International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

This paper presents a formal and practical approach onto the short-term evaluation of the impact of the different RES power generation technologies. All these are considered stochastic and basically unreliable in the active power balance but they also seem to be an irreplaceable part of the electric power generation in the future. Here a generalized hydro-thermal coordination optimization model is presented aiming to help a day-ahead power balance impacts analysis and some further risk assessment to the EPS security and resilience.

In this paper a model for optimal hydro-thermal coordination of a power system is proposed when contracts for power import and export power are available. The power flows outside the localized area of the local power system are divided into planned and planned quantities in order to assign different penalties for them in the cost criterion. The model also introduces the work of thermal and hydro power plants by separating each unit with a linear approximation. The resulting model is a mixed-integer linear programming problem.

Every optimization problem needs its appropriate model. An administrative process is specific but it also requires optimization. In this paper a practical review on the preceding stage of process decomposition is made. A review on possible approaches to the further modeling of an administrative process as an event-oriented process deriving from project management practitioners is done. The problem of decisions making under risk and uncertainty conditions is explained in the case of a discrete-event administrative process model and two approaches for uncertainty presentation are proposed for review.

In this paper we try to build a framework in optimization model building for students without previous mathematical optimization training and experience. While modeling is a matter of art, approach and compromise between complexity and closeness to reality we need to spend some time on the basics of optimization modeling such as cost function, constraints, variables and coefficients. There is a huge variety of optimization problems solved in Electric Power Systems. The most complex of all is considered to be the Unit Commitment problem where at each iteration an Economic Dispatch is performed.

In this paper a general structure of an administrative process development is proposed. A block diagram showing the logical dependencies in the development is also given and analyzed as well as the basic structures for the variants to implement the core element "task" in a an administrative processing. A concept for generalization in some of the administrative process stages is given as well as an approach to the most commonly executed internal procedure that is the approval one.

In this paper we try to build a framework in active power optimization model building when controllable loads are available for balancing purposes. A certain classification of non-fixed loads is given as well as the respective variables and constraints that have to be introduced in the mixed-integer linear programming model. A numerical example is also given illustrating the modeling approach. Some analysis on the presented numerical data is done in order to show sensitivity to certain environmental issues.

In this paper we try to bring a modeling framework in optimization problems for hydro-thermal coordination problems solved in electric power systems. There are certain specifics when dealing with hydro power plants and the reservoirs they are fed from. In many cases these water reservoirs are connected and this involves additional complications in optimization models building. We give guidelines for model size reduction and awareness. This framework is suitable for practitioners willing to be aware of hydro-power modeling and optimization but having no previous mathematical optimization training and experience.

The state administration is a part of every government and it is responsible for the implementation of certain administrative, legal and regulatory functions. An effective functioning of the state administration eases the functioning of the citizens and the business and therefore the processing in it is approached as a business process. There are certain similarities and respective differences between a business and an administrative process. In this paper an introduction into the problem is made.