A new component transformation is proposed for six-phase systems, applicable for six-phase transmission lines studies, allowing its representation by two uncoupled three-phase lines. Cyclic transposition allows additional properties of the two three-phase groups that are presented. Transposed and nontransposed six-phase lines are analyzed, and the main characteristics of their natural modes are discussed in the frequency domain. An eigenvector normalization method for nontransposed lines that assures null modal conductance and, as a consequence, positive modal resistance, is proposed. Numeric results are presented in relation to an example line of 500 kV/sub rms/, phase to ground, with characteristic power of 5176 MW. >

Six-phase transmission line-propagation characteristics and new three-phase representation

The invention describes a method, system, device, and computer-readable medium having computer-executable instructions for classifying faults on an electrical power line. In particular, the invention permits the classification of crossover faults using a local measurement technique. The inventive method includes providing a first electrical power transmission line and a second electrical power transmission line, and monitoring the first electrical power transmission line to identify a crossover fault occurring between the first and the second electrical power transmission lines.

Crossover fault classification for power lines with parallel circuits

The demand of electrical energy is continuously increasing. High phase order transmission system is a viable alternative due to increasing costs of right of way. Six phase transmission lines can carry more power for same phase to phase voltage with the same right of way economically. Protection of six phase transmission lines has been a very challenging task. Earlier simulations of six phase transmission line have been done in PSCAD/EMTDC software. In this paper MATLAB® software and its associated Simulink® and Simpowersystem® toolboxes have been used to simulate the six phase transmission line. Application of Artificial Neural Network for protection of six phase transmission line against ground faults is presented, which the authors believe has not been reported earlier. Fundamental components of six phase voltages and currents have been used as inputs for training of the artificial neural network for detection and classification of faulted phase using neural network toolbox of MATLAB®. A sample 765 kV system of 60 km length has been selected for study. The study takes into account the effect of variation in fault inception angle, fault distance location and fault resistance. The results indicate the suitability of proposed technique and its adaptability to changing system conditions.

Detection and classification of faults on six phase transmission line using ANN

The paper introduces a generalized method for analysis of multiple, simultaneous short circuit, open circuit, and open circuit falling conductor faults in mixed three-phase and six-phase power systems with untransposed lines. The method is systematic and suitable for all types of faults, any number of simultaneous faults, and any number of phases. Calculation of all network unbalanced voltages and currents during faults is done in one straightforward step. Coupling among sequence networks in untransposed transmission lines is accounted for. Coupling between the three-sequence networks of the three-phase part and the six-sequence networks of six-phase part is also derived. The method is applied also for transient stability study of mixed three-phase and six-phase power systems during any type of faults. Detailed derivation of the governing equations in each part is presented. Simulation results on the IEEE 300-bus system and the IEEE 30-bus system are given to validate the proposed method.

https://cyberleninka.org/article/n/579368.pdf

Analysis of simultaneous unbalanced short circuit and open conductor faults in power systems with untransposed lines and six-phase sections

High phase order transmission system is being considered a viable alternative for increasing the power transmission capability of overhead electric power transmission over existing right-of-way This paper presents the faults analysis of six-phase transmission system In this context, fault analysis has been conducted on the Goudey-Oakdale 2-bus test system The results of these investigations are presented in the form of typical time responses The PSCAD/EMTDC is used for the simulation studies

Fault analysis on double three-phase to six-phase converted transmission line

The use of six-phase (and other higher order phase) systems for power transmission was proposed as an alternative for using electrical rights-of-way more effectively and efficiently. One of the important items in applying the six-phase alternative in transmission planning is the design of an adequate protective scheme. This requires a detailed and realistic fault analysis. The 23 significant fault types (symmetrical or asymmetrical) that can occur in six-phase power systems are analyzed. The theory of three-phase symmetrical components is used to develop a method for such analysis. The validity of the proposed method is checked by application to a simple system under a single line-to-ground fault, and three line-to-ground, five line-to-ground, and six line-to-ground faults. The advantage of the method is its applicability to all significant faults that occur on six-phase power systems. >

M.K. El-Sherbiny

Papers

A method of analyzing unsymmetrical faults on six-phase power systems