Molecular mechanisms of the regulation of ATPase cycle in striated muscle

New data on the molecular mechanism of the regulation of ATPase cycle by troponin-tropomyosin system have been obtained in reconstructed muscle fibers by using the polarized fluorescence technique, which allowed us following the azimuthal movements of tropomyosin, actin subdomain-1 and myosin SH1 helix motor domain during the sequential steps of ATPase cycle. We found that tropomyosin strands "rolling" on thin filament surface from periphery to center at ATPase cycle increases the amplitudes of multistep changes in special arrangement of SH1 helix and subdomain-1 at force generation states. These changes seem to convey to actin monomers and to myosin "lever arm", resulting in enhance of the effectiveness of each cross-bridge work. At high-Ca^2+^ troponin, a shift of tropomyosin strands further to center at strong-binding states increases this effect. At low-Ca^2+^ troponin "freezes" tropomyosin and actin in states typical for weak-binding states, resulting in disturbing the teamwork of actin and myosin

Intelligent Electric Power Systems with Active-Adaptive Electric Networks: Challenges for Simulation Tools

The motivation of the presented research is based on the needs for development of new methods and tools for adequate simulation of intelligent electric power systems with active-adaptive electric networks (IES) including Flexible Alternating Current Transmission System (FACTS) devices. The key requirements for the simulation were formed. The presented analysis of simulation results of IES confirms the need to use a hybrid modelling approach

Software and Hardware Complex for Setting of Automatic Excitation Regulators of Turbogenerators

The motivation of the presented research is based on the needs for development of new methods and tools for research setting problem of automatic excitation regulators of turbogenerators. Simulation tools must meet the requirements of reproduction processes reliability in all elements of electric power system. The developed block diagram of the adequate mathematical model of automatic excitation regulator is presented. The simulation results of electric power system scheme confirm the adequacy of the reproduction processes of functioning of automatic excitation regulator and a generator

Mathematical Simulation of the Transformer Differential Protection, Based on the Time-Impulse Principle

The modern electric power systems (EPS) are large, multi-parameter, stiff, non-linear and dynamic systems. Control and protection of such systems are extremely complex and urgent tasks. It is confirmed by the statistic of accidents in EPS: about 25 % of severe accidents are caused by wrong actions of relay protection (RP) and automation of EPS. The 30 % of these incorrect actions are caused by inadequate setting. The goal of this work is to solve the problem of RPs setting through the usage of detailed models that take into account specific features of the RPs and processes in transducers. The paper focused on the solution of the problem for the transformer differential protection (TDP), based on the impulse-time principle – DZT-21/DZT-23. The presented research results confirm the effectiveness of the usage of the appropriate mathematical models for the problem solution. The presented fragments are a part of a single project aimed at the problem’ solution for all the RPs devices

Mathematical Simulation of the Transformer Differential Protection, Based on the Time-Impulse Principle

The modern electric power systems (EPS) are large, multi-parameter, stiff, non-linear and dynamic systems. Control and protection of such systems are extremely complex and urgent tasks. It is confirmed by the statistic of accidents in EPS: about 25 % of severe accidents are caused by wrong actions of relay protection (RP) and automation of EPS. The 30 % of these incorrect actions are caused by inadequate setting. The goal of this work is to solve the problem of RPs setting through the usage of detailed models that take into account specific features of the RPs and processes in transducers. The paper focused on the solution of the problem for the transformer differential protection (TDP), based on the impulse-time principle – DZT-21/DZT-23. The presented research results confirm the effectiveness of the usage of the appropriate mathematical models for the problem solution. The presented fragments are a part of a single project aimed at the problem’ solution for all the RPs devices