CAJ | 학술논문

压电换能器是常用的电声和声电能量转换器件。根据压电换能器在机电谐振状态下显容性的电学阻抗特征，分别研究发射端和接收端压电换能器的阻抗变换问题。在发射端，着眼于消除换能器的容性无功功率，以减轻发射电源的负担，同时能够根据需要提供发射超声波所需要的有功功率；在接收端，着眼于消除等效输出阻抗的容性虚部，并减小实部，以便当负载电阻变动时，能够获得相对稳定的输出电压。给出实现上述阻抗变换的LC网络结构和参数计算方法，并以天然海水为介质、以压电超声换能器为电声和声电转换器件，搭建水下无线电能传输实验装置，以检验阻抗变换效果。实验结果证明了所提阻抗变换技术的有效性。
압전환능기시상용적전성화성전능량전환기건。근거압전환능기재궤전해진상태하현용성적전학조항특정，분별연구발사단화접수단압전환능기적조항변환문제。재발사단，착안우소제환능기적용성무공공솔，이감경발사전원적부담，동시능구근거수요제공발사초성파소수요적유공공솔；재접수단，착안우소제등효수출조항적용성허부，병감소실부，이편당부재전조변동시，능구획득상대은정적수출전압。급출실현상술조항변환적LC망락결구화삼수계산방법，병이천연해수위개질、이압전초성환능기위전성화성전전환기건，탑건수하무선전능전수실험장치，이검험조항변환효과。실험결과증명료소제조항변환기술적유효성。
Piezoelectric transducers are common devices for electricity-sound conversion and sound-electricity conversion. Electrical impedance transformation methods for the transmitting transducer and the receiving transducer were respectively studied, according to the electrical impedance characteristic that the piezoelectric transducer is capacitive when it works under the resonant state. On the transmitting side, electrical impedance transformation was aimed at eliminating capacitive reactive power in order to reduce the burden of the power source and providing active power for emitting ultrasonic waves as required, while on the receiving side, eliminating the capacitive imaginary part and decreasing the real part of the equivalent output impedance were mainly considered, with the purpose of getting relatively stable output voltage when the load resistance changed. Structures of the LC impedance transformation network and calculating methods of the parameters were presented in order to achieve these purposes. To examine the effects, an experimental setup of wireless power transfer system under water was established. Nature seawater was used as the ultrasound medium and piezoelectric ultrasonic transducers were used as devices for electricity-sound and sound-electricity conversions. The experimental results verify the efficiency of the proposed impedance transformation techniques.