When selecting products, many customers often ask me what is SVG and what is the difference between it and SVC? Let me give you some introduction, I hope to be useful for your selection.
For SVC, we can think of it as a dynamic reactive power source. It can provide capacitive reactive power to the power grid according to the needs of access to the power grid, and can also absorb the excess inductive reactive power of the power grid, and the capacitor bank is usually connected to the power grid as a filter bank, which can provide reactive power to the power grid. When the grid does not require much reactive power, this redundant capacitive reactive power can be absorbed by a paralleling reactor. The reactor current is controlled by a thyristor valve set. By adjusting the thyristor trigger phase Angle, we can change the effective value of the current flowing through the reactor, so as to ensure that the reactive power of SVC at the access point of the grid can just stabilize the voltage of the point within the specified range, and play the role of reactive power compensation of the grid.
SVG is a typical power electronic equipment, which is composed of three basic functional modules: detection module, control operation module and compensation output module. Its working principle is to detect the current information of the external CT system, and then analyze the current information, such as PF, S, Q, etc., through the control chip; Then the controller gives the compensated drive signal, and finally the inverter circuit composed of the power electronic inverter circuit sends out the compensated current.
The SVG static var generator consists of a self-commutating bridge circuit composed of a turn-off power electronic device (IGBT), which is connected to the power grid in parallel through the reactor, and the amplitude and phase of the output voltage on the AC side of the bridge circuit can be properly adjusted, or the current on the AC side can be directly controlled. Quickly absorb or emit the required reactive power to achieve the purpose of rapid dynamic adjustment of reactive power. As an active compensation device, it can not only track the impulse current of impulse load, but also track and compensate the harmonic current.
SVG and SVC work differently. SVG is a reactive power compensation device based on electronic devices. It adjusts reactive power by controlling the on and off of power electronic devices. SVC is a reactive power compensation device based on reactance device, which adjusts the reactive power by controlling the reactance value of the variable reactor. As a result, SVG has faster response and higher accuracy, while SVC has greater capacity and more stable performance.
SVG and SVC are controlled differently. Static var generator uses the current control mode, that is, according to the phase and amplitude of the current to control the power electronics on and off. This control mode can achieve accurate adjustment of reactive power, but it requires high response speed of current. And SVC adopts voltage control mode, that is, according to the phase and amplitude of the voltage to control the reactance value of the variable reactor. This control mode can realize the stable adjustment of reactive power, but it requires high voltage response speed.
The scope of use of SVG and SVC is also different. SVG is suitable for applications that require high voltage fluctuations, such as power plants, substations and large industrial enterprises. It can improve voltage stability and power quality of power system through fast response and precise control. SVC is suitable for applications that require high current fluctuations, such as electric arc furnaces, rail transit and mines. It can improve the power factor and stability of power system by
adjusting the current stably.
Post time: Mar-15-2024