A Driving Power Supply for Piezoelectric Transducers Based on an Improved LC Matching Network

Abstract

In the ultrasonic welding system, the ultrasonic power supply drives the piezoelectric transducer to work in the resonant state to realize the conversion of electrical energy into mechanical energy. In order to obtain stable ultrasonic energy and ensure welding quality, this paper designs a driving power supply based on an improved LC matching network with two functions, frequency tracking and power regulation. First, in order to analyze the dynamic branch of the piezoelectric transducer, we propose an improved LC matching network, in which three voltage RMS values are used to analyze the dynamic branch and discriminate the series resonant frequency. Further, the driving power system is designed using the three RMS voltage values as feedback. A fuzzy control method is used for frequency tracking. The double closed-loop control method of the power outer loop and the current inner loop is used for power regulation. Through MATLAB software simulation and experimental testing, it is verified that the power supply can effectively track the series resonant frequency and control the power while being continuously adjustable. This study has promising applications in ultrasonic welding technology with complex loads.

Modeling of Ammunition Dynamic Pressure Measurement Chain in Ballistic Tests

“…For the modeling of the HPI GP6 piezoelectric transducer, the model called Butter worth-Van Dyke (BVD) was considered, as recommended by the IEEE Standard on Pie zoelectricity (ANSI/IEEE Std 176-1987) [19]. The BVD model is useful for the analysis o the electrical performance of piezoelectric transducers [20] and can be used in the design and optimization of piezoelectric devices [21][22][23][24]. The BVD model circuit consists of a re sistor, an inductor and a capacitor in series (𝑅 𝑚 , 𝐿 𝑚 , 𝐶 𝑚 ), all connected in parallel with a second capacitor (C 0 ), as shown in Figure 5.…”

“…From the impedance equation of the BVD model ( 2), its elements can be determined employing the least squares curve fitting of the impedance obtained experimentally, unlike other approaches, in which the determination of the elements of the electric circuit takes place by means of parametric equations dependent on the magnitude of the impedance at specific frequencies [22,24,25], or even by employing physical parameters that are characteristic of the piezoelectric material of the transducer [26]. For this, we used a Keysight E4900A impedance analyzer, which basically excites the transducer through a voltage of 100 mV with a variable frequency and measures its response, providing the reactance and resistance for a frequency range from 1 kHz to 100 kHz.…”