Causes: Low power factor is caused by inductive loads produced from transformers, induction motors, generators and certain lighting ballasts. A significant amount of the power consumed by commercial customers is comprised of inductive loads which require current to create a magnetic field that produces the desired work. The result is an increase in reactive and apparent power and a decrease in the power factor, or efficiency of a system. The efficiency of inductive equipment and how it affects a system’s power factor will vary depending on its manufacturer, design, size, and age. Cheap or poorly designed equipment will contribute significantly to lower efficiency. Most inductive equipment has a nameplate with operating data, including its power factor at rated load.
Reactive Power: Reactive Power describes the background energy movement in an Alternating Current (AC) system arising from the production of electric and magnetic fields. Devices which store energy by virtue of a magnetic field produced by a flow of current are said to absorb reactive power; those which store energy by virtue of electric fields are said to generate reactive power.
Improving Power Factor: Power factor is improved by the addition of capacitors in parallel with the connected motor or lighting circuits and can be applied at the equipment, distribution board or at the origin of the installation. Suitably sized capacitors and capacitor banks will store, filter and regulate electrical energy at the point of connection.
Electricity Billing: Most electricity billing companies charge a penalty for using electrical energy inefficiently; this is calculated from your energy consumption. This penalty is shown on your electricity invoice under "reactive power charge" and may be reflected in other aspects of your tariff such as a higher "maximum demand" and "climate change levy". Power Factor Correction will reduce charges and savings made cover the cost of the equipment supplied, this usually takes 12 to 24 months. After the initial payback period the saving on your electricity bill will automatically translate into improved profits for your business. (The minimum constant of 0.95 must be achieved to avoid reactive power penalties).
Manufacturing Process: Production of Power Factor Correction equipment has been around for many years but the technology used has evolved considerably. Improved safety features and more durable components are just part of the evolution, equipping us with products that can cope with constant demands of modern fast moving industries.
Capacitor Ratings: Power factor correction capacitors are rated in electrical units called “VAr”. One VAr is equivalent to one volt-ampere of reactive power. VAr is the unit of measurement for indicating just how much reactive power the capacitor will supply.
Harmonic Blocking: Electrical power supply to industrial networks is nowadays polluted to the same degree as the air we breathe in major conurbations. This is due to the increasing application of non-linear loads and the high number of electrical energy consumers. In most cases it is necessary to reduce the effects of harmonic currents and one way of reducing them is to install an inductance (harmonic blocking reactor) in series with the capacitor. The blocking reactors protect the capacitors, but are not designed to eliminate the harmonics like an EMC filter. The reactor value should be calculated and designed in order to reduce the resonant frequency of the circuit to a value lower than that of the lowest harmonic in the system.
Security Of Supply: Maintaining good power quality through investment is crucial for the operation of modern industries. Voltage dips and spikes or interruptions in supply for even milliseconds can damage industrial processes and information technology equipment.