Abstract:To improve the analysis ability of traction substation monitor system, an intelligent alarm expert system design for traction substation based on the hierarchy reasoning method is proposed. The key processes of the scheme, such as hierarchy reasoning, discrete event comparison, delay trigger and reset of rule condition, and automatic collection of panoramic information are illuminated. The proposed scheme is validated by the practical applications in several smart traction substations.

Abstract:The regional allocation of power carbon emission right is to allocate the power carbon emission right to different administrative areas. In order to allocate the power carbon emission right fairly and reasonably, the index system for power carbon emission right should be established. Based on the literature review, the influence factors are found out. On this basis, a index system which includes 3 levels and 14 indexes is proposed. This index system considers the characteristics of China's power industry and administrative, which provides a theoretical support for the regional allocation of power carbon emission right.

Abstract:This paper presents a statistical analysis on lightning activities in Jiangsu province in 2014. The trend of lightning times and geographical distributions is analyzed. Combined with the lightning location system recording data, the lightning trip times, trends, failure forms and lightning tower structural features are analyzed, and the reasons for all the lightning trip cases are obtained. Lightning protection suggestions for earth resistance measurement, comprehensive lightning protection measures application, GIS systems and lightning location system data arranging are provided.

Abstract:A 500 kV autotransformer longitudinal differential protection malfunction caused by an external single phase fault is introduced in this paper. The Differential protection principles of the imported equipment are studied, and the reasons for the malfunction are analyzed. Improvement recommendations is presented for similar protection devices in the power grid.

Abstract:Existing insulation operating arm does not have specialized rescue knife. When dealing with extra matters of large size or hard materials, the destructive effect is not satisfied-time and strength consuming, so as neither the security nor stability of the power network can be guaranteed. A design of the multi-function device for extra matters disposal for transmission line is proposed to solve this problem. The device is connected to the combination of the screw and the limited phase, so as to strengthen the operating arm. It is also equipped with different kinds of operations by adopting different materials. The experiment results show that the new foreign body processing device improves the reliability of the network effectively in terms of saving operation time and reducing labor intensity.

Abstract:In recent years, the number of the hybrid transmission line fault location problems raises due to the increasing numbers of cable lines. This paper proposes a new hybrid transmission line fault location method based on the percentage of line calculation. A more reliable and accurate calculation method based on distributed parameter model is proposed. The fault location is determined by calculating the percentage of each line segment, in which sequence component method is used to solve the fault distance without double-ended synchronization data. The two-terminal-data method can effectively overcome the disadvantage of single-terminal-data method which is easily affected by power system operation states and parameters. Simulation results show that the proposed method for fault location is reliable, effective, and accurate. The proposed method is promising in engineering applications with the growing number of cables.

Abstract:Early production and operation of the Huainan-Shanghai UHV project will form a 1000 kV/500 kV/220 kV electromagnetic loop network along the Jiangsu UHV, which has an impact on the short-circuit current of power grid. BPA short-circuit current calculation result shows that after UHV's access to the Jiangsu power grid, the short-circuit current of the 500 kV bus in Shipai and the 220 kV bus in load intensive subsystem of western Suzhou increases in different degrees. According to the phenomenon, a short-circuit current suppression measures based on the strategy of dynamic partitioning including unlocking the electromagnetic loop network and load transfer is proposed, along with the analysis of actual examples. Case analysis verifies the reliability of the proposed current limiting measures, and provides a reference value for reducing the short-circuit current in engineering practice.

Abstract:Errors of network parameters can severely affect the performance of state estimation and degrade the usefulness of other advanced applications in an energy management systems (EMS). It is important to develop a practical suspicious branch set selection method. Due to the deficiency of the traditional method which only considers the branch measurement residuals, a parameter error identification considering distance space is proposed, which takes the adjacent branch and peripheral branch into consideration. At the same time, the standards residual of different branch distance measurement are assigned with different weights, which facilitates the sorting comparison of different operation mode and measurement placement branch. Finally, the IEEE standard test system and a provincial power grid are adopted to verify the usefulness of the proposed approach, and the comparison results between the proposed method and the traditional parameter error identification method illustrate that the proposed method performances better.

Abstract:Electrical equipment and materials planning, procurement, storage and distribution are the basis of project operation of power systems. The research and application of material management of ERP power model provides a powerful guarantee for the operation of power grid enterprises. The requirements of power supplies inventory protocol program and the distribution pattern of research and design are analyzed. Three kinds of distribution modes are proposed, and their corresponding mathematical formulations are established. On the basis, the software to aid costumers distribute power materials is designed according to the proposed approach. Example results show that the proposed approach is effective and improves the efficiency of power materials management.

Abstract:High voltage series reactor has become an important equipment for current-limiting in recent years. This paper takes Nanjing 220 kV-power-grid as an example. The short-circuit current level of Yaohuamen is out-of-limit. This paper selects the appropriate location and number for high voltage series reactor. Then analyzes the effects after its installation. It is found that high voltage series reactor effectively reduces the short-circuit current in Nanjing 220 kV-power-grid.

Abstract:Nowadays the settings of relay-protection devices in substations are constantly increasing and becoming more and more complex. Therefore, the checking work for settings is increasingly complicated. This paper presents a method to traverse the firewall and download remotely. In the method, WEB servers of the provincial company can be accessed in web form, and consequently access can be downloaded. At the same time, this system integrates protocol modules of various manufacturers, directly connects devices and reads settings. The system can help maintenance personnel to check settings of 220 kV relay-protection devices very easily in substations. It can improve working efficiency and correctness of setting check. It also can prevent accidents of wrong configuring settings. The checking system is portable, easy to use, and suitable for checking work. This system has a realistic sense and can be widely used.

Abstract:The power system model with reasonable network is needed for PAS. In the current EMS, the correctness of the topology, the completeness of the device parameters and the diversity of the model are not included, which makes PAS analysis unable to execute. Targeting at the disadvantages of PAS network model and its application, a new modeling process design is proposed. The proposed design meets the usage requirements of different PAS applications and heterogeneous operating system platform. In addition, the design is reusable and based on multi-platforms. Software developed based on the proposed design is applied into several China's dispatching control systems. The applications show that the proposed design can meet the requirements of PAS application.

Abstract:In order to adapt to the flexible application requirements of relay devices in fields, a novel graphic configuration program is developed based on the Qt software. The design scheme and developing frame is introduced and the realization of editable graphic components, configuration validation check, project compiling process, and modules design are explained. Finally, this developed tool is applied in relay devices development.

Abstract:This paper presents an evaluation model to reflect the value brought from multiple competitive electricity markets throughout the analysis of the impact of multiple time-scale markets on wind power integration. This model is capable of optimally allocating the resources of power grids and promoting high wind power penetration by means of market measures. The proposed electricity market model consists of the day-ahead market, hour-ahead market and real time operation adjustment. Stochastic programming is used to model decision-making under wind power uncertainty, to evaluate the value of the available resources in this three time points. Furthermore, multiple time-scale coordination market clearing can be obtained at the corresponding time points. Numerical simulation demonstrates that the presented market framework can mitigate the uncertainty of large-scale wind power, leads to a reduction in system reserve requirements, and be beneficial to the optimal operation of a power grid.

Abstract:This paper proposes a new simulation technique for digital spare power automatic switching. The technique analyzes the logic of digital spare power automatic switching based on power system dynamic topology. The simulation software based on Sophic platform is developed using the proposed technique. The developed software is deployed in a distributed fashion and is used in the simulation environment which do not affect the normal functions of SCADA. The simulation technique has been applied in Hong Kong Chui Ling Road station, which achieves the expectation.

Abstract:In order to reduce the APF control error caused by sampling rate, a method of predictive hysteresis control based on current prediction is proposed. The cause of hysteresis control error is analyzed. On the basis of the active filter dynamics model, output current prediction model is established, the target current is predicted by linear interpolation, and the working principle of this control method is introduced. A controller system is designed based on the CompactRIO. The experimental result comparisons between the proposed method and traditional hysteresis control show that the proposed method is effective in reducing control error.

Abstract:The continuous expansion of power system makes the same tower double-circuit or more-circuit transmission lines becoming the development trend of transmission network. The induced voltage and current is generated by the two or more transmission lines on the same tower or the electrostatic and electromagnetic induction effect of adjacent parallel arrangement of overhead transmission lines. In this paper, the calculation formula for induced voltage and current of double-circuit transmission line is provided. Also, main factors affecting induction voltage and current are analyzed. The applications of parameters calculation of some typical simulation software, such as ATP-EMTP, EMTPE\EMTS, MATLAB\Simulink are introduced. An example of calculating the induction voltage and current of a 220 kV double-circuit lines on the same tower is provided, and the limits of previous mentioned simulation software are summarized.

Abstract:For the purpose of compact structure and simple network design in smart substation, the integration of merging unit and intelligent terminal at the process level becomes a new trend in the smart substation. A new software and hardware solution for the integration of merging unit and intelligent terminal is proposed in this paper. Base on this scheme, not only the requirement of the integration of merging unit and intelligent terminal can be met, but also the transmission time delay from input to output of the analog data is shorten and the data transmission speed is improved. The transmission time delay less than 2 ms which is defined in related standards. It also improves the operation time of the protection devices connected to this new device.

Abstract:Standard oil can be used to calibrate on-line monitoring chromatograph. Nowadays, there isn't an appropriate device to storage and transport the oil. A portable standard oil saving device is developed in this paper. The device adopts the design of internal capsule and pressure storage method. The oil conglutination on the inner wall is avoided, and the gas do not escape from the oil. Compared to the traditional saving devices, the new device's preservation effect is better, and its preservation time is extended from 4 days to 180 days. The stability of standard oil in any environment is guaranteed, which fulfills the standard of transformer chromatographic analysis. The device provides a reliable reference for transformer on-line chromatography monitoring.

Abstract:As the main adjusting method for reducing NO_x emission, the adjusting strategy of SOFA system is essential for boiler operation. Using 600 MW supercritical coal-fired boiler as the research object, analysis on the influence of SOFA system on the boiler efficiency, the NO_x emission, and the operating cost has been carried out based on combustion adjustment tests. The results indicated that variable adjusting strategies for SOFA system should be adopted under different loads.

Abstract:Analysis on the low reheat steam temperature encountered in one 330 MW drum boiler was performed from the aspects of coal characteristics and heat supply capacity. The countermeasures of increasing the heat transfer area of the reheater was then proposed, based on the detailed investigation of the practical effects of previous retrofit efforts. The anticipated effects were finally achieved.

Abstract:To further decrease the amount of pollutant emission, a new wave of retrofit efforts for environmental protection are being performed. Operating principles and technical features of the three different kinds of wet electrostatic precipitators (WEPs), including the flexible electrode WEP, the metal electrode WEP, and the glass-reinforced plywood WEP, were introduced. As for the glass-reinforced plywood WEP, the structural forms and characteristics were introduced in detail. The research efforts of the present work can provide valuable reference efforts for the coal-fired power units to select reasonable electrostatic precipitators.

Abstract:Taking the application of agglomerator in the electrostatic precipitator retrofit of one 135 MW power unit as an example, this work introduced the operating principles and technical features of agglomerators in detail. After performing retrofit, we found that the collection efficiency of the electrostatic precipitator had been significantly improved, while the concentration of the outlet particles had been reduced by about 30%. The investment as well as the operation and maintenance costs of agglomerator is relatively low, while the retrofit period is also not too long. Thus, it is believed that agglomerator can benefit the technical retrofit of electrostatic precipitators in old thermal power units.

Abstract:In order to improve the two-way interactive ability between the power grid and users, and realize the delayering, fining and coordinating of business of electrical marketing, real-time transformation, convenience and centralization of administrative decision, a system designing scheme of mobile marketing based on the Internet of Things technique is proposed. This system consists of mobile marketing interactive platform, mobile marketing interactive terminal and communication system. Mobile marketing interactive platform and mobile marketing interactive terminal are built on standard and universal hardware platform, which contains mobile work, mobile control, mobile service and mobile communicating in function, and then a business integration mode of cross application is presented, which realizes the weak coupling between business and dada, promotes the Convenience and Scalability of the platform, and then enhances the efficiency of business development.