Accurate electric energy(EE)measurements and billing estimations in a power system necessitate the development of an energy flow distribution model.This paper summarizes the results of investigations on a new problem ...Accurate electric energy(EE)measurements and billing estimations in a power system necessitate the development of an energy flow distribution model.This paper summarizes the results of investigations on a new problem related to the determination of EE flow in a power system over time intervals ranging from minutes to years.The problem is referred to as the energy flow problem(EFP).Generally,the grid state and topology may fluctuate over time.An attempt to use instantaneous(not integral)power values obtained from telemetry to solve classical electrical engineering equations leads to significant modeling errors,particularly with topology changes.A promoted EFP model may be suitable in the presence of such topological and state changes.Herein,EE flows are determined using state estimation approaches based on direct EE measurement data in Watt-hours(Volt-ampere reactive-hours)provided by electricity meters.The EFP solution is essential for a broad set of applications,including meter data validation,zero unbalance EE billing,and nontechnical EE loss check.展开更多
Aiming at the shortcomings of the existing electric energy metering method,combining with the harmonic responsibility analysis model based on the reference impedance method and the idea of apparent power decomposition...Aiming at the shortcomings of the existing electric energy metering method,combining with the harmonic responsibility analysis model based on the reference impedance method and the idea of apparent power decomposition in IEEE Std 1459-2010 standard,two new metering indicators—billing active power and billing power factor are defined.A new electric energy metering method is proposed and its specific implementation steps are given.The simulation model is built in Matlab/Simulink,and three different examples are set up.Using the simulation data,the various metering indicators need to be examined by the existing electric energy metering method and the new electric energy metering method are calculated.The calculation results show that the new electric energy metering method not only overcomes the shortcomings of the existing electric energy metering method,but also is very easy to be popularized and applied.展开更多
Currently a large effort is being done with the intention to educate people about how much energy each electrical appliance uses in their houses, since this knowledge is the fundamental basis of energy efficiency prog...Currently a large effort is being done with the intention to educate people about how much energy each electrical appliance uses in their houses, since this knowledge is the fundamental basis of energy efficiency programs that can be managed by the household owners. This paper presents a simple yet functional non-intrusive method for electric power measurement that can be applied in energy efficiency programs, in order to provide a better knowledge of the energy consumption of the appliances in a home.展开更多
This article puts forward an automatic recognition algorithm of electric energy meter lead seals： firstly, the image will be histogram equalization, smoothing, binaryzation pretreatment, then according to the image c...This article puts forward an automatic recognition algorithm of electric energy meter lead seals： firstly, the image will be histogram equalization, smoothing, binaryzation pretreatment, then according to the image characteristics of text changes, the system can quickly and accurately segment image from complex background, finally the system extract different dimension and the feature of English and Arabia using digital projection transform coefficient method and to identify the corresponding number by BP neural network, solves the problem of automatic recognition of electric energy meter lead sealing.展开更多
Aiming at the problem of large energy consumption in hydraulic control system with large load and variable working conditions,based on the multi-level pressure switching control system(MPSCS),a multi-level pressure sw...Aiming at the problem of large energy consumption in hydraulic control system with large load and variable working conditions,based on the multi-level pressure switching control system(MPSCS),a multi-level pressure switching control system based on independent metering control is proposed combined with the independent metering control technology.The configuration principle of the system is given,the mathematical model of this system is established,and the control strategy of the system under 4 different working quadrants is put forward.Finally,the control performance and energy saving characteristics of the system are tested.The test results show that the switching of high and low pressure power supply has a certain effect on the response of step position and ramp position under impedance working condition.The displacement curves show slow climbing or abrupt change of ramp position,and the position accuracy is less than 1 mm.The multi-level pressure switching control system based on independent metering control can recover and store energy under the transcendence working conditions.The control accuracy is about 1 mm,and the energy recovery rate is about 70%~80%.展开更多
Purpose-For billing purposes,heavy-haul locomotives in Sweden are equipped with on-board energy meters,which can record several parameters,e.g.,used energy,regenerated energy,speed and position.Since there is a strong...Purpose-For billing purposes,heavy-haul locomotives in Sweden are equipped with on-board energy meters,which can record several parameters,e.g.,used energy,regenerated energy,speed and position.Since there is a strong demand for improving energy efficiency in Sweden,data from the energy meters can be used to obtain a better understanding of the detailed energy usage of heavy-haul trains and identify potential for future improvements.Design/methodology/approach-To monitor energy efficiency,the present study,therefore,develops key performance indicators(KPIs),which can be calculated with energy meter data to reflect the energy efficiency of heavy-haul trains in operation.Energy meter data of IORE class locomotives,hauling highly uniform 30-tonne axle load trains with 68 wagons,together with additional data sources,are analysed to identify significant parameters for describing driver influence on energy usage.Findings-Results show that driver behaviour varies significantly and has the single largest influence on energy usage.Furthermore,parametric studies are performed with help of simulation to identify the influence of different operational and rolling stock conditions,e.g.,axle loads and number of wagons,on energy usage.Originality/value-Based on the parametric studies,some operational parameters which have significant impact on energy efficiency are found and then the KPIs are derived.In the end,some possible measures for improving energy performance in heavy-haul operations are given.展开更多
Correction factors of both Rem-meters, the 10 inch diameter single-sphere Remmeter and the standard A-B Rem-meter, were estimated for measuring high energy neutron dose equivalent outside a concrete shielding wall and...Correction factors of both Rem-meters, the 10 inch diameter single-sphere Remmeter and the standard A-B Rem-meter, were estimated for measuring high energy neutron dose equivalent outside a concrete shielding wall and the effects that the emitted neutron spectra become remarkably "harder" penetrated through a concrete shielding wall, and the energy response of the Rem-meter were taken in account. The estimated results could be applied in the measurement of neutron dose equivalent for the intermediate energy heavy ion reactions to avoid the difficulty induced by the energy response of the Rem-meters.展开更多
智能电能表在复杂电网环境下的计量精度易受非线性误差影响。为提高其准确性,提出一种融合非线性自回归外生输入(nonlinear auto-regressive with exogenous inputs,NARX)模型与畸变功率的误差校正方法。利用NARX模型构建电能表的非线...智能电能表在复杂电网环境下的计量精度易受非线性误差影响。为提高其准确性,提出一种融合非线性自回归外生输入(nonlinear auto-regressive with exogenous inputs,NARX)模型与畸变功率的误差校正方法。利用NARX模型构建电能表的非线性误差模型,以捕捉其动态特性;从测量数据中分离基波与谐波电能,并计算谐波电能比差以量化谐波影响;引入畸变功率概念,构建以谐波电能比差和畸变功率为输入的误差校正模型,对非线性误差进行补偿。实验结果表明:经所提方法校正后,在不同谐波含量(5%、10%、20%)条件下,智能电能表的最大计量误差由校正前的2.4%、3.1%、10.3%均降至0.5%左右,同时非线性误差预测结果的拟合度得到了提升,有效提高了谐波环境下的计量精度。展开更多
Objective<span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">: Determine the Test reliability and the objective validity of ...Objective<span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">: Determine the Test reliability and the objective validity of the International Physical Activity Questionnaire (IPAQ). <span style="font-family:Verdana;font-size:12px;">Methods<span style="font-family:Verdana;">:<span style="font-family:Verdana;"> IPAQ was evaluated for test-retest reliability within 6<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">-<span style="font-size:10pt;font-family:;" "=""> <span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">8 days of its first administration. Criterion validity was tested comparing IPAQ data with those from an activity meter (Intelligent Device for Energy Expenditure and Activity, IDEEA). <span style="font-family:Verdana;font-size:12px;">Results<span style="font-family:Verdana;font-size:12px;">: The test-retest correlation (n = 71) for items of IPAQ ranged from r = 0.63 to r = 0.74 and w<span style="font-family:Verdana;">as <span style="font-family:Verdana;">r = 0.79 for the total weekly PA in MET*min per week. Average PA (in MET*min/week) measured with the IDEEA meter, decreased from normal (15<span style="font-family:Verdana;">,<span style="font-family:Verdana;">840), to 14<span style="font-family:Verdana;">,<span style="font-family:Verdana;">278 in overweight<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">(BMI<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">><span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">25-<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;"><<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">30) and further to 12<span style="font-family:Verdana;">,<span style="font-family:Verdana;">803 in obese subjects (>30. BMI). The weekly energy expenditure measured by IDEEA correlated significantly (r = 0<span style="font-family:Verdana;">.<span style="font-family:Verdana;">61,<span style="font-size:10pt;font-family:;" "=""> <span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">r<sup><span style="font-family:Verdana;font-size:12px;">2</sup><span style="font-family:Verdana;font-size:12px;"> = 0.38) with the IPAQ data, providing an objective criterion for validity of IPAQ. The mean values of weekly PA estimated from IPAQ (in MET*min/week) differed significantly in the high (15<span style="font-family:Verdana;">,<span style="font-family:Verdana;">690) vs. the low (11<span style="font-family:Verdana;">,<span style="font-family:Verdana;">398) activity groups but not between the moderate (12<span style="font-family:Verdana;">,<span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">056) compared to the low PA group. The IPAQ criteria used to categorize subjects as moderately active, erred by including too many low PA subjects. IDEEA measurements in sedentary subjects overestimated their energy expenditure. <span style="font-family:Verdana;font-size:12px;">Conclusions<span style="font-family:Verdana;font-size:12px;">: IPAQ can be reliably used to distinguish low and high PA groups and yields relatively low estimates (−<span style="font-family:Verdana;">18%) of weekly PA in these groups compared to those measured with the activity meter. Stricter criteria are needed to distinguish moderate from low PA groups. Overweight and obese subjects showed significantly lower levels of PA than normal BMI subjects.<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">IDEEA overestimates low levels of PA.展开更多
With the increasing demand for petroleum resources and environmental issues,new energy electric vehicles are increasingly being used.However,the large number of electric vehicles connected to the grid has brought new ...With the increasing demand for petroleum resources and environmental issues,new energy electric vehicles are increasingly being used.However,the large number of electric vehicles connected to the grid has brought new challenges to the operation of the grid.Firstly,A novel bidirectional interaction model is established based on modulation theory with nonlinear loads.Then,the electric energy measuring scheme of EVs for V2G is derived under the conditions of distorted power loads.The scheme is composed of fundamental electric energy,fundamental-distorted electric energy,distorted-fundamental electric energy and distorted electric energy.And the characteristics of each electric energy are analyzed.Finally,the correctness of the model and energy measurement method is verified by three simulation cases:the impact signals,the fluctuating signals,and the harmonic signals.展开更多
The quality of methods for determining energy transits on the tie lines （lines that connect two neighboring power system） can have significant impact on business activity of the TSOs （transmission system operators...The quality of methods for determining energy transits on the tie lines （lines that connect two neighboring power system） can have significant impact on business activity of the TSOs （transmission system operators）. Existing law regulation is not enough precise regarding definition of methods for metering energy transits （energy interchanged between neighboring TSOs）. This paper analyses disadvantages of method for line losses metering with electric meters and suggests introduction of the measured value corrections.展开更多
This paper presents the design, implementation and testing of an embedded system that integrates solar and storage energy resources to smart homes within the smart mierogrid. The proposed system provides the required ...This paper presents the design, implementation and testing of an embedded system that integrates solar and storage energy resources to smart homes within the smart mierogrid. The proposed system provides the required home energy by installing renewable energy and storage devices. It also manages and schedules the power flow during peak and off-peak periods. In addition, a two-way communication protocol is developed to enable the home owners and the utility service provider to improve the energy flow and the consumption efficiency. The system can be an integral part for homes in a smart grid or smart microgrid power networks. A prototype for the proposed system was designed, implemented and tested by using a controlled load bank to simulate a scaled random real house consumption behavior. Three different scenarios were tested and the results and findings are reported. Moreover, data flow security among the home, home owners and utility server is developed to minimize cyber-attaeks.展开更多
The monitoring of power consumption has become of a great interest in recent years as well as the innovative technologies available to realize Wireless Sensor Networks (WSNs) have experienced a great growth. While sma...The monitoring of power consumption has become of a great interest in recent years as well as the innovative technologies available to realize Wireless Sensor Networks (WSNs) have experienced a great growth. While smart metering technologies for electric energy are already established, as sensors power supply comes directly from power lines, WSN nodes for gas metering should necessarily be equipped with long life batteries. The presented work describes a new prototypal low cost WSN designed ad hoc for gas smart metering. The network has a star topology: each sensor node can be completely integrated with standard reed relay gas meter, and it is capable to measure the gas consumption. The information is sent to the central node (the Access Point, AP) through an RF links. The sensor nodes have been designed with custom electronics and a proprietary firmware, in order to work with a common 3.6 V lithium battery which is able to ensure a life period of about 10 years for each node. Only the AP must be connected directly to electric power. The AP is connected through the RS-232 interface to a control embedded PC equipped with a LAMP (Linux, Apache, MySQL, PHP) framework: it stores all the information coming from each node in a coherent database and allows authorized users to check the network status using a web interface. The WSN is self-learning and it is capable to detect new nodes joining the network without altering the normal operative flow. Moreover e-mail and SMS alerts can be activated to alert if a node is disconnected from the network or some problems occur. A first prototype of the WSN has been already tested achieving good results.展开更多
For purpose of achieving the desired thermal comfort level and reducing the economic cost of maintaining the thermal comfort of green residential building,an energy efficient thermal comfort control strategy based on ...For purpose of achieving the desired thermal comfort level and reducing the economic cost of maintaining the thermal comfort of green residential building,an energy efficient thermal comfort control strategy based on economic model predictive control(EMPC)for green residential buildings which adopts household heat metering is presented.Firstly,the nonlinear thermal comfort model of heating room is analyzed and obtained.A practical nonlinear thermal comfort prediction model is obtained by using an approximation method.Then,the economic cost function and optimization problem of energy-saving under the necessary thermal comfort requirements are constructed to realize the optimal economic performance of the dynamic process.The energy efficient thermal comfort MPC(EETCMPC)is designed.Finally,the comparison and analysis between EETCMPC and Double-layer Model Predictive Control(DMPC)is simulated.The simulation results reveal that when the clothing insulation is typical,the energy efficiency of EETCMPC is 8.9%and 11.6%,respectively,in the two simulation scenarios.When the clothing insulation varies with temperature,the energy efficiency of EETCMPC is 7.29%and 9.15%,respectively,and the total energy consumption is reduced by about 1.65%and 14.6%,respectively,compared with the typical clothing insulation.The economic performance is improved in the thermal comfort dynamic process of heating room.展开更多
With the increasing development of urban housing construction and the rapid expansion of the number of inhabitants and independent electric energy meter, a variety of tariff systems are launched, meter reading meterin...With the increasing development of urban housing construction and the rapid expansion of the number of inhabitants and independent electric energy meter, a variety of tariff systems are launched, meter reading metering becomes increasingly complex, and the traditional manual meter reading is already hard to adapt to new changes. This thesis studies the design of a centralized meter reading system. This program applies PLC technology for information transfer, which guarantees the stability of system carrier communication. This system is composed of electric energy meter, collector, concentrator and other hardware, as well as communication and management software of collection copies system. It is characterized by functions of power data collection, centralization, remote transmission, distance control, electricity analysis, line loss calculation, integrated query, and time-sharing billing. Its promotion and application will necessarily provide important technical means for power supply, property and urban utilities to improve their modernized and automatic management level.展开更多
Initiated and approved in 2009,the project of Development Pattern and Implementation Design of Smart Energy Resource Grid in China is now accomplished with the research achievement released to the public and highly va...Initiated and approved in 2009,the project of Development Pattern and Implementation Design of Smart Energy Resource Grid in China is now accomplished with the research achievement released to the public and highly valued by authorized organizations such as the Global Smart Grid Federation.In this paper,based on the description of the research achievement,the advantages of the smart energy resource grid in China and the consequential changes are analyzed and discussed,involving the industries of electric power,oil and gas,energy storage,water supply,architecture and transportations etc.展开更多
The automation technology of electric energy measurement covers all levels of electric energy measurement points. The electric energy data acquisition of power users has realized remote automatic acquisition. The tool...The automation technology of electric energy measurement covers all levels of electric energy measurement points. The electric energy data acquisition of power users has realized remote automatic acquisition. The tool for remote automatic collection of electric energy data is various metering automation terminals installed on the site. The data transmission of the automation terminal depends on various communication channels. When the field signal strength is insufficient and the communication module of the metering automation terminal cannot work normally, the terminal is offline and the data collection fails. At this time, it is necessary to solve the problem of insufficient signal through other methods, ensure the real-time communication of the terminal. This paper will introduce a technology to enhance the communication ability of terminal communication module, and illustrate the whole picture of the device through practical cases.展开更多
In recent years, in order to achieve further development, the State Grid has further increased the intelligent management of measurement assets with the construction of electric energy information collection as the co...In recent years, in order to achieve further development, the State Grid has further increased the intelligent management of measurement assets with the construction of electric energy information collection as the core and the construction of intelligent warehouse as the pillar, and taken active measures to further increase the application of the monitoring system in daily life, work and operation. In this way, the internal assets of the power enterprise are effectively controlled in an all-round way during the actual operation process, so as to further enable the related work of measurement management to be more healthy and orderly and develop continuously.展开更多
文摘Accurate electric energy(EE)measurements and billing estimations in a power system necessitate the development of an energy flow distribution model.This paper summarizes the results of investigations on a new problem related to the determination of EE flow in a power system over time intervals ranging from minutes to years.The problem is referred to as the energy flow problem(EFP).Generally,the grid state and topology may fluctuate over time.An attempt to use instantaneous(not integral)power values obtained from telemetry to solve classical electrical engineering equations leads to significant modeling errors,particularly with topology changes.A promoted EFP model may be suitable in the presence of such topological and state changes.Herein,EE flows are determined using state estimation approaches based on direct EE measurement data in Watt-hours(Volt-ampere reactive-hours)provided by electricity meters.The EFP solution is essential for a broad set of applications,including meter data validation,zero unbalance EE billing,and nontechnical EE loss check.
基金National Natural Science Foundation of China(No.51367010)Science and Technology Program of Gansu Province(No.17JR5RA083)+1 种基金Program for Excellent Team of Scientific Research of Lanzhou Jiaotong University(No.201701)Scientific Research Program of Colleges and Universities of Gansu Province(No.2016B-032)。
文摘Aiming at the shortcomings of the existing electric energy metering method,combining with the harmonic responsibility analysis model based on the reference impedance method and the idea of apparent power decomposition in IEEE Std 1459-2010 standard,two new metering indicators—billing active power and billing power factor are defined.A new electric energy metering method is proposed and its specific implementation steps are given.The simulation model is built in Matlab/Simulink,and three different examples are set up.Using the simulation data,the various metering indicators need to be examined by the existing electric energy metering method and the new electric energy metering method are calculated.The calculation results show that the new electric energy metering method not only overcomes the shortcomings of the existing electric energy metering method,but also is very easy to be popularized and applied.
文摘Currently a large effort is being done with the intention to educate people about how much energy each electrical appliance uses in their houses, since this knowledge is the fundamental basis of energy efficiency programs that can be managed by the household owners. This paper presents a simple yet functional non-intrusive method for electric power measurement that can be applied in energy efficiency programs, in order to provide a better knowledge of the energy consumption of the appliances in a home.
文摘This article puts forward an automatic recognition algorithm of electric energy meter lead seals： firstly, the image will be histogram equalization, smoothing, binaryzation pretreatment, then according to the image characteristics of text changes, the system can quickly and accurately segment image from complex background, finally the system extract different dimension and the feature of English and Arabia using digital projection transform coefficient method and to identify the corresponding number by BP neural network, solves the problem of automatic recognition of electric energy meter lead sealing.
基金the National Natural Science Foundation of China(No.51575471)the Natural Science Foundation of Hebei Province(No.E2018203028).
文摘Aiming at the problem of large energy consumption in hydraulic control system with large load and variable working conditions,based on the multi-level pressure switching control system(MPSCS),a multi-level pressure switching control system based on independent metering control is proposed combined with the independent metering control technology.The configuration principle of the system is given,the mathematical model of this system is established,and the control strategy of the system under 4 different working quadrants is put forward.Finally,the control performance and energy saving characteristics of the system are tested.The test results show that the switching of high and low pressure power supply has a certain effect on the response of step position and ramp position under impedance working condition.The displacement curves show slow climbing or abrupt change of ramp position,and the position accuracy is less than 1 mm.The multi-level pressure switching control system based on independent metering control can recover and store energy under the transcendence working conditions.The control accuracy is about 1 mm,and the energy recovery rate is about 70%~80%.
文摘Purpose-For billing purposes,heavy-haul locomotives in Sweden are equipped with on-board energy meters,which can record several parameters,e.g.,used energy,regenerated energy,speed and position.Since there is a strong demand for improving energy efficiency in Sweden,data from the energy meters can be used to obtain a better understanding of the detailed energy usage of heavy-haul trains and identify potential for future improvements.Design/methodology/approach-To monitor energy efficiency,the present study,therefore,develops key performance indicators(KPIs),which can be calculated with energy meter data to reflect the energy efficiency of heavy-haul trains in operation.Energy meter data of IORE class locomotives,hauling highly uniform 30-tonne axle load trains with 68 wagons,together with additional data sources,are analysed to identify significant parameters for describing driver influence on energy usage.Findings-Results show that driver behaviour varies significantly and has the single largest influence on energy usage.Furthermore,parametric studies are performed with help of simulation to identify the influence of different operational and rolling stock conditions,e.g.,axle loads and number of wagons,on energy usage.Originality/value-Based on the parametric studies,some operational parameters which have significant impact on energy efficiency are found and then the KPIs are derived.In the end,some possible measures for improving energy performance in heavy-haul operations are given.
文摘Correction factors of both Rem-meters, the 10 inch diameter single-sphere Remmeter and the standard A-B Rem-meter, were estimated for measuring high energy neutron dose equivalent outside a concrete shielding wall and the effects that the emitted neutron spectra become remarkably "harder" penetrated through a concrete shielding wall, and the energy response of the Rem-meter were taken in account. The estimated results could be applied in the measurement of neutron dose equivalent for the intermediate energy heavy ion reactions to avoid the difficulty induced by the energy response of the Rem-meters.
文摘智能电能表在复杂电网环境下的计量精度易受非线性误差影响。为提高其准确性,提出一种融合非线性自回归外生输入(nonlinear auto-regressive with exogenous inputs,NARX)模型与畸变功率的误差校正方法。利用NARX模型构建电能表的非线性误差模型,以捕捉其动态特性;从测量数据中分离基波与谐波电能,并计算谐波电能比差以量化谐波影响;引入畸变功率概念,构建以谐波电能比差和畸变功率为输入的误差校正模型,对非线性误差进行补偿。实验结果表明:经所提方法校正后,在不同谐波含量(5%、10%、20%)条件下,智能电能表的最大计量误差由校正前的2.4%、3.1%、10.3%均降至0.5%左右,同时非线性误差预测结果的拟合度得到了提升,有效提高了谐波环境下的计量精度。
文摘Objective<span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">: Determine the Test reliability and the objective validity of the International Physical Activity Questionnaire (IPAQ). <span style="font-family:Verdana;font-size:12px;">Methods<span style="font-family:Verdana;">:<span style="font-family:Verdana;"> IPAQ was evaluated for test-retest reliability within 6<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">-<span style="font-size:10pt;font-family:;" "=""> <span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">8 days of its first administration. Criterion validity was tested comparing IPAQ data with those from an activity meter (Intelligent Device for Energy Expenditure and Activity, IDEEA). <span style="font-family:Verdana;font-size:12px;">Results<span style="font-family:Verdana;font-size:12px;">: The test-retest correlation (n = 71) for items of IPAQ ranged from r = 0.63 to r = 0.74 and w<span style="font-family:Verdana;">as <span style="font-family:Verdana;">r = 0.79 for the total weekly PA in MET*min per week. Average PA (in MET*min/week) measured with the IDEEA meter, decreased from normal (15<span style="font-family:Verdana;">,<span style="font-family:Verdana;">840), to 14<span style="font-family:Verdana;">,<span style="font-family:Verdana;">278 in overweight<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">(BMI<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">><span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">25-<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;"><<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">30) and further to 12<span style="font-family:Verdana;">,<span style="font-family:Verdana;">803 in obese subjects (>30. BMI). The weekly energy expenditure measured by IDEEA correlated significantly (r = 0<span style="font-family:Verdana;">.<span style="font-family:Verdana;">61,<span style="font-size:10pt;font-family:;" "=""> <span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">r<sup><span style="font-family:Verdana;font-size:12px;">2</sup><span style="font-family:Verdana;font-size:12px;"> = 0.38) with the IPAQ data, providing an objective criterion for validity of IPAQ. The mean values of weekly PA estimated from IPAQ (in MET*min/week) differed significantly in the high (15<span style="font-family:Verdana;">,<span style="font-family:Verdana;">690) vs. the low (11<span style="font-family:Verdana;">,<span style="font-family:Verdana;">398) activity groups but not between the moderate (12<span style="font-family:Verdana;">,<span style="font-size:10pt;font-family:;" "=""><span style="font-family:Verdana;font-size:12px;">056) compared to the low PA group. The IPAQ criteria used to categorize subjects as moderately active, erred by including too many low PA subjects. IDEEA measurements in sedentary subjects overestimated their energy expenditure. <span style="font-family:Verdana;font-size:12px;">Conclusions<span style="font-family:Verdana;font-size:12px;">: IPAQ can be reliably used to distinguish low and high PA groups and yields relatively low estimates (−<span style="font-family:Verdana;">18%) of weekly PA in these groups compared to those measured with the activity meter. Stricter criteria are needed to distinguish moderate from low PA groups. Overweight and obese subjects showed significantly lower levels of PA than normal BMI subjects.<span style="font-size:10pt;font-family:;" "=""> <span style="font-family:Verdana;">IDEEA overestimates low levels of PA.
基金This work is supported by China Postdoctoral Science Foundation(2021M690798)Guizhou Province Science and Technology Plan Project(No.[2021]General 085)+1 种基金National Natural Science Foundation of China(No.61603034)the Fundamental Research Funds for the Central Universities(Nos.FRF-BD-19-002A,FRF-DF-20-14).
文摘With the increasing demand for petroleum resources and environmental issues,new energy electric vehicles are increasingly being used.However,the large number of electric vehicles connected to the grid has brought new challenges to the operation of the grid.Firstly,A novel bidirectional interaction model is established based on modulation theory with nonlinear loads.Then,the electric energy measuring scheme of EVs for V2G is derived under the conditions of distorted power loads.The scheme is composed of fundamental electric energy,fundamental-distorted electric energy,distorted-fundamental electric energy and distorted electric energy.And the characteristics of each electric energy are analyzed.Finally,the correctness of the model and energy measurement method is verified by three simulation cases:the impact signals,the fluctuating signals,and the harmonic signals.
文摘The quality of methods for determining energy transits on the tie lines （lines that connect two neighboring power system） can have significant impact on business activity of the TSOs （transmission system operators）. Existing law regulation is not enough precise regarding definition of methods for metering energy transits （energy interchanged between neighboring TSOs）. This paper analyses disadvantages of method for line losses metering with electric meters and suggests introduction of the measured value corrections.
文摘This paper presents the design, implementation and testing of an embedded system that integrates solar and storage energy resources to smart homes within the smart mierogrid. The proposed system provides the required home energy by installing renewable energy and storage devices. It also manages and schedules the power flow during peak and off-peak periods. In addition, a two-way communication protocol is developed to enable the home owners and the utility service provider to improve the energy flow and the consumption efficiency. The system can be an integral part for homes in a smart grid or smart microgrid power networks. A prototype for the proposed system was designed, implemented and tested by using a controlled load bank to simulate a scaled random real house consumption behavior. Three different scenarios were tested and the results and findings are reported. Moreover, data flow security among the home, home owners and utility server is developed to minimize cyber-attaeks.
文摘The monitoring of power consumption has become of a great interest in recent years as well as the innovative technologies available to realize Wireless Sensor Networks (WSNs) have experienced a great growth. While smart metering technologies for electric energy are already established, as sensors power supply comes directly from power lines, WSN nodes for gas metering should necessarily be equipped with long life batteries. The presented work describes a new prototypal low cost WSN designed ad hoc for gas smart metering. The network has a star topology: each sensor node can be completely integrated with standard reed relay gas meter, and it is capable to measure the gas consumption. The information is sent to the central node (the Access Point, AP) through an RF links. The sensor nodes have been designed with custom electronics and a proprietary firmware, in order to work with a common 3.6 V lithium battery which is able to ensure a life period of about 10 years for each node. Only the AP must be connected directly to electric power. The AP is connected through the RS-232 interface to a control embedded PC equipped with a LAMP (Linux, Apache, MySQL, PHP) framework: it stores all the information coming from each node in a coherent database and allows authorized users to check the network status using a web interface. The WSN is self-learning and it is capable to detect new nodes joining the network without altering the normal operative flow. Moreover e-mail and SMS alerts can be activated to alert if a node is disconnected from the network or some problems occur. A first prototype of the WSN has been already tested achieving good results.
基金supported by the Key Technologies R&D Program of Henan Province(Nos.202102210335/212102210026/212102210509/222102220095/212102110218)the Key Scientific and Technological Project(Social Development Field)of Henan Province,China(No.212102310093)+1 种基金the Key Scientific Research Projects of Institutions of Higher Education in Henan Province(No.20B413007)the Science and Technology Program of Henan Province Department of Housing and Urban Rural Construction(No.K-1916).
文摘For purpose of achieving the desired thermal comfort level and reducing the economic cost of maintaining the thermal comfort of green residential building,an energy efficient thermal comfort control strategy based on economic model predictive control(EMPC)for green residential buildings which adopts household heat metering is presented.Firstly,the nonlinear thermal comfort model of heating room is analyzed and obtained.A practical nonlinear thermal comfort prediction model is obtained by using an approximation method.Then,the economic cost function and optimization problem of energy-saving under the necessary thermal comfort requirements are constructed to realize the optimal economic performance of the dynamic process.The energy efficient thermal comfort MPC(EETCMPC)is designed.Finally,the comparison and analysis between EETCMPC and Double-layer Model Predictive Control(DMPC)is simulated.The simulation results reveal that when the clothing insulation is typical,the energy efficiency of EETCMPC is 8.9%and 11.6%,respectively,in the two simulation scenarios.When the clothing insulation varies with temperature,the energy efficiency of EETCMPC is 7.29%and 9.15%,respectively,and the total energy consumption is reduced by about 1.65%and 14.6%,respectively,compared with the typical clothing insulation.The economic performance is improved in the thermal comfort dynamic process of heating room.
文摘With the increasing development of urban housing construction and the rapid expansion of the number of inhabitants and independent electric energy meter, a variety of tariff systems are launched, meter reading metering becomes increasingly complex, and the traditional manual meter reading is already hard to adapt to new changes. This thesis studies the design of a centralized meter reading system. This program applies PLC technology for information transfer, which guarantees the stability of system carrier communication. This system is composed of electric energy meter, collector, concentrator and other hardware, as well as communication and management software of collection copies system. It is characterized by functions of power data collection, centralization, remote transmission, distance control, electricity analysis, line loss calculation, integrated query, and time-sharing billing. Its promotion and application will necessarily provide important technical means for power supply, property and urban utilities to improve their modernized and automatic management level.
文摘Initiated and approved in 2009,the project of Development Pattern and Implementation Design of Smart Energy Resource Grid in China is now accomplished with the research achievement released to the public and highly valued by authorized organizations such as the Global Smart Grid Federation.In this paper,based on the description of the research achievement,the advantages of the smart energy resource grid in China and the consequential changes are analyzed and discussed,involving the industries of electric power,oil and gas,energy storage,water supply,architecture and transportations etc.
文摘The automation technology of electric energy measurement covers all levels of electric energy measurement points. The electric energy data acquisition of power users has realized remote automatic acquisition. The tool for remote automatic collection of electric energy data is various metering automation terminals installed on the site. The data transmission of the automation terminal depends on various communication channels. When the field signal strength is insufficient and the communication module of the metering automation terminal cannot work normally, the terminal is offline and the data collection fails. At this time, it is necessary to solve the problem of insufficient signal through other methods, ensure the real-time communication of the terminal. This paper will introduce a technology to enhance the communication ability of terminal communication module, and illustrate the whole picture of the device through practical cases.
文摘In recent years, in order to achieve further development, the State Grid has further increased the intelligent management of measurement assets with the construction of electric energy information collection as the core and the construction of intelligent warehouse as the pillar, and taken active measures to further increase the application of the monitoring system in daily life, work and operation. In this way, the internal assets of the power enterprise are effectively controlled in an all-round way during the actual operation process, so as to further enable the related work of measurement management to be more healthy and orderly and develop continuously.
