Frequency and voltage support for dynamic grid stability

SVC PLUS (STATCOM) Frequency Stabilizer®

As the infeed of power from renewable sources continues to replace conventional synchronous power generation, the grid frequency is becoming more sensitive due to the reduced amount of rotating machines. Now grid operators are faced with the challenge of providing sufficient system inertia in their synchronous generators with high rotating masses to stabilize the grid. Because renewables have little to no inertia, and can’t be used for frequency stabilization, other solutions are needed.

A convincing solution

By using a bulk number of supercapacitors, the new SVC PLUS Frequency Stabilizer® (SVC PLUS FS®) is a cost-efficient, compact solution that can emulate system inertia by boosting high active power into the grid when needed. It also offers voltage support by means of reactive power compensation.

While grids are undergoing fundamental changes in terms of power generation, renewable infeed and ever-growing demand, power quality and dynamic grid stability are at risk due to less synchronous power generation.

The grid frequency is balanced to 50 Hz or 60 Hz by parity of power demand and generation. The frequency must be kept within specific limits, even in the event of an imbalance: for example, from a disturbance. After a fault, the frequency can only be stabilized by an inertial response from generator-turbine sets. The mechanical kinetic energy defines the frequency drop after disturbance until the operating reserve is activated after several seconds by the primary frequency reserve (PFR). Fewer rotating machines result in shrinking instantaneous reserves, which increases the risk of exceeding critical frequency levels. This may lead to load rejection or a blackout. Grid operators are forced to keep power plants in operation in order to preserve the instantaneous reserve or to optionally invest in additional primary reserve. Some source of fast frequency response (FFR) is urgently needed to cover the gap between inertial response and operating reserves.

Blackout prevention

Combining SVC PLUS® (Modular multilevel STATCOM) and supercapacitors that allow +/–50 MW of active power output/input for up to several seconds, SVC PLUS FS® is an ideal tool for fast frequency response in the first few seconds of a major grid disturbance. While the STATCOM part provides inductive or capacitive reactive power of +/-70Mvar with a the step response of less than 50ms, the electrical energy in the super-capacitors is boosted into the grid in order to secure the grid from load shedding or blackout.


Cost-effective solution

The supercapacitors are the economical solution of choice to provide high power density at a space-saving footprint. Due to low losses and easy maintenance low lifetime expenditures can be achieved.


Short response time

The SVC PLUS FS® is geared up for quick injection of reactive and active power and is therefore a highly dynamic solution for voltage regulation and frequency stabilization.


Better control of power grids, faster adaptation to load changes

Putting grid stability and power quality into practice, SVC PLUS FS® offers a number of typical applications:

With a fast active power injection, the SVC PLUS FS® covers the time gap between a grid disturbance and the activation of operating reserves.

The SVC PLUS FS® combines dynamic voltage (STATCOM operation) and frequency support in one unit.

The SVC PLUS FS® provides various system services that reduce the need of must-run capacity, which is currently provided by conventional power plants.

Disturbances at interconnections can lead to a cascading event in weak grids. To counter this, the SVC PLUS FS® solution can flexibly and quickly change between injection and absorption of active power, thus strengthening the link by reducing overfrequency and frequency drops.

The SVC PLUS FS® supports renewable power generation by providing grid code compliance.

SVC PLUS FS®: more options for grid operators

In challenging times like ours, grid operators need versatile resources that give them options not only to react, but to act proactively, as depicted in the usecases/applications above. At that, with SVC PLUS FS®, operators can be sure of a reliable, economical and space-saving solution with many advantages in terms of response time, control accuracy, and economic impact.

Have a closer look at the SVC PLUS FS®: 3D Experience

Key technical parameters of SVC PLUS FS®

  • Can address any voltage level
  • Footprint: 2,700 m2
  • Active power: Pmax = +/–50 MW
  • Reactive power: Q = +/–70 Mvar
  • Available energy: 450 MJ
    (upscaling to 4x units in parallel possible)

Additional information

PDF (2 MB)

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Optimal grid and frequency stability

With SVC PLUS FS® , Siemens Energy further enhanced the capabilities of a static synchronous compensator (STATCOM) with modular multilevel converter (MMC) technology to also support fast frequency response. Whenever your applications require a highly dynamic solution for voltage regulation and fast frequency support, the SVC PLUS FS®  is the first choice.