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

전력 흐름을 제어하려면 발전기의 원동기 및 여기 제어, 션트 커패시터 뱅크, 반응기, 정적 var 시스템 및 조정 변압기와 같은 구성 요소를 관리해야 합니다.
정상 상태 조건의 발전기는 단자 전압, 여기 전압, 전력 각도 및 동기 리액턴스를 포함한 Thévenin 등가물로 표시됩니다.
그런 다음 발전기의 전류, 실제 및 무효 전력이 계산됩니다.
전력 각도를 높이면 실제 전력은 증가하지만 무효 전력은 감소하는 반면, 여기 전압을 높이면 무효 전력이 증가하고 전력 각도가 약간 감소합니다.
버스에 션트 커패시터 뱅크를 추가하면 전압이 증가하는 반면 션트 리액터는 전압을 감소시킵니다.
탭 변경 및 전압 조정 변압기는 버스 전압과 무효 전력 흐름을 제어합니다. 위상각 조절 변압기는 버스 각도와 실제 전력 흐름을 제어합니다.
탭 설정 또는 전압 조정의 변경은 전력 흐름 프로그램에 의해 계산된 변압기의 권선비를 변경합니다.
이 프로그램은 또한 스위칭 라인, 변압기, 부하 및 발전기의 영향을 평가합니다. 향후 부하 증가에 맞게 변경 사항을 시뮬레이션합니다.

전력 흐름 제어

전력 흐름 제어

전력 시스템에서 전력 흐름을 제어하는 ​​방법에는 여러 가지가 있습니다.

<ul style="list-style-type: disc; display: flex; flex-direction: column; gap: 10px; padding: 0 0 0 40px;">
 <li>발전기의 원동기 및 여자 제어</li>
 <li>션트 축전기 뱅크, 션트 리액터 및 정적 바 시스템 스위칭</li>
 <li>탭 변경 및 조절 변압기 제어</li>
</ul>

시스템의 간단한 발전기는 균형 잡힌 정상 상태 조건에서 작동하는 모델을 나타내는 테브난 등가 회로로 표현됩니다. 주요 매개변수에는 발전기 단자 전압 V_t, 여자 전압 E_g, 전력 각도 δ 및 정순 동기 반응저항 X_g가 포함됩니다.

<img alt="Figure1" src="/files/ftp_upload/16150/16150_PT_Image_1.svg" style="height: 36px;">

발전기 전류는 다음과 같습니다.

<img alt="Equation1" src="/files/ftp_upload/16150/16150_PT_equation_1.svg" style="height: 160px;">

전달되는 복소 전력은 다음과 같습니다.

<img alt="Equation2" src="/files/ftp_upload/16150/16150_PT_equation_2.svg" style="height: 36px;">

전력 시스템 버스에 추가된 션트 축전기 뱅크는 버스 전압 크기를 증가시키고 무효 전력을 보상합니다. 이 조정은 음의 무효 전력을 흡수하는 축전기를 연결하여 모델링되므로 시스템의 전체 무효 전력 수요를 줄일 수 있습니다. 또한 탭 변환 변압기는 권선비를 조정하여 버스 전압을 조절하고 무효 전력 흐름을 관리하는 데 사용되므로 네트워크의 전압 및 무효 전력 프로파일에 영향을 미칩니다. 이 조정은 시스템 안정성과 효율성을 유지하고 부하 변동을 수용하며 전력 공급을 개선하는 데 도움이 됩니다.

전력 흐름 연구는 종종 시행착오를 사용하여 발전 수준과 제어 설정을 조정합니다. 이러한 조정을 통해 시스템이 원하는 장비 부하 및 전압 프로파일을 충족하고 부하 증가, 새로운 송전, 변압기 및 발전에 대비할 수 있습니다. 전력 흐름 제어는 시스템 안정성, 효율성 및 신뢰성을 유지하기 위한 다양한 방법과 조정을 포함하는 동적 과정입니다.

전력 흐름을 제어하려면 발전기의 원동기 및 여기 제어, 션트 커패시터 뱅크, 반응기, 정적 변수 등과 같은 구성 요소를 관리해야 합니다.

Education

교육

JoVE Core

Electrical Engineering

전기공학

Unit 1

제1단원

Steady-State Transmission Lines and Power Flows

정상 상태 송전선로 및 전력 조류

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

KEY TERMS AND CONCEPTS

주요 용어 및 개념

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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