Excitation systems: Generator Control & Stability

Illustration for the solution ‘Excitation systems' showing a man and a woman in front of a cabinet containing an excitation system with a reduced, shadowy and abstract depiction of a power plant in the background.

Aging equipments can be challenging, especially when they no longer meet operational demands. After years in operation, long-serving excitation equipment is often no longer up to the task. Components of the excitation system may have been discontinued, the frequency of outages becomes unacceptable and grid operators impose new demands on control dynamics. Issues such as shortages of spare parts, excessive outages, and increasing grid requirements can hinder reliable and efficient continuous operation, which is crucial for maintaining the availability of the power plant.

Siemens Energy offers a comprehensive modernization solution for synchronous generators through advanced excitation systems that are compatible with any make or brand. Our turnkey solutions include all necessary components and services, tailored to each power plant’s specific needs, ensuring efficient installation and grid compliance, making reliability non-negotiable in today’s energy landscape.

Excitation systems play a major role in ensuring the reliable continuous operation of synchronous generators. They have a direct impact on generator readiness, dynamic response, and the regulation of reactive power. Modern generator excitation systems are essential for meeting today's demands for performance, flexibility, and grid compliance - especially in power plants where reliablity is non-negotiable.

Our excitation systems are engineered to meet the highest demands of modern power generation - offering maximum grid stability, flexible system integration, and full compliance with international standards. Whether for new installations or retrofit projects, they combine proven technology with advanced digital control to ensure reliable performance, seamless connectivity, and long-term operational security.

Modern excitation system cabinet for generators, essential for reliable voltage control, grid stability, and efficient power plant operation

No matter your footprint, power supply or generator output, Siemens Energy can offer the right excitation system for any application in any power plant.

Static excitation systems (SES) employ the most advanced technology for synchronous generators and synchronous condensers, and are compatible with generators from any manufacturer. SES are suitable for low to high performance classes, from 1 to over 1200 MVA generator output, mainly in hydroelectric, gas, steam and nuclear power plants. These systems are characterized by absolute reliability and maximum efficiency.
Compound excitation systems (CES) are excitation systems for synchronous generators and emergency diesel generators. They are suitable for lower and upper performance classes with a generator power of up to approximately 50 MVA in hydroelectric, gas, steam and nuclear plants (emergency diesel) and are characterized by maximum safety and absolute availability. CES are available as load dependent static and brushless versions.
Automatic voltage regulators for brushless excitation systems (BES) are for generators with (brushless) exciters, and use cutting-edge technology. They are suitable for all performance classes from 1 to over 1000 MVA generator output in gas, hydroelectric and steam power plants and are characterized by absolute reliability and maximum efficiency.

Overview of Siemens Energy excitation systems by field current range, from DIGUREG 2 to THYRIPOL®-6RV80, grouped by system type and machine size

The static excitation system (SES) is a tried-and-tested solution for synchronous machines (generators, motors and synchronous condensers). SES can be used as a stand-alone system or as a compact system in combination with a start-up frequency converter.

Our solution adapts perfectly to the conditions in both newly built or upgraded power plants, regardless of the space conditions, generator type, power supply or control system and regardless of whether the control system is also being replaced at the same time, as well as whether there is a hard-wired or bus connection.

THYRIPOL-S static excitation system front with open cabin

THYRIPOL-S static excitation system front, left side with open cabin

THYRIPOL-S static excitation system front, left side with closed cabin

THYRIPOL-6RV90 static excitation system front with open cabin

THYRIPOL-6RV90 static excitation system backside with open cabin

THYRIPOL-6RV90 static excitation system front, right side with closed cabin

The compound excitation system (CES) is a tried-and-tested solution for synchronous generators of any manufacturer and can be used both as a static excitation system for generators and for excitation of rotating excitation machines. Over 300 installations in operation have demonstrated the unconditional reliability and robustness for years.

Our solution adapts to the conditions in each individual power plant regardless of the available footprint, which generator is used and which power supply and control system is available.

Siemens Energy excitation system in green cabinet, shown in closed state, highlighting modular layout for efficient generator control

Siemens Energy excitation system in green cabinet, shown in open state, highlighting internal components and modular layout for efficient generator control

Open control cabinet with Siemens components, showing a compact and organized excitation system setup for efficient generator operation

DIGUREG-2 for max. continuous current of 34 A

DIGUREG-2 for max. continuous current of 16 A

Siemens Energy DIGUREG 2 voltage regulators alongside a control cabinet featuring integrated regulator technology for precise generator excitation

To guarantee the best solution for each individual case, we first analyze the current situation and the required modifications. We identify which components need replacing, which technology is most suitable, and how the new system can most easily be integrated into the existing plant architecture.

Our primary goal is to achieve unconditional reliability and reduced maintenance costs for our customer's excitation system. For this, we offer excitation systems that fit perfectly into existing plants and processes.

The Siemens Energy turnkey excitation system solution includes all necessary equipment, components and services.

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Illustration of engineer with generator and control system monitoring synchronization and grid stability

Illustration/ key visual for ‘Energy saving solutions' showing a remote service assistant on a desk with a notebook and a headset. Next to her is stands a woman in safety clothing with a clipboard and kneels a man in front of a battery working. The illustration is completed with a reduced, shadowy and abstract depictions of a power plant and two power poles in the back.

Excitation systems for generators - reliable power and grid stability

Reliable operation, stability and fast transient response for synchronous generators and synchronous motors

The right excitation system for every application

Tailored excitation systems for every generator size and application

Our excitation solutions in detail

Your benefits

Siemens Energy offers a turnkey excitation system solution

Downloads

Static Excitation Systems | Flyer

Compound Excitation Systems | Flyer

Brushless Excitation Systems | Flyer

Digital voltage regulator | Flyer

THYRIPOL® 6RV90 | Flyer

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