Electrical Solutions

SPPA-T3000 PD Connectivity

Electrical solutions for electrical systems tailored to power plants

SPPA-E3000 is our integrated solution for all electrical systems in power plants. SPPA-E3000 Electrical Solutions are not just for any factory. They are tailored to the critical, behind the scenes infrastructure of power plants. Our electrical solutions are suitable for all types and makes of power plants. They work with turbines and generators from any manufacturer as well as any OEM system.


Our Solutions

Whether you are planning a new plant or looking for a partner for comprehensive modernization, SPPA-E3000 Electrical Solutions for power plants not only cover the electrical systems but also the complete project management: Our team manages the entire process – from basic engineering to commissioning. We optimize designs, handle all interfaces and make sure all electrical systems work together properly. Learn more about our comprehensive electrical solution specially tailored to the electrical systems needed in power plants.

SPPA-E3000 Electrical Solutions cover a large variety of topics concerning your plants electrical infrastructure. 


We have tailored specific packages correct for all common tasks:

SPPA-E3000 Unit Protection & Synchronization

Modernizing power system protection as well as the synchronization system

The major electrical systems are crucial to the availability of power plants. Therefore, power system protection should prevent potential causes of major damages such as shutdowns and incorrect synchronization of generator and grid. Unfortunately many installed systems are no longer adequately able to cope with protection tasks and their maintenance is becoming increasingly difficult.

Our solution SPPA-E3000 Unit Protection & Synchronization allows for replacement of the unit and power system protection, as well as the synchronization system. The package uses modern grid protection philosophies that satisfy the most sophisticated requirements in terms of response precision. SPPA-E3000 Unit Protection & Synchronization therefore naturally complies with the latest grid requirements. This is based on special hardware, redundant configuration, and instrumentation that incorporate diverse-mode measurements.

The benefits of our optimized power system protection:

  • Maximum plant safety and availability thanks to precise response
  • Higher availability due to faster control room staff response
  • Protection of assets invested in the power plant 

SPPA-E3000 Unit Protection & Synchronization: High quality devices and comprehensive services

SPPA-E3000 Unit Protection and Synchronization replaces outdated components with sophisticated reliable protection technology incorporating SIPROTEC devices. The multifunction relays are a high-quality, digital technology that set the benchmark for modern protection systems.


Before replacing the existing relays, we review the protection philosophy in place. This includes computational analysis of protection needs, and when necessary, the discussion of a new solution. Our design and configuration of reliable protection technology is always tailored specifically to your power plant.


The solution includes:

  • Reliable protection technology, current and voltage transformers
  • Communication with existing instrumentation and control systems
  • Time-optimized installation/commissioning
  • Complete documentation
  • Review of existing protection concept and development of a new concept when necessary
  • Computational analysis of protection needs
  • Synchronization system
  • Unit transformer protection
  • Generator protection
  • Auxiliary transformer protection
  • Integration in the plant DCS with SPPA-T3000 in accordance with IEC 61850 

Synchronous Condenser Conversion

A synchronous condenser is a generator without a prime mover from a gas or steam turbine. It stabilizes the grid in changing reactive power demands. The rotating mass and the dynamic generation of reactive power stands for the high advantages of this product. Short circuit power supply and the frequency stabilization are the main benefits of the synchronous condenser.

Any existing power plant generator type could be converted into a synchronous condenser. It could supply the grid with short circuit power and could ensure permanent dynamic voltage and reactive power control. Synchronous condenser aim to stabilize the frequency and support the voltage also for long distances. They could generate electricity during dynamic peak demands and have the capability to build up the grid after black-out. The project time for converting the plant is usually less than 12 months. The solution allows to utilize existing assets and therefore offers a very short Return on Investment (ROI).


Benefits include:


  • Minimum costs due to re-use of the existing generator and relevant auxiliary systems. Written-off assets can be reactivated.
  • Extended lifetime of a power plant generates additional revenue.
  • Decreased danger for blackouts as grid is in an optimum range of operation due to improved cos y and increase of short capability.

SPPA-E3000 Drive Modernization

Optimizing the energy consumption of drive systems

Over two thirds of the plant's auxiliary power demand comes from electrical drive systems. More than 97% of the entire life-cycle costs result from their energy consumption. About 30% of drive systems for say pumps and fans could be run more efficiently. This considerable savings potential is just waiting to be tapped. With SPPA-E3000 Drive Modernization the energy efficiency of drive systems can be significantly optimized

The benefits of our SPPA-E3000 Drive Modernization package:

  • Less energy costs of auxiliary power
  • Reduced environmental burden
  • Higher returns thanks to higher capacity and lower CO2 emissions
  • Short payback period

SPPA-E3000 Drive Modernization: Significantly cutting energy costs

Electrical energy savings can be achieved by installing frequency converters, as these operate motors optimally at their load point.

A second option is to implement electronic speed control. Replacing existing motors with modern, more efficient drives also significantly improves their efficiency.


SPPA-E3000 Drive Modernization includes assessment of potential savings, analyzing analysis of suitable measures, and implemention of them to modernize the drive systems. The focus is first set on drives that promise a short-term return on investment for the cost of the upgrade.

 The scope of supply at a glance:

  • Electronic speed control instead of mechanical throttling
  • Modernization of installed frequency converter
  • Use of energy-saving motors
  • Recovery of decelerating energy during breaking

SPPA-E3000 Excitation Systems & Start-up Frequency Converters

Innovative excitation systems for maximum reliability

The excitation system plays a major role in ensuring the reliable continuous operation of synchronous generators, since it significantly influences the operational readiness and dynamics of the generator. Moreover, it controls the reactive power response of the synchronous machine. Innovative excitation systems, especially designed for power plants thus are at center stage when maximum reliability must be achieved.

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.

Siemens Energy has put its many years of experience as a power plant developer, constructor and operator into developing innovative excitation equipment.

SPPA-E3000 Excitation Systems have been specifically developed for secure continuous operation in power plants. They can be used with synchronous generators from any manufacturer and cover all ratings of industrial, hydroelectric, steam and nuclear power plants.

No matter what the requirements, whether footprint, power supply or generator output, Siemens Energy can offer the right excitation system for any application in any power plant based on its range covering.

  • SES: static excitation systems
  • SFC/SES: start-up frequency converter with static excitation system combined in a compact unit
  • CES: compound excitation systems (= load-dependent excitation systems)
  • BES: brushless excitation systems (= rotating excitation systems)

Learn more about SPPA-E3000 Excitation Systems & Start-up Frequency Converters:

SPPA-E3000 Excitation Systems & Start-up Frequency Converters

SPPA-E3000 Excitation Systems & Start-up Frequency Converters offer a return on investment after only a short time. The modular design of the excitation systems as well as the use of proven industrial components contribute significantly to reliability and to the reduction of maintenance costs.


The modernization of excitation systems demands a broad range of skills to handle site survey, design, and commissioning. Our overall project management ensures minimum processing and outage times.

Smooth project execution turns our excitation systems into solutions:

  • All necessary components and services are included in the turnkey excitation system solution
  • To guarantee the best possible 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 target is to realize unconditional reliability and reduced maintenance costs for our customers’ excitation system.

To achieve this, we offer excitation systems that perfectly fit to existing plants and processes.


Benefits of our excitation systems solutions:

  • Maximum reliability thanks to robust design suitable for power plants
  • Low maintenance costs due to use of proven industrial components
  • Minimum time for replacement of the existing excitation system, with no changes to the I&C or to the exciter

SPPA-E3000 Excitation Systems & Start-up Frequency Converters

Our range of excitation systems can be used with synchronous generators from any make or brand. 
Thanks to their technology, they can be used with generators of all sizes in hydro, steam, nuclear and industrial power plants and together with gas turbine units.

With the SES static excitation systems, and compact units consisting of excitation systems and start-up frequency converters, CES load-dependent excitation systems, and BES brushless excitation systems, Siemens Energy offers the right excitation equipment for any application in any power plant -  Regardless of requirements, whether footprint, power supply, or generator output. 


  • SES – static excitation systems
  • SFC/SES – start-up frequency converters with static excitation systems
  • CES – compound excitation systems
  • BES – brushless excitation systems

Reliable excitation systems that always fit the bill

SPPA-E3000 Static Excitation Systems (SES) are static excitation systems for synchronous generators and synchronous condensers. They are used in gas turbine, combined-cycle, hydroelectric, nuclear, steam and industrial power plants with medium to high ratings. They can be used as stand-alone systems or as compact systems in combination with a > startup frequency converter.


Highly flexible solution to boost efficiency and dynamics 
Siemens Energy provides a customer-oriented redundancy concept and its highly flexible technology offers individually tailored modernization solutions. The static excitation systems can be adapted to the conditions in any power plant, regardless of the layout of the available installation area or the type of generator, power supply or I&C, with an analog or bus connection, regardless whether the I&C is also replaced or left as-is.

Replacement of your existing excitation system with the SPPA-E3000 Static Excitation Systems SES will offer increased plant efficiency, outstanding dynamic behavior, processor self-monitoring, local visualization and remote diagnostic capabilities.


Benefits from our static excitation systems
■ Maximum reliability thanks to robust design customized to fit individual plant conditions
■ High efficiency and dynamic control response thanks to cutting-edge technology
■ Low maintenance costs thanks to the use of proven industrial components
■ Simple replacement of existing excitation system in the shortest time possible, with no interface problems

Compact unit for gas turbines to achieve maximum availability and flexibility

The start-up frequency converter serves as a starting aid for gas turbines of any size. The power output of the start-up frequency converter ranges from 1.4MW to 9.0MW or – if required – even higher. In combination, a static excitation system (SES) and the start-up frequency converter make up a compact unit. Due to its compact design, the solution is especially suited for plants with space restrictions, e.g. in a container.


SPPA-E3000 Start-up Frequency Converters with Static Excitation System (SFC/SES) are designed as compact units with a common control unit cabinet. The major advantage of choosing a compact unit is surely the perfect match of its two included components. 

Comprehensive plant-specific redundancy concepts, like cross-start, ensure maximum availability and flexibility of the entire power plant. Built-in latest digital technology and support in spare parts of at least 10 years are important characteristics of the Siemens Energy offering. The SPPA-E3000 Start-up Frequency Converters with Static Excitation Systems have been designed as a standard series and naturally they fit gas turbines of any types and makes.


The approach to flexible integration and boosted availability of SFC/SES systems:

In many cases, after 10 to 20 years in operation, the present static excitation system and start-up frequency converter in a plant have to be replaced. This may be due to obsolescence of the whole system or major components, or obsolescence of repairs, services and spare parts. Other reasons may be an increase of generator output or changing market conditions, like requirements from a new grid code. In the case of a failure of the compact unit, the plant operator would not be able to run the gas turbine anymore – a critical risk for the availability of the entire power plant.

To eliminate this risk, our experts analyze the initial situation in the individual plant. The project teams thoroughly check the different components to find out if the whole aging technology needs to be upgraded of if it is possible to keep e.g. the existing power section. In both cases – complete SFC/SES compact unit replacement or AVR replacement only - optimized project execution ensures that minimal conversion times are realized.


Benefits from our start-up frequency converters with static excitation system:

■ Reduced obsolescence risk by replacement of aging systems and components
■ Utmost availability thanks to spare parts availability and ongoing service support
■ Minimized outage time through optimized project execution 
■ Perfect fit into existing plant environment thanks to compact design

Load-dependent excitation systems with uncompromising availability and maximum reliability

SPPA-E3000 Compound Excitation Systems (CES) are load-dependent excitation systems (also called compound excitation systems) for synchronous generators and emergency diesel generators with or without exciters. Its high flexibility and modular design make it suitable for use in hydroelectric, steam and nuclear power plants, and especially for the modernization of existing units.

Their functional design ("Harz circuit" with oscillating circuit and use of strictly passive components for basic excitation) makes SPPA-E3000 Compound Excitation Systems especially suitable for emergency diesel generators in nuclear power plants and ensures maximum reliability and availability.

Black start capability and short-circuit support for high reliability and availability

The excitation current supplied by SPPA-E3000 Compound Excitation Systems consists of a voltage dependent (no-load dependent) and a current dependent (load dependent) part. The system supplies the energy required to excite the generator directly via slip rings. 

The compound excitation system’s no-load component of the compound excitation systems is supplied by the excitation transformer and converted into current in a Harz circuit. The load component is supplied by the excitation transformer and converted into current in a Harz circuit. The load component of excitation is supplied by the excitation current transformer.

The current-dependent component of excitation also serves to boost or maintain excitation in the event of voltage dips or short circuits.


The oscillating circuit is supplied by the voltage generated from residual magnetism during startup, thus enabling the generator to operate as a self-excited machine without an external power source.


Benefits of our compound excitation systems: 
■ Uncompromisingly high reliability and availability of excitation system – thanks to a unique reliability concept
■ Simple replacement of existing excitation system in the shortest possible time, with no interface problems
 Low maintenance costs through the use of proven components and modular design

Reliability for every kind of power plant at minimum change-out time

SPPA-E3000 Brushless Excitation Systems (BES) are brushless excitation systems (= rotating excitation systems) for synchronous generators with exciters. Due to their high flexibility combined with modular hardware and software design, they are suitable for use in any type of power plant.


Comprehensive redundancy concepts ensure maximum availability. Thanks to ergonomic and transparent depiction of operating conditions, and the excellent interaction of the generator protection and the I&C, switching to SPPA-E3000 Brushless Excitation Systems (BES) improves operability.


SPPA-E3000 Brushless Excitation Systems perfectly fit any generator size, from 1 to over 1000 MVA, and any system configuration - independent of country or requirements of the grid operator.


Smooth replacement of the existing brushless excitation system

Electrical components like a brushless excitation system – a system in which the exciter rotates on the rotor shaft – will sooner or later reach the end of their service life. Thanks to the simple plug-out/ plug-in replacement method, switching from the installed brushless excitation system is no problem, and minimum change-out times are realized.


Of course Siemens Energy will ensure smooth replacement from planning trough commissioning, and will then continue to support your new SPPA-E3000 Brushless Excitation System (BES) in service. Independent from the type or model of generator or exciter, power supply or control system, or whether the I&C is also replaced or left as-is: SPPA-E3000 Brushless Excitation Systems (BES) can be adapted to the conditions in your plant.

Your benefit from the high flexibility of our rotating excitation systems:
■ Minimum outage time with „unplug/ plug in“ replacement of the installed excitation system
Reliable continuous operation with proven rotating excitation systems
SPPA-E3000 Brushless Excitation Systems (BES) are proven solutions for all synchronous generators and reactive power generators. Several thousand systems in operation throughout the world have been demonstrating the absolute reliability and robustness of these systems for many years.


Your benefit from the robust, proven technology of our brushless excitation systems:
■ Maximum reliability and availability
 Low maintenance costs with use of proven industrial components and modular design
 Extremely simple and thus error-free operation thanks to transparent depiction of operating condition

Training Electricals

Training opportunities to meet your needs

At Siemens Energy we provide you with a training experience on our Electrical Solutions that is applicable to your daily challenges and needs. In Siemens Energy, we have a global training network with highly experienced and qualified instructors that can provide a wide range of training options (in-person, web-based and virtual) with cutting edge technology, designed specifically for various plant personnel positions. Many of our courses can be customized to meet your schedule and budget requirements.