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The report reviews practice of solving power quality problems, mainly in the part of establishing power quality monitoring systems; it also contains feasibility analysis for establishing similar systems in Russian Federation and, additionally, provides information about a Russian-made regional power quality monitoring system based on PRORYV- KE devices.
This paper aims at analyzing some important aspects related to ideal and nonideal electrical systems. In this way, the analyses are presented in the theoretical form, followed by typical examples from field measurements. It is usual to associate some harmonic orders with specific equipment operation, like a noncontrolled 6 pulse rectifier, a motor, a generator, etc. These structures define characteristic...
The quality of the electrical supply is a critical issue in a Synchrotron Light Source Facility. The facility will comprise a 3 GeV electron storage ring - fed from a 100 MeV linac and a full energy booster synchrotron - that will generate synchrotron radiation into, initially, seven beamlines. A description of the electrical supply system requirements and the solutions adopted will be presented in...
The improvement of the effectiveness and the life time of fuel cells requires the optimization of components such as membranes and electrodes and enhancement the flow of gases. To this end, the impedance measurement is essential. In this paper we present an electronic measurement instrumentation developed in our laboratory, to measure and plot the impedance of the fuel cell on load. Impedance measurements...
The PWM-supplied permanent magnet synchronous machines are exposed to magnets' heating due to harmonic fields which rotate in relation to rotor. The corresponding losses can be calculated by FE simulation for each frequency, with superposition of all components of the losses. In certain conditions three dimensional modelling is required to get enough precision. However, time-stepping 3D finite element...
A change in technology is taking place in power factor correction. Fast changing loads demand new, dynamic solutions that offer additional technical advantages and economic benefits. In this paper basic advice for the composition of a dynamic power factor correction (PFC) system is given. As example the setup and performance of a dynamic PFC system for wind turbines, named DynaWind 6000, is presented,...
Power quality is a compatibility problem; it can be solved either by making the power better, or by making the loads tougher. The latter approach is encouraged by power quality immunity standards, which are rapidly changing. SEMI F47 has just been updated; IEC 61000-4-34 is starting to take effect internationally and soon in Europe; and other standards are coming on line. This paper discusses the...
Necessity for power quality monitoring emerges from rules on deregulated market, legislation according to it, standardization and quality control of delivered merchandise (electrical energy) to the customer, as well as a control mechanism for customers' installations effect on public distribution networks. On today's market of power quality measuring devices there is a lot of quality hardware, but...
Transelectrica is the Romanian Transmission System Operator and the Meter Operator of the Wholesale Electricity Market (WEM). Some of its partners are Electrica and the eligible consumers. Maintaining the Power Quality (PQ) indices within admissible limits, in the common coupling points (CCPs), is one of the most important of the WEM actors. This paper addresses the salients results of the the first...
When planning the application of renewable energy sources it is necessary to take decisions not only on the basis of elementary information about these energy sources but also on the basis of more general and more profound knowledge than is currently available. Complex and additional information about the intended application can be obtained from measuring, collecting and analysing relevant data....
This paper is focused on problems of power quality in systems with varying frequency, equipped with passive harmonics filter. Main differences between the ship system and land network have been pointed out. Influence of varying frequency on proper work of harmonic passive filters frequency change was presented. Simulation circuit and simulations results of theoretical research have been described...
The paper describes importance of the reactive power control basing on the failures and control problems in the Polish transmission networks in summer 2006. A detailed description of the operational difficulties is provided. Conclusions, repairs and prevention undertaking are also described.
A low power factor and an increased harmonic content are some of the negative effects of the nonlinear loads and power electronics converters. In order to mitigate these effects, active power filters with complex current loops together with appropriate current control strategies are proposed. In this paper a new method to generate the reference current using a recursive algorithm is presented. Due...
Introduction of a tariff system which also considers the harmonic injection level is gaining importance as a mechanism to limit the increasing levels of harmonics in power systems. Many researchers have proposed methods to quantify the harmonic power flow from both supply side and load side so that penalties for harmonic injection can be introduced into the tariff structure. The IEEE Standard 1459-2000...
IEC 61000-4-30 is an excellent standard that ensures that all compliant power quality instruments, regardless of manufacturer, will produce the same results when connected to the same signal. However, instruments that comply with Class A requirements of this standard have, until now, been too expensive for common use. A new set of technologies developed by an American company, in cooperation with...
Transelectrica is the Romanian Transmission and System Operator (TSO). In the company's activities, the Power Quality aspects are very actual and important. First part of the paper contains the standards and technical requirements regarding the Power Quality aspects included in Romanian technical code of the Electricity Transmission Grid. The reference concerns only the high voltage grid. The second...
Comparing flicker planning levels and flicker requirements given by utility companies world wide, it can be found that there are great differences in these planning levels and thus in requirements to companies which have installed flicker generating equipment such as arc furnaces, welders etc. Taking into account that the flicker immunity of equipment, connected to LV systems and the flicker sensitivity...
Electric appliances consume electricity when they are in standby mode and sometimes even in off-mode. These "losses" of each appliance individually are not large but the sum over all appliances is no longer negligible. The standby losses of ten households are investigated. The standby power varies from 7 to 134 W and has an average of 40 W. The standby consumption is on average 274 kWh/year,...
In the paper a new scheme for power line voltage measurement is suggested. It uses coreless measurement transformer because it is precise, linear and assures galvanic separation of measuring instrument from high input voltage as well. Theoretical linearity is calculated and it is the most important property of the device. The amplitude and phase linearity limits are significantly lower then 16-bit...
Power quality measurement is still a quite embryonic market although there are hundreds of manufacturers around the world. Whereas basic variables like RMS values of voltage and current are well defined, some power quality variables are not. This has led to a situation, that different instruments might show different results. The standard, issued by the International Electrotechnical Commission, IEC...
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