1.introduction
In the power grid, the use of a large number of nonlinear loads leads to power quality problems become increasingly prominent.Such as electric arc furnace, intermediate frequency furnace, mineral furnace, frequency converter, rectifier and other nonlinear load use, resulting in power quality problems such as flicker, harmonic, imbalance, overvoltage, undervoltage and so on.On the one hand, these power quality problems are difficult to meet the increasing demand for "high", "fine" and "sharp" equipment in production and life, and on the other hand, they also cause the loss of power grid transmission and distribution equipment.Among them, the harm of harmonics is very serious, harmonics reduce the efficiency of the production, transmission and utilization of electric energy, make the electrical equipment overheating, vibration, noise, and make the equipment insulation aging, shorten the service life, and even serious failure or burn, the demand for harmonics control is increasing.
Static Var Generator (SVG) is the most advanced VAR compensation technology in current power system.It no longer uses large-capacity capacitors and inductors to generate the required reactive power, but realizes the qualitative leap of compensation control technology through the high-frequency switching characteristics of fully controlled power electronic device IGBT, especially by improving the control algorithm, the comprehensive compensation of harmonics and reactive power can be realized.
2.FGI scheme
The 35kV power grid of a paper mill is powered by two main power lines into 10kV bus lines in the plant, and the main power line becomes one use and one standby. There are nearly 60 power branches on the 10kV bus, as well as two self-generating units. Among them, the electrical equipment has chlorine dioxide rectification, chlor-alkali rectification, low-voltage frequency conversion and other equipment, mainly with 5 and 7 harmonics, of which 5 harmonics exceed the standard, and the power supply company requires a time limit to control.
In order to control the 5th current harmonics, a 10kV 5Mvar Static Var Generator(SVG) was installed on the 10kV bus, which collected the system voltage, system current and load current, automatically calculated the reactive power demand of the system, quickly and continuously adjusted the capacitive or inductive reactive power output, and guaranteed the stable, efficient and high-quality operation of the power system.
After the operation of Static Var Generator(SVG) equipment, the 5th harmonic current of each power supply is significantly reduced, and the compensation effect is shown in the figure below.
Compensating for pre-voltage harmonics
Compensated after voltage harmonics
3.Product advantage
The FGI Static Var Generator(SVG) device has excellent functional performance and can effectively manage various power quality problems in industrial sites. Compared with traditional compensation methods, it has the following advantages:
Static Var Generator(SVG) can suppress harmonics in the system and deal with the problem of three-phase unbalance.
Static Var Generator(SVG) can be connected to the on-site control system to achieve remote digital control.
Static Var Generator(SVG) can improve the power factor of the site and avoid force adjustment.
Static Var Generator(SVG) models are diverse, there are indoor, outdoor, air cooled, water cooled a variety of models, can be configured according to the site situation the best solution.
The full range of FGISVG solutions
Static Var Generator(SVG) as the most advanced reactive power compensation equipment, thanks to its excellent performance, more and more customers recognize and use Static Var Generator(SVG) to improve power quality and ensure the safety and stability of production work. As a leading brand in the Static Var Generator(SVG) field, FGI continues to carry out technological innovation to provide more professional power quality solutions for users in various industries.
