Reactive power calculation
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For example: In a power distribution system, there is a 1000 KVA/400 V transformer. The power factor of this transformer when it is operating at full load is cosφ = 0.75. Now, a reactive power compensation device needs to be installed in order to raise the power factor to 0.95. What should be the capacity of this compensation device? What is the capacity increase after installing a dynamic compensation device while keeping the load constant? If the grid transmission and load voltage drop are calculated at 5%, what is the energy savings per hour? Capacity of the compensation device before compensation = ×1000 = 350 [KVAR] Apparent current before installing the dynamic compensation device = 1000/〔0.4×√3〕 = 1443 [A] Active current before installing the dynamic compensation device = 1443×0.75 = 1082 [A] Reduction in apparent current after installing the dynamic compensation device = 1443 – 1082/0.92 = 304 [A] Increased capacity after installing the dynamic compensation device = 304×√3×0.4 = 211 [KVA] Percentage increase in capacity = 211/1000×100% = 21% Electricity saved per hour = (304 × 400 × 5% × √3 × 1) / 1000 = 11 (kWh)
You can check the relevant standards; personally, I think there might be an issue with the algorithm, as you’re using a value of cosφ = 0.75, which corresponds to full load conditions. But in actual operation, the power factor does change