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As a non-destructive insulation diagnostic technique, the polarization spectrum method based on return voltage measurement has been employed to assess the state of insulation of the transformer. But how does the moisture content affect the parameters of RVM is not clear. In this paper, the effect of moisture content on the parameters of return voltage is studied based on experiments. The result shows that maximum value of return voltage (Urmax) and initial slope (Si) increase with the increase of moisture content in second-order function, while the central time constant (tcdom) decreases with the increase of moisture content in second-order function. The central time constant varies strongly with the change of moisture constant, so it is considered as a reliable indicator to evaluate the moisture level in oil-paper insulation system of transformer.

Return voltage diagnostic method is an effective method of non-destructive diagnosis in transformer insulating state. The current study is that through experiments get polarization spectrum to analysis the transformer insulating state, but not yet carried out the influence of various factors to the experimental results. So, based on the Debye model and specific parameters comes from one equivalent model of the actual transformer, this paper using RVM methods to simulation analysis maximum return voltage and dominant time constant under different factors. Simulation results show that the diagnostic methods that combine maximum return voltage value with dominant time constant can preferably reflect the transformer insulation state.

To assess the oil-paper insulation of transformer, it is necessary to establish the equivalent circuit for it regardless of using the time domain methods or frequency domain methods. Based on the principle of dielectric polarization, the extended Debye model is always adopted for the equivalent circuit of oil-paper insulation in transformer in most cases; however, it is usually difficult to determine the number of relaxation mechanisms in the model. This paper presents a method to determine it by the time domain dielectric spectra, namely, conduct differential operation for the depolarizing current of transformer’s oil-paper insulation to obtain the time domain dielectric spectra, and the number of spectrum peaks is equal to that of relaxation mechanisms. Thereby, the extended Debye model of the equivalent circuit of the oil-paper insulation of transformer can be built. This paper describes the analytical procedures of the time domain dielectric spectra method in detail and presents examples to validate its feasibility and rationality in determining the equivalent circuit model of transformer’s oil-paper insulation.

An implementation framework of stepped-frequency LFM (SF-LFM) radar echoes simulator is presented in the paper based on the decomposition and calculation of SF-LFM radar echoes of a moving target. The proposed method can be implemented conveniently with direct digital synthesis (DDS) logic resource. The feasibility of this resolution is verified with computer and semi-physical simulations experiments.

Super capacitor, as a new type of power storage device, has been applied to various fields. This paper divides composite electrode materials of super capacitor into three main types. For each type, this paper analyses its performance, advantages and prospect. At last, a conclusion is drawn that it is a tendency to apply composite electrode materials to use for better performance capacitors.

Distribution and power transformer is the essential part of electrical power transmission system. Abnormalities occur at the transformer can be interpreted and analysed to get the cause of faults, thus it can be further studied for monitoring ageing and condition of the transformer. A lot of studies have been done to detect as many abnormalities that can possibly arise in a transformer. For inexperienced user, it can be a bit of overwhelming to choose which studies that they can refer to. Numerous techniques and methods has been used for transformer monitoring till date and still being improved which includes: Common Electrical Tests, Power and Dissipation Factor Measurement, Partial Discharge (PD) Analysis, Frequency Response Analysis (FRA), Dielectric Response Analysis (DRA), Dissolved Gas Analysis (DGA), Dielectric Breakdown Voltage, Oil Resistivity, and Karl Fischer Titration. These techniques and methods are developed to monitor and analyse the common part of transformer which are winding, core, bushing, insulation oil, and insulation paper. This paper reviews the current improved techniques and methods in transformer monitoring according to the technology, accuracy, complexity, and cost for the past five years. A few methods and techniques can be appointed to each of classified user as a beginner, intermediate and competent. Finally, this paper suggests more improvement to be studied on the existing established methods. Some of the techniques can be combined to create a better accuracy and efficiency for fault identification, ageing estimation and condition monitoring.

The paper is focused on the ionization current measurement in the cylinder SI engine during an engine cycle. Briefly describes the problems and lists reference sources, which are several possible ways of measuring the ionization current during the working cycle. Paper also provides information regarding the proposed scheme of measuring devices and mentions functional test equipment.

Distribution transformer in Malaysian electricity network is categorized as major element on delivering electricity throughout the nation. Advanced diagnostic tools are used to monitor any technical problem of transformer to sustain its capability in the long run. One type of it which is currently being used in worldwide is Frequency Response Analysis (FRA). The reliability from this method is proven worldwide in diagnosing transformer condition especially a mechanical movement. FRA technique is done by comparing the response result in transformer initial condition to its current condition. The interpretation of transformer condition from the response is based on frequency sub-bands. Each frequency sub-bands are indicating any movement parts of transformer and electrical faults. Currently, there are three worldwide standards established for interpreting the FRA results but both of them are different in frequency sub-bands range. Up to now, there are no research papers comparing the fault detection capabilities from frequency sub-bands range for both standards. In this paper, comparative study is done to visualize and interpret the capabilities from three standards (IEEE Std C57.149 2012, DL/T911-2004 and Cigre WG A2/26); by focus on the frequency sub-bands range.

Power delivered to consumer from utilities is susceptible to power quality problems. The most common power quality problems are voltage sag. Modern equipment nowadays are prone to problems associated with voltage sag. Such problems can be apprehended by several mitigation methods. This paper will discuss voltage sag mitigation method by eliminating the injection transformer in ordinary Dynamic Voltage Restorer (DVR) and applying Single Phase Matrix Converter (SPMC) in a single phase DVR topologies. The objective of this paper is to investigate the potential mitigation method without the injection transformer in the DVR topology. DVR circuit will be constructed and simulated using MATLAB/SIMULINK software. It is hoped that the result of this work will provide a simpler mitigation technique where existing DVR topology can be constructed with less component that provides unnecessary losses in the DVR itself.IndexTerms—Injection Transformer, DVR, SPMC, MATLAB/SIMULINK.

The interests in multiphase (more than three) system are escalating recently especially in the motor drive applications. Thus, this paper introduces the graphical phasor diagram method in designing the multiphase transformer connection. The proposed method eases the design process of the static multiphase transformer that produces multiphase output from the standard three phase input. The transformer connection was simulated in ANSYS Maxwell and the multiphase waveform with appropriate phase angle was obtained. The design of five-phase transformer using graphical phasor and simulation results from the finite elements software are presented in this paper.

Exhaust noise is one of the noise pollution to the environment and it will cause interference that may harm the activity or balance of human. A muffler is designed to minimize transmission caused by exhaust gases. In this paper, the principle of transfer matrix method is used to analyze the transmission loss. The method is used for developed source code programming to predict muffler performance. The result from programming show excellent agreement with the previous established research paper. This programming is applied for baffle effect to determine transmission loss.

The low conductivity material such as cancellous bone, cortical bone tissue and soft tissue is the mainly content in the spine. And the improvements on distinguishing the low conductivity material can make a contribution to the spinal fixation surgery process, and protect the patient from spine incident trauma injury during internal fixation prosthetics with implanting pedicle screws. As a result the low conductivity material detection is of great importance in biomedicine study. According to the magnetic property difference of different low conductivity material, an eddy current detection method based on GMR sensor which is proposed in this paper. Compared with coil sensor in traditional non-contact detecting system, GMR sensors have advantages of higher sensitivity, higher precision, better linearity and better stability. Based on this methods, this paper introduces a low conductivity material detection probe. Several experiments indicate that this detection method can detect the low conductivity material NaCl solution with conductivity of 0.128 S/m, whose electrical conductivity matches that of biological tissue. This results lay a solid foundation on the biological tissue detection research.

In this paper, a new method using wavelet packet energy spectrum to identify transformer inrush and internal fault current was proposed. Wavelet packet transform respectively decomposed inrush and fault current, then calculated the energy of each frequency band of decomposed signal. Finally, the conclusion showed that the energy of internal fault in high frequency band is much less than that of inrush. The difference was quantified and it could be observed intuitively. Through extensive simulations, this paper proves that the method in terms of identifying transformer inrush is accurate and effective.

In this paper, the basis function of TDCS system (Transform Domain Communication System) is used to design cognitive radar transmitter waveform. Based on the noise environment, the waveform can be adjusted adaptively. Then after clipping to reduce the PAPR (Peak to Average Power Ratio) of radar echo signal, the obtained signal is used as the next launch of the radar signal. The cognitive radar transmitter requires a nonlinear waveform to improve the efficiency of radar transmitter power amplifier, so reducing the PAPR of signal is essential. This paper presents the gray complementary sequence is applied to TDCS communication systems, and then it needs to reduce PAPR of signals by clipping. Proven, PAPR of the transmitted signal is maintained at about 3.25dB, and the signal has a low probability of intercept, high anti-interference ability and distant target detection range.

According to the relay protection rules, 110kV bus and 220kV bus and above, should be installed special bus protection. This paper do a separate research on bus coupler charging protection from the aspects of bus protection principle and logic of action. It was pointed out that the necessity of blocking differential protection in the process of coupling charging and the new problem of blocking differential protection. This paper puts forward improved bus charging protection after research the processing methods of different relay protection manufacturers, and it improves the reliability of bus coupler charging protection

This paper proposes a convenient and safe method for removing extra matters on overhead lines by distantly irradiating the extra matters with high-energy laser beam. Theoretical study and field experiments on the feasibility of this method were carried out according to the thermal properties of the main components of overhead lines and common extra matters on them. Results show that infrared laser is a better choice to be used to remove the extra matters than ultraviolet and visible laser lights. Experimental results also indicate that there is a large feasible scope of laser power density in which common extra matters can be efficiently removed while the conductors and grounding lines get no harm. Moreover, preliminary design of the laser removing system is given in this paper for practical application.

This paper relates to a high reliable communication method for the terminal of a networked and distributed power supply system. Terminal refers to the realization of two-way communication between high voltage source of distributed power supply and laden multiple electrical appliances. Due to the characteristics of long distance, complex electromagnetic environment and small amount of communication information between the voltage source and the electrical appliance, this paper designs a new kind of high reliable communication method along with high-voltage transmission, narrow-banded and single-ended synchronous [1,2,8]. Under the condition of satisfying the communication capacity and reliability, this method has been successfully applied to the city network and LED street lamp management system with the advantage of simple circuit design and inexpensive manufacturing cost.

The main factors influencing the output wavelength of semiconductor are drift of working temperature and changes of working current. Therefore, the key technology of semiconductor frequency stabilization is to detect frequency shifts and convert the shifts into electrical signal, then feedback control the working current and the temperature in order to ensure that the output frequency basically remains unchanged. So, a laser wavelength measuring system based on DSP is designed in this paper. The measurement theory of the system and the design of hardware are given in this paper. The system is composed of DSP, optical grating, CCD and so on. This measurement method introduced in this paper makes the measurement intelligent and has high degree of accuracy of measurement.

The paper researches on the offset error of self-triggering pulsed mini laser radar. It theoretically analyzes the variation of space charge region of PN junction in receiving photodiode. The variation value is affected by the different incident light power. One of conclusion is the laser pulse time-of-flight affected by the variation of incident light power. Another conclusion is the laser pulse width affected by the variation of incident light power as well. The paper proposes the basic equations to describe this phenomenon. In addition, the new designed experimental devices are used to prove that the theoretical analysis is true. This new system can effectively solve the offset error problems, and the negatively impact of offset error will be eliminated on the receiver of self-triggering pulsed mini laser radar system.

In this paper we designed a 5.8GHZ microstrip antenna whose relative bandwidth is 3.77% and return loss is-36.941dB. It meets the needs of RFID systems.Besides, the resonant frequency of the antennas is reduced to 5.2GHZ, after adding the “I” ring resonator. Also, the paper shows that the other performance of the antenna still meet the RFID system requirements. It is 47.1% of the original size after adjusting the resonant frequency of the antenna to 5. 8GHz.

EVT (electronic voltage transformer) is one of the key devices of the intelligent substation. This paper introduces the basic principles of EVT error tests. By analyzing the test environment of EVT with GIS structure, this paper establishes the high-voltage side equivalent circuit for the field EVT calibration methods and proposes to carry out field boost for the EVT with GIS structure, which could effectively improve the field calibration efficiency of EVT. Based on the research on the complex field environment of EVT, this paper puts forward the field test methods of EVT with AIS structure and the results show the effectiveness and correctness of this study.

The capacitor voltage balance of the sub-module is the necessary condition for normal operation of the STATCOM. In this paper, the topology and mathematical model of the STATCOM are introduced briefly, the instantaneous power characteristic and capacitor voltage balance principle are studied in detailed, and the balance control algorithm for real project is put forward, in this algorithm, the modified reference wave is got by delay the phase modulation wave by 90°, rather than calculate the sine value of the PLL phase. So the algorithm in this paper can realize in sub-module in real project, the simulation result and real project validated its efficient.

Vibration in any rotating machines is due to faults like misalignment, unbalance, crack, mechanical looseness etc. Identification of these faults in rotor systems, model and vibration signal based methods are used. Signal processing techniques such as Fast Fourier Transform (FFT), Short-Time Fourier Transform (STFT), Wigner-Ville Distribution (WVD) and Wavelet Transform (WT) are applied to vibration data for faults identification. The intent of the paper is to present a review and summarize the recent research and developments performed in condition monitoring of rotor system with the purpose of rotor faults detection. In present paper discuss the different signal processing techniques applied for fault diagnosis. Vibration response measurement has given information concerning any fault within a rotating machine and many of the methods utilizing this technique are reviewed. A detail review of the subject of fault diagnosis in rotating machinery is presented.

This paper briefly introduced the main linear damages in the network layer of electric power Optical Transmission Network which contains fiber loss, chromatic dispersion and polarization mode dispersion. Based on the engineering practice in the application of power system, this paper studied the loss in the optical fiber cable line. The paper also studied chromatic dispersion and polarization mode dispersion. The calculation models were concluded and used for simulation verification. Each model can be used to power OTN engineering design.

Cylinder is a common object and used in logistics industry, such as liquid container like wine. The performance of tags that are used on these objects declines, especially the read range and the radiation pattern of the tag. In this paper, a type of UHF tag antenna directly mountable on the cylinder surface. In order to reduce the impact of the deformation, the tag is designed with meander-line but not symmetrical. Antenna is combined with T-matching network to ensure good impedance matching. Compared with the basic dipole antenna tag both cylinder and plane surface, we can get the prominent feature of the tag proposed in this paper.

This paper discusses the use of Baum-Liu-Tesche (BLT) equation for analyzing and calculating the propagation and load responses of transmission-line networks in frequency domain and time domain. The derivation and each parameters of BLT equation is introduced, and using BLT equation, two examples of specific coaxial cable networks are established, and the propagation and responses of networks are analyzed and calculated. The responses of networks terminals are measurement, and calculation results and measurement results are compared. The results show the excellent agreement between measurement and calculation results. The study results of this paper can be used for cable networks design and protection against EMP.

This paper emphasizes the wireless relaying performance analysis in interference environment. We will analyze the main performance metrics such as outage and error probability of the communication system in interference environment, and will make some simulation to demonstrate the result of theory analysis. In relay transmission system, either two relaying or multiple relaying, its basic principles are based on the two relaying system. In this paper, the wireless relay system performance in the interference environment will be analyzed and simulated on the basis of previous studies.

Retracted paper: Galvanic coupling method has been observed to be the best method for data transmission in intra-body communication, which is proposed by Zimmerman in 1995. With the increasing transmission requirements and the development of optical fiber communication, a high speed data transmission system is required and it is possible to design an apparatus to realize the electro optic conversion. In this paper, the characteristics of the intra-body communication system are introduced. Principles and structures of the electro-optic modulation methods for intra-body communication are reviewed. Internal and external modulation methods are introduced and discussed. A system of the electro-optic and acousto-optic modulation are recommended for the intra-body communication system and discussed.

Distribution transformer is an important device in the power system, once its failure can cause power outages. According to statistics, 70% -80% of the transformer accident was caused by a short circuit between the transformer turns. In this paper, the ground current of transformer core as the signal source, using Kalman filter techniques to approximate the measured signal, obtained state transition parameters of the prediction signal that most approximate the signal measured , Generated the inter-turn short circuit fault diagnostic parameters, based on the range of parameters to achieve the transformer inter-turn short circuits fault diagnosis. To verify this method, this paper design experiment, the results prove the validity and feasibility of the methods for fault diagnosis.

Distribution transformer is an important device in the power supply system, once its failure can cause power outages. According to statistics, 70% -80% of the transformer accident was caused by a short circuit between the transformer turns. Based on the large number of experimental data analysis and processing, a new inter-turn short circuit transformer diagnostic methods is proposed. In this paper, the ground current of transformer core as the signal source, Using wavelet multi-resolution technology the signal wavelet multiscale decomposition, the decomposition of different signals of the same scale, get the high frequency components of the signal, achieve short-circuit fault diagnosis between transformer winding turns by comparing the number of the high-frequency component contained in different signals in the decomposition of the same scale. To illustrate the effectiveness of the method, the paper through a series of experiments and data processing, verify the effectiveness and feasibility of the method.

This paper takes DSP2812 as the core to develop the new reactive power compensation controller, realized the reactive power compensation, detection of the electricity distribution network information, and through mobile phone short message module TC35 to send mobile phone SMS information, remote control compensation capacitor, configuration parameters. The design has the characteristics of flexible and reliable, convenient and practical. This paper analyses the software and hardware structure of controller in detail, and the hardware principle and circuit and the software block diagram of the controller. Controller adopts the integrated control, to maximize the use of compensation equipment to improve the power quality of power grid.

The variable reactor (L) and capacitor capacity (C) of the passive dynamic harmonic filter have influence on the filtering performance. The method of the L and C selecting is advanced in this paper. To select the optimal C, two conditions about the reactive power compensation and harmonic filtering need to satisfy. To analyze L, T-type equivalent circuit is constructed in this paper. With the optimized L and C of the passive dynamic harmonic filter, the harmonic filtering and the reactive power compensation are finished reliably.

This paper presents a novel soft switching topology and its control method applied on three-phase current source inverter. The main switch transistors of the inverter can be achieved in soft switching on the current pass-through step, which can reduce switch stress and improve efficiency. The soft switching circuit consists of two auxiliary switch transistors and some passive devices, such as inductor, capacitor and diode. It has many advantages as follows, simple control, fewer devices, high reliability, and so on. This paper analyzes the principle of soft switching circuit, and simulate by using the current space vector control method with MATLAB. The simulation results demonstrate the feasibility of the method.

In order to realize the integration of electronic circuits and avoid the electromagnetic interference between mutual inductance components and periphery circuit, the paper put forward a new kind of coupling element-mutual capacitance components, which were dual with mutual inductance components, according to the duality principle and the gyrator application theory. First of all, the paper used the basic electrical components-operational amplifier, resistance and capacitor to set up the circuit implementation model of mutual capacitance component, and then selected device parameters to execute theory calculation. On the basis of the previous step, a simulation software-PSpice, was used to simulate the model. Finally, comparison of two different groups of simulation data showed the correctness of the circuit model and the feasibility of the mutual capacitance component.

In practical applications,the solar cell is always used in the form of Solar Cell Module which consist of two or more solar cells connected in series or parallel. Therefore, the study of the Solar Cell Module reliability screening has more practical significance than the single solar cell. Based on the previousEn-InModel, this paper analyzes the Solar Cell Module consists of two solar cells connected in different patternsthe series and the parallel, and obtains the corresponding noise parameters. Then, the concept of connection matrix C is put forward. In the end, this paper gives the corresponding conclusions by comparing the measurement results. The results of dual solar cells network will be the basis for future research of the Solar Cell Module reliability screening.

There have been recent research interests in obtaining an optimum efficient design for the solar tracking system in published papers over the past three decades. This paper presents an in-depth overview of the assessment parameters and characteristics of various sensor devices employed to provide precise feedback control mechanism used in dynamic solar tracking systems. We found that the webcam sensor device has superior capability compared to other solar sensors devices. In conclusion, we propose a future research direction for a better efficiency and effective dynamic solar tracking system. Keywords: Solar tracking; Solar sensors; Solar panels; Overall output generated energy; Webcam; Photoresistors; Photodiodes; Feedback Control mechanism

Metal halide lamp (MH) is widely used in stadium lighting because of its significant advantages. But this high-intensity gas discharge lamp circuit contains the arcand such negative resistance characteristics lead to harmonic current. In addition, electronic ballasts of MH with rectifier circuit and inverter also produced a large number of electrical harmonics, becoming the main harmonic sources. In this paper, piecewise linearization method is used to establish the electrical model of 2500W metal halide lamp and a three-level model of electronic ballasts with the PSCAD/EMTDC. This paper analyzed the grid side harmonic current when the model is running. Comparing the simulation results to the measured data of Shenzhen Universiade venues lighting circuit, we can verify the accuracy of the model.

Modern radar systems should transmit different waveforms according to different environment. Waveform design is an important problem in radar system design. In this paper, we compare two waveform design methods based on MI and SINR with the signal model of a Gaussian target ensemble in ground clutter. The simulation results show that for the different tasks of radar, the energy allocation modes are different. Finally, the whole paper is summarized.

It is a new method of pipeline detection that pipe detector based on laser. This paper introduces the laser inner diameter detector related principle, detail the state of development and the latest development of pipe detector based on laser designed and made by domestic and international companies, and contrastive analysis the function of pipe detector. The paper proposed development prospect and the main technical difficulties of the pipeline laser detector. The development direction of pipeline laser detector is high efficiency, high precision and high speed. However, the key technical difficulties of in pipe detector based on laser, such as centering problem, reliability and accuracy problem, data analysis and processing problems. Keywords:Pipeline; Laser; Detector; Inner diameter

This paper presents the design of low noise CMOS pre-amplifiers based on photoelectric detection systems, which can directly affect the detecting precision of the whole systems. The design of pre-amplifier circuit from photoelectric detector was introduced. The photoelectric conversion circuit, amplifier circuit bandwidth, amplifier circuit noise, amplifier circuit stabilization and other questions were mainly discussed, and an amplifier circuit capable of effectively decreasing the noise, the temperature drift and a large dynamic range was designed. This paper analyzes the sources of photoelectric detection circuit internal noise, and gives the formulas of internal noise, designs a variable equivalent load photoelectric conversion circuit, and is verified by experiments. Then the result is used to reduce the noise of CMOS based operational amplifiers and finally implement the design work of pre-amp using 0.5μm CMOS Technology.

Gate control TWT damaged easily in high voltage and high frequency work environment of radar transmitter. The development stages of the monitoring system core technology for radar transmitter experienced relay, single-chip computer, embedded industrial computer and programmable logic controller (PLC). Embedded industrial computer and PLC monitoring system is commonly used now, and this paper gives a relatively complete system of the above. Using the power monitoring method for key parameters of gate control TWT for indirect acquisition and monitoring is proposed in this paper. Provide reference for designing a reliable, stable and efficient monitoring system of radar transmitter.

Retracted paper: Intra-body communication is proposed by Zimmerman in 1995 and the galvanic coupling has been observed to be the best method for data transmission. With the increasing transmission requirements and the development of optical fiber communication, a high speed system is possible to be designed based on the Electro optic methods. In this paper, the characteristics of the intra-body communication system are introduced. Principles and structures of optic modulation for intra-body communication are reviewed. Internal and external modulation methods are introduced and discussed. A system of the electro optic modulation is recommended and discussed.

When multiple targets run through radar at the same time, the current traffic speed radars have more speed error. This paper presents an improved measuring method, provides a solution to improve time-frequency resolution. We can improve the speed resolution when adopting the algorithm proposed in the paper.

RTD (resonant tunneling diode) is a nonlinear device in nm scale level and operates at ps time level which is promising to be used into integrated circuits in the coming years. J.N.Schulmans physical model has beenproven to be suitable to emulate the device accurately. In this paper, a novelRTD based on new material structure is proposed which could reach a relative high PVCR (peak-valley-current-ratio). Then NFP (Nonlinear Fitting based on Physical model) method which is suitable to calculate the parameters for Schulmans physical model more quickly is proposed. At the end of paper the SPICE model of the proposed RTD is proven that it could emulate the RTD device, and shows its application ability in high frequency oscillation circuit.

This paper introduces a technology that 16 LED chips are integrated on a substrate to form a new type of high-voltage LEDs chipset. Monte Carlo method and Finite Element Method simulation are used to optimize the structure for making the best in the luminous flux, luminous efficiency and heat dissipation. Firstly, By the comparison of three kinds of high-voltage LEDs, the vertical structure, inverted trapezoidal structure and trapezoidal structure, the results show that the luminous efficiency of the entire high-voltage LEDs chipset used trapezoidal structure is the highest, the empirical data is 41.522%, which is 2.12 times than the vertical structure; this paper introduces the heat transfer performance of three kinds of high-voltage LEDs, the empirical data are 88.374°C, 82.652°C and 93.725°C. We can see that the vertical structure is the best. This paper also optimizes the high-voltage LEDs chipset, under the circumstances of the constant chip area, we change the area of the single chips, prompting the spacing between the single chips change. We get the best single chip area and single chip change, under this circumstance, we can get the best luminous efficiency and luminous flux.

After the completion of the CMOS(Complementary Metal-Oxide-Semiconductor Transistor) camera module assembly,in order to test the image quality of module. In this paper, based on the ISO12233 standard chart proposing a CMOS camera module modulation transfer function MTF (modulation transfer function) of test method, MTF average value calculated for each module with high contrast and grayscale method, and validation processing to detect unqualified imaging module. The results show that MTF detection method used in this paper can quickly and accurately detect the quality camera module, and stable and reliable, playing an important role to found the quality problems and improve the efficiency of production.

In this paper, the main factors influencing the reliability of submarine optical fiber cables (SOFC) are analyzed, and the significance of the research on real-time monitoring technology of SOFC is illuminated. Also, the principle of distributed double Mach-Zehnder (M-Z) interference vibration sensing system is discussed. Then, the feasibility of the system applied in pre-warning and fault location of SOFC is verified. In view of the main problems of the optical fiber vibration sensing system, two optimization schemes are presented in this paper to improve the performance of the system.

A novel apparatus is introduced in this paper used to measure high voltage electric energy based on three-phase four-wire virtual-ground theory. The virtual-ground design, Faraday shielding technique and Warner DC (Direct Current) self-supply method are integrated in this apparatus based on new I/V, V/V techniques to realize high accuracy, reliability and wide-linear range measuring. The effectiveness of the apparatus has been proved by in-house calibration and on-site test . The test result shows that it can be used in high voltage grid on-site calibration . Its measurement uncertainty can be limited to 0.1% under the condition of PF=1.0~0.8, and can reach 0.15% as PF=0.5. In summary, the apparatus discussed in this paper can be applied as high voltage electric energy measurement instrument to meet the requirement of online metrological verification and calibration. Furthermore, it is very useful for building the system of Advanced Metering Infrastructure (AMI) in smart grid.

After studying the relationship between the moisture content of crops and their relative permittivity, the principle of capacitive sensor and the research results of measuring micro-capacitance, this paper summarizes the theoretical basis of dielectric properties of grain, the dielectric properties of wheat, corn and rice, the relationship between the dielectric properties of these crops and their water content. With these theory analyses, the paper gives a full look on the grain moisture detection system by the means of dielectric properties, which consists of six parts, a cylindrical capacitor, signal conditioning circuits, single-chip control module with an A/D converter, temperature detection module, keyboard module and display module. The system is simple, and can adapt to extreme environment and accomplish the rapid detection in manufacturing. A description is given of the principle, its hardware circuit and software programming flow chart.

Under high voltage and ferromagnetic condition, the optical fiber, as the new communication carrier, is widely used in power signal transmission. However, the interference rejection performance of optical-fiber transceiver, an important part of photoelectric conversion, has always been of great concerns. Whether the optical fiber transceiver works properly or not, will directly affect the quality of the whole communication network. This paper focuses on the time-domain and frequency-domain features of power ports and control ports under the strong transient electromagnetic disturbance. At the same time, this paper makes use of magnetic toroid to suppress electromagnetic interference (EMI). The results provide a reference for future anti-jamming design of optical-fiber transceivers.