The paper presents the dynamic model of doubly fed induction generator (DFIG) including the mechanical model, the generator model and the PWM voltage source converter model. The mechanical model uses two-mass model, a...
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A detailed user-defined (UD) reactive powercontrol (RPC) model of HVDC has been developed in powersystem Analysis Software Package (PSASP). The UD RPC model, as one part of UD HVDC models which have been set up base...
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ISBN:
(纸本)0863412467
A detailed user-defined (UD) reactive powercontrol (RPC) model of HVDC has been developed in powersystem Analysis Software Package (PSASP). The UD RPC model, as one part of UD HVDC models which have been set up based on the controlsystem of Three Gorges-Changzhou project, includes reactive power generation calculation, reactive power consumption calculation, reactive powercontrol strategies and converter reactive power regulator strategies. Each part of the UD RPC model and its guidelines are presented in this paper. Case studies are carried out on the WEPRI-7 system whose embedded HVDC models are replaced by the UD HVDC models. The simulation results show the correctness and necessity of the UD RPC model for AC/DC hybrid system interaction and stability analysis.
A method of the thyristor rapi switched capacitors is presented in this paper, which breaks through the bondage of the conventional methods. In addition, a novel algorithm of two time reactive power has been presented...
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ISBN:
(纸本)0863412467
A method of the thyristor rapi switched capacitors is presented in this paper, which breaks through the bondage of the conventional methods. In addition, a novel algorithm of two time reactive power has been presented, with which reactive power can be calculated fast. Meanwhile, with microcomputer synchronous phase lock technology, quick switching without transition can be realized, dynamic reactive compensation for impact load can be achieved, and the total response time is shorter than 16 ms. This technology not only can compensate reactive current dynamically but also can improve the voltage waveform to a certain extent. In the end, the type test waveforms and the users' field test waveforms are given to show the validity and effectiveness of this technology. This method is an effective way to improve power quality.
UPQC (unified power quality conditioner), which assembles a series voltage compensator;a shunt current compensator and an energy storage device, is the emerging device of custom power. Multiple power quality regulatio...
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ISBN:
(纸本)0863412467
UPQC (unified power quality conditioner), which assembles a series voltage compensator;a shunt current compensator and an energy storage device, is the emerging device of custom power. Multiple power quality regulation functions are implemented in UPQC simultaneously. Synthetic compensating functions of UPQC are explained systematically, and a typical topological circuit of UPQC is proposed. For further improvement of the performance of UPQC, APFC (active power factor correction) is introduced to the DC capacitive voltage control for storage unit of UPQC;moreover its working principle is expounded in detail, simulation results are presented to testify the validity of this approach. It is feasible to apply APFC to the storage unit of UPQC, which makes the performance excellent.
The research on the methodologies and implementation strategies in bulk powersystem restoration after a partial or complete collapse is of great significance. This paper provides the survey on the recent developments...
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ISBN:
(纸本)0863412467
The research on the methodologies and implementation strategies in bulk powersystem restoration after a partial or complete collapse is of great significance. This paper provides the survey on the recent developments of restoration methodologies and implementation strategies. And many new ways to form a powersystem restoration plan and how to deal with the sub-problems encountered during the restoration process are summarized and introduced. Also, the future work are presented, such as, how to consider the AC/DC hybrid system in the restoration process, how to utilize the distributed generation (DG) and how to use the wide-area measurement system (WAMS) for restoration.
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
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
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.
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
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