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Reliable operation of smart power grids depends on situational awareness made possible by real time system monitoring and accurate system condition estimation. Unfortunately, the tools used for real time system monitoring, which include supervisory control and data acquisition (SCADA) systems and phasor measurement units (PMU), are vulnerable to cyber-attacks due to the necessity of network connectivity...
Updating current swell for each feeder is one of stage of fault localization considering impedance based method. Estimation formula was adopted based on impedance line and load value. This paper investigate the impact of single and paralel impedance load to the accuracy of current swell estimation in the each feeder. Three Phase to ground fault (LLLGF) was simulated using the PSCAD simulation program...
The increasing share of distributed generation poses risks to the selectivity and reliability of power system protection. To begin with, this paper presents a selection of currently faced challenges, which lead to errors in locating of faults and secure functionality. As a result of the theoretical analyses, adaptive settings based on the current state of the protected electrical system are deducted...
A fully observable power system is possible with linear state estimation algorithms with exclusive use of synchronized measurements obtained from PMUs. The objective of full observability is achieved by placement of the PMUs at specific locations in power system instead of installing at every bus in the network. The calculation of mimimum number of PMUs and their locations is an optimization problem...
This paper presents a novel method to describe battery degradation. We use the concept of degradation maps to model the incremental charge capacity loss as a function of discrete battery control actions and state of charge. The maps can be scaled to represent any battery system rating in capacity and power. Their convex piece-wise affine representations allow for tractable optimal control formulations...
The paper considers the method for measurement of active and inductive resistances of the power line supplying career excavators based on mathematical processing of current and voltage at the input of the excavator in two modes of operation — power consumption and power recuperation during the excavation cycle. Parameters of measurement errors when using the line transducers of different class index...
This paper describes the optimal Phasor Measurement Units (PMUs) placement algorithm based on the Integer Linear Programming formulation. This method is based on minimizing of the measuring devices' number in a grid to provide the power system observability in [n-1] security. The N-1 criterion is preservation of a stable operation mode of the power grid in case of sudden loss of one of lines or outage...
This paper aims at finding a minimal placement technique for placing Phasor measuring units for reducing the cost of state estimate. The method used in this technique is binary integer linear programming. The results shows that the method adopted can be effectively used in practical. This paper suggests the use of phasor measurement units for improving power system state estimation and observebility...
The electric power network is a fundamental system that is vulnerable to the effects of space weather and geomagnetically induced currents. Low-cost sensing technologies can be deployed to reduce the impact and improve mitigation measures towards space weather. Magnetic sensing using solid state devices has increased due to improved sensitivity, abundant availability and reduced costs. In this paper...
Power engineering is facing major changes - some of them are captured by the smart grids newly adopted paradigm, while others are perceived as external impact of technological evolution in the traditional topics, like measurements. Here the innovation is usually reduced to smart metering initiatives. However, measurement technology is acknowledged as being a fundamental layer in the endeavor of setting...
The Smart distribution system initiative requires an increased usage of the distribution feeder-level communication infrastructure to improve automation. Using a distributed sensor network for monitoring the distribution system is proposed by various researchers. Such distributed sensor communication architecture requires information to be received within an allowable delay and a minimum processing...
A method for defining the inertia constant of a generating unit is proposed. It is based on a synchrophasor measurements approximation using the generator rotor swing equation. The input includes the measurements of the generator active power and rotor angle during electromechanical transients. The approach was validated by means of a mathematical simulation, experiments on the physical model and...
Phasor Measurement Unit (PMU) provides both magnitude and phase information of current and voltage signals with appropriate time stamp which is very useful in controlling power system networks in real time. Consequently, PMU is considered as one of the most significant measurement devices for complete observability of the future electricity grids. But placing PMU in every bus of the network is not...
This paper presents a new mixed-integer linear programming formulation of the optimal phasor measurement units (PMUs) placement problem when considering the topological observability of the power system. Different from other formulations, decision variables are associated with phasor measurements, but not with PMUs. This approach makes it easy to take into account the availability of PMU measuring...
The evolution of distribution networks from passive to active distribution systems puts new requirements on the monitoring and control capabilities of these systems. The development of state estimation algorithms to gain insight in the actual system state of a distribution network has resulted in a wide range of distributed and decentralized algorithms that make use of parallel computing to deal with...
This paper proposes an optimal Phasor Measurement Unit (PMU) placement method based on a modified version of the well-known binary integer linear programming formulation, which will utilize the installed PMUs and conventional measurements, i.e. active and reactive power flow and power injection measurements, to reduce the number of PMUs to be placed required for system observability. The proposed...
The new possibilities, associated with open access and the operation of the transmission network under energy market rules keeping reliability as a central issue, pilot to the need of new models for state estimation (SE) of power systems. This paper proposes one new scheme of SE which is based on current measurements using a linear measurement model with a constant observation matrix comprising of...
Phasor measurement units (PMUs) are being deployed in increasing numbers in power systems. Thus, it is not unrealistic to expect that in the not so distant future, utilization of PMU measurements directly and exclusively for static state estimation will become a viable alternative to traditional SCADA-based static state estimation. This paper considers such a future where a robust linear state estimator...
This paper investigates the sparse recovery models for bad data detection and state estimation in power networks. Two sparse models, the sparse L1-relaxation model (L1-R) and the multi-stage convex relaxation model (Capped-L1), are compared with the weighted least absolute value (WLAV) in the aspects of the bad data processing capacity and the computational efficiency. Numerical tests are conducted...
Pulsed power thyristors have been widely used in pulsed power systems due to their controllability, large through-flow capacity and high repetition frequency. To study the device's electrical characteristics and the circuit transient process, based on research of reverse recovery process of pulse thyristor, a macro model of pulsed power thyristor applying to MATLAB/Simulink software platform was established...
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