With the development of power and electronics technology, nonlinear and time-varying electronic devices are used on a large scale, and the requirements of power supply system are getting increasingly higher. The traditional and commonly-used shunt capacitor compensation methods can no longer meet the management requirements of power distribution systems with impulsive loads (e.g. welder, rolling mill, and internal mixer). As one of the core equipment and technqlogies of the flexible AC transmission system (FACTS), the Static Var Generator(SVG) is applied to the var compensation of the power distribution system, which can realize continuous and fast reactive power adjustment from inductive to capacitive, effectively suppress voltage fluctuations and system oscillations, improve load three-phase imbalance, and enhance system stability, which is currently an excellent solution in the field of reactive power control.
product description
The KLD-SVG series Low Voltage Static Var Generator is a kind of high-tech product that breaks through the traditional capacitor and reactor var compensation theory. It integrates power electronics technology, computer technology and modern control technology into one. You can quickly adjust the AC grid var, very effectively regulate the impact var,static var, and even the var in under-voltage conditions, and also have the capability in voltage regulation and harmonic suppression. It is an ideal choice for stabilizing the voltage and improving the power factor. Meanwhile, it has obvious benefits of saving energy,reducing power consumption and increasing capacity of power supply equipment.
The basic principle of Static Var Generator(SVG) is shown in Figure 1.Regarding the system as a voltage source, SVG as a controllable voltage source, the latter uses Insulated Gate Bipolar Transistor (IGBTIGBT) to form a self-phase-change bridge circuit, which is connected in parallel to the grid through reactor, and adjusts its AC-side amplitude and phase of output voltage, or directly control its AC-side current, quickly absorb or emit the required reactive power, and achieve the purpose of rapid dynamic adjustment of reactive power. Figure 2 shows principles of the three SVG operating modes.
Features
Improve power factor, and reduce system losses and fines: SVG has continuous regulation (absorption or output) powerless power, which can stabilize the power factor at 1.0,reduce or even eliminate the line loss caused by reactive power transmission, and can reduce (avoid) the fines caused by reduction of reactive power factor in the power system.
Dynamic adjustment of impulse load, suppression of voltage fluctuation and flicker: SVG has dynamic response speed of less than 10ms, which can eliminate voltage fluctuations and flicker caused by impulsive loads, improve electric power quality, and ensure the normal operation of other electrical equipment on the same bus.
Reduce system installation capacity and lower basic tariff: SVG can achieve full power and continuous compensation. Most of the active power required by transformer to transmit the load will greatly reduce apparent power of the entire substation system, which can reduce the installed capacity of power distribution system, thereby reducing the basic tariff.
Improve the load capacity of distribution transformer: For the power distribution system that has been put into operation, var compensation can be achieved through use of SVG, which can increase the ability of distribution transformer to transmit active power, so that production capacity is improved without increasing the capacity.
Giving consideration to capability of harmonic control: Filtered SVG has both var compensation and harmonic control functions, and is especially suitable for situations where reactive power is the leading factor and small quantity of low-order harmonics are required to be controlled. While ensuring that the power factor reaches the standard, it eliminates system load harmonics in real time, reduces harmonic distortion rate, and improves system safety and reliability.
Advanced: Adopt the latest control theory and quality components;
Flexible: From inductive to capacitive two-way dynamic seamless reactive power regulation,capable of setting the harmonic filtration mode;
High efficiency: Single-phase and three-phase regulation, can achieve power factor increase to approximately1.0;
Rapid: The response speed is fast. Dynamic response time is less than 10ms;
Stable: Suppress voltage fluctuation, flicker and system shock, stabilize system voltage and make system operation more stable;Single-phase dynamic regulation balances the three-phase active power output of the system and suppresses the negative sequence component of power grid.
Energy-saving: The energy-saving effect is obvious, seeing energy consumption reduced by up to 4%~ 15%, and significant economic benefits;
Protection: Capable of system overvoltage, undervoltage protection, and output over current overheat protection, and control integrated prof tion functions;
Convenient: Simple design selection, and easy installation, operation and maintenance.The SVG module can be expanded and operated in parallel;
Safe: SVG is controlled as current source when operating, and will not resonate with the system impedance, which ensures higher safety;
Intelligent operating system with perfect functions : Using new 7-inch LCD smart operating unit, featuring friendly interface and easy operation; The display interface displays the waveform and frequency spectrum of grid voltage, SVG current, load current, and grid-side harmonic currents in real time;Real-time fault record and information query.
Application areas
Industry Automobile manufacturing (welding, stamping), metallurgy (calendering, steel rolling, smelting, crane), ports, petrochemicals, non-ferrous metals (calendering, smelting), electric power, mining, coal chemical industry, military industry, light industry (food processing, tobacco, pharmaceuticals,and sugar making), machinery manufacturing (welding), public facilities (lifting type), machinery, municipal, rail transit, and sewage treatment.
Working Conditions Various reactive power demand occasions, especially for irregular and rapid changes, impact, and three-phase unbalanced load. Calendering (reversible rolling mill, hot rolling and cold rolling), intermediate frequency source (smelting or crystallization), DC heating furnace, electric arc furnace, crane, welder, punching machine, hoist, lifting platform, cable car, internal mixer, stamping machine, rolling mills, forging machines, textile machines, frequency conversion, and Class I loads with rich harmonic content e.g. low voltage rectification and high current.
Technical Parameters
Type selection of KLD LV-SVG
