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1 Introduction to Power Quality
Published in C. Sankaran, Power Quality, 2017
Power quality is a term that means different things to different people. Institute of Electrical and Electronic Engineers (IEEE) Standard IEEE1100 defines power quality as “the concept of powering and grounding sensitive electronic equipment in a manner suitable for the equipment.” As appropriate as this description might seem, the limitation of power quality to “sensitive electronic equipment” might be subject to disagreement. Electrical equipment susceptible to power quality or more appropriately to lack of power quality would fall within a seemingly boundless domain. All electrical devices are prone to failure or malfunction when exposed to one or more power quality problems. The electrical device might be an electric motor, a transformer, a generator, a computer, a printer, communication equipment, or a household appliance. All of these devices and others react adversely to power quality issues, depending on the severity of problems.
Fundamental Electronics
Published in Patrick F. Dunn, Michael P. Davis, Measurement and Data Analysis for Engineering and Science, 2017
Patrick F. Dunn, Michael P. Davis
Current is a measure of the flow of electrons, where the charge of one electron is 1.602 177 33 × 10−19 C. Materials that have many free electrons are called conductors (previously known as non-electrics because they easily would lose their charge [1]). Those with no free electrons are known as insulators or dielectrics (previously known as electrics because they could remain charged [1]). In between these two extremes lie the semi-conductors, which have only a few free electrons. In the early 1800s, it was assumed that current was the flow of positive charge. This was referred to as conventional current. Since then, it has been established that current is the flow of negative charge (electrons) in the direction opposite to that of conventional current. This is referred to as electron flow. Typically, electrons flow from the anode of an electrical device through a circuit to the cathode. However, the polarities of the anode and cathode depend upon the type of electrical device. For example, the anode’s polarity on a discharging battery is negative (electrons move out from the anode), whereas it is positive for a recharging battery (electrons move into the anode). Direct current (DC) is constant in time and alternating current (AC) varies cyclically in time, as depicted in Figure 5.1. When current is alternating, the electrons do not flow in one direction through a circuit, but rather back and forth in both directions. The symbol for a current source is given in Figure 5.2.
Electric Energy Systems
Published in Antonio Gómez-Expósito, Antonio J. Conejo, Claudio A. Cañizares, Electric Energy Systems, 2018
Ignacio J. Pérez-Arriaga, Hugh Rudnick, Michel Rivier Abbad
Electric power consumption may be very sensitive to the technical properties of the supply of electricity. Many devices malfunction or simply do not operate at all, unless the voltage wave is perfectly sinusoidal and its frequency and magnitude are constant and stable over time. The precision, quality, features, and performance of electrical devices depend on the quality of the current that powers them. Problems may also arise in almost any type of electrical device when the supply voltage is too low or too high (overvoltage). Computer, motor, and household appliance performance may suffer or these devices may even fail altogether when the supply voltage swings up or down. Most electrically powered equipment, especially a particularly expensive equipment or any equipment regarded to be vital for the proper and safe operation of all kinds of processes, is fitted with protection systems—fuses, circuit breakers and switches, protection relays—to prevent damage caused by voltage fluctuations outside an acceptable range. Thus, for instance, the motors that drive the cooling pumps in nuclear power plants are fitted with under and overvoltage protection that may even trip systems that cause plant shutdown, given the vital role of these motors in safe plant operation. Finally, outages, whether short or long, are clearly detrimental to service quality. For example, unstored information representing hours of work on a PC may be lost because of an untimely power outage. But power failures can cause even greater harm in industries such as foundries or in chemical or mechanical processes whose interruption may entail huge losses.
An extensive critique on fault-tolerant systems and diagnostic techniques intended for solar photovoltaic power generation
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Albert Alexander Stonier, R. Harish, M. Srinivasan, D. Sarathkumar
In the research that applied fault-tolerant designs and topologies, the objective was to identify the physical solution that would either isolate the problem or lessen the damage it possibly brings. With the development in solar power generation in the form of smart grid, micro-grid, and grid-tie-based, this analysis discusses the faults in the entire solar power generation unit consisting photovoltaic arrays, charge controller, DC to DC converter, battery, and inverter. Here the study deals with solar photovoltaic cells consisting of solar cells, otherwise called photovoltaic cells. A photovoltaic cell is an electrical device that converts light energy to electrical energy through the photovoltaic effect, which consists of physical and chemical phenomena. PV cell is a transducer that converts the sunlight energy to an electrical form of energy through silicon-based semiconductors with a voltage capability of 0.5 V to 1 V and a current value of 20 mA to 40 mA depending on the materials and sunlight condition. The efficiency of the solar cell is 15%, but as the solar energy is free of cost does not impact on efficiency. The maintenance and cost of the solar cell is a major problem (INR.1400 to INR.7000 per watt). This technology may compete with conventional electrical power generation methods, particularly as a conventional source of energy.
Experimental investigations of effect of depth of Swiss roll combustor on its thermal performance as a heat generator
Published in International Journal of Ambient Energy, 2019
Sagar B. Mane Deshmukh, A. Krishnamoorthy, Virendra K. Bhojwani
Combustion in the small-scale combustors has explored with the advent of use of hydrocarbon fuels (gases or liquids) which have more energy density (i.e. may be 100 folds more than the commercially available lithium-ion batteries) (Fernandez-Pello 2002). Heat energy generated by burning the hydrocarbon fuels can be converted into an electrical energy through the thermal electrical device or photovoltaic device (Jejurkar and Mishra 2009). Electrical energy generated can be used in various applications such as personal digital assistants, cellular phones, unmanned aerial vehicles and small space heating. Small-scale mechanical systems which use energy produced by small-scale combustion inside the small-scale combustors can be developed successfully with the following major advantages: (1) low weight, (2) small size and (3) long life. But the key issue at the small scale of the combustor is the higher surface to volume ratio of the combustor, which increases heat loss to surrounding, which would lead to failure of combustion (stage of losing the flame stability) called as flame extinction/flame quenching. To get a stable flame in the small combustor, heat recirculating combustor (also called as excess enthalpy combustor) was proposed by Lloyd and Weinberg (1974, 1975). Proper thermal management system increases chances of using heat recirculating combustors along with thermal electrical, Piezo-electric and Pyro-electric devices (which have no moving parts) to generate electrical energy and can give better overall efficiency. Flame stability and flame propagation are the main issues faced in small-scale combustors.
Power Electronic Converter Configurations Integration with Hybrid Energy Sources – A Comprehensive Review for State-of the-Art in Research
Published in Electric Power Components and Systems, 2019
Kumar Krishnamurthy, Sanjeevikumar Padmanaban, Frede Blaabjerg, Ramesh Babu Neelakandan, Kettavarampalayam Ramanathan Prabhu
Governments, industry, and researchers exhibit lot of interest in this solar energy, due to its free availability in nature and its zero discharge of greenhouse gas. The amount of solar radiation energy conversion into electrical energy depends upon the efficiency of PV cell and PV module. PV cell is an electrical device which converts solar energy directly into the electrical energy. It contains p-n junction formed by the semiconductor materials. When solar light falls on the p-n junction PV cell, it produces current by the photovoltaic effect. The numbers of solar cells are connected in series and parallel to form a PV module to generate the required amount of current and voltage [14].