The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Available Transfer Capability (ATC) is an operating index that plays an important role in guiding intra-area electricity trade for interconnected systems. Continuation power flow (CPF) is the main calculation approach used to determine ATC. But in the conventional CPF method, a specific proportional linear nodal power injection mode is widely adopted, accordingly, ATC achieved by this kind of the...
The estimation of operating reserve to guarantee the system security and economic operation is an important task in power system operation. With the rapid increase of wind power installation and its large scale integration into power systems, the uncertainty of wind power should be considered in operating reserve estimation. This paper discusses the risk from wind power forecast error and introduces...
Dynamic economic dispatch (DED) is a high-dimensional, non-convex, multi-constrained optimization problem. With the increase of wind power penetration into power systems, the DED problem becomes more difficult. In the mathematical model, the constraints of wind farm output and spinning reserve are proposed to deal with the random and unpredictable nature of wind power. In the power system with large-scale...
Voltage Source Converter (VSC) based High Voltage Direct Current (VSC-HVDC) transmission technology is a novel transmission technology on the basis of pulse width modulation (PWM) technology and fully-controlled power electronics devices. The output performance of VSC mainly depends on its modulation algorithm. A new kind of SVPWM algorithm based on 60° coordinate system for three-level VSC is introduced...
As an important component of distribution network, micro-grid is the necessarily development trend for future. Micro-grid has greatly improved the random problems of distributed generation (DG). However, DGs, the power electronic equipments inevitably bring about power quality problems, especially voltage flicker and harmonics. This paper tries to study the operating regulations of micro-grid in order...
Available Transfer Capability (ATC) is a measure of the transfer capability remaining in the physical transmission network for further commercial activity over and above already committed uses. Putting forward against the defect that the traditional contingency selection method uses single index to enumerate states or disturbances, this paper introduces the active power behavior index and the voltage-reactive...
With the increasing expansion of AC/DC transmission system scale, the research on Available Transfer Capability (ATC) for AC/DC transmission systems has important academic and practical significances to AC/DC transmission system planning, operation and reliability evaluation. Most of the existing ATC calculation methods are mainly based on deterministic techniques and suitable for AC transmission...
The paper describes the use of multi-terminal HVDC transmission system based on voltage source converter (VSC) (VSC-MTDC) for connecting doubly fed induction generator (DFIG) based wind farms over long distance. The operation principles between DFIG and VSC-MTDC of the proposed system are described. Stator flux oriented vector control technology is used to execute AC excitation for DFIG rotor, then...
With the deepening reform to power industries, power systems are going to gradually open the demand side and the power consumers have to face the changes of their role in the market, and make a preliminary long-term forecasting for the electricity prices. In order to consider the relations between the spot market and the long-term contract market, this paper builds a multi-electricity price grey model...
A new method of power quality synthetic evaluation based on relative intensity entropy and local variable weight is presented in the paper. This method firstly uses the relative intensity entropy theory to extract the weights of the individual power quality indicators, and then does synthetic evaluation to the power quality data combined with the method of local state variable weight to amend the...
VSC-HVDC is the ideal transmission technology for the connection of the wind farms to the power system. In this paper the topology of VSC-HVDC for connection of wind farm was presented. Control strategy of VSC-HVDC for wind farm using DFIG was proposed. DFIG and VSC-HVDC were modeled in PSCAD/EMTDC software and simulation analysis was carried out. Simulation results were presented to illustrate the...
The issue of power quality in the distribution system is always in sense of the concern. With the high penetration of distributed generation (DG) currently, it tends to be more complicated. This paper presents a new approach to evaluate impacts of the DG on power quality of the distribution network. In the process an objective function will be modeled, which will be solved by the optimization toolbox,...
Wind power forecasting has great significance to the connection of wind farms to the electric power system. This paper analyzes individual forecast models, such as the time series forecasting, Elman network forecasting that based on the chaos theory, grey neural network forecasting, and generalized regression neural network forecasting, etc., then puts forward an entropy weight combination prediction...
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...
Available transfer capability (ATC) is defined as a measure of the system's capability for transfers of power for further commercial activity, over and above already committed uses. In practical power markets, ATC can provide important information for transmission customers, system operators and power marketers. The assessment of ATC should be carried out to assure the secure, economic, stable and...
In practical power markets, Available Transfer Capability (ATC) is crucial for transmission customers, system operators and power marketers to make a good choice. It is an indication of the expected transfer capability remaining on the transmission network. In order to assure the secure, economic, stable and reliable operation of power systems, the assessment of ATC should be carried out instantly...
Distributed generation (DG) that uses renewable energy sources has an unstable output and this can negatively affect existing electric power systems. In order to reduce above impact, we need to develop an energy control system to control the output through individual DG installed in a micro-grid. First, this paper designs a grid-connected Photovoltaic (PV) system and introduces the operation principle...
Distributed generation (DG) technology has drawn increasing attention for its tremendous benefits to customers, utilities and the environment. Furthermore, microturbine based power generation has become the most promising DG for its excellent record of improving system stability and economy. In this paper we develop a complete mathematic model, which includes the microturbine, a permanent magnet synchronous...
With the expansion of the power systems, DC power transmission has been increasingly applied in interconnection of grids. The determination of Available Transfer Capability (ATC) for the AC/DC transmission systems is significant to the system planning and operation. So far, most studies have been focused on ATC determination for AC transmission systems, few are on the AC/DC system ATC determination...
In this paper, variable weight theory and set pair analysis (SPA) theory are applied to comprehensive evaluation of power quality. Among existing comprehensive evaluation methods of power quality, the problems about index uncertainty and imbalance case are less considered. The application of variable weight SPA, for ensuring identical discrepancy contrary (IDC) of unsure system, effectively reduces...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.