Dependiendo de la estructura de la tasa de su utilidad eléctrica, usted puede poder salvar una cantidad substancial de dinero en su recibo de la luz. El período de restitución para una compra del equipo inclusive el costo de la instalación puede ser menos de seis meses a un año. La tasa de la utilidad estructura esa cuenta para el consumo reactiva del poder, por o un KVA o el uso de la demanda de var, o una pena del factor del poder es los que pueden proporcionar esto devuelven. Otros beneficios adicionales ser ganados corrigiendo el factor del poder es, las pérdidas más bajas de energía, mejor regulación del voltaje y la capacidad liberada de sistema. Esta página explica los fundamentos del factor del poder y cómo bancos de condensador de derivación de NEPSI le pueden beneficiar.

Todo equipo eléctrico requiere "vars" - un término utilizado por ingenieros de energía eléctrica de describir el poder reactiva o imantando requerido por las características inductivas del equipo eléctrico. Estas características inductivas más son pronunciadas en motores y transformadores, y por lo tanto, puede ser bastante significativo en facilidades industriales. El flujo de vars, o del poder reactiva, por un metro de vatio-hora no realizará la lectura de metro, pero el flujo de vars por el sistema del poder tendrá como resultado las pérdidas de energía en la utilidad y la facilidad industrial. Algunas utilidades cargan para estos vars en forma de una pena, o en forma de la carga de la demanda de KVA, para justificar el costo para la energía perdida y la capacidad adicional de conductor y transformador requirió a llevar el vars. Además de pérdidas de energía, el flujo de var puede causar también gota excesiva de voltaje, que puede tener que ser corregido por o la aplicación de condensadores de derivación, o de otro equipo más costoso, tal como la carga-canilla que cambia transformadores, los motores síncronos, y condensadores síncronos.

Figure 1 - Power Factor Triangle

The power triangle shown in figure 1, is the simplest way to understand the effects of reactive power. The figure illustrates the relationship of active (real) and reactive (imaginary or magnetizing) power. The active power (represented by the horizontal leg) is the actual power, or watts that produces real work. This component, is the energy transfer component, which represents fuel burned at the power plant. The reactive power, or magnetizing power, (represented by the vertical leg of the upper or lower triangle) is the power required to produce the magnetic fields to enable the real work to be done. Without magnetizing power, transformers, conductors, motors, and even resistors and capacitors would not be able to operate. Reactive power is normally supplied by generators, capacitors and synchronous motors. The longest leg of the triangle (on the upper or lower triangle), labeled total power, represents the vector sum of the reactive power and real power components. Mathematically, this is equal to:

Electric power engineers often call total power, kVA, MVA, apparent power, or complex power. Some utilities measure this total power, (usually averaged over a 15 minute load period) and charge a monthly fee or tariff for the highest fifteen minute average load reading in the month. This tariff is usually added to the energy charge or kilowatt-hour charge. This type of billing is often called kva demand billing and can be quite costly to an industrial facility. NEPSI's shunt capacitors can save your company money by decreasing your reactive power component supplied by the utility to near zero vars.

The power triangle and the equation above show, that as the reactive power component is decreased by adding shunt capacitors, the total power will also decrease. This is shown by the decreased length of the dashed lines in the power triangle as the reactive power component approaches zero. Therefore, adding capacitors, which will supply reactive power locally, can reduce your total power and monthly kva demand charge.

The angle "phi" in the power triangle is called the power factor angle and is mathematically equal to:

The ratio of the real power to the total power in the equation above (or the cos of phi) is called power factor. As the angle gets larger (caused by increasing reactive power) the power factor gets smaller. In fact, the power factor can vary from 0 to 1, and can be either inductive (lagging) or capacitive (leading). Capacitive loads are drawn down, and inductive loads are drawn up on the power triangle. Most industrials normally operate on the upper triangle (inductive or lagging triangle). As an industrial adds capacitors, the length of reactive (inductive) power leg is shortened by the number of capacitive kvar that were added. If the number of capacitive kvar added exceeds the industrials inductive kvar load, operation occurs on the lower triangle. This is commonly referred to as over compensation.

Utilities charge for reactive power in a countless number of ways. Some utilities charge for kvar demand, while others charge a strait fee for a power factor less than their target. To fully understand the benefits of NEPSI's shunt capacitor and harmonic filters, you must acquire your electric billing rate structure. This rate structure will describe how cost for poor power factor are added to your monthly bills. If you need assistance in calculating your pay-back periods, feel free to contact our nearest factory trained sales representatives or just call Northeast Power Systems, Inc.

Table 1, which contains kilowatt multipliers, can be used to calculate the amount of kvar required to raise your "original power factor" to your "desired power factor". For example, a facility has a peak kilowatt demand of 5000 kW with a power factor of 0.80. The facilities engineer wants to raise its power factor from 0.80 to 0.95. The kW multiplier obtained from table 1 is 0.421. Multiplying this value times the facilities kilowatt demand yields 2105 kvar (0.421 X 5000 = 2105). Therefore, a 2105 kvar capacitor bank would raise the facility's power factor from 0.80 to 0.95.

Table - 1 Kilowatt Multipliers

In addition to the above table, the following web page can be used to calculate the required amount of vars based upon an initial power, desired power factor, and kw demand (Calculation of Required kvar to Raise Power Factor).

Other equations and calculation methods for power factor correction exists in the formula section of this website.

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Contacto: Rodrigo Dünner

Northeast Power Systems, Inc.
66 Carey Road
Queensbury, New York 12804
Phone: 518-792-4776
Fax: 518-792-5767