Design Of High Power Of Digital Ultrasonic Generator

By the ultrasonic effect, the amount of traditional Chinese medicine extraction can effectivelyincreases. Limited by the output power of ultrasonic equipment and the inconvenience of operationin the industrial field, the application of ultrasonic technology in the traditional Chinesemedicine extraction has not been scaled and industrialized. In recent years, with the developmentof the ultrasonic transducer technology and the high power of digital generator, it is possible toindustrialize the ultrasonic equipment in the field of traditional Chinese medicine extraction. Thispaper mainly do some research on high power digital ultrasonic generator. The result may be usefulto application of traditional Chinese medicine extraction.In this paper, the matching circuit of ultrasonic generator is considered. Based on the staticmatching theory, a new concept of matching-dynamic is proposed, which considers the transducerand matching circuit as a whole system and concludes the dynamic coupling frequency. The systemis resonance when the output frequency of generator is equal to the dynamic couplingfrequency,which is the theory basis of automatic frequency searching and tracking.A control algorithm of digital ultrasonic generator is designed for the load of Chinese medicine.During the frequency searching and tracking, A Integral-separation PI algorithm is used to makesure the current through the transducer is constant. A method of variable step for resonant frequencysearching is proposed. According to the different levels of load, corresponding frequency trackingalgorithms are designed, that helps general tracking algorithm is established.The generator designed in the paper has the communication interface based on Modbus_RTU.It is feasible to achieve the parameters setting of multiple power remotely by using Modbus_RTU.The ultrasonic equipment has completed a successful project of the traditional Chinese medicineextraction in He Nan Wan Xi pharmaceutical factory. The result show that the ultrasonic equipmentcan greatly increase the extraction quantity of some certain Chinese herbal medicine. So thelarge-scale application of power ultrasonic technology in the field of traditional Chinese medicinehas a board prospect.