September 29th

Overvoltages due to Wind Power - Hosting Capacity, Deterministic and Statistical Approaches

This paper introduces methods to quantify the impact of wind power and other types of distributed generation on the overvoltage risk. The so-called hosting capacity approach, introduced in the very first issue of this magazine, is used as the basic approach. Both a deterministic and a statistical approach are introduced. The deterministic approach is suitable for generation with a constant production most of the time. However, it is shown that a deterministic approach could easily result in an unnecessary barrier against the introduction of wind power. For any method used to determine the hosting capacity, a serious discussion is needed about overvoltage indices and objectives.

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September 26th

A view on Nuclear Energy

The following article is the result of an interview with Jean Van Vyve and provides a brief overview of the significance of and prospects for nuclear energy in the energy sector. The article is published as an eBook so you can scroll the different pages using the titles below. The full article is also available as a PDF for download.

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September 25th

Inductive Decoupling of Low-Voltage Sub-Networks

Voltage control in networks with predominantly resistive coupling is most efficient when controlling the active power flow. By introducing a series connected inductor for a dedicated part of the network the coupling can be shifted to the inductive type. Hence the voltage in such sub-networks can be influenced by injection of reactive power. Furthermore harmonic distortions present in the main grid are reduced.

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Distributed Generation Impact on Voltage Sags in Distribution Networks

Characteristics of voltage sags caused by faults in distribution networks depend on the design of the protection system and the coordination between the different protective devices. The presence of distributed generation (DG) changes the radial nature of distribution systems, so it can affect the performance of the protection system, and consequently the characteristics of voltage sags. In addition, DG will help to maintain the during-fault voltages of healthy phases.

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IEC 61850 as a flexible tool for electrical systems monitoring

In the last decades there have been great advances in electronic, information and communication technologies. Up to date, any of these advances have been implemented in electrical systems, but some difficulties have been encountered, particularly regarding to the integration of intelligent electronic devices from different manufactures into a centralized system. With the aim of solving the above mentioned problem, the standard IEC 61850 was developed to specify communication networks in substations.

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Laboratory of Distributed Generation in Institute of Electrical Power Engineering of Technical University of Lodz

In the paper major laboratory equipment is described: photovoltaics, microturbine, fuel cell, battery energy storage, together with the configuration of the laboratory network facilitating studies of characteristics of those energy sources and problems of cooperation of distributed generators with electrical power network. For integration of distributed sources into the power system it is necessary to properly control their operation.

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September 22nd

Eco-sheet: 1 kWh generated using different energy sources

How sustainable is a kWh?

What is the best technology to produce it?

 

These questions are often asked and the answers are not clear-cut, as there are a lot of variables.

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Design and Testing of a Low Cost Peak-Power Tracking Controller for a Fixed Blade 1.2 kVA Wind Turbine

Wind turbines are a common source of electrical power generation in rural sites around the world. The power generated by a wind turbine at a given wind speed is a non-linear function of rotor speed. This results in a specific rotor speed for maximum power production at each wind speed. A control system incorporating a Pulse Width Modulated DC -DC converter has been designed to vary the load on the wind turbine thereby forcing it to operate at its maximum power point.

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Electromagnetic Coupling of the Electrical Drive - EMC (Part II)

The paper deals with the general analysis of one part of the electromagnetic compatibility (EMC ) problem — the electromagnetic coupling applied in the field of power electrical systems as. The simulation analyses and practical measurements of the electromagnetic coupling are presented in part II . Obtained results confirm the correctness of the theoretical analyses and so they can be used for predictive stating of EMC quality of individual new electrotechnical products.

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Diagnostics of Commutator DC Motor Basing on Spectral Analysis of Signals

Measurement investigations have been carried out for commutator dc motor with internal asymmetries. Construction of considered motor enables to realize the breaking of one rotor coil and shorting of two groups of rotor coils. Each group contains three rotor coils. The basis of study were signals: current and voltage of field winding, current and voltage of armature winding and velocity of the rotor.

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