Small-scale wind energy harvesting, which can replace batteries to power small electronic devices and realize self-powered systems, has been extensively studied. To improve the working wind-speed range and output power of small-scale wind energy generation systems, we propose a synergetic hybrid piezoelectric and triboelectric mechanism for galloping wind energy harvesting. In this mechanism, a piezoelectric energy harvester (PEH) works in the vibration area and starts working at low wind speeds, while triboelectric nanogenerators work at the vibration boundaries and cooperate with the PEH at high wind speeds. The triboelectric nanogenerator boundaries can (1) constrain the maximum deformation of the beam at high wind speeds to avoid damage to the PEH, (2) increase the vibration frequency to enhance the electromechanical conversion efficiency, and (3) allow the PEH to have a low equivalent stiffness to work effectively at low wind speeds. A dynamic model is presented to characterize the synergetic hybrid piezoelectric–triboelectric wind energy harvester (SHPTWEH) and this is verified by experiments. The results show that the triboelectric nanogenerator boundaries greatly expand the effective working wind-speed range, and the total average power output by the prototype SHPTWEH was 0.24 mW at a wind speed of 14 m/s, which was 2.3 times that of the PEH alone.

Attributing to the unique feature of zero carbon emission, electric vehicles (EVs) are attracting increasing interest in recent years, but their reliability, particularly the reliability of their critical components, is still a matter of concern today. In order to address this issue, much effort has been made before to assess the reliability of drive motor in the EVs. However, drive motor and motor controller are logically integrated and requested to work as one system in the EVs. In contrast to the individual reliability analysis of them, the combined assessment of the two parts can provide a more reliable prediction to the reliability of the entire motor system. Moreover, both drive motor and motor controller are composed of multiple components. The structure, type, and characteristics of these components may affect the reliability of the motor system as well. But these issues have not been considered in the previous research. In order to fill this gap of knowledge, the reliability of the entire motor system of pure electric vans that includes both drive motor and motor controller is investigated in this paper. In the research, the theoretical failure rates of subassemblies and components in drive motor and motor controller are predicted first. Then based on the failure rate prediction results, the reliability of the entire motor system (comprising both drive motor and motor controller) is assessed. Based on the assessment results, some interesting conclusions with respect to the most vulnerable subassemblies and components in the entire motor system and the potential disadvantage of existing reliability research are finally obtained. It is deemed that these new findings will be of great significance to the future reliability design and maintenance of pure electric vans.

The wireless sensor network energy supply technology for the Internet of things has progressed substantially, but attempts to provide sustainable and environmentally friendly energy for sensor networks remain limited and considerably cumbersome for practical application. Energy harvesting devices based on the magnetoelectric (ME) coupling effect have promising prospects in the field of self‐powered devices due to their advantages of small size, fast response, and low power consumption. Driven by application requirements, the development of composite with a self‐biased magnetoelectric (SME) coupling effect provides effective strategies for the miniaturized and high‐precision design of energy harvesting devices. This review summarizes the work mechanism, research status, characteristics, and structures of SME composites, with emphasis on the application and development of SME devices for vibration and magnetic energy harvesting. The main challenges and future development directions for the design and implementation of energy harvesting devices based on the SME effect are presented.

The concept of green and sustainable development is driving the convergence of transportation systems and energy technologies. New energy harvesting technology (EHT) is an important way of the development in the green intelligent transportation system. Comparing with the power supply via batteries or cables, it has the advantages of convenient, sustainable, green and low carbon to harvest mechanical energy from the traffic environment and convert it into electrical energy to power the widely distributed small electromechanical systems. There are many studies on mechanical energy harvesting in traffic environment, few of them have comprehensively discussed these studies and their applications in the intelligent transportation. This paper first outlines the principles, methods, and energy management strategies of the mechanical energy harvesting in the traffic environment. The advantages, disadvantages, and applicability of various EHTs are comprehensively and systematically analyzed from vehicle and road dimensions. The applications of EHT was discussed includes: self-powered traffic control, self-powered vehicle-road collaboration and self-powered health monitoring of traffic infrastructure. Finally, the challenges and prospects of mechanical EHT and applications in the traffic environment are discussed. Mechanical energy harvesting in traffic environment has broad application prospects in intelligent transportation, while improving the output power and reliability of the energy harvesting system is the key to its wide application in intelligent transportation systems.