Publish Time: 2022-03-16 Origin: Site
STATCOM is a facts device with parallel reactive power compensation. It can emit or absorb reactive power, and its output can be changed to control specific parameters in power system. Compared with traditional reactive power compensation devices, STATCOM has the advantages of continuous regulation, small harmonic, low loss, wide operation range, high reliability and fast regulation speed. Since its inception, STATCOM has received extensive attention and rapid development. This article will briefly introduce the STATCOM and state the importance of the STATCOM.
The following is a list of contents
Basic concept of STATCOM
Importance of STATCOM
STATCOM, also known as SVG, is a dynamic reactive power compensation equipment based on voltage source converter. It is a typical representative of the second generation facts device. A reactive power dynamic compensation device for generating and absorbing reactive power by a self commutating power semiconductor bridge converter. It is composed of AC link and DC link. The AC link is connected with the system. It first converts the AC energy of the system into DC through the converter and stores it in the energy accumulator on the DC side. At the same time, the voltage and current on the DC side are transformed into AC voltage and current through the converter and transmitted to the system.
It regards the converter circuit as an AC voltage source that generates fundamental and harmonic voltages. By controlling the magnitude and phase of the fundamental voltage of the compensator, the magnitude and phase of the fundamental reactive current can be changed. When the fundamental voltage of the converter is higher than the AC power supply voltage, the converter will produce a leading (capacitive) reactive current. Conversely, when the fundamental voltage of the converter is lower than the AC power supply voltage, a lagging (inductive) reactive current will be generated. Therefore, it can exchange reactive power with the system and is "static" at the same time, so it is also called Static var generator (SVG). Different from the capacitor that current also decreases in proportion at low voltage, the static reactive power generator can produce rated current under various system voltages, which is similar to the rotating synchronous motor with three sinusoidal symmetrical voltage.
STATCOM is widely used in high-voltage transmission systems, generally for midpoint compensation. After adding STATCOM into the line, the current and voltage injected into the system will change the parameters of transient and steady-state operation, thus affecting the existing protection performance.
Because STATCOM can quickly adjust the parameters of power system, STATCOM injects new energy into the line, resulting in rapid changes in system parameters and structure. Relay protection is the basic basis for judging the operation state of power system, and it is also the main parameters of power system, such as voltage, current, frequency and so on. Under normal and fault transient conditions of power system, STATCOM will adjust corresponding parameters, which may affect the action of protection and cause override or refusal of action. This requires the protection to have adaptive function to adapt to the influence of rapid change. In foreign relay protection systems, the theoretical analysis and Simulation of the impact of STATCOM on adaptive protection put forward an idea for us: apply adaptive protection in the line to reduce the impact of rapid adjustment of coefficient parameters on relay protection. In addition, the setting of adaptive protection time, control mode and economy of different protections must also be fully considered.
Zhuhai Sinopak Electric Ltd. provides high-quality STATCOM. If you are interested in our products, please contact us:daniel.wu@sinopakelectric.com.