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.
This paper presents a novel algorithm for secondary current signal segmentation of saturated current transformer (CT) using three morphological gradient-based detectors. The saturation onset detector is used to monitor the occurrence of saturation and then trigger the positive/negative segmentation detector, which are designed to locate the starting point and the ending point of CT saturation. The...
The present work deals with a new energy management control scheme to regulate the battery discharge/charge rates (rate-limit) for a hybrid energy storage system (HESS), consisting of battery and supercapacitor. In general, batteries are used to supply slow transient (or steady state) load demand, due to its inherent properties of low power density and high energy density. The state of charge (SOC)...
This paper proposes a space vector modulation based dc-link capacitor voltage balancing technique for a five-level multiple-pole multilevel diode-clamped (M2DCI) inverter. The new five-level inverter contains lesser number of clamping diodes compared to the conventional five-level diode-clamped inverter (DCI) topology and does not require any extra balancing circuits to maintain balanced voltages...
DC Independent System Operator (DC-ISO) is a revolutionary concept; a single entity designed to coordinate, to control and monitor the operation of the DC transmission system. It will be responsible for ensuring the reliability and security of the VSC-HVDC meshed networks in real-time and co-ordinate the supply of and demand for electricity, in a manner that avoids violations of technical and economic...
To meet the increasing demand of electric energy, the distributed generation has been put in more and more applications. Being the key part of the distributed generation, the inverter may break down, which makes the normal generation unavailable. To solve this problem, this paper proposes a reconfigurable inverter which based on paralleled similar modules. And the reconfiguration method is designed...
This paper presents an evolutionary algorithm, reference point based multi-objective group search optimizer using non-dominated sorting approach (r-NSGSO), for optimal power flow problem with multiple objectives. First, the six objectives of optimal power flow are reduced to two objectives which represent the secure and economic indices, respectively. The r-NSGSO integrates the non-dominated sorting...
This paper introduces the use of the Swarm Variant of the Mean-Variance Mapping Optimization (MVMO-S) to solving the multi-scenario problem of the optimal placement and coordinated tuning of power system damping controllers (POCDCs). The proposed solution is tested using the classical IEEE 39-bus test system, New England test system. This papers includes performance comparisons with other emerging...
This paper focuses on implementing a dimensional Q-learning (DQL) for solving reactive power optimization with discrete control variables. The proposed algorithm applies the traditional Q-learning to search the feasible region dimensionally, so that the memory amount of each agent can be largely reduced. Meanwhile, the safety margin of voltage amplitude and reactive power output of generators are...
The future electricity distribution networks employ small-scale Distributed Generation (DG) units due to their numerous advantages. This paper sets out to find the best location for placing a DG unit so as to optimize certain parameters of interest. We formulate the issue of finding the most suitable place for a DG unit using Multi Criteria Decision Analysis (MCDA). In addition to discussing a new...
This paper presents a novel fault diagnosis model for oil-immersed power transformers based on dissolved gas analysis. The model is rooted on the theories of rough set and support vector machine. A fitness function based on attribute dependence is developed to identify fault features to improve classification accuracy of transformer fault samples by using Genetic Algorithm. To get improved classification...
In this paper, a new control strategy is proposed for PV based DC grid system with battery and supercapacitor as a hybrid energy storage system (HESS). To complement the supply demand mismatches in a PV energy based system a hybrid energy storage system consisting of battery and supercapacitor (SC) is generally used. The traditional control approach for HESS uses the high/low pass filter (HPF/LPF)...
Due to the growing share of distributed generation and electric vehicles in low and medium voltage networks, voltage regulation in distribution grids becomes inevitable. The use of tap changers is one solution favored by many network operators. This paper discusses changing requirements for tap changer control and recent developments in this field. In particular a new tap changer controller approach...
This paper presents solar irradiance forecasting in Mae Sariang, Mae Hongson Province, Thailand which has a solar power plant. This solar power plan is a photovoltaic (PV) with capacity power output at 4 MW. However, the adoption of solar irradiance as a power source on a global scale has not been uniform, due to by meteorological conditions, which cause the fluctuations and inconsistencies in PV...
An intermittent nature of the solar generation affects the micro-grid system noticeably when the micro-grid is disconnected from the power system through a fault, etc., and islanding operation is compulsory forced. So as to prevent anticipated problems, batteries are sometimes used for compensating surplus and shortage of the PV power output fluctuation. Two kinds of battery connections have been...
This paper presents an optimal day ahead schedule for a smart distribution network (SDN) using Electric vehicles (EVs) as one of the distributed energy resource (DER) in accordance with the variation in power market price. To avoid the adverse effect of massive EV integration on SDN, a coordinated charging/discharging strategy is worked out. Thus, the main objective is to minimize the hourly operational...
This paper presents a directional protection scheme for transmission lines based on directional comparison of the non-period current, which is estimated by a second-order differential algorithm. When the directions of non-periodic current at both sides are the same, the fault is discriminated as internal fault. When the directions are opposite, the fault is discriminated as external fault. A variety...
With the increasing penetration of distributed generation (DG) systems based on renewable energies into the power grid, the fault ride-through capability of them is stressed by recent grid codes. Aiming to adapting this requirement, this paper proposes a voltage sensorless predictive direct power control (PDPC) for the grid-interactive DC/AC converter utilized in DG systems. In order to realize a...
Due to the power peak load shifting, flexible load has considerable schedulable potential and could effectively improve the active distribution network (ADN) operation. After analyzing the scheduling mode and response characteristic of two typical flexible loads, this paper proposed a model for multiperiod service restoration in ADN with flexible load participated. On the basis of flexible load interruption...
False data injection attacks (FDIAs) have been introduced as a critical class of cyber attacks against smart grid's monitoring system. These attacks aim to compromise the reading of grid sensors and phasor measurement units. It was shown that FDIAs can pass the traditional bad data detection. Furthermore, to perform an FDIA, the attacker need to acknowledge the power grid topology and transmission-line...
At present more number of renewable generation units are being integrated to power system at distribution level. With the increased energy penetration, reverse in conventional power flow direction and different type of integrated renewable energy, existing over current based distribution protection philosophies needs to be enhanced. This paper presents protection scheme for inverter interfaced distribution...
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.