Brochure · EN — 4-page Siemens Energy Grid Technologies brochure (DIN A4, 2025) on the E-STATCOM for data center applications: a STATCOM additionally equipped with super-capacitors and a dedicated control system that actively mitigates the load fluctuations of AI data centers directly at the load. It explains the working principle (parallel connection at or behind the point of coupling, compensating active power load swings while providing or absorbing reactive power), lists the per-unit rating (115 MVA installed power, +/- 75 MVAr reactive power, +/- 75 MW active power cycle, connection at any voltage from 34.5 kV to 750 kV), describes the SVC PLUS FS-based scope (Modular Multilevel Converter in B6-topology with a supercapacitor energy storage on the DC terminals), the standardized layout (a 75 MW unit has a footprint of approx. 300 x 100 ft / 90 x 30 m), the NERC CIP-compliant control and communication topology, availability per CIGRE TB 717, testing, manufacturing in Nuremberg, Germany, and the installed base of the underlying MMC technology (more than 150 systems, more than 15 years of operational experience).
Data centers represent significant electrical loads, often reaching gigawatt levels. In addition AI data centers produce load fluctuations. The fluctuations are in the subsynchronous frequency range down to very low frequencies matching with interarea power oscillations or sub synchronous oscillations, a widely known phenomena in the operation of electrical systems. This can cause instabilities in the transmission grid or in islanded grids.
The E-STATCOM for data center applications is a STATCOM additionally equipped with super-capacitors and a dedicated control system, which actively mitigates the load fluctuations directly at the load. This reduces the load fluctuations by smoothing the active power load pattern at the point of connection. It maintains the power quality of the electrical system within the permissible range. The E-STATCOM for data center applications is based on proven PLUS technology by Siemens Energy, relied on by hundreds of utilities.
The E-STATCOM is connected at or behind the point of coupling of the AI data center in parallel to the load and compensates for the active power load swings. At the same time, the E-STATCOM can provide or absorb reactive power from the grid or the load. This stabilizes the electrical system's voltage. A schematic on page 1 shows the E-STATCOM and the fluctuating AI data center load connected in parallel toward the grid.
Data centers for AI-computing show high fluctuating active power cycles. The E-STATCOM compensates the alternating load cycles by injecting out of, or absorbing active power into, its short-term storage unit. A two-panel time-series diagram on page 2 (legend: load compensation, grid without E-STATCOM, grid with E-STATCOM; time axis 20-180 seconds) shows the resulting red active power demand from the grid if E-STATCOM is in operation, the blue line shows the active power demand without E-STATCOM, and the purple line shows the load compensation.
The E-STATCOM for data center applications provides typical STATCOM features on top of the active power damping. The main features are: active power compensation, reactive power compensation, voltage control, flicker compensation, peak load shaving, and enhancing the load fault ride-through capability.
One unit has the following rating (table transcribed verbatim from page 2). The modular design of the system allows for easy expandability, enabling multiple units to be installed in parallel and coordinated effectively.
| Parameter | Value |
|---|---|
| Installed power Snom | 115 MVA |
| Reactive power Qnom | +/- 75 MVAr |
| Active power cycle | +/- 75 MW |
| Connection voltage | Any voltage from 34.5 kV to 750 kV |
The Siemens Energy solution for an E-STATCOM is referred to as SVC PLUS FS®, represented schematically in a single-line diagram on page 3. The E-STATCOM for data centers is equipped with a Modular Multilevel Converter (MMC), connected in B6-topology, which provides the reactive and active power control. The DC terminals of the MMC are connected to an energy storage unit, consisting of bulk numbers of supercapacitors. The modular approach in design provides the possibility of adding parallel branches to achieve higher power ratings.
Supercapacitors were identified as the optimal choice of storage element due to their high power density, low internal resistance and long service life independent from the number of load cycles. During active power load compensation, supercapacitors are capable of providing or absorbing high levels of active power in the shortest response time aligning perfectly with the requirements of highly dynamic variable load compensation.
Main components (numbered in the single-line diagram): 1 super capacitor storage, 2 multilevel converter, 3 phase shifting reactors, 4 MV switchyard, 5 power transformer, 6 HV switchyard. Further scope: control and protection system, cooling system, auxiliary supply, electrical and mechanical building supply, civil installation. Services: engineering, procurement, delivery, installation, commissioning. Scope split between customer and Siemens Energy can be discussed — from full turnkey solution to equipment supply only. On request, a containerized solution is possible.
The E-STATCOM for data center applications features standardized components in a standard layout that can be adjusted to site conditions. A 75 MW unit has a footprint of approx. 300 x 100 ft (90 x 30 m).
A communication-topology diagram on page 3 shows the operator level (operator interface HMI; communication interface, firewall), station communication with data aggregation, fault recording and time synchronization, the control level (main control system, protection, HVA/C control, converter water cooling control, fast processing control / converter controls, super-cap monitoring, measuring and yard interfaces) and the field level (HVA/C system, converter water cooling system, power electronics interface, super-cap unit, high-voltage equipment).
The control system topology is a fully integrated and automated control system. The system can be operated completely remotely via the Scada interface (e.g. DNP 3.0 or IEC61850). A service interface for remote access is integrated. The system is NERC CIP cyber security compliant.
The E-STATCOM for data center applications complies with availability standards per CIGRE TB 717 for bulk electrical systems. Redundancy is built in within the system, so optimum availability can be guaranteed.
All systems are type-tested based on the type design for the E-STATCOM for utility applications. Factory testing is done during project execution. All components are tested on insulation, operational currents and short circuits. The control system is comprehensively tested through EMT-simulations with embedded original control codes and with a real time simulator (RTDS) as hardware in the loop test. Factory routine tests are performed for all systems to guarantee premium quality and customer satisfaction.
The modular multilevel converter is based on the Siemens Energy PLUS technology, which is manufactured in the Siemens Energy converter factory in Nuremberg, Germany, and is used worldwide in HVDC and STATCOM applications. The supercapacitor energy storage is manufactured and tested in Germany. The control system is manufactured and tested by Siemens Energy.
The system consists of outdoor and indoor equipment. The indoor equipment will be installed in a predesigned building, which can be constructed by a construction company for substations or other industrial facilities.
The installation of the system is standardized and can be performed by companies experienced in substation works. Siemens Energy uses a wide range of subcontracted suppliers. Installation supervisors will be from Siemens Energy. The commissioning is performed by experienced Siemens Energy experts.
The E-STATCOM for AI data center applications is based on the E-STATCOM system for utility applications. In Germany one installation will go into service in 2025. Siemens Energy was the first who introduced the modular multilevel converter technology and has an installed base of more than 150 systems of this kind with more than 15 years of operational experience.
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