# Transformer Capacitor Size Calculator

To achieve ideal power factor(.99) please enter transformer capacity and current time power factor that is to be improved and then press calculate to get capacitor bank rating in kvar/mvar.

Transformer Capacitor Size Calculator

## Introduction:

Efficient electrical supply to ensure is most important work . Power transformers, being key components in power distribution networks, play a major role in this work. However, they often introduce a reactive power component that leads to power inefficiencies. To mitigate these inefficiencies, capacitors are employed to counterbalance the reactive power and improve the overall power factor. In this article, we will explore a powerful tool, the Power Transformer Capacitor Size Calculator, that employs a simple formula to calculate the required capacitor size based on the transformer’s apparent power, its power factor, and the desired target power factor.

Understanding the Power Transformer Capacitor Size Calculator:

The Power Transformer Capacitor Size Calculator leverages the formula:

kVAR_capacitor = (kVA_transformer *PF_transformer ) * (tan(acos(PF_transformer)) – tan(acos(PF_target)))

Where:

• kVAR_capacitor: The required capacitor size in kilovolt-amperes reactive (kVAR).
• kVA_transformer: The apparent power rating of the transformer in kilovolt-amperes (kVA).
• PF_transformer: The power factor of the transformer. That is current time pf.
• PF_target: The desired power factor (unity power factor in this case).

Example 1: Calculating Capacitor Size for a 5 MVA Transformer with 0.85 Power Factor

Consider a 5 MVA power transformer with a power factor of 0.85, and our target power factor is unity (PF_target = 1). To calculate the required capacitor size, we can use the formula:

kVA_transformer = 5 MVA = 5000 kVA
PF_transformer = 0.85
PF_target = 1 (unity power factor)

kVAR_capacitor = (5000 kVA *0.85 ) * (tan(acos(0.85)) – tan(acos(1)))
kVAR_capacitor ≈ 203.42 kVAR= 2.03 MVAR

The required capacitor size for the 5 MVA transformer with a power factor of 0.85 is approximately 379.42 kVAR.

Example 2: Calculating Capacitor Size for a 10 MVA Transformer with 0.85 Power Factor

Now, let’s consider a 10 MVA power transformer with a power factor of 0.92, and our target power factor is unity (PF_target = 1). To determine the required capacitor size, we can use the formula:

kVA_transformer = 10 MVA = 10000 kVA
PF_transformer = 0.85
PF_target = 1 (unity power factor)

kVAR_capacitor = (10000 kVA*0.85 ) * (tan(acos(0.92)) – tan(acos(1)))
kVAR_capacitor ≈ 406KVAR= 4.06 MVAR

The required capacitor size for the 10 MVA transformer with a power factor of 0.92 is approximately 654.52 kVAR.

## Conclusion:

The Power Transformer Capacitor Size Calculator is a valuable tool that streamlines the process of determining the necessary capacitor size for power transformers. By considering the transformer’s apparent power and its power factor, along with the desired target power factor, engineers and power system professionals can efficiently compensate for reactive power and enhance power transmission efficiency. Embracing this approach will lead to substantial energy savings, reduced losses, and an overall more sustainable power system.