Fdtd analysis
The magnitudes of voltage over the time at observation points are also given in Fig. The waveform along the main line of L1 becomes more and more distorted due to the repeat reflection and transmission of travelling-wave in the junction over time. The peak values of both the reflective wave and the transmissive wave are less than that of the transient wavefront. At the same time this incipient wavefront is transmitted through the fork junction into both lines of L2 and 元 and at this time these transmitted travelling waves into lines of L2 and 元 become positive transmissive waves. After that negative reflective wave propagates back along the original line. When the right wavefront arrives at the fork junction the reflection and transmission phenomena of this wave appear. 5 that the dual incipient wavefront propagates from the fault location to both terminals of the main line L1 after transient fault occurs. The dynamic process of travelling-wave propagation is shown in Fig. The distance of L f between fault location and the source terminal is 90 m and the amplitude of this fault represented by Gaussian pulse is 1.56 V. The total length of main line L1, main line L2, and branch line 元 are 100.1 m, 50.1 m, and 30.1 m respectively. Simulation parameters are configured that Δ t is 0.1 ns Δ x is 0.1 m, and the total number of Δ t is 10500. In order to verify that this method is feasible and efficient in analyzing the attenuation of transient fault induced travelling-wave in multi-branch networks, the parameters of this network were configured and the expected simulation results were obtained in Section 3, followed by the conclusions. This paper derived the telegraph equations of the multi-branch distribution network in difference expression and these equation boundary conditions were determined in Section 2. The effect of fork junction of multi-branch networks is thus concerned gradually to further discuss the characteristic of the travelling-wave propagation as in. Some related experiments for multi-branch networks as in indicated that the characteristic of the actual travelling-wave attenuation is inconsistent with the theoretical damping characteristic related to resistive and capacitive elements. However, the technological problems on the application of the traveling-wave based method in distribution networks still to be further resolved.
While travelling-wave based location method has been widely applied in high voltage transmission line for online fault location. As a result, this approach is hard to be used for online location. In terms of signal transmission problems in networks with constraints, a hybrid evolutionary approach is proposed in which is time-consuming for the large number of particles.
Fdtd analysis series#
In general, series resistive elements result in the attenuation of the travelling-wave and parallel capacitive elements result in the suppression of the incipient wavefront. However, the analysis on the attenuation of travelling-wave affected by the fork junction of multi-branch networks based on the FDTD method has not been found in published articles. The lightning surges on a distribution line are analyzed effectively by the FDTD method as in. Due to the high performance in fast calculation the FDTD method is gradually applied to the field of power system protection for researching the travelling-wave propagation induced by transient faults such as lightning or vegetation-related failures. Among these methods the FDTD method has a distinct advantage in fast calculation of this dynamic propagation due to the direct calculation in the time domain compared with BLT equation based method. Many methods are available to calculating the process of the travelling-wave propagation, such as, BLT equation based method and FDTD method. In order to understand the reason that the travelling wave is attenuated, a clear dynamic process of this travelling wave propagation is needed urgently. However, transient fault is hard to be located due to the attenuation of the travelling wave induced by this fault particularly in multi-branch distribution networks. With the rapid development of the Ubiquitous Internet of Things in Electricity, the location of transient fault is more and more concerned to improve the maintenance ability for distribution networks.
This fault severely affects the service quality of the power supply and the reclosure is one of the effective measures taken to reduce the losses bringing about by this fault. The earth fault particularly transient fault occurs frequently in distribution networks.