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We are considering the problem of modelling and observer design for a fleet of Plug-in Electric vehicles (PEVs) in a public station connected to a smart grid. Both charging (Grid-to-Vehicle (G2V)) and discharging (Vehicle-to-Grid (V2G)) are focused on. We first develop models of fleet dynamics in both modes. The models are 1D hyperbolic-type partial differential equations (PDEs), and their well-posed is analysed using the method of characteristics, while their discretisation is performed using the θ-scheme. Then, we design observers that provide online estimates of the state variable along the PDE domain. The design and the analysis of observers are performed using Volterra integral backstepping transformation. Finally, numerical simulations are provided that confirm the theoretical convergence results in G2V and V2G modes. [ABSTRACT FROM AUTHOR]

This paper deals with the identification of Hammerstein–Wiener models. The novelty lies in the fact that the front nonlinear block is allowed to be the memory of hysteresis type. The latter is any rate-independent hysteresis operator, that is characterised by closed limit cycles when excited by periodic input signals called 'loading-unloading' (or 'increasing-decreasing'). Designing appropriate 'loading-unloading' periodic inputs will prove to be crucial in the proposed identification method. By using such signals, the intermediary linear subsystem is made transparent and the hysteresis front block is equivalent to two static nonlinearities (i.e. the lateral borders of the limit cycle). Then, the input and output signals turn out to be related by two composed functions. A decomposition algorithm is then resorted to extract the back nonlinearity and both lateral borders of the front hysteresis operator. Finally, the impulse response of the intermediary linear subsystem is determined using a least-squares like estimator. The quality of the estimated model is checked using a theoretical analysis and simulation results. [ABSTRACT FROM AUTHOR]

Existing observers that accommodate distributed-delays are mainly designed for linear systems with continuous-time output measurements. In this paper, we seek sampled-measurements-based observers for nonlinear systems with strict-feedback globally Lipschitz dynamics and distributed-delay. Invoking the high-gain principle, we design two observers operating with sampled output measurements. In both, the delay effect is compensated for by using distributed output-predictors. The first observer involves an intersample predictor and its exponential convergence is established using a quadratic Lyapunov function. The second observer involves a zero-order-hold predictor and the exponential convergence is proved using a Lyapunov–Krasovskii functional. To the author's knowledge, it is the first time that an exponentially convergent observer is developed for nonlinear systems with output distributed-delay and sampled output measurements. [ABSTRACT FROM AUTHOR]

This paper deals with the problem of sampled-data observer design to estimate the state of health (SoH), the state of charge (SoC), and the internal temperature for batteries. The observation is based on the estimation of the battery internal resistance, which is supposed to be unknown and varying with temperature. The difficulty is that the system state equation contains an unknown parameter (which represents the internal resistance) and an output-dependent term only accessible to measurement at sampling time. The proposed approach consists of several levels of estimation and calculation using non-linear observers and fitting functions exploiting experimental data. It has been shown, using theoretical analysis, simulations, and experimental results, that the proposed method gives a novel approach to estimate the quantities (SoH, SoC, and temperature) useful for the battery management system (BMS). The point is that this approach only involves the estimation of the internal resistance of the battery. [ABSTRACT FROM AUTHOR]

We are considering the problem of observer design for a general class of state-affine systems in presence of output delay and sampling. Two novelties characterize the considered class of systems: (i) the state equation is subject to output injection involving future output values (not accessible to measurement); (ii) the injected output values come in the state equation not only through a driving term but also through the state matrix. These novel characteristics entail the loss of the system state-affine nature and lead to a new observer design problem never investigated so far. The solution we develop in this paper is a sampled-data based observer of Kalman-like type, augmented with inter-sample predictors and signal saturations. Using both Lyapunov and small-gain arguments, we show that the observer is exponentially convergent for sufficiently small sampling interval and delay, provided an observability condition is satisfied. [ABSTRACT FROM AUTHOR]

The problem of identifying parametric Wiener–Hammerstein (WH) systems is addressed within the evolutionary optimisation context. Specifically, a hybrid culture identification method is developed that involves model structure adaptation using genetic recombination and model parameter learning using particle swarm optimisation. The method enjoys three interesting features: (1) the risk of premature convergence of model parameter estimates to local optima is significantly reduced, due to the constantly maintained diversity of model candidates; (2) no prior knowledge is needed except for upper bounds on the system structure indices; (3) the method is fully autonomous as no interaction is needed with the user during the optimum search process. The performances of the proposed method will be illustrated and compared to alternative methods using a well-established WH benchmark. [ABSTRACT FROM AUTHOR]

This article addresses the problem of controlling DC-DC interleaved boost converters associated to fuel cell energy generators. The fuel cell–interleaved boost converter association powers a possibly unknown and time-varying resistance load; furthermore, interleaved boost converter parallel cells are not equipped with current sensors. The control objective is twofold: (1) the interleaved boost converter output voltage must be tightly regulated and (2) the total current carried by the interleaved boost converter must be equally shared between the different parallel branches. The complexity of the control problem lies in (i) the system non-linearity and instability of system zero dynamics with respect to output voltage, (ii) load uncertainty, and (iii) inaccessibility to measurements of all currents. The instability of the output voltage zero dynamics is addressed by reformulating all control objectives in terms of current regulation in the different converter cells. The resulting current regulation problem is dealt with by developing an adaptive output feedback controller including a collection of adaptive current regulators and estimators. Parameter adaptation is used for compensation of load uncertainty. It is shown that the proposed output feedback adaptive controller meets its objectives. This theoretical analysis is confirmed by numerical simulations and experimental tests showing additional robustness features. [ABSTRACT FROM AUTHOR]

Most studies on linear system control in the presence of actuator saturation have focused on closed-loop asymptotic stabilisation. Available tracking results are generally limited to constraint-compatible inputs (references, disturbances) with known exogenous input models. The problem of output-reference tracking in the presence of arbitrary-shaped not necessarily constraint-compatible inputs has yet to be investigated. In this study, we show that an tracking performance is achievable for SISO linear systems using a given class of saturated controllers. Accordingly, the tracking error energy (resp. power) is bounded by the energy (resp. power) of a well-defined mismatch input depending on the disturbance and reference compatibility. In the disturbance-free case, this entails perfect asymptotic tracking of arbitrary-shaped constraint-compatible reference signals. Otherwise, the average tracking quality is proportional to the mismatch input power. In the case of periodic inputs (constraint-compatible or not), all system signals are shown to be periodic with the same period as the inputs. [ABSTRACT FROM PUBLISHER]