Adaptive Neural Network Controller for Thermogenerator Angular Velocity Stabilization System

The paper presents an analytical and simulation approach for the selection of activation functions for the class of neural network controllers for ship’s thermogenerator angular velocity stabilization system. Such systems can be found in many ships. A Lyapunov-like stability analysis is performed in order to obtain a weight update law. A number of simulations were performed to find the best activation function using integral error criteria and statistical T-tests

Dizajn adaptivnog regulatora s neuronskim mrežama za regulaciju frekvencije u elektroenergetskom sustavu s toplinskim turbinama

This paper deals with analytical and simulation approach for choice of activation functions and instead of a number of nodes for a class of neural network controllers for frequency control of thermal power systems. Neural network update laws are derived via Lyapunov like stability analysis. When number of nodes is fixed, then simulation analysis is conducted to find the best performer activation function. Best performance is chosen using integral error criteria and proper statistical tests.Članak opisuje analitičko-simulacijski pristup izboru aktivacijskih funkcija i broja čvorova za klasu regulatora s neuronskim mrežama za regulaciju frekvencije u elektroenergetskom sustavu s toplinskim turbinama. Zakoni učenja neuronske mreže su izvedeni kroz analizu stabilnosti primjenom funkcije Ljapunova. Nakon što je odre.en broj čvorova, proveden je simulacijski postupak za odre.ivanje najbolje aktivacijske funkcije. Najbolja funkcija za dani regulator je odre.ena korištenjem kriterija integralne pogreške i statističkim testiranjem

Nonlinear Resonant Jump in Rudder Positioning Electrohydraulic Systems

The rudder positioning electrohydraulic system, as many other complex systems, is a nonlinear system. In nonlinear systems, a nonlinear resonant jump can occur. The paper deals with the analysis of the rudder positioning electrohydraulic system regarding the nonlinear resonant jump caused by saturation of the electrohydraulic proportional valve. The meaning of the term “resonant jump” is explained in the introduction. Then, the basics needs for occurrence of nonlinear resonant jump phenomenon are given. The rudder positioning electrohydraulic system is also described. Two methods of analyzing system with respect to resonant jumps are described: the analytical method and the simulation method. When performing the analytical analysis based on the describing function approach, the analysis of the variations of important parameters, including saturation, is performed. Then, the confi rmation of the results of analytical analysis is illustrated by the simulation method. Also, the simulation procedures, like creating an excitation signal and accelerating the simulation by using vectors in Simulink/Matlab simulation software package, are explained in detail

PRIJEDLOG OPSEGA PODATAKA ZA MONITORING PROIZVODNIH JEDINICA U PRIMARNOJ REGULACIJI FREKVENCIJE

Stabilan pogon elektroenergetskog sustava temelj je za sigurnu i pouzdanu opskrbu potrošača električnom energijom. Frekvencija, kao mjera usklađenosti između proizvodnje i potrošnje električne energije, ključan je parametar za osiguranje stabilnosti elektroenergetskog sustava. Sve proizvodne jedinice priključene na elektroenergetski sustav opremljene su sustavima za regulaciju djelatne snage i frekvencije, češće zvanima turbinski regulatori. Turbinski regulatori reagiraju na promjenu frekvencije elektroenergetskog sustava na način da reguliraju dotok pogonskog medija, pare ili vode, na turbinu agregata. Ovaj se regulacijski proces naziva primarna regulacija frekvencije. Primarna regulacija frekvencije osigurava brzu injekciju djelatne snage u elektroenergetski sustav u slučaju iznenadnog gubitka određene količine proizvodnje djelatne snage bilo gdje u elektroenergetskom sustavu, i posljedičnog pada vrijednosti frekvencije. Monitoring sudjelovanja proizvodnih jedinica u primarnoj regulaciji frekvencije unapređuje mehanizme nadzora elektroenergetskog sustava i njegovih podsustava, a samim time i povećava sigurnost pogona elektroenergetskog sustava

Modelling heat loss through multi storey double skin façade as preliminaries for an energy efficient control strategy

The paper introduces a novel strategy to improve energy consumption by applying new technical solution in Double Skin Façade (DSF) systems. The strategy is based on equalizing thermal loss through all elements of the envelope, but without direct action on interior zone. The focus of this study is in modelling as preliminary action before designing an efficient control strategy through Artificial Neural Network (ANN) based on Lyapunov-like tuning. Results of other experiments will justify the usage of this simplified differential description in further control study of DSF dynamics

Multilayer Neural Net Trajectory Tracking Control for Underwater Vehicle

An adaptive multilayer neural network controller for high precision maneuvering of underwater vehicles is presented. Maneuvering of underwater vehicles requires special attention to a number of factors, including thruster and vehicle’s nonlinearities, couplings which exist between various degrees of freedom as well as effects of the sea currents. The neuro control system for underwater vehicle maneuvering described in this paper is based on a conventional controller supported with the so-called adaptive neural network. The adaptive neural network has two tunable layers, thus the problem of selection of proper basis is avoided

Zamjena sustava turbinske regulacije proizvodne jedinice B HE Dubrovnik

U članku je predstavljena zamjena sustava turbinske regulacije proizvodne jedinice B HE Dubrovnik. U uvodu su navedeni glavni razlozi za zamjenu sustava turbinske regulacije. Nakon toga opisani su radovi i usluge potrebni za isporuku sustava po načelu ključ u ruke. Opisan je postupak projektiranja sustava. Predstavljeni su podsustavi sustava turbinske regulacije: elektrohidraulički podsustav sa hidrauličkim agregatom, hidrauličkim akumulatorima i hidrauličkim servomotorima, senzorika sustava turbinske regulacije, te ormari pomoćnih pogona i turbinske regulacije. Naznačeno je upravljanje sustavom turbinske regulacije. Navedena su tvornička, primopredajna ispitivanja i puštanje u pogon. Na kraju je dan osvrt na primopredajna ispitivanja i puštanje u pogon proizvodne jedinice B HE Dubrovnik