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1.
With the creation of balancing authorities by the North American Reliability Council that span large portions of the North American interconnection, and stringent requirements for real time monitoring of power system evolution, faster and more accurate state estimation algorithms that can efficiently handle systems of very large sizes are needed in the present environment. This paper presents a distributed state estimation algorithm suitable for large-scale power systems. Synchronized phasor measurements are applied to aggregate the voltage phase angles of each decomposed subsystem in the distributed state estimation solution. The aggregated state estimation solution is obtained from the distributed solution using a sensitivity analysis based update at chosen boundary buses. Placement of synchronized phasor measurements in the decomposed subsystems is also investigated in this paper. Test results on the IEEE 118-bus test bed are provided 相似文献
2.
Heinrich Heydt Philipp Eisenbarth Karin Feith Klaus Urgast Gerhard Maas Manfred Regitz 《Israel journal of chemistry》1986,27(1):96-104
Amino-substituted cyclopropenylium salts ( 11a,b ) react with diazomethyl compounds ( 12a-i ) in dichloromethane or acetonitrile in the presence of a base (ethyldiisopropylamine, 1,5-diazabicyclo[4.3.0] non-5-ene) to form 4-aminopyridazines ( 13a-i ) specifically. The reaction is interpreted in terms of an initial electrophilic diazoalkane substitution to give diazomethylcyclopropenes ( 11 + 12 → 14 ) which undergo a [1.5]-cyclisation to form the betaines 16 which, in turn, isomerise with opening of the bridging bond to give the aminopyridazines 13 . In a similar manner, the tris[amino] cyclopropenylium salts 8a,b and 10a-c are converted to the 3,4,5-tris[amino]-pyridazines ( 21a-k ) by treatment with diazomethyl compounds ( 12a, c-f ). 相似文献
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The periodic steady state of power distribution system loads is studied for electronically switched, time varying cases. Many loads of this type appear on contemporary power systems as energy saving and controllable demands. Several alternative methods of calculating the periodic steady state are discussed and a new method is proposed based on the frequency modulation property of the discrete Fourier transform. The new method is termed the gain-shift formula (GSF) because the format of the technique entails adding frequency shifted terms which represent the parameter to be calculated. An example of a triac-switched load on the distribution system is given. The main advantages of the GSF are: rapid calculation of the periodic steady state; and efficient calculation of the frequency spectrum of voltages and currents in the periodic steady state 相似文献
5.
Hans-Joachim Nees Harald Keller Thomas Facklam Albert Herrmann Jochen Welsch Uwe Bergstrßer Heinrich Heydt Manfred Regitz 《Advanced Synthesis \u0026amp; Catalysis》1993,335(7):589-598
Diazo Compounds. 72. Diazoalkylphosphanes – Synthesis by Electrophilic Diazoalkane Substitution and Oxidative Addition Reactions at Phosphorus Electrophilic diazoalkane substitution of the diazomethyl compounds 1a,b with the chloro phosphanes 2a-o in the presence of lithium diethylamide yields the diazoalkyl phosphanes 3a-z . Oxidative addition of oxygen, sulfur and selenium at phosphorus leads into the series of oxo, thioxo and selenoxo phosphanes having diazoalkyl substituents ( 4a-d, 5a-m and 7a-d ). The silyl group of 5n,o is cleaved by chromatography on aluminium oxide to yield the (diazomethyl)phosphane sulfides 6a,b . 相似文献
6.
Power systems are stochastic in nature due to uncertainty in bus loading and transmission system asset status. The available transfer capability (ATC) is a measure of "available capacity" in a power transmission system beyond already committed uses, i.e., beyond base case loading. To render the ATC as a more realistic measure of transmission availability, a stochastic calculation of ATC is proposed. A stochastic power flow algorithm can be used to help quantify and evaluate the uncertainty of the ATC. The limitations considered in the stochastic ATC calculation algorithm are: transmission thermal rating limits; bus voltage magnitude limits; and transmission circuit outages. The stochastic-algebraic calculation of ATC is described and tested using a reduced order WECC 179 bus system 相似文献
7.
Bora Karayaka H. Keyhani A. Heydt G.T. Agrawal B.L. Selin D.A. 《Energy Conversion, IEEE Transaction on》2001,16(4):305-311
A novel technique to estimate and model rotor-body parameters of a large steam turbine-generator from real time disturbance data is presented. For each set of disturbance data collected at different operating conditions, the rotor body parameters of the generator are estimated using an output error method (OEM). Artificial neural network (ANN) based estimators are later used to model the nonlinearities in the estimated parameters based on the generator operating conditions. The developed ANN models are then validated with measurements not used in the training procedure. The performance of estimated parameters is also validated with extensive simulations and compared against the manufacturer values 相似文献
8.
Power system alarms are used as advice to system operators relating to problematic operating conditions. In this paper, conventional alarms and alarm processing as well as the electrical signals that produce those alarms are revisited with a view of incorporating signals that relate to marketing of electrical energy (e.g., locational marginal prices, and forward market positions). The augmented alarms, termed "economic alarms" are intended to be public information, distributed to all power market players. The issues of divulging system information publicly are discussed. An illustrative example of the concept is presented. 相似文献
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Karayaka H.B. Keyhani A. Agrawal B.L. Selin D.A. Heydt G.T. 《Energy Conversion, IEEE Transaction on》2000,15(2):181-187
This paper presents a step by step identification procedure of armature, field and saturated parameters of a large steam turbine-generator from real time operating data. First, data from a small excitation disturbance is utilized to estimate armature circuit parameters of the machine. Subsequently, for each set of steady state operating data, saturable mutual inductances Lads and Laqs are estimated. The recursive maximum likelihood estimation technique is employed for identification in these first two stages. An artificial neural network (ANN) based estimator is used to model these saturated inductances based on the generator operating conditions. Finally, using the estimates of the armature circuit parameters, the field winding and some damper winding parameters are estimated using an output error method (OEM) of estimation. The developed models are validated with measurements not used in the training of ANN and with large disturbance responses 相似文献