Analysis of spatial harmonics in a polyphase electrostatic induction micromotor

Abstract

This paper analyzes the influence on the force density of the spatial harmonics of the excitation voltage signal on each electrode of an electrostatic induction micromotor. We have used the lumped parametric equivalent circuit [7] and demonstrated that the spatial harmonics are attenuated from stator to rotor. Index Terms-Electrostatic induction micromotor, spatial harmonics, parametric equivalent circuit. I. NOMENCLATURE Symbol Name Unit a Height of dielectric a, air (m) b Height of dielectric b, rotor (m) C 1 Capacitance 1 (F/m) C 2 Capacitance 2 (F/m) G′ 2 Conductance 2 (S/m) G′ r Variable Conductance (S/m) k Number of waves per metre j Imaginary unity-S Slip-T t Force density tangential component (N/m 2) v Linear speed of mobile part (m/s) V Interelectrodic voltage (V) V 0 Supply voltage (V) V 1 Voltage in node 1 (V) V 2 Voltage in node 2 (V) ε a Permittivity of the dielectric a (F/m) ε b Permittivity of the dielectric b (F/m) ε eff Effective permittivity (F/m) ω Angular frequency of the signal (Hz) σ a Conductivity of the dielectric a (S/m) σ b Conductivity of the dielectric b (S/m) σ eff

Macroscale Electrostatic Rotating Machines and Drives: A Review and Multiplicative Gain Performance Strategy

“…The discrete nature of electrodes' effect on the potential waves may be analyzed piecewise with the Fourier analysis to determine the fundamental spatial components that produce torque. This spatial harmonic analysis was done for separately excited SEM design in [10] and [23] and has been analyzed in both macroscale and MEMS induction motors in [6], [24], [34], and [48]. Equations ( 8) and ( 9), when paired with spatial harmonic analysis, yield accurate results as verified by experimental measurements in [10] and [23].…”