The Design Of High Power Ultrasonic Inverter Power

The ultrasonic plastic welding of the modern mechanical manufacture is becoming a promising manufacturing technology with the increasing usage in many areas. High-quality ultrasonic inverter power supply is necessary for realizing high-quality and high-efficiency ultrasonic metal welding. Moreover, it is a key step to find the right frequency’s for an excellent ultrasonic inverter power supply.The resonance frequency of the ultrasonic transducer includes the serial resonance frequency and the parallel resonance frequency. The serial resonance frequency is called mechanical resonance frequency, which is the optimal working frequency. The efficiency of the ultrasonic transducer is the highest at the serial resonance frequency. Therefore, the ultrasonic inverter power should work at this frequency.This thesis studies the working property of the resonance circuit under the ground of the detailed analysis of the mechanical and electrical characteristics of the ultrasonic transducer. The aim is to develop a kind of high-quality and high-efficiency inverter power supply. The main contents are as follows:(1) Based on the equivalent principle between the mechanics and electrics, the equivalent circuit property and the characteristic impendence of the ultrasonic transducer are analyzed and computed. The conclusion is that the ultrasonic transducer can balance the self-body capacitor by the matching inductor.(2) The simulation results of the circuit shows that the matching inductor not only can balance the self-body capacitor, but also make the vibration effect better by stepping up the voltage using the serial resonance.(3) The control type of the ultrasonic inverter power supply is analyzed and the new control method is proposed. The working frequency is controlled by the manual-adjust potentiometer. The current and voltage are shown on the transducer and the optimal frequency is found, which is the working frequency.(4) The details of the controlled rectifier module and the DC/AC inverter module are introduced. The design and the manufacture of the key devices, such as filtering inductor, matching inductor and the main transformer are presented in detail.(5) The method of searching the serial resonance frequency of ultrasonic transducer is introduced mainly in the experiment. The experimental results show that the design of circuit is reliable and has the strong adaptability and the high efficiency. Therefore, this design plan has the good applicable and popular value.