Power conditioning techniques for energy harvesting

Abstract

Over the last 10 years the most dramatic progress in energy harvesting has concerned the power conditioning sub-system. Whilst the mechanical components and transducers have seen incremental improvements, often related to modelling and understanding behaviour, the power conditioning systems have undergone revolution: from simple peak rectifiers to complex topologies and control, with several examples integrated onto ICs. In this chapter the basic interactions of the dynamic mechanical and electrical system are described, and it is suggested that analysing the power factor at the input to the power conditioning system can be a useful tool in understanding behaviour. The benefits of electrical tuning are then described: this is an important topic, which the authors believe will be a key direction of future research. The chapter also gives an overview of published circuits for electromagnetic, piezoelectric and electrostatic transduction mechanisms.