Power Quality and Resonances in Power Supply Systems with Non-Sinusoidal Loads

2017 ◽  
Vol 25 ◽  
pp. 143-150
Author(s):  
Yurii Papaika ◽  
Oleksandra Lysenko ◽  
Grzegorz Kosobudzki

The stress is made on the necessity to take into account the impact of higher while analysing the quality of voltage in power supply systems of coal mine. The process of resonances in power supply systems is explained in terms of physics, the sources generating this kind of interference are described. Mathematical dependences that allow to identify resonances in power supply systems are provided. The focus is placed on the feasibility of using spectral analysis in computations. To investigate the understudied aspects of voltage quality and electromagnetic compatibility and provide mathematical description for the analysis of resonances in electrical networks with powerful non-sinusoidal loads.

2021 ◽  
Vol 247 ◽  
pp. 132-140
Author(s):  
Yurii Sychev ◽  
Roman Zimin

The urgency and necessity of choosing and justifying the structures of hybrid filter-compensating devices based on series and parallel active filters to improve the quality of electricity in the power supply systems of enterprises of the mineral resource complex is shown. Mathematical models of hybrid filter compensating devices based on parallel and series active filters have been developed. Based on these mathematical models, computer simulation models of the indicated hybrid structures have been developed. The results of simulation showed the effectiveness of the correction of power quality indicators in terms of reducing the level of higher harmonics of current and voltage, as well as voltage deviations. The degree of influence of filter-compensating devices on the power quality indicators, which determine the continuity and stability of the technological process at the enterprises of the mineral resource complex, have been revealed. It has been established that a hybrid filter-compensating device based on a parallel active filter can reduce the level of higher harmonics of current and voltage by more than 90 and 70 %, respectively, and based on a series active filter, it can reduce the level of higher harmonics of voltage by more than 80 %. Based on the simulation results, the possibility of compensating for the reactive power of a hybrid structure based on parallel active and passive filters has been revealed. The possibility of integrating hybrid filter-compensating devices into more complex multifunctional electrical systems for the automated improvement of the quality of electricity is substantiated, as well as the expediency and prospects of their use in combined power supply systems based on the parallel operation of centralized and autonomous sources of distributed generation.


2019 ◽  
pp. 58-65
Author(s):  
Yryskeldi Kargabaev ◽  
Kubat Osmonaliev

The article deals with the tasks of ensuring the required quality of electricity in modern power systems of industrial enterprises. The main tasks of designing and operating modern power supply systems for industrial enterprises are in addition to the rational choice of elements of power supply systems, it is also to ensure the required quality of electricity at the terminals of the power receivers. Ensuring the required quality of electricity is generally associated with the electromagnetic compatibility of the supplynetwork. The intensification of production processes is associated with the improvement of technological processes and the introduction of advanced technologies, with the use of high-performance equipment, in particular, valve converters, welding plants, powerful metalworking machines are being introduced. They are currently controlled using digital technology, these devices strictly impose high demands on the quality of electrical energy.In connection with the requirements of the quality of electricity, in the Russian Federation every 10-15 years new standards are developed, where the indicators of the quality of electric energy are normalized


2019 ◽  
Vol 14 (3) ◽  
pp. 96-102
Author(s):  
Александр Виноградов ◽  
Aleksandr Vinogradov ◽  
Алина Виноградова ◽  
Alina Vinogradova

Interpretation of the efficiency of power supply systems is proposed, according to which the main criterion of efficiency is minimization of costs for the operation of the power supply system under certain conditions related to the reliability of power supply, power quality and timing of technological connections. The methodological approach to improving the efficiency of power supply systems for rural consumers requires the development of efficiency criteria that would allow all measures to improve the reliability of electricity supply, power quality, shorten time and improve the quality of technological connections to lead to uniform indicators by which to evaluate the effectiveness of these measures. The costs arising from the operation of power supply systems can be divided into stimulating and providing. Both of these components, in turn, are also divided, while the stimulating costs include those components of costs that stimulate electricity supply companies to comply with the requirements of reliability of power supply, power quality, quality of services of technical connections. Regulation of incentive costs, which include damages from interruptions in power supply, compensation costs, lost profits, etc. allows you to manage the efficiency of power supply systems. Providing costs include investment and operating costs, since these types of costs provide the ability to fulfill the conditions of quality of services provided by electricity supply companies. All components of the costs associated with the values ​​of the time of interruptions in the power supply, the time of the mismatch of the quality of electricity and the time of the technical connections. The dependencies of component costs on the time of interruptions in power supply are shown. These dependencies can be interpreted in the opposite version, as time dependencies on costs. This reading allows them to develop incentive mechanisms for energy companies and consumers to improve the reliability of power supply, power quality and quality of connection services.


2014 ◽  
Vol 529 ◽  
pp. 501-505
Author(s):  
Chi Zhang ◽  
Ming Zhi He

With the continuous development of power electronic technology, the advantages of thyristor power regulator circuit gradually get more and more applications. It improves the quality of power supply, makes the equipment efficiency and power factor higher and so saves a lot of electricity. Through the calculation of the primary current when thyristor turns off in three-phase power regulator circuit with transformer load, the impact of the thyristors turn-off order on the transformer primary current voltage-second product is analysised, and through simulation the exactness is verified.


2020 ◽  
Vol 23 (2) ◽  
pp. 52-58
Author(s):  
S. SKRYPNYK ◽  

Our world with its high technologies has long been deeply dependent on the quality of electricity supply. In most countries of the world there are national power grids that combine the entire set of generating capacity and loads. This network provides the operation of household appliances, lighting, heating, refrigeration, air conditioning and transport, as well as the functioning of the state apparatus, industry, finance, trade, health services and utilities across the country. Without this utility, namely electricity, the modern world simply could not live at its current pace. Sophisticated technological improvements are firmly rooted in our lives and workplaces, and with the advent of e-commerce began the process of continuous transformation of the way individuals interact with the rest of the world. But with the achievement of intelligent technologies, an uninterrupted power supply is required, the parameters of which exactly meet the established standards. These standards maintain our energy security and create a reliable power system, that is maintaining the system in a trouble-free state. Overvoltage is the deviation of the rated voltage from the value of the corresponding quality standard (frequency, sinusoidal voltage and compliance of harmonics). Overvoltage in terms of fire hazard is one of the most dangerous emergency modes of electrical equipment, which causes conditions that in most cases are sufficient for the occurrence of fire hazards (exceeding the allowable voltage leads to disruption of normal operation or possible ignition). Against the background of deteriorating engineering systems, increased power consumption and poor maintenance, power supply of electrical installations, the main causes of overvoltage in electrical networks are thunderstorms (atmospheric overvoltage), switching switches, uneven phase load in electrical networks, etc. The physical picture of internal overvoltage is due to oscillatory transients from the initial to the established voltage distributions in the conductive sections due to the different situation in the electrical circuit. In the conditions of operation of electric networks planned, mode or emergency situations are possible. Therefore, the ranges of overvoltage are determined by the range from several hundred volts to tens and hundreds of kilovolts, and depend on the types of overvoltage. Atmospheric overvoltage is considered to be one of the most dangerous types of emergency modes of operation of the electrical network. This overvoltage occurs as a result of lightning discharge during precipitation by concentrating electricity on the surface of the object, the introduction of potential through engineering networks and


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