This document discusses power factor correction and automatic power factor correction (APFC) systems. It explains that power factor is the ratio of active power to apparent power and can be lagging or leading. Low power factors are caused by inductive loads and non-linear loads. APFC systems use capacitors in automatic steps controlled by a microprocessor to maintain a high power factor under varying loads without manual intervention or risk of overvoltage. This improves efficiency and reduces utility penalties and equipment loading and sizes. The document provides specifications for capacitor selection and switching equipment for APFC systems.

1. Power Factor & APFC By: Ravi Shankar Singh

2. What is power factor…? Power Factor = Active Power (kW)/Apparent Power (kVA) PF≤1.0 Usually P.F is always “Lag” (Inductive) Some time P.F can be “Lead” (Capacitive).

6. Reduction in Transformer Rating Reduction in KVAR Demand Advantages of P.F Correction Reduction in KVA Demand Reduction in Line Current Reduction in Line loss Reduction in Cable / Bus-bar size Reduction in Switchgear Rating Avoid power factor penalties Reduction in KVA Demand

7. ESTIMATION OF kVAr REQUIRED for New Electrical Installations M 75 HP, (415V, 3ph, compressor pf. 0.7) 75 HP, (415V, 3ph, compressor) 20 HP, (415V, 3ph, Pump, PF =0.70 Lag) Other loads, (total of 25 Kw) 500kVA, 11kV/415V, %Impedance = 4.25% 50 kVA, (440V, 3ph, UPS) Lighting (Load 10kW) M 30 HP, (415V, 3ph, I M pf 0.7) Let us assume that the target Power Factor as desired by the Customer is 0.95. M M

15. Network With Harmonic Filters No resonance at harmonic frequencies as filter is inductive at such frequencies Harmonic currents flow towards Grid , as it offers least impedance compared to filter Predominantly fundamental current flows through Capacitors Moderate THD(V) in the Bus No harmonic overloading of Capacitors Improvement in Power Factor without Harmonic overload Non Linear Load BUS M GRID Z T Equivalent Load Impedance “Z L ” Z N L C

28. APFC

33. COMPONENTS

34. CONTROLLER

35. REACTOR DRY TYPE RESIGN EMBADED

36. Circuit Diagram

37. THYRISTER CONTROLLED VAR STATCOM