Study of Ultra-High-Speed Protection of Transmission Lines Using a Directional Comparison Scheme of Transient Energy

Abstract

This paper presents an ultra-high-speed (UHS) pilot protection of transmission lines based on directional comparison of the transient energy (TE). The proposed method can easily determine the fault direction by calculating the TE during a very short period. The obtained fault directions at both ends of the protected line will be compared to discriminate the internal faults. In contrast to the conventional UHS protection using initial traveling waves, this method is able to correctly operate even when the fault inception angle is at zero crossing. In order to correctly indicate the fault direction and improve its sensitivity, the data processing window has been reasonably chosen to obtain TE by analyzing the polarity variation of the transient power. A large number of various fault scenarios have been simulated on the 750-kV system using PSCAD/EMTDC and the results show that the proposed method is able to discriminate the internal fault very rapidly and reliably. Index Terms-transient energy, ultra-high-speed, directional comparison, EHV/UHV transmission lines M N RM RN optic fiber channel Q P communication communication Fig. 5. The directional comparison relaying scheme.We suppose a fault occurring on the line. The algorithm of the starting unit is designed as follows [14].

Multi-scale morphological gradient algorithm based ultra-high-speed directional transmission line protection for internal and external fault discrimination

“…It follows from (19) that ∆v B (t) and ∆i B (t) have the same polarity. This result in the following directional detection criteria:…”

“…We also deduce, at the fault point, that the voltage of the fictitious superimposed source and the steady-state voltage are equal in magnitude but of opposite sign. In fact, noting that ∆v F (t) = ∆v(x F , t) and that we haveṽ F (t) =ṽ(x F , t) = 0, we obtain then from equation 12the following relation : Considering that the superimposed quantities are directly related to to the fault, they should possess properties in relation to the directionality of the fault [19], [20]. In order to exhibit these properties, let's take for instance, as shown in Figure 6, a transmission system composed of two lines in which a fault is generated at point F at t F = 0.…”

“…Since the superimposed quantities contain information about the fault direction, as it has been shown earlier, the steady-state quantities must be removed, hence the use of the MSMGA [16] , respectively. They represent the superimposed (or transient) components, and replacing ∆v A (t), ∆i A (t), ∆v B (t) and ∆i B (t) in (17), (18) and (19), the fault direction can be determined in practice according to the following rules:…”

Autonomous Operation of Microgrid and Minimization of Fault in Case of Failure in High-Voltage Lines

“…In another study, protection coordination has been studied to prevent possible failure [5]. In another study, ultra-high-speed pilot protection of transmission lines has been presented based on the directional comparison of transient energy [14]. In another study on protection schemes, a complementary fault identification scheme has been proposed for threesupply high-voltage transmission lines [15].…”

Optimization-Based Settingless Algorithm Combining Protection and Fault Identification

“…While it is naturally slower than the TW-based approach, it does not have the aforementioned problems of the TW protection algorithms. The authors in [6]- [8] propose protection algorithms based on incremental quantities, which are fault-generated voltages and currents. Particular combinations of the incremental quantities are compared to thresholds to classify internal and external faults.…”