Which is better, electrostatic or piezoelectric energy harvesting systems?

[摘要] This paper answers the often asked, and until now inadequately answered, question of which MEMS compatible transducer type achieves the best power density in an energy harvesting system. This question is usually poorly answered because of the number of variables which must be taken into account and the multi-domain nature of the modelling and optimisation. The work here includes models of the mechanics, transducer and the power processing circuits (e.g. rectification and battery management) which in turn include detailed semiconductor models. It is shown that electrostatic harvesters perform better than piezoelectric harvesters at low accelerations, due to lower energy losses, and the reverse is generally true at high accelerations. At very high accelerations using MEMS-scale devices the dielectric breakdown limit in piezoelectric energy harvesters severely decreases their performance thus electrostatics are again preferred. Using the insights gained in this comparison, the optimal transduction mechanism can be chosen as a function of harvesting operating frequency, acceleration and device size.

[发布机构] Department of Electrical and Electronic Engineering, Imperial College London, London, United Kingdom^1;Alphabet Energy, Eden Landing Rd, Hayward; CA, United States^2;Buskerud and Vestfold University College, Grønland 58, Drammen; 3045, Norway^3;University of California, Berkeley; CA, United States^4

[效力级别] 能源学

[关键词] Battery Management;Energy harvesting systems;Modelling and optimisation;Operating frequency;Piezoelectric energy harvesters;Piezoelectric energy harvesting systems;Piezoelectric harvester;Transduction mechanism