Sliding motion,robust control and power loss minimization in a class of non-linear switched converters

In this paper we propose a sliding mode control scheme that allows robust control of the output voltage in a class of non-linear switched converters that includes the non-inverting buck-boost, the Watkins–Johnson and the inverse of Watkins–Johnson. Using a full-state reference profile-based sliding surface, periodic signals may be tracked by the output voltage under appropriate restrictions. Furthermore, semi-infinite programming techniques are used to minimize power loses while taking into account the existence of load perturbations. The procedure consists of choosing a reference signal for the inductor current with minimum root mean square, subject to the maintenance of sliding regime under possible load variation in a set with known bounds. Realistic simulation results show a highly robust performance in the presence of load disturbances.     

Sliding mode control of boost and buck-boost power converters using method of stable system centre

Nonminimum phase tracking control is studied for boost and buck-boost power converters. The sliding mode controller is designed to track directly a causal voltage tracking profile given by an exogenous system. The nonminimum phase output tracking problem is reduced to a state tracking problem. Bounded state tracking profiles are generated by equations of stable system centre. Numerical examples demonstrate the effectiveness of the sliding mode control design.     

Sliding mode control of boost and buck‐boost power converters using the dynamic sliding manifold

Non‐minimum phase tracking control is studied for boost and buck‐boost power converters. A sliding mode control algorithm is developed to track directly a causal voltage tracking profile given by an exogenous system. The approximate causal output non‐minimum phase asymptotic tracking in non‐linear boost and buck‐boost power converters is addressed via sliding mode control using a dynamic sliding manifold (DSM). Use of DSM allows the stabilization of the internal dynamics when the output tracking error tends asymptotically to zero in the sliding mode. The sliding mode controller with DSM links features of conventional sliding mode control (insensitivity to matched non‐linearities and disturbances) and a conventional dynamic compensator (accommodation to unmatched disturbances). Numerical examples demonstrate the effectiveness of the sliding mode controller even for a known time‐varying load. Copyright © 2003 John Wiley & Sons, Ltd.     

Sliding mode control of DC‐to‐DC power converters using integral reconstructors

A sliding mode feedback controller, based on integral reconstructors is developed for the regulation of the ‘boost’ DC‐to‐DC power converter circuit conduction in continuous conduction mode. The feedback control scheme uses only output capacitor voltage measurements, as well as knowledge of the available input signal, represented by the switch positions. The robustness of the feedback scheme is tested with abusively large, unmodelled, sudden load resistance variations. Copyright © 2002 John Wiley & Sons, Ltd.     

一类多执行机构系的滑模控制设计及其应用

针对一类具有多执行机构的非线性系统,利用滑模控制和backstepping技术,研究了输出跟踪问题.针对执行机构的不同特点,利用离散执行机构实现滑模控制中的不连续控制量,利用连续执行机构实现滑模控制中的连续控制量.然后利用backstepping技术实现连续执行机构的输出对滑模控制中的连续控制量的有限时间收敛.将提出的设计方法应用于导弹直接侧向力与气动力复合控制系统设计,并进行了仿真验证.     

Finite time state and disturbance estimation for robust performance of motion control systems using sliding modes

In this paper, simultaneous state and disturbance estimation of a drive system composed of motor connected to a load is proposed. Such a system is represented by a two mass model realising in a fourth-order plant. Backlash is introduced as the nonlinear disturbance in gears which is proposed to be estimated and in turn compensated. For this motion control system, a two-stage higher order sliding-mode observer is proposed for state and backlash estimation. The novelty lies in the fact that for this fourth-order system, output is considered from the motor end only, i.e. its angular displacement. The unmeasured states consisting of output derivative, load-side angular displacement and its derivative along with backlash are estimated in finite time. This disturbance due to backlash is unmatched in nature. The estimated states and disturbance are used to devise a robust sliding-mode control. This proposed scheme is validated in simulation and experimentation.     

Sliding-mode control on slow manifolds of DC-to-DC power converters

In this article, general relationships are established among variable structure control strategies and pulse-width modulated control schemes leading to sliding modes in non-linear systems. The results are applied to the design of a sliding regime for the regulation of DC-to-DC switchmode power converters exhibiting a slow integral manifold due to time-scale separation properties among input and output circuits.     

Sliding mode cooperative motion control of dual arm manipulators

This paper presents a method for realizing cooperative control of dual-arm manipulators (RM-10A by Remotec Inc.) handling the same object in the presence of dynamic parameter uncertainties of both robots and object. When multiple robots handle the same object, both the position and the internal forces between the robots and the object should be controlled. In this paper, a sliding mode controller is derived for trajectory tracking of object position and internal forces. To show the effectiveness of the proposed controller, numerical simulations are performed for 12 axis dual-arm manipulators. This work was presented, in part, at the Third International Symposium on Artificial Life and Robotics, Oita, Japan, January 19–21, 1998     

Sliding mode control of two-level quantum systems

This paper proposes a robust control method based on sliding mode design for two-level quantum systems with bounded uncertainties. An eigenstate of the two-level quantum system is identified as a sliding mode. The objective is to design a control law to steer the system’s state into the sliding mode domain and then maintain it in that domain when bounded uncertainties exist in the system Hamiltonian. We propose a controller design method using the Lyapunov methodology and periodic projective measurements. In particular, we give conditions for designing such a control law, which can guarantee the desired robustness in the presence of the uncertainties. The sliding mode control method has potential applications to quantum information processing with uncertainties.     

基于双幂次趋近律的滑模控制方法

针对滑模控制中传统趋近律存在抖振、收敛速度慢的问题, 提出一种基于特定双幂次趋近律的滑模控制方案. 双幂次趋近律具有全局快速的固定时间收敛特性, 收敛时间存在与滑模初值无关的上界. 当系统存在有界集总扰动时, 双幂次趋近律能使滑模及其一阶导数在有限时间收敛到稳态误差界内. 仿真分析验证了所提出方法的有效性.

     

Robust nonlinear adaptive control of multiphase synchronous buck power converters

The problem of controlling multiphase synchronous buck power converters is considered. The aims are to regulate the output voltage of the converter and to ensure adequate current sharing between its different channels. Using the backstepping technique, an adaptive controller is designed based on a large-signal bilinear model of the whole multi-channel converter. A parameter projection is used to ensure that the obtained adaptive controller is robust to parasitic resistances. The controller is formally shown to meet the objectives of closed-loop asymptotic stability, output reference tracking, and equal load sharing. The attraction region depends on the uncertain parasitic impedance size, with the attraction region being larger for smaller parasitic impedances. In the ideal case of no parasitic impedances, the closed-loop asymptotic stability is global. These theoretical results are confirmed by simulation.     

Optimal control of voltage source converters under power system faults

For the integration of renewable energy in power systems, Voltage Source Converters (VSCs) must transfer power from a DC source to an AC grid with effective control of the DC voltage. An important demand is that the converters remain connected to the grid even under severe voltage perturbations. In these situations, the power transfer capability of the converter suffers a drastic reduction, which may cause over-voltages. In this paper, a multi-variable optimal control with anti-windup compensation is proposed with the aim of improving performance, especially under severe voltage faults. The proposed control scheme is evaluated by simulations using a detailed model of the VSC.     

网络控制系统的滑模多步预估控制

针对网络控制系统中出现的长时滞、网络诱导噪声和数据包丢失,提出了的滑模多步预估控制器的设计方法.首先对提出的控制器进行了描述,它利用滑模控制的强鲁棒性来克服网络诱导噪声,采用多步预估的办法来处理网络中的时滞和数据包丢失.进而对导出的闭环网络控制系统的稳定性进行了分析.最后对通过网络控制的直流电机,采用所提出的方法设计了控制器,仿真结果验证了方法的有效性.     

Sliding mode control of singular stochastic hybrid systems

This paper is concerned with the sliding mode control (SMC) of nonlinear singular stochastic systems with Markovian switching. An integral sliding surface function is designed, and the resulting sliding mode dynamics is a full-order Markovian jump singular stochastic system. By introducing some specified matrices, a new sufficient condition is proposed in terms of strict linear matrix inequality (LMI), which guarantees the stochastic stability of the sliding mode dynamics. Then, a SMC law is synthesized for reaching motion. Moreover, when there exists an external disturbance, the ?₂ disturbance attenuation performance is analyzed for the sliding mode dynamics. Some related sufficient conditions are also established.     

Sliding mode control for polytopic differential inclusion systems

The stabilization problem of polytopic differential inclusion (PDI) systems is investigated by using sliding mode control. Sliding surface is designed and sufficient conditions for asymptotic stability of sliding mode dynamics are derived. A novel feedback law is established to make the state of system reach the sliding surface in a finite time. Finally, an example is given to illustrate the validity of the proposed design.     

不确定离散时间系统的滑模可靠控制

存在状态时滞的不确定离散时间系统的的滑模可靠控制问题,其中,被控系统执行器可能发生部分故障.通过构造一种拟积分型切换面,可以保证系统状态轨迹从开始时刻就位于切换面上.利用Lyapunov稳定性理论和线性矩阵不等式技术给出了滑模动态系统渐近稳定的充分条件.而且,所设计的滑模控制律可以保证在执行器故障影响下的滑动模态仍然是可达的.数值仿真验证了本文设计方法的有效性.     

Stability of current-mode control for DC–DC power converters

DC–DC power converters are switched devices whose averaged dynamics are described by a bilinear second-order system with saturated input. In some cases (e.g., boost and buck–boost converters), the input output dynamics can be of nonminimum-phase nature. Current-mode control is the standard strategy for output voltage regulation in high dynamic performance industrial DC–DC power converters. It is basically composed by a saturated linear state feedback (inductor current and output voltage) plus an output voltage integral feedback to remove steady-state offset. Despite its widespread usage, there is a lack of rigorous results to back up its stabilization capability and to systematize its design. In this paper, we prove that current-mode control yields semiglobal stability with asymptotic regulation of the output voltage.     

Nonlinear control of power converters: a new adaptive backstepping approach

This paper proposes a new backstepping approach to nonlinear control of power converters which is attracting considerable attention in both theoretical research and practical applications. The main difference between the proposed algorithm and the existing classical adaptive backstepping method in the literature is that the adaptation mechanism does not follow the certainty‐equivalence principle. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society