Name: rms value for ac power measurement
Uploaded: 2024-07-08T13:19:51.000Z
Duration: 1 min 7 s
Channel: JoVE

Considere un circuito de CA con una fuente de voltaje periódica conectada a una resistencia.
La potencia promedio entregada a la resistencia es igual a la integral de la potencia instantánea durante un período dividido por el período.
Cuando esta resistencia está conectada a una fuente de CC, la potencia promedio que absorbe es el producto de la corriente al cuadrado y su resistencia.
Teniendo en cuenta que la potencia media suministrada por una fuente de CC a la resistencia es equivalente a la proporcionada por la corriente periódica, la corriente continua es igual al valor efectivo de la corriente periódica.
Por lo tanto, el valor efectivo de la corriente es la raíz cuadrada del promedio de los valores de corriente instantánea al cuadrado.
Del mismo modo, se puede obtener la expresión del valor efectivo del voltaje.
Para cualquier señal periódica, el valor efectivo, también conocido como valor cuadrático medio, es igual a la raíz cuadrada de la media del cuadrado de la señal periódica.
Para una corriente y voltaje sinusoidal, el valor RMS es igual al valor máximo dividido por la raíz cuadrada de dos.

valor efectivo de una forma de onda periódica

Effective Value of a Periodic Waveform

El concepto de valor efectivo, el valor cuadrático medio (RMS), es crucial para comprender los circuitos eléctricos y la entrega de energía. Esta idea surge de la necesidad de medir la efectividad de una fuente de voltaje o corriente para suministrar energía a una carga resistiva.
El valor efectivo de una corriente periódica representa la corriente continua (CC) que transmite la misma potencia promedio a una resistencia que la propia corriente periódica. Este concepto es crucial al evaluar circuitos de CA. Para determinar el valor efectivo de la corriente, se debe encontrar la corriente RMS, que es la raíz cuadrada de la media de los valores de corriente instantánea al cuadrado durante un período. Este valor RMS corresponde a la CC que entrega la misma potencia promedio que la corriente periódica cuando se aplica a una resistencia.
<img alt="Equation 1" src="/files/ftp_upload/15119/15119_Equation_1.svg" style="height: 60px;">
De manera similar, el valor efectivo del voltaje se calcula de la misma manera que la corriente. Representa el voltaje RMS, esencial para evaluar el consumo de energía en los sistemas eléctricos.
<img alt="Equation 2" src="/files/ftp_upload/15119/15119_Equation_2.svg" style="height: 60px;">
El valor RMS es un concepto fundamental, no limitado a señales sinusoidales. Para cualquier función periódica, el valor RMS se calcula encontrando el cuadrado de la función, determinando la media de los cuadrados y luego sacando la raíz cuadrada de esa media. En aplicaciones prácticas, el voltaje y la corriente a menudo se expresan en términos de sus valores RMS en lugar de valores pico. Esto se debe a que el valor promedio de una señal sinusoidal es cero, lo que hace que el valor RMS sea una métrica más útil para el análisis de potencia. Además, los voltímetros y amperímetros analógicos están diseñados para leer directamente los valores RMS de voltaje y corriente, lo que los convierte en herramientas indispensables en las mediciones de potencia.

Valor efectivo de una forma de onda periódica

Considere un circuito de CA con una fuente de voltaje periódica conectada a una resistencia.
La potencia media entregada a la resistencia es igual a la integral de la ...

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Electrical Engineering

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rms value for ac power measurement

The RMS value, or effective value, helps measure how much power a periodic voltage or current can deliver. It is the direct current, or DC, value that gives the same average power to a resistor as the periodic signal does. This idea is especially important in AC circuits.

To find the effective value of current, calculate the root mean square, or RMS, current. First square the instantaneous current values over one period. Then find the mean of those squared values and take the square root. The result is the DC current that would produce the same average power in a resistor.

The same method is used for voltage. The effective value of voltage is the RMS voltage, and it is used to judge power use in electrical systems. The RMS idea also works for any periodic function, not only sinusoidal signals.

For any periodic waveform, the RMS value comes from squaring the function, averaging the squared values, and then taking the square root. In practice, voltage and current are often given as RMS values instead of peak values. That is useful because the average value of a sinusoidal signal is zero, while the RMS value still shows its power effect.

Analog voltmeters and ammeters are designed to read RMS values directly. That makes them useful tools for measuring voltage and current in power circuits.

RMS Value for AC Power Measurement

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effective value of a periodic waveform

The RMS value, or effective value, helps measure how much power a periodic voltage or current can deliver. It is the direct current, or DC, value that gives the same average power to a resistor as the periodic signal does. This idea is especially important in AC circuits. To find the effective value of current, calculate the root mean square, or RMS, current. First square the instantaneous current values over one period. Then find the mean of those squared values and take the square root. The...

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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 RMS, or effective value, compares AC voltage and current to DC power in resistive loads, and why it is used in electrical measurements.

RMS Value for AC Power Measurement | 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

RMS Value for AC Power Measurement

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