Phasor measurement units (PMUs) are rapidly being deployed in electric power networks across the globe. Wide-area measurement system (WAMS), which builds upon PMUs and fast communication links, is consequently emerging as an advanced monitoring and control infrastructure. Rapid adaptation of such devices and technologies has led the researchers to investigate multitude of challenges and pursue opportunities in synchrophasor measurement technology, PMU structural design, PMU placement, miscellaneous applications of PMU from local perspectives, and various WAMS functionalities from the system perspective. Relevant research articles appeared in the IEEE and IET publications from 1983 through 2014 are rigorously surveyed in this paper to represent a panorama of research progress lines. This bibliography will aid academic researchers and practicing engineers in adopting appropriate topics and will stimulate utilities toward development and implementation of software packages.

Synchrophasor Measurement Technology in Power Systems: Panorama and State-of-the-Art

This paper proposes a novel adaptive wide area backup protection scheme for transmission lines. In the proposed scheme, both the faulted line and fault location are determined by a limited number of synchronized phasor measurements. Based on phasor measurement unit placement and network topology, subsets of lines and buses called backup protection zones (BPZs) are formed. After a fault occurs in the transmission network, the sum of zero- and/or positive-sequence currents entering the faulted BPZ highly increases, and hence, the faulted BPZ can be determined. The linear least squares method is then used to determine the faulted line, as well as the fault location by voltage and current phasors of the faulted BPZ. Accordingly, the proposed scheme provides a closed-form and noniterative solution for the faulted line and fault location identification problem. On the other hand, it readily determines the faulted line regardless of the fault type, fault resistance, and measurement errors. To show the effectiveness of the method, it is applied to the WSCC 9-bus and IEEE 118-bus test systems. Simulation results verify successful identification of the faulted BPZ as well as the faulted line within the faulted BPZ with limited measurement points.

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An Adaptive PMU-Based Wide Area Backup Protection Scheme for Power Transmission Lines

This paper presents a synchronized phasor measurement-based wide-area backup protection scheme which compares the magnitude of sequence voltages of buses at a system protection center to identify the bus closest to the fault. Then, the sign of cosine of the angle between voltage and current at both ends of all lines connected to this bus are compared to identify the faulted branch. The technique is tested for various faults resulting in voltage/current inversion in a series-compensated line and during load encroachment and power swing conditions using data simulated through EMTDC/PSCAD for a nine-bus, three-machine power system. The scheme is found to be accurate and fast. With today's synchronized phasor measurement technology and communication system, the proposed scheme can overcome the limitations of the conventional backup protection scheme.

Wide-Area Measurement-Based Backup Protection for Power Network With Series Compensation

This paper presents a fast and robust wide-area backup protection scheme to detect the faulty condition and to identify the faulted line in a large power network The proposed methodology uses positive-sequence synchrophasor data captured by either digital relays with synchronization capability or phasor measurement units dispersed over the network The basic idea behind the new protection scheme is the comparison of bus voltage values calculated through dissimilar paths Upon occurrence of a fault, the faulty condition is first detected and the bus(es) connected to the faulted line is(are) determined Among transmission lines connected to the suspected bus(es), the faulted one is thereafter identified In addition to two-terminal transmission lines, multiterminal lines are also incorporated The performance of the proposed method is validated on the IEEE 57-bus test system in different fault conditions (fault type, fault location, and fault resistance) Discrimination of faulty and normal conditions is simulated by examining various stressed conditions, for example, load encroachment, generator outage, and power swing The data requirement of the proposed technique is analyzed as well To do so, a mathematical model for the optimal placement of measurement devices is developed and applied to different IEEE standard test systems

Synchrophasor-Based Wide-Area Backup Protection Scheme with Data Requirement Analysis

This paper presents a new wide-area backup protection scheme based on the phase angle of positive-sequence integrated impedance (PAPSII). The proposed scheme uses phasor measurement units (PMUs) that comply with standard C37.118.1-2011 for retrieving the phasor information. The PMUs provide the positive-sequence phasor information of the voltage and current signals at each and every bus of a system to a phasor data concentrator (PDC). The positive-sequence integrated impedance of each line of the system is extracted, and the PAPSII of each line is continuously monitored at the PDC. The values of the PAPSII help in identifying the faulted line of the power transmission system. The proposed scheme is extensively tested for different types of fault scenarios on a three-machine nine-bus power transmission network on a real-time digital simulator platform. Critical issues such as voltage inversion, current inversion, load encroachment, and the power swing are addressed in the proposed scheme. The test results indicate that the proposed scheme can overcome the limitations of existing backup protection schemes and can provide a reliable protection measure.

A New Wide-Area Backup Protection Scheme for Series-Compensated Transmission System

A novel wide area backup protection algorithm to identify fault branch based on the fault steady state component is proposed. Under normal conditions of the power system, subsets of buses called protection correlation regions (PCRs) are formed on the basis of the network topology and phasor measurement unit (PMU) placement. After the fault occurs, by analyzing the fault steady state component of differential current in each PCR, the fault correlation region is confirmed and then a fault correlation factor (FCF), is calculated in real time to locate the fault branch. The simulation results for the 10-generator 39-bus system verify that this method is able to easily identify fault branch with limited measurement points.

A. J. Arana

Papers

A Fault Steady State Component-Based Wide Area Backup Protection Algorithm