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Electric power and natural gas systems are not separated but rather are increasingly connected physically and functionally interdependent due to the continuing development of natural gas-fired generation and gas industry electrification. Such interdependency makes these two systems interact with each other when responding to disasters. The aggravated risk of cascading failures across the two systems has been exposed in recent energy crises, highlighting the significance of preparing these interdependent systems against disasters and helping their impacted services quickly recover. This promotes us to treat power and gas systems as one whole to fully capture their interactive behaviors. In this paper, we focus on the interdependent electric power and natural gas distribution systems (IENDS) and propose a "supply - demand - repair" strategy to comprehensively help the IENDS tide over the emergency periods after disasters by coordinating mobile or stationary emergency resources for various uses. Specifically, 1) on the supply side, the fuel supply issue of different types of generators for emergency use is considered and the fuel delivery process among different fuel facilities is mathematically formulated; 2) on the demand side, a zonewise method is proposed for integrated dispatch of power and gas demand responses; and 3) in the repair process, a varying efficiency related to the repair units at work is introduced to accurately model repairs. The proposed strategy is formulated into a mixed-integer second-order cone programming model to obtain a globally optimal decision of deploying all of those resources in a coordinated and organized manner. A series of case studies based on test systems are conducted to validate the effectiveness of the proposed strategy., 31 pages, 9 figures, submitted to Applied Energy

Aiming at the problem that the existing standard power meter verification process and result judgment are overly dependent on the operation of the personnel, a verification strategy optimization method based on knowledge graph is proposed and applied to the standard power meter verification process. A semi-automatic approach is taken to construct the knowledge graph, and it is used for knowledge reasoning of verification process. Experimental results show that the proposed method has high accuracy and can improve the verification efficiency by about 20%.

Electromagnetic interference (EMI) from the low-voltage power-line network has been a major concern for the power-line communications (PLC) technology. The conventional EMI measurement is based on the mixed mode, including common mode, and differential mode (DM). However, the dominant transmission mode of PLC is DM. Therefore, for electromagnetic compatibility designing purposes, knowledge of the DM noise of the household appliances in the frequency range of 150 kHz to 30 MHz is essential to provide insight of conducted disturbance on the low-voltage power-line network. In this paper, a simple and useful method of DM conducted emission (DMCE) measurement using a PLC coupler is proposed and it offers a suitable interface and a convenient way for the household appliance to obtain the DMCE with the existing equipment. The obtained results compare the levels of DMCE and mixed-mode conducted emission (MMCE) from different kind of household appliance. It shows that even when MMCE meets the current limits in standard CISPR 14, DMCE may still exceed these limits. In order to suppress EMI on the PLC network, the limits and measurement methods of DMCE for the household appliance should be taken into account in the future.

Sensitive equipment such as electric vehicle control systems and vehicle electronics are susceptible to the external electromagnetic environment. The radiated electromagnetic signals interfere with the normal driving of electric vehicle and threaten human life. In order to ensure safety and reliability of electric vehicles, electromagnetic (EM) absorbent has become a key technology. RGO/Ni was prepared by in-situ reduction method in this paper. Since composition, size, and special morphology have a vital influence on microwave absorption properties, the as-obtained products were characterized by X-ray diffraction, scanning electron microscopy and vector network analysis. Different reduction methods will bring different dielectric properties to the obtained RGO. The RGO obtained by Zn powder have a more complete structure, and therefore better dielectric properties. The prepared RGO/Ni-2 composite possesses excellent impedance matching characteristics and electromagnetic complementary effect, which are beneficial to microwave absorption performance. In this paper, the absorption mechanism of RGO/Ni-2 is studied, which provides an effective way for the preparation of GRO/Ni, and introduces the application of RGO/Ni as a high-efficiency absorber in the field of electric vehicles.

Faults in the grounding grid are a hidden danger to the safety of power systems and cause significant economic loss every year. This paper presents a new means to locate faults in grounding grids using the transient electromagnetic imaging method. The method compares the distribution characteristics of the equivalent resistivity of the underground covered by grids for the no-fault case and those with break points. We describe why and how the proposed method can be used for the break-point diagnosis of grounding grids. Simulation was performed using the Ansoft finite-element method package, and a field experiment was conducted to verify the effectiveness of the proposed method. This study provides a practical means for break-point diagnosis with no requirement of power shut down or soil excavation. Moreover, the proposed method does not require the design drawings of grounding grids.

Studies have shown that there are a lot of low-voltage power line is one of the main obstacles to strong noise limit for data transmission quality. Power line noise can be divided into steady background noise, narrowband interference noise, sudden impulse noise and periodic noise. Background noise is distributed throughout the communication band, low-voltage power line up white Gaussian noise 22dB [133 or more. Sudden noise is generated by the random access or disconnect electrical equipment produced. Studies have shown that pulse interference effects on the quality of the low voltage power line carrier communication maximum. Literature statistics, intensity pulsed interference up 40dBuv.

Aiming at the periodic verification difficult problems of electric vehicle energy meter, put forward a kind of real — time on — line detection scheme of energy metering accuracy un6497der working conditions of electric vehicles, and developed successfully portable on-line detection device of DC energy meter for vehicles. Achieved high-precision current sampling by using zero-flux current sensing technology, reduced the device detection error jump through the average pulse method to improve the detection accuracy of the device. Selected electric vehicle operating conditions to road test, the actual program measurement accuracy can reach 0.2s level, can be applied to on-line detection of vehicle DC measuring instruments below level 1, with a certain value to promote.

Low-voltage power line channel characteristics are designed for low voltage power line carrier communication system foundation. The paper used to design and develop a system for measuring the electrical characteristics of the low voltage power line communication network used to do high, including the noise characteristics of the input impedance characteristics, signal attenuation characteristics and systems, etc., a lot of experimental research. On this basis, the establishment of a low-voltage power grid will be used as a high-frequency carrier communication channel model. The model provides a practical and effective platform for the research and design of low voltage power line carrier communication system network has laid a good foundation.

Low voltage power line carrier communication simulation software and simulation test system is analog carrier communication channel environment in different ways, the two systems complement each other, the former design stage for communications equipment, flexible and comprehensive simulation of the channel complex transmission characteristics; the latter stages of a communication device for debugging, you can be more effective and intuitive reflect any change in the characteristics of the load. This paper describes the combination of the two respective characteristics of its ability to effectively simulate the actual channel transmission characteristics.

The interoperability test between electric vehicle and charging equipment plays an important role on the popularization and application of electric vehicles. The principle of control pilot circuit of charging equipment is introduced firstly. Based on new national standard and the new charging interoperability test specification, the interoperability testing device of A.C. charging spot is designed and the device is used to test the interoperability test items. The test results show that the following problems exist in the interoperability test of the charging spot: (1) the potential of power supply exceeds the allowable range of ± 0.8V. (2) Charging connection control timing does not meet the standard requirements. (3) When the charging spot is under abnormal condition, it can't disconnect the AC power supply circuit within the specified time.

with the national new energy strategy periodically adjusting and continuously advancing, the construction of electric vehicles charging infrastructure getting increasingly closing, the problem of power supply capacity prediction that the social users in some region use it to charge their electric vehicles is the key issue that affects the power grid construction. In this paper, a forecasting method that based on machine learning is proposed to solve the problem.

The electric vehicle parameters collected by timesharing lease management platform have been accumulated increasingly, which has laid a firm foundation for large data analysis. Pretreatment technology plays an important role in the process of data acquisition. In particular, there is a risk of intervention in the process of transmitting monitoring data between two platforms. Therefore, this paper puts forward the prediction method of decision tree analysis based on Kalman filter by adopting the intervention probability curve of monitoring data and the quantitative relationship between the covariance ratio, putting the intervention probability curve interval and measurements as input to establish a regression relationship, and adding the object decision tree into the traditional Kalman filtering algorithm. This method can reduce the intervention effects, and achieve filtering and predicting function for the data collected by the main operating platform, which lays a solid technical support for big data analysis efficiently.

External load switch equipped in electricity meter play an important role in the normal operation of the terminal circuit and equipment. Therefore, it has important practical significance to analyze and improve the common failure modes of external load switch equipped in electricity meter. This paper introduces several common failure modes of external load switch equipped in electricity meter, analyzes the failure modes and takes the corresponding improvement measures, which can effectively improve the reliability of the use of external load switch equipped in electricity meter.

The use of semi-physical simulation platform for school laboratory and classroom building scene a lot of field measurements, analysis of power line channel transmission characteristics of the different environments, and features a three-dimensional graphic display of variable power line channel under different scenarios. At the same time in order to improve the efficiency of the data analysis, the use of MATLAB simulation software design based on off-line data analysis software GUI interface. It receiving end signal processing module integrated into the GUI interface, to implement graphical data analysis and processing, and at the same time from multiple dimensions of the channel parameters display.

A standard source of homogeneous magnetic field is essential to calibrating magnetic measurement equipment. The magnetic field distribution generated by cube four-turn coil device which is taken as the standard magnetic field source is deduced theoretically. Simulation was performed using ANSYS Maxwell software, and the results agree with the theoretical calculation very well. We discuss the homogeneity of magnetic field generated by cube coil device in axial and vertical axis direction, and results show that it can produce magnetic field of high homogeneity in a considerable area around the device center. For cube four-turn coil device with 1 m side, the bias ratio of magnetic induction intensity is within 0.25% in the central 0.2m×0.2m×0.4m cuboid. Compared with Helmholtz coil, the cube four-turn coil device has significant advantages on both homogeneity and field size as standard homogeneous field generating devices.

A symmetric extension method for basis expansion modelling (BEM) under a fast-varying channel is proposed. The conventional DFT BEM approach suffers from power leakage and results in a modelling error floor, especially at the channel boundaries. Proposed is a novel symmetric extension method to reduce the leakage power efficiently. Numerical results show that the performance of the proposed channel modelling method is robust under different normalised Doppler frequencies and the modelling errors at the channel boundaries can be eliminated substantially.

A new adaptive subcarrier grouping scheme is proposed to maximize capacity of single-carrier FDMA (SC-FDMA) system. In OFDM system, the SNR of each subcarrier is dependent on the frequency selective channel fading. While in SC-FDMA system, the SNR of each symbol is of the same value. Theoretical analysis shows that the SNR of the received SC-FDMA symbol is dominated by some few deepest fading subcarriers. With the sacrifice of not using these subcarriers, the whole system performance can be significantly improved. This characteristic inspires us to propose a new algorithm to maximize overall system capacity. Different from the conventional adaptive power allocation method, we only need to decide whether to use some of the deepest fading subcarrier by our proposed adaptive grouping algorithm, and indicate grouping decision to the receiver. Simulation results show that the capacity improved by our method compared with the conventional SC-FDMA system. The average grouping information is very small, and the indication overhead is negligible compared with the whole system capacity. The PAPR is increased slightly. Our method provides a flexible tradeoff between the system performance and PAPR.

Comprehensive and well-founded knowledge of the wireless indoor channel is fundamental to establish realistic modeling of the channel characteristics. The growing wireless technology is providing new potential for emerging applications such as in the IEEE 802.16d systems. With the development of communication technology, modern wireless communication systems gradually operate in increasingly high frequency bands. In this paper, a frequency-domain measurement method for the indoor environment propagation is presented. Data of the IEEE 802.16d are collected at a frequency of 2.422 GHz, where the inverse fast Fourier transformation (IFFT) is employed to obtain the time-domain channel impulse responses with an obstacle between transmitting antenna and receiving antenna at different locations. The Rohde & Schwarz(R&S)SMU2000A Vector signal generator(VSG) is connected with the transmitting antenna, and the Agilent Vector signal analyzer(VSA) PIX is connected with receiving antenna to collect the receiving data, then the channel characteristics are derived by matlab. Our extensive validation combines test-bed experiments and simulations. The numerical results of indoor wireless channel characteristics such as frequency-domain channel impulse responses and time-domain channel impulse responses are extracted and briefly reported here.

This article studies the property of wireless power transmission (WPT) system by electromagnetic full-wave simulation method when half-space condition is considered. Specially, the Time Domain Integral Equation (TDIE) is applied in this simulation. With this time domain method, the WPT without the ground is analyzed and compared with the traditional method, which has demonstrated the validity and high efficiency of this simulation method. After that, TDIE is applied to analysis the impact of infinite ground to the performance of WPT system which is a common situation when the WPT system is applied. The simulation results demonstrate that the ground will increase the resonant frequency and decrease the efficiency seriously. Besides, the ground will also bring along the split of resonant frequency in the traditional under coupled area.

In this paper we investigate dynamic frequency reuse scheme for cellular system enhanced with two-hop fixed relay station (RS). Frequency reuse can increase spectrum efficiency. However, it will also introduce more interference. In order to reuse more frequency resources with satisfactory quality of service (QOS), we propose an adaptive frequency reuse scheme according to the desired interference level. Both inter-cell and intra-cell reuse are considered. No interference measurement is needed, the signaling overhead is reduced. Numerical results show that in our proposed scheme the signal to interference ratio (SIR) performance on the cell edge is improved significantly, the spectrum efficiency is also increased.

This article has analyzed some questions which exist in the work of watthour meter management, introduced the concept of LCC, the constitution of LCC, and the management of LCC, has emphatically analyzed the LCC constitution of watthour meter, and has carried on the computation and the analysis to several kinds of single-phase watthour meter, elaborated the application of LCC theory on the watthour meter management.

At the present time, substation equipments are inspected one by one by electric power workers in our country. It not only costs much manpower and material resources, but is also inefficient and insecure. The laser guided AGV based robot system used in substation inspection is a much better choice to solve the above problems. AGV, namely automatic guided vehicle, is a kind of simple mobile robot, which integrates sound, light, electricity and computer. And it is applied in the fields of industry manufacture and logistics widely and maturely. Improving the laser guided AGV in configuration, location, run and control software and so on combined with the requirement of substation operating standard, and then the improved AGV can be used in automatic inspection of substation equipments. The paper introduces the theory and application of laser guided AGV briefly, analyses the feasibility of improving AGV to meet the requirements of field environment and operation standard of substation, and then the design scheme of AGV based robot system used in substation equipment inspection is brought forward. The robot system can replace workers to inspect equipments in substation automatically or remote-controlled, and the operation automation of substation is improved to a new level. Accordingly, the application in substation inspection of the robot system based on laser guided AGV has notable economical benefits and social significance.