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The following topics are dealt with : distribution system; dispersed generation; risk assessment; power system reliability analysis; power system stability; power system control; energy access and power electronic device; power system protection; power system automation; power system economics; and critical infrastructure analysis.
At present, the small analog signal transmission is adopted between process level and bay level in most of the digital substation systems below 35kV. Considering the characteristic of the structure and the special request for the earth fault line selection device, the design of line selection device is proposed for the digital substations. With distributed structure, the device consists of two parts,...
Future smart grids will enable increased energy efficiency due to utilization of vast amounts of Distributed Energy Sources (DER) and Renewable Energy Sources (RES) partially controlled by empowered customers. Smart generation and distribution systems will connect energy providers with customers and other stakeholders utilizing new kinds of smart monitoring, coordination and data management infrastructures...
The importance and necessity of economic loss evaluation of power quality is discussed in the paper. In order to scientifically evaluate the economic loss of power quality indexes, the idea of meaningful classification of power quality problems is emphasized and the quality loss function is introduced into the evaluation models. According to the characteristics of continuous power quality problems,...
The faults in electric power system can not be completely avoided. When power system operates from normal state to failure or abnormal operates, its electric quantities may change significantly. Our researches indicate that the variable with the biggest coefficient in principal component usually corresponds to the fault. Therefore, utilizing real-time measurements of PMU, basing on principal components...
Wind power penetration to power systems is increasing rapidly in the recent years due to its environmental benefit, while wind power fluctuation also brings some problems to power system operation which impacts the transmission company's willingness to accept wind power. The most serious conflict influencing wind power development is that the currently adopted price of wind power on-grid does not...
The scale of medium voltage networks have been expanding and cables are increasingly used so that nowadays capacitance currents are much greater than before when single line-to-ground faults happen. And the harm of an arcing ground overvoltage is extremely severe in an ungrounded system. To solve the problem put forward, the neutral of a medium voltage network is grounded with petersen coils or low...
Single-phase Auto-reclosing (SPAR) is widely used on EHV/UHV transmission lines to improve power system reliability. However, reclosing on to a permanent fault can adversely affect the system stability and damage generators and other equipment connected to the line. To solve this problem, a new algorithm for improving the single-phase adaptive autoreclosure is presented in this paper. Firstly, primary...
The structure of Static Var Compensator (SVC) control system and compensation principle is briefly analyzed in this paper. Based on the control method of nonlinear norm transformation PID, a novel method for SVC using nonlinear slope reactance is presented. The simulation results show that the method can accelerate the stabilizing process and reduce rising time and overshoot obviously.
At present, micro grid has gradually become the trend of distributed energy applications. View of battery energy storage of PV generation system in micro grid; research the battery energy storage system discharge characteristics and the realization of simulation. Simulation models are designed based on PSCAD / EMTDC platform, corresponding control strategies. Set up the equivalent model and design...
Due to the large amount of branches and high grounding resistance of the distribution network, the earth fault location has not been solved effectively. A live location method is proposed for the single-phase-to-earth fault section in the neutral point resonant grounded system. By this method, the compensation current of arc-suppression coil is adjusted after the metallic earth fault occurs. And the...
The value setting of the traditional distance protection has become very difficult for the distribution system with distributed generators (DGs) owing to the randomness of the DG output power. This paper proposes a new adaptive distance protection scheme to solve this problem. Firstly, on the basis of the connected point of DGs, the protected feeders are divided into different zones, with adaptive...
In a liberalized electricity market, it is not surprising that different customers need different power quality levels with different price. So how to achieve the synthetic grading evaluation of power quality becomes a concerned problem. In this paper, the idea of classified evaluation of power quality is emphasized, and the major differences between the continuous and event-based power quality problems...
To solve the distributed generation system (DG) voltage regulator problem, this paper introduced the thyristor voltage regulator (TVR), established a model of TVR and the DG system using Matlab-, Simulink, formulated the voltage control strategy of TVR in DG system, and combined with access position of distributed resource (DR) in the system and the load variation, to conduct a comprehensive simulation...
There are three different structures between process level and bay level in digital substations below 35kV nowadays; they are IEC61850-9-1 standard, IEC61850-9-2 standard and small analog signal transmission standard. Accounting for the features of three kinds of structures and special requirements of non-effectively grounded system fault line detection device, the design of line detection device...
In China, the energy resources is against the productive forces development, the base of energy in the west is about 3000km away from the load centers in the east, so the transmission systems with long distance and large capacity should be established. In this paper, based on the design example of UHV (1000kV) AC transmission system, the Half Wavelength AC Transmission (HWACT) is introduced, and the...
In this paper, the nodal admittance equation is derived for analyzing the response of the transmission line under the residual voltage due to uniformly distributed charge along the line in Laplace domain. We equivalent the trapped charge to the current sources which are located at near-end and far-end when the disconnector switching is operated. Based on the Numerical Inverse Laplace Transform method,...
To realize the aim that in 2020 the carbon dioxide emissions per unit of GDP in China dropped to 40% ~ 45% of that in 2005, it's compulsory to take full advantage of the clean and renewable energy, develop distributed generation technology and realize low-carbon generation scheduling. According to the characteristics of photovoltaic and wind turbine, considering different generation cost and greenhouse...
The method, complex torque coefficient approach, which is used to analyze the sub synchronous oscillation (SSO) problems with the help of PSCAD/EMTDC are recommended. While how to achieve the complex torque coefficient approach by time-domain simulation method effectively has not been specified. With the simulation study of different systems like HVDC system, AC system with series compensation device,...
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