Table of contents

A novel compacting print planar monopole UWB antenna with two ultra narrow and closely space band-notched characteristics for low WLAN (5.15∼5.35GHz) and high WLAN (5.725∼5.825GHz) applications is presented. The antenna is one of the smallest UWB antenna found in the open literatures because of its overall size of 20×16 ×0.8(mm³). Especially, by employing two open-circuited stub pairs (OCSPs), dual-band-notched characteristics are achieved. The notched bands is ultra narrow of 0.26GHz and 0.18GHz, respectively, to suppress the interferences of lower and higher WLAN band just enough. And the space between two notched bands is 0.53GHz. These features make a good proof that OCSP could reject narrow bands in both antenna and BPF.

With the improvement of radar technology, performance of traditional chaff jamming is decreasing constantly. Aiming at the imbalances between the development of chaff jamming and radar technology, a new chaff jamming technology—nano-chaff — is proposed. The basic characteristics of nano-chaff were analyzed before introducing the concept of ideal chaff bomb and studying its scattering characteristics. Simulation results show that, nano-chaff has low radiant efficiency, for which its advantage of loading quantity can make up. Additionally, compared with traditional chaff, it can enhance the RCS of single ideal chaff cartridge. The result can provide some theory basis for applied research subsequently.

Because of the wind power generation characteristics, the wind turbine's dispatch model is based on wind power prediction. Even though the current average forecast error of ultra-short-term wind power prediction is already low, there are still some errors and uncertainties. Therefore, the scenario analysis method is used to estimate the forecast error. The deterministic modeling is realized by using the spare amount. In order to plan the operating cost of the wind farm reasonably, the scenario analysis method and the possible spare cost are combined with the idle cost of the unit to establish an economic dispatch model within the wind farm. The example analysis shows that the model is feasible.

For the problem of particle degradation and depletion in the blind separation of particle filter algorithm, particle swarm optimization algorithm and genetic algorithm are used to improve the traditional PCMA blind separation algorithm based on particle filter. The improved algorithm uses particle swarm optimization algorithm to optimize the particle and uses genetic algorithm to resample the particle. It can maintain the diversity of particles and reduce the problem of particle degradation and dilution effectively. The simulation shows that the improved blind separation algorithm has better separation performance.

Aiming at the permanent magnet synchronous motor (PMSM) with rotor eccentricity fault, two-dimensional static and dynamic eccentric models of PMSM are established respectively based on the finite element software EasiMotor. Through the simulation and the Fourier transform, air-gap flux density and radial electromagnetic force are solved. Simulation results show that the rotor eccentricity is an important influence factor for PMSM used in electric vehicle, which can be reference for further research on rotor-eccentricity magnetic field.

Multi-path effecting and Dopplereffecting on missile-borne tester signal transmission based onZigbee application was researched. The maximum transmission distance was derived based on communication channel loss model and multi-path model. The effecting of multi-path on transmission distance was discussed. The effecting of Doppler shift was researched by speed of rocket sled and receiver position. Transmission speed and error rate of missile-borne tester was studied by Doppler effecting. The measure which reduced multi-path fading and Doppler effecting was gained. These can advance signal transmission quality and improve revamping of equipment.

The presence of mismatch between the presumed and actual target direction in spatial-temporal plane and the contamination of signal of interest (SOI) in training snapshots significantly degrades the performance of space-time adaptive processing (STAP). To solve the aforementioned problems, a robust STAP by employing the training snapshot selection and target direction correction is proposed in this paper. To solve the inaccurate estimation of clutter covariance matrix (CCM), training snapshots contaminated by target are eliminated using generalized inner products (GIP) statistics, and the more accurate CCM is obtained using the updated training snapshots. Then, an accurate steering vector (SV) estimation method is introduced using the prior knowledge of SOI. Finally, we obtain the proposed robust STAP weight with the novel CCM and the corrected target space-time SV. We carried out several computer simulations to validate the performance of our proposed method.

Station layout has a direct impact on localization precision for four-station TDOA (time difference of arrival) location system. In order to optimize the overall location precision of targets in certain area, genetic algorithm for station layout optimization is presented. GDOP is regarded as the measurement rule of location precision. Then the multi-object programming mathematical model of station layout optimization is built. The optimal solution is searched by genetic algorithm. Consequently, the optimal layout of station is obtained. The simulation provides the GDOP distribution of two station layouts. One is the initial station layout, and the other is the optimal station layout. The simulation results show that for the optimal station layout, the effect of improving the location precision is obvious, and also indicate the validity of genetic algorithm.

The mechanism of statement processing in FPGA is different from that in micro-processor. Statements are usually executed in parallel in FPGA, but they are done in series in processor. Moreover, "signal" and "variable" in FPGA are also executed differently. Because of conventional thought of series processing sequence in computer, mistakes are often made in analyzing processing sequence of FPGA statements. In this paper, some typical experiment cases are designed ingeniously to analyze the processing sequence of FPGA statements. Through experiment comparisons, some unexpected results are accquired. These experiment cases can demonstrate the sequence very clearly. A conclusion can be drawn that different processing sequences may lead to different results. So the processing sequence of FPGA statements is extremely important to signal processing. Therefore, more importance should be attached to the processing sequence of FPGA statements in FPGA digital system.

This paper introduces the design of the chassis speed algorithm for the Robocon2018 wheeled robot, and designs the motion algorithm of the wheel chassis for the Robocon2018 competition. Establish the coordinate system, through to the robot Chassis movement modelling analysis and based on the actual debugging situation, according to the decomposition and synthesis of vector velocity, the velocity projection value of three omnidirectional wheels is calculated by means of vector dot product, and then the velocity projection value is converted to STM32 PWM output to control the motor. It also proves the effectiveness and feasibility of the velocity algorithm to make the robot move according to the predetermined speed.

Voltage droop control is a common control strategy for multi-terminal HVDC transmission systems, while the traditional voltage droop control strategy has problems, such as large DC voltage fluctuations and unbalanced power distribution. To maintain the voltage stability of MMC-MTDC system and the power balance between the converter stations, an improved droop control strategy is proposed in this paper. The droop coefficient is designed by comparing the measured value of the multi-terminal direct-current voltage with the reference value of voltage. The four-terminal MMC-MTDC simulation model is built in PSCAD/EMTDC, and the proposed control strategy is simulated and verified under both transient and steady state conditions. The results show that the proposed control strategy can reduce the DC voltage deviation of MMC-MTDC system and improve the reliability and stability of the system. The correctness and effectiveness of the proposed method are verified.

Power transmission line monitoring systems are widely used in power grid in recent years. The communication bottleneck of the power transmission line monitoring systems focuses on the communication network of high definition video monitoring. This paper analyzes several communication solutions for the high definition video monitoring in power transmission line monitoring systems, including public wireless network, wireless mesh network, optical fiber network, and fiber-wireless hybrid network. Through technical comparison, this paper demonstrates that fiber-wireless hybrid network combines the advantages of optical fiber network and wireless mesh network, and it is the most suitable communication solution for power transmission line monitoring.

This article introduced a wearable ECG calculation system based on microprocessor cluster. The microprocessor cluster has the characteristics of low cost and low power consumption. This article proposes special hardware and software design methods for ECG calculation. In the experiment, a cluster of 48 Nuvoton nano120 processors was used to implement the computational tasks equivalent to the Intel i5-3317 single-core level. This cluster hardware requires only the size of a bank card in terms of volume and can be used for wearable devices.

The infrared readout circuit is a highly integrated circuit that integrates various functions into a single semiconductor chip. As the important part of readout circuit, the operational amplifier (OPA) decides the performance of the readout circuit. This paper describes a kind of OPA, which is used in infrared focal plane array (IRFPA) readout circuit structure based on the capacitive trans-impedance amplifier (CTIA) including the analysis and design of the OPA. Spectra is employed to simulate the circuit and obtain the results which is according with the designed objectives. The open-loop gain reaches 101 dB and the phase margin is 87°with the ICMR (input common-mode range) ranging from 201.6 mV to 4.01 V．

In order to solve the problem of low action accuracy due to changes of view angles, this paper investigates this issue based on deep learning and K-SVD sparse algorithm. Firstly, the paper extracts the feature maps from the different views by convolutional neural networks (CNN) and long short term memory (LSTM), and the extracted feature maps are the multi-views high-level features with semantic information. Secondly, the paper uses the K-SVD sparse algorithm to get the dictionaries corresponding to each views, the dictionaries have very good sparse representations for the features of the action. Then the softmax classifier is used for classification and recognition. The results show that the accuracy are 89.22% and 91.4% on IXMAS datasets and WVU datasets respectively.

The electromagnetic wave can lead to electrical equipment failure, which is really a serious problem to electrical power unit, which not only destroy the circuits but also may lead to fire. Therefore, This research focused on electromagnetic signal preprocessing and feature extraction based on wavelet transform. After building the model of electromagnetic waveform, the collecting signals of electrical spark affected by noise signals were processed, wavelet transform was used to filter the noise interference so that the features of electromagnetic waveform can be extracted. The result shows that the preprocessing of electromagnetic signal can achieve accurate feature parameter information and after extracting the features, which provide convenience to the further processing of electromagnetic signals.

This paper developed a coal-fired boiler modeling method based on CNN (convolutional Neural Network). In recent years, the deep learning using CNN has made remarkable achievements in image research field. This paper combined the image convolution method and the signal system convolution theory in coal-fired boiler modeling, which regards the DCS records as time series signal. This network is consisted of two convolutional layers which map the input to the feature map, followed by two fully connected layers to model the feature to the output. All the parameters in the network, including the convolution kernel parameter are optimized by minimizing the cost function. This model provided a good solution of modeling coal-fired boiler system with characters of time delay, highly nonlinear and multi-variable coupling.

An electrical distance calculation method considering operation mode is proposed. Based on line impedance, Phase-angle difference between buses is taken into account to characterize strength of electrical connections. Derivation of electrical distance considering operation mode is introduced. Comparing with traditional impedance electrical distance calculation method, rationality of this method was verified. Electrical distance of IEEE 39 example system is calculated. To explain effect of operating mode on the electrical distance, electrical zone division of power system under different operation modes are compared.

The passing neutral section scheme by using electronic switches instead of vacuum circuit breakers can shorten dead time of locomotives, and can eliminate the problem of locomotive deceleration. This paper constructed the traction power supply system model and the detailed main circuit model of Chinese standard EMU, including high voltage system and traction converter based on Matlab/Simulink. Then the scheme of using electronic switch is designed, and the influence of delay time required for the detection and action of the devices is considered. By comparing the simulation and measurement data, the accuracy of the model is verified, and analysed the transient response of passing neutral section when considering the delay time.

The particularity of lightning flashover failure of wind farm is analyzed, and it is pointed out that the formation mechanism of lightning overvoltage in wind farm collector system is different from that of power system distribution network. On this basis, the mechanism of lightning flashover failure of wind farm collector system is analyzed. The EMTP-RV software is used to simulate the typical lightning over-voltage formation and propagation process of the wind farm collector system. Results show that the fault mechanism of the lightning flashover fault system is analyzed. Finally, it is pointed out that the design scheme of the insulation system of the wind farm collection system should not directly copy the design scheme of the distribution network of the power system.

With the municipal tap water of a residential community in northern China as the research object, this study used UF-NF (ultrafiltration-nanofiltration) double-membrane separation technology to assemble and produce the drinking water device. The quality of tap water was compared with the quality of direct drinking water in pipelines. The removal effect of pollutants in water was analyzed, and the relationship between the operating pressure and pollutant removal was studied. It was verified that UF-NF combination is an ideal filtration and purification process for direct drinking water system.

At present, most of the electronic switches used have single function, raise voltage or reduce voltage, and also have step-up and step-down, it has the step-up and step-down function, but the circuit structures simple is not much. In this paper, an electronic switch which can replace the step-up and step-down circuits is designed. Three different levels of step-up, step-down and constant voltage are designed through voltage gain, the circuit solves the problem that the original small and medium power circuit can only step-up or can reduce the voltage, and realizes the function that the same circuit can not only boost the voltage but also realize the step-down function, and meets the requirement of continuous and adjustable power. Through the simulation and calculation results verify the feasibility and correctness of the design, and provide convenience for users, especially in the use of small and medium power. The voltage gain can be adjusted precisely according to the requirement, so that the voltage can reach the exact voltage value that can be adjusted continuously, thus shortening the engineering design cycle and the R & D process.

In this paper, an algorithm based on Inliers tracking statistics is proposed to solve the problem of motion-blur interference of RGB-D SLAM front-end pose estimation and back-end optimization. Firstly, the feature extraction and matching of the RGB image are carried out and the inliers is obtained by the RANSAC algorithm. Then, the blur image affected by the camera motion is removed by the tracking and statistics of the inliers quantity, and the camera position is solved by the nonlinear optimization method. Finally, the motion trajectory and the three-dimensional dense point cloud are plotted by and optimized global pose. Experimental results based on standard test set show that the algorithm based on Inliers tracking can improve the robustness and precision of SLAM system.

Aiming at the problem of short-term voltage interruption caused by the switching operation in distribution network, this paper studied the security loop closing technology for active distribution network based on synchronous information measurement. Firstly, the synchronous phasor information on both sides of the loop closing point was measured by the integrated distribution terminal unit (IDU), and the Thevenin equivalent parameter identification method based on the phasor measurement was proposed, improving the network equivalent accuracy. Secondly, the closing loop current calculation method based on identification parameters was proposed, which can effectively estimate the closing loop steady-state current and impulse current. Finally, an actual grid example was given to demonstrate the effectiveness of the proposed method.

As the deficiencies of the classifier algorithm commonly used in the partial discharge pattern recognition, this paper studied the application of RF in transformer partial discharge pattern recognition. Firstly, extracting the statistical characteristics from partial discharge test data to establish the discharge samples; Then, using ten folds method to judge the algorithm performance and compare the recognition accuracy of BP neural network, support vector machine, KNN, CART and RF algorithm. The results showed that the accuracy of the discharging pattern classifier basic on RF algorithm was the highest. The main differences between the different discharge modes were discussed by CART algorithm which composes RF.

The magnetic gear composite motor, which combines permanent magnet motor with magnetic gear together, can be used to reduce mechanical losses and thus obtain a high motor torque under the non-mechanical contact. By using the 2-dimensional finite-element analysis (2-D FEA) carried by using the FEA software EasiMotor, the motor distribution of magnetic field lines, the flux density and the corresponding Fourier analysis, the induced electromotive force, steady-state operation torque, cogging torque characteristics were analyzed respectively. The 2-D FEA is a valid tool used for analyzing the magnetic field and optimally designing the composite magnetic gear. The simulation results confirm the correctness and effectiveness of the proposed motor model.

Insulation faults in vacuum circuit breakers can produce physical phenomena such as visible sound, ultrasound, and electromagnetic waves. Through the real-time collection and analysis of the discharge sound during the internal insulation failure of the circuit breaker, the insulation state of the circuit breaker can be judged. This article proposes a method. The improved MFCC algorithm is used to extract the characteristic parameters of the discharge signal.The recognition of the flashover discharge sound signal is achieved by one-class SVM. The one-class SVM is constructed, so one-class SVM can be used to identify whether the signal is a surface discharge or not. The characteristic vectors of the audio signal of discharge have intrinsic similarity, and the distribution can be concentrated, which is significantly different from other abnormal sounds. The conclusion is verified by experimental data. The calculation results show that the it can effectively identify the insulation state of vacuum circuit breaker by the method of using of MFCC feature extraction based on Fisher criterion and one-class support vector machine.

This paper draw up the conditional evaluation strategy of grid-connected photovoltaic (PV) power generation stations based on the characterization of PV devices, and introduced the conditional evaluation index system includes performance and reliability of PV power generation station. This conditional statement evaluation method is based on both sides of the reliability and performance of PV devices, employ the availability, MRTBF, performance ration and power generation ability as the key evaluation index. In addition, using the operation data recorded by SCADA and recommended threshold values, in order to evaluation the operation conditional statement of grid-connected PV power generation station. Also, this paper proposed the performance degradation analysis method based on the hierarchical progression structure, and achieved the target of fast fixed position of fault PV devices. The firstly established conditional evaluation method is able to comprehensive evaluation the entirely operation statement of PV power generation station. This conditional statement evaluation method promotes the maintenance strategy of grid-connected PV power generation station, and guarantee the safe, stable and efficiency operation of stations. As a result, increase the benefits of operators of PV power generation stations and can be used to guide the PV power engineering.

With the rapid development of big data technology, more and more data are gradually applied to power distribution systems. Based on the fault analysis and positioning technology of distribution network based on big data, the fault is analyzed through the data collection analysis and state detection of distribution network, and the relevant positioning technology is optimized, so as to shorten the fault location time of distribution network, improve the fault analysis efficiency of distribution network and the accuracy of fault location.

When there is a single-phase fault appearing in an indirect grounding electric power system, in order to quickly locate the ground fault section. So here, a new method is proposed which is based on the oringinal localization algorithm. The method of phase section positioning is based on the zero mode of current's phase, when the fault is in this section, there is an opposition before and after the detection point. The simulation model was built by MATLAB, and the simulation conclusion are same as the theoretical proof.

This experiment was made of Porphyra haitanensis as raw material, extraction of pigment from Porphyra haitanensis by ultrasonic wave,the stability of the pigment was preliminarily studied, determine the best extractor and maximum absorption peak wavelength, the response surface analysis was used to optimize the four factors,the concentration of the extractant, the ratio of material to liquid, the temperature of extraction and the time of extraction.The results show that the optimum extraction agent for extraction of pigment from Porphyra haitanensis is ethanol,The maximum absorption wavelength is 580nm, the optimum extraction condition is 2% of the extractant concentration,the ratio of material to liquid is 1:50,the extraction temperature is 50°C,the extraction time is three hours.Under these conditions, the extraction rate of pigment from Porphyra haitanensis was 3.8%.

Based on Box-Behnken response surface method, it utilizes ultrasound-microwave synergistic effect to extract polysaccharide of Schisandra chinensis by taking the polysaccharide extraction ratio of fructus schisandra. On the basis of designing single factor experiment, it selects the extraction temperature, microwave power, ultrasonic wave power, feed liquid ratio and reaction time as the review factors and further determines the optimal extraction process by the response surface method: the extraction temperature is 65°C; the microwave power is 550W; the ultrasonic wave power is 60W; the reaction time is 15min; the feed liquid ratio is 1:25; under such condition, the polysaccharide extraction ratio is 13.23%.

A V-shaped linear piezoelectric motor was constructed and the output performances were valued by the output speed and thrust force. The effects of working conditions (i.e. the applied voltage and the preload) on the output performances were analyzed. Results showed that the effects of applied voltage and preload on the output speed and thrust force are not monotonic, which is different from the previous views. The related illustration and discussion are provided as useful suggestions for further investigations. Lastly, complex factors are discussed for the output performances and service behavior of linear piezoelectric motors.

This paper researches the impact of large-scale charging electric vehicles on power system with considering cascading trip events. Firstly, with the analysis of the relationship between the branches and the nodes in the power system after the branch with initial failure tripped, this paper proposes the corresponding equation that can reveal the relationship. Then, by combining that equation, this paper analysis the influences of large-scale electric vehicles when they access to the power system on the transmission grid. Finally, some examples are performed on IEEE-39 bus test system and verify the rationality of the analytical method in the paper.

In this paper, the pricing and transaction methods of wireless charging for electric vehicles are studied based on the two billing modes: transmitting side billing mode and receiving side billing mode. Two kinds of electric vehicle wireless charging service transaction methods are proposed: the power supplier directly trades with the user and the power supplier trades with the user through the intermediary. Aiming at the above two billing modes and trading modes, the corresponding pricing model and the price guiding strategy for charging mode selection for different charging users are proposed respectively, which provides a reference for the commercial operation billing mode of electric vehicle wireless charging.

When one loop line of the multi-circuit transmission lines on the same tower is in states of non-full-phase operation or asymmetric line-breaking faults, the zero-sequence direction of functioning loop lines is likely to maloperation due to zero-sequence voltage compensation. The multi-circuit transmission lines on the same tower with different voltage classes will induce the same zero-sequence voltage distribution trend as the fault line due to the mutual inductance between loop lines, and thus may conduct improper operation as well. This paper analyses the causes of maloperation of zero-sequence directional protection caused by non-full phase operation or line-breaking fault of multi-circuit lines on the same tower, and puts forward a method to prevent maloperation by extracting line status from station domain information. In the case of multi-circuit lines on the same tower with same voltage class, the crossing point of zero-sequence voltage of the line can be calculated and the zero-sequence voltage can be compensated in reverse to prevent maloperation. In the case of multi-circuit lines on the same tower with different voltage class, fault characteristics can be identified according to substation information and the zero-sequence direction protection can be automatically blocked. RTDS is used to simulate and verify the electrical characteristics, malfunction process and the effectiveness of prevention methods of multi-circuit lines on the same tower when a non-full-phase operation or abnormal line breakage occurs.

The power supply of micro grid is less stable than of conventional grid, and the harmonic pollution is more severe, aiming at this situation, in order to increase dynamic response performance, and the steady-state compensation accuracy of an active power filter (APF), a new design scheme of APF applied to AC micro grid is proposed. In this scheme, i_p −i_q algorithm is used to detect the harmonics, and the hysteresis control method is applied to control the compensation current, and the fuzzy adaptive PI controller is applied to maintain the DC-side voltage. An test platform using FPGA EP3C55F484C8N as the controller is established. The effectiveness and correctness of the proposed control method are verified in the simulation and experiment.

Aiming at reducing the shortcomings of existing ultrasonic electron discharge machining (EDM), a horizontal ultrasonic vibration EDM machining method is proposed. Orthogonal experiments of horizontal ultrasonic EDM were executed and compared with ordinary EDM, which indicated that the surface quality of parts and efficiency of the horizontal ultrasonic EDM method are improved. Experimental data results indicate that the horizontal ultrasonic EDM method has a positive role in guiding the actual application.

With the increase of the number of intelligent substation monitoring devices, traditional optical fiber communication network will result in increased complexity of the communication system and difficulty in system maintenance. On the base of the analysis of the communication requirements of substation monitoring and technical characteristics of different wireless communication technologies, this paper presents a multi-communication technologies hybrid networking solution to meet the communication requirements of substation monitoring. This communication solution combines the advantages of ZigBee and WLAN mesh network.

This paper proposes a weak signal detection technique based on Pseudo Wigner Ville Distribution (PWVD). The one-dimensional N-period sliding window is used to perform Pseudo Wigner transformation on the power signal data in the time domain direction, and analyze the PWVD regular on the frequency domain axis. Corresponding to extract PWVD on time domain, then analyze and accurately locates the weak signal changes, then performs the switching event detection. Finally, MATLAB is used to simulate the experiment, and the effectiveness of the proposed method is verified.

A new method for small current grounding system single-phase-to grounding fault location used transient component and Hilbert transform is proposed. The feeder terminal unit detects zero-mode current and line voltage signals, First, perform the Hilbert transform on the transient line voltage, Then multiply the line voltage after the Hilbert transform with the zero-mode current, defined the product as fault direction parameter. The FA master determines the line segment where the fault point is located based on the characteristics of the opposite polarity of the front and rear direction parameters of the fault point. The results of digital simulation prove that the proposed method has certain feasibility.

The microwave imager is based on remote sensing data acquisition system to conduct remote sensing observation of the earth. The sampling mode and sampling time affect the Microwave Imager. After analyzing the traditional remote sensing data acquisition system, when collecting multi-channel data, the sampling interval time and sampling start time can't be controlled, and multi-channel data acquisition can't be carried out in parallel. The new remote sensing data acquisition system uses fully parallel mode and FPGA to control sampling time and sampling interval. Simulation results and test results show that the remote sensing data acquisition system is multichannel and controllable.

The smart grid become a consensus for the development of power industry in the world, which can bring out the economic development of the world. Evaluation of the smart grid's development scientifically, systematically and objectively will beneficial to get better further development of smart grid construction. This paper creates an evaluation index system of smart grid construction development impact from four aspects, including technology influence, energy influence, environment influence and social influence and the four aspects contains 20 indicators. The indicator's weights are determined by AHP, then an empirically analysis is given by the grid development evaluation of China, America and European Union. The results show the relevant differences of the three countries, and some suggestions of China's smart grid construction in the future are also given.

With the improvement of the performance of the equipment, the requirement of power supply is improved, it puts forward different requirements on the suitability of power supply, electromagnetic compatibility, power density, output quality, efficiency, development cycle and so on, even in the future, the model of power supply in digital simulation of the whole equipment has already put forward the preliminary request, Therefore, the simulation research of power supply is imminent. Through the tireless efforts of power engineers, a variety of basic topology simulation model has been readily available, but given the optimal design and diversification of power supply requirements, a single basic topological model is obviously far from the degree of engineering applications. This paper, inspired by the basic modelling method, provides an effective method for the simulation research of the power system through the research of the topological mutual cascaded modelling.

In the past few years, implanted biomedical devices have been widely used in healthy and medical applications and wireless power transfer (WPT) techniques used in these devices have been become a research hot topic. The printed spiral coils (PSCs), which have characteristics of small volume, low cost, high precision and high-integration, are better suited for WPT system. It is noteworthy that mutual inductance value of PSCs is a significant parameter which can influence the transfer efficiency of WPT system. Considering the geometry of multilayer circular PSCs and the distance between two adjacent layers, the previous methods are not suitable for calculating the mutual inductance of multilayer circular PSCs. In this study, an approximate calculation formula of mutual inductance between two single-layer circular PSCs is presented based on the existing research. On this basis, the self-inductance values of double-layer circular PSCs are calculated by MATLAB, the calculation results are verified by the ANSYS Q3D simulation and measurement results.

The liquid medium can be atomized into small droplets and then it moves towards the reverse direction of the electric field force under the wind action, which can increase overall electrical potential energy of the system and realize the conversion of wind energy to the electric energy. In this paper, multi injection needle mesh electrode is taken in the electrostatic wind power generation system as the research object. Based on the ANSYS simulation platform, electric field distribution and the influence of electric field intensity on spray effect at injection needle in different structure like quadrangular, rhombic, circular and hexagonal high pressure electrodes are studied. The results show that the voltage level of discharge terminal in circular electrode structure is significantly higher than that of the other electrode structures and voltage level is needed for multiple jets significantly lower than the other electrode structures.

The strength reliability of a solid rocket motor shell is analyzed. The maximum entropy test method, which is based on information theory, improves the test entropy of a single test sample by reducing the load capacity of the engine shell design under the condition of keeping the load of the engine housing unchanged, so that the total sample size that is required for the test is greatly reduced. The results show that test method of maximum entropy can solve the problem of shell strength reliability assessment when the engine sample size is small. This method can also be applied to small sample reliability assessment in other fields.

After the micro-grid is connected to the distribution network, the unidirectional power flow in the original network is transformed into a bidirectional flow, and the original protection device cannot meet the current safe operation of the micro-grid. Due to the complex structure of the micro-network, it is necessary to study the fault location and identification methods in the network when a fault occurs.In this paper, in order to solve the fault section location problem, the phase-to-phase short circuit model of the micro-grid under the state of distributed power grid-connected faults was established, and the positive sequence currents amplitude at the upstream and downstream of the fault point are extracted using the symmetrical component method.The fault section is determined by the amplitude of the positive sequence current at the adjacent detection point on the fault branch. It solves the problem of increasing the difficulty of fault detection due to changes in the access of conventional power electronic devices and changes in short circuit types. The distribution network model was built by MATLAB to simulate and verify the feasibility of fault-based steady-state component section positioning method.

Two layer lattice-type metamaterial unit is loaded above a microstrip antenna, gathering electromagnetic wave by using the zero refraction index effect. The π -type metamaterial unit is etched on a substrate, and the band gap is wored out for restraining the backward wave. Simulation tests are carried out to two methods, respectively. Finally two methods are combined for designing a high directivity antenna, and the effeccts of the distance between the covering layer and the antenna are dicusseed. Comparing the simulatted and the real test results, we verified the method and the theory. We can see that the gain of the newly-designed microstrip antenna has achieved by 8.94dB and the directivity factor gained an relative increase of by 49.08%.

In regard to the balance management for high capacity Lithium-ion battery packs in space, an active balance circuit based on the topology of multi-winding transformer is proposed in the article. The circuit can control the magnitude of the balance current by fixed duty cycle control, to achieve charge balance function. The circuit can effectively improve the balance speed of the high-capacity battery packs, meeting the requirement of balance function and reducing the energy loss of the battery packs, Meanwhile, increasing the service life of the battery packs. The novel balance system can realize modular and scalable. A Simulink model was built for the program. The simulation results prove the correctness and effectiveness of the circuit.

Private Comparison (PC) is an extension of Yao's millionaire problem: two millionaires want to know if their wealth is equal, but they don't want to reveal their specific wealth. In classical cryptography, this problem has been well studied. However, the security issues of these protocols are based on computational complexity assumptions, which means they cannot resist powerful quantum computing. In this paper, a quantum private comparison of equality with better performance in resisting outside attack is proposed based on two parties. Compared with the previous protocol, our protocol greatly reduce the total probability of obtaining the wrong result. And it also can compare successfully even if the two hash value string are short and close. Meanwhile, our protocol can be implemented easily without using entanglement, joint measurements and quantum memory and so on. Finally, we show that our protocol can be secure against the attacks from both the outside eavesdroppers and the inside participants.

Integration of renewable energy source (RES) increases the volatility and uncertainty of active distribution systems while the limited line capacity hampers the accommodation of RES. Soft normally open point (SNOP) has the capability to control the power flow between distribution feeders accurately which can mitigate line congestion. SNOP is an effective flexibility resource in active distribution systems. However, currently it is impossible to replace all traditional tie switch by the SNOP considering the high cost of SNOP. In this paper, a coordinated control strategy considering the coexistence of tie switch and SNOP is proposed, in which a bi-level model is built. An index weighing the static insecurity probability is defined as the bridge between the two layers of the bi-level model. By solving the mixed integer nonlinear programming problem, the coordination between tie switch and SNOP is realized accounting for different characteristics of the two types of devices. Simulation results on a 33-bus test system demonstrate the effectiveness of the coordinated control strategy.

With a large proportion of renewable energy sources integrated through the power electronics interface, power systems are challenged with decreased inertia threatening the system stability. Synthetic inertia control aims to emulate inertial response of various available resources. A wide-area synthetic inertia control strategy for multiple resources is proposed in this paper. The offshore wind farm composed of DFIG wind turbines is interconnected by the VSC-HVDC link. Synchronous condensers are installed to improve the system dynamic characteristics. Synthetic inertia control is designed for DFIG wind turbines, VSC-HVDC link and synchronous condensers, respectively. Wide-area frequency signal is employed to overcome the limitation of local signal. Primary frequency control support by DFIG wind turbines is incorporated to improve the control effect of the strategy. Simulation results on New England 39-bus system verify the effectiveness of the proposed wide-area synthetic inertia control strategy.

With the wide application of the internet and rapid development of the information technology, the scale of the internet data center power network is growing larger and larger. Some of the troubles in the internet data center (IDC) power network may cause extensive service out of service or even collapse. However, without considering the characteristics of the IDC power network, the important node identification methods for the IDC power network based on graph mainly focus on the graph structure itself. Since a large number of automatic switching equipment such as ATS, STS and loop switch have been used in IDC, when the electrical fault occurs, the load will be automatically migrated to the adjacent electrical equipment, which may lead to overloading or even tripping. So the failure is extended. So how can we efficiently and effectively capture the fault evolution mechanism of the IDC power network? How do we go about identifying the vulnerable nodes causing the collapse of the IDC power network.

In this article, we propose DCPNFEM, a novel fault evolution model for the IDC power networks, as well as a fitting algorithm, BCBL, which can solve the proposed problems. Our algorithms have the following properties: (a) Intuitively: it detects fault evolution mechanism, such as power load migration, electrical equipment tripping, and so on; (b) Timely: our method is based on the real-time power loads; (c) General: our algorithms are general and practical, which can be used in various power network topologies, including data center infrastructures from tier1 to tier4.

Extensive experiments on a real IDC power network demonstrate that some particular nodes' failure can lead to the power network crash under DCPNFEM. And BCBL algorithm outperforms better accuracy and speed than many other algorithms.

Goaf water is a major hidden danger affecting the production safety of coal mines. This paper describes a study on the application of transient electromagnetic technology for detection of goaf water in Tianli-Tianxin Coal Mine, which may play a reference role for the detection of goaf water in similar mined areas.

Here, The new arbitrated quantum signature (AQS) protocol assisted by asymmetric key based on qubit block encryption algorithm is given. Interestingly, our protocol with the asymmetric key can be easily extended to multi-party verification. Unlike all previous quantum works on arbitrated quantum signature, the encryption algorithm of the pre-sented protocol is qubit block encryption. Since, the proposed protocol has a better performance in resisting existential forgery attack. In addi-tion, with the help of the arbitrator, it can be proved that our protocol is secure.

This paper designs combined cooling heating and power systems with wind power generation (CCHP-Wind) system, and establishes the optimal operation model of the system. The optimal operation mode of matrix modeling is set up and the comprehensive indicator including energy, environment and economy index is used as the measurement standard compared with the traditional power determined by heat (FHL) mode and heat determined by power (FEL) mode. Establishing the optimization operation mathematical model in system, sequential quadratic programming methods and genetics algorithm are used to solve the optimization model, determine the optimal operation mode of the system. Taking a hotel in Wuhan as the research object, the typical days of the four seasons of the year are selected, according to the different cooling heating and power demands and the wind energy sources of four seasons, the CCHP-Wind system optimal operation is empirically analyzed. The results show that the set matrix optimization operation mode compared with the traditional operation mode can reasonably distribute the energy flow of the system, satisfying the demands of the system and effectively avoid energy waste.

With the increasing proportion of Hydro generator units in the whole power grid and its aging infrastructure, it becomes increasingly important hot topic for our next generation smart grid to complement a real-time fault diagnosis in Hydroelectric Generators. In this paper, we propose a road-map towards this issue. To this end, Variational Mode Decomposition method and other signal processing algorithms, such as Multi-dimension Permutation Entropy and fuzzy C-means clustering algorithm and so on, are developed and power line communication technique is used. Computer simulations results show that our proposed diagnostics solutions successfully empower Hydroelectric Generators to independently predict and identify the three different most commonly faults.

The security of a noise-induced optical encryption scheme with two dimensional keys is examined by a series of statistical analysis. We introduce the cross correlation function (CCF) and mutual information (MI) approach to estimate the time-delay information, which is considered as the most important physical key in the secure strategy. Subsequently, the other key can be cracked by using the independent component analysis (ICA) method. Meanwhile, the plaintext can be extracted with a small deviation.

In this paper, the ABAQUS dynamic display analysis method is used to realize the quasi-static analysis of the welding nail. The correctness of the finite element model is verified by comparing with the existing experiments. The finite element simulation calculated four different nail lengths h_s, and the calculated simulation values were in good agreement with the experimental values. In the case of the failure mode, when the welding nail is too short and the length-to-diameter ratio of the welding nail is less than 5.92, the whole of the welding nail together with the broken concrete in the surrounding area is pulled out, and when the aspect ratio satisfies certain requirements, the welding nail is generated. Necking, the concrete slab is not broken, and the ultimate tensile bearing capacity is relatively close.

In this study, the ground-loss resistances of very low frequency (VLF) monopole antennas are considered. A novel method of obtaining solutions of the magnetic field and electric field losses for the earth system is outlined. The equivalent conductivity of the ground system is obtained using the parallel relationship between the nature surface and the ground wires. This provides significant convenience for the calculation of the ground loss and the design of the ground system. Because an equivalent ground plane is used, a unique solution of the ground loss resistances is achieved by using the integral of the equivalent unit circles. The proposed method is verified by comparing the numerical integral method and full-wave simulations. The numerical results and the effects of the VLF monopole antenna configurations on the loss resistances for different monopole heights and artificial-ground-plane installations are discussed.

This paper presents a VHF dual-band cross-coupled voltage VCO with push-push structure. This is achieved by using the push-push structure and the binary-weighted capacitor. The circuit has been implemented in TSMC 90nm CMOS process with a core area about 800μm ×600μm. The measured fundamental and push-push output phase noise at 10MHz is-108.57 dBc/Hz and-98.43 dBc/Hz, with the tuning range covers 26.38 GHz～28.15 GHz and 52.76 GHz～56.30 GHz.

In order to obtain the temperature and humidity information of the Test section in the low-speed flue gas wind tunnel in real time, a low-power wind tunnel temperature and humidity data acquisition system based on CAN/SimpliciTI hybrid network is designed. The CAN network is used as the main network, while the SimpliciTI low-power wireless sensor network as the sub-network. The terminal ED nodes of sub-network acquire the ambient temperature and humidity information of the location and then transmit them to the gateway node by wireless mode. In the gateway node，the SimpliciTI messages are converted into CAN messages, and finally, they are delivered to the main network. The host computer communicates with the gateway node through the CANalyst-II protocol analyzer, and finally gets the temperature and humidity information of each ED terminal. Compared with the traditional bus type communication system, the system has the advantages of less wiring, simple network hardware, low power consumption, and convenient maintenance.

Article have summarized application sun energy in regenerative energy generate electricity the related content of systematic importance. On this foundation, have led into single very type three-phase current type sun energy and net inverter systematic model. With the sampling sequence theoretical and fast Fourier of frequency domain, it is the regular method that describes control strategy specificly to alternate technology with I interval ( 0 ～ 1/3 π ), for in I interval 7 alternate mould form in, analyse single very type current type sun energy specificly and net inverter system the realization of control method have gone on analyse comparatively in detail. The analog result of computer has shown the consistency of emulation and theory.

In order to find out the fundamental cause of terminal breakdown of a porcelain-covered oil-filled cable for a 220 kV cable line, a theoretical model of particle phase flow was adopted to analyze the breakdown mechanism by means of finite element simulation. The results show that the breakdown of cable terminal was caused by the flocculation produced by the aging of the silicone oil filled material. When the critical state of the flocculation was reached, the grounding channel was formed along the stress cone, and the electric field in the cable terminal was distorted. The electric field intensity of cable insulation had reach 8.25kV/mm, which was 13.4 times that of normal operation. Under the combined action of high electric field and moisture, many water tree had appear on the outer surface of the cable insulation layer, which leads to the breakdown of the cable insulation layer on the top of the stress cone. The research results can provide an important reference for the design and maintenance of HV and UHV cable termination.

Based on the practical characteristics of the basic course of electronic technology, a new method of optimizing the circuit by using the parameters scanning function of PSpice simulation technology is proposed, which is to perform basic transient scanning on the circuit to meet the basic functions of the amplifying circuit. After discovering the unreasonable technical parameters, the parameters of the circuit are scanned and modified. After correcting the incorrect parameters, the optimized analyze design module is used to optimize the circuit design. The optimal design process and simulation results of the voltage-divided bias amplifier circuit by this method are presented. The experimental results show that the optimal design of the amplifying circuit can not only meet the performance parameters required by the constraints and target conditions but also reduce the number of optimization iterations and simulation execution by adjusting the performance specifications of the circuit, thus improving efficiency and accuracy of the optimization design. At the same time, it also verifies the effectiveness and feasibility of optimizing the circuit and design through the simulation.

Based on the analysis of the conventional bandgap reference circuitry and the current IC of reference voltage source in the design of low voltage low power consumption and high power supply rejection ratio, a bandgap voltage reference with startup circuit and current compensation circuit is presented. It has a low temperature coefficient(<20ppm/℃)，a temperature coefficient of 9.3ppm/℃ in the temperature range from-50℃ to 125℃, and a PSRR of-64dB at low frequency,which meets the requirements of bandgap reference for low voltage, low power and high PSRR.

This paper analyzes the potential influence in Chinese electricity market due to the reform and access of the electricity spot market. On this occasion, a deep learning based model for load forecasting is proposed to improve the market operator's precise scheduling level and assist power retailers in managing bid strategies. Long-Short Term Memory (LSTM) unit is used to modeling, which is one of the most popular techniques of deep learning. In addition, historical power load data and meteorological data of Suzhou and Lianyungang in China from January 2015 to December 2017 are used for the study to training and evaluate forecasting model. As a result, this paper shows the compare results with exiting machine algorithm for load forecasting.