Electric generator using a triangular diamagnetic levitating rotor system

Abstract

This paper describes a feasibility study of creating a small low friction and low maintenance generator using a diamagnetically stabilized levitating rotor. The planar rotor described in this paper uses a triangular configuration of magnets that generates emf by passing over coils placed below the rotor. Equations were developed to predict the generated emf from coils with two different coil geometries. Additionally, this paper provides a method for estimating optimal coil size and position for the planar rotor presented for both segmental arc and circular coils to obtain maximum power output. Experiments demonstrated that the emf generated in the coils matches well with the predicted wave forms for each case, and the optimization theory gives good prediction to outcome of induced waveforms. For the segmental arc coil design, the induced emf was 1.7 mV at a radial frequency of 21.8 rad/s. For the circular coil design, the emf was 1.25 mV at a radial frequency of 28.1 rad/s.

Diamagnetically Levitating Three Phase Motor with Optical Feedback Control

“…This article discusses one such novel application of levitating systems, of that of a power delivery device, a levitating brushless DC motor with optical encoder system to measure its frequency. The same concept of using a triangular diamagnetic levitation rotor system for a generator application is extended here for a low speed motor application (Ho and Wang 2009). The motor system presented in this article possesses several advantages over traditional electrical motor systems.…”

“…The approximate mass of the rotor with magnets is 2.56 grams. A triangular design has theoretical simplicity, stability, and the possibility to either generate three phase current or use three phase current to power the device (Ho and Wang 2009). The permanent suspending magnet is visible in Figure 8a as the shiny cylindrical magnet mounted on a wooden block and attached to a screw which can change the vertical distance the levitating rotor.…”

“…As seen in Figure 7, the nine motor coils are grouped into three different phases which are evenly distributed around the levitating rotor. They act as a stator driving the levitating rotor around the vertical (central) axis (Ho and Wang 2009;Beer and Johnston 1998). The figure shows how the coils are grouped into three phases: phase one consists of coils 1, 4, and 7; phase two consists of coils 2, 5, and 8; and phase three consists of as 3, 6, and 9.…”

“…But now, commercially available neodymium boron ferrite magnets allow creating applications involving diamagnetic materials without using superconductors or electromagnets. Diamagnetic levitating systems have many applications (Ho and Wang 2009). They are used in microgravity experiments with small animals (Berry and Geim 1997;Simon et al 2001;Griffths 1999) and other superconductivity experiments such as superconducting bearings, gravimetric sensors (Mamlis et al 1997), superconducting frictionless transport method (Moon 1994;Mamlis 2001) and diamagnetic particle traps (Kitamura et al 2001;Young 1992).…”

Levitation Characteristics Analysis of a Diamagnetically Stabilized Levitation Structure

“…In recent years, some applications based on diamagnetically stabilized levitation have been reported, such as sensors [ 4 , 5 , 6 ], actuators [ 7 ], and vibration energy harvesters [ 8 , 9 , 10 ]. Hilber et al [ 11 ] presented a sensor based on diamagnetically stabilized levitation, which can be used to measure the density and viscosity of fluids in microfluidic systems.…”