The paper concerns the assessment of blackout hazards in the power systems. On the basis of statistical data from more than one hundred failures in power systems that affected the world in the last fifty years, the analysis was carried out regarding the number of people affected by a blackout, power losses in the system, duration of a failure and its direct causes. The paper also describes the methodology of risk analysis and vulnerability analysis of the extraordinary events occurrence in electrical power systems resulting in failures. The structure of risk analysis was based on the bow tie model, identifying threats, unwanted events, barriers and consequences of a system failure. Moreover, particular attention was drawn to the impact of the power reserve deficit in the Polish Power System in the coming years on the increase in the risk of a blackout failure.
The offshore Oil & Gas Industry is very important to the European Union economy. Therefore it must be properly monitored and protected, and legal regulations must be in place. Directive 2013/30/EU implemented on July 18, 2018 obliged EU Member States as well as operators and owners of oil and gas related activities in sea areas to implement solutions reducing the risk of major accidents, minor accidents and dangerous situations. The purpose of the article is to identify all the possible hazards that may occur during oil and gas operations in marine areas and attempt to assess the risk along with providing effective responses in the event of its occurrence by preparing appropriate plans for responding to the situation. For the completion of the main purpose of the work the provisions of Directive 2013/30/EU of the European Parliament and of the Council of 12 June 2013 on safety of offshore oil and gas operations were presented and analyzed using the Hazard Identification method, the analysis of available reports prepared by the European Commission, classification bodies and own experience obtained while working in the offshore industry during searching, drilling and oil and gas production located under the seabed at the Polish Economic Executive Zone. The study presents numerous analyses and comments, which were presented in the form of graphs and tables, based on international reports and own experience gained while working in an offshore company.
The difficulty of innovation risk assessment makes it necessary to use a multi-criteria analysis. Innovative projects are related to unstructured problems and the uncertainty, therefore, the use of fuzzy logic in the innovation risk assessment is analyzed. This paper proposes a method of determining the weights of criteria in order to innovation risk assessment. The weights are determined by 5 general criteria and 14 detailed criteria of innovation risk assessment. The proposed method is an extension of the fuzzy AHP method. The extension consists in taking into consideration the group decision-making approach with experts’ psychological conditions. The groups of experts have been chosen based on an elaborated form. The form makes it possible to characterize the persons within the scope of different psychological conditions. The proposed method provides objective and rational decision-making. The paper presents also a comparison of results with the fuzzy AHP method without the group decision making. The weights obtained by the proposed method are more diversified and bring out the most important criteria.
The article describes a shock safety modeling method for low-voltage electric devices, based on using a Bayesian network. This method allows for taking into account all possible combinations of the reliability and unreliability states for the shock protection elements under concern. The developed method allows for investigating electric shock incidents, analysing and assessing shock risks, as well as for determining criteria of dimensioning shock protection means, also with respect to reliability of the particular shock protection elements. Dependencies for determining and analysing the probability of appearance of reliability states of protection as well as an electric shock risk are presented in the article.
The article presents a shock safety model of an indirect contact with a low-voltage electric device. This model was used for computations and analyses concerning the following: the probabilities of appearance of the particular shock protection unreliability states, electric shock states (ventricular fibrillation), contributions of the unreliability of different shock protection elements to the probability of occurrence of these states, as well as the risk of electric shock (and the shock safety), and contributions of the intensity of occurrence of damages to different shock protection elements to this risk. An example of a possibility to reduce the risk of an electric shock through changing the intensity of occurrence of damages to the selected protection elements was provided.