Reliability Evaluation Of Transmission Systems Considering Uncertainty

The reliability evaluation of transmission systems is an important part of power systems reliability evaluation. The general reliability evaluation of transmission systems ignores the uncertainty of reliability parameters and load and uses average value and maximal value to evaluate reliability respectively, which must lead to the inaccuracy of evaluation. So the uncertain information processing in reliability evaluation of transmission systems are researched. The paper includes the following respects. First of all, the significance and the current situation of reliability evaluation and the reliability evaluation considering uncertainty are introduced. The paper expatiates also the general reliability evaluation of transmission systems. Secondly, the connection number theory is applied to deal with the uncertainties of reliability parameters and a model based on connection number theory is established. The model uses connection number to express reliability parameters with uncertainties and calculates reliability indices in the form of connection number by the operation. Then, the blind number theory is used to handle synchronously the uncertainties of reliability parameters and load and a model based on blind number theory is established. The model expresses reliability parameters and load with uncertainties by the blind number and obtains reliability indices by the operation of blind number and the measures overcoming the rapid increase in blind number operation. Finally, aiming at the advantage and the disadvantage of connection number theory and blind number theory handling uncertain information in reliability evaluation, a method based on connection number and blind number is proposed. The method uses connection number to deal with uncertainties of reliability parameters and employ blind number to handle uncertainties of load. The model not only possesses synchronously the advantages of connection number theory and blind number theory, but also overcomes the disadvantages of the two theory handling uncertain information in the process of reliability evaluation. Analyzing examples shows the feasibility and effectiveness of the above approach.