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The construction requirements of the global energy internet greatly promote the information-based and intelligent development of electric power equipment. As the important component of electric power equipment, voltage transformer adopts the double-side detection method. As a result, the transformer is large in volume and weight, and inaccurate in detection, etc. With regard to the existing problems of the current voltage transformer, the non-contact voltage sensor is proposed on the basis of the near field detection method in this paper to achieve the voltage detection in power transmission line and other electric devices. New method and means are provided for the voltage detection of electric power system, contributing to promoting the information-based intelligent development level of electric power equipment in the global energy internet construction.

With the gradual popularization of electric vehicles, users have a higher demand for fast charging. Taking Tongzhou District of Beijing and several cities in Jiangsu Province as examples, the charging demand of electric vehicles is studied. Based on this, combining energy storage technology with charging piles, the method of increasing the power scale of charging piles is studied to reduce the waiting time for users to charge. Based on the consideration of safety and cost of distribution network, an optimization scheme of capacity allocation for energy storage devices to access the distribution network is designed. Finally, taking a city's distribution network as an example, a Simulink model is established to simulate the impact of large-scale electric vehicles to the distribution network, and the operation of the distribution network is analyzed after the optimal allocation scheme of energy storage capacity is adopted.

Ferrite materials have good frequency characteristics. Their relative permeability is large and relative permittivity is small. These make it suitable for matching layer and have a good application prospect in broadening the absorption bandwidth. In this paper, ferrite was prepared by a simple chemical precipitation-dehydration method, and the ferrite Fe3O4 particles with 40% mass fraction were mixed with paraffin to form a ring test sample. The experimental results show that the as-prepared sample at higher temperatures has more stable nucleation and fewer defects, so it has more significant electromagnetic wave absorption performance. The minimum reflection loss is about - 44 dB, and the electromagnetic absorption band with the reflection loss RL less than - 10 dB is located at 12.5-14.1 GHz (3 mm) and 6.5-8.1 GHz (5 mm), respectively.

Reduced graphene oxide (RGO) was successfully prepared by reducing graphene oxide (GO) by zinc powder in this paper. Then the reduced graphene oxide (RGO) was combined with Fe and Ni nanoparticles to form RGO/Fe and RGO/Ni composite absorbing materials. The morphology, chemical composition, magnetic properties and electromagnetic parameters of RGO/Fe and RGO/Ni were characterized by means of scanning electron microscopy(SEM), X-ray diffraction(XRD), vibrating sample magnetometry (VSM) and vector network analysis (VNA) to study absorbing mechanism of the as-prepared RGO/magnetic-metal composites, including the effect of magnetic particles Fe and Ni on the absorbing properties. The results showed that in the frequency range of 2-18 GHz, the effective absorption band of RGO/Fe was wider than that of RGO/Ni, with larger reflection loss.

Dendritic-like Co particles consisting of leaf-shaped nano-units were successfully synthesized by chemical reduction method. The absorbing particles have abundant multi-stage branches. Since the crystal structure, size and special morphology have an important influence on the microwave absorption performance, the X-ray diffractometer, scanning electron microscope, vibration sample magnetic measurement and vector network analysis are used to characterize the dendritic Co. Absorbing mechanism was analyzed systematically. The nano-sized, multi-stage branches, porous structures and rough surfaces of the prepared particles all contribute to the penetration, scattering and attenuation of EM waves. Hence the composite, in the test band, especially in the S-band (2-4 GHz), presents excellent microwave absorption properties.

The smart meter is one of the necessary equipment for building a smart grid system. Its reliability directly affects the safe and stable operation of the smart grid system and it is also directly related to the reliability and safety of power supply for thousands of households. In this paper, the reliability modeling and evaluation method of smart meter is proposed. The initial trend of the frequency histogram and cumulative distribution function is used to select the distribution model of smart meter. Then, the final distribution is determined according to parameter estimation and model fitting test, and the reliability of smart meter can be achieved. The case example shows that the method is simple and effective. Under certain conditions of the sample size, the method is an effective means of system reliability statistical modeling.

In this paper, we present a no-reference image sharpness metric using the directional derivatives. The main idea is from the meaning of sharp which involves a sudden or abrupt change in direction or course. In other words, people have a feeling of sharpness when they receive sudden changes in some direction during their observations of an image. The metric is composed of three steps. First, the directional derivatives of the input image are computed by directional derivative filters. Then the maximum and minimum of these directional derivatives are selected to construct the absolute changes and relative changes which are proportional to the sudden changes received by an observer. Finally, the sharpness metric is determined by a weighted average of these changes. Our experiment on three simulated blur images demonstrates the proposed sharpness metric is competitive the relevant sharpness metrics for evaluating both real and synthetic blurring.

Voltage sensors are an important part of the electric system. In service, traditional voltage sensors need to directly contact a high-voltage charged body. Sensors involve a large volume, complex insulation structures, and high design costs. Typically an iron core structure is adopted. As a result, ferromagnetic resonance can occur easily during practical application. Moreover, owing to the multilevel capacitor divider, the sensor cannot reflect the changes of measured voltage in time. Based on the electric field coupling principle, this paper designs a new voltage sensor, the unipolar structure design solves many problems of traditional voltage sensors like the great insulation design difficulty and high costs caused by grounding electrodes. A differential signal input structure is adopted for the detection circuit, which effectively restrains the influence of the common-mode interference signal. Through sensor modeling, simulation and calculations, the structural design of the sensor electrode was optimized, miniaturization of the sensor was realized, the voltage division ratio of the sensor was enhanced, and the phase difference of sensor measurement was weakened. The voltage sensor is applied to a single-phase voltage class line of 10 kV for testing. According to the test results, the designed sensor is able to meet the requirements of accurate and real-time measurement for voltage of the charged conductor as well as to provide a new method for electricity larceny prevention and on-line monitoring of the power grid in an electric system. Therefore, it can satisfy the development demands of the smart power grid.

SF6 decomposition characteristics under partial discharge (PD) are not only associated with insulation fault type and its severity but also closely related to the H2O content of in the equipment. This paper studies the decomposition characteristics of mixture gas SF6/H2O with six different gradients of trace H2O under the same PD energy, selects SO2F2, SOF2, CO2, and CF4 as the characteristic components, and analyzes the influence regularity of trace H2O on each of the component concentration, effective formation rate and characteristic ratio. Results show that H2O creates favorable conditions for generating SO2F2 and SOF2 owing to the capacity to capture F atom and inhibit low fluorine sulfides from recombining into SF6. As a result, the concentration and effective formation rate of SO2F2 and SOF2is positively related with H2O. Whereas H2O has no evident influence on CO2, it can consume intermediate by-products CF2 and CF3 which restrain CF4 generation. Each characteristic ratio decreases sharply and then becomes stable with increment of H2O. The defined effective characteristic ratio effectively reflects its relationship with H2O, whereas obtained mathematical expression between each effective characteristic ratio and trace H2O lays solid foundation for fault diagnosis of SF6 insulated equipment based on SF62 decomposition characteristics.

In recent years, much attention has been paid to multiple-input-multiple-output (MIMO) signal processing in power line communication (PLC), to increase channel capacity and anti-interference ability. In this study, an adaptive filter was designed to reduce the influence of interference and bit error rate in MIMO-PLC random channel. This filter was set in the receiving port of a 3×4 MIMO-PLC system. The bit error rate before and after adding filter was analyzed and compared. Results show that the filter provides a remarkable performance gain on bit error rate in this 3×4 MIMO-PLC system.

To obtain the influence regularity of trace O 2 on SF 6 decomposition characteristics under partial discharge (PD) and establish the foundation of using SF 6 decomposed components to diagnose the insulation status of SF 6 electrical equipment, first, a series of PD decomposition experiments with different O 2 concentrations (%)were conducted on a special experiment platform. The variation regularity between the concentrations of characteristic components and the different content of O 2 were obtained quantitatively. Second, the correlation coefficient r testing method was applied to identify the associated influence of trace O 2 on the decomposed characteristic components and characteristic ratios. Based on this, an exponential regression model of the related characteristics was developed. Finally, the influence mechanism of trace O 2 on SF 6 decomposition progress was explained reasonably. The results show that under the PD caused by metal protrusion insulation fault without organic solid insulated materials, CO 2 , SO 2 F 2 , and SOF 2 were the mainly decomposed components in the specific range of trace O 2 . Although no obvious influences of the trace O 2 on the concentrations of CO 2 and SOF 2 as well as the ratio c(CO 2 )/c(SO 2 F 2 +SOF 2 ), it is notable that the trace O 2 is negatively and positively related to the concentration of SO 2 F 2 and the ratio c(SOF 2 )/c(SO 2 F 2 ), respectively. The exponential regression model can minimize the effect of trace O 2 on the fault diagnostic result when using SF 6 decomposed components.

To obtain the inner correlation feature between SF6 decomposition characteristics caused by the partial discharge (PD) of the free metal particle insulation fault and charge magnitude, a series of experiments are conducted on the designed experimental system. Three methods, namely, gas chromatograph, chromatography-mass spectrometry and Fourier infrared spectroscopy, are used to quantitatively measure the decomposed components. Their content relation under different PD magnitudes is obtained and determined as SOF2 > SiF4 > SOF4 > SO2F2 > SO2 > S2F10 > CO2 > CF4, where the content of highly toxic S2F10 greatly exceeds its safe threshold. The study also discusses the correlation feature between each component of the free metal particle insulation fault and charge magnitude, which is found only when the charge magnitude reaches the point where it promotes the obvious formation of the components. Each component formation is found positively related to PD quantity. Based on a stability analysis of the produced components, five components are proposed to represent PD strength and the diagnosis table to recognise the severity of the metal particle insulation fault. This study attempts to lay a solid foundation for the conditional assessment of SF6 insulated equipment.

Partial discharge (PD) with different energy always occurs before a serious breakdown in sulfur hexafluoride (SF6) insulating equipment. The high electromagnetic energy of PD can cause the insulation gas SF6 to decompose into various components. Component types and their formation rate are directly related with insulation fault severity. Hence, PD energy can be evaluated based on the characteristics of SF6 decomposition, which could be further used to diagnose insulation status. This paper focuses on the SF6 decomposition mechanism under PD, establishes the feature parameter to describe PD energy, and clarifies the feature parameter?s physical significance. In addition, this paper defines the effective energy characteristic ratio ERRMS and analyzes the relationship between ERRMS and PD energy. Finally, this paper discusses the influence regularity of trace H2O and O2 on ERRMS.

Electricity Information Acquisition System (EIAS) test platform is used to evaluate the communication performance of the different communication methods. For realizing the reliable and quick information interaction in the test terminal, a hierarchical structure multi-network convergence communication mechanism is designed. The convergence communication mechanism is divided into the communication interface convergence layer, the core convergence layer and the business convergence layer to realize the information interaction among the Ethernet communication, power line carrier communication, RS-485 communication and wireless communication. Combined with the tunnel transmission mechanism, the buffer pool mechanism, the communication check mechanism and the timeout control mechanism, the multi-network convergence communication mechanism can effectively improve the communication performance of the test terminal. The test results show that the mechanism can satisfy the real-time and reliability requirements for the electricity information acquisition system test platform.

In today’s society, the economy is gradually transforming to green and low-carbon. As the core link of the low-carbon industry of electric vehicles, charging facilities have great potential to participate in the carbon trading market. In this context, in order to promote healthy and orderly development for electric vehicle charging infrastructure industry and ensure its participation in carbon market economy, based on the analysis of the development trend of China’s future carbon trading market, this paper studies the business model of typical electric vehicles charging facility projects participating in the carbon trading market from three aspects of business structure, profit channel and operation mechanism, so as to improve the income level of charging facility operators while improving the carbon trading market.

The development of electric vehicles(EV) has been widely established as an important way to ensure energy security and transform low-carbon economy in the world. However, the construction and operation cost of EV charging facilities is high and the profit channel is single, which makes operators in a long-term loss state. It is necessary to study the participation of EV charging facilities in carbon trading in order to find new profit growth points. On this background, firstly, the calculation method of carbon emission of whole life cycle of EV charging facilities is studied from the construction stage and the operation stage, which shows that the carbon emission accounting has technical feasibility. Secondly, the economic benefits of EV charging facilities participating in carbon trading market is analyzed, which shows that participating in carbon trading has economic rationality. Finally, a case study of the carbon emission accounting and economic benefits of EV charging facilities participating in carbon trading is carried out. The result shows that the economic benefits of EV charging facilities participating in carbon trading increase, and with the increase of charging amount and carbon trading price, the economic benefits increase continuously.

To obtain relationship between concentration of SF6 decomposed characteristic components (or their concentration ratio) during the formation process and partial discharge qualities and pulse repetition rate, this paper used needle-plate electrode to simulate outthrust insulation fault and conducted a serial of experiments. First, the SF6 decomposition characteristic under different PD strengths is obtained. Then this paper defines average discharge qualities per second as QSEC. It considers both apparent discharge qualities and discharge pulse repetition rate, and analyzes the relation feature between SF6 decomposition characteristic (both concentration of component and their effective formation rates RRMS) and QSEC. Besides, it proposes C(SO2F2)/C(SOF2) as the energy characteristic ratio (ER) to represent PD energy, and defines the effective energy characteristic ratio as (ERRMS). Moreover, it achieves the inner correlation feature between QSEC and all the characteristic component concentration, the RRMS of each characteristic component and ERRMS. The results show that: since number of C atoms from stainless steel surface and content of trace H2O and O2 in gas chamber were limited, both decomposed component concentration and component concentration ratio accords with the famous "Logistic Population Model" growth trend in ecology, which means they present "S"-curve increase with QSEC. The proposed ER can effectively indicate the amount of PD energy and the defined ERRMS can objectively reveal the variance regularity of PD energy with QSEC. Hence, the correlation mathematic formula between ERRMS and QSEC is obtained and ERRMS can be used as the new characteristic parameter to represent PD energy. It establishes the foundation for the further fault diagnosis research.

Fiber optical current sensor(FOCS) has widely used in the field of electric power measurement by which the current measured generally is hundreds of amperes even thousands amperes. A smaller fiber sensing coil is required in order to that the FOCS meet the needs of the high voltage watt-hour meter for measuring smaller current with the better performance. In this paper a FOCS with small size sensing coils (

High voltage transmission lines have a clear and necessary straight-line feature, which can be obtained by using the method proposed in this paper to process captured images. Since high voltage transmission lines operate in a complex environment, it not only increases the noise in captured pictures, but also makes it harder to extract the transmission lines due to background interference. In order to reduce the impact of complex background and other flanking transmission lines, a novel algorithm based on opening and closing operations is proposed to facilitate extraction of the transmission lines by using the Hough transform technique. From the experiments, it is found that the novel algorithm realizes the goal of extracting the main transmission lines.

In order to better understand the power frequency electric field around the transmission lines and device, this study introduces the mathematical measuring principle of one-dimensional spherical sensor for electric field, analysis the theoretical feasibility whether the ball-type sensors could be replaced by the parallel plate capacitive sensor and discuss the effects of different sizes of parallel plate capacitive sensor for electric field measurements and then complete the design of sensor. The design of overall system and operating principle of the safety warning instrument are introduced and the relevant hardware and software circuit design are completed. After debugging, a high voltage electric field measuring based on the C8051F410 microcontroller is designed. In the 750kV substation and transmission line space below, the measured data have greater relevance with good usability after comparing the foreign standards and the instruments designed.

In this paper, a novel printed monopole antenna with two band notches is presented for applications in wireless communications. The proposed antenna consists of a microstrip fed ring-shape radiator, a backed rectangular metallic plate and a ground plane with two H slots. The simulated results show that the antenna has three operating bands (2.36 to 2.94 GHz, 3.26 to 4.04 GHz and 4.86 to 6.44 GHz). The measured results coincide with the simulated ones. The designed antenna is small, low profile and inexpensive, which is suitable for applications in wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX).

This paper proposes a novel gripper for power transmission lines inspection robot. The proposed gripper has advantage of obstacles avoidance. The whole weight of the robot could be supported by the grippers with ball bearings design. The passive rolling motion through ball bearings greatly reduces the friction force between the power transmission cable and the robot, with the result of having a less damage to the cable. What's more, the emergency braking parts are added to improve security. In addition, a pair of worm gears with self-locking characteristic is used together. It also has large workspace feature with good adaptability for inspection applications on different diameter cables. A test-bed was built for maneuverability evaluation. Numerous experiments were conducted, and the experiment results show that the proposed gripper is efficient for robots maneuverability.

The measuring accuracy of electric energy meter is not only related to the normal operation of power system, but also related to the vital interests of users. So the appropriate evaluation of its running state is particularly important. In this paper, according to its working principle and running characteristics, various influence factors of its operating error are summarized. Combining the online and offline information and taking the actual running environment of power grid into consideration, the evaluation index are selected to build a comprehensive running state evaluation index system based on the environment, importance and reliability, which can provide theoretical reference for the current electric energy metering device management.

In order to build an electricity information collection system with the satisfied communication performance in the smart grid, it is essential to evaluate the communication performance for low-voltage power line carrier communication (PLC), RS485 communication and short range wireless communication used widely in the electricity information collection system. A communication performance test platform based on the multi-network fusion technology is designed in this paper. By comparing the comprehensive assessment value of the communication performance for different communication modes, the optimal communication mode can be selected. The test results indicate that the test platform can effectively evaluate the communication performance of the multi-network and make a choice for the optimal communication mode in the construction process of the electricity information collection system.

The embedded test terminals used in the electricity information acquisition test system are limited to the RAM space and the CPU processing ability, so the integral TCP/IP protocol is difficult to be used in the test terminals. A simplified TCP/IP protocol stack is designed for the electricity information acquisition test system. The simplified TCP/IP protocol stack can accomplish the basic communication of TCP/IP function including the ARP, ICMP, IP, UDP, TCP, the dynamic configuration of IP address, Client/Server mode switch and the MSS Buffer mechanism of TCP, but the RARP, IGMP and the sliding window mechanism of TCP which are otiose to the test terminals can be cut. The test results show that the protocol stack can accomplish the TCP/IP communication and satisfy the reliability and real-time property of the electricity information acquisition test system.

This paper presents a model for computing Power frequency electromagnetic field of over head high voltage transmission line based on Simulation Charge Method. Based on this model, the electric field intensity under power line is calculated and the distribution is analyzed in different condition such as different distant between phase line, different phase order for double circuit, and different arrangement of line in single circuit or double circuit. According to the simulation results, the electric fields under over head transmission line can be forecast. This is no doubt important in environment protection and available in the design of transmission line.