scholarly journals Instantaneous Disturbance Index for Power Distribution Networks

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1348
Author(s):  
María Dolores Borrás-Talavera ◽  
Juan Carlos Bravo ◽  
César Álvarez-Arroyo

The stability of power systems is very sensitive to voltage or current variations caused by the discontinuous supply of renewable power feeders. Moreover, the impact of these anomalies varies depending on the sensitivity/resilience of customer and transmission system equipment to those deviations. From any of these points of view, an instantaneous characterization of power quality (PQ) aspects becomes an important task. For this purpose, a wavelet-based power quality indices (PQIs) are introduced in this paper. An instantaneous disturbance index (ITD(t)) and a Global Disturbance Ratio index (GDR) are defined to integrally reflect the PQ level in Power Distribution Networks (PDN) under steady-state and/or transient conditions. With only these two indices it is possible to quantify the effects of non-stationary disturbances with high resolution and precision. These PQIs offer an advantage over other similar because of the suitable choice of mother wavelet function that permits to minimize leakage errors between wavelet levels. The wavelet-based algorithms which give rise to these PQIs can be implemented in smart sensors and used for monitoring purposes in PDN. The applicability of the proposed indices is validated by using a real-time experimental platform. In this emulated power system, signals are generated and real-time data are analyzed by a specifically designed software. The effectiveness of this method of detection and identification of disturbances has been proven by comparing the proposed PQIs with classical indices. The results confirm that the proposed method efficiently extracts the characteristics of each component from the multi-event test signals and thus clearly indicates the combined effect of these events through an accurate estimation of the PQIs.

Author(s):  
Mahmoud Zadehbagheri ◽  
Rahim Ildarabadi ◽  
Majid Baghaei Nejad ◽  
Tole Sutikno

<p>Power distribution networks are considered the main link between power industry and consumers and they are exposed to public judgment and evaluation more than any other section. Thus, it is essential to study power quality in distribution section. On the other hand, power distribution networks have always been exposed to traditional factors such as  voltage sag, voltage swell, harmonics and capacitor switching which destruct sinusoidal waveforms and decrease power quality as well as network reliability. One of the methods by which power quality problems might be addressed is to apply power electronic devices in the form of custom power devices. One of such devices is Dynamic Voltage Restorer (DVR) which is connected in series to distribution networks. At the same time, through injection of voltage to the network it is able to control voltage amplitude and phase. It is  adopted lend to compensate for voltage sags through injecting series and synchronous three phase voltage. This paper reviews on the application of DVR for Voltage Compensation in recent years and gives sets of information for each control of the DVR in distribution networks.</p>


Author(s):  
Fillipe Matos de Vasconcelos ◽  
Celso Henrique Santos Rocha ◽  
Carlos Frederico Meschini Almeida ◽  
Danilo de Souza Pereira ◽  
Luiz Henrique Leite Rosa ◽  
...  

Author(s):  
Amarjeet Singh ◽  
Shivangee Shukla

The Wind generation system has potential application for the grid support that could be utilized in rural areas. However, continuous variation of wind speed results in severe power quality problems, especially in a standalone village network. In distributed generation, wind power system can cause sub harmonic and interharmonic components to appear in the spectrum of voltage and currents. These harmonics can cause flicker, overload, and interference, on the electronic equipments. This paper proposes Dynamic Voltage Restorer (DVR), which is the most efficient and effective modern custom power device used in power distribution networks. This could be used to improve the power quality in a rural load fed from a wind driven permanent magnet synchronous generator (PMSG). The reference voltage is tracked by voltage source converter using a switching band scheme. A method of extracting the phasor symmetrical components that contain both integer and non integer harmonics and complex Fourier transform relation is proposed. In this paper, it is demonstrated that this device can tightly regulate the voltage at the load terminal when load draws integer, non integer harmonic current and sag and swell in the source side.


2015 ◽  
Vol 781 ◽  
pp. 300-303
Author(s):  
Khamhyo Phothilath ◽  
Kittipong Tonmitra ◽  
Pramin Artrit

The impact of pin type insulators may cause from the lightning impulse overvoltage that hits directly to them. To investigate this problem, this work applies the ATP Draw version 5.6 software to simulate the effect of pin type insulators. Therefore, the obtained results are showed that pin type insulators at pole P4 is closely the lightning strike point, has affected more than the poles P3-P1 and P5-P7. In addition, the conductor has been taken by the heat of over current flow through on it. The flashover and breakdown severity is on insulator upon the distance of them.


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