Research
Research
My major area of interest is in the transmission line protection, specifically distance protection. My future interest lies in in developing a distance protection algorithm for the future grid with high penetration of the renewables.
Mariselvam Arumuga and Maddikara Jaya Bharata Reddy, "An Intelligent Distance Relay Sensing Methodology Immune to Power Swing and Load Encroachment," in IEEE Sensors Journal, vol. 23, no. 1, pp. 800-811, 1 Jan.1, 2023, DOI: 10.1109/JSEN.2022.3223905 .
Mariselvam Arumuga and Maddikara Jaya Bharata Reddy, "Critical analysis of the effect of source impedance ratio and power flow on the performance of the distance relay during non-fault and fault conditions," in Electrical Engineering, 105,193–205 (2023), ISSN:0948-7921, (SCIE) DOI: 10.1007/s00202-022-01659-5.
Mariselvam Arumuga and Maddikara Jaya Bharata Reddy, "Distance Protection Methodology for Detection of Faulted Phase and Fault Along With Power Swing Using Apparent Impedance," in IEEE Access, vol. 10, pp. 43583-43597, ISSN: 2169-3536, 19 April 2022, (SCIE) DOI: 10.1109/ACCESS.2022.3168563.
Mariselvam Arumuga, Geethanjali M, and Maddikara Jaya Bharata Reddy ”Adaptive System Integrity Protection Scheme Constrained by Minimum Loss of Service Using PMU Data,” National Power System Conference (2022), IIT Delhi, Dec 17-19 2022.
Title: A Novel Secure and Dependable Distance Protection Methodology Immune to Stressed Conditions
Abstract: Increased use of electrical energy for various applications and the overall increase in the global energy demand are pushing the power grid to operate at the verge of its limits with reduced margins. Hence, the transmission system is loaded to the maximum extent possible with reduced security. Therefore, a single contingency can lead to a cascade tripping and a blackout. Global reports on causes of blackouts mostly point to the maloperation of the distance protection of the transmission line during stressed conditions like power swing and load encroachment. Hence, distance protection should be made intelligent enough to distinguish a fault or stressed condition and avoid maloperation.
A distance relay operates based on apparent impedance computed using inputs from potential and current transformers. The distance relay sees the apparent impedance inside its operating region during a fault condition, issues the trip signal to the circuit breaker, and isolates the faulted line. However, there are certain stressed conditions like power swing and load encroachment, during which the apparent impedance might enter the operating region despite no fault. Without some vigil on these stressed conditions, the distance relay can maloperate.
Conventional distance relays use additional techniques to detect such stressed conditions and block the distance relay during such conditions. Schemes like blinders or concentric characteristics are used to detect a power swing condition and block the relay. The relay will be unblocked on any unsymmetrical fault during the block period. However, a symmetrical fault goes undetected during such a block period and can lead to a blackout in the worst-case scenario. Another drawback is that the concentric characteristics' settings depend on the system's inertia. The settings may not detect the power swing at reduced inertia.
On the other hand, to avoid maloperation during load encroachment 30° region in Zone-2 and Zone-3 around the R-axis in the R-X plane of the distance relay is blocked based on the assumption that the power factor of the power flow in the transmission line will be around 0.866 (cos (30°). However, a highly reactive load encroachment that can occur during contingencies can lead to the appearance of the apparent impedance outside the 30° and can cause maloperation.
To overcome these challenges with the conventional distance relay, in this thesis, a novel distance protection methodology that is immune to power swing and load encroachment conditions and, at the same time, capable of detecting symmetrical and unsymmetrical faults that can occur during normal operating conditions or the stressed conditions is proposed. The research work started with critically analysing the apparent impedance behaviour during a symmetrical fault, power swing, and load encroachment in a simple two-source equivalent system. It is found that the apparent impedance enters the protective zone characteristics from the extreme right regions of Zone-2 and Zone-3 during power swing and load encroachment. On the other hand, during a symmetrical fault, the apparent impedance lies on the line impedance region irrespective of the value of the fault resistance. Hence, this distinguishing feature between a symmetrical fault and a stressed condition is used to develop a novel distance protection methodology.
The proposed methodology divides the Zone-2 and Zone-3 of the protective zone characteristics into supervised and unsupervised regions. The supervised regions in Zone-2 and Zone-3 are the extreme right regions of Zone-2 and Zone-3, where the apparent impedance encroaches during stressed conditions like power swing and load encroachment. Hence, whenever the apparent impedance appears in these supervised regions, an additional criterion that ascertains a fault condition is to be satisfied in addition to the zone reach and time criterion to issue the trip signal. In this way, the maloperations of the distance relay during the stressed conditions are avoided, as just satisfying the reach and time criterion will not lead to the issuance of the trip signal. Also, the symmetrical fault can be detected as the distance relay is not blocked. Hence, the proposed methodology improves dependability without compromising the security aspect of transmission line protection.
The proposed methodology is validated in MATLAB/Simulink environment in the WSCC 9-Bus System and the 24 Bus 400 kV Grid of the Southern Region of the Indian Power Grid (SRIPG 24-Bus System). The results from case studies of power swing and load encroachment conditions demonstrated the strength of the proposed methodology to survive the stressed conditions. The results from numerous case studies of symmetrical and unsymmetrical faults during normal operating conditions and during stressed conditions like power swing and load encroachment demonstrated the efficacy of the proposed methodology in detecting a fault during any given situation within one cycle.
Further, the real-time models of the WSCC 9-Bus System and the distance relay employing the proposed methodology were developed and deployed in the Opal-RT Real-Time Digital Simulation (RTDS) and validated for various case studies. The results from numerous case studies of faults, power swing, faults during power swing, load encroachment, and faults during load encroachment further demonstrate the real-time validity of the proposed methodology in surviving real-time stressed conditions and the ability to detect any fault during normal and stressed conditions within one cycle.
The distinguishing feature of the proposed methodology is its ability to survive the power swing without using techniques like blinders or concentric characteristics and survive the load encroachment condition without blocking the 30° region. Also, the proposed methodology can detect symmetrical and unsymmetrical faults during normal operating, power swing and load encroachment conditions within one cycle. The results from case studies in RTDS further demonstrate the real-time applicability of the proposed methodology. Hence, the proposed methodology can be implemented in a practical distance relay and improve the overall reliability of distance protection.
Title: System Integrity Protection Scheme (SIPS) using Phasor Measurement Unit (PMU) Data
A System Integrity Protection Scheme (SIPS) for a critical line in IEEE 24 Bus Reliability Test System using Phasor Measurement Unit (PMU) data is designed based on Linear Sensitivity Factors.
The existing SIPS in most of the power systems in the world including the Indian grid uses fixed loads to be rejected irrespective of the load conditions and amount of overload to be relieved. This is due to the lack of real time data. However, with the increased use of Phasor Measurement Units it is possible to use real time data and the SIPS can be made adaptive. The
proposed scheme adaptively chooses best combination of loads to be shed with minimum loss of service.
A critical line is identified in IEEE 24 Bus System for a given load condition, loss of which would lead to cascaded tripping of other lines due to overload. In the case of loss of the critical line the overloaded lines are identified using real time data available from the PMUs and the loads are rejected to relieve the overload before the lines being tripped due to overload. Generation Shift Sensitivity Factors (GSSF) are used to estimate the load to be rejected. An algorithm to identify the best possible combination of loads to be rejected with minimum loss of service is developed.
Two different load conditions are tested to prove that the algorithm adaptively chooses the loads to be shed based on the present load conditions.
The IEEE 24 Bus Reliability Test System is developed in Dig SILENT PowerFactory 15.1 and the algorithm is developed in MATLAB 8.1
A project is carried out on ‘Synchronized Measurement Based Backup Protection of Series Compensated Lines’ under the guidance of Dr. B. K. Panigrahi at IIT Delhi from18th May 2015 to 10th July 2015.