Key words: dynamic model, transmission, traction, hydraulic. The conclusion is that when the speed increases a tendency of pump flow growing occurs, but after that it comes back to the initial value.
The paper presents the methodology and the results from the analysis by numerical simulation of a self adaptive hydraulic transmission in closed circuit for low power wind turbines.
buletinul institutului politehnic din iaşi - Universitatea Tehnică
In order to analyze the simulation model, realised using Simulink, the pump drive speed was considered as input value. Based on the resulted unit step responses, the system has a good working behaviour, stable dynamically to the wind speed variation and also to the load variations at the motor shaft. Key words: hydraulic transmission, wind turbine, Simulink, unit steps.
Introduction The wind energy transmitted hidraulically to the ground represents an actual research trend from complex programs, dealing with the non conventional energy sources.
The wind turbines with horizontal axis and low power, fitted with adaptive hidraulic transmissions, may run with variable speed Bej,Spera, The wind turbines run under a rigorous control of speed and power at the electrical generator shaft. First method is recommended especially for the medium and high power turbines, connected to a local or speed dating în manhattan ks network, because this type of solutions are increasing the turbine complexity, the costs and the static and dynamic loads, determining loss of reliability and great maintenance costs.
The authors are proposing a structure for a closed circuit hydraulic transmission, self adaptive. This transmission is then studied when running in dynamic regime by analyzing the unit step responses at step variations of the pump speed and consumer´s load.
Începe să conversezi chiar acum!
The Structure of the Adaptive Hydraulic Transmission The hydraulic transmission with closed circuit and self adaptive control has the structure presented in Fig. The transmission module consists in the pump 12 with variable flow and the hydraulic reversible motor 16, connected in closed circuit. The pump 12 is a double pump with low flow, which supplies the closed circuit, in order to compensate the oil losses from the circuit and to command the flow used in the circuit for setting up the pump 12 disc inclination angle.
Simulation of the wind speed variation, which determines a speed variation at the pump 12 axis, is done with the capacity motor 13, remote by the frequency converter CF. Simulation of the load at the rotary hydraulic motor shaft 16 is realized through the loading module.
- The paper presents the methodology and the results from the analysis by numerical simulation of a self adaptive hydraulic transmission in closed circuit for low power wind turbines.
- The examples that we give consist in some comparisons between Romanian and English in order to point out the difficulties that the English as a second language teachers keep in mind while planning the article lessons.
- Comitatul Phillips, Kansas - Wikipedia
The loading module consists by the rotary hydraulic motor 17, running as a pump and driven by the axis The load value for the motor 16 to drive the pump 17 is achieved using the outlet Its output pressure is measured with the transducer The flow for supplying the pump 16 is realized through the flow transducer The hydraulic transmission may run in adaptive regime only if the speed at the admission speed dating 55+ 19 is constant.
If this condition is satisfied, the adjustment of the electrical generator working parameters to the network parameters is very easy, so no more adapting elements are necessary.
Popular this week
Iaşi, t. To analyze the model´s behavior datând difuzoarele fane, implicitly the system´s functioning, the input value was considered the pump drive speed and a signals simulation block was provided for it. The simulation model for the hydraulic system is presented in Fig. The aim of the experimental tests by numerical simulation is to determine the unit responses of the hydraulic adaptive system at a step signal variation.
The reference value for the simulation tests is the speed of the shaft 19 and the input values are the speed drive of the pump 12 and the load at the hydraulic motor shaft 16 Fig. From Fig. If the pump speed changes, the variation tendency of the motor speed — registered by the speed transducer — is transmitted as a reaction signal to the servo mechanism, which modifies the stroke of the variable flow rate pump drive element.
What is dating cafe?
The increasing of the pump speed leads initially to a growing of the flow rate, the pump drive element stroke is then modified in order to decrease the flow rate and correct the speed error. This way, the motor axis speed remains constant.
From the unit responses we find out that, at speed increasing a tendency of motor speed growing occurs and then it come back to the reference value. The system is stable of oscillatory damped type. The reference value for ωM is constant.
The conclusion is that when the speed increases a tendency of pump flow growing occurs, but after that it comes back to the initial value. The functionning regime is stable, of oscillatory damped type. Analyzing the dynamic regime we can conclude that the system is stable, of oscillatory damped type.
When the speed increases, the control element stroke value is diminishing.
The reference value for ωM remains constant. The pressure drop on the rotary hydraulic motor does not change. For the inferior limit of the speed value the regime has a tendancy of instability.
Conclusions 1. The numerical simulation of the new hydraulic system confirmed a good functioning, stable at the wind speed variation variable speed at the pump axis and also at load variation of the generator motor axis. The numerical analysis aims to determine the evolution of unit step responses of the angular velocity at the hydraulic motor, of the flow for the variable flow pump, of the control element stroke and speed dating în manhattan ks the pressure drop on the rotary motor at the step variation of its load.
The analysis of the dynamic regime stressed for the considered experimental conditions tha hydraulic system stability of oscillatory damped type. Bej A. Bugarschi A. Mecanica, 42 56Timişoara Călăraşu D. Politehnica, Timişoara,pp.
Spera D. Pentru analiza comportării modelului de simulare, conceput cu ajutorul bibliotecii de functii Simulink, s-a considerat ca mărime de intrare turaŃia de antrenare a pompei. Pe baza răspunsurilor indiciale obŃinute se poate constata buna funcŃionare a sistemului, stabilă, în regim dinamic, atât la variaŃia vitezei vântului, cât şi la variaŃia sarcinii la arborele motorului generator. The work presents a classification of traction systems as a function of structure, the systems being classified into: integrally mechanic-traction systems—STIM, mechanic-hydrostatical traction -STMH and integrally traction hydrostatical systems STIH.
Meniu de navigare
Each structural speed dating în manhattan ks contains the main components from dynamic point of view: the heat engine as the source of energy, the transmission of the traction and the system for movement formed of wheels with tyres or of self-propelled equipment. For each structural model is the dynamic model to which dynamic analyses should be done by excitation accomplished by the road the runaway. The necessity of these models has been due to the study models of dynamic behavior and of traction systems comparison of different structures, mechanic, mechanic and hydraulic.
Key words: dynamic model, transmission, traction, hydraulic. Classification of Traction Systems Traction systems of the consulted technologic equipments are complex systems formed of a large number of constitutive hydrostatic, mechanic, or combinations of these components which reciprocally interacts in the aim of equipment movement in different conditions of movement.
These models permit as the influence to be studied in dynamic behavior of certain components of the transmission couplings, gearbox, cardan drive, differential, the wheel, and the tyre.
A step towards the generalization of dynamic models for the traction systems constitutes the models with a finite number of freedom degrees, which are to be considered the factors of amortization entered by the components of the system in the model besides the rigidity of the speed dating în manhattan ks components which compose the traction system structure. The parameters characterizing these systems are the rigidities of structural elements written with kij and the amortizations of the same elements written with cij.
In order to accomplish the mathematical models upon which to be studied the dating guys creole of the system to excitations produced by the dislevels of the runaway it is necessary the realization of a classification of the characteristic types of traction systems presented, taking count of the dynamic characteristics. The models must answer to the following requirements: i to take count of dynamic features produced by the components of the mechanic transmission and the way of coupling of these gearings, arbors, planetary cardans, couplings, etc.
This organization of the scheme causes the touch of functional parameters bankables for systems but and a certain dynamic behavior of this caused by the dynamic parameters of the system moments of inertia, features of rigidity and amortization, etc.
The tipology of the systems is rendered in Fig. What comprise most the complete systems of used-up mechanics for the actuation of technological equipments. Axinti,Boazu,Gilespi, The Mechanic-Hydrostatical Traction System STMH It is characterized as the fact the accomplished system between the heat engine as the source of energy and the organ of movement of equipment, formed of wheels or caterpillar, it is formed of mechanical as those presented before to which are added hydrostatic components as pumps, engine, apparatus of casting and protection, hydraulic meshes etc.