自主式混合型多輸入擷能電路

壓電材料因其具有響應速度快、低工作電壓以及在微致動器等應用上的高效率，而受到重視。亦可由機械振動能量轉換為電能引起注意，然而它的輸出功率過低是此應用發展之障礙也使其無法成為再生能源之主流。本研究提出電源管理電路設計來處理壓電材料產生的電能。由於壓電材料的低功率輸出，該電源管理電路使用之零件數必須精簡，並且任何時候輸出均需被使用與收集。本研究提出了一種複合式升壓轉換器，其經由壓電材料產生的電能可結合儲能電池，以滿足負載所需的電壓。這種複合式轉換器將於壓電材料的輸出電壓太低而無法驅動負載的時候運作。但輸出的電壓足夠時，則由材料單獨供給輸出。最後，如果壓電材料可以產生夠高的電壓，另一個升壓轉換器將會啟動而向負載供電，並為電池充電。這三種模式的電源管理設計，可應用全範圍的壓電材料輸出電壓。本研究還提出了一種控制電路，用於控制轉換器的模式和開關。這是透過多個電壓比較器和PWM產生器設計而成。每個比較器及在不同輸入電壓下之效率皆有公式推導。負載電路模式與複合式模式比較，並探討需選擇特定模式之作動時機。整體控制電路之設計及控制訊號產生現象皆有說明及驗證。

關鍵字

複合式轉換器；電源管理電路；再生能源

並列摘要

Piezoelectric materials have been a huge interest to the academic community due to its vast possibilities. Besides having a fast response, low operating voltage and greater efficiencies for microactuator applications, its mechanical vibration to electric energy conversion can have various applications where harvesters has to be built in a smaller scale. However, its low power output has been a hindrance to it joining the mainstream of energy harvesting methods at present. This study explores and proposes a circuitry design for power management of the electrical energy given by piezoelectric materials. Because of the low-power output nature of these materials, the component count has to be kept low and its output has to be harvested at all times. This research proposes a Hybrid Converter where the power from the piezoelectric can be combined with a supporting battery to achieve a desired voltage for the load. This converter should work in periods where the voltage output from the material is too low to provide the desired output. However, if it is enough, the battery is disconnected and the material alone powers the output through the Supply Converter. And finally, if the voltage from the piezoelectric is more than high enough, another boost converter, the Charge Converter, is connected in parallel to the Supply Converter to simultaneously power the load and charge the battery. This completes the three-mode power management design for the whole range of power output from the piezoelectric. The research also proposes a control circuit for controlling the modes and switches for the converters. This is done through multiple comparators as voltage detectors and PWM generators. This research presents the formulae for each converter and their efficiencies at different input voltages. The Supply Converter is compared to the Hybrid Converter to see when should the system choose to run a specific mode. The whole circuit with the converters and control circuitry are presented in the end with the waveforms produced.

並列關鍵字

hybrid converter ； power management ； energy harvesting

參考文獻

[1] Rudolf Severns and Gordon Bloom, “Modern DC To DC Switch-mode Power Converter Circuits”, pp. 156-159, 235-240, 226-229, 1985.

[2] Marian Kazimierczuk and Dariusz Czarkowski, “Resonant Power Converters”, pp. 459, 477, 485, 2011.

[5] A. Prodic and D. Maksimovic, “Digital PWM Controller and Current Estimator for a Low-Power Switching Converter”, Department of Electronics and Computer Engineering, Colarado University, 2000.

[6] K. Siri, C.Q. Lee and T.F. Wu, “Current Distribution Control for Parallel Connected Converters”, IEEE Transactions on Aerospace and Electronic Systems, Vol. 28, No. 3, July 1992.

[8] Abraham Pressman, “Switching Power Supply Design”, 2009.

國際替代計量

自主式混合型多輸入擷能電路

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