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Summary form only given. This paper presents a screening technique for greatly reducing the computation involved in determining the optimal location of a unified power flow controller (UPFC) in a power system. The first-order sensitivities of the generation cost with respect to UPFC control parameters are derived. This technique requires running only one optimal power flow (OPF) to obtain UPFC sensitivities...
The proposed paper describes some of the most important parts of a modern security system Siguardreg (patent pending), which can be connected to control centers via standardized interfaces for the exchange of the actual state-estimator results of the power system.
The Midwest ISO performs exploratory studies to determine information about the combined generation and transmission system operating the Eastern Interconnection and the Joint and Common Market with PJM. The example in this paper is a simulation of the power system in the year 2016 with 16,000 MW of wind generation added to a MISO and PJM wide 765 kV transmission system. High Surge Impedance Loading...
Reliable operation of power system is fundamental to the on-going industry reform. This paper presents the result of marginal power flow evaluation performed on Korean power system using two commercial software packages: Physical and Operational Margins (POM V. 2.2) and probabilistic reliability assessment (PRA V. 3.1), respectively. The case study of Korea power system for year 2006 data shows that...
To improve the transient angle stability of an two- area interconnected ac/dc power system, robust controllers are suggested in this note both for excitation systems of generators and dc power modulation, based on the COI (center of inertia) dynamic information of the system. In the control strategy, the rotor angles and frequencies of all generators track the angle and frequency of the dynamic COI...
In general, a microgrid can operate in both the grid-connected mode and the islanded mode where the microgrid is interfaced to the main power system by a fast semiconductor switch called static switch, (SS). It is essential to protect a microgrid in both the grid-connected and the islanded modes of operation against all types of faults. The major issue arises in island operation with inverter-based...
Power system is a wide-area distributed system whose dynamic behavior is very complex. To analyze and control such a system, it is either too difficult to set up a particular and accurate mathematic model or the hypothetical conditions for setting up the model are difficult to be satisfied in practice. However, the human behavior, which is ball-catching theorem studied in robotics, tells us that we...
This paper studies flicker evaluation considering power quality disturbance. A flicker problem with light device irritates human's eyes. Also, the flicker problem has an influence on adverse effect such as rolling device and rotating device. However, a study of flicker evaluation is not complete. A flicker is measured and evaluated at monitoring point. We consider power quality disturbances such as...
In this paper, a new method of hybrid non-linear state estimation with PMU is proposed. Firstly, the voltage phasor measurements are transformed into indirect equivalent branch current measurements, with which the conventional state estimator takes the impact of PMU into consideration. Secondly, the indirect measurement errors caused by the measurement transforming are analyzed and calculated in detail...
Short-term load forecasting plays an increasingly important role in the electric network dispatching organization. Here, the default rules mining algorithm is applied to power system short-term load forecasting. First, the conditional attributes such as temperature and humidity that affect load characteristics are discretized by rough set discretization algorithm based on Gini index, and the consideration...
The renewable energy sources are going to become the long-term solution for future energy. Adequate infrastructure development is of crucial importance to harness power from them. This paper accumulates state-of-the-art issues and feasible solutions associated with large scale deployment of the renewable energy technologies. Various alternatives presented here are likely to change the look of the...
This paper compares performance characteristics of conventional current transformers and Rogowski coils used for protective relaying purposes. Rogowski coils have low-power outputs. They are linear (do not saturate like conventional iron- core current transformers), are compact in size, and light in weight. This paper describes current technology and application for Rogowski coils, which serve in...
The rapid growth of Chinese economy leads to fast development of electric power industry, which greatly promotes higher education on electrical engineering and the research and development (R&D) on power systems in China. In the meantime, the Ministry of Science & Technology of China (MSTC) and the National Natural Science Foundation of China (NSFC) play an important role in planning and supporting...
Taking advantages of proportional-integral-differential (PID) control in voltage regulation, and those of linear optimal control in dynamic stability, a new excitation control scheme based on fuzzy logic control is proposed. The method adjusts the weights of voltage regulation tunnel and auxiliary stabilizing tunnel on-line according to different operating conditions by a fuzzy controller, aiming...
Recent power system events have shown that voltage collapse can be a root cause of some widespread outages. The thrust of this paper is to discuss some means of mitigating system voltage depressions that are available through the scheme which utilizes both reactive current droop compensation and line drop compensation. The point that the voltage regulator controls can be acquired by a new method which...
The changed measurement triggering mode (CMTM) of state estimation (SE) is presented. Measurements from SCADA and WAMS can be handled uniformly under this mode. The sensitivity relationship among state, measurements and estimated power is analyzed and the tracking SE algorithm based on sensitivity analysis is presented. At each triggering moment, only the changed measurements are handled by this sensitivity...
Trajectory sensitivities provide a way to quantify the variation of trajectory resulting from (small) disturbances of parameters and/or initial condition. The trajectory sensitivity analysis has been applied in parameter identification, dynamic performance analysis of power system, and so on. The calculation of trajectory sensitivity is commonly based on the definition of itself. It relies on the...
Synchronized phasor measurement technology has been gaining increasingly interests in China due to its wide area time synchronization capability and fast transmission speed. Over 10 years of implementation of wide area measurement system (WAMS) in Chinese power grid have shown its great value in power system dynamic monitoring and potential applications in system modeling and validation, feedback...
As one of the most promising renewable energy sources, wind power technology has been widely developed in recent years. As increasing of penetration levels of wind power on power systems, several research fields in power systems involving system modeling, planning, control and dynamics et al., are emphasized further with the consideration of wind power. This paper reviews the wind turbine dynamic...
Nowadays, wind turbine generator (WTG) is increasingly required to provide control capabilities regarding output power. Under this scenario, this paper proposes an output power control of WTG using pitch angle control connected to small power systems. By means of the proposed method, output power control of WTG considering states of power system becomes possible, and in general both conflicting objectives...
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