01 March 2018, Volume 39 Issue 3

    

• Select all
  |

• Select
   Review of Multi-Energy Flow Calculation Model and Method in Integrated Energy System

   

  LI Jinghua, HUANG Yujin, ZHANG Peng

  Electric Power Construction. 2018, 39(3): 1. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.001

  Abstract ( ) Download PDF ( )   Knowledge map   Save

   ABSTRACT：   Integrated energy system is of great importance to improve energy efficiency and achieve sustainable development of energy.Multi-energy flow calculation is an important basic work for the planning, operation and control of integrated energy system.In order to make the related field workers carry out the research work of integrated energy system better, this paper reviews multi-energy flow calculation of integrated energy system.From two aspects of model and method, current research has been sorted out.First of all, the problem of multi-energy flow calculation is introduced.Then, the classification and generalization of multi-energy flow calculation models in electricity-gas-heat combined system are carried out.On this basis, the methods for solving the models are summarized.At last, some problems existing in multi-energy flow calculation of integrated energy system are put forward and some suggestions are given.

   
• Select
   Recent Progress and Trend Analysis of Standardization of Smart Grid User Domain

  LI Bin1, ZHANG Jie1, TIAN Shiming2, DONG Mingyu2, QI Bing1, SUN Yi1, ZHU Weiyi3

  Electric Power Construction. 2018, 39(3): 12. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.002

  Abstract ( ) Download PDF ( )   Knowledge map   Save

   ABSTRACT：   The smart grid is the development trend of the future power grid. Since the user domain is an important part of the smart grid, in order to realize the interoperability between grid and users, it needs to pay attention to the standardization process of the smart grid user domain, to meet the interoperability requirements between the power grid side, the user side, and the internal components of the system. Based on the important core standard series of the smart grid user domain, this paper analyzes the standardization status of the smart grid user domain. In combination with the concept model of the smart grid user domain, the differences of smart grid architecture model （SGAM） are compared and analyzed. Taking the microgrid as an example, this paper illustrates the standard difference analysis method through the SGAM model mapping method. By analyzing the standardization problem of smart grid user interface specification, such as data models, communication protocols and demand side resources management, it provides reference for smart grid user domain standardization, and supports the interoperability between supply and demand sides.

   
• Select
   Overvoltage and Synchronization Stability Analysis of Half-Wavelength Order and Full-Wavelength Order Transmission Systems

  XU Zheng, YANG Jian, SHENG Nengjin,LU Shaoqi

  Electric Power Construction. 2018, 39(3): 23. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.003

  Abstract ( ) Download PDF ( )   Knowledge map   Save

   ABSTRACT： A general circuit model for analyzing the steady and transient characteristics of half-wavelength order and full-wavelength order transmission systems is established, and the lossless and lossy line mathematical models of long-distance transmission systems are derived. The characteristics of the state variables at the sending and receiving ends as well as the distribution of the voltage along the transmission line when the transmission distance varies in the full wavelength range are analyzed by combining the theoretical analysis and numerical calculation. The synchronization stability of long-distance transmission systems is analyzed by using small signal analysis method, and the transmission distance range which can keep synchronization stability is obtained. The feasible transmission distance of the half-wavelength order and the full-wavelength order transmission system is determined according to the constraints of synchronization stability and frequency deviation. The transient power frequency overvoltage and the transient synchronization stability of long-distance transmission systems are studied by analytical method. The calculation formula for the location of the most serious fault point and the calculation formula for the maximum overvoltage are derived；and the transient synchronization stability of the system is analyzed based on the equal area method.

   
• Select
   Family Energy Management System Based on Edge Computing: Architecture, Key Technology and Implementation

  QI Bing 1, XIA Yan 1, LI Bin 1, SHI Kun 2, XUE Mingfeng 3

  Electric Power Construction. 2018, 39(3): 33. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.004

  Abstract ( ) Download PDF ( )   Knowledge map   Save

   ABSTRACT：   The integration of  information technology（IT） and operation technology（OT） promotes the intelligence of many terminal devices and creates powerful conditions for smart homes. However, with the increase of distributed terminal equipment and the diversification of business, the influence of network delay and congestion caused by magnanimous data is becoming more and more serious. Cloud computing technology cannot meet the needs of energy management. At the same time, edge computing technology proposes the idea of moving the amount of computation to the edge of the network, which can not only improve the real-time collaboration at the edge, but also promote the growth and optimization of the cloud model. This paper proposes a family energy system framework based on edge computing, designs the four tier architecture of data fusion and operation cooperation between heterogeneous platforms, and presents several detailed design scheme of common subsystems, which provides new ideas for the application of edge computing technology in smart energy applications.

   
• Select
   Process Level Fault Diagnosis in IEC 61850 Based Smart Substations

  ZHANG Yong1，LI Dan1，WEN Fushuan2，ZHANG Yan3，DONG Yi1，ZHENG Jianzi1

  Electric Power Construction. 2018, 39(3): 42. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.005

  Abstract ( ) Download PDF ( )   Knowledge map   Save

   ABSTRACT：   The process level is the key part of an IEC 61850 based smart substation, and a fault occurred in the process level could have direct impacts on data acquisition and delivery as well as the reliability and prompt operation of the protective relays and circuit breakers concerned. Hence, it is very important to quickly diagnose so as to promptly clear the happened fault in the process level, and this is the key problem to be addressed in this paper. The importance of the process level in the architecture of a smart substation is first clarified. Then, taking intelligent terminals, merging units and fiber optic links as the subjects of research, the possible reasons and risks associated with a fault in the process level are systematically analyzed, and a fault diagnosis method is presented. Finally, an actual fault is served for demonstrating the feasibility and efficiency of the proposed approach.

   
• Select
   Critical Line Identification in Power Systems By Combined Use of Objective Weighting and Inter-Degree Measure Methods

  ZHU Ling1，LIN Guanqiang1，YE Xiaojun1，HAN Chang2，LIN Zhenzhi2，WEN Fushuan2

  Electric Power Construction. 2018, 39(3): 49. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.006

  Abstract ( ) Download PDF ( )   Knowledge map   Save

   ABSTRACT： Identifying and then preferentially reinforcing critical lines in a given power system are very important for preventing the power system from a blackout or large-area outages and improving its secure and reliable operation. Under this background, this paper proposes 5 indexes for evaluating critical lines of complex regional power networks, i.e. the changes of the agglomeration degree, the changes of spinning tree, the connection importance of lines, the changes of transmission efficiency and the weighted flow betweenness of lines, with the topological structure and operation state of the system considered. The evaluation indexes can comprehensively take the impacts of various aspects on identification results of critical lines into consideration, which could overcome the limitation of a single evaluation index. Then, the CRITIC （criteria importance through intercriteria correlation） method is adopted to determine the evaluation weights of indexes, and the entropy weight and Kendall coefficient are employed to respectively measure the contrast intensity in and the conflicts among indexes. The inter-degree measure method is used to evaluate transmission lines synthetically and identify critical lines. Finally, a regional power system in Guangdong is utilized to demonstrate the effectiveness of the proposed method.

   
• Select
   Optimal Timing of Controlled Islanding Employing Wide Area Measurements and Combination Predictions

  LONG Fei1，CHENG Min2，YANG Wentao2，WEN Fushuan2，LI Li1，WU Guobing1，YANG Yinguo1

  Electric Power Construction. 2018, 39(3): 57. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.007

  Abstract ( ) Download PDF ( )   Knowledge map   Save

   ABSTRACT：   Controlled islanding represents an emergency control approach through dividing a large power system into several small ones by employing real-time information of the power system concerned. Implementation of controlled islanding at the appropriate time can prevent the power system from cascading failures, and thus large-area power outages can be avoided. Given the above background, a method to determine the optimal timing of controlled islanding is presented by utilizing data from the wide area measurement system （WAMS） concerned and combination prediction. Specifically, WAMS is employed to attain power angles and operating frequencies of generators in real time, and a combined linear prediction algorithm is used to forecast disturbed trajectories of generators, and hence the power system can be islanded before that operating frequencies of generators go beyond their limits. In this way, the emergency shutdown of generators can be avoided and the operation stability of each island after controlled islanding maintained. Moreover, a combined linear prediction algorithm is presented based on the well established auto-regressive moving-average （ARMA） algorithm and Kalman filter algorithm so as to achieve better prediction performance. Finally, the proposed method is demonstrated by the IEEE 39-bus test system.

   
• Select
   Distribution Network Reconfiguration Considering Voltage Difference of Multiple Substations

  XING HaiJun1, SUN Xin1, HONG Shaoyun2

  Electric Power Construction. 2018, 39(3): 65. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.008

  Abstract ( ) Download PDF ( )   Knowledge map   Save

   XING HaiJun1, SUN Xin1, HONG Shaoyun2

   
• Select
   Finite Time Robust Control of STATCOM Systems Based on Higher Order Sliding Mode 

  YANG Jie1,CAO Junwei1, FANG Taixun2,WU Koulin2, CHANG Xiqiang3

  Electric Power Construction. 2018, 39(3): 71. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.009

  Abstract ( ) Download PDF ( )   Knowledge map   Save

   ABSTRACT：  To improve the dynamic performance and robustness of the static synchronous compensator （STATCOM） control system, this paper proposes a STATCOM finite time robust control method based on higher order sliding mode control. Firstly, the strong coupling, nonlinear STATCOM system was linear decoupled by inverse system method. According to the system state after decoupling, twisting algorithm and super-twisting algorithm were adopted in reactive power compensation current and DC side capacitor voltage, respectively. These two control methods not only compensated reactive power current and DC side capacitor voltage rapidly in limited time but also had some robustness to the system uncertainties. Simulation results show the effectiveness of the proposed method.

   
• Select
   Hybrid Modulation Strategy of Modular Multilevel Converter

  WANG Weiru, XIN Yechun, CONG Jiaqi, YANG Yang, ZHANG Di, SONG Zhenzi

  Electric Power Construction. 2018, 39(3): 77. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.010

  Abstract ( ) Download PDF ( )   Knowledge map   Save

   ABSTRACT： According to the modular multilevel converter （MMC） in low voltage system, this paper proposes a hybrid modulation strategy for improving the output waveform quality of MMC in low level. Using the combination of the nearest level modulation and the pulse width modulation （PWM）, the step wave is formed by the nearest level approximation in each control cycle, and the PWM control is introduced on each step wave in order to form each arm modulation signal which is mixed by step signal and the PWM signal. The hybrid modulation strategy can improve the output waveform quality of the converter, reduce the harmonic content, and reduce the amount of modulation algorithm, which is beneficial to the realization of the controller. Simulation experiments are carried out on a 9 level converter connecting with 10 kV AC system. The simulation results show that the proposed modulation strategy makes the converter have better voltage and current output waveform, which verifies the feasibility and validity of the modulation strategy.

   
• Select
   Electric Power Router Based on Double DC Bus Structure

  HAN Xuenan1， SU Xiaolin1，YAN Xiaoxia1，WANG Muqing1， LIU Xiaojie2

  Electric Power Construction. 2018, 39(3): 83. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.011

  Abstract ( ) Download PDF ( )   Knowledge map   Save

   ABSTRACT： Power router is the key equipment of the energy Internet. In order to realize the function requirement of the power router, this paper proposes an power router based on the double DC bus structure. Through the low voltage DC bus and high voltage DC bus, with the interconnection of photovoltaic, energy storage, AC power grid, and AC/DC load in the form of multiport, we analyze the operation mode of the power router and the control methods of port converters, put forward the internal coordination control strategy of power router, the active response index of lateral load and the control strategy, which can realize the two-way power flow control, the port voltage stability and the selection diversification of use router. In the simulation study, three case scenarios are tested and analyzed. The results show that the proposed power router can realize the functions of power router allocation, the stable operation of the system and the plug and play of port, which can provide new ideas for the power router implementation.

   
• Select
    Frequency Control Strategy Based on Electrolytic Aluminum Load Regulation for Isolated Grids with High Wind Power Penetration

  CHEN Yuanfeng1，XU Jian1，FAN Chuanguang2，WANG Hui2，YANG Jun2，CHEN Xiwei2，TANG Chang2

  Electric Power Construction. 2018, 39(3): 92. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.012

  Abstract ( ) Download PDF ( )   Knowledge map   Save

   ABSTRACT：   The stability of the isolated grid with high penetration of renewable energy sources is becoming more and more serious. This paper studies the control strategy of stabilizing the fluctuation of renewable energy by high energy consumption load based on an actual industrial power system in the east of Mongolia. The model of a coupling relationship between active power consumed by electrolytic aluminum and DC voltage is built. The control strategy of using static var compensator （SVC） to adjust the voltage to change the active power of the aluminum load is proposed based on the voltage regulation principle of SVC. The primary frequency modulation of the thermal power unit is fully considered in the control strategy. The adjustment ability of the load is deeply excavated so that the fluctuation of wind power can be offset effectively. A calculation method of compensation capacity of SVC is proposed, which can provide capacity reference of SVC for the actual site installation. The simulation model is built on the RTDS, and the power system can maintain stability in the case of high or low permeability and extreme fluctuation of wind power, which verifies the effectiveness of the proposed control strategy.

   
• Select
   Route Construction Analysis and Overvoltage Characteristics of True Type Half Wavelength AC Transmission Line Test

  GU Peng1，WANG Ping2，HAN Bin1，XIANG Zutao1，BAN Liangeng1，ZHAO Hongga2，JIAO Chunlei3

  Electric Power Construction. 2018, 39(3): 101. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.013

  Abstract ( ) Download PDF ( )   Knowledge map   Save

   ABSTRACT：  The transmission characteristics of half wave AC transmission line is different from that of conventional line, and there is no actual project at present. Before engineering application, it is necessary to carry out the true type line test to verify the characteristics of half wavelength transmission. This paper studies the half wavelength true type transmission line based on the true type line connected with multi section 750 kV line in series, proposes the experimental route scheme of half wavelength true type transmission line and constructs the true type line test system of ‘point to grid’. Then, this paper studies the steady state characteristics of the true type line by using the electromagnetic transient and power electronic simulation program （EMTPE）, analyzes the influence factors such as the equipment along the line and the uneven parameters of the line, studies the overvoltage characteristics of half wavelength true type transmission line and proposes the control measures for overvoltage. The results show that the steady state characteristic of the true type line with multi section 750 kV line in series is basically consistent with that of the uniform half wavelength line；the arrester for 750 kV system in substations can be used to limit the overvoltage of the true type line at the permitted level.

   
• Select
   Control Strategy of Electric Vehicle Participating in Demand Side Response for Micro-Grid Operators 

  ZENG Ming1, ZHANG Ping1, LONG Zhuhan1, WU Geng1, SONG Wei1，WANG Haojing2, SUN Chengjun3

  Electric Power Construction. 2018, 39(3): 108. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.014

  Abstract ( )   Knowledge map   Save

   ABSTRACT：   Demand side response is an important means to balance supply and demand of the system in the future. As a kind of special load, promoting electric vehicle to participate in demand response is an effective way to improve response level of users and the economy of system operation. In view of this, from the perspective of micro-grid operators, considering the uncertainty of renewable energy output and load, this paper constructs the stochastic optimization model for demand side response control strategy with electric vehicles under different demand side response strategies, aiming at the minimum operating cost of the system. This model is simulated in IEEE-6 bus distribution network system. The results show that the participation of electric vehicles in demand side response can effectively reduce the total operating cost of the system, in which the implementation of the incentive based response mechanism has better economic benefits.

   
• Select
   Demand Response Optimization Strategy of Intelligent Buildings for Regional Energy Service Providers

  XIE Zhenjian1, HU Weili2, TAN Jian1, XIAO Jing3, WU Geng4, LIU Yang4, ZENG Ming4

  Electric Power Construction. 2018, 39(3): 116. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.015

  Abstract ( ) Download PDF ( )   Knowledge map   Save

   ABSTRACT：  Demand response （DR） is one of the important ways to improve the efficiency of renewable energy utilization, and to realize the bilateral interaction of future power system. At the same time, it is also an important means for future regional energy service providers to provide energy value-added services to users. This paper proposes the DR optimization model of intelligent buildings （users） for the regional energy service providers, based on the modeling of the thermodynamics characteristics of intelligent buildings. In the case study, the DR invoked mode and the original energy utilization mode are compared to verify the validity of the proposed model by taking cold storage warehouse/office for example. The results show that the proposed optimization strategy can effectively reduce the operating cost of regional energy service providers and improve the utilization efficiency of distributed photovoltaic （PV）.

   
• Select
   International Experience and Lessons in Business Models of Electricity Retailers

  YANG Siyuan, JIANG Ziqing, AI Qian, HE Qilin

  Electric Power Construction. 2018, 39(3): 123. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.016

  Abstract ( ) Download PDF ( )   Knowledge map   Save

   ABSTRACT：  In the new round of electricity market reform in China, power sales side market liberalization is one of the key contents, which encourages more participants to enter the electricity market and poses challenges to the electricity retailers operations. How to adapt to the retailing side market and succeed in the fierce competition is the primary consideration for most electricity retailers. This paper analyzes the business model and development course of foreign electricity retailers, in order to give reference for the development of Chinas retailing side competition. Firstly,  foreign electricity retailers management models are studied, including the purchase and sale of electricity, risk management, value-added services and interregional business, etc. On this basis, the typical innovative business models of typical foreign electricity retail companies are listed in specific stages of their development process. Finally, challenges are analyzed which the current domestic sales companies may face, and suggestions are proposed from experience of international electricity retailing.

   
• Select
   Feed-in Pricing Mechanism of  Distributed Natural GasGeneration Integrating Renewable Energy

  JIANG Yu1, XU Wenxiu1, SHI Jianlei1, SU Yu1, SHEN Weidong1, PANG Yuexia2, CHEN Qian2

  Electric Power Construction. 2018, 39(3): 131. https://doi.org/DOI： 10.3969/j.issn.1000－7229.2018.03.017

  Abstract ( )   Knowledge map   Save

   ABSTRACT： Combining the intermittent output of renewable energy with the flexible characteristics of peak shaving from natural gas distributed generation, this paper summarizes the multi energy complementary micro-grid system based on the development of micro-grid, which consists of wind power, photovoltaic power generation, natural gas distributed generation and energy storage system. Taking the peak shaving space and electrothermal characteristics of  distributed  natural gas,  and the uncertainty of power demand into consideration, we constructed the feed-in pricing model of  distributed natural gas integrating renewable energy, as well as the stakeholders benefit analysis model. In addition, we prove the effectiveness of pricing model with taking an energy technology center as an example. Finally, through excavating the capacity of peak shaving about distributed   natural gas  generation and analyzing the uncertainty of power demand, the pricing mechanism is conducive to reduce consumer energy expenses and promote renewable energy consumption.