Application Of Small-gain Theorem Research Articles

Frequency-varying synchronous micro-vibration suppression for a MSFW with application of small-gain theorem

This paper presents a novel synchronous micro-vibration suppression method on the basis of the small gain theorem to reduce the frequency-varying synchronous micro-vibration forces for a magnetically suspended flywheel (MSFW). The proposed synchronous micro-vibration suppression method not only eliminates the synchronous current fluctuations to force the rotor spinning around the inertia axis, but also considers the compensation caused by the displacement stiffness in the permanent-magnet (PM)-biased magnetic bearings. Moreover, the stability of the proposed control system is exactly analyzed by using small gain theorem. The effectiveness of the proposed micro-vibration suppression method is demonstrated via the direct measurement of the disturbance forces for a MSFW. The main merit of the proposed method is that it provides a simple and practical method in suppressing the frequency varying micro-vibration forces and preserving the nominal performance of the baseline control system.

Application of Small-Gain Theorem in the Dead-Time Compensation of Voltage-Source-Inverter Drives

A simple and iterative algorithm is devised in this letter with the help of the small-gain theorem to determine the current polarities of pulsewidth-modulation voltage-source-inverter drives. Experimental results are also presented to show the effectiveness of the method when used in the dead-time compensation.