George Seritan

Analysis of power quality improvement in smart grids

Electrical distribution system is designed to operate in sinusoidal mode, but the voltage and current waveforms shows distortion compared to the sinusoidal mode. Current technology development, which results in an increasing adoption of the local generation and storage capacities, is pushing towards the adoption of smart grid paradigm. An effective technical solution for enforce limitation of various types of power quality (PQ) disturbance is based on power electronics in order to increase energy transmission capacity, improve voltage stability and dynamic behavior, control power flow and ensure a better power quality at distribution inside accepted boundaries. The objectives of this paper is to assess the harmonic disturbances present into a real smart grid, and to suggest a solution to maintain the operation of the distribution system with photovoltaic (PV) plant and electrical cars within PQ limits imposed by standards. A general analysis was addressed, in order to identify the current state-of-the art of smart grid and harmonic filters and their influence on power quality. An example was designed using ETAP software, starting from a real electric distribution system in order to build a general image of corresponding PQ issues. The solutions found for this technical issues are presented with their influence on electrical current and voltage and harmonic specter.

Power quality assessment for microgrid scenarios

This paper deals with the rising issue of dealing with power quality issues, and aims at assessment of the impact of new smart technologies on existing electrical distribution systems from the reliability point of view. A main point in the analysis performed in this work is the characterization of the electric loads present in the upcoming micro-grids. The power quality assessment has then been performed by taking into account various generation and consumption characteristics, designed to cover the majority of cases. The paper addressed the impact of distributed generation on both distribution systems operation and energy management systems.

Optimization and monitoring energy consumption from small industrial consumers

Urgent need for energy savings involves introduction of intelligent monitoring and control networks for industrial consumers, including small and medium ones. New functions of smart grid and energy storage quality monitoring systems make up the path for new consumption ways. This paper presents a system solution that optimizes electricity consumption from small industrial customers through local control and also introducing renewable energies in the presented solution.

Analysis of the grid-connected PV plants behavior with FACTS influence

Within the EU Directive 20-20-20, which imposed a decisive action towards renewable energy adoption within electric power systems, this change brought a series of issues for the electric power systems, like losses increase, reliability alteration and power quality depreciation. The power generation of grid-connected PV plants is increasing continuously all over the world reaching values of hundreds of megawatts, thus making these plants a crucial part of the future electric energy system and Smart Grids. FACTS devices can be used to increase transmission capacity, improving stability and dynamic behavior, and ensure a better quality of energy by controlling several parameters. Current paper deals with the issue of power quality alteration, by assessing the influence which FACTS devices might have on the grid-connected PV plants both on normal and restricted conditions operation. In the first section, a general analysis was performed, aimed at identifying the current state-of-the art of FACTS technologies and their influence on power quality. An example was designed, starting from a real electric distribution system, in order to create an array of possible issues and solutions which will be further scrutinized.

Aspects of metrological calibration of power quality analyzers

This paper presents some aspects of power analyzers utilization, related with your calibration by metrological laboratory. The full metrological characterization of power analyzers is a difficult technical process because the specifications in related standard are minimal. After a short presentation of parameters and measurement methods recommended by the important standards in the field of power quality, CEI EN 50160 and CEI EN 61000-4030, study of uncertainty propagation related to test calibration, this document describes the instruments configuration and evaluation of measurement errors and uncertainties for one parameter, voltage in sinusoidal and non-sinusoidal regime.

Analysis of electromagnetic disturbances for grid-connected PV plants

The expansion of the electricity grid connected photovoltaic sources requires the development of solutions for solving problems caused by disturbances in the electrical network due to their strong variable character of energy sources. The power generation of grid-connected photovoltaic plants is increasing all over the world and these plants a crucial part of the future electric energy system. To restrict the level of electromagnetic disturbance, currently effective technical solutions are based on power electronics. This paper deals with the issue of power quality alteration, by assessing the power electronics equipment operation mode on the grid-connected PV plants both on normal and restricted conditions operation. A general analysis was performed in the first section, to identifying the current state-of-the art of photovoltaic plants and their influence on power quality and an example was designed, starting from a real electric distribution system in order to create a general image of issues and solutions.

Analysis of SVC influence on the power quality for grid-connected PV plants

The smart grid paradigm for the electric power systems is encompassing an increasingly adoption of distributed generation all over the world. This trend requires the input from flexible alternative current transmission systems (FACTS) devices, which can be used to increase transmission capacity, improving stability and dynamic behavior, and ensure a better quality of energy by controlling several parameters. Current paper deals with the issue of power quality influence, by assessing the static VAR compensator (SVC) operation mode on the grid-connected PV plants in order to assess the power quality limitations imposed by PV plants operation on sensible loads. In the first section, a general analysis was performed, aimed at identifying the current state-of-the art of FACTS technologies and their influence on power quality. An example was designed, starting from a real electric distribution system to which a generic SVC device was added, in order to create a general image of issues and solutions.

Use of pedagogical agents to build multiple choice equations for an electric workshop based on LabVIEW

e-Learning, with its various aspects, represents a major trend in education. This paper presents a solution to extend the traditional multiple choice tests to effectively graphic design of calculus equations for an electric workshop. Equation built procedure was augmented using animated pedagogical agents to increase the effectiveness of learning and practical skills and improve the attractive aspect of the process. The implemented algorithms and software were tested on two groups of bachelor degree students from Electrical Engineering Faculty, proving useful results and ways to develop further works.

Microgrids operation improvement using storage technologies

The advancements in technology and services are fundamentally transforming the traditional electrical power system operation. It is undergoing a full changeover into a collection of microgrids, which contains consumers that become prosumers. Energy storage is a vital component of the microgrids competitive operation. In this framework, current paper is addressing the issues of batteries capacity, prices and reliability. In the first section, a general analysis was performed, aimed at accurately identifying the current state-of-the art of storage systems. An example was designed, starting from a real electric distribution system, in order to identify the optimal solution from an array of possible technical issues and solutions which will be further discussed.

Analysis of ancillary services within smart grid framework

As a result of the changes that occur in the electrical distribution networks, there is guidance tendency toward users, not only to power systems. This is a feature of the smart grid that will ensure safety operational and power quality, and also facilitates network connection of renewable source. Smart grid can intelligently integrate the behavior of all users connected to this network - electricity producers, users and prosumers, in order to ensure efficient delivery, sustainable, economically and with security conditions of electricity. The power balance and ancillary services provided by the storage systems in distribution network represent two aspects of one problem that must be treated properly, with in an appropriate manner, taking into account the parameters of typical distribution network. Current limits of energy storage force production to correspond to the energy used in any moment. Using storage systems is a necessity for the power system, considering the current tendency to grow of renewable sources penetration, the requirements for reliability and power quality improvement and also the implementation of smart grid. Storage systems have an important role in increasing the system efficiency and ensuring stable operation of the system by contributing to secondary and fast tertiary control. In the first section, a general analysis was performed, in order to identify the current state-of-art of energy storage systems. An example was designed, starting from a real electric distribution system, in order to create an arrangement of possible issues and solutions for electricity storage systems which provide ancillary services.