A continuously rotating energy harvester with maximum power point tracking

Abstract

In this paper, we analyse and demonstrate an energy harvesting generator powered by continuous rotation, using gravitational torque to enable single point attachment. The electro-mechanical behaviour of the generator is presented, alongside experimental results from an implementation based on a conventional DC motor. The off-axis performance is also modelled. The design and experimental results for an adaptive power processing circuit are also presented, as the first demonstration of maximum power point tracking for a motion energy harvester.

A methodology for low-speed broadband rotational energy harvesting using piezoelectric transduction and frequency up-conversion

“…The ball rolls back and forth along the track with regard to the influence of gravity, impacting two piezoelectric beams fixed alongside the track once per cycle. Similarly, Toh et al presented a continuous rotational electromagnetic energy harvester using gravitational torque [20]. An off-centred mass was attached on a conventional DC generator to create gravitational torque.…”

“…In terms of energy transduction for rotational energy harvesting, the dominant mechanisms are piezoelectric [19,15], electromagnetic [20,23] and electrostatic [21]. Their pros and cons are extensively investigated in vibration energy harvesting [10,24].…”

“…Compared to the amount of energy collected by harvesters, the rotational energy source can be divided into two categories -unlimited and limited. For unlimited sources, like rotating wheels and machines, the energy provided by the host is tremendous compared with the energy collected by the harvesters, and the rotational motion of the host is not significantly affected by the harvesters, so the main considerations are the amount of energy that can be collected from the source [20], the operating bandwidth [19], and the compactness of the device [15]. For limited sources, such as miniature airflow turbines, the energy stored by the rotating host is modest and the harvesters should exploit the energy to the largest extent.…”

Energy harvesting technologies for wireless sensors in rotating environments

“…In the case where it is not possible to utilize the relative motion between a stationary and rotating system, a pendulum that is joined at the rotation axis of the rotating system can be used. As Toh et al reports in [9] they use an eccentric weight and DC motor to harvest energy. In cases where the harvester cannot be placed in center of the rotation axis as, the gravitation can be utilized to induce a pendulum motion as the whole harvester is rotated eccentrically, see also [10].…”

Energy harvesting and wireless data transmission system for rotor instrumentation in electrical machines

“…when the load and armature resistances are equal. The system has an energy conversion stage composed of a boost converter to perform the MPPT algorithm and a buck converter to regulate the DC link at 3.3 V. The system was characterised on a test bench and generated about 60 mW at 2000 rpm [10]. This solution has limited power and requires a DC generator, energy conversion and energy storage circuitry leading to a complex system with large volume.…”