The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The characterization of the closed-loop delays in a wide-area control system (WACS) is an important foundation for further research. The method to estimate and measure the closed-loop delay in actual WACSs were proposed in this paper. Then, the closed-loop delays in the actual WACS in Guizhou Power Grid in China were measured and analyzed. Also, the measured delays were used to verify the normal distribution...
In this paper, a new planning methodology is proposed for existing distribution grids, considering both passive and active network measures. The method is designed to be tractable for large grids of any type, e.g., meshed or radial. It can be used as a decision-making tool by distribution system operators which need to decide whether to invest in new hardware, such as new lines and transformers, or...
The main task of the state estimator in power systems is the provision of the power system state accurately. In order to achieve this, the measurement set has to be validated by identifying erroneous measurements. This is usually achieved by using either the Chi-square or the Largest Normalized Residual test. In both tests, the estimated states that are provided by the state estimator and the measurement...
This paper develops a correlation index for Anomaly Detection System (ADS) to detect and identify wide area measurement attacks at sub-transmission level. Inspired by forensic analysis, we study the pattern of measurement attacks at sub-transmission power systems by developing an index of correlated substation attacks. The attacking strategy is reconstructed as a one stage two-level optimization problem...
The paper describes a REI-based procedure for estimating parameters of a dynamic model from measurements in the boundary buses/branches. Parameter identification of equivalent synchronous generators in fictitious buses is performed by Weighted Least Square (WLS) nonlinear optimization to minimize the difference between online measurements and transient responses of reduced power system.
In this paper, a technique for designing fixed parameter decentralized power system stabilizers (PSSs) for interconnected power systems is proposed. In the proposed method, local information available at each machine in the multimachine environment, is used to tune parameters of PSS. Conventional design techniques such as P-Vr frequency response approaches, and the method of residues are based on...
The increasing injections of energy from renewable energy sources far away from load centers have resulted in a more congested transmission grid. As the construction of new lines is costly, other options should be exploited as well. One possible solution is Dynamic Thermal Line Rating (DLR), which, instead of static thermal line rating, adapts the transmission capacity based on the expected weather...
Smart Grid security has motivated numerous researches from multiple disciplines. Among the recently discovered security challenges, the False Data Injection (FDI) has drawn great attention from power and energy, computer, and communication research community, because of its potential to manipulate measurements in state estimation (SE) without being identified by conventional bad data detection (BDD)...
Recently, many aspects of power system dynamic analysis, including oscillation identification, load model identification and system state estimation, are conducted based on the measurement data from phasor measurement unit (PMU). However, the impact of PMU measurement error, especially in power system dynamic process, has an assignable impact on these analysis results and thus cannot be neglected...
Generation in the Nordic power system is dominated by large number of hydro power plants, especially in Norway and Sweden. There are indications that, during the last decade, the frequency quality in the system has deteriorated; the number of minutes when the frequency stays outside the permissible range has been increasing. There is ongoing work to find the root of the problem and solutions to improve...
This paper presents a practical method for a real-time measurement of the ratio ρ = rneq / r (r = line resistance, rneq = equivalent neutral path resistance) of a three-phase four-wire distribution feeder and advocates the possibility of ignoring the zero-sequence voltage component due to its reduced magnitude in practical situations. The ratio ρ has a significant impact on the value of the apparent...
State estimation is a critical function in the energy management system that processes measurements from the field and determines the most likely state of the power system. As more sensing is added and wider areas need to be estimated in real time, the computational speed of state estimation becomes increasingly more important. This paper proposes a scalable method that uses automatic graph partitioning...
Maintenance work of power equipment plays an important role in ensuring the security and reliable operation of power system and promoting the economic efficiency of enterprises. This paper takes the actual operating status of in-service equipment into account, calculates the current failure rate based on health index to improve the equipment reliability assessment. The fuzzy age reduction based failure...
Vulnerability analysis of the State Estimation module have come under renewed interest in the control centres of a SCADA connected energy system. Existing researches show that the state estimation module can be compromised by a class of data integrity attacks known as ‘False Data Injection (FDI)’. The stealthy FDI attack construction strategy requires the knowledge of the power system topology and...
The primary challenge with high penetrations of solar power into power distribution feeders lies in the solar resource's inherent variability and uncertainty during partly cloudy days. To avoid unnecessary limitations to the rapid integration of PV to the grid, there is a need to understand and characterize PV variability from the prospective of utility operators and planners. To this end, this paper...
This paper presents the system design and the first practical experiences of a Distribution Area Monitoring System (DAMS) that was practically applied in the German 110 kV network. With regard to the involved components of the larger ICT system, the software architecture - including standardized Smart Grid communication protocols and interfaces - is described. As a main component, a linear state estimator...
Network delays and data-dropouts could have a significant impact on Cyber-Physical System (CPS). In this paper power grid with large-scale deployment of distributed and networked Phasor Measurement Units (PMUs) and wind energy resources is considered as an example of CPS. Modeling and simulation studies are done in a power system with 151 dynamic states for stabilizing electromechanical oscillations...
This paper presents a novel method to early predict the transient stability status of a power system after being subjected to a severe disturbance. The proposed technique is based on rate of change of voltage vs. voltage deviation (ROCOV-ΔV) characteristics of the post-disturbance voltage magnitudes obtained from synchrophasor measurements. Converging and diverging nature of the post-disturbance trajectories...
This paper presents an approach for generating simplified secondary circuit models with limited SCADA and PV micro-inverter measurement data. The proposed method is computationally efficient and can be utilized with typically available measurement data. The method is applied to models of three real U.S. utility feeders with PV micro-inverter measurements. The proposed simplified secondary circuit...
The grid frequency quality in the Nordic power system has been deteriorating during the last decade. To improve the situation, a better understanding of the system is needed. In this paper, a model of the Nordic power system dynamics with respect to normal operation frequency control is set up and compared with full-scale measurements on the system. The “60 s oscillation” of the grid frequency is...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.