Name: power factor and ac load behavior
Uploaded: 2024-07-08T13:19:54.000Z
Duration: 1 min 11 s
Channel: JoVE

El factor de potencia es la relación entre la potencia activa y la potencia aparente.
Está determinado por la diferencia de fase entre el voltaje y la corriente, que surgen debido a la presencia de elementos reactivos en el circuito.
Se puede hacer una analogía con un vaso de café, donde el café simboliza la potencia activa útil, y la espuma representa la potencia reactiva, que, a pesar de no realizar un trabajo real, se utiliza en ciertos electrodomésticos.
El costo cubre todo el vaso. Para obtener el valor máximo, la potencia reactiva debe reducirse para acercar el factor de potencia a la unidad.
Para una carga puramente resistiva, el voltaje y la corriente en fase producen un factor de potencia unitario, donde la potencia aparente es igual a la potencia activa.
Para una carga puramente reactiva, el factor de potencia es cero, lo que implica que la potencia activa es cero.
Entre estos extremos, el factor de potencia es líder o rezagado. Un factor de potencia principal indica que la corriente lidera el voltaje, lo que implica una carga capacitiva.
Un factor de potencia rezagado significa que la corriente se retrasa con respecto al voltaje, lo que indica una carga inductiva.

factor de potencia

El factor de potencia se define como la relación entre la potencia promedio (o activa) y la potencia aparente, como lo ilustra la relación

<img alt="Equation 1" src="/files/ftp_upload/15122/15122_Equation_1.svg" style="height: 30px;">

El término entre paréntesis, (θ_v - ​​θ_i), se conoce como ángulo del factor de potencia, ya que representa el ángulo cuyo coseno produce el factor de potencia. Si V representa el voltaje a través de la carga y Ⅰ significa la corriente que fluye a través de ella, el ángulo del factor de potencia equivale al ángulo de la impedancia de la carga. Esencialmente, el factor de potencia es el coseno de la diferencia de fase entre el voltaje y la corriente, así como el coseno del ángulo de la impedancia de carga.

De la ecuación anterior, se puede inferir que el factor de potencia es el multiplicador de la potencia aparente para producir la potencia real o promedio. El valor del factor de potencia oscila entre cero y uno. Cuando se trata de una carga puramente resistiva, el voltaje y la corriente están en fase, lo que da como resultado un ángulo del factor de potencia (θ_v - ​​θ_i) = 0 y un factor de potencia = 1. Esto indica que la potencia aparente es igual a la potencia promedio. Para una carga puramente reactiva, (θ_v - ​​θ_i) = ±90o y un factor de potencia = 0, lo que hace que la potencia sea cero. Entre estos dos extremos, se dice que el factor de potencia está en adelanto o en atraso. Un factor de potencia adelantado sugiere que la corriente precede al voltaje, lo que indica una carga capacitiva, mientras que un factor de potencia retrasado sugiere que la corriente sigue al voltaje, lo que indica una carga inductiva. El factor de potencia afecta significativamente las facturas de electricidad que los consumidores pagan a sus empresas de servicios públicos.

Factor de potencia

El factor de potencia es la relación entre la potencia activa y la potencia aparente.
Está determinado por la diferencia de fase entre el voltaje y la corriente, que ...

Education

Educación

JoVE Core

Electrical Engineering

Ingeniería Eléctrica

Unit 1

Unidad 1

AC Steady State Power

Potencia de corriente alterna en estado estacionario

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

Power Factor

power factor and ac load behavior

Power factor describes how voltage and current behave in an AC load. It is the ratio of average, or active, power to apparent power. The power factor angle is the phase difference between voltage and current, and the cosine of that angle gives the power factor. It also matches the angle of the load impedance.

Power factor shows how much apparent power becomes real, or average, power. Its value ranges from zero to one. When a load is purely resistive, voltage and current are in phase. In that case, the power factor angle is 0 and the power factor is 1, so apparent power equals average power.

A purely reactive load gives the opposite extreme. The phase difference is ±90°, and the power factor is 0, so the power is zero. Between these limits, the power factor can be leading or lagging. A leading power factor means current leads voltage, which points to a capacitive load. A lagging power factor means current follows voltage, which points to an inductive load.

Power factor also matters in everyday electricity use. It affects the electricity bills customers pay to utility companies. Understanding it helps explain why the phase relationship between voltage and current is important in AC circuits.

Power Factor and AC Load Behavior

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AC power in series and parallel circuits follows a power preservation rule. In AC circuits, the complex power, real power, and reactive power produced by the source are equal to the total complex, real, and reactive powers absorbed by the loads. When two load impedances are connected in parallel to an AC source V, the source power can be written as the sum of the complex powers delivered to loads Z1 and Z2. If those same loads are connected in series with the voltage source, the complex power...

power factor

Power factor describes how voltage and current behave in an AC load. It is the ratio of average, or active, power to apparent power. The power factor angle is the phase difference between voltage and current, and the cosine of that angle gives the power factor. It also matches the angle of the load impedance. Power factor shows how much apparent power becomes real, or average, power. Its value ranges from zero to one. When a load is purely resistive, voltage and current are in phase. In that...

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Reducing Reactive Power in AC Loads

Power factor correction helps AC systems use electrical power more efficiently. In a factory circuit, transmitted power includes apparent power, which is made of active power and reactive power. Power factor is the ratio of real power, measured in kW, to apparent power, measured in kVA. It shows how much of the supplied power becomes useful work. A low power factor often happens when an inductive load draws too much reactive power. This creates a lagging power factor. It can also cause large...

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Power from Multiple AC Sources

Power from multiple AC sources is found by adding the effects of each source separately. In a circuit with two sinusoidal voltage sources, each source acts independently. The superposition principle says the total current is the sum of the currents produced by each source alone. If those currents are labeled i1 and i2, they combine to give the total current. Instantaneous power is the power at one moment in time. In this circuit, it equals the square of the instantaneous current times the...

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Matching Load Impedance for Maximum Power

Maximum power transfer in an AC circuit depends on matching the load impedance to the Thevenin equivalent of the source network. The load draws current, and the circuit delivers power to that load. To analyze the current, the voltages, currents, network impedance, and load impedance are written in rectangular form. The average power delivered to the load comes from the square of the current multiplied by the load resistance. To find the condition for maximum power, the power is differentiated...

key terms and concepts

Learn how power factor links voltage, current, and AC load behavior. Explore phase difference, leading and lagging loads, and why it affects electricity bills.

Power Factor and AC Load Behavior | JoVE K12

JoVE Core Electrical Engineering offers easy-to-understand animated videos that cover fundamental concepts of electric circuits along with circuit analysis techniques. It incorporates first-order and second-order circuits using operational amplifiers and circuit transformation concepts. The inclusion of practical design examples and real-world applications through scientist-in-action videos adds significant educational value, making complex concepts accessible.

electrical engineering

Power Factor and AC Load Behavior

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