Abstract:It's important to explicitly consider transmission losses under the circumstances of large-scale new renewable energy integrated into the power gird. A modified DC power flow method, which is more precise compared with the traditional DC power flow, is proposed. Based on the proposed DC power flow, a new economic dispatch method considering transmission losses is proposed. The proposed method improves power re-dispatch accuracy, as well as keeps the advantage of the convergence of DC power flow. Simulations results on IEEE 30- and 118-bus test systems show that the proposed method is effective.

Abstract:In order to improve the accuracy of wind speed prediction, a wind speed prediction method based on GA-BP is proposed. The proposed method divides original data into different periods of time to improve training sample's similarity. Simulation results show the absolute error of GA-BP decreased and its accuracy promoted. Furthermore, the accuracy of the prediction becomes more accurate after original data processing. Therefore, the proposed method improves the performance of wind speed prediction, and it provides more accurate gist for wind power grid scheduling control.

Abstract:The achievement of the fast cut back (FCB) function of thermal power units is of importance for fast restoration of power grid to reduce the loss after power blackout. Through analyzing the status of FCB function applications of thermal power plants around the world and the relevant experimental studies in domestics, the inadequacies in the application and research of FCB function for power grid black-start in our country are summarized. The main influential factors of achieving FCB function in thermal power units are studied. The study is aimed at providing references for promoting the research and construction of FCB function of thermal power units and the application of the FCB function in grid black-start and in China.

Abstract:Disconnector is an important transformation/distribution device in the power systems. Effectively solving the common faults of disconnector will definitely improve the reliability of power supply. Targeting at a common crack of the driving block in disconnector operating mechanism, an acceptable scheme to eliminate this kind of defect is found after analysis on the crack and comparison of improvement measures.

Abstract:For checking the splitting crack of double-umbrella porcelain insulator in the 220kV transmission line tower, detections on deterioration of insulators have been implemented. 6 electrical performance tests, related to insulation resistance, industrial frequency spark, temperature cycle, mechanical and power coordination, oil breakdown and porosity, on the double-umbrella porcelain insulators from a same factory are employed. Test results show that problems exist in the insulators due to process defects. We recommend that strengthening the detection of the double-umbrella porcelain insulators to avoid unqualified insulators to be used in the power grid to threaten power system's security.

Abstract:This article introduces the failures of bearing vibration climb in No.5 and No.4, bearing relative axial vibration step in No.7, etc. We conduct multi kinds of vibration tests, study relation among the steam machine forced vibration amplitude, the exciting force and the dynamic rigidity of the support system, analyze the vibration mechanism and adopt various ways of absorbing vibration, which shows the right way of solving the vibration failure for the same power unit.

Abstract:With the development of computer and communication technology, investigation of on-line monitoring for relay protection system has made important progress, and could solve the over-maintenance problem caused by the traditional time-based maintenance approach. The paper promotes system-level solutions for on-line monitoring of relay protection system and related device in the intelligent substation, defines state-detecting information of protecting device and corresponding transmission mode, and designs on-line monitoring scheme for physical link and logic link of secondary circuit in relay protection system. Finally, engineering application of on-line monitoring for relay protection system in the intelligent substation shows that the solution can accomplish on-line monitoring on relay protection device and secondary circuit, which effectively increases the reliability of relay protection system.

Abstract:In order to decrease transmission losses, double-line parallel operation mode is adopted in some high voltage direct transmission (HVDC) projects. However, only one line fault locator is configured due to the investment consideration and the limit of mounting position. Aiming at solving this problem, a fault line selection strategy is proposed based on the AC fault line selection experience and the analysis of the characteristic of DC line fault. The strategy is divided into transient fault line selection, rectifier steady fault selection and inverter steady fault selection. The proposed strategy is validated by real-time digital simulator (RTDS) system.

Abstract:According to the characteristics of 500 kV standard distribution-mode smart substation, an optimization design of station power system is proposed. The optimization design includes reasonable allocating the lighting and power load, decreasing the capability of the station transformer, selecting amorphous alloy backup transformer, and decreasing the investment on station transformer. Combining with the re-configuration of the secondary-equipment-chamber, a radiant system is design to reduce the section area of cable and the difficulty of construction.

Abstract:Currently the conversion efficiency of PV cell is poor. The maximum power output tracking for MPPT is needed to improve energy efficiency. To deal with the defects of poor rapidity, low precision and poor adaptability of the conventional MPPT, a method based on improved single neuron adaptive controller is proposed. The simulation results show that the method can track the maximum power point rapidly and accurately and has a strong adaptability to the environment change.

Abstract:There are many kinds of phase shifting transformer (PST) because of the wide variety of applications. Therefore, the differential protection of the PST are different. This paper analyzes the differential protection of PST and sum up the typical type of it. Based on two fundamental differential protection principles, this paper proposes a series of differential protection configuration for typical PST. The protection scope, fault type and matching relation of different protection are analyzed base on theoretical analysis and RTDS simulation.d RTDS simulation.

Abstract:Security protection is a key technique of the dispatch and substation integrated system. From the point of view of security risks in dispatch and substation integrated system, taking remote maintenance as an example, a method based on double-factor login, digital certificate and right authentication for security protection has been designed. Firstly, login with a double-factor strategy makes sure its safety. Secondly, communication packet must be signed and verified. Finally, verifying user's access right in the substation. These measures enhance the system to resist risks in dispatch and substation integrated system.

Abstract:The development of the communication technology makes it possible of integrating the sampled value (SV) network, generic object oriented substation events (GOOSE) network and manufacturing message specification (MMS) network for the bay level, the process level, and the station level (three-level-in-one-network). A new developed protective device for this integration can realize the grading and separate treatment of the network data. Meanwhile, this new device can network with the corresponding switch, which can solve the data synchronization problem under the three-level-in-one-network condition, thus the problem of the data reliability and availability of the protective device can be solved. Under the three-level-in-one-network structure, this device can meet the requirements of protection and control in the smart substation. The reliability of this new developed protective device already has been verified by relevant tests.

Abstract:The paper presents a two-stage power flow calculation method for the distribution network with loops. In the first stage, the meshed network is converted into a pure radial network by applying the superposition principle. Then the forward/backward sweep method is employed to attain the voltage differences across the loop switch of the radial distribution networks. In the second stage, continuously modifying the load power across the loop switch, the forward/backward sweep method is employed to attain the power flow of the radial distribution networks once again and finally tends to the global convergence. Last the iteration method is used to attain equivalent impedance of the high-voltage power grid. Simulation results on some actual distribution grids verify the astringency and accuracy of the proposed method.

Abstract:This paper introduces the helicopter inspection technology for 500 kV and above transmission lines and its application in Jiangsu power grid in 2013. Comparative analysis on the results and benefits shows there is little difference between human inspection and helicopter inspection in inspection fee, but the helicopter's inspection efficiency is 6 times of the manual inspection approximately. The helicopter inspection technology can be applied into the supervision inspection for 500kV and above transmission lines. It can reduce labor intensity works, improve the quality of inspection, reduce the cost of maintenance and improve operation security of transmission lines.

Abstract:In this paper, taking the 220kV Qinhuai substation-Binnan transmission line uprating project as an example, the method of using tension machine to roll old wire and replacing carbon fiber wires are introduced. A "two pulls one" draw plate is designed to fix the end of net sleeve. Due to the use of new carbon fiber device, construction efficiency is improved for engineering application.

Abstract:This paper introduces the concept of the supervisory information system of power plant level (SIS) and the typical B/S system architecture. From the point of views of system structure, data acquisition, communication interface, software application, security and other aspects, the design method SIS is interpreted. In addition, a design scheme of the typical B/S system architecture is provided. The proposed scheme is validated by its applications in many thermal power plants.

Abstract:DC system is an important part of power plants or substations. Reliable operation of DC system is critical to power grid security, stability and continuous operation. In recent years, a large number of new technologies and new equipment have been applied to the DC system. Therefore, exploring the hidden danger of DC system has a very practical implications. This paper analyzes the status of equipment operation, monitoring, maintenance in DC system. According to the operation experience and the state grid's safety regulation, this paper proposes a new method for hidden investigation in DC system. The method not only ensures reliable operation of DC power supply equipment, but also brings economic and social benefits.

Abstract:This paper introduces the current status and structure of the distribution communication network in Wuxi. The overall objective, technical route, networking principles, and network structure of Wuxi communication network are presented. Moreover, the existing problems in the construction of communication network are emphasized, the distribution route planning objectives and technical requirements are proposed, and the construction goal as well as development direction of distribution communication network Wuxi is clarified.

Abstract:In view of increasingly severe energy environment issues, higher requirements on energy-saving and emission reduction. Current development of Jiangsu power, the technical approaches for energy-saving and emission reduction of Jiangsu power are analyzed and presented from power generation ,transmit electric power, converting electric power, distribution electric power, electric power dispatching ,and application of energy-saving and emission reduction electric power technology.

Abstract:To address water-wall corrosion in utility boilers particularly super-critical boilers with low NOₓ combustion, the achievements and experiences of USA studies in corrosion mechanisms and mitigation technologies are systematically reviewed. The main corrosion mechanism is: the deposition of FeS on water-walls under reducing atmosphere and the subsequent FeS decomposition and oxididation on the walls under alternating reducing/oxidizing atmosphere cause severe corrosion. While refined combustion optimization can promote in-flame FeS oxidation to alleviate corrosion, enhancing corrosion resistance of the material through thermal spray and weld overlay is effective measure.

Abstract:The characteristics and mechanism of steam-exited vibration fault were discussed in this paper. At a high load, larger half-frequency vibration occurred in NO.1 and NO.2 bearing of one 660MW steam turbine. Based on the further analysis on the frequency spectrum of valve test and vibration characteristics, it was deduced that the vibration was caused by steam-exited vibration. By adjusting the valve and the elevation of NO.1 and NO.2 bearing, we basically solved the turbine vibration.

Abstract:For low vacuum phenomena of power plant turbine condenser conducted a detailed study ,analyzes the open cooling unit condenser fouling characteristics and economic impact on the unit, though the WSD line cleaning robot technology application practices and operating data analysis and comparison to prove that the technology to solve the open cooling unit condenser fouling problems, improve the economic performance of the unit has a significant effect on the same conditions hereinafter set of application types have profound reference.

Abstract:The large pressure difference of the air preheater observed after performing denigration transformation in the Guoxin Yangzhou 630 MW power unit is introduced in this paper. Through analyzing the flushing results, it is found that flushing processes employing high-temperature high-pressure water can effectively remove the ammonium bisulfate ash and thus solve the clogging problems frequently encountered in air preheaters. Besides, measures including increasing the cold-end temperature of the preheater in winter, controlling the ammonia escape rate, and regularly performing high-pressure flushing when the preheater is undergoing high load, are also proposed.

Abstract:After decades of development, China's nuclear power generating unit reliability has been greatly improved. The equipment management and human factor management countermeasures and practice for improving the reliability of unit taken by the nuclear power is introduced in this paper. On the basis of the analysis of the unscheduled shutdown of the status quo of thermal power unit in recent years, strategies to enhance the reliability of generator equipment are proposed. Drawing lessons from the nuclear power industry management experience can promote the production management of thermal power generation enterprises and reduce the times of unscheduled shutdown.