Frequency Control of a Slow Oscillatory Network by a Fast Rhythmic Input: Pyloric to Gastric Mill Interactions in the Crab Stomatogastric Nervous Systema

1998 ◽  
Vol 860 (1 NEURONAL MECH) ◽  
pp. 226-238 ◽  
Author(s):  
EVE MARDER ◽  
YAIR MANOR ◽  
FARZAN NADIM ◽  
MARLENE BARTOS ◽  
MICHAEL P. NUSBAUM
2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
J. P. Dada ◽  
J. C. Chedjou ◽  
S. Domngang

We show a technique for external direct current (DC) control of the amplitudes of limit cycles both in the Phase-shift and Twin-T oscillators. We have found that amplitudes of the oscillator output voltage depend on the DC control voltage. By varying the total impedance of each oscillator oscillatory network, frequencies of oscillations are controlled using potentiometers. The main advantage of the proposed circuits is that both the amplitude and frequency of the waveforms generated can be independently controlled. Analytical, numerical, and experimental methods are used to determine the boundaries of the states of the oscillators. Equilibrium points, stable limit cycles, and divergent states are found. Analytical results are compared with the numerical and experimental solutions, and a good agreement is obtained.


2017 ◽  
Vol 137 (6) ◽  
pp. 834-844
Author(s):  
Ryo Hotchi ◽  
Kotaro Hashikura ◽  
Akira Kojima ◽  
Taisuke Masuta

Author(s):  
R. Z. Aminov ◽  
A. N. Bayramov ◽  
M. V. Garievskii

The paper gives the analysis of the problem of the primary current frequency regulation in the power system, as well as the basic requirements for NPP power units under the conditions of involvement in the primary regulation. According to these requirements, the operation of NPPs is associated with unloading and a corresponding decrease in efficiency. In this regard, the combination of nuclear power plants with a hydrogen complex is shown to eliminate the inefficient discharge mode which allows the steam turbine equipment and equipment of the reactor facility to operate in the basic mode at the nominal power level. In addition, conditions are created for the generation and accumulation of hydrogen and oxygen during the day, as well as additionally during the nighttime failure of the electrical load which allows them to be used to generate peak power.  The purpose of the article is to assess the systemic economic effect as a result of the participation of nuclear power plants in combination with the hydrogen complex in the primary control of the current frequency in the power sys-tem, taking into account the resource costs of the main equipment. In this regard, the paper gives the justification of cyclic loading of the main equipment of the hydrogen complex: metal storage tanks of hydrogen and oxygen, compressor units, hydrogen-oxygen combustion chamber of vapor-hydrogen overheating of the working fluid in the steam turbine cycle of a nuclear power plant. The methodological foundations for evaluating the working life of equipment under cyclic loading with the participation in the primary frequency control by the criterion of the growth rate of a fatigue crack are described. For the equipment of the hydrogen complex, the highest intensity of loading is shown to occur in the hydrogen-oxygen combustion chamber due to high thermal stresses.  The system economic effect is estimated and the effect of wear of the main equipment under cyclic loading is shown. Under the conditions of combining NPP power units with a hydrogen complex, the efficiency of primary reg-ulation is shown to depend significantly on: the cost of equipment subjected to cyclic loading; frequency and intensity of cyclic loading; the ratio of the tariff for peak electricity, and the cost of electricity of nuclear power plants.  Based on the developed methodology for assessing the effectiveness of the participation of nuclear power plants with a hydrogen complex in the primary frequency control, taking into account the damage to the equipment, the use of the hydrogen complex is shown to provide a tangible economic effect compared with the option of unloading nuclear power plants with direct participation in frequency control.


2020 ◽  
Vol 15 (4) ◽  
pp. 294
Author(s):  
Juan Federico Villa Sierra ◽  
Rosa E. Correa ◽  
Juan M. Ramírez

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