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4fb9d08492 ^ Power Factor Correction Handbook (PDF), ON Semiconductor, 2007. 75 Mvar capacitor bank in a 150 kV substation . A particularly important class of non-linear loads is the millions of personal computers that typically incorporate switched-mode power supplies (SMPS) with rated output power ranging from a few watts to more than 1kW. An RMS sensing multimeter must be used to measure the actual RMS currents and voltages (and therefore apparent power). It is about 0.65 with an ordinary PSU, but PSUs with active PFC have a power factor of 0.970.99. 80 Plus power supply certification requires a power factor of 0.9 or more.. three-phase load harmonics", Power System Harmonics (PDF), Pacific Gas and Electric. ISBN978-93-80386-74-4. Reactive power extends in the direction of as it represents a purely imaginary component of AC power. The field coils are connected either directly to polyphase voltage sources or to a phase-shifting reactor if a single-phase application.
One coil, A, will be connected through a resistor and the second coil, B, through an inductor, so that the current in coil B is delayed with respect to current in A. Since the units are consistent, the power factor is by definition a dimensionless number between 1 and 1. Importance of power factor in distribution systems. Due to their very wide input voltage range, many power supplies with active PFC can automatically adjust to operate on AC power from about 100V (Japan) to 230V (Europe). ^ "SI Units Electricity and Magnetism". Non-linear loads create harmonic currents in addition to the original (fundamental frequency) AC current. It is started and connected to the electrical network. In a wye-configuration of a transformer, triplen harmonics will not create these currents, but they will result in a non-zero current in the neutral wire. A direct reading power factor meter can be made with a moving coil meter of the electrodynamic type, carrying two perpendicular coils on the moving part of the instrument. For power factor correction of high-voltage power systems or large, fluctuating industrial loads, power electronic devices such as the Static VAR compensator or STATCOM are increasingly used.