Control Technology Of Ultrasonic Cleaning Power Supply

With the development of science and technology, ultrasonic engineering hasbeen widely studied and has a certain cross development with other subjects.Ultrasonic technology has a wide range of applications in national defense,industrial production and daily life. The research is divided into two aspects: powerultrasonic and ultrasonic testing. Ultrasonic cleaning power supply in this paperbelongs to the power ultrasonic. Compared to other cleaning methods, ultrasoniccleaning has an advantage of high efficiency, and can play an important role inindustrial production. But the current domestic research on high-power ultrasoniccleaning power supply is still relatively backward, so there is a need for furtherresearch on the power supply control technology.The piezoelectric transducer as the load of cleaning power supply is firststudied in this paper. As the drive object, the transducer has an equivalent transformin the electrical aspect, and its characteristics of the equivalent model are analyzed.Because the main property is capacitive, there is a further analysis to the matchingcircuit and an impedance test on the practical transducer. Finally, based on thecharacteristics of the load transducer, the topology of each unit power supply isdetermined.According to the power factor correction, the power control and the frequencytracking, the paper gives some power control strategies. APFC technology is joinedinto Boost unit, and the control parameters are designed by using the small signalmodel. For the frequency tracking technique, this paper proposes a fuzzy-PID multi-mode control which is based on the idea of ordinary PLL, to adapt to the changeableimpedance characteristics of the transducer. Then circuit topology and controlalgorithms are simulated by using MATLAB/SIMULINK, which verifies thefeasibility of the structure and the algorithm.The hardware of the ultrasonic cleaning power supply is designed in this paper,including the selection of power device, sampling circuit, signal processing circuit,drive circuit, high-frequency transformer and its corresponding protection circuit.The platform is built for the physical experiment. At last, the experimental resultsare analyzed and it verifies the feasibility of the APFC technique and the frequencytracking method.