133,478 research outputs found
Hybrid Feedback Control Methods for Robust and Global Power Conversion
In this paper, the applicability and importance of hybrid system tools for the design of control algorithms for energy conversion in power systems is illustrated in two hybrid control designs, one pertaining to DC/DC conversion and the other to DC/AC inversion. In particular, the mathematical models considered consist of constrained switched differential equations/inclusions that include all possible modes of operation of the systems. Furthermore, the obtained models can be analyzed and their algorithms designed using hybrid system tools so as to attain key desired properties, such as stability, forward invariance, global convergence, and robustness. We argue that hybrid system tools provide a systematic approach for analysis and controller design of power systems. In particular, hybrid system tools usually leads to power quantities that have better performance and robustness to state perturbations. Furthermore, they provide guidelines on how to tune the controller parameters based on design requirements. These factors motivate the implementation of the proposed hybrid controllers in modern power conversion systems that use renewable energy sources. Simulations illustrating the main results and benchmark tests are included
Motion stabilization in the presence of friction and backlash: a hybrid system approach
In this paper a hybrid system approach is considered to deal with backlash and
friction induced nonlinearities in mechanical control systems. To describe the low velocity
frictional behaviour a linearized friction model is proposed. The novelty of this study is that
based on the introduced friction model, the stability theorems developed for hybrid systems can
directly be applied for controller design of mechanical systems in the presence of Stribeck friction
and backlash. During the controller design it is assumed that the size of the backlash gap is
unknown and the load side position and velocity cannot be measured. For motion control an LQ
controller is applied. A condition is formulated for the control law parameters to guarantee the
asymptotic stability of the control system. Simulation measurements were performed to confirm
the theoretical results
Minimal data rate stabilization of nonlinear systems over networks with large delays
Control systems over networks with a finite data rate can be conveniently
modeled as hybrid (impulsive) systems. For the class of nonlinear systems in
feedfoward form, we design a hybrid controller which guarantees stability, in
spite of the measurement noise due to the quantization, and of an arbitrarily
large delay which affects the communication channel. The rate at which feedback
packets are transmitted from the sensors to the actuators is shown to be
arbitrarily close to the infimal one.Comment: 16 pages; references have now been adde
Discrete Controller Design for A Hybrid Three Tank System
Systems in which the dynamical behaviour evolves based on the interaction between the continuous dynamics and the discrete dynamics, present in the system, are called hybrid systems. Traditionally such systems were analysed either as purely continuous or purely discrete systems. The interactions between discrete and continuous systems in today’s technological problems have become so important that hybrid modelling of such systems is called for. In this paper a discrete controller is designed for such a hybrid system. Hybrid modelling technique is used to model the hybrid three tank systems. The hybrid model is simulated in SIMULINK and STATEFLOW is used to design the discrete controller
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