Earth fault detection in distributed power systems on the basis of artificial neural networks approach

Nowadays, the advancement of microgrids promises numerous economic and environmental advantages of renewable energies to nations and societies. The presence of decentralized energy units, however, makes serious technical challenges; for instance, criteria and procedure of fault recognition and diagnosis in this condition is entirely changing. This article, therefore, proposed a novel accurate and fast technique based on Artificial Neural Networks (ANN) for earth fault detection. A sample distributed power system considered for the proposed technique and different earth faults applied to this system consist of one phase, two phases and three phases faults. Also, any alteration of current and voltage signals of all phases is investigated at the fault occurrence moment. Analysis of simulation results demonstrates how the proposed technique could make faster responses and improve the reliability of the distributed power system by more accurate fault recognition in comparison with the other traditional methods such as the Wavelet Transformation technique. The proposed technique is likely to enhance the growth of renewable energy sources usage by decreasing operational risk factors and fault recognition delays.

Review on Active Islanding Detection Technique in Distributed Generation for Current Controlled Inverter

The Goal Islanding occurs when a portion of distributed power system becomes electrically isolated from the rest of the power system yet continues to be energized by distributed generators. All such occurrences are needed to be detected as early as possible in order to safely shut down the distributed generators. This is because, continued operation of these generators under islanding can lead to multitude of operational hazards/challenges to the generators and to connected loads.The current industry practice is to disconnect all distributed generators immediately after the occurrence of islands. Typically, a distributed generator should be disconnected within 100 to 300 ms after loss of main supply. To achieve such a goal, each distributed generator must be equipped with an islanding detection device, which is also called anti islanding devices. In this study, an active islanding detection technique is proposed for grid connected inverters. Feasibility of the proposed technique. Proposed project run on MATLAB 2016 Simulink environment.

Active Synchronous Control Strategy of Distributed Power Grid Connection Based on Mobile Network

This paper presents an active synchronous control scheme for distributed power grid connection based on the mobile network. This scheme avoids the disadvantages of the traditional control method, such as long waiting time and low reliability, and can meet the requirements of “the hotplug online” distributed power grid connection. The scheme uses the mobile network to collect and detect voltage slip information between the distributed power system and large power grid before operation. When the voltage slip cannot meet the requirements of grid connection, the side voltage information of the distributed power system is actively regulated. The amplitude difference and phase difference signals are, respectively, adjusted by PI, and the generated adjustment signals are, respectively, sent to the corresponding controllers through the mobile network with different weight coefficients. After the receiver receives the regulated signal, it changes the amplitude and frequency of its output voltage by shifting the pendent characteristic curve, so as to realize the distributed power system side voltage and the large power grid side voltage eventually. Finally, simulation analysis and experiments are used to verify the effectiveness and practicability of the active synchronous control strategy.