Research And Design Of Intelligent Ultrasonic Power For Casting

Incorporating ultrasonic-physics into the casting of aluminum alloy has a high potential to increase quality and fabrication efficiency. The load’s frequency will float during the process of aluminum alloy casting because of the harsh working environment, interference and disturbance. Conventional ultrasonic power has deficiencies of resonant frequency tracking, resonant power and power factor. In order to alleviate the above problems, it’s essential to design a new type of ultrasonic power for aluminum alloy casting.The mechanism of power ultrasonic on aluminum casting is analyzed. The importance of ensuring the stability of power ultrasonic to improve the performance of aluminum and the development of ultrasonic power is described. Recent research on requirements and the existing problems about aluminum casting ultrasonic power are also elaborated. To solve problems above, a novel design with power main circuit as AC-DC-AC structure and control circuit using TMS320F2809as the main control processor is proposed. The frequency generating circuit with high definition PLL chip AD9833is designed. The high-frequency transformer is implemented in detecting voltage to improve the tracking accuracy of the system.Research of the equivalent circuit of the piezoelectric ceramic derivation is done. Impedance admittance and frequency are analyzed based on equivalent circuit. The series resonant frequency is selected as the tracking frequency and series impedance matching circuit is designed. The resonant frequency changes with temperature and load fluctuations. To follow the resonant frequency, a novel control method combining fuzzy with PLL based on the difference of voltage and current phase is designed.Simulation and experiment show that the ameliorate increases the system’s tracking speed and tracking accuracy, improves the stability of ultrasonic power, and ensures the sysdem work on the optimal state.