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Accuracy and reliability of the electric energy measurements have a high degree of importance. Automatic Meter Reading complex is a complex technical device, the failure of its any component can cause the error appearance up to the next metrological calibration procedure. Introduction of the mathematical algorithms for measurement data analysis in online mode will produce ongoing diagnosis of all...
This paper proposes modified dq control strategy that improves the dynamic response of the grid-connected inverter compared to the conventional approach. The idea is described and validated by means of simulation results. The transient time in traditional approach is 10 times slower than in the modified inverter with the same regulator parameters. The THD of the output current is almost the same.
Microgenerators are considered to become a substantial part of the decentralised power generation system in the near future. Biomass is widely used as heat source in the Nordics and wood-fired stoves serve as point heat sources for both homes and outdoor cabins. By using residual/waste heat from wood stoves the thermoelectric generator (TEG) based generation units can become an auxiliary source of...
Modem measurement systems being implemented in power systems worldwide provide the unprecedented possibilities of analyzing the electromechanical transients and especially the oscillatory processes. As the communication and data processing technologies are being advanced at a quick pace, the possibilities of detecting and characterizing the low-frequency oscillations, which may threaten the power...
Since the start of 2000th many methods which allow estimating the actual impact of imbalanced load into the voltage imbalance at the substation point of common coupling have been created. Most of these methods use measurement data for creating an equivalent electrical scheme which includes a foreign utility, a substation and a number of consumers. Using that scheme allows to estimate the impact of...
In medium voltage distribution network covered conductors are used to improve reliability and reduce interruptions and faults caused by snow, ice, storm and fallen trees; however covered conductors are more vulnerable than bare conductors against lightning caused burndown, therefore arc protection devices should be used. To study covered conductor overhead lines in case of direct lightning strike...
Generation adequacy indices (GAI) calculations are performed not only for electrical power system development problems but also for on-line control problems. Liberalization of power and energy market along with increased focus on renewable energy sources, which is motivated by both ecological and economical incentives, has led to comprehensive changes in power systems. Practically, the main mathematical...
In multiphase electric drives, the form of the phase current at which the best possible use of the “semiconductor converter-electric drive complex” for active materials is different from the sinusoidal form. The article proposes analytical methods for optimizing control actions applied to the inputs of a multiphase autonomous current inverter. An analytical method of searching for the optimum shape...
The paper presents analytical and experimental determination of the forced convection heat transfer coefficients over the flat side of a permanent magnet synchronous generator coil. In the analytical part, the forced convection coefficients at different wind speeds are calculated based on various known equations of the forced convection heat transfer coefficient with unhealed starting length. The...
Distinguishing with all the methods mitigating switched reluctance motors(SRMs)' vibration, this paper presents an effective damping method to weaken the vibration and noise propagation. Evaporative cooling stators can be considered as the damping method to the SRMs' vibration problem, as it reduces the radial electromagnetic forces in stators by immerging them into the evaporative cooling medium...
The objects of the research are the solar photovoltaic systems (PV) that generate a significant amount of the electrical consumption in the building. This paper describes the parameters that affect the payback period of photovoltaic systems. Analysis of the first year of use of specific photovoltaic system (Building of a warehouse in Pärnu) is presented. The paper contains a analysis of the actual...
This material is a general review of the current situation with hybrid vehicles in Russian Federation, based on the dynamics and economy of hybrid cars, and on their possible benefits and advantages in future.
The main trend to introducing controllable distributed generators, energy storages, modem switching equipment to the distribution grids of 0.4–35 kV and also development of energy metering systems is becoming more stable and aimed mainly at increasing the reliability of the consumer's power supply systems and partial increasing the efficiency of operating the energy exchange participants. The possibilities...
This paper provides in-depth analysis of the potential impact of demand-side management and energy efficiency improvements by evaluating energy consumption and efficiency according to the LVS EN ISO 50001:2012 standard at a glass-work company in Latvia. The electricity consumption monitoring system provides detailed data on energy consumption by the different types of production processes. In-depth...
This paper presents research results of industrial standard IEC 60870, presents design engineering data communications network using a standard for supervisor control system in electrical power engineering. The aim of the work is creation of realistic physical model multistaged network, quality level analysis this model and quality level analysis link protocol IEC 60870-5-104. Finally, article ends...
The article includes an empirical study of speed control possibilities for capacitor electric motors of a low power ventilator type load and motors with shaded poles using a phase voltage regulator. The results received were compared to the results of speed control obtained using the voltage variable with an autotransformer.
“Intelligent heating system” have widely established their position as a research field during the last decade. Nowadays the technical solutions related to energy resource management are being rapidly developed and integrated into the daily lives of people. The energy resource management systems use sensor networks for receiving and processing information during the realia time. Heating systems adaptive...
Brushless DC (BLDC) motors are increasingly replacing brushed DC motors due to their efficiency, long life smooth torque delivery and high speed operation. Usually, BLDC motors are commutated in six-step pattern with commutation controlled by position sensors. The implementation of sensorless control gives possibility to reduce cost and complexity of the motor control system. In the paper implementation...
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