Questions You Should Know about Static Var Compensators

A Static Var Generator (SVG) is an advanced power quality device designed to provide real-time reactive power compensation and improve power factor. Unlike traditional capacitor banks, SVG offers dynamic, stepless adjustment, ensuring stable voltage and efficient power distribution. It is widely used in industrial facilities, renewable energy systems, data centers, and commercial buildings where power quality and stability are critical. Below are some frequently asked questions to help you understand SVG technology better.

For more information, please visit our website.

Q1: What is a Static Var Generator (SVG)?

A Static Var Generator (SVG) is a power quality device for dynamic reactive power compensation. It helps stabilize voltage levels and improve power factor by injecting or absorbing reactive power as needed. Unlike traditional capacitor banks, SVG provides real-time compensation and works effectively under varying load conditions.

Q2: How do you select a Static Var Generator?

When choosing an SVG, consider the following factors:

-Reactive power demand: Determine the required kVAR rating based on the power system’s reactive power needs.

-Load type: Suitable for industries with fluctuating reactive power demands, such as welding, data centers, and steel plants.

-Response time: Look for fast response times (typically <5ms) for handling dynamic loads.

-System voltage and capacity: Ensure compatibility with the existing electrical infrastructure.

-Installation environment: Consider indoor or outdoor installations and environmental factors like temperature and humidity.

Q3: What is the difference between a Static Var Generator and a Capacitor Bank?

SVG: Uses advanced power electronics (IGBT-based technology) for real-time reactive power compensation, providing continuous, stepless control.

Capacitor Bank: Uses fixed or switched capacitors to compensate for reactive power in discrete steps, which may lead to overcompensation or undercompensation.

Q4: What is the difference between an SVG (Static Var Generator) and an AHF (Active Harmonic Filter)?

SVG is ideal for voltage stability and reactive power control.

AHF is better for harmonic-rich environments and power quality improvement.

For complete power quality solutions, SVG and AHF can be used together in complex electrical systems.

Q5: Is SVG suitable for all types of loads?

SVG is ideal for dynamic loads that require reactive power compensation and power factor correction, including:

Welding equipment (arc welding machines, resistance welding machines)

Elevators, cranes (rapidly changing loads)

Renewable energy systems (wind power, solar PV)

Industrial applications (steel, chemical, cement industries)

Data centers, hospitals, airports (high power quality requirements)
However, SVG has limited effects on pure resistive loads (e.g., electric heaters).

Q6: Will SVG conflict with AHF (Active Harmonic Filter)?

No, SVG and AHF can work together to improve overall power quality:

SVG focuses on reactive power compensation and power factor improvement.

AHF eliminates harmonics and reduces Total Harmonic Distortion (THD).

Using both in combination is ideal for environments with nonlinear loads such as VFDs, UPS, and electric arc furnaces.

Q7: What is the difference between STATCOM and Static Var Generator?

STATCOM (Static Synchronous Compensator) and SVG operate on similar principles, both using IGBT-based technology for fast and precise reactive power compensation.

Key difference: STATCOMs are used in high-voltage transmission systems, while SVGs are more common in low- to medium-voltage industrial and commercial applications.

Q8: How fast is the response time of SVG?

Modern SVGs use IGBT (Insulated Gate Bipolar Transistor) technology, with response times of ≤5ms, much faster than traditional thyristor-switched capacitor (TSC) or Static Var Compensator (SVC) systems, making them suitable for rapidly changing reactive power demands.

Q9: What is the difference between SVG and TSC (Thyristor-Switched Capacitor)?

SVG is recommended for rapidly changing loads, while TSC is better for more stable load conditions. They can also be used together for optimal performance.

Q10: Can SVG be used in renewable energy systems (solar/wind)?

Yes, SVG is widely used in wind power, solar PV, and energy storage systems, providing benefits such as:

Reactive power compensation to improve power factor, ensuring compliance with grid standards (e.g., IEEE-519).

Balancing three-phase currents, reducing grid instability.

Minimizing voltage fluctuations and flicker, particularly in wind and solar systems with variable power output.

Q11: Does SVG help with energy savings?

SVG does not directly save energy, but it can reduce power losses, leading to indirect cost savings by:

Improving power factor, avoiding penalties for reactive power usage.

Reducing line losses, and decreasing the load on transformers, cables, and switchgear.

If you are looking for more details, kindly visit Tongdian.

Stabilizing voltage, enhancing equipment efficiency and lifespan.

Q12: How to determine the required capacity of an SVG?

The required SVG capacity (kVAR) depends on the reactive power demand of the system. General guidelines:

Measure the system’s reactive power requirement (kVAR).

Select an SVG with a rating slightly higher than the peak reactive demand to prevent under-compensation.

In complex load environments, distributed compensation (multiple SVG units) may be more effective.

Q13: Can multiple SVGs be connected in parallel?

Yes, SVGs support modular parallel operation, allowing for flexible expansion as power demands grow. Example applications:

Scaling up capacity by adding more SVG units.

Distributed installation in different electrical branches to optimize compensation efficiency.

Q14: Where should SVG be installed?

SVG should be installed as close to the load as possible to maximize compensation efficiency. Typical installation locations:

At substations or distribution panels (centralized compensation).

Near production areas or load centers (decentralized compensation).

Close to specific equipment (such as VFDs, elevators, welding machines).

Q15: What is the lifespan and maintenance requirement of SVG?

SVGs primarily use electronic components, with an expected lifespan of 15-20 years, significantly longer than traditional capacitor banks.

Maintenance includes periodic cooling system checks, dust cleaning, and monitoring operational status, but overall maintenance is minimal.

Q16: What is the return on investment (ROI) for SVG?

SVGs help reduce power losses, improve power factor, and avoid penalties, leading to an ROI of 1-3 years, depending on:

Electricity tariffs and power factor penalty policies.

Cost savings from reduced reactive power charges.

Lower maintenance and extended equipment lifespan.

Q17: In which industries is SVG most beneficial?

SVG is ideal for industries with dynamic loads, fluctuating power factors, or high reactive power demand, such as:
✅ VFDs, large motors, data centers, steel, chemical plants
✅ Welders, elevators, cranes, port equipment
✅ Solar PV, wind power, energy storage systems

SVG can be used alone or combined with AHF, TSC, or SVC to provide a comprehensive power quality solution.

Tags: dynamic reactive power compensation, power quality device, SVG Static Var Generator, Capacitor Bank.

Related Product:

What is Static VAR Compensator (SVC)? Circuit & Operation in PF Correction

What is Static VAR Compensator – SVC?

A Static VAR Compensator (SVC) also known as Static Reactive Compensator is a device used to improve the power factor of an electrical power system. It is a type of static reactive power compensation device that is used to inject or absorb reactive power into or out of the system to maintain a desired voltage level.

An SVC is a part of FACTS (flexible AC transmission system) and consists of a bank of capacitors and reactors, which are controlled by power electronics such as thyristors or insulated gate bipolar transistors (IGBTs). The power electronics can rapidly switch the capacitors and reactors on and off in order to inject or absorb reactive power as needed. The control system for the SVC monitors the system voltage and current and adjusts the reactive power output of the device accordingly.

SVCs are generally used to compensate for fluctuations in reactive power caused by changes in load demand or changes in generation, such as the output from wind or solar power sources. The SVC works by injecting or absorbing reactive power into the power system in order to maintain a constant voltage and power factor at the point of connection.

Construction of SVC

A Static VAR Compensator (SVC) typically consists of several components, including a thyristor-controlled reactor (TCR), a thyristor-switched capacitor (TSC), filters, a control system, and other auxiliary components as follows.

• Thyristor-Controlled Reactor (TCR): The TCR is a reactor that is connected in parallel with the power transmission line. It is controlled by a thyristor device, which regulates the inductive reactive power.
• Thyristor-Switched Capacitor (TSC): The TSC is a capacitor that is also connected in parallel with the power transmission line. It is controlled by thyristor devices, which regulate the capacitive reactive power.
• Filters and Reactors: used to eliminate the harmonic in the power system
• Control System: The control system of the SVC is responsible for monitoring the voltage and current in the power transmission line and controlling the TCR and TSC to maintain the desired voltage level and power factor. The control system typically includes a microprocessor-based controller, which receives signals from sensors and sends signals to the thyristor devices to adjust the reactive power injection or absorption.
• Auxiliary Components: The SVC may also include other auxiliary components, such as filters, transformers, and protective devices, to ensure proper operation and protection of the system.

Working of Static VAR Compensator

An SVC (Static VAR Compensator) is an electrical device used to regulate the voltage and reactive power (VAR) in electrical power transmission and distribution systems. It is a type of static compensator that uses power electronics to control the voltage and VAR on the electrical grid.

The SVC consists of a thyristor-controlled reactor (TCR) and a thyristor-switched capacitor (TSC). The TCR and TSC are connected in parallel with the power transmission line. The TCR is used to control the inductive reactive power and the TSC is used to control the capacitive reactive power. The combination of the TCR and TSC allows the SVC to quickly and accurately inject or absorb reactive power to maintain a desired voltage level and improve the power factor of the system.

The SVC continuously monitors the voltage and current in the power transmission line and adjusts the reactive power injection or absorption based on the voltage level. If the voltage level drops below the desired level, the SVC will inject reactive power into the system. Conversely, if the voltage level rises above the desired level, the SVC will absorb reactive power from the system.

The TCR and TSC are typically connected in series with a common DC bus, which is controlled by the control system. The control system adjusts the firing angle of the thyristor devices to regulate the reactive power injection or absorption by the TCR and TSC. The combination of the TCR and TSC allows the SVC to quickly and accurately inject or absorb reactive power to maintain a desired voltage level and improve the power factor of the system.

By injecting or absorbing reactive power as needed, the SVC helps to maintain a stable voltage level and improve the power factor of the system. This helps to reduce losses in the system and improve overall system efficiency.

Advantages of VAR Compensator

The Static VAR Compensator has several advantages. An SVR:

• Enhances the power transmission capability of transmission lines
• Improves system transient stability
• Controls steady-state and temporary overvoltage
• reduced line losses and increased system capability
• has no moving parts, hence less maintenance is required
• Improves the overall load power factor

Applications of SVRs

• SVCs are commonly used in high-voltage transmission systems and large industrial plants, where fluctuations in load demand can cause voltage instability and other power quality issues. They can help to improve power system stability, increase power transfer capability, and reduce losses in the electrical grid.
• SVR is used for surge impedance compensation and to compensate for long transmission lines by sectionalizing them.
• Improve the overall power factor for smooth and stable power system.

Related Posts:

Want more information on Static Var Compensators? Feel free to contact us.