As the uninterruptible power supply in parallel in the system in all digital control mode, the modulation ratio linear changes in the output voltage is not smooth, at the same time, the voltage detection resolution, the phase synchronization control accuracy and SPWM drive pulse The impact of the dead zone will make the parallel UPS system uninterruptible power supply output voltage amplitude, frequency and phase there is a slight difference. This difference in a single UPS uninterruptible power supply independent operation of its output voltage characteristics of not too much impact, but more than one parallel work, the average load sharing system has a more significant impact, and the corresponding cause of the power module The active, reactive circulation and harmonic circulation.
In order to analyze the current sharing characteristics and circulation conditions of the parallel system under the influence of the above factors, the UPS parallel power supply is taken as an example in parallel. The simulation results show that the common load is almost no-load. The main circuit is a half-bridge inverter circuit when the simulation is carried out. The parameter and control system parameters are the filter inductor and the filter capacitor, and the common load is purely resistive. UPS uninterruptible power supply are in open-loop voltage control.
Crystal light box (also known as acrylic light box): side light guide design, uniform light; Transparent crystal frame: when the light box is lit, it is bright and beautiful all around; Ultra thin: the thickness is only 8mm - 12mm; LED light source: more safe and energy-saving, longer life, easy to change pictures; Convenient installation: mainly table type, hanging type and wall mounted type; It is applicable to all kinds of high-end places: clubs, hotels, bars, restaurants, chain stores, wedding photo studios, interior decoration, company signs, gift displays, window displays, exhibits, home decoration photo frames and other places.
Advantages:
1. It can be made small and exquisite;
2. Large and small content can be customized, which is convenient, flexible and designable
3. The overall appearance is more beautiful than other light boxes
4. It is convenient to make and change the display content.
Slim Acrylic Light Box,Acrylic Led Light Box,Restaurant Menu Board,Magnetic Electronic Advertising
Guangzhou Jinshiming advertising equipment Co., Ltd , https://www.jsmlightbox.com