1,720,981 research outputs found
Design and Experimental Validation of an Embedded Sliding Mode Controller for Voltage Regulation With SEPIC Converters
No full textThis article addresses the challenge of regulating the output voltage in single-end primary inductor converters (SEPICs) and introduces a practical solution based on the generation of second-order suboptimal sliding modes (2-SOSM). In contrast to the common assumption of a lossless SEPIC, in this article, a lossy SEPIC is explored. A concise mathematical representation of its model is presented, and the equilibrium point is explicitly defined. Using only the output voltage as a measurement, it is proven that the proposed 2-SOSM strategy achieves finite-time convergence of the output voltage with its reference. The proposed method effectively handles saturation constraints on the control variable, ensuring that the SEPIC duty ratio remains between 0 and 1. Furthermore, the approach proves to be robust to variations in the load resistor. The experimental analysis validates the effectiveness of our proposal and highlights its practical benefits. A comparison with a standard proportional integral control on an embedded platform underscores the superiority of the adopted approach
Sliding Mode Observer-Based Finite Time Control Scheme for Frequency Regulation and Economic Dispatch in Power Grids
No full textIn this brief, a novel sliding mode (SM) observer-based scheme is proposed to achieve frequency regulation and economic dispatch (ED) in power grids composed of interconnection of generators and load buses. The ED problem is addressed in two steps. Assuming only the voltage phase angles are measured, in the first step a network of heterogeneous SM observers, suitably interconnected in a distributed fashion, is created to estimate both frequency deviations and unknown power levels associated with each bus. In the second step, the observer scheme is coupled with an SM control strategy which is able to reach the optimal value of the control input in each generator bus in finite time. The scheme is assessed via the IEEE 39 bus benchmark, and a comparison with existing control methods is provided
Sliding Mode Based Dynamic State Estimation for Synchronous Generators in Power Systems
Full text linkThis is the author accepted manuscript. The final version is available from IEEE via the DOI in this record This letter deals with the design of a robust sliding mode observer for dynamic state estimation applied to synchronous generators in power systems. Assuming only the frequency deviation of the generator is measured via phasor measurement units, we use a robust sliding mode estimation technique to dynamically reconstruct the rotor angle and the transient voltage. The adopted estimation technique is insensitive to matched bounded uncertainties affecting the dynamics of the synchronous generator. A stability analysis and tuning rules for the observer are also provided. Numerical simulations confirm the validity of the approach
Distributed Super-Twisting Sliding Mode Observers for Fault Reconstruction and Mitigation in Power Networks
No full textSecond order sliding mode observers for fault reconstruction in power networks
No full textThis is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.This paper proposes a 2-sliding mode observer to detect and reconstruct a certain class of load altering
faults in a power network. The observer design is based on the recently proposed multivariable super-twisting
structure. The IEEE benchmark power networks used to test the scheme are modelled as a semi-explicit
class of differential algebraic equations (DAEs). For the purpose of developing the detection scheme, only the
phase angles of the generators are measured, which represent a subset of the differential states of the DAEs.
The objective is to estimate the differential states (the phase angles and frequencies of the generators), the
algebraic states (the phase angles of the load bus tensions) and to reconstruct a class of load altering faults
affecting the network. The proposed observer is assessed in simulation on two IEEE benchmarks: the 9-bus
and 14-bus networks, so as to verify its capability to correctly estimate the differential and algebraic states
of the network in spite of its complexity and uncertainty. Moreover, the capability of the proposed scheme
to detect the presence of a load altering fault, to exactly identify its position in the network, and to precisely
reconstruct the shape of the fault itself is shown and discussed
Load alteration fault detection and reconstruction in power networks modelled in semi-explicit differential algebraic equation form
No full textA Super-Twisting-Like Sliding Mode Observer for Frequency Reconstruction in Power Systems: Discussion and Real Data Based Assessment
No full textDistributed observers for state estimation in power grids
No full textIn this paper an estimation scheme for a power grid based on distributed observers is presented. Assuming that the only measurements available are the generator phase angles, our approach allows us to consider an observer for each bus of the power grid, exploiting on only knowledge of local information about the power system. In particular, we design a super-twisting-like sliding mode observer for each generator bus and a so-called “algebraic observer” for each load bus, based on a distributed iterative algorithm. The proposed scheme is able to deal with power grid changes that may involve the insertion of new generators or new power transmission lines affecting the grid topology. Numerical examples and simulations confirm the validity of our approach
Anti-windup for a class of partially linearisable non-linear systems with application to wave energy converter control
No full textThis paper studies the anti-windup (AW) problem for a certain class of non-linear systems, in which the plant is globally quadratically stable and also partially linearisable by a suitably chosen non-linear feedback control law. Three types of AW compensators are proposed for this type of non-linear system: The first one is a non-linear extension of the popular linear internal model control (IMC) scheme; the second one has a similar structure to the IMC AW compensator yet is of reduced order and has entirely linear dynamics; and the third one is again a linear AW compensator, but can endow the closed-loop system with some sub-optimal performance properties. All three AW compensators are able to provide global exponential stability guarantees for the aforementioned class of systems. This work was inspired by a wave energy application whose dynamics fall into the class of systems studied in this study. Simulation results show the efficacy of the three AW compensators when applied to the wave energy application.</p
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