Indepth Electrical engineering

Voltage Regulation of Transformers Introduction Voltage regulation is an important performance parameter of a transformer. It indicates how much the secondary terminal voltage changes as the load varies, while the primary input voltage remains constant. In simple words: 👉 Voltage Regulation = % change in secondary voltage from no-load to full-load condition. Good transformers are expected to have low voltage regulation , meaning they maintain nearly constant secondary voltage under varying load conditions. Definition of Voltage Regulation of Transformer Voltage regulation of a transformer is defined as: Voltage Regulation = V n o   l o a d − V f u l l   l o a d V n o   l o a d \text{Voltage Regulation} = \frac{V_{no\ load} - V_{full\ load}}{V_{no\ load}} Where: V n o   l o a d V_{no\ load} = Secondary terminal voltage at no load V f u l l   l o a d V_{full\ load} = Secondary terminal voltage at full load Types of Voltage Regulation ...

How to Calculate Transformer Rating for a Particular Machine Load When selecting a transformer for a machine, you cannot directly match the HP rating of the machine with the transformer rating. Transformers are rated in kVA , while machines are usually rated in HP or kW . To determine the right transformer size, we need to: Convert HP → kW Convert kW → kVA (considering power factor) Add a safety margin (20%) Select the next available standard transformer rating Flowchart: Steps to Calculate Transformer Rating Machine Rating (HP) ↓ Convert HP → kW (kW = HP × 0.746 ) ↓ Convert kW → kVA (kVA = kW ÷ PF) ↓ Apply Safety Margin (kVA × 1.2 ) ↓ Select Next Standard Transformer Rating Step 1: Convert HP into kW The standard conversion is: 1   HP = 0.746   kW 1 \, \text{HP} = 0.746 \, \text{kW} For a 150 HP machine : 150 × 0.746 = 112   kW 150 \times 0.746 = 112 \, \text{kW} Step 2: Convert kW into kVA Since the t...