طراحي مدار واسط تطبيقي برداشت انرژي براي آرايه اي از مبدل هاي پيزوالكتريكي

چكيده انگليسي :

Design of an Adaptive Energy Harvesting Interface Circuit for Array of Piezoelectric Transducers Mostafa Sharifian mostafa sharifian@ec iut ac ir August 12 2020 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Dr Nasrin Rezaei Assist Prof n rezaei@iut ac ir AbstractOne of the main challenges of using wireless sensor networks WSN is their power supply Due to limitedcharge environmental concern and the difficulty of replacing the batteries energy harvesting is a promisingsolution to develop self powered wireless sensor nodes One of the ambient energy sources is vibration energy which can be extracted and converted to electrical power by piezoelectric energy harvesters The main challenge in using these harvesters is their resonant performance hence these harvesters receive suit able power only at their resonant frequency and the power drops extremely at other frequencies Therefore using the array of piezoelectric energy harvesters with different resonance frequencies can enhance the gener ated electrical power Furthermore it also improves the reliability of the system especially under some weakvibrations Having a correct understanding of ambient environmental vibrations and proper resonant frequencyselection is essential for extracting maximum power from the array of energy harvesters Therefore in thesecond chapter of this thesis a criterion for selecting the resonant frequency of an energy harvester based onamplitude and frequency of vibration in a multi frequency environment is provided Designing a suitable interface circuit to get power from array of energy harvesters is another important chal lenge that should be addressed The limited size of the wireless sensor nodes and finite power density of energyharvesters necessitate that the interface circuit must be as small as possible and implemented as an integratedcircuit with low power consumption Also because ambient energy sources are often irregular or intermittent the interface circuit should receive maximum power from all array harvesters in any environmental vibrationconditions In this thesis a power processing circuit for an array of piezoelectric energy harvesters with different resonantfrequencies and time varying open circuit voltages is presented The proposed power processing circuit canreceive maximum power for all array elements independent of the harvester s open circuit voltage The pro posed control method only depends on the amount of the cantilever beam capacitance and vibration frequency Also in comparison with other interface circuits all passive capacitive elements are removed and the amountof shared inductive component is reduced to 100 uH saving space and fabrication costs Sharing different partsof the circuit for all transducers in arrays is another advantage of this structure which reduces the area The pro posed interface circuit extracts 1 57 times more power than a conventional full bridge rectifier based harvestingcircuit Another advantage of the proposed interface circuit is that it can be used for all energy harvesters thatdeliver maximum power at an optimal resistance load Hence the suggested circuit can be used for a hybridset that includes several different energy harvesters The proposed power processing circuit is designed andsimulated in 180 nm CMOS technology and chip layout with a 0 4 mm2 area is also submitted for fabrication

شريفيان، مصطفي

طراحي مدار واسط تطبيقي برداشت انرژي براي آرايه اي از مبدل هاي پيزوالكتريكي

شبكه هاي حسگر بي سيم , برداشتگرهاي انرژي پيزوالكتريكي آرايه اي , فركانس رزونانس , مدار واسط خودتوان تطبيقي , مدار مجتمع