Dobavitelji naprav za povratno zanko energije vas opominjajo, da se frekvenčni pretvorniki pogosto uporabljajo in so glede na napetostne nivoje razdeljeni na nizkonapetostne frekvenčne pretvornike in srednje visokonapetostne frekvenčne pretvornike. Namen in zahteve posameznih panog se razlikujejo.
1. Uporaba frekvenčnih pretvornikov pri varčevanju z energijo pri pretvorbi frekvence
The energy-saving aspect of frequency converters is reflected in the application of fans and pumps. After adopting variable frequency speed regulation, the energy-saving rate of fans and pump loads is 20% to 60%, because the actual power consumption of fans and pump loads is basically proportional to the third power of the speed. When the average flow rate required by users is small, fans and pumps use variable frequency speed regulation to reduce their speed, which has a significant energy-saving effect. However, traditional fans and pumps use baffles and valves for flow regulation, with the motor speed remaining basically unchanged and the power consumption not changing much. According to relevant statistics, the electricity consumption of fan and pump motors accounts for 31% of the national electricity consumption and 50% of industrial electricity consumption. The use of variable frequency speed regulation devices on such loads is of great significance. Currently, successful applications include constant pressure water supply, various types of fans, central air conditioning, and hydraulic pump variable frequency speed regulation.
2、 Application of frequency converter in automation system
Due to the built-in 32-bit or 16 bit microprocessor in the frequency converter, which has various arithmetic logic operations and intelligent control functions, the output frequency accuracy is 0.1%~0.01%, and it is equipped with complete detection and protection links, so the frequency converter is widely used in automation systems. For example, winding, stretching, measuring, and wire guiding in the chemical fiber industry, flat glass annealing furnaces, glass kiln mixing, edge drawing machines, bottle making machines in the glass industry, automatic feeding and batching systems for electric arc furnaces, and intelligent control of elevators.
3、 The application of frequency converters in improving process level and product quality
Variable frequency drives are widely used in various mechanical equipment control fields such as transmission, lifting, extrusion, and machine tools. They can improve process level and product quality, reduce equipment impact and noise, and extend equipment service life. After adopting frequency conversion speed control, the mechanical system is simplified, operation and control are more convenient, and some can even change the original process specifications to improve the functionality of the entire equipment. For example, in textile and many other industries, the temperature inside the shaping machine is adjusted by changing the amount of hot air sent in. Circulating fans are usually used for conveying hot air, and since the fan speed remains constant, the amount of hot air sent can only be adjusted by the air damper.
Če nastavitev zračnih vrat ne uspe ali ni pravilno nastavljena, bo stroj za oblikovanje izgubil nadzor in bo to vplivalo na kakovost končnega izdelka. Ko se ventilator za kroženje zraka zažene z visoko hitrostjo, je obraba med pogonskim jermenom in ležajem zelo huda, zaradi česar je pogonski jermen potrošni material. Po uporabi regulacije hitrosti s frekvenčnim pretvornikom je mogoče doseči nastavitev temperature z avtomatskim prilagajanjem hitrosti ventilatorja prek frekvenčnega pretvornika, kar reši problem kakovosti izdelka. Poleg tega lahko frekvenčni pretvornik enostavno zažene ventilator pri nizki frekvenci in nizki hitrosti, zmanjša obrabo med pogonskim jermenom in ležaji, podaljša življenjsko dobo opreme in prihrani 40 % energije.
4. Uporaba frekvenčnega pretvornika za doseganje mehkega zagona motorja
Težak zagon motorjev ne povzroča le resnega vpliva na električno omrežje, temveč tudi zahteva prekomerno zmogljivost omrežja. Visok tok in vibracije, ki nastanejo med zagonom, povzročajo znatno škodo na pregradah in ventilih, kar negativno vpliva na življenjsko dobo opreme in cevovodov. Po uporabi frekvenčnega pretvornika bo funkcija mehkega zagona frekvenčnega pretvornika povzročila, da se zagonski tok spremeni iz nič, največja vrednost pa ne bo presegla nazivnega toka, kar zmanjša vpliv na električno omrežje in potrebo po napajalni zmogljivosti, podaljša življenjsko dobo opreme in ventilov ter prihrani stroške vzdrževanja opreme.