Numerical Study for Zero-Power Maglev System Inspired by Undergraduate Project Kits

Abstract

The single-axis maglev system is increasingly popular as undergraduate project kits over the recent years. Though it is simple and instructive, the large current in the electromagnet leads to the overheating problem. In order to enhance the energy-saving performance as well as the controller performance, this work compares three geometric modifications on the iron core, the upper permanent magnet and the floating permanent magnet for the maglev system. Four target cases are defined to incorporate the geometric modifications and are solved numerically. Moreover, the numerical solutions are carefully analyzed in terms of the zero-power force, the controller-gain requirement and the saturation current. Consequently, two approaches, i.e., extending the iron core and enlarging the floating magnet, can improve both the zero-power force and the controller-gain requirement and are highly recommended for the zero-power maglev system. On the contrary, though the upper magnet can improve the zero-power force, it significantly raises the controller-gain requirement and accelerates the saturation of the iron core. INDEX TERMS Zero-power maglev, electromagnetic suspension, permanent magnets, numerical simulation. FIGURE 2. Magnetic field (magnitude of the magnetic flux density) around the maglev system of Case 0 with I = 0 A.

Electronic Nonlinearity of Full-Bridge PWM Inverter for Zero-Power PEMS System

“…Furthermore, since 𝐹 is linear with 𝑖 𝑀𝑁 [14], the large sensitivity change about the zero current (e.g., around 1700/70 ≈ 24.3 times for 100 kHz) will significantly undermine the control stability of the zero-power PEMS system.…”

“…Mizuno and et al [13] developed an active vibration isolation system with an infinite stiffness against disturbances based on the zero-power PEMS technology. Zhang and et al [14] numerically optimized the geometry for the zero-power PEMS system as undergraduate project kits in terms of the zero-power force and the controller-gain requirement. Yalcin and et al [10] proposed linear-matrixinequality (LMI) structures based on H∞ and H2 control approaches for 3-DoF micro vibration isolation with zeropower problem.…”

Semi-Active Magnetic Levitation System for Education

“…This experiment suggested a positive learning experience from the involved students [21,22]. It seems this educational experiment has motivated other researchers to pursue similar investigations, striving to construct their own low-cost magnetic levitation systems [23][24][25]. This paper's main contribution is to show how to construct a novel low-cost magnetic levitation system for educational purposes.…”

Close-Loop Current Control With Current-Sensing Resistor for Electromagnet Driven by Full-Bridge PWM Inverter

“…AMB is famous for no contact and eliminates unwanted friction and lubrication so that AMB significantly promotes the high-speed rotating machinery [3]. Moreover, PEMS takes advantage of the Nd-Fe-B permanent magnet to reduce the power consumption of the electromagnet and enables the zero-power suspension [4]. Ren and et al [5] achieved fast and stable levitation of an AMB rotor by compensating for system uncertainties via proper design of interval type-2 membership functions.…”

“…The current through the electromagnet plays an important role [8] in the robustness of AMB [9] and PEMS [4,8]. However, the electromagnet possesses a large inductance that leads to the large time constant; besides, the tiny turn-off delay of the full-bridge PWM inverter results in the nonlinear current-duty cycle characteristic around the zero current [10].…”