Static Var Generator (SVG) also known as active power factor compensators (APFC) or instantaneous stepless reactive power compensators are the ultimate answer to power quality problems caused by low power factor and reactive power demand for a wide range of segments and applications.
They are a high performance, compact, flexible, modular and cost-effective type of active power filters (APF) that provide an instantaneous and effective response to power quality problems in low or high voltage electric power systems.
They enable longer equipment lifetime, higher process reliability, improved power system capacity and stability, and reduced energy losses, complying with most demanding power quality standards and grid codes.
Low power factor increases the active energy
losses of installations and affects their stability. It is typically caused by inductive or
capacitive loads that demand extra reactive power to perform properly. Other contributors to
low power factor are harmonic currents produced by nonlinear loads and the change of load in
the electric power system.
SVGs deliver real-time inductive or capacitive reactive power compensation. Rapid
response time provides stable and accurate power factor correction without the drawbacks of
conventional solutions like capacitor banks and reactor banks.
An Static Var Generator is a power
electronics-based device connected in parallel with the load that requires harmonics
mitigation. SVG works as a controlled current source providing any kind of current waveform
in real time.
When the load generates inductive or capacitive current, it makes load
current lagging or leading the voltage. An SVG detects the pase angle difference and injects
in real time leading or lagging current into the electric power systems, making the phase
angle of the current almost the same as that of the voltage, bringing fundamental power
factor to unity.
Main benefits of ALBs can be summarized as:
1. Capability to deliver
instantaneous capacitive and inductive reactive power compensation.
2. Optimized for
highly dynamic applications where conventional capacitor banks or reactor banks are unable
to track the loads.
3. Allow compensation of loads fed by generators without risk of
overcompensation.
4. Inject reactive power that is required by the load at
each instant into the system.
5. Over dimensioning not necessary: Compensation capacity
equals the installed capacity.
6. Unaffected by network voltage drop. Full reactive
current can be provided to meet required demand under reduced network voltage
level.
7. Simple dimensioning and installation.
Typical Applications
SVGs have many low and high voltage potential applications where their use offers many benefits.
⦿ Installations with fast changing reactive power demand
like electric arc furnaces and ball mills.
⦿ Highly
dynamic loads where the power factor fluctuates rapidly or in big steps like cranes, sawmill
machinery, welding machines, etc.
⦿ Correction of
leading power factor like in data centers allowing back-up generators
operation.
⦿ UPC systems.
⦿ Solar inverters and
wind turbine generators.
⦿ Railway electrification systems: Trains &
trams
⦿ Loads with low power factor: Motors,
cables, lightly loaded transformers, lighting, etc.