In modern power systems, industries with an increasing demand for high quality power are faced with the problem of providing ultra-stable, efficient power. Static reactive generators (SVG) provide a dynamic, real-time solution to these power quality problems.

Different from traditional compensators, SVGs operate in parallel with electrical loads to stabilize grid voltage, eliminate harmonics, and optimize power factor with millisecond response times for applications ranging from renewable energy integration to heavy industrial facilities.

What is a Static Var Generator (SVG)？

Static reactive power compensator (SVG), also known as static synchronous compensator (STATCOM), is an advanced power electronic device designed for dynamic reactive power compensation and harmonic filtering in power grids. It is capable of quickly adjusting the current phase to compensate the reactive power of the system within milliseconds by monitoring the current and voltage in the grid in real time.

Understanding Phase Differences

Purely Resistive Loads‌: For example, electric light bulbs where current and voltage remain in phase (0° phase difference). Here, 100% of the power is active power (P).

Inductive Loads‌: Such as motors and transformers where the current lags voltage by 30°–90° (typically 85° for industrial motors). This generates reactive power (Q) that sustains electromagnetic fields without performing useful work.

Capacitive Loads‌: Like capacitor banks where the current leads voltage by 30°–90°. This produces reactive power (Q) that oscillates between the source and load, crucial for power factor correction.

Reactive power plays a role in establishing and maintaining electric and magnetic fields in power systems. For example, an induction motor requires reactive power to establish a rotating magnetic field for proper operation.

How SVGs Improve Power Factor?

Dynamic Compensation‌:

SVGs sense grid demands in real time (<20ms), intelligently injecting/absorbing reactive current (e.g., 90kvar support for motor startups) to balance inductive/capacitive loads.

Harmonic Neutralization‌:

Integrated FFT algorithms eliminate 3rd–50th harmonics (THD reduced from 15% to <5%), preventing harmonic-induced losses and IEC 61000-4-7 compliance risks.

Adaptive Regulation‌:

IGBT-based switching (5kHz) enables smooth reactive adjustments vs. capacitors' 300ms stepped response, critical for welding machines/rolling mills with ±100% load spikes.

Application Scenarios

SVGs are widely used in various power environments in the following scenarios:

Industrial production systems:

Heavy motor starting: When starting large induction motors such as compressors, pumps, fans, etc., SVGs can provide the instantaneous reactive power needed to prevent transient voltage drops.

Arc furnaces, welding machines, etc.: These non-linear loads introduce harmonics and fluctuations in reactive power, and SVGs can be used to correct the power factor and eliminate harmonics to ensure power quality.

Renewable energy systems:

Wind power: Especially in asynchronous generator-type wind power systems, SVGs absorb reactive power to maintain grid stability and ensure proper voltage levels.

Solar photovoltaic systems: In photovoltaic power stations, SVGs can be used to balance voltage fluctuations caused by changes in lighting and improve the quality of the power output.

Distribution Networks:

In urban distribution systems and industrial parks, SVGs can improve overall power factor, reduce power losses and avoid penalties due to low power factor.

Power transmission systems: In long-distance transmission, SVGs can cope with voltage fluctuations on transmission lines and help improve voltage stability.

Transport and Infrastructure:

Electric Vehicle Charging Piles: SVG can optimise the power factor during charging to ensure efficient and stable operation of charging piles.

Highway and railway power supply: SVGs are widely used in transport facilities to ensure the stability of power supply and improve energy efficiency.

Onesto SVG Product Features

Stepless compensation: SVGs provide continuous compensation with the ability to flexibly adjust the power factor in the range of 0 to 1, which is more flexible than the fixed level compensation of traditional equipment.

Multiple compensation modes: Support multiple compensation modes (such as reactive power, harmonic, balance, etc.) to meet the needs of different types of loads and adapt to a variety of complex power environments.

Harmonic Suppression: SVG not only provides reactive power compensation, but also actively eliminates harmonics in the power system, reducing the negative effects that may be caused to electrical equipment.

Efficient use of energy: Increased power factor (PF > 0.98) reduces power losses and thus improves the overall energy efficiency of the grid.

Fast Response Capability: SVG can complete reactive power compensation within 5 milliseconds, which significantly improves the response speed to load changes, thus enhancing the stability and reliability of the power system.

Efficient Protection and Durability: The product is potted with high thermal conductivity glue, which not only protects against environmental factors, but also improves heat dissipation. Designed with a variety of extreme conditions in mind, such as high temperature, high humidity, dust, etc., the adaptability to these environments is stronger than many peer products, which makes our equipment more reliable.

High Power Density: Onesto SVGs use a unique copper foil vertical winding process that allows for a smaller unit with higher power. Many of our competitors have more traditional designs that are larger and less efficient.

Modular design: SVG supports modular configuration, users can flexibly add or subtract modules according to their needs, and up to 20 modules can be run in parallel to meet the needs of systems of different sizes.

Application Programme:

1. High extraction and low compensation(CT access to SVG)

2. High extraction and low compensation (Multi-function meter access RS485-SVG)

3. High extraction and low compensation (Multi-function meter access Lora-SVG)