- 學位論文
低頻壓電陶瓷之驅動控制電路設計研究
Design of Low-Frequency Driving Circuitry for Piezoelectric Actuators
摘要
本文係針對低頻壓電陶瓷材料之單相共振式換流器設計其驅動控制架設計分析內容主要包括，延遲電路、濾波諧振電路及反饋控制電路部份。延遲電路之設計直接影響功率級電路是否能在較佳的情況下切換不致燒毀，而延遲的時間通常僅介於微秒至奈秒(micro ~ nano)等級，在設計時往往會出現一些不必要的雜訊及飄移現象，而這些脈衝干擾(glitch)在高頻時幾乎對系統不會有任何影響，但在低頻的設計中，這些訊號將造成系統的誤判而造成功率級電路的燒毀，故設計時更需謹慎。由磁學分析式(法拉第定律)可清楚的看出，欲使用換流器架構設計出一低頻之驅動電路需要取得較大的濾波電感、電容，以獲得較佳之諧振波輸出。且工作頻率愈低，則所需之感抗值愈高。然而高容抗值之電容器並無法自行研製，且現有電容、電感器之容抗、感抗值無法滿足，故透過濾波電感值之規劃及設計分析以期能達到期望之諧振輸出，符合驅動匹配機構所需之低頻共振頻率。另本研究之驅動機構為壓電陶瓷，而壓電材料受熱、電、力等效應後所產生之參數變化、物理特性不明確等因素，以致諧振波輸出之驅動效率不佳，故另設計反饋控制電路以期達到更高之輸出效率。經實驗證明，本文所提出之低頻壓電陶瓷共振式換流驅動控制架構，確實具有良好之驅動響應。
並列摘要
A driver design of single-phase resonant inverter is studied to satisfy various piezoelectric actuators operating at low frequency. Delay circuit, harmonic filter circuitry, and feedback control circuitry desing are the focus for the driver. The delay circuit is designed for the purpose of maintaining the power MOSFET switching under good condition and avoiding it burned out. Since the delay time is around microsecond to nanosecond, it often produces noise and glitch effect. This defect does not affect the system at high frequency significantly, but it may generate inaccurate signals so as to burn out the power MOSFET. Thus, comprehensive design of the delay circuit is important. By means of the Faraday’s law, a low-frequency driver based on the inverter structure needs large inductance and capacitance to obtain better resonant wave output. The capacitor of high impedance is unable to produce easily, and the available inductor and capacitor with high impedance is still not satisfactory for the driver. Hence, appropriate design of the filter inductance to match the resonant frequency is investigated obtain achieve expected resonant wave output. Because the piezoelectric ceramics is vulnerable to the change of heat, electricity, and stress, etc., the output function of the actuator degrades. Therefore, a feedback control design for the inverter is developed to gain better efficiency. Experiment verifies the performance of the developed low-frequency driving circuitry.