Amount Of Power Research Articles

Design and Testing of a Multi-port Sustainable DC Fast-charging System for Electric Vehicles

In this era of electrified transportation, inadequate fast-charging infrastructure and limited driving ranges in vehicles due to current energy storage technology remain bottlenecks in motivating consumers to rapidly shift to these electrified vehicles. Mass integration of these vehicles into the grid in the future would result in huge stress on the existing grid in terms of quantity and quality of power consumed. Understanding these issues in detail, this article exclusively discusses the design, development, and comprehensive testing of a multi-port sustainable fast-charging station involving solar photovoltaic, an in-house battery electric vehicle, the utility grid, multiple power electronic converters, and proper control under various modes of operation of the charging station. Such a charging station would enable quick and conventional charging with a lower power level through sustainable power, if available, hence reducing the impact on the grid and the energy cost of system operation.

M , the conservative power quantity based on the flow of energy

The reactive power in non-sinusoidal circuits is determined here from an energy analysis instead of using the non-sinusoidal apparent power S. In the first of the two energy analyses, circuits previously examined by the currents’ physical components power theory are re-examined using the principle of conservation of energy, the balance principle of the reactive power and the concept of reactive power compensation. This energy analysis yields a reactive power value substantiated by the aforementioned principles and power theory but it also suggests a value of S that differs from its traditional definition. The energy analysis performed with the circuit analysis technique based on geometric algebra, its GN domain power theory and M , a conservative power quantity based on the flow of energy, confirms the reactive power value attained in the former analysis. More importantly, M clarifies three intriguing issues about S: its value, its physical significance and whether this quantity can lead to erroneous conclusions. These, and previous results, demonstrate that the reactive power should be assessed on the energy flow but a multidimensional mathematical framework is needed to better understand energy flow in non-sinusoidal circuits.

Impact of dynamic and static fast inductive charging of electric vehicles on the distribution network

Fast inductive charging technologies allow the exchange of high power quantities (>20kW) between an Electric Vehicle and the electrical grid in contactless way. This demand can significantly modify the load profile of a distribution network and affect its operation and planning. Thus, it is necessary to quantify the grid impact of a network of fast inductive chargers and define the maximum allowable deployment level which does not violate the technical constraints of the network. This paper introduces a methodology for grid impact analysis of fast inductive charging technologies into distribution networks. The proposed methodology is implemented in a realistic model of a Greek MV distribution feeder providing indicative qualitative and quantitative results.

Effective electric power quantities and the sequence reference frame: A comparison study

More recently, unbalanced and distorted electric three phase quantities have been analyzed in the sequence reference frame, successively, by two elegant decomposition techniques referred to Girgis and Langella. Some comparisons regarding the matrices structures of the two methods have been drawn out in the Langella work. The latter also, makes it possible to evaluate the quantities defined in the IEEE Standard 1459-2010 by means of harmonic sequence components. Some previous author's works have focused on the Girgis method in which they analyzed the harmonic resonance phenomena and evaluated the quantities defined in the IEEE Standard 1459-2010 in the sequence reference frame. In the present work, the authors follow up with the Langella method and they present more explicit sequence effective electric quantities based on the two methods. Some substantial comparisons between the aforementioned works are presented as well.

Accurate CPC Power Analysis under Extreme EAF's Distortion Conditions

Electric Arc Furnaces (EAF) are huge energy consumer. However due a limited power calculation the maximum electrical efficiency is not obtained. Most of the applications in market report the usage of non valid power quantities in EAF power control system. Because the extreme distortion conditions of power phenomena produced by the nonlinearity of the load in the EAF, the implementation of Current's Physical Components (CPC) power theory has the potential of describing more accurate the physical load conditions and the electric power phenomenon during the Heat Process. Each one of the current components proposed by CPC offer useful information of the load condition, and give indicators which can be useful as stability indicators of the process for a better identification of the EAF stage.

Absorbed power distribution in the whole-body system of a tractor operator

Many people are exposed to vibration (WBV) in their occupational lives. The biodynamic responses of the human body in sitting conditions have been widely measured under whole-body vibration (WBV). The measures are most often expressed in terms of force-motion relations at the driving-point, namely, mechanical impedance, apparent mass and absorbed power, and flow of vibration through the body, such as seat-to-head and body segments vibration transmissibility. The absorbed power is a measure of the energy absorbed by the subject due to the external forces applied to the system. The body behaves like a vibrating physical system with distributed energy-storage elements (masses, springs) and energy-dissipation elements (dampers). The total quantity of power can be divided into 2 components - one real and one imaginary. The real component reflects the energy-absorbing part of the system, due to the transformation of friction into heat within the tissues. The imaginary component reflects the energy-storing part of the system which does not consume any vibration energy. The seated human is modeled as a series 4-DOF dynamic models. After introduction of the excitation, the response in particular segments of the model can be analyzed. As an example, the vibration power dissipated in an operator's body segments has been determined as a function of the agricultural combination operating speed 1.4 - 2.75 ms(-1). The concept of absorbed power as a measurement for evaluation of WBV exposure opens a new area for research. The important character of absorbed power is that it has physical significance and therefore can be measured as well as computed analytically. The absorbed power relates to dissipation of energy attributed to relative motions of the visco-elastic tissues, muscles and skeletal system, which under prolonged exposures could lead to physical damage in the musculoskeletal system. A structural model of the human operator allows determination of the dynamic characteristics of the model, and study of the energy flow between the elements of the model.

Adaptable Regression Method for Ensemble Consensus Forecasting

Accurate weather forecasts enhance sustainability by facilitating decision making across a broad range of endeavors including public safety, transportation, energy generation and management, retail logistics, emergency preparedness, and many others. This paper presents a method for combining multiple scalar forecasts to obtain deterministic predictions that are generally more accurate than any of the constituents. Exponentially-weighted forecast bias estimates and error covariance matrices are formed at observation sites, aggregated spatially and temporally, and used to formulate a constrained, regularized least squares regression problem that may be solved using quadratic programming. The model is re-trained when new observations arrive, updating the forecast bias estimates and consensus combination weights to adapt to weather regime and input forecast model changes. The algorithm is illustrated for 0-72 hour temperature forecasts at over 1200 sites in the contiguous U.S. based on a 22-member forecast ensemble, and its performance over multiple seasons is compared to a state-of-the-art ensemble-based forecasting system. In addition to weather forecasts, this approach to consensus may be useful for ensemble predictions of climate, wind energy, solar power, energy demand, and numerous other quantities.

结构量计算机——三值光学计算机的应用特点

In this paper, a novel technology for processing simple data via the hardware of a ternary optical (TOC) is investigated, and the natural sources of this powerful processing ability-massive quantity of data bits of the ternary photo-electronic processor, reconstruction bit by bit, and carry-free adder-are described. It is also discussed that how to use these characteristics to reconstruct a ternary optical processor into a composite one with many data bits and several different functions. Furthermore, this paper details how to apply this kind of composite processor to process vast amounts of different types of data in the hardware within one operation instruction. Apparently, when a TOC is applied to process data, which is composed of different types of simple data, only one instruction is needed. Thus, its overwhelming superiority is revealed. We call this kind of a structured data computer for its application features. At the beginning of this paper, a technique outline applying a TOC to process simple data is detailed, which includes the SZG file format, a method for generating the SZG file automatically, and the extension for advanced programming languages. Next, an example is given of processing data with four components of different types through the data computer. In conclusion, the strong capacity of the TOC for processing data is exhibited by analyzing the computational process of 1000 pairs of data.

Experimental Study on Performance of Wave Energy Converter System with Counterweight

In order to convert wave energy into large quantities of high-efficiency power, it is necessary to study the optimal converter system appropriate for the environment of a specific open ocean area. A wave energy converter system with a counterweight converts the translation energy induced from the heave motion of a buoy into rotary energy. This experimental study evaluated the primary energy conversion efficiency of the system, which was installed on an ocean generating basin with a power take-off system. Moreover, this study analyzed the energy conversion performance according to the weight condition of the buoy, counter-weight, and flywheel by changing the load torque and wave period. Therefore, these results could be useful as basic data such as for the optimal design of a wave energy converter with a counterweight and improved energy conversion efficiency.

EVALUATING DEGREE OF ACTIVE POWER LOSSES REDUCTION IN THE ELECTRIC POWER LINES WITH REACTIVE POWER COMPENSATION

The paper considers evaluation procedure for the degree of active power losses reduction in the power transmission lines under 1 kV and 6–10 kV of the systems of electric power supply of industrial enterprises with compensating installations mounted at the side of the customer. The capacitor installations conform to the applied voltage level and factor in dielectric losses in the capacitors. The voltage at the compensating device terminal changes from 0.95 to 1.05 of the capacitors nominal voltage. The study did not account for reactive power losses in the line, nor did it for its charge capacity, conditioned by relative shortness of the cable lines generally operating in the mains of industrial enterprises. For this reason, the quantities of reactive power being consumed and generated by the transmission line are negligible and do not significantly affect the reactive power flux. The researchers obtain functional relations that allow estimating the degree of power loss reduction in the transmission line factoring in its explicit initial data. They perform mathematical analysis of the obtained functional relations and study the function by means of derivatives. The function extremum points are found as well as the intervals of its increment and decrement. A graphical research of the obtained functional relation is performed. It is ascertained that reduction of the active power losses is contingent on the line and the capacitor-installation engineering factors, the electrical energy consumer reactive load value as well as the voltage applied to the capacitor installation. The functional relations presented in the article can be employed in scoping calculation necessary for decision making on the reactive power compensation in systems of the industrial facilities electric power supply. Their account will allow a more accurate estimate of technical and economic effect of the capacitor bank installation in the electrical mains under 1 kV and 6–10 kV.

Effective supervisory controllers designed for optimal energy management in permanent magnet synchronous generator wind turbine with battery storage

Optimal control of large-scale wind turbine has become a critical issue for the development of renewable energy systems and their integration into the power grid to provide reliable, secure, and efficient electricity. In this article, a new supervisory control system for the optimal management and robust operation of a wind turbine generator and a battery energy storage system is presented. The proposed coordinated controller can mitigate both active and reactive power disturbances due to the intermittency of wind speed and load change. Moreover, the control strategy ensures the maximum power extraction capability of direct-drive wind turbine. This supervisory controller is made up of three subsystems. The first one is used to track the maximum power point for variable wind speeds; the control algorithm employs a fuzzy logic controller and a second-order sliding mode controller to effectively meet this target. The task of the second one is to maintain the required DC-link voltage level. This is achieved by controlling the bidirectional power flow in the storage batteries using DC–DC converter. Whereas in the last, a second-order sliding mode controller is investigated to achieve smooth regulation of grid active and reactive power quantities, which provides better results in terms of attenuation of the harmonics present in the grid courant compared with the conventional first-order sliding mode controller. Extensive simulation studies under different conditions of wind speed are carried out in MATLAB/Simulink, and the results confirm the effectiveness of the new supervisory control system.

단상 에너지 측정용 IC 구현

This paper presents a single-phase energy measurement IC to measure electric power quantities. The entire IC includes two programmable gain amplifiers (PGAs), two ∑∆ modulators, a reference circuit, a low-dropout (LDO) regulator, a temperature sensor, a filter unit, a computation engine, a calibration control unit, registers, and an external interface block. The proposed energy measurement IC is fabricated with 0.18-μm CMOS technology and housed in a 32-pin quad-flat no-leads (QFN) package. It operates at a clock speed of 4,096 kHz and consumes 10 mW in 3.3 V supply.

Prediction of electric power consumption by nuclear power plants for covering plant needs using data mining methods

In the process of its operation nuclear power plant consumes significant amounts of electric power – the so-called power consumption for coverage of plant needs. According to the practice existing in Russia, nuclear power plant must order in advance from the power supply grid operator the required quantity of electric power, while deviations of factual electric power consumption from the forecasted value one way or another entail payment of certain financial penalties. Because of this reason accuracy of forecasting the electric power consumption for the nearest coming period attains special importance. Application of different methods of data analysis for forecasting electric power consumption by NPPs using factual data is addressed and comparison of these methods between each other, as well as with those currently in application by NPPs is made. As the result, a method is suggested for forecasting NPP power consumption for coverage of plant needs with significantly higher accuracy of forecasting.

Optimisation of micro-perforated cylindrical silencers in linear and nonlinear regimes

This paper describes analytical and experimental studies conducted to understand the potential of lightweight non-fibrous alternatives to dissipative mufflers for in-duct noise control problems, especially under high sound pressure levels (SPLs) and in the low frequency domain. The cost-efficient multi-modal propagation method has been extended to predict nonlinear effects in the dissipation and the transmission loss (TL) of micro-perforated cylindrical liners with sub-millimetric holes diameter. A validation experiment was performed in a standing wave tube to measure the power dissipated and transmitted by a nonlocally reacting liner under moderate and high SPLs. Although nonlinear effects significantly reduce the dissipation and TL around the liner maximum damping frequency, these power quantities may be enhanced below the half-bandwidth resonance. An optimal value of the in-hole peak particle velocity has been found that maximizes the TL of locally reacting liners at low frequencies. Optimisation studies based on dissipation or TL maximization showed the sensitivity of the liner constituting parameters to variations in the design target range such as the center frequency, the levels of acoustic excitation and the nature of the surface impedance (locally or nonlocally reacting). An analysis is proposed of the deviation observed at low frequencies between the optimum impedance of the locally reacting liner under moderate SPLs and Cremer׳s optimum impedances.

Enhancing high performance of emergency unit by improving the management emergency team system of the Plateau State Specialist Hospital Nigeria

There are challenges with the management of the emergency units of healthcare organizations in Nigeria; these have been observed from the high mortality rate, high level of left before examination (LBE) of the patients, low response time to acute care patients and poor turnaround time by the healthcare givers to address emergency situations. Therefore there is an urgent need to address the situation and solve the problems best ways possible by improving the management emergency team (MET) system of the healthcare organization. These was achieved by quantitative methodology application through the distribution of questionnaires, interviews and personal observation of the situation, hence improving the quality and quantity of the man power which is the human resources with qualified and well trained medical personnel, adding also to the management emergency team are police protocol officers who can give police report immediately for unconscious accident victims on arrival for emergency treatment, eliminating need for unavailable consent form before treatment, adding intensive training programs for MET system, emergency hotlines and ambulance assistance for patients, adequate supplies of oxygen and facilities that are up-to-date for the emergency unit. These solutions have increased the stability of the emergency unit, lower mortality rate, increased the efficiency of the team, improved response time, higher survival rate, improving the staff efficiency and effectiveness, after which it is observed that the emergency unit is on high-performance level, with good survey feedback by patients and their relatives.

Tidal power: A different perspective

Kepler Energy is taking a different approach to tidal power, applying a design that can be used in benign sea conditions in a location closer to end-demand and which could generate utility-scale quantities of power, as Peter Dixon explains.

High strain-rate magnetoelasticity in Galfenol

This paper presents the experimental measurements of a highly magnetoelastic material (Galfenol) under impact loading. A Split-Hopkinson Pressure Bar was used to generate compressive stress up to 275 MPa at strain rates of either 20/s or 33/s while measuring the stress-strain response and change in magnetic flux density due to magnetoelastic coupling. The average Young's modulus (44.85 GPa) was invariant to strain rate, with instantaneous stiffness ranging from 25 to 55 GPa. A lumped parameters model simulated the measured pickup coil voltages in response to an applied stress pulse. Fitting the model to the experimental data provided the average piezomagnetic coefficient and relative permeability as functions of field strength. The model suggests magnetoelastic coupling is primarily insensitive to strain rates as high as 33/s. Additionally, the lumped parameters model was used to investigate magnetoelastic transducers as potential pulsed power sources. Results show that Galfenol can generate large quantities of instantaneous power (80 MW/m3), comparable to explosively driven ferromagnetic pulse generators (500 MW/m3). However, this process is much more efficient and can be cyclically carried out in the linear elastic range of the material, in stark contrast with explosively driven pulsed power generators.

Method for Selecting Quantity and Power of Diesel Generators

In this paper a method of optimization of the quantity of diesel power generating units according to the schedule of electric loads based on the undersupply expectation and the power supply interruption, emergency and planned stops of diesel generators is proposed.

Single-Phase Energy Metering Chip with Built-in Calibration Function

This paper presents a single-phase energy metering chip with built-in calibration function to measure electric power quantities. The entire chip consists of an analog front end, a filter block, a computation engine, a calibration engine, and an external interface block. The key design issues are how to reduce the implementation costs of the computation engine from repeatedly used arithmetic operations and how to simplify calibration procedure and reduce calibration time. The proposed energy metering chip simplifies the computation engine using time-division multiplexed arithmetic units. It also provides a simple and fast calibration scheme by using integrated digital calibration functionality. The chip is fabricated with 0.18-μm six-layer metal CMOS process and housed in a 32-pin quad-flat no-leads (QFN) package. It operates at a clock speed of 4096 kHz and consumes 9.84 mW in 3.3 V supply.

Study of spin-ordering and spin-reorientation transitions in hexagonal manganites through Raman spectroscopy.

Spin-wave (magnon) scattering, when clearly observed by Raman spectroscopy, can be simple and powerful for studying magnetic phase transitions. In this paper, we present how to observe magnon scattering clearly by Raman spectroscopy, then apply the Raman method to study spin-ordering and spin-reorientation transitions of hexagonal manganite single crystal and thin films and compare directly with the results of magnetization measurements. Our results show that by choosing strong resonance condition and appropriate polarization configuration, magnon scattering can be clearly observed, and the temperature dependence of magnon scattering can be simple and powerful quantity for investigating spin-ordering as well as spin-reorientation transitions. Especially, the Raman method would be very helpful for investigating the weak spin-reorientation transitions by selectively probing the magnons in the Mn3+ sublattices, while leaving out the strong effects of paramagnetic moments of the rare earth ions.