摘要:

The real-time operation of power systems requires security assessment and enhancement computations to ensure that the system stays in the normal state for as long as possible. The paper describes an interactive computer package with colour graphics for power-system operational studies. The package includes load flows, fault analysis and security enhancement. A decoupled algorithm is used for security enhancement, and offers the operator a choice of feasible corrective actions to alleviate line overloads. These corrective actions include generator rescheduling, network voltage adjustments, switching of reactive compensation and the control of phase shifters. Experiments on three test systems are summarised and discussed

DOI:10.1049/ip-c.1983.0010

出版商:IEE    

年代:1983

数据来源: IET

摘要:

The paper presents a coherency-based identifying method of the optimum site for power-system stabilisers. After decomposing a multimachine power system into several coherent groups, the most effective selection of a generator to be equipped with a stabiliser in each coherent group is determined. The coherency recognition is made by using a coherency index in the frequency domain. Through the numerical analysis indicated in the paper, a simple and effective method for determining the best locations of stabilisers is proposed

DOI:10.1049/ip-c.1983.0011

出版商:IEE    

年代:1983

数据来源: IET

摘要:

The paper presents a comparison between analytically rigorous and simplified methods in the calculation of a transient due to the initiation of a fault at any point on an overhead line connected to a crossbonded-cable line. In the simplified method, a supposed conductive medium surrounding cable insulation layer, the magnetic shielding effect of which is approximately equivalent to that of the actual cross-bonded-cable sheath circuit and earth, is introduced. By applying the simplified method, a 7-conductor inhomogeneous system of a single circuit of actual crossbonded-cable line including the earth has been reduced to a 4-conductor homogeneous system. A simple double-ended system has been modelled, in which transmission line is accurately represented. A 275kV line is considered, and the fault transient at various locations of protective relay along the line is evaluated for both rigorous and simplified analytical models. It has been proved that the simplified method takes the computing time down one place with practically sufficient accuracy

DOI:10.1049/ip-c.1983.0012

出版商:IEE    

年代:1983

数据来源: IET

摘要:

A general method for predicting the long-line radio-noise field from measurements made on short multiconductor test line is presented. The method uses the measured values of the corona current and magnetic field, and the computed transform operators. These operators are obtained by means of an algorithm, based on the lattice technique, which takes account of the radio-frequency corona current propagation on short multiconductor lines having any terminal impedance. The transform operators may be used, even if the actual line and the test line have different geometric configurations. These operators were computed in the past by means of methods based on modal analysis, which may be used only if the terminal impedances of the short test line do not give rise to the intermode coupling: generally, this condition is not satisfied in conducted measurements of corona current. The paper also presents an algorithm for the computation of the radio-interference voltages, which wifi be used in a further study concerning the prediction of the corona noise in power-line carrier channels. The prediction method was applied to the analysis of the radio- noise field generated by the Enel's 1000 kV multiconductor test line at Suvereto, by using experimental data already known. A parameter sensitivity analysis of the transform operators was carried out with the aim of suggesting the optimal procedure for making the experimental tests. The results obtained demonstrated the convenience of using the values of measured corona currents in the transform formulas. To effect the measurements, it is preferable to have configuration with nonenergised conductors earthed at the supply end and all three conductors open at the other extremity

DOI:10.1049/ip-c.1983.0013

出版商:IEE    

年代:1983

数据来源: IET