Comparison on bidirectional inverter using open loop and closed loop system

Author(s):  
J. AntonyAlexander ◽  
Anand Raj ◽  
J. Suganthi Vinodhini
Author(s):  
Wayne Maxwell ◽  
Al Ferri ◽  
Bonnie Ferri

This paper extends the use of closed-loop anytime control to systems that are inherently unstable in the open-loop. Previous work has shown that anytime control is very effective in compensating for occasional missed deadlines in the computer processor. When misses occur, the control law is truncated or partially executed. However, the previous work assumed that the open-loop system was stable. In this paper, the anytime strategy is applied to an inverted pendulum system. An LQR controller with estimated state feedback is designed and decomposed into two stages. Both stages are implemented most of the time, but in a small percentage of time, only the first stage is applied, with the resulting closed-loop system being unstable for short periods of time. The statistical performance of the closed-loop system is studied using Monte-Carlo simulations. It is seen that, on average, the closed-loop performance is very close to that of the full-order controller as long as the miss rate is relatively small. However, the variance of the response shows much higher dependence on the miss rate, suggesting that the response becomes more unpredictable. At a critical value of miss rate, the closed-loop system is unstable. The critical miss rate found through simulation is seen to correlate well with the results of a deterministic stability analysis. The statistics on the settling time are also studied, and shown to grow longer as the miss rate increases. The transient behavior of the system is studied for a range of initial conditions.


1995 ◽  
Vol 117 (4) ◽  
pp. 484-489
Author(s):  
Jenq-Tzong H. Chan

A correlation equation is established between open-loop test data and the desired closed-loop system characteristics permitting control system synthesis to be done on the basis of a numerical approach using experimental data. The method is applicable when the system is linear-time-invariant and open-loop stable. The major merits of the algorithm are two-fold: 1) Arbitrary placement of the closed-loop system equation is possible, and 2) explicit knowledge of an open-loop system model is not needed for the controller synthesis.


Author(s):  
Z Ren ◽  
G G Zhu

This paper studies the closed-loop system identification (ID) error when a dynamic integral controller is used. Pseudo-random binary sequence (PRBS) q-Markov covariance equivalent realization (Cover) is used to identify the closed-loop model, and the open-loop model is obtained based upon the identified closed-loop model. Accurate open-loop models were obtained using PRBS q-Markov Cover system ID directly. For closed-loop system ID, accurate open-loop identified models were obtained with a proportional controller, but when a dynamic controller was used, low-frequency system ID error was found. This study suggests that extra caution is required when a dynamic integral controller is used for closed-loop system identification. The closed-loop identification framework also has significant effects on closed-loop identification error. Both first- and second-order examples are provided in this paper.


Author(s):  
Shiming Duan ◽  
Jun Ni ◽  
A. Galip Ulsoy

Piecewise affine (PWA) systems belong to a subclass of switched systems and provide good flexibility and traceability for modeling a variety of nonlinear systems. In this paper, application of the PWA system framework to the modeling and control of an automotive all-wheel drive (AWD) clutch system is presented. The open-loop system is first modeled as a PWA system, followed by the design of a piecewise linear (i.e., switched) feedback controller. The stability of the closed-loop system, including model uncertainty and time delays, is examined using linear matrix inequalities based on Lyapunov theory. Finally, the responses of the closed-loop system under step and sine reference signals and temperature disturbance signals are simulated to illustrate the effectiveness of the design.


In this paper, the power from a solar PV panel 20VDC, 12.5ADC is used for charging an electric vehicle battery (12V, 7Ah) with the help of an isolated dc-dc converter in an efficient manner. The power rating maintained in the system is around (200-250) W. The parasitic circuit analysis is carried out theoretically. The zero voltage transition (ZVT) technique is implemented at the inverter stage and an isolation transformer (1:1) is used for source-load isolation purposes. In order to achieve ZVT, a proper design procedure is followed and a pulse triggering technique is carried out at the switching element. The designed values of the parasitic elements are used in the Simulink tool. The open loop and closed loop system of the proposed converter are simulated in MATLAB Simulink package. In the open loop system, an irradiation analysis carried out similarly closed loop has reference voltage variation analysis in order to verify the system stability at the various operating condition. The problem of transients in open loop output is rectified in the closed loop operation. The MPP and PI control technique is initiated in the closed loop system for better performance. The MPP technique used is incremental conductance method for tracking maximum power from the PV array.


2003 ◽  
Vol 9 (9) ◽  
pp. 1041-1056 ◽  
Author(s):  
M. Moallem ◽  
R. V. Patel ◽  
K. Khorasani

In this paper, a multi-objective optimization index is introduced for improving the dynamic behavior of an actuated structurally flexible arm through geometric shape design. The improvement in the dynamic behavior is achieved by defining a vector optimization cost function. This cost function is associated with the frequency of the lowest system zero when joint angles are taken as outputs, the gain sensitivity of open-loop system modes, and the gain sensitivity of the closed-loop system modes at its transmission zeros. Moreover, a general relationship is obtained between the system pole and zero locations. In particular, it is shown that the magnitude of each system zero is smaller than a corresponding flexural mode and thus the smallest zero always occurs before the smallest pole and should therefore be considered in structural shape design. The design method is applied for finding an optimized structural shape for a single-link flexible arm. The optimized link is shown to yield superior robustness and performance characteristics in a closed-loop system when compared to the non-optimized uniform link. Thus, simpler control schemes can be utilized for the optimized flexible-link system compared to the non-optimized case.


Volume 3 ◽  
2004 ◽  
Author(s):  
Robert A. Leishear ◽  
Jeffrey H. Morehouse

The effects of fluid transients, or water hammer, in closed loop systems are somewhat different than those observed in open ended systems. The open loop system has received much attention in the literature, not so for the closed system. The generally accepted method of characteristics (MOC) technique was applied herein to investigate closed loop systems. The magnitudes of the pressures during fluid transients were investigated for examples of rapid valve closures, and the operations of parallel pumps. The effects of trapped air in the system were also considered for these examples. To reduce the pressures caused by the transients, the installation of slow closing valves were evaluated for different conditions.


Author(s):  
Orkun Simsek ◽  
Ayse Ilden Bayrak ◽  
Sinem Karatoprak ◽  
Atilla Dogan

2012 ◽  
Vol 442 ◽  
pp. 315-320
Author(s):  
Yun Fang Feng

A design method of fractional controller has been developed to meet the five different specifications, including for the closed-loop system robustness. The specifications of cross frequency, phase to get financing ϕ meters and robustness and complete performance curve based on level off the stage of open loop system, ensure damping is worse reaction time of model uncertainty gain change.


2012 ◽  
Vol 252 ◽  
pp. 23-26
Author(s):  
Xue Peng Liu ◽  
Dong Mei Zhao

Through the closed loop system response curve of the approximate treatment and the concept of dominant pole, combined with the root track analysis, the most similar to the open loop system model in applied mechanics is obtained. In the process of the closed-loop system model, the friction and gear clearance is considered for manufacturing system. The path planning is proposed for wheeled mobile robots


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