scholarly journals Analysis of Dynamic Characteristics of a 600 kW Storage Type Wind Turbine with Hybrid Hydraulic Transmission

Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 397 ◽  
Author(s):  
Zengguang Liu ◽  
Yanhua Tao ◽  
Liejiang Wei ◽  
Peng Zhan ◽  
Daling Yue

In order to improve the efficiency and convenience of wind energy storage and solve the reproducibility of the hydraulic wind turbine, we present a storage type wind turbine with an innovative hybrid hydraulic transmission, which was adopted in the development of a 600 kW storage type wind turbine experimental platform. The whole hydraulic system of the storage type wind turbine is mainly an ingenious combination of a closed loop transmission and an open loop one, which can also be divided into three parts: hydraulic variable speed, hydraulic energy storage, power generation. For the study focusing on the capture and storage of wind energy, the mathematical model of the wind turbine except for the power generation was established under MATLAB/Simulink. A double closed loop control strategy is proposed to achieve the wind wheel speed regulation and wind energy storage. The dynamic simulations of the 600 kW storage type wind turbine experimental prototype were carried out under two different input signals. The results show that the wind wheel speed achieves the desired value at fast response and high precision using the control method given in this paper, and the proposed new storage type wind turbine is reasonable and practical.

Author(s):  
Roberto Strada ◽  
Alberto Oldani

Electro-hydraulic elevators are widely used systems, especially in low level buildings, due to their very good ratio between power generation and dynamic response. Generally, the goal of an elevator system is just to reach the floor with a precision enough to be comfortable for the passengers, without the need to follow a specific law of motion; hence an open-loop control system could be enough. Otherwise such a kind of solution reduces the number of components, bringing down the costs of production. On the other hand a complete knowledge of the mechanical system’s behaviour is required. In this work we deal with the analysis of the behaviour of a commercial hydraulic elevator driven by an open loop control that monitors the downstream pressure of the proportional valve supplying the cylinder. At the end of the paper, a closed loop solution based on the pressure measurement and on the motion time is proposed.


Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 579 ◽  
Author(s):  
Luis Galván ◽  
Juan Navarro ◽  
Eduardo Galván ◽  
Juan Carrasco ◽  
Andrés Alcántara

This paper presents a method to optimally use an energy storage system (such as a battery) on a microgrid with load and photovoltaic generation. The purpose of the method is to employ the photovoltaic generation and energy storage systems to reduce the main grid bill, which includes an energy cost and a power peak cost. The method predicts the loads and generation power of each day, and then searches for an optimal storage behavior plan for the energy storage system according to these predictions. However, this plan is not followed in an open-loop control structure as in previous publications, but provided to a real-time decision algorithm, which also considers real power measures. This algorithm considers a series of device priorities in addition to the storage plan, which makes it robust enough to comply with unpredicted situations. The whole proposed method is implemented on a real-hardware test bench, with its different steps being distributed between a personal computer and a programmable logic controller according to their time scale. When compared to a different state-of-the-art method, the proposed method is concluded to better adjust the energy storage system usage to the photovoltaic generation and general consumption.


2011 ◽  
Vol 22 (12) ◽  
pp. 1393-1407 ◽  
Author(s):  
HONGYUE DU

This paper investigates the modified function projective synchronization (MFPS) in drive-response dynamical networks (DRDNs) with different nodes, which means that systems in nodes are strictly different. An adaptive open-plus-closed-loop (AOPCL) control method is proposed, which is a practically realizable method and can overcome the model mismatched to achieve synchronization. It is well known that each of the close-loop and open-loop control method possesses some advantages and disadvantages. By combining their advantages, the open-plus-closed-loop (OPCL) control method was proposed by Jackson and Grosu. For arbitrary nonlinear dynamic systems, dx/dt = F(x,t), Jackson and Grosu proved that there exists solutions, x(t), in the neighborhood of any arbitrary goal dynamics g(t) that are entrained to g(t), through the use of an additive controlling action, K(g,x,t) = H(dg/dt,g) + C(g,t)(g(t) - x), which is the sum of the open-loop action, H(dg/dt,g), and a suitable linear closed-loop (feedback) action C(g,t). This method is a practically realizable method and robust to limited accuracy of data and effects of noise. The AOPCL control method preserve the merits of OPCL control method and its closed loop control part can be automatically adapted to suitable constants. Considering time-delays are always unavoidably in the practical situations, MFPS in DRDNs with time-varying coupling delayed is further investigated by the proposed method. Corresponding numerical simulations are performed to verify and illustrate the analytical results.


2016 ◽  
Vol 28 (2) ◽  
pp. 185-193 ◽  
Author(s):  
Pakpoom Kriengkomol ◽  
◽  
Kazuto Kamiyama ◽  
Masaru Kojima ◽  
Mitsuhiro Horade ◽  
...  

[abstFig src='/00280002/09.jpg' width=""300"" text='ASTERISK use our proposed method to walk' ]Since the industrial age began, increasing numbers of manufacturing plants have been set up to serve economic growth demand. More bridges were built simultaneously to connect cities and to make transportation more convenient. As these facilities have aged, regular maintenance has increased. The limb mechanism project we started almost 20 years ago was to deliver new types of inspection and maintenance to industrial fields. Our first prototype, a six-limb robot called Asterisk, included such capabilities as walking on ceilings, climbing and descending stairs and ladders, walking tightropes, and transversing rough terrain. Asterisk's latest version uses electromagnets to work in antigravity environments such as steel structures. Unfortunately, this presented a major danger, requiring that we replace electromagnets with electropermanent magnets (EPMs). Limitations on EPMs, however, required a new control strategy. We propose and compare three control methods -- open-loop control, closed-loop control using torque feedback, and closed-loop control using angle feedback -- in the sections that follow. Our objective is to determine the best control for inspection robots having electropermanent magnets but not using additional sensors.


2021 ◽  
Author(s):  
Liang Liao

In this thesis, a new approach is presented for the modelling and control of an automated polishing/deburring process that utilizes a dual-purpose complaint toolhead mounted on a parallel tripod robot. This toolhead has a pneumatic spindle that can be extended and retracted by three pneumatic actuators to provide tool compliance. By integrating a pressure sensor and a linear encoder, this toolhead can be used for polishing and deburring. For the polishing open-loop control, the desired tool pressure is pre-planned based on the given part geometry. To improve control performance, a closed-loop controller is applied for pressure tracking through pressure sensing. For the deburring control, another closed-loop controller is applied to regulate the tool length through tool extension sensing. The two control methods have been tested and implemented on a polishing/deburring robot, and the experiment results demonstrate the effectiveness of the presented methods. To future improve the control performance, an adaptive controller is developed to deal with the uncertainties in the compliant tool. This control method combines the adaptive control theory with the constant stress theory of the contact model. A recursive last squares (RLS) estimator is developed to estimate the pneumatic plant model, and then a minimum-degree pole placement (MDPP) is applied to design a self-tuning controller. Afterwards, the simulation and experiment results of the proposed controller are presented and discussed. Finally, a nonlinear model of the pneumatic plant is developed. The nonlinear controller developed by using feedback linearization method is applied on the nonlinear pneumatic system of the compliant toolhead. The simulation is carried out to test the effectiveness of the pressure tracking for the polishing process.


Author(s):  
Dazhou Geng ◽  
Qijuan Chen ◽  
Yang Zheng ◽  
Xuhui Yue ◽  
Donglin Yan

The stabilization of power take-off (PTO) is imperative especially under circumstances of fluctuating input wave energy. In this paper, a flow control valve is introduced to optimize the transient process of the hydraulic PTO, which can contribute to a quicker adjustment and a stronger stability. Under variations of input power and load torque in transient process, an open-loop control method and a closed-loop control method are proposed as the opening law of the above valve, and the hydraulic motor speed, the pressure at the accumulator inlet and the generated power are chosen as indicators to examine the regulation performance. Then, the synergic effect of the flow control valve and the accumulator in the transient process is discussed. The effectiveness of the two presented control methods on the fluctuation suppression is respectively tested and compared in both regular wave and irregular wave situations via simulation. To validate the practical effectiveness of the proposed methods, field experiments are conducted. The results demonstrate that the open-loop control can only improve the damping ability of the hydraulic PTO in the speed raising stage, while the closed-loop control can improve the stability both in the speed raising stage and in the load increasing stage.


2017 ◽  
Vol 36 (1) ◽  
pp. 68-85 ◽  
Author(s):  
Janis Edelmann ◽  
Andrew J Petruska ◽  
Bradley J Nelson

In this paper we apply Cosserat rod theory to catheters with permanent magnetic components that are subject to spatially varying magnetic fields. The resulting model formulation captures the magnetically coupled catheter behavior and provides numerical solutions for rod equilibrium configurations in real-time. The model is general, covering cases with different catheter geometries, multiple magnetic components, and various boundary constraints. The necessary Jacobians for quasi-static, closed-loop control using an electromagnetic coil system and a motorized advancer are derived and incorporated into a visual-feedback controller. We address the issue of solution bifurcations caused by the magnetic field by proposing an additional, stabilizing control method that makes use of system redundancies. We demonstrate the effectiveness of the model by performing 3D tip-position trajectories with root-mean-square distance errors of 2.7 mm in open-loop, 0.30 mm in closed-loop, and 0.42 mm in stabilizing closed-loop modes. The stabilizing controller achieved on average a factor of 1.6 increase in the restoring wrenches for the least stable direction.


2021 ◽  
Author(s):  
Liang Liao

In this thesis, a new approach is presented for the modelling and control of an automated polishing/deburring process that utilizes a dual-purpose complaint toolhead mounted on a parallel tripod robot. This toolhead has a pneumatic spindle that can be extended and retracted by three pneumatic actuators to provide tool compliance. By integrating a pressure sensor and a linear encoder, this toolhead can be used for polishing and deburring. For the polishing open-loop control, the desired tool pressure is pre-planned based on the given part geometry. To improve control performance, a closed-loop controller is applied for pressure tracking through pressure sensing. For the deburring control, another closed-loop controller is applied to regulate the tool length through tool extension sensing. The two control methods have been tested and implemented on a polishing/deburring robot, and the experiment results demonstrate the effectiveness of the presented methods. To future improve the control performance, an adaptive controller is developed to deal with the uncertainties in the compliant tool. This control method combines the adaptive control theory with the constant stress theory of the contact model. A recursive last squares (RLS) estimator is developed to estimate the pneumatic plant model, and then a minimum-degree pole placement (MDPP) is applied to design a self-tuning controller. Afterwards, the simulation and experiment results of the proposed controller are presented and discussed. Finally, a nonlinear model of the pneumatic plant is developed. The nonlinear controller developed by using feedback linearization method is applied on the nonlinear pneumatic system of the compliant toolhead. The simulation is carried out to test the effectiveness of the pressure tracking for the polishing process.


Author(s):  
S. G. Ignatiev ◽  
S. V. Kiseleva

Optimization of the autonomous wind-diesel plants composition and of their power for guaranteed energy supply, despite the long history of research, the diversity of approaches and methods, is an urgent problem. In this paper, a detailed analysis of the wind energy characteristics is proposed to shape an autonomous power system for a guaranteed power supply with predominance wind energy. The analysis was carried out on the basis of wind speed measurements in the south of the European part of Russia during 8 months at different heights with a discreteness of 10 minutes. As a result, we have obtained a sequence of average daily wind speeds and the sequences constructed by arbitrary variations in the distribution of average daily wind speeds in this interval. These sequences have been used to calculate energy balances in systems (wind turbines + diesel generator + consumer with constant and limited daily energy demand) and (wind turbines + diesel generator + consumer with constant and limited daily energy demand + energy storage). In order to maximize the use of wind energy, the wind turbine integrally for the period in question is assumed to produce the required amount of energy. For the generality of consideration, we have introduced the relative values of the required energy, relative energy produced by the wind turbine and the diesel generator and relative storage capacity by normalizing them to the swept area of the wind wheel. The paper shows the effect of the average wind speed over the period on the energy characteristics of the system (wind turbine + diesel generator + consumer). It was found that the wind turbine energy produced, wind turbine energy used by the consumer, fuel consumption, and fuel economy depend (close to cubic dependence) upon the specified average wind speed. It was found that, for the same system with a limited amount of required energy and high average wind speed over the period, the wind turbines with lower generator power and smaller wind wheel radius use wind energy more efficiently than the wind turbines with higher generator power and larger wind wheel radius at less average wind speed. For the system (wind turbine + diesel generator + energy storage + consumer) with increasing average speed for a given amount of energy required, which in general is covered by the energy production of wind turbines for the period, the maximum size capacity of the storage device decreases. With decreasing the energy storage capacity, the influence of the random nature of the change in wind speed decreases, and at some values of the relative capacity, it can be neglected.


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