The growing need to decarbonize the transport sector has accelerated the development of sustainable alternatives to fossil fuels such as hydrogen-powered electric vehicles. In this context, power electronics converters are essential for efficient energy transfer and power flow management of Fuel Cell systems. This paper presents an innovative DC/DC converter architecture, referred to as the "Parallel-Cascade", that addresses the modularity and scalability demands of Multi-Stack Fuel Cell systems in Heavy-Duty applications. The proposed converter architecture is compared to conventional Multi-Stack configurations, using key performance indicators such as power losses, components stress factors, stored energy, and relevant qualitative criteria. Simulation results are provided under both normal and faulty operating conditions, highlighting the reconfiguration capability of the proposed control scheme. Prototype design and preliminary experimental validation are also presented.

We introduce an innovative harmonic-model-based control strategy tailored for a three-phase AC-DC converter. Our method involves a nonlinear harmonic domain model, which proves highly effective in formulating harmonic control laws with a global stability guarantee. This framework not only accommodates control objectives associated with harmonic distortion but also facilitates the precise tracking of periodic trajectories. Experimental results are presented to showcase the methodology’s effectiveness in reducing Total Harmonic Distortion (THD), thereby validating the successful accomplishment of the targeted control objectives.

This article presents an improved Hamiltonian control law (HCL) with load current sensorless ability for multiphase parallel converters in electric vehicle applications. On one hand, the proposed control approach has a significant advantage in handling constant power load (CPL) that occurs in the situation of the vehicle, which is a dangerous situation that can cause oscillations and uncertainty. On the other hand, the load current observer is applied with HCL to improve the efficiency and reliability of the converter system. In addition, by eliminating the need for current sensors, the cost and size of the converter system are reduced, while maintaining accurate current control. Moreover, the difference flatness approach has been applied to generate the current reference resulting in regulating the DC bus voltage. Finally, the multiphase two-quadrant converter driving by the proposed control law has been evaluated through experimental tests. The obtained experimental results demonstrate the excellent performance of the multiphase two-quadrant converter with CPL thereby confirming the efficacy of the proposed approach.

The present paper aims to propose a real-time energy management strategy (EMS) based on two-phase interleaved buck-boost and boost converters for Fuel Cell/supercapacitor hybrid system. The interleaved converter (IC) is chosen to be applied in this work thanks to advantages, which presents compared to conventional DC/DC converter, as low input current ripples, a higher efficiency, a faster transient response, a reduced electromagnetic emission and an improved reliability. The proposed converters control strategies continuously support the EMS, based on frequency distribution to coordinate the hybrid power supply system, under variable load power conditions. In order to implement the proposed controllers, a laboratory test bench is applied to conduct experimental validation of the adopted structure. Experiments FC/SC hybrid system with the developed EMS was performed for variable load and the experiment waveforms of each power source are included. The obtained results suggest that the proposed energy management algorithm and the converters controllers present good performances.

Current source rectifier (CSR) tends to be attractive in industrial applications where a voltage step down function is required. It is used in different industrial applications such as: uninterruptible power supply (UPS), front-end rectifier for data center power supply, on-board charger of electric vehicle, motor drive application, electrolyzer application etc. In this paper, an average model based on the current reference vectors is proposed: it allows to determine quickly the dynamics because it doesn't require the space vector modulation part, and is weakly dependent of the topology. This model allows to set up a control strategy using two loops. The internal loop with high bandwidth will be based on flatness properties which allows to naturally damps the grid current oscillations without active damping methods. The external loop based on an energy balance will be discussed. A stability analysis will be presented. Finally, simulation and experimental results will verify the effectiveness of the proposed solution.

In more electrical aircraft, the embedded electrical network is handling more and more vital functions, being more and more strained as well. Attenuation of switching harmonics is a key step in the network reliability, thus filtering elements play a central role. To keep the weight of the embedded network reasonable, weakly damped high-order filters shall be preferred. Flatness-based control (FBC) can offer both high bandwidth regulation and large signal stability proof. This make FBC a good candidate to handle the inherent oscillating behavior of aforementioned filters. However, this control strategy can be tricky to implement, especially with high order systems. Moreover, FBC is more sensor demanding than classic PI-based control. This paper address these two drawbacks. First, a novel trajectory planning for high order systems is proposed. This method does not require multiple derivations. Then the input sensors are removed thanks to a parameters estimator. Feasibility and performances are verified with experimental results. Performances comparison with cascaded-loop topologies are given in final section to prove the relevance of the proposed control strategy.

Nowadays distribution power systems are used in different applications such as aircraft, ships, submarines and hybrid electric vehicles. However, the interaction between individually designed power subsystems may cause instability. Moreover, in these applications, the constant power load (CPL) also poses challenges for system dynamic response and stability. Thus, the main objective is to stabilize the cascaded system supplying the CPL. An interconnection and damping assignment (IDA) passivity-based control (PBC) scheme for LC filter cascaded with buck converter supplying CPL is proposed. The plant is described by port-controlled Hamiltonian (PCH) form. Particularly, an adaptive interconnection matrix is developed to achieve internal links in PCH system. A modified IDA-PBC and its proof are presented to perfect the implementation for the CPL application. Simulation results are given to illustrate the effectiveness of the proposed approach.

It is well know that the interaction between poorly damped LC input filter with dc-dc converter lead to degradation of dynamic performance and fault scenario of the system. This problem also often occurs in fuel cell systems. Due to the relatively low and unregulated output voltage, the high gain boost converter is need in such application. A floating interleaved boost converter (FIBC) is selected as a good candidate to achieve this desired effect. In order to ensure the system stability, this paper addresses a method which permits to design a fault-tolerant stabilizing system for the proposed converter and the filter. It consists in implementing an active stabilizer for each switch. Afterward, a method to design fault-tolerant stabilizing system is developed. The simulation results are reported to verify the effectiveness of the proposed method.

It is well known that the Conventional Droop method is commonly used to share real and reactive power between distributed Generation interfaced converters (DICs) based Islanded microgrid. The share of power is done autonomously without communication between Converters. Despite the lot of desirable features the Droop method had, there exist some limitations concerning the accuracy of the reactive power shared between converters when line impedance mismatches exist. This paper presents the droop control law for islanded microgrid, and proposes an online state estimation of the point of common coupling (PCC) voltage, which is then used as a feedback signal for the Droop control to accurately share the power between parallel converters. Thus the proposed method keeps the advantages of the Droop control method to manage the power between distributed generations in autonomous fashion without additional communication links.

Power electronic converters and electric motor drives have become common loads in advanced power systems. Passive LC filters are often used in these systems to reduce the DC-link ripples. These filters are poorly damped for reducing the power losses as well as the size, weight and cost of the system. This may lead to instability phenomena if the load is tightly controlled and absorbs a power exceeding a limit depending on the filter parameters. The purpose of this paper is to present an input impedance shaping method to stabilize DC-link. A matrix filter is put in cascade with load's current controllers. The filter is designed to shape properly input impedance of the load while keeping its performances. Small signal stability of the DC power system is proved using this method. Simulation and experimental results confirm the effectiveness of the proposed stabilizer.

Based on the properties of flatness system, this paper proposes a nonlinear control for a dual active bridge converter for fuel cell applications. This converter is connected to fuel cell via a diode and an LC low-pass filter. The constraint of fuel cell like the maximum power and current slope are taken into account by means of the control of the energy stored in the filter capacitor corresponding to the fuel cell voltage obtained from its static characteristic. The diode and parasitic resistances are modeled as a series resistance connected to the fuel cell and its value is estimated and is used in the control algorithm. The effectiveness of the proposed system is demonstrated via experimental results.

This paper proposes a nonlinear control for a dual active bridge converter (DAB) using properties of flatness system. This converter system is used for a DC microgrid. Losses in the system are modeled as a resistance connected in parallel with the output capacitor. The control algorithm also takes this resistance into account. With a small-scale test bench, bidirectional power flow capability is demonstrated. The effectiveness of the proposed system is demonstrated through experimental results.

In this paper, a global optimal study of the efficiency of a cascaded structure with synchronous rectification composed of two sub-converters has been presented, this converter allows obtaining high voltage ratio and consists of two-interleaved boost converter which was chosen as 1stsub-converter and three-level boost converter which was chosen as 2ndsub-converter. An optimal efficiency operation as a function of the intermediate voltage and the branch number of the first converter is studied by the aid of an adaptive losses estimation algorithm to estimate the components losses for each DC/DC converter. The estimated power losses of the two converters are modeled by two estimated resistances. These estimated resistances are used to study and optimize the relation between the intermediate voltage and the global efficiency and also the influence of the number of branches of the interleaved converter on the total global losses. The algorithm is theoretically analyzed, developed and compared with the experimental results. Experimental results allow validating the proposed analysis for maximizing global efficiency.