bluuebunny/crossref_metadata_2025 huggingface dataset:
Shaking Table Test on Seismic Performance of Combined High Voltage Circuit Breaker
Authors: Li Hongbo
Published: March 2020

This paper focused on the experimental characteristics of seismic performance on a typical combined high voltage (HV) circuit breaker. Through the shaking table test of the scale model of a “T”-type circuit breaker, the results indicated that the test model could better reflect the main force characteristics of the prototype structures. Meanwhile, the dynamic characteristics of the model structure were reflected by white noise sweep frequency, and the seismic response of the model structure under the excitation of different seismic waves with different intensities were studied. It is concluded that the vulnerable parts of the model structure appeared at the root of the structural insulation porcelain column, the top and the bottom of the structure. Generally, the magnification coefficient of acceleration is about 1.1-2.7.
Optimum Design Operation Principles and Simulation Results of DC Breakers in High Voltage DC System
Authors: Meng Dedong
Published: March 2020

The feasibility DC power applied in distribution system is discussed. The efficiency and topologies of applying DC distribution for different purposes are investigated as well. For applying DC distribution, there are two key components, AC/DC converters and DC breakers. This thesis investigates the specification of converters suitable for applying in DC distribution system. In those converters, power losses are calculated as an index to compare their overall efficiency. Voltage control on the DC side and power factor correction on the AC side are also the primary requirements. Due to the absence of natural zero crossing current, the design of DC breakers is different from AC ones, therefore, in this thesis, the design rules of different DC breakers are investigated and their performance are also compared as a reference when selecting suitable DC breakers.
Research on the relevance of the cost of power cable and macroeconomic indicators based on comprehensive cost index calculation
Authors: Wang Hanze , Ma Xin , Huang Kai , Liu Jinpeng
Published: March 2020

With the rapid development of productivity, the demand for power supply is increasing dramatically. As a safe and reliable way of power transmission, the investment scale of power cable engineering is increasing. This paper innovatively puts forward a calculation method of cable line engineering’s comprehensive cost index, which accurately reflects the variations in cable line engineering’s comprehensive costs with different voltage levels and various construction technologies within a certain period of time. Furthermore, it explores cable line engineering’s comprehensive cost index and the correlation between macroeconomic indicators. The correlation coefficients between research objects are calculated. The research shows that there is a strong correlation between the law of power cable engineering cost hole and macroeconomic index, and the fluctuation of raw material price index also has a profound impact on the cost.
Research on Three-phase Variable Frequency Power Supply Based on DSP and SVPWM Technology
Authors: Fan Shiyong , Wang Shudong
Published: March 2020

Starting from the defects of analog power supply. Based on the analysis of space vector pulse width modulation algorithm, a three-phase variable frequency variable amplitude inverter power supply based on SVPWM technology is studied. On this basis, the PI control algorithm for closed-loop control of inverter power supply is also proposed. In order to improve the system response speed, the DSP with powerful digital signal processing capability was designed as the hardware platform, and various related verification experiments were completed. The results show that the system realizes a voltage-regulated output with a step of 1 V and a range of 40 V and an FM output with a step of 2Hz and a range of 50Hz to 1kHz. The system has small load regulation rate, excellent performance and good application prospects.
Study on Regional Comprehensive Energy Efficiency Evaluation Method
Authors: Cheng Liang , Wang Linyu , Sun Yaling , Wang Yongli , Zhang Danyang , Wang Jingyan
Published: March 2020

Integrated energy service is a new type of energy service to meet the diversified energy production and consumption of end customers, covering energy planning and design, engineering investment construction, multi-energy operation services and investment and financing services. This paper considers the energy input-output ratio, energy thermal efficiency and pollution gas emissions of the park, and comprehensively constructs an indicator system for the comprehensive energy park, which can provide guidance for the evaluation of comprehensive energy parks in the future.
DC Distribution Power Grid Voltage Level Sequence for Urban Power System in Integrated Energy System
Authors: Sang Zi-Xia , Zheng Xu , Yan Jiong , Wang Si-Cong , Du Zhi , Huang Jia-Qi , Chen Zhu , Huang Da-Wei
Published: March 2020

The development of HVDC technology makes it possible to build a multistage HVDC distribution power system. Firstly, the basic principles and main constraints of voltage level sequence for DC distribution are analyzed in detail. Based on the analysis of the DC distribution capacity of each voltage level, a series of voltage levels of DC distribution network with high voltage, medium voltage, low voltage and ultra-low voltage are proposed, taking the load demand as the basic foundation, considering the manufacturing level of relevant equipment and the need of power grid structure optimization. Finally, the specific voltage level sequence of DC distribution network is proposed.
Analysis about Power Supply Capability, Economy and Reliability on Voltage Level Sequence of Urban DC Distribution Power System in Integrated Energy System
Authors: Sang Zi-Xia , Zheng Xu , Yan Jiong , Wang Si-Cong , Du Zhi , Huang Jia-Qi , Chen Zhu , Wang Qi-Xin
Published: March 2020

With the development of DC power transmission technology, it is possible to develop a multilevel urban DC distribution system in integrated energy system. With the basic principle and main constraints of designing for DC distribution voltage level sequence, a sequence of voltage levels of DC distribution power system in different voltage levels is proposed, and the power supply capability, economy evaluation and reliability on voltage level sequence of multilevel DC distribution is discussed in detail through a specific example.
The Interruptible Load Control Strategy of Distribution Network in Integrated Energy Service System
Authors: Sang Zi-Xia , Zheng Xu , Yan Jiong , Wang Si-Cong , Du Zhi , Huang Jia-Qi , Chen Zhu , Wang Qi-Xin
Published: March 2020

In the integrated energy service system, distribution network shall manage to settle its own power balance issue. The market competition that grid corporations open the sale services of electricity to the society and interruptible load is encouraged to participate in ancillary services becomes a development tendency. At this time, a corresponding control strategy was required to instruct interruptible loads scheduling. In this paper, a control strategy using discrete Fourier transform is proposed in combination with the requirements of the electricity market. Under the constraint of the new evaluation criteria, different types of resident interruptible loads were on-demand dispatched in different periods. The root mean square error (RMSE) of the feeder daily forecast could improves the power load control capability of distribution network as well as the quality of power supply.
The Redundancy Scheme Optimization of DC Distribution Transformer for Electric Vehicle Charging Facility
Authors: Yan Jiong , Sang Zi-Xia , Zheng Yun-Fei , Wang Si-Cong , Du Zhi , Huang Jia-Qi , Chen Zhu , Wang Qi-Xin
Published: March 2020

The DC distribution transformer for electric vehicle charging facility is the key equipment in future active distribution power system, whose reliability relates to robust and reliable operation of distribution power system. With redundancy modules, reliability of the DC distribution transformer is increased as well as the cost. The reliability with different control methods for general DC distribution transformer is analyzed and compared, and an objective function is presented for optimized design. Solutions for minimum value of the function under different circumstances are discussed, and the best scheme for balance between reliability and economy is obtained. Finally, an engineering application is analyzed. Suggested model and number of sub-modules is given, and validity and feasibility of the proposed method is verified.
Long-term mechanism and key issues of trans-provincial and trans-regional power transmission
Authors: Tang Chenghui , Zhang Fan
Published: March 2020

In recent years, the trans-provincial and trans-regional power transmission have been an important manner in the power industry development in China. However, some annual capacity factors of power transmission lines are at a low level. This could reduce the power resource allocation efficiency and increase the social electricity cost. In this paper, the long-term mechanism and key issues of trans-provincial and trans-regional power transmission are studied, which aim to eliminate unnecessary transmission restrictions of the transmission lines based on long-term multilateral agreements.
Broken Rotor Bar Fault Diagnosis of Squirrel Cage Asynchronous Motor Based on Vibration Spectrum and Current Spectrum
Authors: Zhang Shuai
Published: March 2020

In this paper, the vibration spectrum and current spectrum analysis technology are used to accurately diagnose the broken rotor bar fault of the slurry circulating pump motor. This paper elaborates on the mechanism of broken rotor bar fault, deduces the common motor pole pass frequency calculation formula, introduces the specific diagnosis process and disintegration of the broken slurry circulating pump motor’s rotor bar breakage fault. The cause of the fault is analyzed, and this type of the fault diagnosis method is also summarized.
Economic dispatch of WT-PV-ES with cogeneration in abnormal regulatory domain
Authors: Ge Weichun , Yu Fengjiao , Liu Qianwei , Wang Shunjiang , Su Anlong , Pan Chao
Published: March 2020

The combined operation of cogeneration, distributed generation and energy storage can effectively meet the electrical and heat load requirements in the northern region, but its economic dispatching problem needs to be solved urgently. An economic dispatch model of WT-PV-ES with heat and power in abnormal regulatory domain is built considering economic cost and environmental cost. Meanwhile, an improved black hole algorithm is proposed, which applied the global search mechanism to improve the search efficiency and ability of optimization. The IEEE30 power distribution system and 6 node heat system are used for simulation. It is verified that the correctness of the proposed model and method.
Comprehensive Evaluation Method and Case Study on the Promotion and Application Effectiveness of Shore Power Supply Systems
Authors: Mao Ning , Cheng Jinxiang , Li Yue , Zhi Xiahui , Xu Honglei
Published: March 2020

The use of shore power supply system for ships at ports is one of the key promotion technologies for ship emission control according China’s 13th Five-Year Plan.However, there currently lacks established evaluation methods both in Chinaand abroad for the assessment ofshore power effectiveness. This study focuses on the most prevalent issues faced by various local regions in their promotion and application of shore power, proposes a set of evaluation methods tailoredfor local governments in the evaluation of promotion and application from five perspectives: construction and utilization of shore power facilities, institutional mechanisms, incentive policies and regulatory framework as well as a comprehensive evaluation of shore power effectivenessin Shenzhen as a case study. Results demonstrate that theevaluation method can fully reflect the effectiveness of local governments in their promotion of shore power, identify existing issues and opportunities for improvement, and may provide a baseline for the next-phase promotion of regional shore power facilities.
Optimization of vector control torque ripple of permanent magnet synchronous motor based on internal model principle
Authors: Ma Xihe , Lv Yingjun , Lv Changzhi , Zhang Yatong
Published: March 2020

Due to the dead zone effect caused by the non-ideal device of inverter, the currents of the quadrature and straight axis in the synchronous rotation coordinate of permanent magnet synchronous motor (PMSM) contain a large number of harmonic components, resulting in violent torque harmonics. Based on the field weakening control in single current regulator of interior permanent magnet synchronous motor (IPMSM), this paper gives an analysis of the reason for speed fluctuation, and a novel current compensation control strategy based on internal model control is proposed. By this means, the influence of harmonic currents on electromagnetic torque can be reduced meanwhile the advantage of single current regulator in filed weakening control is fully exploited. The feasibility and effectiveness of the proposed scheme are evaluated by Simulation analyses and experimental results.
Study on prediction model of construction period of power transmission and transformation project based on support vector machine
Authors: Yan Qingmeng
Published: March 2020

With the improvement of people’s living standard, the demand for electric energy is increasingly strong. In order to meet the increasing load, the construction scale of power transmission and transformation project of power grid company is increasing, and the difficulty of progress control of power transmission and transformation project is increasing. In order to control the progress of power transmission and transformation projects, it is necessary to make an accurate and reasonable time prediction to make a realistic and feasible schedule. Firstly, this paper analyses the influencing factors of the construction period of power transmission and transformation projects, and determines the key decision factors. Based on the support vector machine method, a prediction model of the construction period of power transmission and transformation projects is established. The prediction accuracy reaches 95.50%, with high accuracy.
Development of a new special combination tool for substation secondary service
Authors: Zheng Liwei , Guo Jianling , Liu Mingjun , Tian Haoye , Li Honglei , Jiang Chuan
Published: March 2020

In order to ensure the safety of power production, enhance substation secondary professional capability, especially improve the efficiency of the secondary professional in stripping cables. For conventional wallpaper knives, wire strippers, etc. used in traditional work. We carried out an overall improvement and upgrade, and combined the improved tools into a special combination tool for substation secondary inspection. It has been proved by practice that after using the special combination tool for substation secondary service, the work safety factor can be effectively enhanced, and the working efficiency of the secondary professional stripping cable is greatly improved. The special combination tool for substation secondary inspection proposed in this paper is of great significance for standardizing secondary professional operation standards, ensuring work safety and improving work quality.
A portable cable head insulating rubber cap
Authors: Zheng Liwei , Li Honglei , Liu Mingjun , Guo Jianling , Tian Haoye , Sun Dianlong
Published: March 2020

The importance of safety, efficiency and economy in the production of power systems is increasing. However, in the daily work, the traditional insulating tape which is used to insulate the bare wires has the problems of low safety, poor efficiency and serious waste. To this end, a portable cable head insulating rubber cap is proposed. The advantages of the new insulating rubber cap are remarkable. It is easy to install and disassemble and can be reused. It effectively solves the problems of safety, efficiency and economy in the past working methods. It is of great significance to ensure safe production and improve the quality of work.
Development of special tools for maintenance and testing of substation primary and secondary equipment
Authors: Zheng Liwei , Wang Wei , Liu Mingjun , Li Long , Li Honglei , Tian Haoye
Published: March 2020

In order to improve the work efficiency of the first and second overhaul of the substation, and to ensure the personal safety of the staff, this paper proposes a retractable test line box for secondary maintenance and a V-type porcelain column break insulation protection frame for isolation control of primary equipment. The wire box can effectively shorten the time of test wiring and make the on-site debugging work more convenient. The insulation frame guarantees personal safety. The retractable test line box and the isolating switch V-type porcelain column broken insulation protection frame can be used to improve the efficiency of the first and second on-site inspection and debugging, and effectively protect the personal safety of the staff.
Measurement and Analysis of abnormal noise of 10kV switch Cabinet
Authors: Chen Wei , Wu Xiaowen , Hu Sheng , Cao Hao , Xie Yine , Lu Ling
Published: March 2020

When the load current flows through the main row of the switch cabinet, the induction current is generated on both sides of the cabinet, and the electric power of the interaction between the bus and the panel appears. Because of the thin switch cabinet panel and double-layer plate structure, when the load current is large, the double-layer panel vibrates violently and collides with each other under the action of electric power, and then resulting in abnormal noise. It may lead to hidden danger of equipment safety for long time. In this paper, acoustic imaging technology is used to accurately locate the sound source, and then the vibration acceleration amplitude is measured by the vibration sensors. Based on its spectrum characteristics analyse result, the causes of abnormal noise are discussed and solutions are put forward.
Design of noise Control Scheme for 500kV Substation
Authors: Hu Sheng , Chen Wei , Wu Xiaowen , Xie Yine , Tang Qi , Lu Ling
Published: March 2020

The noise of substation is generally generated by the main transformer, reactor, capacitor and other electrical equipment, in which the transformer is the main sound source equipment. Its spectrum characteristics are mainly low frequency noise, medium and high frequency noise as auxiliary. The noise band is wide, the wave grow is long, the attenuation is slow, and the penetration ability to the building structure is strong, which seriously affects the daily life of the residents. In this paper, the noise source of a 500kV substation with noise exceeding the standard is tested and analyzed first, then the noise reduction scheme design and sound field simulation calculation are carried out to verify the feasibility of the scheme.
Critical Section Channel Maintenance Evaluation Method for Double HVDC Feed-in Grid
Authors: Xie Yan , Liu Yi , Gao Kun , Xiong Haoqing , Rao Yufei , Huo Qidi , Chen Meng , Tang Xiaojun
Published: March 2020

In order to ensure stable operation of DC, the dual DC feed grid structure needs to ensure a certain grid strength, but it is necessary to study how to evaluate the impact of critical section maintenance on the AC system. Firstly, the strength evaluation index of the receiving power grid is analyzed. Secondly, an index that characterizes the effects of two DC couplings is proposed. Finally, a critical section channel maintenance evaluation method for double ultra-high voltage DC feed grid is proposed. The effectiveness of the proposed method is verified by the HN Power Grid simulation.
Research on ship electric propulsion
Authors: Jin Zhemin , Yang Yuxin
Published: March 2020

Ship electric propulsion is widely favored in the marine industry due to its good economics, maneuverability and low noise. The modeling and simulation research of the ship’s electric propulsion system is carried out, and the steady state and dynamic working process of the system are reproduced. The inherent laws of the system are revealed, which is of practical significance for guiding the design and use of the ship’s electric propulsion system. The ship’s electric propulsion system is a complex and variable nonlinear system. In addition, its propulsion motor has the characteristics of large capacity and large moment of inertia. It is very important to accurately model and simulate it. The main content of this paper is the systematic research and development prospects of marine electric propulsion systems.
Research on Economic Dispatch Optimization Model of Small Hydropower Group Considering Power Supply Cost
Authors: Liu Fei , Zhang Haining , Sun Yaling , Wang Yongli , Tian Xu
Published: March 2020

Due to the large number of scattered small hydropower, disordered grid connection, unplanned power generation, and old equipment overvoltage, etc. It has brought great challenges to the power supply security of Sichuan Power Grid. Aiming at the minimum system power supply cost, the economic dispatch optimization of small hydropower groups within the system is realized. The nonlinear mixed integer 0-1 programming is solved by adaptive simulated annealing genetic algorithm. The results show that the total cost of power generation after the optimized power generation plan. It is lower than the cost of all the power stations in the flood season, further indicating that the scheduling optimization can effectively reduce the system power supply cost, and guide the Ya’an small hydropower group. Economic dispatch is of great significance.
Vibration Signal Analysis of Rotating Machinery Based on Manifold Learning
Authors: Wang Hao , Zeng Yuyun , Xie Guangyao , Wang Xiaoshang , Liu Jingquan
Published: March 2020

Vibration signal contains the fault information of rotating machinery, so it can be selected to monitor the health status of rotating machinery and provide an early warning. But vibration data of rotating machinery usually has the characteristics of large amount of data and non-linearity, and traditional data processing methods are difficult to analyze effectively. Therefore, in this paper, based on the statistics and wavelet packet decomposition, the time-frequency domain characteristics of the signal are extracted. And then the feature set that can characterize the running state of the rotating device is selected according to the Pearson correlation coefficient. At last, the manifold learning method is used to calculate the feature set. The result shows that this method can effectively monitor the running state of the rotating machinery.
Study on the economic analysis model of new energy power generation under the form of grid parity
Authors: Tian Xu , Zhang Yvli , Che Yanying , Wang Yongli , Zhang Jun
Published: March 2020

This paper first analyzes the influencing factors of the economy of new energy power generation under the situation of grid parity, then studies the economic analysis method based on the internal rate of return, and establishes the calculation model of the economic analysis of new energy power generation. Finally, taking the economic calculation of wind power field and photovoltaic power station in 2020 as an example. This paper studies the IRR of new energy power generation projects in different regions under parity conditions. On this basis, the paper analyzes the key issues of new energy development scale, development layout, operation consumption, market competition and so on under the situation of grid parity, and studies and judges the development trend of new energy in China in the future.
A Simplified Predictive Control Method of Power Frequency Electric Field on Roof near 500 kV Transmission Lines
Authors: Huang Mingxiang , Wang Yifei , Bian Hongzhi , Yang Dongyang
Published: March 2020

In order toget a simplified predictive control method of power frequency electric field on roof near 500 kV transmission lines, a three-dimensional electric field simulation model including the lines, tower and house isestablished based on the finite element method. Based on the knowledge that obtained from existing studies, the spatial distance between the house and the transmission line is the main factor affecting the power frequency electric field intensity on the roof. Therefore, the spatial distance is determined as a variable, and the least squares method is used to fit the optimal electric field distribution function. A simplified prediction model of the power frequency electric field at fixed monitoring point on the roof near the transmission line is derived. The results show that the fitting function of the third-order polynomial can achieve better predicting effect. The specific mathematical expression of the prediction model is provided.A deductive process of the application of the proposed method is given. The proposed power frequency electric field predictive control method can provide reference for the planning, design and environmental impact assessment of transmission line projects.
Adaptive Neural Fuzzy Petri Net Algorithm for Motor Fault Diagnosis
Authors: Wang Changan , Li Jiming , Zhu Xiaolin , Xu Chuannuo , Cheng Xuezhen
Published: March 2020

This study aimed to improve the application of fuzzy Petri net to fault diagnosis of motor systems. An adaptive Neural Fuzzy Petri Network Algorithm based on the traditional Petri net theory, fuzzy theory, and neural network algorithm is proposed and applied to the diagnosis of motor faults. The transition confidence is replaced by a Gaussian function to solve the uncertainty of fault propagation. Combined with the BP neural network, fault diagnosis parameters are adaptively trained. Finally, the Neural Fuzzy Petri Net Algorithm is applied to the fault diagnosis of a three-phase asynchronous motor, considering its fault operation mechanism and fault characteristics. The results show that the algorithm can diagnose the fault of the three-phase asynchronous motor with satisfactory accuracy and adaptability.
A data driven health assessment model for high pressure output pumps in LNG terminals
Authors: Zeng Yuyun , Wang Xiaoshang , Xie Guangyao , Liu Jingquan
Published: March 2020

High pressure output pumps are critical equipment in the vaporization and output system of LNG terminals. Health management helps improve efficiency and reduce cost of the maintenance of high pressure output pumps, thus guaranteeing the efficient productivity of LNG terminals. In order to develop health management system for high pressure output pumps, a data driven health assessment model based on online condition monitoring data of the pumps is proposed. Time domain and frequency domain features are extracted from the monitored vibration signal by statistical analysis and wavelet packet decomposition respectively, and a health index is constructed based on T2 and SPE statistics given by PCA results of the extracted features. The proposed model is validated based on monitoring data of high pressure output pumps in Qingdao LNG terminal. Results show that the calculated health indices are good indicators of the health status of the pumps, and are able to detect potential fault in their early development stages.
Design of two-way self-moving linear ultrasonic motor
Authors: Bai Kai , Li Chaodong , Xi Cong
Published: March 2020

This paper designsa two-way self-moving linear ultrasonic motor. The ultrasonic motor is composed of a diamond-shaped metal elastic body, a piezoelectric ceramic piece and a parallel guide rail. There is a slight gap between the driving foot and the parallel guide rail on both sides of the metal elastic body, and the grounded aluminum tube is sandwiched between the diamond-shaped metal elastic body. By exciting the piezoelectric ceramic sheets on both sides of the elastic body, the first-order bending vibration mode is excited to realize the bidirectional movement of the motor. Based on the analysis of the working principle of the ultrasonic motor, the finite element harmonic response analysis of the ultrasonic motor was carried out. A prototype is made for mechanical properties experiments. Experiments show that under the excitation of 200Vpp, the forward and reverse frequency of the ultrasonic motor is 18.18KHz and 18.07KHz, and the forward and reverse no-load speed is 43.76mm/s and 43.14mm/s. The no-load speed is close to.
Static Frequency Test and Vibration Safety Analysis of Turbine Blades in a Power Plant
Authors: Chai Baotong , Wu Zhengfeng , Zhang DongXing
Published: March 2020

During the overhaul period of steam turbine in some plant, the blades’ vibrational security had been analyzed through the stationary frequency on the spot from the blades by using spectrum analyzer of Nanjing trued software engineering co., Ltd. The results of the test showed the turbine’s blades of next to last stages (stage groups) were safe when they were in operation with the working rotating speed.
Discussion on RB technology and the application in 330MW unit
Authors: Li Yuanyuan , Yan Qing , Han Yingkun , Gao Song , Yu Qingbin , Li Kelei , Liu Enren , Meng Xiangrong
Published: March 2020

The RB function can automatically reduce the unit to a specified value after the main auxiliary equipment of the power plant is tripped to reduce the number of unit outages, which is beneficial to the stability of the power system. Based on the experiments of RB test on different types of power units, this paper makes research of RB technical problem, analyzes the characteristics of RB rapid load reduction and RB plan and test results in detail.
Construction and Empirical Analysis of Intelligent Prediction Model for Electric Grid Project Cost
Authors: An Peng , Liu Jiaguo , Rong Peng , Qi Xiang , Wang Qing , Dai Yong , Yu Baijian , Yuan Fei , Gao Yunxing
Published: March 2020

China’s economic situation has entered a new normal development period, the growth rate of national economic development has fallen, and the state has comprehensively implemented various measures such as price reduction and fee reduction, which makes the operation of electric power enterprises face greater pressure. In this paper, Shandong power transmission and transformation project is taken as the research object, using big data analysis technology and current popular intelligent algorithm to build the intelligent prediction model of power grid project cost, to assist in investment decision-making, reduce the balance rate, strengthen the fine control of investment, improve the precise control level of investment, and enhance the competitiveness of enterprises.
Research on Risk Assessment Technology of Investment Plan Implementation of Electricity Grid Construction Projects Based on Automatically Generated Fixed Asset Investment
Authors: Zhou Ming , Lu Shengwei , Wu Qiang , Jin Sha , Yan Jiong , Sang Zixia , Fang Rengcun
Published: March 2020

In order to achieve accurate verification of the implementation of power grid infrastructure investment plan, support the dynamic monitoring and risk assessment of annual investment plan implementation. Based on the “three rates in one” Investment completion collection value of 110 kV and above grid infrastructure projects, this paper constructs a risk assessment model for the implementation of the investment plan of grid infrastructure projects. Evaluate the rationality of the current reported investment progress, predict the risk of the implementation of the investment plan and quantify the risk amount of the implementation of the plan, timely discover the risk of the implementation of the investment plan, promote the timely resolution of problems, and improve the investment lean management level of power grid enterprises.
An energy storage capacity optimization method based on partition
Authors: Li Yan , Zhu Haifeng , Tian Fangyuan , Deng Kai , Li Wen , Tang Xiaobo
Published: March 2020

With the vision of large-scale deployment of grid-connected distributed energy storage system (ESS) in the distribution network, it is necessary to study the capacity optimization of ESS for striking a balance among investment, renewable energy (RE) consumption, power supply security and price arbitrage. In this paper, an ESS partition model based on the improved flame propagation model is proposed. The results of ESS partition are obtained by constructing indexes such as the flammability of nodes, the wind direction of flame propagation, and the speed of flame propagation. Then, an optimization method for ESS capacity in partition is established, which is to maximize the annual net profit and the integer programming method is used to solve the model. Finally, the effectiveness and feasibility of the method are verified by conducting case studies on the IEEE 33 bus distribution network system. The case study results show that the rational configuration of ESS capacity can improve the economy of planning, and the proposed method can improve the Photovoltaic (PV) local consumption ability and power supply reliability of distribution network.
Typical Cohesion Modes of Foreign Long-Term Power Market with Spot Market and Implications for China
Authors: Yang Su , Chen Kening , Ma Li , Qu Yanyuan , Wu Zechen , Zhang Xiaoxuan
Published: March 2020

Since the 9th document issued by the Government, China’s power market construction process speeds up. Long-term trading and spot trading are both important components of a complete market system. This paper summarizes the cohesion methods and coordinated operation mechanisms of long-term trading and spot trading in typical foreign power markets. This paper also analyzed the advantages, disadvantages and applicability of the cohesion methods of different types of long-term transactions and spot transactions, and propose suggestions for China. It can provide technical support and decision-making reference for relevant government departments to formulate long-term and spot trading rules, and promote the scientific and orderly development of power market.
Design of an online monitoring system forthree-phasebelted HTS cables
Authors: Wei Bengang , Zhou Siyu , Sun Zhonghua , Wang Yifei
Published: March 2020

Three-phase belted High Temperature Superconductor (HTS) cables have compact dimensions and small inter-phase magnetic interference, and have been applied in the Demonstration Project of Domestic km-Level HTS Cable System of State Grid Corporation of China. The three cores of three-phasebelted HTS cablesare bundled together in the same low-temperature bellows, so a single-phase fault may cause the quench of other two phases, and even lead to an overall failure of the three-phase belted cable. Based on the cable body characteristics, cable termination characteristics and cooling system characteristics of the three-phase belted HTS cables, the related online monitoring parameters and monitoring methods are proposed. The design of an online monitoring system for the three-phase belted HTS cables is introduced.
The Impact of Sampling Period Change on Dynamic Phasor Traceability Algorithm Using Least Squares
Authors: Lu Da , Yang Yubo , Zhao Sha
Published: March 2020

In recent years, the electrical signal in Power System becomes more and more complex because of large-scale applications of power electronic equipment. To accurately trace the dynamic phasor, the algorithm based on least squares is used. It is important to develop the dynamic phasor traceability algorithm with high accuracy, good real-time performance and satisfied dynamic property. In this study, the applicability of least squares in dynamic phasor traceability is studied. The relationship between the sampling period and the fundamental period is deduced based on the formula. The accuracy is verified when the sampling period is three quarters of fundamental period. The simulation results show that when the sampling period is three quarters of fundamental period, the frequency response amplitude of this algorithm is flat near the fundamental frequency. Thus, the dynamic phasor can be accurately traced.
Primary frequency modulation characteristics of photovoltaic power station suitable for grid connection certification
Authors: Yao Changqing , Yan Qing , Liu Zhaodong , Zhou Changlai , Li Yuanyuan , Liu Enren , Zhang Chao
Published: March 2020

Photovoltaic power station can participate in the primary frequency modulation of the power system for grid connection certification. The primary frequency modulation capability of photovoltaic power station is analyzed when the light intensity changes. According to theoretical and simulation analysis, by changing the control mode, the photovoltaic power station operated by load reduction can quickly respond to the drop and increase of frequency and reduce the change of frequency after disturbance. Overall results show that the photovoltaic power station with primary frequency control can reduce the frequency of system changes, implement the support for the frequency of the system, and make corresponding adjustment to improve the safety of power grid.
The architecture and key technology of fault inversion systemfor Hybrid UHV AC/DC power system
Authors: Jia Yupei , Wang Bing , Xie Mei , Chang Zhiqin , Jin Yiding
Published: March 2020

The architecture and key technology of fault inversion system for Hybrid UHV AC/DC power system are introduced in this paper. The complete and accurate fault inversion model of power grid is formed by integrating the off-line model of Power System Data Base(PSDB) with the real-time online model of Smart Grid Dispatching and Control System(D5000). This model not only solves the problem that the real-time online model lacks transient parameter, but also overcomes the difficulty that the off-line model cannot reflect the real-time operation condition of the power grid, Therefore, this model meets the requirements of timeliness and accuracy of fault inversion calculation. Based on this model, the simulation calculation and analysis of power grid are carried out, and the changes of electricity volume in the process of power grid fault are simulated accurately. The system has been installed successfully and put into use in the simulation centre of the State Grid. The fault inversion analysis is carried out for State Grid Dispatch Centre and East China power grid. Besides, the scientific validity of the proposed scheme is verified.
Research on On-line Monitoring and Regulation Technology of Pressure of High Voltage Transformer
Authors: Fan Houyang , Zhu Yuancheng , Zheng Wei , Qin Xiaowei , Wu Di , Zhong Dantian
Published: March 2020

In order to analyze the operating status of voltage and current transformers at high voltage levels, the methods of detecting transformer insulation level and infrared temperature are usually used, but such methods usually use manual measurement by portable instruments, and the internal defects of the transformer are difficult to find in time. This article proposes a suitable on-line monitoring method and regulation technology for the insulation oil pressure of high voltage transformers. The defects of the transformer can be judged by the change of the internal oil pressure, which can effectively find faults such as internal short-circuit, degradation, and partial discharge of the transformer. A mechanism is designed to adjust and release the pressure of expanders. The high voltage transformer pressure line monitoring device has developed based on the Internet of Things communication and solar power supply mode, which can monitor the internal operating status of the transformer in real time. When the internal pressure of the transformer suddenly increases, the designed pressure release structure of the expander will automatically rupture, release the internal pressure of the transformer, ensure the safety of the transformer body, and reduce the impact of the accident.
Design of Phase Control System for Parametric Array Loudspeakers Based on FPGA
Authors: Cheng Xiguang , Zhao Hongliang , Zhang Xu
Published: March 2020

In order to achieve accurate control of the audible sound of the acoustic parametric array in the air, fine phase control of the ultrasonic signal as a carrier is required. By establishing the parametric matrix mathematical model and the directivity function formula, the effects of delay accuracy on the ultrasonic carrier and the audible sound deflection angle are simulated and analyzed. The control of 16-channel phase-controlled parametric array excitation signal is realized by using the fast parallel processing speed of FPGA. The signal processing circuit is designed to D/A conversion and amplification of the parametric array excitation signal to drive the piezoelectric transducer array efficiently. The experimental results show that the system can achieve fine control of the parameter array carrier transmission delay. The control accuracy of the parametric array carrier for the 40KHz carrier is 1 ns, and the error delay is less than 1 ns.
Research on Power Grid Enterprises’ Investment Strategies on Incremental Power Distribution Projects in China
Authors: Wu Zechen , Yang Su , Xue Song , Hu Yuan
Published: March 2020

As the highlight of China’s new round of power reform, incremental power distribution reform has attract wide public attention. In order to adapt to the situation of reform, power grid enterprises need to develop investment strategies on the pilot projects, and determine the criteria for controlling, participating in or abandoning shares. This paper analyzes influencing factors for power grid enterprises’ investment decision, and build a investment-assisted decision-making model for incremental distribution reform. The investment-assisted decision-making model covers 5 dimensions of economic efficiency, project importance, development potential, government attitude, and image influence, with a total of 12 evaluation indexes. The authors also take four projects as examples for quantitative evaluation, proving the feasibility of decision-making model.
A Momentum-Based Method for the Mass Concentration Measurement of Pneumatically Conveyed Solid: Computational Verification
Authors: Liu Guanqing
Published: March 2020

A momentum-based method is proposed to measure the mass concentration of solids in pneumatic pipelines. The mechanism relies on the fact that particles flowing with the fluid will exert drag force and thus induce pressure increase on the fluid phase when they decelerate as approaching a static object or space in the flow domain. The pressure increase is expected to increase with the mass concentration of particles and the fluid velocity, and is also affected by the particles size and density. A conversion factor that indicates the extent to which particle momentum is converted to the fluid static pressure increase was defined. Computational verification of the mechanism was carried out with pulverized coal flow around a one-end closed tube with its opening facing towards the incoming flow. The pressure increase was quantitatively comparable to the fluid dynamic pressure when the solid-to-fluid mass ratio was of the same order of magnitude. The conversion factor was found insensitive to particle size over a wide range, which is advantageous since particle size distribution are usually not known in advance. Compared to most existing techniques, current mechanism is more robust and economic in industry field measurements.
Response characteristics of transient electromagnetic of fault structures in shallow stratum of underground space and its exploration
Authors: Zhang Pingsong , Ou Yuanchao , Hu Xiongwu , Li Shenglin
Published: March 2020

The key to detecting underground faults in shallow stratum of the city with transient electromagnetic method is the determination of the fault location and the characteristics of accurate underground parameters. In order to establish a field data acquisition device and method parameters suitable for the exploration of the fault structure in the shallow layer of the city, the corresponding numerical model is established based on the Shungeng mountain fault structure with shallow depth. The finite difference method is used to simulate and calculate the response characteristics of the transient electromagnetic field in the fault structure zone, which provides the basis for the field application of the method and technique. Then, based on the surface geological conditions of Dongshan section of the Shungeng mountain fault, by using the short-circuit transient electromagnetic method, field data acquisition observing system and relevant parameters suitable for transient electromagnetic prospecting of urban shallow fault structures were established through experiments on site technical conditions, and the geoelectric section. The structure and characteristics of shallow buried faults are judged and explained. The results show that the response characteristics of transient electromagnetic in the fault fracture zone are significant, and the location and structure of transient electromagnetic field can be easily distinguished. It can provide references for similar geological conditions.
Numerical simulation of consolidation settlement of the embankment of the Nansi Lake
Authors: Wang Zhenyu , Yang Lingqiang , Li Xiudi
Published: March 2020

The consolidation settlement of the lake embankment engineering under long-term load is very large. It makes the structure can’t work normally and even leads to severe damage. Therefore, it is very important to analyze the settlement of soft soil foundation for the stability and safety of the lake embankment. The mechanical parameters of soil in this area, based on the geological investigation report of the lake embankment, are used to analyze the engineering characteristics of lacustrine soil. The embankment of the Nansi Lake is selected as an object to analyze the consolidation deformation characteristics of the lake embankment. The consolidation settlement of the lake embankment is simulated by the finite element analysis software. The simulation data and analysis results are very important for studying local geological characteristics and hydraulic construction.
Dynamic response analysis of machine bridge of spillway gate
Authors: Wang Zhenyu , Yang Lingqiang , Sun Naidong
Published: March 2020

Under the action of earthquake, the seismic property of the machine bridge directly affects the normal use of spillway gate. At the same time, the type of infilled wall affects the seismic capacity of the machine bridge. To decrease the damage possibility of the machine bridge under earthquake, three finite element models are established by finite element software, and the dynamic time history analysis of the machine bridge is carried out. The stress and displacement of different models are obtained through the dynamic time history analysis. The best type of infilled wall is judged by comparing the seismic responses of three models. Based on the analysis results, the mechanical characteristics of the machine bridge under earthquake action are analyzed and the weak position of the structure is found. Therefore, some measures can be taken to further improve the seismic performance of the machine bridge. The calculation results have important significance for practical engineering.