Jun Li - IEEE Xplore Author Profile

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Utilities today are facing unprecedented challenges due to more stringent regulations, environmental concerns, and a growing demand for reliable electricity. Meanwhile, according to U.S. Department of Energy?s statistics, 70% of the grid's transmission lines and power transformers are more than 25 years old. Without upgrades and enhancements, the grid will continue to age, increasing the risk of s...Show More
Intentional islanding is often conducted as the last resort to preserve the electric grid from severe blackouts. The intentional islanding scheme deliberately segregates the power system into a number of self-sustained islands to enhance the transient stability of the power network. In this study, a spectral clustering algorithm is presented to obtain an islanding solution, which results in minima...Show More
Early prediction of cascade events outages followed by immediate and proper control actions can prevent major blackouts. This paper introduces a novel method to predict cascade event outage at early stage and mitigate it with proper control strategy. In the first step, methodology employs sparsely located phasor measurement units to detect disturbances using electromechanical oscillation propagati...Show More
Controlled islanding scheme is frequently considered as the final solution to retain power system operation under cascading event outages which can lead to a major blackout. The islanding scheme can improve the power system transient stability by preserving stable areas from further outages as well as reducing the complexity and overall time required for restoration process. In this paper a constr...Show More
This paper presents a novel system-wide fault-location method for transmission lines utilizing electromechanical-wave oscillation propagation phenomena. The method uses synchrophasor measurements during disturbances obtained from phasor measurement units sparsely located in the network. The method determines the time of arrival of electromechanical waves propagating from the fault point to sparsel...Show More
Several major blackouts were caused by distance relay mis-operation. Distance relay mis-operation may occur following a large disturbance in the system causing power swing and out-of-step conditions. If an on-line fault analysis tool is able to detect power swing or out-of-step conditions and indicate mis-operation of relays, the operator may be notified to switch back the healthy transmission lin...Show More
The topology (transmission line) switching to achieve economic and reliability gains in the power grid has been proposed some time ago. This approach did not gain much attention until recently when large penetration of renewable generation created incentives to use transmission line switching to control sudden changes in power flows and mitigate contingencies caused by the generation variability. ...Show More
An automated analysis approach, which can automatically characterize fault and subsequent relay operation, is the focus of this paper. It utilizes synchronized samples captured during transients from both ends of the transmission line to detect, classify, and locate transmission-line faults and can verify that the tripped line has indeed experienced a fault. The proposed method is tested for sever...Show More
The tapped lines are usually used to supply a customer such as small communities or industrial facilities with an economic solution that is less expensive than building a full substation. Locating faults in such lines are difficult due to the effect of infeed/outfeed current from tapped lines as well as reactance effect. The proposed method applies generalized models of fault loop voltage and curr...Show More
This paper describes a novel adaptive out-of-step detection algorithm based on dissimilar measurement approaches. Two superimposed measurements enable the algorithm to detect fast as well as slow power swings. Both methods recognize power swings right from the beginning of the swing impedance movement. The first principle is based on continuous rate-of-change measurement of the traveling swing imp...Show More
This paper presences an accurate and robust fault location algorithm for transmission lines utilizing Static Synchronous Series Compensator (SSSC). The presence of SSSC on a transmission line has a great influence on the measured impedance at the relaying point. Firstly a detailed model of the SSSC and its control is proposed and then a precise fault location algorithm employing adaptive neuro fuz...Show More
Nowadays Wind turbines are used over a wide area as they are environmentally favorably means to product energy without emissions and moreover the fuel is wind which is free for use. Wind turbines are often installed in mountainous area where the soil resistivity and isokeraunic level is high. When the soil resistance is high, the potential rise caused by lightning strike to a wind turbine is more ...Show More
Any sudden change in the configuration or the loading of an electrical network causes power swing between the load concentrations of the network. Power swing can affect the distance relay performance by entering the impedance locus into protection zone of the relay causing unnecessary tripping. In this paper a novel technique to prevent the distance relay from tripping during power swing is presen...Show More
A reliable islanding detection method is one of the most important function of a well designed inverter based distributed generation (DG) system. Active islanding detection methods have negligible non-detection zone, but they bring some power quality issues to the network. In this paper an islanding detection method which addresses constant current inverter based DGs is introduced. It has both hig...Show More
This paper presents a fault location algorithm for single phase to ground faults on three terminal transmission lines. The conventional fault location methods, using one-terminal ac voltage and current are not applicable to the multi-terminal systems. So, the indication of the faulted section and fault distance estimation is performed by using three-phase current and voltage of the terminal at whi...Show More
In both vertically integrated and restructured power systems, it is desired to transmit power to every parts of the network without any limits resulted from congestion and consequently avoiding inefficiency in generation dispatch. In this paper, in order to eliminate power system's congestion, distributed generation (DG) is employed. DG's have nonlinear impacts on the power system characteristics ...Show More
A smart grid will integrate extensive distributed resources such as local generation sources, Plug-in Hybrid Electric Vehicles (PHEVs) and demand response (DR) programs. By using smart metering, advanced metering infrastructure (AMI) facilitates consumer participation in DR programs and changes the consumption pattern of residential user via tariff schemes for electrical energy. In addition, the s...Show More
Any sudden change in the configuration or the loading of an electrical network causes power swing between the load concentrations of the network. In order to prevent the distance protection from tripping during such conditions, a power swing blocking is utilized. This paper compares and evaluates the performance of several power swing detection algorithms in the presence of series compensation and...Show More
In this paper, a new method is introduced which is based on the application of adaptive neuro fuzzy method to investigate transformer inrush current. This algorithm uses the second harmonic and the dead angle methods joint to each other utilizes the neuro fuzzy technique. In this method, an inrush detector is defined as an output of neuro fuzzy system. An eligible advantage of this method is evalu...Show More