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This paper proposes a single-switch circuit derived from buck boost converter which converts input DC voltage into desirable AC and DC voltages. The switching strategy used is sinusoidal pulse width modulation with a DC offset-known as augmented sinusoidal pulse width modulation (ASPWM). The ASPWM waveform is obtained by sine triangle comparison method where the modulating signal is the combination...
This paper proposes a novel hybrid converter derived from a conventional Buck Boost DC-DC Converter. The principle of Augmented Sinusoidal Pulse Width Modulation (ASPWM) is used to derive the hybrid topology. It provides both AC and DC voltages using a single DC source as input. As a result of ASPWM switching, the voltage across the Buck-Boost stage inductor will contain a line frequency component,...
There are some limitations of the current web like high recall, low precision or search result are highly sensitive to vocabulary because of this next generation web i.e., Semantic web is used. In Semantic Web information is given in well defined and meaningful manner. Proposed system takes the advantages of Semantic web. In proposed approach we used Google Map API to create Map and used as front...
This paper presents a novel approach for calibration of Instrument Transformers (ITs) using synchrophasor data. The proposed algorithm detects the presence of bad data using Largest Normalized Residual (LNR) test in a step and discards the corresponding measurements. This method is intended to work as a filtering scheme that can significantly improve the accuracy of Current Transformers (CT) and Capacitive...
A new current differential protection scheme for high voltage double circuit transmission lines in the modal domain is proposed in this paper. This method is based on decoupling the mutually coupled lines using modal transformation matrix. Synchronized current and voltage phasors from both the ends are utilized and converted to modal values. The lines are modeled with equivalent-π model. Current differential...
This paper proposes a novel single-switch circuit which converts input DC voltage into desirable AC and DC voltages. The switch is controlled to accomplish maximum power point tracking and maintain the desired AC and DC voltage levels. The circuit utilizes the voltage excursions across the intermediate stage inductor to obtain the AC voltage. The required 50 Hz component is obtained by adopting sinusoidal...
This paper proposes a new fault location technique for EHV double circuit transmission lines using synchronized current and voltage measurements from both ends. Double circuit lines faces difficulties in fault location due to mutual coupling. Modal transformation is used to decouple the coupled transmission line equations. Fault detection and location indices in terms of modal components of measured...
Distance relays face the difficulty of differentiating a power swing from the three phase faults leading to their unsecured tripping. This paper proposes a novel unblocking algorithm to detect the symmetrical faults during power swing using only the local current measurements. During power swing, the current signals resemble an amplitude modulated waveform; the characteristics of which are dependant...
This paper presents a novel scheme for fault detection, classification and location which compensate for phase angle error due to line charging current using synchronized phasor measurements in SMART GRID. The work includes fault detection in the phase domain with the extraction of synchronization operator from the measurements available from two ends of transmission line. Synchronization operator...
Mal-operation of distance relays due to power swing has resulted in the development of several power swing blocking algorithms. A blinded distance relay is incapable of issuing trip signal in case faults occur during power swing. Detection of three phase faults during power swing imposes a challenge, owing to the symmetrical nature of both the power swing and three phase faults. This paper proposes...
Accurate measurement of transmission line parameters is important for power system protection applications, especially distance relays whose zone settings are based on positive sequence line impedance. This paper presents a new method to estimate all the parameters for double circuit transmission lines. Double circuit transmission lines are widely used in the power system and are important from reliability,...
This paper presents a new algorithm for fault detection, classification and location which compensate for phase angle error due to line charging current using synchronised phasor measurements in SMART GRID. The paper includes fault detection with combination of phase and sequence components by using ground distance relay expression in terms of sending and receiving end voltages and currents. Here...
Secure operation of distance relays is of utmost importance to ensure the integrity of a power system. Mal-operation of distance relay's unblocking function during power swing is possible in case of transmission lines along the same right of way. An attempt is made in this paper to make the distance relay robust by utilising the available synchronised measurements. A differential active power approach...
The segregated phase comparison technique is a notable form of differential protection which compares the phase angle of end currents of a transmission line. The literature shows that phase differential protection serves as a better option for transmission-line protection due to its simplicity, sensitivity, selectivity and comprehensibility. However, line-charging current causes a significant error...
Segregated phase comparison technique is a special form of current differential protection. It takes into account the difference of phase angle of currents entering at one terminal and current leaving out of other terminal of transmission line. Line charging current causes significant change in phase angle of two end currents of a transmission line. This paper presents novel phase comparison technique...
Segregated phase comparison technique, a special form of current differential protection is widely applied for the protection of transmission line due its simplicity. It takes into account the difference of phase angle of currents at two terminals of transmission line. In this paper, one Relay/PMU is placed at sending end and to calculate receiving end voltage and currents; data is used from neighbor...
In this paper, the analytical and simulation results of the application of adaptive distance protection scheme for the transmission line incorporating Static Var Compensator (SVC) connected at the mid-point is presented. The mal-operation of the distance protection for the transmission line with SVC at various locations are studied. The simulation results show the under-reaching and over-reaching...
This paper presents a comparative evaluation of three commonly used Out-of-step (OOS) detection techniques namely double blinder method, R-Rdot method, swing centre voltage (SCV) and its rate of change method. The simulations were carried out on PSCAD. The three methods have been implemented and studied for their speed of detection. The study indicated that R-Rdot relays are faster however SCV scheme...
Although there has been a practice of transposition of transmission lines, most of the real life EHV/UHV lines are untransposed. The distance protection of such lines becomes very complicated. With the advent of Global Positioning System (GPS) and Fiber optics technology, current differential protection can be a better choice for such lines. This paper proposes current differential protection scheme...
Distance relays used for transmission line protection can mal-operate on power swing. This paper presents protection schemes for out of step detection based on synchronized phasor measurement. Voltages and currents at both the ends of a transmission line are used to derive the parameters required for designing these schemes. The proposed schemes can distinguish stable and unstable power swing and...
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