scholarly journals A New Seamless Transfer Control Strategy of the Microgrid

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Zhaoyun Zhang ◽  
Wei Chen ◽  
Zhe Zhang

A microgrid may operate under two typical modes; the seamless transfer control of the microgrid is very important. The mode conversion controller is installed in microgrid and the control logic of master power is optimized for microgrid mode conversion. In the proposed scheme, master power is very important. The master-power is under the PQ control when microgrid is under grid-connected. And it is under V/F control when the microgrid is under islanding. The microgrid mode controller is used to solve the planned conversion. Three types of conversion are simulated in this paper. The simulation results show the correctness and validity of the mode control scheme. Finally, the implementation and application of the operation and control device are described.

Author(s):  
Reyhane Mokhtarname ◽  
Ali Akbar Safavi ◽  
Leonhard Urbas ◽  
Fabienne Salimi ◽  
Mohammad M Zerafat ◽  
...  

Dynamic model development and control of an existing operating industrial continuous bulk free radical styrene polymerization process are carried out to evaluate the performance of auto-refrigerated CSTRs (continuous stirred tank reactors). One of the most difficult tasks in polymerization processes is to control the high viscosity reactor contents and heat removal. In this study, temperature control of an auto-refrigerated CSTR is carried out using an alternative control scheme which makes use of a vacuum system connected to the condenser and has not been addressed in the literature (i.e. to the best of our knowledge). The developed model is then verified using some experimental data of the real operating plant. To show the heat removal potential of this control scheme, a common control strategy used in some previous studies is also simulated. Simulation results show a faster dynamics and superior performance of the first control scheme which is already implemented in our operating plant. Besides, a nonlinear model predictive control (NMPC) is developed for the polymerization process under study to provide a better temperature control while satisfying the input/output and the heat exchanger capacity constraints on the heat removal. Then, a comparison has been also made with the conventional proportional-integral (PI) controller utilizing some common tuning rules. Some robustness and stability analyses of the control schemes investigated are also provided through some simulations. Simulation results clearly show the superiority of the NMPC strategy from all aspects.


2007 ◽  
Vol 31 (1) ◽  
pp. 127-141
Author(s):  
Yonghong Tan ◽  
Xinlong Zhao

A hysteretic operator is proposed to set up an expanded input space so as to transform the multi-valued mapping of hysteresis to a one-to-one mapping so that the neural networks can be applied to model of the behavior of hysteresis. Based on the proposed neural modeling strategy for hysteresis, a pseudo control scheme is developed to handle the control of nonlinear dynamic systems with hysteresis. A neural estimator is constructed to predict the system residual so that it avoids constructing the inverse model of hysteresis. Thus, the control strategy can be used for the case where the output of hysteresis is unmeasurable directly. Then, the corresponding adaptive control strategy is presented. The application of the novel modeling approach to hysteresis in a piezoelectric actuator is illustrated. Then a numerical example of using the proposed control strategy for a nonlinear system with hysteresis is presented.


Author(s):  
Bennett Breese ◽  
Drew Scott ◽  
Shraddha Barawkar ◽  
Manish Kumar

Abstract Tethered drone systems can be used to perform long-endurance tasks such as area surveillance and relay stations for wireless communication. However, all the existing systems use tethers only for data and power transmission from a stationary point on the ground. This work presents a control strategy that enables a quadcopter to follow a moving tether anchor. A force feedback controller is implemented using Fuzzy Logic. Using force-based strategy provides effective compliance between the tether’s anchor and the drone. The drone can thus be controlled by mere physical movement/manipulation of tether. This enhances the safety of current tethered drone systems and simplifies the flying of drones. Fuzzy Logic provides an intuitive edge to the control of such systems and allows handling noise in force sensors. Extensive simulation results are presented in this paper showing the effectiveness of the proposed control scheme.


Author(s):  
Jikai Liu ◽  
Biao Ma ◽  
Heyan Li ◽  
Man Chen ◽  
Jianwen Chen

The cooperation mode between the engagement and disengagement clutches for vehicles equipped with Dual Clutch Transmission (DCT) is of vital importance to achieve a smooth gearshift, in particular for the downshift process as its unavoidable power interruption during the inertia phase. Hence, to elevate the performance of DCT downshifting process, an analytical model and experimental validation for the analysis, simulation and control strategy are presented. Optimized pressure profiles applied on two clutches are obtained based on the detailed analysis of downshifting process. Then, according to the analysis results, a novel control strategy that can achieve downshift task with only one clutch slippage is proposed. The system model is established on Matlab/Simulink platform and used to study the variation of output torque and speed in response to different charging pressure profiles and various external loads during downshifting process. Simulation results show that, compared with conventional control strategies, the proposed one can not only avoid the torque hole and power circulation, but shorten the shift time and reduce the friction work. Furthermore, to validate the effectiveness of the control strategy, the bench test equipped with DCT is conducted and the experiment results show a good agreement with the simulation results.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Salahuddin Abdul Rahman ◽  
Mohamed Zribi ◽  
Nejib Smaoui

The synchronous reluctance motor (SynRM) drive system is known to exhibit chaotic behavior under specified conditions. In this paper, the discrete-time sliding mode control (DSMC) technique is used to synchronize two SynRMs starting from different sets of initial conditions. The mixed variable speed reaching law is adopted in the design of the controller scheme. The parameters of the designed control scheme are tuned using a genetic algorithm (GA). Simulation results are presented to demonstrate the effectiveness of the proposed controller. In addition, the performance of the proposed control scheme is studied through simulations when bounded disturbances and mismatches between the parameters of the systems and those of the control scheme exist. The simulation results show that the designed control scheme is robust to bounded external disturbances and to mismatches in the parameters of the systems.


2012 ◽  
Vol 490-495 ◽  
pp. 1759-1762 ◽  
Author(s):  
Jian Hua Wang ◽  
Hao Xu ◽  
Fei Xie

This paper proposed a new design scheme for automatic clutch of AMT which is based on electrorheological (ER) fluid. Through analyzing the working principle and its transfer characteristics of ER fluid, it discussed the start process of vehicle and control strategy of ER Clutch. By changing the control voltage, ER clutch satisfied the requirements of evaluation indexes such as start time and impact degree. The simulation results showed that the control strategy can realize starting rapidly and steadily which would meet the start requirements of economical automobiles


Author(s):  
Veysel Gazi ◽  
Barış Fidan ◽  
Raúl Ordóñez ◽  
M. İlter Köksal

In this paper, we consider the task of tracking a maneuvering target both with a single nonholonomic agent and a swarm of nonholonomic agents. In order to achieve the tracking task, a decentralized continuous-time control scheme, which combines artificial potentials and sliding mode control techniques, is developed via constructive analysis. The effectiveness of the proposed control scheme is established analytically and demonstrated via a set of simulation results.


2014 ◽  
Vol 25 (02) ◽  
pp. 255-282 ◽  
Author(s):  
Alfio Borzì ◽  
Suttida Wongkaew

A new refined flocking model that includes self-propelling, friction, attraction and repulsion, and alignment features is presented. This model takes into account various behavioral phenomena observed in biological and social systems. In addition, the presence of a leader is included in the system in order to develop a control strategy for the flocking model to accomplish desired objectives. Specifically, a model predictive control scheme is proposed that requires the solution of a sequence of open-loop optimality systems. An accurate Runge–Kutta scheme to discretize the optimality systems and a nonlinear conjugate gradient solver are implemented and discussed. Numerical experiments are performed that investigate the properties of the refined flocking model and demonstrate the ability of the control strategy to drive the flocking system to attain a desired target configuration and to follow a given trajectory.


2013 ◽  
Vol 397-400 ◽  
pp. 1169-1173
Author(s):  
Hong Wei Tang ◽  
Xi Kun Chen ◽  
Yan Xia Gao

To adapt to the requirements of the charging and discharging of the lithium battery, the paper presents a three-level based bidirectional energy storage converter topology.It has strong adaptability and can manage the charge and discharge of multi-series and parallel battery module. The mathematical model of the converter is analyzed, and the two operation modes of the converter control strategy are studied; Analysis the feed-forward decoupling control of three-level rectifier, and the variable scale factor is used to control midpoint potential. The simulation results demonstrate the feasibility of the design.


2013 ◽  
Vol 380-384 ◽  
pp. 2962-2966
Author(s):  
Chun Guang Tian ◽  
De Xin Li ◽  
Li Xia Cai ◽  
Tian Dong ◽  
Xiao Juan Han

As one of main clean energies, wind power has been developed fast, but the fluctuations of active power at a wind farm is a huge challenge for the grid system, thus it is essential for wind farm connected into grid to detection the active power. This paper studied control strategies and detection methods of the active power at a wind farm. Simulation results showed the effective detection of active power at a wind farm can improve the characteristics of the grid and the ability of wind farm to regulate the grid and increase the scheduled ability of wind farm.


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