Name: voltage regulation in generators and wind turbines
Uploaded: 2024-11-21T14:54:38.000Z
Duration: 1 min 21 s
Channel: JoVE

In synchronous generators, the exciter delivers DC power to the rotor&#39;s field winding.
Older models use a rotor-driven DC generator as the exciter, while modern ones use static or brushless exciters.
Static exciters rectify AC power from the generator terminals or bus and supply it to the rotor.
Brushless exciters use an inverted synchronous generator, rectifying AC power from armature windings to the field winding.
Type 1 exciters have a shaft-driven DC generator and a voltage regulator that adjusts the field current based on the terminal voltage.
In wind turbines, voltage control varies by exciter type. Type 1 lacks direct control, while Type 2 uses resistance control to maintain constant power output during wind gusts.
Type 3 exciters control reactive power, keeping it constant or varying with real power output.
Block diagrams visualize generator-voltage control in transient stability programs.
High-gain, fast-responding exciters increase field voltage during short circuits, improving transient stability.
Block diagram equations compute the transient response.

generator voltage control

Generator Voltage Control

Generator voltage control is crucial for maintaining the stable operation of synchronous generators and wind turbines. In older models, a DC generator driven by the rotor delivers DC power to the rotor's field winding, and the power is transferred through slip rings and brushes. In the latest models, static or brushless exciters are used. Static exciters rectify AC power from the generator terminals and then transfer the DC power directly to the rotor. Brushless exciters, on the other hand, use an inverted synchronous generator in which AC power is obtained from armature windings and rectified via diodes mounted on the rotor, eliminating the need for slip rings and brushes.
The block diagram provides a standardized method for visualizing generator voltage control systems. The IEEE Type 1 exciter uses a shaft-driven DC generator to create the field current, with a voltage regulator that adjusts the field current based on terminal voltage measurements.
<img alt="Voltage regulator block diagram; feedback loop; control algorithm; equations: 1/(1+sTf), sKf/(1+sTf)." src="/files/ftp_upload/16172/16172_PT_figure_001.svg" style="height: 150px;" data-altupdatedat="1762173717000" data-alt="Figure1" />
In the block diagram, terminal voltage, Vt is measured and compared with a reference voltage Vref. The difference between these two is used to adjust the field voltage. The voltage regulator processes the voltage error with a gain (Ka) and time constant (Ta). The output of the voltage regulator is the field voltage applied to the generator's field winding, which adjusts the terminal voltage. These models represent the exciter and generator dynamics, providing a clear method for analyzing and improving stability.
Type 1 wind turbines employ squirrel cage induction machines without direct voltage regulation. Type 2 systems utilize wound rotor induction machines with adjustable external resistance, modeled as an exciter, to maintain consistent power output despite wind speed variations. Type 3 and Type 4 configurations manage both real and reactive power. Generator voltage control involves methodologies to ensure the stable and reliable operation of synchronous generators and modern wind turbines.

In synchronous generators, the exciter delivers DC power to the rotor&#39;s field winding.
Older models use a rotor-driven DC generator as the exciter, ...

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Electrical Engineering

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Transient Stability and System Controls

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voltage regulation in generators and wind turbines

Generator voltage regulation helps keep synchronous generators and wind turbines working stably. Older systems use a DC generator driven by the rotor to supply DC power to the rotor field winding. That power is passed through slip rings and brushes.

Newer systems use static exciters or brushless exciters. A static exciter rectifies AC power from the generator terminals and sends DC power directly to the rotor. A brushless exciter uses an inverted synchronous generator, takes AC power from armature windings, and rectifies it with diodes mounted on the rotor. This design removes the need for slip rings and brushes.

A block diagram is often used to show how generator voltage control works in a standard way. The IEEE Type 1 exciter uses a shaft-driven DC generator to produce field current. A voltage regulator then adjusts that current based on the measured terminal voltage. In the diagram, terminal voltage, Vt, is compared with a reference voltage, Vref, and the difference is used to adjust field voltage.

The voltage regulator processes the voltage error with a gain, Ka, and a time constant, Ta. Its output is the field voltage applied to the generator field winding, which changes the terminal voltage. These models describe exciter and generator dynamics and help engineers analyze and improve stability.

Wind turbines use related control ideas in different machine types. Type 1 turbines use squirrel cage induction machines and do not have direct voltage regulation. Type 2 systems use wound rotor induction machines with adjustable external resistance, modeled as an exciter, to help keep power output steady when wind speed changes. Type 3 and Type 4 configurations manage both real and reactive power.

Voltage Regulation in Generators and Wind Turbines

voltage-regulation-in-generators-and-wind-turbines

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simplified synchronous machine model

Transient Stability in Synchronous Generators

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Wind Turbine Types and Generator Control

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Generator voltage regulation helps keep synchronous generators and wind turbines working stably. Older systems use a DC generator driven by the rotor to supply DC power to the rotor field winding. That power is passed through slip rings and brushes. Newer systems use static exciters or brushless exciters. A static exciter rectifies AC power from the generator terminals and sends DC power directly to the rotor. A brushless exciter uses an inverted synchronous generator, takes AC power from...

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How Turbine Governors Stabilize Power Output

Turbine-governor control helps keep generator frequency and rotor speed stable when electrical load changes. It does this by matching turbine mechanical power with the power demand on the system. In a power grid, that balance is important for steady operation. Turbine-generator units also store kinetic energy because their parts are rotating. When load increases, that stored energy is released to help meet the demand. At first, electrical torque rises while mechanical torque stays nearly...

load-frequency control

Load-frequency control in power grids

Load-frequency control keeps a power grid stable when electrical demand changes. It helps keep system frequency and power flow within acceptable limits. Turbine-governor control reduces rotor speed changes after a load shift, but a steady-state frequency error can still remain when the turbine-governor reference setting does not change. In an interconnected power system, each area agrees to export or import a scheduled amount of power through tie-lines, which are the transmission lines that...

key terms and concepts

Learn how generator voltage regulation works with static, brushless, and IEEE Type 1 exciters, plus how wind turbine types manage stable power output.

Voltage Regulation in Generators and Wind Turbines | 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 Regulation in Generators and Wind Turbines

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