Your browser does not support JavaScript!
http://iet.metastore.ingenta.com
1887

IEE Proceedings C (Generation, Transmission and Distribution)

Volume 138, Issue 1, January 1991

Volumes & issues:

Volume 138, Issue 1

January 1991

Application of pattern recognition techniques for online security-economy and reactive control of power systems
  • Author(s): C.S. Chang
  • Source: IEE Proceedings C (Generation, Transmission and Distribution), Volume 138, Issue 1, p. 1 –10
  • DOI:  10.1049/ip-c.1991.0001
  • Type: Article
  • + Show details - Hide details
  • p. 1 –10 (10)
    The paper discusses a new methodology for applying the pattern recognition method developed by the author in the two related areas of security-economy preventive control and reactive control. The work here has taken advantage of the fact that each application of the above controls would, in one way or another, vary the amount of active and/or reactive (P-Q) power injected into the network busbars, and the network would then respond by readjusting its busbar voltages and flows accordingly. Using the amount of P-Q busbar injections for evaluating the relative merits of one control measure against the others, a ‘raise’ and a ‘lower’ priority list may be formed for correcting overload on each transmission line and for correcting undervoltage at each busbar. These priority lists provide the operators with a fast, easy to use computational tool for searching the best available control measures after each contingency, and for enabling the consequence of each chosen control measures to be predicted. The paper also describes the development and results of an algorithm formulated using the linear programming technique to shift busbar P-Q injections for relieving the overloaded transmission lines, and for minimising the busbar P-Q injection change during shifting.
    Add to favourites
    Export citations
Application of power system stabilisers in a plant with identical units
  • Author(s): C.S. de Araújo  and  J.C. de Castro
  • Source: IEE Proceedings C (Generation, Transmission and Distribution), Volume 138, Issue 1, p. 11 –18
  • DOI:  10.1049/ip-c.1991.0002
  • Type: Article
  • + Show details - Hide details
  • p. 11 –18 (8)
    A new modal technique to analyse the effects of a signal to be fed back by stabilisers in a plant with identical units is proposed. The contribution of a mode on an output signal is used as a measure of the coupling input-mode-output to verify the effectiveness of the signal. The effects of stabilisers on oscillation modes are then analysed. Attention is then paid to selective control of modes. It was concluded that not only a sum of speeds, but many other signals may be used for cancellation of the contribution of intraplant modes on system response. With this cancellation, stabilisers may be applied on a plant without deteriorating the damping of these modes.
    Add to favourites
    Export citations
Method of equal probability overvoltages for calculating risk of failure of power transmission lines
  • Author(s): M.R. Gavric
  • Source: IEE Proceedings C (Generation, Transmission and Distribution), Volume 138, Issue 1, p. 19 –26
  • DOI:  10.1049/ip-c.1991.0003
  • Type: Article
  • + Show details - Hide details
  • p. 19 –26 (8)
    The paper presents a generalised numerical method for calculating the risk of failure of power transmission lines due to switching overvoltages. Contrary to other known methods, the method incorporates the influence of overvoltage profile and differences in breakdown properties of insulation along the line on the risk of failure, irrespective of their probability distribution laws. Using a special program, developed on the basis of this method, the risk is calculated for several overvoltage probability distribution laws and line insulation levels. The influence of the overvoltage distribution along the line, i.e. overvoltage profile, on the risk of failure is considered for overvoltages obtained by calculations, as well as for overvoltages obtained by measurements on a specific transmission line. If the breakdown properties of insulation are given as a function of the wave front duration, it is possible by this method to incorporate into the calculations the influence of the wave front duration along the line on the risk of failure.
    Add to favourites
    Export citations
Decomposition approach for minimising real power losses in power systems
  • Author(s): N.I. Deeb  and  S.M. Shahidehpour
  • Source: IEE Proceedings C (Generation, Transmission and Distribution), Volume 138, Issue 1, p. 27 –38
  • DOI:  10.1049/ip-c.1991.0004
  • Type: Article
  • + Show details - Hide details
  • p. 27 –38 (12)
    An efficient method for minimising real power losses and improving the voltage profile of large scale power systems is presented. The problem is solved through optimal adjustments of reactive power generation in the system by changing generator voltages, shunt capacitors, and tap setting of tap changing transformers. It is formulated in a linearised form suitable for the linear programming technique and decomposition methods. The power system planning and corresponding problems with the addition of new reactive power sources have been integrated with the operational characteristic of the system, and results have been presented. The proposed method does not require the inversion of the Jacobian matrix, and its superiority lies in the reduction of the computation time and memory space, as well as a fast convergence for the solution of large scale systems.
    Add to favourites
    Export citations
Power generation scheduling through use of generalised network flow programming
  • Author(s): R.E. Rice ; W.M. Grady ; W.G. Lesso ; A.H. Noyola ; M.E. Connolly
  • Source: IEE Proceedings C (Generation, Transmission and Distribution), Volume 138, Issue 1, p. 39 –46
  • DOI:  10.1049/ip-c.1991.0005
  • Type: Article
  • + Show details - Hide details
  • p. 39 –46 (8)
    The economic dispatch problem is important in both power system planning and operation. Although there have been major advances in defining and solving more complete optimal power flow (OPF) problems, there exists a need for constrained economic dispatch (CED) techniques which, though not as rigorous or as exact as an OPF, are fast enough to be used on desktop computers. The authors present a CED formulation that is based upon generalised network flow programming (GNFP). The methodology for applying GNFP to the CED problem is developed and illustrated in this paper using four examples: 5, 39, 264, and 515-bus systems. Starting with a solved loadflow case, execution times for the CED are shown to be about the same as for a Newton-Raphson loadflow, and memory requirements are approximately 75% of the loadflow. Salient features of the CED-GNFP method include the ability to minimise generation cost while meeting constraints on line flows and area interchange. Network location of loads and generators is automatically considered without need of penalty factors, and transmission line flow limits do not affect solution times significantly. The authors believe that, owing to its simplicity of application, robustness, and ease of implementation on desktop computers, the CED-GNFP procedure is an important adjunct to the group of techniques and algorithms currently available for solving the overall economic dispatch/OPF problem.
    Add to favourites
    Export citations
Studies on asynchronous operation of synchronous machines and related shaft torsional stresses
24-pulse HVDC conversion
Approach to automatic contingency selection by reactive type performance index
  • Author(s): J.Z. Zhu  and  G.Y. Xu
  • Source: IEE Proceedings C (Generation, Transmission and Distribution), Volume 138, Issue 1, p. 65 –68
  • DOI:  10.1049/ip-c.1991.0008
  • Type: Article
  • + Show details - Hide details
  • p. 65 –68 (4)
    The paper represents a novel approach to studying the automatic contingency selection (ACS). The total curtailment of the reactive loads is used as the performance index to evaluate the severity of contingencies. The minimum cost network flow model is proposed to determine the optimal curtailment in the line outage case. The objective of the model is the determination of the sum of branch voltage drops in terms of the line reactive flows. The optimisation model is solved by the ‘out-of-kilter algorithm’. The numerical results for several IEEE sample systems show that the proposed technique is feasible and effective.
    Add to favourites
    Export citations
Optimal design of electricity distribution networks
  • Author(s): A.C. Marshall ; T.B. Boffey ; J.R. Green ; H. Hague
  • Source: IEE Proceedings C (Generation, Transmission and Distribution), Volume 138, Issue 1, p. 69 –77
  • DOI:  10.1049/ip-c.1991.0009
  • Type: Article
  • + Show details - Hide details
  • p. 69 –77 (9)
    The interactive system, NETOPT, may be used to design subtransmission networks, principally at the 33 kV level, adopting an interconnected design philosophy advocated by MANWEB. All secure networks that are designed are stored and can, at any time, be displayed graphically and analysed by a load flow program. A relatively inexpensive, deterministic design process based on Lagrangean relaxation is employed. The cost structure used is completely new. The problem of security specification is overcome by the use of: an existing, statistically derived, security function; a ‘constraint generation’ scheme which adds missing constraints to the problem formulation when required; a collection of other new security assessing procedures. A series of cost cutting features have been added to the reformulated problem to minimise the solution time. Larger problems can be solved using either an interactive or automatic branch and bound scheme.
    Add to favourites
    Export citations
Direct solution of distribution systems
  • Author(s): S.K. Goswami  and  S.K. Basu
  • Source: IEE Proceedings C (Generation, Transmission and Distribution), Volume 138, Issue 1, p. 78 –88
  • DOI:  10.1049/ip-c.1991.0010
  • Type: Article
  • + Show details - Hide details
  • p. 78 –88 (11)
    The paper reports on a direct power flow solution technique for radial distribution networks. The special topology of distribution networks has been fully exploited to make direct solution possible. A unique branch and node numbering scheme has been proposed to achieve storage and computational economy. Composite load characteristics can be easily modelled. The method developed has been extended for meshed and unbalanced distribution networks. In both cases, modifications required are few and the advantages obtained in balanced radial networks in respect of storage and computational requirements have been preserved. The proposed method has been successfully applied to the solution of a number of practical distribution networks.
    Add to favourites
    Export citations
Optimal switching of dynamic braking resistor, reactor or capacitor for transient stability of power systems
Frequency and duration method for reliability evaluation of large-scale hydrothermal generating systems
  • Author(s): A.M. Leite da Silva ; A.C.G. Melo ; S.H.F. Cunha
  • Source: IEE Proceedings C (Generation, Transmission and Distribution), Volume 138, Issue 1, p. 94 –102
  • DOI:  10.1049/ip-c.1991.0012
  • Type: Article
  • + Show details - Hide details
  • p. 94 –102 (9)
    The paper presents a general frequency and duration (F&D) method that is especially adequate for predominantly hydro generating systems. The method is based on the property that not only the probabilities of the reserve states can be evaluated recursively by discrete convolution, but also their frequencies. Therefore, appropriate truncation and rounding techniques can be introduced allowing an efficient computation of frequency and duration indices for large-scale generating systems. The performance of the proposed F&D algorithm is analysed with two test systems. The IEEE Reliability Test System is used to measure the impact of the truncation and rounding techniques. The characteristic behaviour of frequency and duration indices in hydro systems is illustrated by a case study with the Brazilian South/Southeastern generating system.
    Add to favourites
    Export citations
Small rating capacitive energy storage for dynamic performance improvement of automatic generation control
  • Author(s): S.C. Tripathy ; R. Balasubramanian ; P.S. Chandramohanan Nair
  • Source: IEE Proceedings C (Generation, Transmission and Distribution), Volume 138, Issue 1, p. 103 –111
  • DOI:  10.1049/ip-c.1991.0013
  • Type: Article
  • + Show details - Hide details
  • p. 103 –111 (9)
    A new scheme using a small rating capacitive energy storage (CES) unit for the improvement of the dynamic performance of a power system is proposed. A comprehensive digital computer model of a two-area interconnected power system including governor dead-band non-linearity, steam reheat constraints and boiler dynamics is developed. Time domain simulations are used to study the performance of the power system and control logic. Optimisation of gain parameters and stability studies are carried out by the second method of Lyapunov. Suitable methods for control of the CES units are described.
    Add to favourites
    Export citations

Most viewed content for this Journal

Article
content/journals/ip-c
Journal
5
Loading

Most cited content for this Journal

We currently have no most cited data available for this content.

Print this page
This is a required field
Please enter a valid email address