Electromechanical modeling and designing of capacitive MEMS DC/AC interactive power inverter for renewable energy applications

This paper presents the electromechanical modeling and designing of a new concept micro-scale DC/AC interactive power inverter for renewable energy applications. The proposed power inverter is based on micro electromechanical systems (MEMS) technology to compete with commercial power electronics inverters, in terms of size miniaturization, generating pure and smooth sine wave output, efficiently regulating the frequency of output signal, consuming ultra low power, and sufficiently low cost. The proposed MEMS power inverter occupies an active layout area of 35 × 35 mm², with 455 µm thickness. It has a 50 Hz mechanical resonance frequency, and a 3.9 pF initial capacitance. The anticipated MEMS power inverter is capable of converting DC voltages, as low as 0.5 V from a single solar cell, or as higher voltage as 24 V from a photovoltaic module. The capacitive design concept of the proposed MEMS power inverter leads to zero power consumption. The frequency and waveform shape of the converted DC/AC signal matches with the AC signal of a power grid, with 6 % observed conversion efficiency.