Study on the Broadband Impedance Model of a Piezoelectric Energy Harvester for Nanoelectronic Systems

A nanopower generator is a complicated system and contains multiple interference sources. Thus, it is crucial to establish an integrated impedance model that considers the coupling of stator and rotor impedances to deeply analyze the electromagnetic interference (EMI) transmission mechanism. This paper established a broadband lumped parameter general model considering the stator impedance rotor impedance, and stator/rotor coupling effects. First, the model treats the motor as a multi-port network “black box,” and then uses the Z-matrix to describe the motor’s field impedance characteristics and gives the specific measurement and calculation methods of the parameters. Second, the impedance error expression ignoring the stator/rotor coupling derived to obtain the simplification condition of the three-phase model. Finally, a broadband general circuit model based on error evaluation is proposed. The practical test results show that the model has characteristics of high precision, low complexity, and strong universality. The proposed modeling method can provide a powerful guarantee for EMI research of the nanopower generator.