The list of photovoltaic (PV) applications grows longer every day with high consideration for system efficiency. For instance, in spite of many recent PV aircraft designs, aircraft propulsion was mainly reserved for nonelectric motors. Lately, the Solar Impulse flight across the world shows the possibilities of larger PV powered electric aircraft. In order to obtain this goal efficiency of flight, PV conversion, power converters and electric drives have to be maximized. These demands led to a 63.4 m wingspan. The purpose of this paper is to present that PV power could be used for improving the performance of fixed-wing radio-controlled aircrafts with smaller wingspans (1 m). In order to improve the performance of battery powered electric unmanned aerial vehicles (UAV), a model without PV cells (commercial Li-ion battery powered UAV) was compared with UAV powered both from battery and PV modules. This work shows details about Boost DC/DC converter and PV system design for small size fixed-wing electric UAVs, investigating the possibility of the application of PV powered drones, as well. Theoretical findings involving efficiency improvements have been confirmed by measurements combining the improvements in electrical engineering, microcontroller application and aerodynamics.

Lead-acid batteries are widely used in conventional cars. This electric energy storage system (ESS) has to be capable to store enough energy for cranking the conventional car after the weeks without additional charging. After the start of internal combustion engine (ICE) of conventional car synchronous machine usually called alternator start to generate electrical energy. Electric current supplied in this way should be rectified and stored in lead-acid battery for the next start-up. In this article a model of whole process was developed and simulated. Particularly, a supercapacitors were compared with lead-acid batteries and other battery types in sense of mass, reliability and other parameters. Results were confirmed by measurement on conventional car. Furthermore, possibility of replacement of lead-acid batteries with supercapacitors was analyzed.

Several blackouts have recently occurred in Europe and elsewhere. Blackouts are mostly the consequence of a series of events rather than a single event. Their intensity and frequency could be related to the stronger penetration of renewables into electric power systems. Although many different renewable power units may be installed, they all have some basic properties: their power is not consistent, and power inverters are used to connect renewables to electric power systems. Photovoltaic systems are the most typical representative of this large group of power sources. These devices have become more sophisticated over the past few years, allowing for the precise control of large photovoltaic fields. In this situation, all power converters act as one. This means that they could be turned on and off during short intervals. Furthermore, their power factor could be independently adjusted. These functions are desirable for small systems; however, their implications for stability at a larger scale are usually not considered. In this study, the stability issues of a system under the high penetration of renewables and a unique control system are investigated. The most prominent case of this influence is a high-impact rare (HR) event, also known as a “black swan”, which could cause a massive blackout in an electric power system.

Modern power inverters have additional functions compared to older generations of these devices. These additional functionalities provide more control over electric power systems; however, some drawbacks have recently been discovered. It has been taught that these power converter properties contributed to Iberian and other recent blackouts of unknown origin. This study aimed to investigate these drawbacks further and offer some ways to avoid these issues in electric power systems. These problems are more relevant in electric power systems with a higher penetration of renewables, especially photovoltaic systems. In this study, a comparison of several blackouts was made to determine the pattern of chain events in several cases. The same pattern was found in different countries where recent blackouts occurred, such as Turkey and Chile. These events are usually initiated at the high-power line as a consequence of manipulation or failure, causing the splitting of the electric power system into two parts, which are more vulnerable to sudden power surges introduced by grid-connected inverters, mainly photovoltaic power plants. Furthermore, simulations are offered to determine the reason for the sudden increase in power demand prior to the Iberian blackout. This simulation was performed for a limited number of elements to show the main effect, resulting in increased power demand and possible blackouts.