:

I1 = primary current in amperes

KVA = apparent power rating of the transformer in kilovolt-amperes (100 KVA in this case)

V1 = primary voltage of the transformer (11kV in this case)

√3 = square root of 3 (1.732)

 

Substituting these values in the formula, we get:

 

I1 = (100 x 1000) / (1.732 x 11000) = 5.46 amperes (approximately)

 

Therefore, the primary current of the 100 KVA transformer with a rating of 11kV/433V is approximately 5.46 amperes.

 

Secondary Current:

The secondary voltage is 433V. We can calculate the secondary current as follows:

 

I2 = (KVA x 1000) / (√3 x V2)

where:

I2 = secondary current in amperes

KVA = apparent power rating of the transformer in kilovolt-amperes (100 KVA in this case)

V2 = secondary voltage of the transformer (433V in this case)

√3 = square root of 3 (1.732)

 

Substituting these values in the formula, we get:

 

I2 = (100 x 1000) / (1.732 x 433) = 129.1 amperes (approximately)

 

Therefore, the secondary current of the 100 KVA transformer with a rating of 11kV/433V is approximately 129.1 amperes.

 

It's important to note that the actual current may vary depending on various factors such as the load, power factor, and other transformer characteristics. 

Selection of UPS

When selecting a battery for a UPS (Uninterruptible Power Supply), there are a few key factors to consider:

1. Capacity: The capacity of the battery is the most important factor to consider. The capacity is measured in Ah (Ampere hours) or VAh (Volt-Ampere hours) and determines how long the UPS can provide power to your devices during an outage.
2. Voltage: The voltage of the battery must match the voltage requirements of your UPS.
3. Type: There are different types of batteries available, including Lead Acid and Lithium-ion. Lead Acid batteries are generally more affordable, while Lithium-ion batteries tend to have a longer lifespan and require less maintenance.
4. Brand and Quality: Choose a reputable brand with a good track record of producing reliable batteries.
5. Compatibility: Make sure the battery you select is compatible with your UPS. Check the specifications of your UPS to determine the type and size of battery it requires.
6. Environment: Consider the environment in which the UPS will be used. If the UPS will be in a high temperature environment, you may need to choose a battery that is designed to operate in those conditions.

Overall, it's important to choose a battery with the right capacity, voltage, and type to ensure that your UPS can provide uninterrupted power to your devices during an outage.