How to apply intelligent capacitor in reactive power compensation

How to apply intelligent capacitor in reactive power compensation

Intelligent capacitor is an important milestone in the development history of reactive power compensation technology in power system. Smart capacitors are called smart products because they do not need the support of compensation controllers. Self generating - an independent reactive power compensation system. With zero crossing switching and automatic protection function, it is a major breakthrough in automatic reactive power compensation technology of low-voltage power. It has the advantages of simple structure, low networking cost, superior performance, convenient maintenance, etc. it can be flexibly applied to various low-voltage reactive power compensation occasions.

The switch in the intelligent capacitor has special technology of electromagnetic zero crossing switch. The deviation of zero crossing switch is less than 2.5. The inrush current of the switch is less than 2.5 times of the rated current. The intelligent control unit controls the switch to close at zero crossing voltage by detecting the voltage at both ends when the dynamic and static contacts of the switch are open; by detecting the current when the dynamic and static contacts of the switch are closed, it controls the switch to open and close at zero crossing to realize the function of "zero crossing switch", so that the inrush current generated when the low-voltage power capacitor is put into operation is very small, and the low-voltage power capacitor without arc is restored Runtime phenomena. Thus, the service life of low-voltage power capacitor and switch device is prolonged. It also reduces the impact of switching on the grid: improves the power quality of the grid.

When multiple intelligent capacitors are in line self-organizing reactive power compensation system, one host can be automatically generated, and the rest are slave machines, forming the automatic control work of low-voltage reactive power compensation system; when some slave machines fail, they will automatically exit without affecting the normal work of other intelligent capacitors; when the host machine fails, they will automatically exit, and a new host will be automatically generated on other slave machines The new system works normally; according to the principle of cycle switching, the capacitors with the same capacity are switched, while those with different capacity are switched according to the principle of capacity adaptive, so as to ensure that there is no oscillation in the switching process.

In the case of unbalanced three-phase load, the intelligent capacitor can adopt the combination of three-phase common compensation and three-phase separate compensation. According to the magnitude of the reactive power shortage of each phase, respectively switch on three-phase power supply to compensate the capacitor, in order to achieve the best reactive power compensation effect.

The intelligent capacitor has its own operation panel and LCD screen with complete display data, which can display distribution voltage, distribution current, distribution power factor, working current of the intelligent capacitor itself, capacitor shell temperature, etc.

The protection functions of the intelligent power capacitor include: over-voltage, under voltage, voltage loss and phase loss protection of the distribution network; over temperature protection of the power lead-in end; over-current sectional protection of each phase of the power capacitor; over temperature sectional protection of the power capacitor body.

The intelligent capacitor has the function of man-machine conversation. This is also an important technical means for operation and maintenance personnel to operate, debug and maintain intelligent capacitors. Intelligent capacitor can work normally only through man-machine conversation.