Droop control strategy proposed by referring to the output power versus frequency and voltage amplitude curve of the generator is used in the true-bipolar modular multilevel converter (MMC)- high-voltage direct curren...
详细信息
ISBN:
(数字)9781728193878
ISBN:
(纸本)9781728193878
Droop control strategy proposed by referring to the output power versus frequency and voltage amplitude curve of the generator is used in the true-bipolar modular multilevel converter (MMC)- high-voltage direct current (HVdc) system. The other side of the true-bipolar MMC-HVdc system is generally connected to a large-scale new energy generation field. In this situation, people find that the oscillation problem occurs from time to time. To study systems with a high proportion of power electronics, this article respectively establishes the small-signal multi-inputmulti-output (MIMO) sequence impedance model of the ac side of a pseudo-bipolar MMC-HVdc system and a true-bipolar MMC-HVdc system considering frequency coupling. Simulation models are established on the MATLAB/Simulink platform to verify the accuracy of the established model.
This paper is concerned with designing multi-inputmulti-output (MIMO) proportional-integral-derivative (PID) control having filtered derivative terms to achieve optimal linear quadratic performance for a class of lin...
详细信息
This paper is concerned with designing multi-inputmulti-output (MIMO) proportional-integral-derivative (PID) control having filtered derivative terms to achieve optimal linear quadratic performance for a class of linear uncertain MIMO systems with norm-bounded time-varying uncertainties. A necessary and sufficient condition for existence of the PID controller is obtained in terms of rank constrained linear matrix inequalities (LMIs). Using an existing penalty-function-based approximation for matrix rank minimization, an algorithm is proposed to solve these rank constrained LMIs and find PID gains. A suitable numerical example is considered to show the efficacy of the proposed approach in ensuring robust performance as compared to the existing ones. The proposed algorithm is also tested on several benchmark examples and found to be computationally much more efficient than some well-known methods.
The paper concerns the problem of adaptive compensation of unmatched disturbances in linear time-invariant (LTI) multi-inputmulti-output (MIMO) unstable plants with multiple distinct input delays. The external distur...
详细信息
ISBN:
(纸本)9781713872344
The paper concerns the problem of adaptive compensation of unmatched disturbances in linear time-invariant (LTI) multi-inputmulti-output (MIMO) unstable plants with multiple distinct input delays. The external disturbances affect both the input and the output of the plant and are represented by multi-harmonic signals with unknown parameters (frequencies, phases, and amplitudes). The paper extends results of the paper Nikiforov et al. (2021) on adaptive compensation of unmatched disturbances to the case of distinct input delays. To overcome the problem of multiple distinct input delays, a special scheme of the disturbance prediction is proposed and used for design of the adaptive control *** (c) 2023 The Authors.
Increasing performance requirements in high-precision mechatronic systems lead to a situation where both multivariable and sampled-data implementation aspects need to be addressed. The aim of this paper is to develop ...
详细信息
Increasing performance requirements in high-precision mechatronic systems lead to a situation where both multivariable and sampled-data implementation aspects need to be addressed. The aim of this paper is to develop a design framework fora multi-inputmulti-output feedforward controller to improve continuous- time tracking performance through learning. The sampled-data feedforward controller is designed with physically interpretable tuning parameters using a multirate zero-order-hold differentiator. The developed approach enables interaction compensation for multi-input multi-output systems and the feedforward controller parameters are updated through learning. The performance improvement is experimentally validated in a multi-inputmulti-output motion system compared to the conventional feedforward controllers.
In this paper, an adaptive discrete-time sliding mode control based on reduced-order disturbance observer is proposed for discretized multi-input multi-output systems subjected to unmatching condition. By using the de...
详细信息
In this paper, an adaptive discrete-time sliding mode control based on reduced-order disturbance observer is proposed for discretized multi-input multi-output systems subjected to unmatching condition. By using the designed discrete reduced-order disturbance observer, a new sliding surface is constructed to counteract the unmatched uncertainties. Then, to guarantee a smaller width of the quasi-sliding mode domain, an adaptive reaching law is developed, whose switching gain is adaptively tuned to prevent overestimation of disturbance on the premise of ensuring the reaching condition of sliding surface;meanwhile, the ranges of the quasi-sliding mode band and attractiveness region are deduced. The proposed control algorithm has low computational complexity and needs no information about the upper bound of unmatched uncertainty. The simulations on the control of a bank-to-turn missile demonstrates that the proposed method can effectively reject unmatched disturbance and provide higher accuracy in comparison with traditional methods.
Since renewable energy sources such as PV and wind provide intermittent energy generation, this paper presents an advanced DC/DC converter that is able to set its operational mode automatically to either multi-input m...
详细信息
Since renewable energy sources such as PV and wind provide intermittent energy generation, this paper presents an advanced DC/DC converter that is able to set its operational mode automatically to either multi-inputmulti-output (MIMO) or single-inputmulti-output (SIMO) depending on the input source conditions. Power flow is controlled through the auxiliary relays added to a double-layer boost converter. Considering the transient events require fast dynamic response, model predictive control (MPC) is used to achieve the current control processes for both layers. Furthermore, the MPC is modified to adapt itself to changes in the topology. The proposed system is verified by simulations and experimentally. Results show that the proposed mode-changeable converter successfully determines the optimum power route after deciding the best operational mode in accordance with the input source conditions. Furthermore, the control method achieves a powerful and effective control process in both MIMO and SIMO modes. (C) 2020 ISA. Published by Elsevier Ltd. All rights reserved.
This paper is a development of the authors' recently published idea on a simple and generally applicable system identification algorithm based on Taguchi method. In the previous paper, the effectiveness of the alg...
详细信息
This paper is a development of the authors' recently published idea on a simple and generally applicable system identification algorithm based on Taguchi method. In the previous paper, the effectiveness of the algorithm in identifying nonlinear systems was shown. This paper presents the modified algorithm with the capability of identifying multi-inputmulti-output (MIMO) systems, and systems with unknown parameters of quite different value-ranges. Regarding the former, a contribution analysis is introduced and utilized to determine that the model between which of the input-output pairs should be identified first. The results proved that this idea significantly results in less time-cost. Moreover, the study develops the identification algorithm by adding a step of breaking down the identification process to multiple steps, each identifying a group of parameters that are in about the same value-range. Utilizing Taguchi method that includes human intelligence in the loop, the presented method effectively saved the process time and led to a more accurate estimation. In the method presented, the algorithm identifies a group of parameters at each step starting with the most contributor ones rather than identifying all of them at once. To group parameters, a contribution analysis is employed. To prove the effectiveness of the method, without loss of generality, the algorithm is applied on a multi-input single-outputsystem. The experimental test-setup used in this study is a custom-made linear series elastic actuator that is designed for lower limb exoskeletons in Ferdowsi University of Mashhad (FUM)-Robotic Laboratory. (C) 2019 Published by Elsevier Ltd.
This paper proposes a smooth second-order sliding mode controller for a class of multi-inputmulti-output mechanical systems with uncertain parameters and external disturbances. Since the control law is smooth, the ch...
详细信息
This paper proposes a smooth second-order sliding mode controller for a class of multi-inputmulti-output mechanical systems with uncertain parameters and external disturbances. Since the control law is smooth, the chattering effect that can occur with non-smooth controllers is reduced. Lyapunov-based theorems are used to prove global and finite-time convergence of the sliding mode controller. Numerical simulations are presented to illustrate the performance of the proposed controller by applying it first to a variable-length pendulum and then to a two-link robotic manipulator. For the robotic manipulator, a detailed comparison is given of the finite-time convergence and chattering properties of the proposed controller, a super-twisting controller and a super-twisting like controller.
The paper concerns the problem of adaptive compensation of unmatched disturbances in linear time-invariant (LTI) multi-inputmulti-output (MIMO) unstable plants with multiple distinct input delays. The external distur...
详细信息
The paper concerns the problem of adaptive compensation of unmatched disturbances in linear time-invariant (LTI) multi-inputmulti-output (MIMO) unstable plants with multiple distinct input delays. The external disturbances affect both the input and the output of the plant and are represented by multi-harmonic signals with unknown parameters (frequencies, phases, and amplitudes). The paper extends results of the paper Nikiforov et al. (2021) on adaptive compensation of unmatched disturbances to the case of distinct input delays. To overcome the problem of multiple distinct input delays, a special scheme of the disturbance prediction is proposed and used for design of the adaptive control law.
Approximate dynamic programming is a useful tool in solving multi-stage decision optimal control problems. In this work, we first promote the action-dependent heuristic dynamic programming method to multi-inputmulti-...
详细信息
Approximate dynamic programming is a useful tool in solving multi-stage decision optimal control problems. In this work, we first promote the action-dependent heuristic dynamic programming method to multi-inputmulti-output control system by extending its action network to multi-output form. The detailed derivation is also given. We then apply this method to the fluctuation control of a spark engine idle speed. An engine idling model is set up to verify the control effect of this method. Results here show that this method requires several iterations to suppress unbalanced combustion by manipulating spark ignition timing. This method provides an alternative for a simpler multi-inputmulti-output approximate dynamic programming scheme. Moreover, it has a faster iteration convergence effect. The derivation of this method also has a rigorous mathematical basis. Although illustrated for engines, this control system framework should also be applicable to general multi-inputmulti-output nonlinear system. Copyright (C) 2011 John Wiley & Sons, Ltd.
暂无评论