基于哈密顿能量理论的发电机励磁与ASVG协调控制

针对含有先进静止无功发生器(ASVG)的单机无穷大系统,建立了4阶非线性状态空间数学模型.基于Hamilton能量函数理论,设计了ASVG安装点电压与发电机励磁的新型非线性协调控制器.数字仿真结果表明,在系统遭受到较大干扰的情况下,所设计的控制器可同时满足发电机励磁与ASVG装设处电压的暂态稳定性要求.     

计及螺旋桨负载的船舶电力系统协调控制设计

推进负载对船舶电网的暂态稳定性影响是船电系统的主要特征之一.本文基于非线性鲁棒L2干扰抑制控制方法,研究了具有螺旋桨负荷的船舶电力系统中的励磁与调速的协调控制问题,在充分分析了柴油发电机组的非线性数学模型及其螺旋桨负载的相互耦合的非线性动态结构特性的基础上,提出backstepping控制技术与L2干扰抑制相结合的综合协调控制策略来设计控制器.该控制器在保证系统稳定的条件下,有效地抑制干扰对发电机系统电压和频率的影响.仿真表明,在给系统突加螺旋桨负载的情况下,该控制器能有效地抑制负载对系统性能的影响,验证了控制器的有效性.     

基于自适应滑模的喷水推进船舶航向控制

关于船舶航行优化控制,针对喷水推进船舶的航向稳定性控制问题,根据模型中非线性水动力不确定性和外界干扰,提出了基于PID增益调节的自适应滑模控制方法, 并利用Lyapunov稳定性理论证明控制方法的稳定性.控制方法对于模型参数摄动和外界干扰有较好的鲁棒性,PID增益参数的选择可通过在线自适应学习获得,采用边界层方法对设计的滑模控制器的高频抖振加以合理抑制.以一艘喷水推进船舶为例,进行了航向改变的仿真,结果表明设计的控制器具有船舶操纵的良好动态性能,且具有超调小、鲁棒性强的优点,更加符合船舶航向实时控制的工程要求.     

基于矢量控制的船舶主推进电机控制仿真研究

本文介绍了船舶电力推进系统的基本结构,分析了异步电动机的数学模型,根据矢量控制的基本原理,建立了异步电动机带螺旋桨负载的矢量控制调速系统的仿真模型,并通过仿真实验证明了异步电动机的矢量控制调速系统明显提高了船舶推进系统的性能.     

船舶电站柴油发电机组H2/H∞控制器的研究

船舶电力系统的稳定性主要取决于船舶电站柴油发电机组转速和电压的响应特性,转速和电压相互作用,对两者进行综合控制非常必要。本文将混合H_2/H_∞控制理论应用于柴油机调速系统的设计,将柴油机调速系统的性能要求转化为标准混合H_2/H_∞控制问题。计算机仿真结果表明,利用线性矩阵不等式(LMI)方法所设计的混合H_2/H_∞调速器能在考虑模型不确定性的情况下,有效地提高系统的动态精确度和抑制扰动的能力,解决了转速和电压的综合控制问题,改善了船舶电力系统的稳定性。     

基于参考模型的电力推进船舶航向滑模控制器设计

针对全回转舵浆的电力推进船舶航向控制问题,基于等价舵效建立的船舶回转运动响应方程,设计了基于参考模型的滑模控制器。该控制器含有两个滑模控制子系统,其一用来控制参考模型,以获得理想的动态响应;另一个以前者每个控制周期对应的状态为控制目标输入,引导船舶航向收敛于设定值。仿真结果表明,在满足全回转舵浆回转角幅值与速度的限制下,该方法能够有效解决滑模控制输入的强抖振问题,能降低滑模控制输入的要求,且具有良好的鲁棒性与控制效果。     

基于Hamilton函数方法的多机多负荷电力系统分散励磁控制

采用Hamilton函数方法研究了多机多负荷电力系统的励磁控制问题. 首先, 通过预置状态反馈完成了系统的耗散Hamilton实现. 然后, 基于该耗散实现形式设计了非线性分散励磁控制器, 分析了闭环系统的稳定性. 该控制器能充分利用系统内在的功率平衡特性. 仿真结果验证了控制策略的有效性.     

船舶电站柴油发电机组H2/H∞控制器的仿真研究

为了提高船舶电站柴油机调速系统的动态精确度,抑制负荷的扰动,将混合H2/H∞控制理论应用于柴油机调速系统的设计,将柴油机调速系统的性能要求转化为标准混合H2/H∞控制问题。计算机仿真结果表明,利用线性矩阵不等式方法所设计的混合H2/H∞调速器能在考虑模型不确定性的情况下,有效地提高了系统的动态精确度和抑制扰动的能力,改善了船舶电力系统频率的稳定性。     

基于西门子PLC的船舶调距桨控制系统设计

可调螺距螺旋桨（以下简称调距桨）是船舶推进系统的核心设备。随着船舶推进系统在响应速度和操纵性能等方面提出更高的要求,本文采用西门子PLC及其PROFIBUS现场总线设计调距桨控制系统,旨在提高调距桨的实时性、操纵性、稳定性和可靠性。     

Sampling-based self-triggered coordination control for multi-agent systems with application to distributed generators

This work investigates the coordination control problem for multiple distributed generation (DG) units with a hierarchical control structure. At the secondary control level, an event-triggered power sharing strategy based on the concept of multi-agent consensus has been proposed for the DG coordination control. Unlike existing consensus-based DG control approaches, the proposed control algorithm is based on sampled data. Thus the event triggering and controller updating actions can only be executed at the sampling time instants. To further reduce the amount of communication among DGs, the proposed event-triggered algorithm is extended to a self-triggered algorithm, where the inter-agent communication transmission is no longer required to be executed at each sampling time instant. The case study results show that the self-triggered algorithm can achieve nearly the same performance on DG coordination as that of the event-triggered algorithm, while significantly reduces the amount of communication.     

Adaptive H-infinity control of synchronous generators with steam valve via Hamiltonian function method

Based on Hamiltonian formulation, this paper proposes a design approach to nonlinear feedback excitation control of synchronous generators with steam valve control, disturbances and unknown parameters. It is shown that the dynamics of the synchronous generators can be expressed as a dissipative Hamiltonian system, based on which an adaptive H-infinity controller is then designed for the systems by using the structure properties of dissipative Hamiltonian systems. Simulations show that the controller obtained in this paper is very effective.     

基于交流跟踪的同步发电机最优励磁控制技术研究

针对同步发电机采用传统PID控制不能很好地满足电力系统对抑制振荡、提高动态稳定极限等方面要求的问题,提出了一种基于交流跟踪的同步发电机最优励磁控制方法;给出了基于拉格朗日方法的同步发电机励磁系统偏差线性化模型,分析了最优励磁控制量的确定方法,建立了基于最优励磁控制方法的同步发电机系统仿真模型。仿真结果表明,与传统PID控制方法相比,最优励磁控制方法能够实时控制同步发电机励磁系统,确保了同步发电机的输出稳定性。     

Supervisory control based on minimal cuts and Petri net sub-controllers coordination

This paper addresses the synthesis of Petri net (PN) controller for the forbidden state transition problem with a new utilisation of the theory of regions. Moreover, as any method of control synthesis based on a reachability graph, the theory of regions suffers from the combinatorial explosion problem. The proposed work minimises the number of equations in the linear system of theory of regions and therefore one can reduce the computation time. In this paper, two different approaches are proposed to select minimal cuts in the reachability graph in order to synthesise a PN controller. Thanks to a switch from one cut to another, one can activate and deactivate the corresponding?PNcontroller. An application is implemented in a flexible manufacturing system to illustrate the present method. Finally, comparison with previous works with experimental results in obtaining a maximally permissive controller is presented.     

电动汽车用感应电机动态平衡点的反馈耗散Hamilton控制

针对电动汽车行驶过程中路况变化频繁,其对应的配套感应电机给定转速和负载不断变化,从而导致系统平衡点也随之变化的特点和忽略铁损引起的控制不精确的问题,研究了基于动态平衡点的计及电动汽车用感应电机反馈耗散Hamilton控制问题.首先根据感应电机的工作特性计算出平衡点,然后选取适当的状态反馈,通过预置反馈的方法建立了系统的动态模型,并基于能量耗散特性实现了对电动汽车用感应电机在动态平衡点处的反馈耗散Hamilton控制,保证了整个系统的全局稳定性.最后仿真结果验证了该控制策略的有效性.     

A post-processing method for true random number generators based on hyperchaos with applications in audio-based generators

True random number generators (TRNG) are important counterparts to pseudorandom number generators (PRNG), especially for high security applications such as cryptography. They produce unpredictable, non-repeatable random sequences. However, most TRNGs require specialized hardware to extract entropy from physical phenomena and tend to be slower than PRNGs. These generators usually require post-processing algorithms to eliminate biases but in turn, reduces performance. In this paper, a new post-processing method based on hyperchaos is proposed for software-based TRNGs which not only eliminates statistical biases but also provides amplification in order to improve the performance of TRNGs. The proposed method utilizes the inherent characteristics of chaos such as hypersensitivity to input changes, diffusion, and confusion capabilities to achieve these goals. Quantized bits of a physical entropy source are used to perturb the parameters of a hyperchaotic map, which is then iterated to produce a set of random output bits. To depict the feasibility of the proposed post-processing algorithm, it is applied in designing TRNGs based on digital audio. The generators are analyzed to identify statistical defects in addition to forward and backward security. Results indicate that the proposed generators are able to produce secure true random sequences at a high throughput,which in turn reflects on the effectiveness of the proposed post-processing method.     

基于Hamilton理论的可逆冷带轧机速度张力系统无张力计控制

基于反馈耗散Hamilton理论研究了可逆冷带轧机速度张力系统的无张力计控制问题. 首先,对系统速度张力外环(主轧机速度环和左、右卷取机张力控制环)进行预反馈控制, 并采用反馈耗散Hamilton理论完成了速度张力外环控制器的设计. 其次, 为了实现系统的无张力计控制及对摄动参数的自适应估计, 基于"扩张系统+反馈"方法完成了系统速度张力外环自适应状态观测器的设计. 再次, 为了实现可逆冷带轧机主轧机速度和左、右卷取机张力间的协调控制及对外扰不确定项的干扰抑制, 基于backstepping方法完成了系统电流内环鲁棒控制器的设计. 理论分析表明, 所提出的控制方法能够保证闭环系统的鲁棒稳定性. 最后, 基于某1422mm可逆冷带轧机速度张力系统的实际数据进行仿真, 并同串级PI控制方法相比较, 结果验证了本文所提方法的有效性.     

Finite-time coordination in multiagent systems using sliding mode control approach

Finite-time stability in dynamical systems theory involves systems whose trajectories converge to an equilibrium state in finite time. In this paper, we use the notion of finite-time stability to apply it to the problem of coordinated motion in multiagent systems. Specifically, we consider a group of agents described by fully actuated Euler–Lagrange dynamics along with a leader agent with an objective to reach and maintain a desired formation characterized by steady-state distances between the neighboring agents in finite time. We use graph theoretic notions to characterize communication topology in the network determined by the information flow directions and captured by the graph Laplacian matrix. Furthermore, using sliding mode control approach, we design decentralized control inputs for individual agents that use only data from the neighboring agents which directly communicate their state information to the current agent in order to drive the current agent to the desired steady state. Sliding mode control is known to drive the system states to the sliding surface in finite time. The key feature of our approach is in the design of non-smooth sliding surfaces such that, while on the sliding surface, the error states converge to the origin in finite time, thus ensuring finite-time coordination among the agents in the network. In addition, we discuss the case of switching communication topologies in multiagent systems. Finally, we show the efficacy of our theoretical results using an example of a multiagent system involving planar double integrator agents.