SYSTEM OF CONTROL OF OPERATING MODES OF ELECTRIC TRACTION NETWORKS ON THE BASIS OF FUZZY DESCRIPTION OF THEIR CONDITION

Given the need to save energy and reduce the cost of passenger transport on urban electric transport, the greatest effect (from 5 to 15%) is achieved through the introduction of comprehensive information technologies based on rational modes of traction of electric rolling stock and traction and external power supply. The criterion for assessing the modes of operation of power supply systems of urban electric transport is the energy consumption of traction substations, which reflects most of the influencing factors, including the inseparable relationship of traction and external power supply systems. An approach to the implementation of energy-saving technologies of traction power supply of urban electric transport is proposed, which uses fuzzy models and methods of representation for analysis and selection of controls. It is proposed to implement the control of the power supply system operation modes and the selection of modes on the basis of a vague description of their states. When forming the rules, the following parameters are set: deviation of the daily number of transported passengers on the i-th interstation zone of the two-track section, for the characterization of which the values ​​of fuzzy values ​​"lag (strong, weak, absent)" and "advance (absent, weak, strong)" deviation of daily active energy losses for the substation zone and with the values ​​"strong, absent, weak"; the difference between the daily energy consumption of the i-th substation zone, for the actual mode of operation of the power supply system and the reference mode of uniform loading of the power supply system. When constructing a control model in the form of fuzzy rules, each fuzzy characteristic is approximated by N fuzzy quantities with triangular membership functions. For the fuzzy characteristic the minimum and maximum values ​​of an interval in which there are its admissible values ​​are set. Approximate quantities have a triangular degree of belonging: the vertex lies in the center, it corresponds to the degree of belonging 1, and the other two vertices - on the sides of it with degrees of belonging 0. The fuzzy conclusion is based on the rule of fuzzy Mamdani implication. The constructed base of fuzzy rules, which replaces the model of modes of the power supply system, can be used as a guide to the energy dispatcher to select control for the next time period, taking into account the conditions of uncertainty. The principles of formation of algorithms and filling of databases and knowledge of expert systems are developed and problems of maintenance of modes of energy saving in systems of traction power supply of city electric transport are solved. The proposed algorithms for creating databases of expert systems can be implemented after the modernization of power supply control systems based on new integrated systems. Expert systems must be included in the software of the automated workplace of the energy dispatcher. Their inclusion is planned after introduction of new microprocessor systems of telemechanics of regional control points.

Homomorphism and Characterization of Lattice−Fuzzy sub Γ-Nearrings

In this article, we bring in the concept of homomorphism of an Lattice-Fuzzy sub Γ-Nearring where L is a complete lattice satisfying infinite meet distributive law. Also, we define an Lattice-Fuzzy characteristic Sub Γ-Nearring and establish a one-one correspondence between an Lattice-Fuzzy characteristic Sub Γ-Nearring of a Γ-Nearring and crisp characteristic Sub Γ-Nearring of a Γ- Nearring.

Fuzzy Logic Approach for Material Selection in Mechanical Engineering Design

The selection of materials for a product in mechanical design holds a great importance as the selection of a specific material can impact the success or failure of the product. There are lot of methods and approaches that are available for material selection process, but majority of them work well with only material properties dealing in quantitatively measured properties. With so much amount of material being developed and researched each and every day, the selection of an optimum material has become a fuzzy characteristic. In this chapter, a simplified fuzzy logic is used as a simple, easy and effective method for choosing an optimum material in mechanical design problems. An illustration is carried out when the fuzzy logic is applied to the selection of material for aircraft wing's spar and how an optimum material is achieved.