A Controlled Conditioning Interface Unit for Dielectric Elastomer Generator

Dielectric elastomer (DE) generator (DEG) employs a soft capacitive transducer. This transducer is mainly used to convert ambient mechanical motion into electricity. The amplitude of the converted electrical signal is analogous to the magnitude of the mechanical motion. However, the inherently unpredictable nature of ambient mechanical motion causes instability in the energy conversion process. This article aims to develop a controlled conditioning unit, which is to be interfaced with DEG to eliminate this instability. This article generalizes a previously reported conditioning circuit with the help of a proportional and integral (PI) controller under the DEG domain to make the energy conversion process stable. Indeed, the overall analysis is carried out in two different stages. At first, an electromechanical prototype for DEG is designed, which is responsible for converting mechanical motion into a corresponding electrical signal. Second, the generated electrical signal is processed through a conditioning circuit, which constitutes a regulator followed by a switching mode converter. Intuitive analysis of stability is presented for different magnitudes of mechanical motion and for different dynamic resistive loads. As the output voltage is found to vary with the DEG dynamics and resistive load, the inclusion of a controller to the conditioning interface unit is essential for constant voltage application. The experimental investigation shows that the DEG, along with the controlled conditioning unit, could maintain different desired quasi-constant output voltages in spite of variation at mechanical source and electrical load.