In this paper, a novel model of opportunity cost of spinning reserve capacity is proposed based on sequential dispatching. A model of strategic behaviors of generation firms based on conjectural variation is proposed ...
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In this paper, a novel model of opportunity cost of spinning reserve capacity is proposed based on sequential dispatching. A model of strategic behaviors of generation firms based on conjectural variation is proposed to apply in monopoly spinning reserve capacity markets with incomplete information. According to the conjectural variation model, each firm rationally maximizes its profits while considering reactions of their competitors. The advantage of this method over others is that it is a real reflection of actual power markets without the need to know all firms' actual costs. Examples are used to illustrate that the proposed model is logical and practical.
A Super Capacitor Energy Storage (SCES) system applied to distributed generation system and distribution network is presented. Application studies of the SCES system for active power supply, voltage control and harmon...
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A Super Capacitor Energy Storage (SCES) system applied to distributed generation system and distribution network is presented. Application studies of the SCES system for active power supply, voltage control and harmonic elimination are described. With inverter control, both active and reactive power pumped into the utility grid can be controlled. The proposed approach combines a dual-loop voltage and current control and a powercontrol which does not require knowledge of the equivalent impedance of the utility grid the SCES unit is connected to. Furthermore, the proposed powercontrol has superiorities as strong P and Q regulation capability, fast enough response, and purely sinusoidal line current. Finally, experiments are performed to verify the proposed theory which shows its well performances.
VSC-HVDC technology based on voltage source converter (VSC) and isolated gate bipolar transistor is a kind of novel HVDC technology for low power and long distance with flexible control and operation modes. In this pa...
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VSC-HVDC technology based on voltage source converter (VSC) and isolated gate bipolar transistor is a kind of novel HVDC technology for low power and long distance with flexible control and operation modes. In this paper, the dynamic mathematic model of VSC-HVDC with SPWM control is founded based on analyzing the fundamental principle of VSC-HVDC system. Its switch characteristic and dynamic operation mechanism are analyzed. Simulation results of dynamic operation characteristics for VSC-HVDC system with a rapid power change or a short time fault show that the theoretical analysis is correct. This is a basement to do more dynamic analysis for VSC-HVDC
This paper put forward to an interactive flexible SCADA system in which information shared, on the basis of analyzing and summarizing the defections of former SCADA. It not only solves the interaction of data and func...
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This paper put forward to an interactive flexible SCADA system in which information shared, on the basis of analyzing and summarizing the defections of former SCADA. It not only solves the interaction of data and function in the information islands, but also solves functions coordination and data exchange of distributed application system in different location. The paper proposes the concept of general data acquisition, discusses the structure and the ways of technology support, and describes the application of flexible SCADA based on the example of fault decision support system (FDSS). This proposal flexible SCADA extends and develops the data source of traditional SCADA and enriches the data foundation for powersystem advanced analysis software
Against the stability of the multi-infeed HVDC (MIDC) transmission system, voltage source converter based HVDC (VSC-HVDC) is applied to MIDC systems. The new systems can reduce probability of commutation failure and i...
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Against the stability of the multi-infeed HVDC (MIDC) transmission system, voltage source converter based HVDC (VSC-HVDC) is applied to MIDC systems. The new systems can reduce probability of commutation failure and improve the stability of the MIDC systems. A physical model of a multi-infeed HVDC and VSC-HVDC system is developed, and its mathematical model is analyzed. The rectangular coordinate form of VSC's power transmission equations is deduced through coordinate conversion. Based on the inverse system method for multivariable nonlinear control, the nonlinear controllers of the multi-infeed HVDC and VSC-HVDC system are designed. Simulation results by PSCAD/EMTDC show that the designed nonlinear controllers improve effectively the voltage stability of the multi-infeed HVDC and VSC-HVDC systemunder small or large disturbances, such as short circuit fault, reduce the probability of commutation failure in the inverter of HVDC systems and increase the operation reliability of HVDC systems
It is a trend to construct unattended substation in powersystem *** paper systematically analyses the superiority and limitation of MATLAB and Visual C++ and illustrates how to compile m-files to cpp-files by MATLAB ...
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ISBN:
(纸本)0863416381
It is a trend to construct unattended substation in powersystem *** paper systematically analyses the superiority and limitation of MATLAB and Visual C++ and illustrates how to compile m-files to cpp-files by MATLAB engines and integrate cpp-files code into existing C++ projects by Visual C++ to realize intelligent function on image recognition used for unattended *** intelligent function can effectively test illegal intrusion and fires through the detection and recognition of moving goals by three-image difference method and self-adapting threshold value segmentation algorithm and detect situations of disconnection link by use of image crop and image index processing and give warnings to alarm system. Because of lacking of brightness of image or nonlinear brightness and being influenced by kinds of noise,this paper determines to adopt contrast enhanced algorithm and high-frequency enhanced algorithm to repair grey-scale distribution and uses median filtering to remove noise of image. In the end,this paper brings forward the expectation about the image recognition of the unattended substation. When non-uniform of image illumination distribution, grey-scale of background changes largely and image segmentation has not the fittest threshold, so the paper uses self-adapting threshold segmentation algorithm to gain the image segmentation.
In this paper, a novel real time data compression and reconstruction method is proposed to process a large amount of steady state and transient data of powersystem. Based on the biorthogonality filters group with the...
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In this paper, a novel real time data compression and reconstruction method is proposed to process a large amount of steady state and transient data of powersystem. Based on the biorthogonality filters group with the linear wavelet (WT) of lifting scheme and Huffman coding approach, the new algorithm is studied and developed. The field data are used to test the method. The results prove that the method is valid with less data processing time and as high as about 9 times of compression ratio. This method is suitable for the real-time compression of mass data recorded continuously by dynamicmonitoring devices of electric powersystem
With the development of power grid interconnection, it is necessary for operators to know about systemdynamic status while disturbance occurs in powersystems in order to take appropriate counter measures to ensure t...
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With the development of power grid interconnection, it is necessary for operators to know about systemdynamic status while disturbance occurs in powersystems in order to take appropriate counter measures to ensure the powersystemsecurity. The advent of wide area measurement system (WAMS) makes the monitoring of powersystemdynamic behavior become possible. Based on WAMS, a method for identifying different kinds of disturbance in powersystem is presented in this paper. Firstly, the features of disturbances (i.e. short circuit, load shedding and loss of generation) that frequently occur in powersystem are analyzed in detail. Then, based on the idea of pattern recognition, the suggested disturbance identification method is discussed. Finally, computer simulation results are carried out in North China power grid, which demonstrate the validity of theoretical analysis and the feasibility of the proposed disturbances identification method
A practical ride through scheme bases on super capacitor energy storage system for ASD (adjustable speed drive) equipment is presented in this paper. The topology of ASD discussed adopts AC-DC-AC structure and 12 puls...
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A practical ride through scheme bases on super capacitor energy storage system for ASD (adjustable speed drive) equipment is presented in this paper. The topology of ASD discussed adopts AC-DC-AC structure and 12 pulses diode rectifier as input interface. Super capacitor (SC) module connects to inverter DC bus to support DC voltage while power quality problems such as voltage sag or short-term outage take place in power source. A SC energy storage system based 15 kVA ASD prototype was developed. Digital simulation and physical experiments were carried out to verify the correctness and validity of proposed ASD ride through topology and control strategies
A novel method for perturbed trajectory prediction of post-fault rotor angle is presented in this paper, which is based on phasor measurement unit (PMU) measurements and trigonometric function curve fitting technique....
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A novel method for perturbed trajectory prediction of post-fault rotor angle is presented in this paper, which is based on phasor measurement unit (PMU) measurements and trigonometric function curve fitting technique. A mathematical relationship of post-fault rotor angle and time is derived from a speed-governing system, which reveals that the perturbed trajectory of the post-fault rotor angle can be expressed by attenuation trigonometric functions. Using curve fitting technique and trigonometric function, a least square method to predict the perturbed trajectory is proposed. Numerical simulations are conducted in IEEE 9-bus system and the simplified north China grid to test the effectiveness of the proposed method. The proposed method can give more reasonable and more promising prediction results as compared with polynomial curve fitting technique.
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