Asymmetric load is quite common in distribution network, the compensation of which is a serious problem under some situations. A novel integrated compensation method is put forward based on the principle of reactive p...
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Available transfer capability (ATC) determines the largest transfer that can be implemented in a certain direction across the power grid without violating security constraints. The uncertainties including load level, ...
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ISBN:
(纸本)0863412467
Available transfer capability (ATC) determines the largest transfer that can be implemented in a certain direction across the power grid without violating security constraints. The uncertainties including load level, aging and maintenance of elements and weather conditions, which have great influence on powersystem operation should be taking into account when calculating ATC. Considering time-varying nature and uncertainty of system parameters, the time-dependent model is adopted to describe the effects of weather conditions, aging and maintenance on element fault rates. Time-varying restoration time and load are modeled using random variables. The sequential simulation technique is applied to sample the system states, then based on linear programming and DC power flow ATC calculation is proposed. The algorithm based on MATLAB 6.5 is developed. IEEE 14-bus test system is used to verify the presented approach.
The relation between the voltage at the end of the opened phase conductor (VATEOTOPC) and the sum voltage of the two healthy phases (SVOTTHP) are analyzed. An integrated criterion based on the relation is proposed to ...
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ISBN:
(纸本)0863416381
The relation between the voltage at the end of the opened phase conductor (VATEOTOPC) and the sum voltage of the two healthy phases (SVOTTHP) are analyzed. An integrated criterion based on the relation is proposed to determine the fault nature of single-phase faults. The integrated criterion is simple in scheme and can be realized easily. It can distinguish between temporary and permanent faults effectively and has good adaptability to load currents and fault distances. Simulation tests show that the conclusions in this paper are correct.
This paper presents an approach to the detection of harmonics and reactive currents in single-phase circuit according to the orthogonal characteristic of sine function. The method is simple and practical, which cannot...
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In this paper, a novel method for perturbed trajectory prediction of post-fault rotor angle is presented based on PMU (phasor measurement unit) measurements and trigonometric function curve fitting technique. A mathem...
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ISBN:
(纸本)9780780391932
In this paper, a novel method for perturbed trajectory prediction of post-fault rotor angle is presented based on PMU (phasor measurement unit) measurements and trigonometric function curve fitting technique. A mathematical model about the relationship of post-fault rotor angle and time is derived from a speed-governing system model, which reveals that the perturbed trajectory of the post-fault rotor angle can be expressed by trigonometric functions. By curve fitting technique, a least square method to predict the perturbed trajectory using trigonometric function is proposed. Numerical simulations are conducted on IIEEE 9-bus system to test the effectiveness of this method. The proposed method can give more reasonable and more promising prediction results as compared with polynomial curve fitting technique.
With the increasing of grid-size, the problems of powersystem stability become more and more prominent. Meanwhile, it is very urgent to achieve quantitative stability analysis for the operation of electricity market....
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With the increasing of grid-size, the problems of powersystem stability become more and more prominent. Meanwhile, it is very urgent to achieve quantitative stability analysis for the operation of electricity market. The advent of WAMS (wide area measurement system) provides a new way for studying multi-swing stability of powersystem. In this paper, a curvature vector of an electric machine kinetic energy-power angle curve is defined firstly, and then the relationship between the defined curvature vector and the corresponding individual machine stability is analyzed. The validity of the relationship is proved in detail. Therefore, the curvature vector of kinetic energy-power angle curve as a new stability assessment function is proposed. A new criterion of stability assessment based on WAMS is proposed. Numerical simulations are conducted on IEEE-9 bus system and 6 machines-22 bus system of China EPRI to demonstrate the effectiveness of this criterion.
An equivalent continuous-time state-space model for VSC-HVDC in the synchronous dq reference frame has been established in the paper. Based on the model, relevant control strategies have been developed for the cases o...
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Reasonable black-start plans are necessary for restoring the powersystem quickly. Based on analytic hierarchy process (AHP) and data envelopment analysis (DEA), a novel strategy for assessing black-start plans is pro...
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ISBN:
(纸本)0863412467
Reasonable black-start plans are necessary for restoring the powersystem quickly. Based on analytic hierarchy process (AHP) and data envelopment analysis (DEA), a novel strategy for assessing black-start plans is proposed in this paper. First, the objective and requirements of restoration are analyzed thoroughly. So, assessment hierarchy is divided appropriately through employing AHP and the relative importance of assessment criteria is identified. Secondly, plans are compared with regard to different assessment criteria by means of DEA. Finally, plans are assessed comprehensively through integrating results of first two steps. The application to a practical powersystem verifies that the strategy could provide dispatchers more exact decision references.
The black start restoration of a powersystem after a complete blackout is a very important issue to safety of the powersystem. The reasonable network reconfiguration strategy is necessary for establishing the main n...
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There are many PSS and additive damping controllers of FACTS in modern powersystems. As the interaction among controllers is important to powersystem stability, the damping characteristic study of such system with m...
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ISBN:
(纸本)0863412467
There are many PSS and additive damping controllers of FACTS in modern powersystems. As the interaction among controllers is important to powersystem stability, the damping characteristic study of such system with multicontroller is necessary. In this paper the AC/DC mixed powersystem with PSS, DCM and additive damping controller of TCSC is analyzed by the signature analysis method, the damping characteristic of complex powersystem is gained and the effect of adjustable parameter of controllers on damping and the interaction among controllers are studied. The conclusions we have drawn will have important guiding significance to the coordination and stability control.
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