The influence of distortions in voltage and current waveforms on state-of-the-art single-phase and three-phase power meters, commonly used in the utility power system of the Slovak Republic, was studied. A computer-controlled test system capable of generating nonsinusoidal voltages and currents and a reference power quality analyzer were used for this purpose. The results of the experiments on several

A transmission line fault classification scheme is proposed in this article using Poincaré-based correlation analysis of three-phase fault currents. The method segments each fault signal into two equal time-split components and computes correlation coefficient between these two time-split signals. The fault current signals of the directly affected line(s) observe an abrupt monotonic rise, compared

The basic prerequisites for the correct operation of the classic on-load tap-changing voltage control (CVC) are that the distribution network (DN) is passive. However, by installing distributed generators (DGs), today's DNs become increasingly active. Consequently, by measuring only the current and voltage magnitudes at the on-load tap-changing transformer secondary side, its automatic voltage regulator

In order to accommodate the uncertainty and variability of wind power, this paper proposes a scenario-based probabilistic model to assess the impact of intermittent wind power-based Renewable Energy Resources (RES) on the Transmission Network Expansion Planning (TNEP). The objectives comprise the evaluation of impacts considering the wind power penetration into connected and unconnected buses, as well

In lightning discharge, the grounding systems' transient behavior is influenced by frequency-dependent effects. These effects are related to complex phenomena arising from the fast rise time of the impulse current. In this paper, a new frequency-dependent (FD) model of grounding systems (GSs) is presented that can be deployed in time-domain analysis. The proposed wideband modeling considers the frequency

The state of charge (SOC) estimation is the core of any battery management system (BMS). However, the accurate SOC estimation is always a challenging task because it cannot be measured directly with sensors. An adaptive robust unscented Kalman filter (ARUKF) with recursive least square (RLS) is proposed to improve the robustness and accuracy of SOC estimation in this paper. In the proposed method,

This paper develops a Kalman filter-based method to estimate the magnitude and phases of currents and voltages of a single-phase transmission line. Unlike common-place practices, in which phasors are estimated by using Fourier-based or least squares methods, the standard Kalman filter algorithm is used. We represent the transmission line by using a steady-state model in which the phasors of voltages

In this study, approximate derivative (AD) signal processing method using synchronous voltages data, based on the traveling wave theory, was developed to determine fault locations in transmission lines. The first aerial mode voltage signals were obtained by applying the Clarke transformation to the voltage signals that occur after a short circuit fault. Then, by taking the first AD of the aerial mode

This paper presents a systematic investigation about the extremely low-frequency magnetic fields generated in the vicinity of high voltage overhead power transmission lines constituting the Algerian national electricity power transmission grid. The influences of loading current on the magnetic field as well as the variation of tower configuration and conductor section are investigated. Simulations

Modern power sector requires grid observability under all scenarios for its ideal functioning. This enforces the operator to incorporate state estimation solutions based on a priori measurements to deduce the corresponding operating states of the grid. The key principle for such aforementioned algorithms lies on an occurrence of an over determined class of system having an ample redundancy in the measurements

This paper studies the effect of permanent magnet shape on the performance and efficiency of coreless axial flux permanent magnet synchronous generator (AFPMSG) for low-speed applications. The objective of this study was to come up with an optimal magnet shape among the studied cases that will lead to the highest value of induced EMF, eventually leading to the better output power of the machine. According

In this study, an improved Adaptive Fast Terminal Synergetic Controller (AFTSC) using Dual Radial Basis Function (RBF) Neural Networks (NNs) for output voltage control of an uncertain DC/DC step-down converters is proposed. Using the considered AFTSC, the with new manifold proposed here enables the DC/DC step-down converter’s state variables to track the preferred reference voltage in presence of disturbances

The smart transformer (ST) is a key component for the continuously evolving smart grid applications. It is a very promising alternative to the conventional transformer owing to its numerous advantages. For instance, it allows instantaneous voltage regulation, bidirectional power control as well as the integration of renewable energy systems and electric vehicles into the distribution grid. Among the

Power swings appear as a result of sudden addition or removal of heavy loads, switching, cutoff of a parallel line, and reclosing. These swings can affect the protective zones of distance relays, causing them to malfunction and erroneously cut off healthy lines from the grid. This paper proposes a new solution for detecting power swings and preventing this malfunction based on the variance of data

Double-turbine systems offer a higher capability of wind energy conversion compared to single-turbine systems. Therefore, in order to improve the performance of double-turbine systems and eliminate mechanical gearbox systems by utilizing the direct-drive concept, a new direct-drive generator design is required. In this paper, the structure of a novel spoke-type permanent magnet induction generator

The control algorithm of a DSTATCOM majorly influences its function. The key role of a phase locked loop (PLL) as a fundamental extractor in the control algorithm is inevitable. It is used to extract the information of the fundamental like phase angle, frequency and amplitude from the distorted voltage/current signal. According to the information collected, the performance of the control algorithm

High scale integration of renewable energies has led power system towards a new set of challenges that have increased the complexity of cost optimization problem. Moreover, forecast errors in the prediction of wind, PV and load affect the accuracy of optimization. Therefore, cumulants and Gram–Charlier method have been proposed for solving probabilistic load flow (PLF)-based optimal transmission switching

An improved high voltage boost Z-source inverter topology is proposed to improve voltage boost ability. Compared to the conventional Z-source inverter, it can produce very high voltage boost with a short shoot-through duty ratio, the voltage stress on Z-source capacitors and inverter-bridge is greatly reduced, and has inherent limitation to inrush current at startup. The addition of a input capacitor

Parasitic extraction is a powerful tool in the design process of electromechanical devices, specifically as part of workflows that check electromagnetic compatibility. A novel scheme to extract impedances from CAD device models, suitable for a finite element implementation, is derived from Maxwell’s equations in differential form. It provides a foundation for parasitic extraction across a broad frequency

This paper presents a simple turn-on and turn-off angles adjustment method to increase the efficiency of small-size switched reluctance motor (SRM) in wide speed and torque range. The simplicity of the control algorithms allows building a variable speed drive without a high-performance microcontroller and FPGA or ASIC. The firing angles calculation uses a second-order polynomial and look-up table.

This study quantified the impact of future battery electric vehicle (EV) charging on the least-cost electricity generation portfolio in South Africa (RSA). This was done by performing a capacity expansion optimization of the generation fleet for the year 2040. It was assumed that there would be 2.8 million EVs by 2040, informed by global estimates. Two EV charging scenarios were tested, one using an

Vibration and noise are inseparable. Torque ripple is one of the major sources of acoustic noise in the steady operation of hybrid stepper motor. Identifying the effects of these sources are important for in motor drive research. The paper analyses the relationship between the acoustic noise frequency and harmonic current in 3-phase hybrid stepper motor. The results show that the micro-stepping drive

This paper proposes a fault diagnosis method for electrical machine drive system by using backpropagation neural network (BPNN) optimized by chaotic adaptive gravity search algorithm (GSA) and particle swarm optimization (PSO) algorithm. In this method, an adaptive gravitational constant factor based on iteration times and chaotic mapping is introduced to balance the global search ability and local

In this paper, a new non-isolated DC-DC converter is proposed. This converter topology is a high step-up boost converter with an extended voltage multiplier cell and a Cuk converter as a series output module. Compared to its high step-up counterpart, the proposed converter has a higher voltage gain. In this converter, an active clamp circuit is used to absorb the energy of leakage inductor, therefore

The sensitive electronic devices can be damaged or malfunction due to power disturbances in an electrical system. A fast and accurate detection of power disturbances in the system is the key to take appropriate corrective measures. This paper presents an innovative algorithm for fast and accurate detection of power disturbance. The algorithm is based on four major steps; segmentation of acquired signal

This paper evaluates the performance of two arrangements of interphase transformers using a new AC–DC 48-pulse converter (SC-48P) for industrial applications with high currents in the order of hundreds of kiloamperes, so that consumers and other loads connected to the SC-48P electrical grid are not affected by the harmful effects caused by harmonic currents injected into the grid by converters. The

Severe pollution environment over the Israel Electric (IECo) Power Grid is created by synergy between Saharan dust and sea-salt aerosols (SSA) originated from the Mediterranean Sea. In the presence of high air humidity, the resultant pollution stress remains one of the major factors affecting operational reliability of ceramic insulators in the IECo Network. In respect with the severe polluted conditions

Under the traditional hybrid modulation strategy, the output powers of the hybrid cascaded H-bridge inverter are not balanced between the cascaded units. With a hybrid cascaded H-bridge 13-level inverter with a DC side voltage ratio of 1:1:1:3 (referred to as III-inverter in the paper) as the research object, a hybrid modulation power equalization strategy based on carrier rotation is proposed. Under

In this paper, a stochastic transmission expansion planning (TEP) in the presence of wind farms under uncertain load and wind source conditions when reliability and N-1 contingency is taken into consideration is proposed. The main aim of the suggested TEP is to minimize the total planning cost while satisfying techno-economic constraints. In this paper, reliability cost is also incorporated as the

This paper presents a motor design which can operate directly with a low-voltage output photovoltaic panels or batteries. A high-efficiency synchronous reluctance motor which can operate directly at low voltage level without a boost converter was designed in this study. The motor was optimized for maximum torque and minimum torque ripple by using the multi-objective genetic algorithm. A robust, durable

This paper presents an improved magnetic equivalent circuit (MEC) method for modeling linear permanent-magnet synchronous motors (LPMSMs) with adjustable accuracy. The performance of machine with different dimensions, poles and slot numbers can be studied by the proposed flexible MEC, where the core nonlinearity is fitted on the material B–H curve. End effect is modeled by considering two virtual zones

Volt/VAr/Demand control of consumer points in active distribution networks is a multidirectional function affected by the transmission, production, and network operations. Load tap changers and voltage regulators are the most common network elements for decreasing main fluctuations. However, the voltage changes performed by these network devices also affect the active and reactive consumptions at the

The present research focuses on the characteristics of a two-stage pseudo-spark switch (PSS). In this project, the pseudo-spark chamber contains three identical electrodes constructed from a stainless-steel material isolated by a glazed ceramic material used as an insulator, with 0.07 m in diameter and 0.003 m in thickness. A pseudo-spark switch of ~ 30 kV anode voltages, 24 kA with 5 ns current rise

The growth rate of electric vehicle sales is increasing every year, analytical companies provide optimistic forecasts for the number of electric vehicles on the roads in the future, and regulators are changing rates for future growth. In this regard, the full implementation of the concept of smart networks, which could facilitate the transition of old networks to a new reality, is becoming increasingly

In this work, a high performance sensor-less V/f control technique for surface permanent magnet synchronous motors is developed by realizing the control in voltage vector plane. To achieve this, the torque expression is derived in voltage vector plane. Thereafter, the equation is modified considering d-axis voltage as zero. It establishes a direct relationship of torque with q-axis voltage and amplitude

Lithium-ion batteries are electrochemical storage devices that occupy an important place today in the field of renewable energy applications. However, challenging requirements of lithium-iron-phosphate LiFePO4 (LFP) batteries in terms of performances, safety and lifetime must to be met for increase their integrations in these applications. It is important to identify the origins and symptoms of battery

This paper presents a new optimized winding and core design for improved performance of an induction machine. The performance improvement is attained by space harmonic reduction in the winding magnetomotive force (MMF). In the proposed design, the new conductor distribution of the winding and its slot positions are obtained by solving an optimization problem which maximizes the fundamental component

This paper analyzes the operation and characterizes the performance of a three-phase three-level (3-L) Sparse Neutral Point Clamped converter (SNPCC) for industrial variable speed drives (VSDs). The operating principle of the SNPCC, which advantageously employs a lower number of power transistors than a conventional 3-L inverter, is described in detail, focusing on the AC-side differential-mode and

Reliability in the supply of electricity depends on isolation from the electrical power system. Insulators are components that have the function of insulating and supporting the electrical grid. The design of electrical distribution network insulators can have a great influence on the distribution of the electric field over its surface. When there is a great intensity of electric field applied specifically

At present, research of cable fault diagnosis based on artificial intelligence mainly takes statistical characteristics as inputs, which means the appropriateness of statistical characteristic selection is directly related to the diagnosis accuracy and the identification results may have certain contingency. Further, most of these methods do not consider the correlation of signals in time. Therefore

XLPE material, which is widely used as a polymeric insulator in medium and high voltage applications, plays an active and important role in electricity transmission and distribution. The aging of XLPE materials due to various factors is inevitable. It is observed that fault and troubleshooting increase with the aging of materials. Wettability behavior is one of the fundamental surface properties of

The continuous proliferation of distributed generation is leading end users to look for new tools that help to design hybrid electrical energy systems (HEES). Thus, this work proposes a novel approach for optimal planning of HEES, which comprises the optimization of the type and capacity of distributed generation connected to the end user. The main objective is to minimize the project’s total cost

Modal analysis has been widely used for voltage stability assessment based on the sensitivities of reactive powers with respect to voltage magnitudes obtained from the traditional power flow Jacobian. It provides a relative measure of proximity to voltage instability and determines participation factors to find the critical areas of the system. However, in practice, the most probable state of the system

Charge trap characteristics of epoxy spacer insulating material due to surface flashover are important for improving the stable operation of GIS. In this work, magnesium oxide (MgO) filled epoxy nanocomposite material is proposed as the spacer material and its performance is compared with pure epoxy. The surface properties of spacer materials were altered using surface flashovers generated due to standard

The quality of electricity transmission and distribution strongly depends on the behavior of insulating systems. The presence of faults in the high voltage cable, generated during its manufacture or installation, can cause network perturbation ranging from simple partial discharge to the power line decommissioning by total electric discharge. The occurrence of gaseous cavities in the insulation of

Lithium-ion battery energy storage systems (Li-ion BESS), due to their capability in providing both active and reactive power services, act as a bridging technology for efficient implementation of active network management (ANM) schemes for land-based grid applications. Due to higher integration of intermittent renewable energy sources in the distribution system, transient instability may induce power

The control strategy is an essential element in the improvement of electric motor energy efficiency through flux adaptation, according to the operating conditions. Therefore, the goal of this paper is to present an energy-efficient field-oriented control structure for squirrel-cage induction motors (IM), improving their energy efficiency and taking into consideration the core loss effect. For this

A novel dynamic modeling methodology for meteorological sensitive load forecasting of smart grids is proposed by using Fisher information theory and online support vector regression (OSVR) technology to improve load prediction accuracy in this paper. According to the changes in the operating state of the smart grids and streaming data characteristics, the OSVR model is employed to implement accurate

A device, comprising a system of rod-plane electrodes with a horizontal axis, enveloping tubular glass barriers or vertical planes as well as supports for their attachment, has been made. The tubular barriers were coated with a thin layer of either superhydrophobic soot or hydrophobic silicone. The electrical performance of the tubular soot barrier has been determined experimentally based on its size

Energy storage systems have become inevitable components of a DC microgrid in terms of pacifying voltage/current fluctuations that are unavoidable due to the unpredictable, intermittent nature of renewable energy system and load. These fluctuations normally result in power quality issues in addition to stability issues. The transient pressure on the DC bus increases with an increase in distance between

Vehicles have become an integral part of the modern era, but unfortunately conventional vehicles consume non-renewable energy resources which have associated issue of air pollution. In addition to that, global warming and the shortage of fossil fuels have provided motivation to look for alternative to conventional vehicles. In the recent era, hybrid electric vehicle (HEV) is becoming popular due to

The paper proposes a new power flow model and calculation procedure for large-scale multi-phase (unbalanced) distribution networks with simultaneous phase interruptions. Differently from traditional linear models for calculations of networks with simultaneous short-circuits and phase interruptions, phase interruptions are treated in this paper much more realistically—as outages which are incorporated

This paper presents a generalized structure of a new three-phase multilevel inverter (MLI) which ensures better performance with the minimum number of components for different applications including DC power supply-based renewable energy sources. The proposed MLI topology is developed in the form of several basic blocks which are individually made of a DC voltage source and a semiconductor switch.

Electric motors are widely used in many industrial applications on account of stability, solidity and ease of use. Mechanical bearing faults have the highest statistical occurrence percentage among all of the motor fault types. Accurate and advance detection of the bearing faults is critical to avoid unpredicted breakdowns of electric motors. Through early detection of bearing faults, it would be possible

With the recent advancement in smart grid technology, real-time monitoring of grid is utmost essential. State estimation-based solutions provide a critical tool in monitoring and control of smart grids. Recently there has been an increased focus on false data injection attacks which can circumvent the traditional statistical bad data detection algorithm. Most of the research methodologies focus on

In a power system, the incurred transmission loss and the associated sensitivity factors are dependent on the selection of the slack bus and the dispatch. In this paper, a fast two-stage, hydro-thermal generation scheduling process, which is also inclusive of the system power loss, is proposed. A novel approach towards estimating power loss sensitivity factors is presented which is independent of the

The power loss estimation is a crucial step for power electronics design, especially for high-power-density systems. Many mathematical approaches are known for power loss estimation, but the system design time can be lowered significantly if a simulation approach is used. This paper discusses the MATLAB-based simulation method for estimating power losses in the three-phase VSI. This simulation is using

Aimed at different demands of power of multiple receiver loads in multiple-input multiple-output wireless power transfer (MIMO-WPT) system, in the paper, a method of calculating the excitation source at the transmitter by general circuit model is put forward to realize the power allocation of the receiver loads. First, the magnetic coupling resonance (MCR) MIMO-WPT system is made to be equivalent to

This paper presents the development of a multi-input multi-output bi-directional power converter (MIMO-BDPC) with a digital pulse-width modulation (DPWM) controller for solar photovoltaic (SVP) application. The converter is operated in three modes such as buck, boost, and inverter. The converter uses a minimum number of active components and the DPWM controller controls the switching frequency or pulse