Wyniki 1-4 spośród 4 dla zapytania: authorDesc:"Wojciech MATELSKI"

IM drive system supplied from PV panels with energy storage - experimental setup DOI:10.15199/48.2018.02.42

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184 PRZEGLĄD ELEKTROTECHNICZNY, ISSN 0033-2097, R. 94 NR 2/2018 have been conducted and the results in form of selected waveforms are presented. Solar powered drive with energy storage The presented in this article drive system consists of an induction motor, powered from a solar panel array. The general concept of the system, in form of a block diagram, is depicted in Figure 1. Considering the moderate irradiation conditions in Poland, the solution incorporating an energy storage device has been adopted. The system can be used in applications characterized by intermittent operation, like water pumps for field irrigation or elevator systems. Fig.1. IM drive system supplied from PV panels block diagram For energy storage purposes supercapacitors SC were chosen. Even if their energy density is not comparable to that of conventional electrochemical accumulators, like the commonly used lead-acid batteries, their high power density, large number of charge and discharge cycles (approximately 1 million), shorter charging times and the possible amount of stored energy, makes them compatible with many industrial applications [13], like for example elevator systems [9 - 13]. What is more, lead-acid battery banks are heavy and expensive and their lifetime is estimated to be one fifth of the lifetime of a solar panel [5]. As can be seen from Figure 1, the system does include an optional industrial low voltage three phase grid connection. In this way, the system becomes a more reliable power source, so the operation of the load can be ensured for example in emergency situations. In cases of poor weather conditions, energy can be drawn from the grid in order, if necessary, to fed the load, or it can be stored in the SC, when the prices are low, for example at night. The power flow is controlled by the means of power electronic converters, and in the block scheme from Figure 1, they are contained in the block denoted as PES. This stru[...]

Hybrid stepless distribution transformer with four-quadrant AC/DC/AC converter at low voltage side - simulation tests DOI:10.15199/48.2018.06.23

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The present energy distribution grid is in operation for decades and works with the same principles since its establishment [1]. This grid was designed to supply linear loads, i.e. light bulbs or heaters. For such devices the power drawn from the grid decreases together with the voltage, mitigating the negative effects of lowering the voltage. In recent years the operating conditions of the distribution grid have changed. Most of modern loads work with constant power demand. In such cases the decrease of the voltage causes an increase of the current drawn, which intensifies the problems occurring in the distribution systems. The change of grid operation conditions is also the effect of the work of distributed generation systems, with a large contribution of renewable energy sources (RES). The increasing number of dynamic loads, i.e. fast charging stations for electric vehicles (EV) are also a reason of this issue. As a result, increasing voltage fluctuations in the grid become more severe. In order to control the voltage level, conventional distribution transformers (DT) are complemented by various Automatic Voltage Regulator (AVR) devices, starting from electromechanical servomechanisms, through transformer tap changers (TC), to Solid State Transformers (SST) [1-4]. Currently, despite such disadvantages like arcing, high operation costs or poor dynamics, mechanical tap changers are the most common solution. However this AVR technology does not keep up with the present grid voltage regulation requirements, especially in terms of dynamics and accuracy, anymore. This is the fundamental reason behind the growth in the application of power electronic based AVR devices. Thyristor tap changers (DT+TC) [4-6], although operating on a similar principle as their mechanical versions, they eliminate arc problems and guarantee higher dynamics of regulation. These switches, however, still operate in a step manner, and the indicated de[...]

Selection of AHI + SC Hybrid Storage Based on Mathematical Models and Load Variation Characteristics DOI:10.15199/48.2018.05.21

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With the increasing use of renewable energy sources, such as photovoltaic panels and wind turbines, there is growing interest in new ways of collecting and storing electricity. Typical solutions in this area are lithium-ion or lead-acid batteries. The main shortcomings of these examples are: limited durability, toxicity of appropriate electrolytes and components, potential fire hazard, disposal problems of waste batteries. The new high quality component that has appeared on the market is a battery called Aqueous Hybrid Ion battery containing salt electrolyte - neutral to the environment. For a detailed description of AHI battery technology, see [1]. The materials used in the construction do not contain heavy metals and are fully recyclable as opposed to existing leadacid, nickel-cadmium, nickel-metal hydride, sodium-sulfur, and lithium-ion batteries [2]. This component also does not present a fire hazard. In addition, the AHI battery ensures significant durability expressed by a large number of charging and discharging cycles. Due to the aforementioned advantages it is suitable for the construction of scalable storage, in particular for stationary applications. However, the disadvantage of this type of battery is the relatively large internal resistance, which complicates the assembly of a structure suited for large, pulsed charging and discharging currents. In such cases the solution may be to use an additional component in the form of a supercapacitor. This problem is the subject of many studies [3], [4], [5], [7], which point out the possibility of improving the dynamic parameters and extending the battery life. The following sections show how to create the AHI battery model and the supercapacitor model as components of the hybrid system. An example hybrid storage system, made up of AHI type S30-0080 batteries and LSUM 129R6C 0062F EA supercapacitor, was established and used for the validation of the elaborated model. [...]

Supercapacitors based driving system for space fast surface sample acquisition system DOI:10.15199/48.2018.05.27

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Space missions aimed at providing ground samples taken on other bodies to Earth are one of the ways to extend our knowledge of extraterrestrial materials and processes occuring on and under their surface. So far, several missions have been carried out to retrieve and transpose samples such as Apollo, Hayabusa or Phobos Ground. The European Space Association (ESA) is currently planning next missions, such as Phootprint, MarcoPolo-R, Hayabusa-2, OSIRIS-Rex or NASA is preparing Resource Prospector mission to the Moon. The mission called Phootprint is proposed to be launched with an Ariane 5 on 2024 with early 2026 as backup date. Ariane 5 is a heavy launch rocket used to deliver payload into geostationary orbit. One of the top-level science goals is to understand the formation of the Martian moons Phobos (20x26 km) and Deimos (12x16 km) (fig.2) and put constraints on the evolution of the Solar System (fig.1). The mission would last about 3,5 years, including cruise, orbit mapping, 7 days on the surface, and sample return cruise time. The spacecraft would be powered by solar arrays. Because of the low gravity, the lander would be anchored to the surface during sample collection and launch back of the Earth Re-entry Capsule (ERC).A part of Phootprint mission/lander is the project aimed to ground sampling device, named PACKMOON.There are three main aspects related to the investigation of new types of sampling tool solutions: - High-amplitude dynamic force is the most effective way to pump energy into the end of crack. - For safety reasons, the sampling tool must not anchor the lander. It means that the geometrical topology and associated device movement must be reversible. - The sampling tool must not disturb the sample interior structure. Furthermore, the sample must be easily secured and released if needed. Fig.3. Phootprint mission lander [3] The device called PACKMOON presented in figure 4, is a mechatronic system, that eff[...]

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