The distribution of the required load across all generators in power networks has given rise to methods solving the Economic Dispatch Problem (EDP). The main goal of the method is to find such a power distribution that the resulting price per unit of energy is minimal. Due to dynamic changes in the structure of the energy network is there currently a shift away from centralized management towards decentralized methods. In this paper, a gradient-based distributed algorithm is introduced. In proposed framework, models for Battery Energy Storage System (BESS) and variable fuel price are used. The BESS model allows energy to be stored or fed back into the grid, which can affect the final price per unit of energy. Dynamical behaviour of BESS effects final price per energy of generator units. This is equally related to the price of fuel, which can represent a change in the price of energy from the given source - the power plant. The described algorithm is subsequently validated on three examples.

This article describes a process for modern verification of safety-related I&C (Instrumentation and Control) systems based on algorithm model checking, model-based test case generation and automatic testing. The verification process is compatible with IEC 60880 standard, and utilises methods presented in previously published articles including automatic formalisation and model checking of FBD algorithms and model-based test case generation. This verification process was applied on a real safety-related I&C system for a nuclear power plant. Due to confidentiality of the real application, the process is presented mostly on an simplified example. Nevertheless, the presented results contain information about both the example model and the real safety-related I&C system. These results are utilised for discussion about suitability and efficiency of the presented verification process.

Growing complexity of power network infrastructure is increasing the demand for optimal power load distribution that provides minimal operational costs. Problem of power load distribution is solvable by Economic Dispatch Problem (EDP) methods that are applicable in various forms. To secure flexibility of changes in load distribution, it is desirable to seek a decentralized solution. This article focuses on a introduction to power network systems and extending the algorithm of gradient methods for solving EDP in a distributed way that is covered in article [1]. Specifically, it is a time-varying value of traffic delay, representation of drop-off packets, noisy calculation of the gradient and the inclusion of line losses. The fundamental idea of the algorithm from [1] is described here so that the reader does not have to study this article first.

This paper describes the design of a robust PI controller by considering several design criteria simultaneously (multi-objective optimization). Firstly, all controllers satisfying multiple frequency domain criteria (e.g. sensitivity function limits) are found in PI parameter plane using robustness regions method. Then, all suitable controllers are evaluated by the selected time-domain criterion, for example: Integral Error (IE), Integral of Time-weighted Absolute Error (ITAE) etc. Further, application of H2and H∞norms is shown in that context. The whole design toolchain is supported by advanced Matlab GUI which was used in the illustrative example. The described approach can be extended for PID controllers as well, for development of advanced autotuners and for teaching and training purposes.

Any Instrumentation and Control (I&C) system has to be properly tested to minimize the risk of faults in the system. This is even more crucial if the I&C system implements a safety function. The function of the I&C is often designed in a form of Function Block Diagram (FBD). The presented approach describes a new analytic method for automatic generation of test cases for FBD models. The test cases are generated in order to verify that the implementation behaves as intended. The test cases are designed to be used for gray-box testing of the implemented model. The automatic generation of test cases is generally faster and less prone to miss out an unsafe scenario than manual design.

Model Checking represents a mathematical method of formal verification which can prove that model satisfies its specified requirements. This article describes an approach that utilizes Function Block Diagram (FBD) models. The key benefit of this approach is the automatic transformation of the original model into a formal model which can be checked by Model Checking. In this way Model Checking can be easier integrated in the standard development process. The presented approach was developed together with the new verification process. This process can be used for the verification of safety-critical systems.

This paper deals with recent optimization trends of model-based software development in automotive industry. Over the past years, there has been a growing interest in software development optimization due to increasing amount and complexity of code, higher safety requirements, and increasing efficiency demands. Key elements of the process are identified and possible improvement is drawn based on experience during software development in ZF. One important direction of optimization is code generation directly from a model which is created in Matlab Simulink. A model transformation suitable for automatically generated code is described and possible advantages are shown in a real example.