Abstract:According to the technical characteristics of amorphous alloy transformer and the application of Jiangsu power, the comprehensive evaluation about amorphous alloy transformer from the safety performance, the economic performance and the environmental impact are studied comparing with S11type, S13 type and S15 type transformer. In the safety performance, overload capacity and over-excitation ability of amorphous alloy transformer is insufficient; in the economic performance, low no-load loss, high efficiency, energy saving effect of amorphous alloy transformer is obvious; in terms of environmental impact, the audible noise level of amorphous alloy transformer was higher than that of conventional transformer, manufacturers need to study to reduce the noise level. Finally, the application recommends of amorphous alloy transformer is presented based on comprehensive evaluation.

Abstract:The forecast of wind speed and solar irradiance is very important for the stable and economic operation of grid-connected hybrid photovoltaic-wind power generation systems. The original weather generator is improved to make it more accurate and meet the demand of probabilistic production simulation of power system including hybrid photovoltaic-wind power generation systems. Afterwards, a combination forecast method of wind speed and solar irradiance is proposed. The method models the complementary characteristics of solar irradiance and wind speed based on the historic daily observation data, and then obtains the forecasting result at hourly intervals. The simulation results show that the model can be used to accurately predict and in engineering practice.

Abstract:This paper analyzes the results of partial discharge test in a 220kV transformer. The partial discharge position is preliminarily located by plurality of terminal correction-measurement method. After further analysis combined with the characterizing parameters of partial discharge in high voltage winding of the transformer, the reason of abnormal result of partial discharge test is determined, namely the bubble discharge in oil. This article also provides on-site treatment scheme and suggestions on transformer installation process in winter in Jiangsu province.

Abstract:Through the analysis of heavy gas protection malfunction on closing no-load transformer, and then taking reference on the similar cases happened in recent years, this paper finds that secondary circuit failure, transformer vibration and oil flowing caused by magnetizing inrush may lead to heavy gas protection malfunction. The measure is proposed to reduce the possibility of heavy gas protection malfunction caused by the transformer inrush current and magnetizing inrush of transformer in different closing angles situations is simulated. This article also proposes that eliminating magnetizing inrush by precise control of the closing angle is theoretically possible. Based on the analysis above, the proposed measure can decrease winding vibration and oil flowing caused by the impact of current in transformers.

Abstract:Firstly, the problems encountered in the remote transmission of HVDC control and protection TFR files are described and discussed. And then a new way is proposed. In the new situation, a front equipment machine is added to the HVDC control and protection system which can get TFR files from HVDC control and protection system through disk mapping and transfers information to the remote dispatch center through dispatching data network and IEC 61850. This way has been implemented in real HVDC projects.

Abstract:In view of the problem that the automatic drawing and checking, announcing and query, updating and managing of main wiring graph, the paper provides a design method of drawing synthesis management system combining C/S and B/S. This method can realize synchronous update of main wiring drawing. When automatic drawing and checking system for main wiring graph put into operation in Guangdong power grid, it can improve the degree of drawing rate, accuracy and standardization of graph.

Abstract:Reasons for poor current-sharing of rectifiers for generator excitation, including AC Impedance, component on-state characteristics and busbar connection mode, are analyzed. This paper proposes relevant solving method that is rearrangement of the order of SCR, redesign of main circuit busbar, installation of flux diverter and digital intelligent current-sharing, achieving good results in practical application.

Abstract:In recent years, domestic electric vehicles gain more popularization and application. However, it is deficient in research of operation charging mode about the battery swap electric bus, and there is no corresponding successful commercial operation case. This paper analyses the present charging situation of charging and swapping battery service. Taking the battery swap electric bus in preferential policy city as an example, in consider of depreciation of charging and swapping station, the cost of battery, the service of charging and swapping and so on, this paper analyses the balance of investment and profit, to calculate charging and swapping service charge standard. Comparing with the charge standard of oil-alternative in part provinces, conclusions and suggestions on charging battery swap service are then given, which provides reference for the research and release of domestic electric vehicles charging and swapping service toll standard.

Abstract:The conventional Automatic Voltage Control (AVC) system, in which the bus voltage and gate power factor are set as control targets, can improve the qualified rate of voltage and power factor. However, it is lack of economy in reducing the network losses; On the other hand, the reactive power optimization algorithm that minimizing the network losses can obtain the optimal solution in theory, but it is too ideal to apply in engineering. This paper proposes a zone strategy-optimization method for the purpose of engineering applications in regional power grid, also considering the security, stability and economy. This method can obtain the coordination control effect between substations, and get optimal strategy for current zone. Multiple engineering applications achieved good operating results, showing that the algorithm is advanced and has a certain popularization value.

Abstract:Based on the analysis of existing implementation technology of anti-theft and anti-malfunction in medium distribution substation, new technical scheme is proposed. Adopting novel intelligent lock-key device and GPRS or 3G VPN wireless communications mode to transmit information, and can realize multilevel authority management of anti-theft key. Moreover, human faulty operation can be prevented through anti-malfunction data model using neural network.

Abstract:Based on the requirements of the regional power grid and real-time optimal control of the whole network economic operation, this paper proposes a design scheme of an assistant decision-making system for economic dispatch used in regional power grid. This system can provide real-time assistant decision for economic operation mode of power network by online analysis. It can be also used in network loss statistics and off-line analysis to take measures to reduce losses.

Abstract:With the advantage of high energy efficiency, variety using types and solving energy demand on the spot, combined cooling, heating and power (CCHP) micro-grids can satisfy the demand of integral energy users compare to normal energy utilization types. However, CCHP projects in operation or under construction currently are often unreasonable allocated, the energy utilization efficiency of the systems are far lower than the expected, and the production efficiency of the devices is low. The optimal model of capacity planning for CCHP micro-grid is proposed in this paper. Firstly, several typical types of cogeneration micro-grid systems are introduced. Then, the optimal model for capacity planning of CCHP micro-grid is built. Finally, the model is realized in CPLEX language and the effectiveness of the model is verified by example analysis.

Abstract:This paper studied a new type of Q460 high-strength narrow-base four-column steel pipe tower for 220/110 kV mixed voltage 4-circuit Transmission line. Examining the steel consumption, vertex deflection and natural frequency of structure, the structural optimization and analysis on leg spans and beam intervals are carried out. The reasonable values and selection method of the leg spans and beam intervals of 220/110 kV mixed voltage 4-circuit narrow-base steel pipe tower are proposed.

Abstract:Large numbers of nonlinear loads of metallurgy enterprises connected to distribution grid have significant effect on system power quality. After introducing the electrical characteristics and harmonic emission levels of typical nonlinear load, this paper presents the harmonic superposition method of different types of harmonic sources. Combined with power quality test results in Changzhou area, the specific harmonic effect of metallurgical enterprises on power grid is then analyzed, and corresponding measures are also proposed.

Abstract:For two main transformers in one power substation, if the capacity of one transformer is not equal to another transformer's or less than the total power load of the substation, the action of automatic switchover device will cause the transformer with smaller capacity overload. However, the action of automatic switchover device with current blocking will cause extensive load loss. Based on the detailed analysis in the shortage of the overload management in traditional automatic switchover device, a novel method of automatic switchover device for traditional and smart substation is proposed based on self-adaptive electrical load.

Abstract:Due to difficulties in power supply of field monitoring device and wiring complex, the current temperature on-line monitoring systems for power cable can't be used in large scale. This paper proposes a temperature monitoring system based on wireless technology, with characteristics of low power consumption and easy expansion. SmartNode module composed of short-range wireless sensor network is used to realize acquisition of cable connector temperature and data transmission. Field operation by Power Supply Company indicates that the hardware and software of this system are at normal operation, with good networking and transmission performance. The system is proved to have strong practicability.

Abstract:Due to the fact that 220 kV transformer protection configuration has been set by manufacturer, the conventional setting cannot satisfy system operation requirements. For different site-specific protection configuration, using different schemes of 10 kV back-up protection relevant tripping circuit of breakers on each side of transformer, the problem of 220 kV side back-up protection without the sensitivity can be solved. The practical application in the field gets good results.

Abstract:In smart substation, the implementation of anti-maloperation system has heavy workload but low efficiency. This paper presents a method of automatic generating devices' five-prevention rules during the drawing of the main-line diagram for whole substation. The primary equipment graphic objects based on G language could be connected seamlessly to IEC 61850 based model data objects, thus rules files used by anti-maloperation devices could be generated from primary device topology directly, avoiding complicated input configuration of rules database. This method is helpful to increase efficiency and quality of smart substation project implementation.

Abstract:When changing the transformer substation's analogy channel to network channel, intermittent problem and interrupt problem will exist in some substations channel. This paper analyzes influencing factors of substation channel from keepalive quality and serial port quality of TCP, and then the solution is proposed in order to guarantee the normal operation of substation when network reform.

Abstract:The healthy development of distributed photovoltaic power generation is dependent not only on the guidance and incentives but also the norms and constraints of polices. The policy recommendations of grid integration of distributed photovoltaic power generation in Jiangsu province is proposed, referring the feed-in tariff policy, the net metering policy, the cost-sharing policy, the grid integration technical regulations in developed countries, combined with the existing grid integration policy of distributed photovoltaic power generation in our country.

Abstract:Two types of 1 000 MW ultra-supercritical steam turbines installed within Jiangsu Province are analyzed in this paper. The differences between the structural features and performance design parameters of these two types of steam turbines are introduced firstly, and then the root reasons leading to the deviation between the actual performance and initial design parameters are analyzed qualitatively. This paper can provide valuable reference for the type-selection of steam turbines as well as the operation and reform of power units in service.

Abstract:Issues associated with the frequent pressure fluctuation occurred in main pipes transporting compressed air, frequent switching of air compressor as well as unstable pressure of the air supplied for instrument are encountered in one thermal power plant. Through referring to the field operation curves, root reasons for these mentioned issues are analyzed in this paper. Based on related calculation results, basic requirements for reforming the pipeline system are analyzed, and reform scheme suggesting the installation of buffer air storage tanks is proposed. Effectiveness of the proposed scheme is illustrated with the operation curves obtained after reform.

Abstract:The large scatter of the fineness of pulverized coal, serious boiler slagging phenomenon as well as high carbon content in fly ash have seriously influenced the safety and economy of the coal-fired power plants of Guoxin Yangzhou Power Generation Co. Ltd. Reform of the rotary separator of No. 4 coal mill is thus performed. The reform scheme, structural features and the post-reform experimental validation are also introduced in this paper. The practical operation results show that several of the above mentioned questions can be solved effectively.

Abstract:It is encountered in one 135 MW thermal power plant that, during the start-up processes, the desired quality standard for condensed water, feed water and deoxygenated water can hardly be met satisfactorily. In order to prevent the corrosion of boiler and related pipelines, this work firstly introduces and analyzes the corrosion mechanism and the hazards resulting from substandard water quality. The causes of above mentioned problems are then summarized, and solution measures that can be performed in field are also proposed. Finally, the effectiveness of these measures is illustrated through comparing the statistical data.

Abstract:Data transmission is an important part of system power quality. This paper summarized the current network structure commonly used in power quality monitoring system, as well as describing PQDIF and IEC 61850 standard from aspects of characteristics, structure and using defect. This article also pointed out their respective pros and cros in data definition, amount of data transmission, transmission mode, function realization and difficulties of development.