In this paper the problem of multi-source power sharing strategy within electric vehicles is considered. Three different kinds of power sources-fuel cell, battery and supercapacitor-compose the power supply system, where all sources are current-controlled and paralleled together with their associated DC-DC converters on a common DC-link. The DC-link voltage must be regulated regardless of load variations corresponding to the driving cycle. The proposed strategy is a robust control solution using a MIMO LPV/H∞ controller which provides the three current references with respect to source frequency characteristics. The selection of the weighting functions is guided by a genetic algorithm whose optimization criterion expresses the frequency separation requirements. A reduced-order version of the LPV/H∞ controller is also proposed to handle an embedded implementation with limited computational burden. The nonlinear multi-source system is simulated in MATLAB R /Simulink R using two different types of driving cycles: the driving cycle of IFSTTAR (Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux) and a constant load profile used in order to illustrate system steady-state behaviour. Simulation results show good performance in supplying the load at constant DC-link voltage according to user-configured frequency-separation power sharing strategy. When assessed against the classical-PI-based filtering strategy taken as base-line, the proposed strategy offers the possibility of integrating a variety of constraints into a systematic design procedure, whose result guarantees stability and performance robustness.

This paper presents an LPV/H∞ control strategy applied to power source coordination on board of averagepower electric vehicles. The proposed approach concerns frequency separation of responses between three power sources in order to satisfy power demand of vehicle's electrical motor, taking into account that sources are expected to work within distinct frequency ranges. The three sources-fuel cell, battery and ultracapacitor-are connected in parallel to a common DC-bus which supplies the electrical motor. The idea is to use the weighting functions associated to the LPV/H∞ controller to determine auxiliary power source behaviors-battery and ultracapacitor-and to minimize the variation of fuel cell current and the DC-bus voltage. As a result, DC-bus voltage is regulated at 150 V, while the fuel cell provides mean power to the electrical motor. MATLAB R /Simulink R numerical simulation is used to validate the proposed approach by using two driving scenarios, namely Normalized European Driving Cycle (NEDC) and the driving cycle proposed by IFSTTAR (Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux).

This paper proposes a modified Perturb and Observe (P&O) Extremum Seeking Control (ESC) technique in presence of multiple maxima. ESC is applied to single-phased gridconnected photovoltaic (PV) arrays which have to provide maximum power irrespective of solar irradiance conditions. In particular, partially shadow conditions may lead to steady-state power curves exhibiting multiple maxima. The power harvested from the PV generator is injected in the single-phased power grid by using two power converter stages: step-up DC-DC converter and DC-AC inverter. When multiple power maxima exist, the amplitude of the perturbation signal plays an important role in successfully tracking the global maximum. Two amplitude modulation strategies are analyzed for the same case study: amplitude modulation by using a first-order-system-response signal and amplitude modulation by using small duty ratio square-wave signal, respectively. MATLAB ® /Simulink ® numerical simulations are presented in order to assess the two approaches comparatively.

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