Name: voltage and reactive power control
Uploaded: 2024-11-21T14:54:26.000Z
Duration: 1 min 30 s
Channel: JoVE

El control del flujo de energía requiere la gestión de componentes como el motor principal y el control de excitación de los generadores, los bancos de condensadores de derivación, los reactores, los sistemas de var estáticos y los transformadores de regulación.
Un generador en condiciones de estado estacionario está representado por el equivalente de Thévenin, que incluye voltaje terminal, voltaje de excitación, ángulo de potencia y reactancia síncrona.
A continuación, se calculan las potencias actuales, reales y reactivas del generador.
El aumento del ángulo de potencia aumenta la potencia real pero disminuye la potencia reactiva, mientras que el aumento del voltaje de excitación aumenta la potencia reactiva y disminuye ligeramente el ángulo de potencia.
La adición de un banco de condensadores de derivación a un bus aumenta su voltaje, mientras que un reactor de derivación lo disminuye.
Los transformadores de cambio de tomas y reguladores de voltaje controlan los voltajes del bus y los flujos de potencia reactiva. Los transformadores reguladores de ángulo de fase controlan los ángulos de bus y los flujos de potencia reales.
Las alteraciones en la configuración de la toma o la regulación de voltaje alteran la relación de vueltas del transformador calculada por el programa de flujo de energía.
El programa también evalúa los efectos de las líneas de conmutación, los transformadores, las cargas y los generadores. Simula cambios para satisfacer el crecimiento futuro de la carga.

control del flujo de potencia

Existen varios métodos para controlar el flujo de potencia en los sistemas eléctricos:

<ul style="padding-left: 35px; list-style-type: disc;">
	<li>Control de excitación y motor primario de generadores</li>
	<li>Conmutación de bancos de condensadores en derivación, reactores en derivación y sistemas de VAR estáticos</li>
	<li>Control de transformadores de conmutación y regulación</li>
</ul>

Un generador simple en el sistema está representado por su circuito equivalente de Thevenin, que representa su modelo operando en condiciones de estado estable y equilibrado. Los parámetros clave incluyen la tensión terminal del generador V_t, la tensión de excitación E_g, el ángulo de potencia δ y la reactancia sincrónica de secuencia positiva X_g.

<img alt="Figure1" src="/files/ftp_upload/16150/16150_PT_Image_1.svg" style="height: 36px;">

La corriente del generador es:

<img alt="Equation1" src="/files/ftp_upload/16150/16150_PT_equation_1.svg" style="height: 160px;">

Y la potencia compleja entregada es:

<img alt="Equation2" src="/files/ftp_upload/16150/16150_PT_equation_2.svg" style="height: 36px;">

Un banco de condensadores en derivación añadido a un bus del sistema de energía aumenta la magnitud de la tensión del bus y compensa la potencia reactiva. Este ajuste se modela conectando un condensador, que absorbe la potencia reactiva negativa, reduciendo así la demanda total de potencia reactiva del sistema. Además, se utilizan transformadores de cambio de tomas para regular las tensiones del bus y gestionar los flujos de potencia reactiva ajustando la relación de vueltas, lo que influye en el perfil de voltaje y potencia reactiva en la red. Este ajuste ayuda a mantener la estabilidad y la eficiencia del sistema, adaptándose a las variaciones de carga y mejorando el suministro de energía.

Los estudios de flujo de potencia suelen utilizar el método de prueba y error para ajustar los niveles de generación y los parámetros de control. Estos ajustes garantizan que el sistema cumpla con las cargas de los equipos y los perfiles de tensión deseados, preparando la red para el crecimiento de la carga, nuevas transmisiones, transformadores y generación. El control del flujo de potencia es un proceso dinámico que implica varios métodos y ajustes para mantener la estabilidad, la eficiencia y la confiabilidad del sistema.

Control del flujo de potencia

El control del flujo de energía requiere la gestión de componentes como el motor principal y el control de excitación de los generadores, los bancos de condensadores de derivación, los reactores, la var estática ...

Education

Educación

JoVE Core

Electrical Engineering

Ingeniería Eléctrica

Unit 1

Unidad 1

Steady-State Transmission Lines and Power Flows

Líneas de transmisión en estado estacionario y flujos de potencia

steady-state-transmission-lines-and-power-flows

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

Control of Power Flow

voltage and reactive power control

Voltage and reactive power control help keep a power system stable and efficient. In this topic, generator settings, switched equipment, and transformer taps work together to guide how power moves through the network.

A generator can be modeled with a Thevenin equivalent circuit under balanced steady-state conditions. The main terms are terminal voltage Vt, excitation voltage Eg, power angle δ, and positive-sequence synchronous reactance Xg. From this model, the generator current and the complex power delivered can be determined.

One way to adjust power flow is through generator control. The prime mover and the excitation system can be changed to influence generation and voltage behavior. Power flow studies often use trial and error to set these values and other controls.

Shunt capacitor banks, shunt reactors, and static var systems are also used to manage reactive power. A shunt capacitor bank connected to a bus raises the bus voltage magnitude. It also compensates for reactive power by absorbing negative reactive power, which lowers the system’s overall reactive power demand.

Tap-changing and regulating transformers provide another way to control bus voltage and reactive power flow. By changing the turns ratio, these transformers alter the voltage profile across the network. This helps the system handle load changes and support efficient power delivery.

These control steps are used to meet equipment loading limits and desired voltage profiles. They also prepare the network for load growth, new transmission lines, transformers, and added generation. In this way, power flow control remains a dynamic process that supports stability, efficiency, and reliability.

Voltage and Reactive Power Control

transmission-line differential equations

Modeling Voltage and Current on Transmission Lines

Transmission lines carry electric power, and their resistance, inductance, and capacitance are spread out along the line. Because these properties are distributed per unit length, voltage and current change as they move from one end of the line to the other. Differential equations are used to describe that variation. A line-section model helps show how this works. In the model, a small length, Δx, is used to represent the line. Voltage V(x) and current i(x) are measured from the receiving end.

lossless lines

Lossless Lines and Voltage Behavior

Lossless transmission lines in electrical engineering are described by a purely imaginary propagation constant and a resistive characteristic impedance. Their ABCD parameters show an equivalent pi circuit with an imaginary series impedance and a shunt admittance. When the product of beta and line length is less than pi, the line has inductive series impedance and capacitive shunt admittance, which keeps it lossless. Wavelength is the physical length over which voltage or current phase changes...

maximum power flow and line loadability

Transmission Line Power Limits and Loadability

Transmission line power limits and loadability depend on voltage, angle, and line impedance. For lossy transmission lines, ABCD parameters in phasor form are used to relate sending-end and receiving-end voltages and currents. This matrix relation makes it possible to find the receiving-end current and then calculate the complex power delivered to the load. From the complex power, the real and reactive power components can be determined. For a lossless line, the equations become simpler, and...

the power flow problem and solution

Power Flow Analysis in Electric Networks

Power flow analysis helps determine how real and reactive power move through an electric network. It uses the system’s single-line diagram, which shows the buses, transmission lines, transformers, and loads. The analysis focuses on balanced three-phase steady-state operation. Each bus in the system has four key variables: voltage magnitude V k, phase angle δ k, real power P k, and reactive power Q k. Two of these four variables are treated as inputs. The power flow program solves for the...

control of power flow

Voltage and reactive power control help keep a power system stable and efficient. In this topic, generator settings, switched equipment, and transformer taps work together to guide how power moves through the network. A generator can be modeled with a Thevenin equivalent circuit under balanced steady-state conditions. The main terms are terminal voltage Vt, excitation voltage Eg, power angle δ, and positive-sequence synchronous reactance Xg. From this model, the generator current and the...

fast decoupled and dc powerflow

Power Flow Shortcuts for Grid Contingencies

Fast decoupled power flow and DC power flow give engineers faster ways to study a power system during contingencies such as generator outages or transmission line failures. These methods help operators get quick power flow solutions, which is important for real-time system adjustments. Fast decoupled power flow simplifies the Jacobian matrix, the set of equations used in power flow calculations, by neglecting some elements. The method drops J2 and J3 and assumes voltage magnitudes stay close...

key terms and concepts

Learn how generator settings, shunt capacitors, reactors, and tap-changing transformers help control voltage, reactive power, and power flow in power systems.

Voltage and Reactive Power Control | 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

Voltage and Reactive Power Control

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