Abstract:Analysis of characteristics of wind power could contribute to its integration into the grid, while high penetration of wind power has a great impact on the power grid. Based on statistical theory, this paper comprehensively analyzes wind power output characteristics, fluctuation characteristics and peak load regulation performance using measured data of Yancheng wind and photovoltaic power. Moreover, complementariness of wind power and photovoltaic power in Yancheng is studied. The above analysis supplies the evidence for utilizing the wind power in this area and ensures power system operation safety with wind power integration.

Abstract:Jiangsu province is rich in wind resources. According to the planning of government, there will be 34 onshore and offshore large-scale wind power plants by 2020, with a total installed capacity of 10,000 MW. The uncertainty of wind power has a great impact on the frequency of power grid. The pressure of frequency regulation is first analyzed and the solution is then presented in this paper. Besides, according to the situation of large-scale wind power integration, the control strategy of wind farm participating in frequency regulation is developed. To improve the control ability, the thought of wind farm and energy storage complementary system is proposed, which provides schemes for large-scale wind farms participating in frequency regulation.

Abstract:Distributed Generation (DC) is contrary to traditional centralized generation. Being the main load center of power system, urban power grid is one of the important infrastructures of city modernization, with the characteristics of high power consumption, high density of load, high reliability and high requirement for power quality. VSC-HVDC Light is a novel transmission technology based on voltage source converter (VSC) and insulate gate bipolar transistor (IGBT). In this paper, the feasibility of the distributed generation applied in urban power grid is analyzed. The VSC-HVDC technology and its application in the connection of distributed energy into the grid are then introduced, with 2 practical projects provided, which provides reference for other relative projects.

Abstract:The single-phase permanent grounding faults happened on a 500 kV line, while the protection actions on both sides are different. One side action is single-phasing switch to single-phase reclose, then three-phase trip. Another side is single-phase switch to three-phase trip. In view of this situation, graph of fault recorder and protection device action logic are analyzed comprehensively, finding that it is the different timing way of the switch protection reclosure start time lead to different actions. It is also found the reason of switches three jump for both sides is different. At last, this article proposes several ponder and hopes the relative staffs pay attention to it and use it in suitable situation.

Abstract:With automation system being widely used in substation, traditional central control panel has been abandoned and substation accident trip signals are now issued by automation system instead. However, the design of the circuit is not unified with many problems existing. In this paper, the signal loop is analyzed and summarized, combined with the problems found in the acceptance of the new substation. The conclusions have guiding significance in the substation accident trip signal design.

Abstract:In this paper two faults happened in the arc-suppression coil (ASC) system are first analyzed. For the abnormal fault phenomenon of high short-circuit impedance type post-setting ASC at field operation, according to the fault information criterion given by the manufacturer, through some electrical tests, the reason that inter-turn short-circuit fault was happened in ASC was eventually found. In another case, the false triggering and unreasonable relay configuration lead to the grounding transformer relay protection device action. Relevant data is calculated to prove the correctness of the switch action, pointing out protection configuration should be adjusted accordingly.

Abstract:Power consumption of industrial park has made up a large proportion of the whole society, so it is very important to realize intelligent power consumption of industrial park for smart grid. It can promote intelligent power consumption management level by guiding consumers in smart park to actively implement demand response. Demand response projects in smart park will produce economic benefit, management benefit and social benefit for the power grid company, consumers and the government. Taking smart parks as research object, qualitative analysis is combined with quantitative analysis, and dynamic evaluation method is used to investigate economy of its implementation. The practical result shows that it is feasible to implement demand response projects in smart park. Sensitivity analysis of related parameters is also conducted to search for key factors of improving economy of implementing demand response.

Abstract:Power system reactive power optimization problem is a nonlinear problem containing multi-variable and multiple constraints. Domestic and Foreign researchers proposed a variety of reactive power optimization algorithms, but the comparison of these algorithms is rare. In order to facilitate further amendments and to improve the performance of the algorithm, a comprehensive comparison and analysis of these commonly used methods is required. In this paper, sequential quadratic programming, improved genetic algorithm and improved particle swarm algorithm are selected. The performance of the three algorithms in treatment for reactive power optimization problem is compared based on numerical examples, and some explanation is given from the principle of the algorithm.

Abstract:The traditional connection mode of DC power system in transformer substation is unsuitable when the backup power is based on LiFePO4 batteries. The new connection mode of DC power system which separates power supply bus from batteries charge bus using an instant switch is proposed in this paper to resolve that problem. Besides, the operation of DC system under new connection mode is discussed. The data of experiment has proved that the new connection mode is feasible.

Abstract:The frequency control abilities of the Fixed Speed Induction Generator (FSIG), Variable Speed Induction Generator (VSIG) and the synchronous generator are compared and studied to achieve a more comprehensive analysis of frequency control characteristic of different kinds of wind turbines. Based on the above analysis, an auxiliary frequency controller is designed for variable speed wind turbine to improve the frequency control ability of variable speed induction generator. Simulation about the frequency control abilities of different generators is carried out on PSCAD/EMTDC platform, verifying the effectiveness of the auxiliary frequency controller.

Abstract:The automatic bus transfer equipment is important to improve the reliability of the power system. The research focuses on the overload blocking logic of automatic bus transfer in 110 kV substation with three winding transformer failing to operate in a line fault of 110 kV substation caused by 35 kV automatic bus transfer. The drawback of the overload blocking logic is pointed out in this paper. Summation and entire group lockout method and removing after the operating method are proposed. These two methods are designed to make the right operation decisions for automatic bus transfer according to the load and to avoid automatic bus transfer failing to operate. The optimized overload blocking logic of automatic bus transfer in 110 kV substation with three winding transformer can efficiently improve the security and reliability of regional power network.

Abstract:A three-phase smart meter based on SoC is designed in this paper, using MK30N512VMD100 as the main chip. The main chip build-in ADC is used to sample the voltage and current, realizing electricity metering and calculating through program. On this basis, the function of smart meter is achieved. Using main MCU chip to design three-phase smart meter, the hardware and software design is introduced and a set of design scheme is provided. This scheme can not only improve the stability and reliability of the meter, but also reduce material cost and production cost of its manufacture.

Abstract:To reduce the harmonic pollution in the grid and compensate reactive power to improve power factor, considering the single-phase circuit, the method of detecting the fundamental active, reactive current and harmonic current is carefully researched based on the instantaneous reactive power theory. A method of detecting any high frequency harmonics is put forward. Control of this method is simple and easy to realize. Simulations and experimental studies illustrate the effectiveness and feasibility of this method.

Abstract:The basic principle of circuit breaker remote control based on substation integrated automation system is analyzed in this paper. The basic process and operation method of 220 kV circuit breaker remote control are discussed and its relevant secondary circuit is analyzed. This paper also discusses the reasons of abnormal phenomena of remote control operation as well as providing solutions. It is of great reference significance for substation relative staffs.

Abstract:The feasibility of changing the overhead ground wire by live-working method is verified in this paper through stress calculation. According to the result, if the stress has exceeded the demanded level, the method of sag-easier can be used to guarantee that live-working process can be accomplished safely. Relevant calculation results are given in the end, providing reference for further use.

Abstract:Through the study of Static Frequency Converter (SFC), a new method is proposed to calculate the short circuit impedance of transformer based on the direct voltage and commutated time of thyristor. Besides, experiment was carried out on the static frequency converter in a pumped storage plant of Jiangsu province, verifying the correctness of this method. The test result indicates that the practical method has high precision and the process is convenient, with high application value. The method is also fit for that of HVDC system and excitation system.

Abstract:The problem faced by power system monitor staffs in data analysis process is analyzed in the paper. Based on the basic principle of data collection and monitor system, the effective solution is proposed. Practical test operation shows that analysis efficiency of monitoring data is improved and the workload of the staff is reduced. It provides valid reference for the improvement of monitoring data analysis process.

Abstract:The abnormal phenomenon of excitation characteristics curve of a GIS electromagnetic voltage transformer on 110 kV line is introduced. By comparing with test data from the factory, a qualitative analysis about the composite of capacitive current and inductive current is made,providing reference for the test of excitation characteristics of electromagnetic voltage transformer in GIS.

Abstract:Unit #1 of Yangzhou 2nd Power Plant was put into service in 1998. The DEH and DCS were constructed respectively using WDPF control system and TXP distributed control system. Due to the long service time, aging issues along with the increasing faulty rate may have severe effects on the safety of the power plant. A comprehensive research was conducted, and Ovation control system is employed for the integration retrofit of DCS and DEH. After retrofit, unit #1 was put into operation in July 2012, and it is found that the current key performance indicators can reach or even exceed the previous system.

Abstract:The infrared detection projects implemented in the power plants of Jiangsu Province in 2012 have been summarized in this work. The encountered problems as well as the issues associated with the field analysis, post image and data processing are presented. From the points of geographic position and plant type, suggestions, such as the typical defects frequently encountered, are proposed in this work to provide reference for technical inspection and supervision personnel. Besides, problems needed more attention during the periods of field operation and post data processing are also introduced.

Abstract:Focusing on the overlarge steam consumption encountered in the supercritical power plant manufactured using the Hitachi technology, retrofit scheme for DAS steam seal, which is intended to improve the thermal efficiency, is performed. It is expected that the clearance can be further reduced and less steam is leaked. Furthermore, methods aiming to obtain higher operating efficiency are also analyzed in this paper.

Abstract:Through integrating the induced draft fan and desulphurization pressurization fan, the reformed 650 MW coal-fired power unit can achieve lower power consumption rate. The operation economy has been improved, and it is also found that this retrofit can benefit the operation of both the boiler and gas desulfurization system. This work can provide valuable reference for the economic analysis of similar units.

Abstract:The plant introduced in this paper is the first 600 MW adjustable double-extraction heat supply power plant in China. The available experience and reference cases are limited. The intermediate heat supply pressure is maintained by the adjustment throttle employing intermediate pressure control valve. However, under this condition, the thermal efficiency of the intermediate pressure cylinder is seriously influenced by the large throttle loss, and with lower load, this situation will become even worse. The influence of intermediate pressure heat supply on the economy of the whole plant is also analyzed in this work.

Abstract:Facing the existing problems in smart grid, this paper proposes a method to combine the internet of things with smart grid. After introducing the key technologies of the internet of things, the concept and characteristics of smart grid are summarized and the network structure model for smart grid is designed. Besides, in terms of transmission, transformation, distribution and electricity consumption, relative demand is explained in detail with focus on the application of the internet of things in smart grid. Finally it is predicted that the internet of things technology will penetrate into the key technologies of smart grid, playing an active role in promoting the development of smart grid in the future.