Stefania Cuoghi

Dr. Stefania Cuoghi

University of Bologna, Bologna, Emilia-Romagna, Italy

Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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24 January 2023 in IEEE Transactions on Control Systems Technology
Verified
Journal Article
Open access
LNLorenzo Ntogramatzidis
Lorenzo Ntogramatzidis
Stefania CuoghiStefania Cuoghi
Stefania Cuoghi
Mattia RiccoMattia Ricco
Mattia Ricco
Riccardo MandrioliRiccardo Mandrioli
Riccardo Mandrioli
Gabriele GrandiGabriele Grandi
Gabriele Grandi
This brief proposes a new multiple input multiple output (MIMO) control for off-board electric vehicle (EV) dc fast chargers. The proposed feedback matrix design avoids multiple tuning of controllers in multiple and interconnected loops while improving the performance of interleaved dc buck converters over classical PI/PID controls. The innovative features of the presented strategy are the reference current monotonic tracking from any initial state of charge with an arbitrarily fast settling time and the fast compensation of both load variations and imbalances among the legs. Numerical results validate the performance improvements of the proposed discrete-time MIMO algorithm for interleaved buck converters over classical PI/PID controls. Full-scale hardware-in-the-loop (HIL) and scaled-down prototype experimental results prove the feasibility and effectiveness of the proposal.

21 May 2024 in IET Power Electronics
Verified
Journal Article
Open access
PDF file
Stefania CuoghiStefania Cuoghi
Stefania Cuoghi
Lohith Kumar PittalaLohith Kumar Pittala
Lohith Kumar Pittala
Riccardo MandrioliRiccardo Mandrioli
Riccardo Mandrioli
Vincenzo CirimeleVincenzo Cirimele
Vincenzo Cirimele
Mattia RiccoMattia Ricco
Mattia Ricco
Gabriele GrandiGabriele Grandi
Gabriele Grandi
This paper presents the discrete‐time modelling and control of modular input‐parallel–output‐parallel (IPOP) dual‐active‐bridge (DAB) converters for electric vehicle (EV) charging. The proposed adaptive control system ensures adequate current‐sharing among parallel modules while minimizing DAB current stress by adopting dual phase‐shift modulation. Driven by the growing need for fast EV charging options, the paper highlights the importance of achieving top‐notch control performance, especially with varying load conditions. Specifically, it introduces a discrete‐time model for adjusting controller parameters adaptively, which simplifies the typically cumbersome manual tuning process associated with these systems. The proposed PI formulae are derived to satisfy specifications on the frequency domain as phase margin and the gain crossover frequency of the open loop gain transfer function, ensuring stability and robustness in operation. Moreover, the implementation of these formulae in discrete microcontrollers facilitates seamless PI autotuning for precise current, voltage, or power control. Notably, the proposed control strategy effectively mitigates current overshot issues commonly encountered during module engagement and shedding operations in modular EV chargers. To validate its efficacy, the proposed controller is evaluated through extensive testing and comparisons within the PLECS environment, particularly focusing on a two‐module IPOP‐DAB converter scenario, and including comparisons with classical offline model‐based pole placement methodology. Furthermore, real‐time hardware‐in‐the‐loop experiments are conducted to confirm the feasibility and performance of the proposed controller under realistic EV charging profiles.

2 November 2011 in International Journal of Control
Verified
Journal Article
Closed access
Roberto ZanasiRoberto Zanasi
Roberto Zanasi
Stefania CuoghiStefania Cuoghi
Stefania Cuoghi
LNLorenzo Ntogramatzidis
Lorenzo Ntogramatzidis
In this article an approach based on inversion formulae is used for the design of lead–lag compensators which satisfy frequency domain specifications on phase margin, gain margin and phase (or gain) crossover frequency. An analytical and graphical procedure for the compensator design on the Nyquist and Nichols planes is presented with some numerical examples.

1 December 2013 in IET Control Theory & Applications
Verified
Journal Article
Open access
PDF file
Stefania CuoghiStefania Cuoghi
Stefania Cuoghi
LNLorenzo Ntogramatzidis
Lorenzo Ntogramatzidis
This study presents a new set of formulae for the design of discrete proportional–integral–derivative (PID) controllers under requirements on steady‐state performance and robustness specifications, such as phase and the gain margins, as well as the gain crossover frequency. The proposed technique has the advantage of avoiding trial‐and‐error procedures or approximations connected to an a posteriori discretisation. This method can also be implemented as a graphical design procedure in the Nyquist plane. The plot of suitable regions can be used to check a priori if the problem leads to feasible values of the PID parameters.

21 March 2022 in Energies
Verified
Journal Article
Open access
PDF file
Stefania CuoghiStefania Cuoghi
Stefania Cuoghi
Riccardo MandrioliRiccardo Mandrioli
Riccardo Mandrioli
Lohith Kumar PittalaLohith Kumar Pittala
Lohith Kumar Pittala
Vincenzo CirimeleVincenzo Cirimele
Vincenzo Cirimele
Mattia RiccoMattia Ricco
Mattia Ricco
This article proposes a dual-active-bridge control to support the fast synthetic inertial action in DC microgrids. First of all, the selection of the isolated DC/DC converter to link an energy storage system with the DC bus in a microgrid is analyzed and the advantages of the dual-active-bridge converter controlled by a single-phase shift modulation justify its selection. An active front-end can be then adapted to connect the DC bus with an AC grid. Secondly, this paper presents the design of a discrete PI controller for supporting fast synthetic inertial action. In particular, a discrete dual-active-bridge model based on the transferred power between both converter bridges, which overcomes the approximations of the output current linearization model, is proposed. Moreover, the article introduces a novel equation set to directly and dynamically tune discrete PI parameters to fulfill the design frequency specifications based on the inversion formulae method. In this way, during the voltage/power transients on the DC bus, the controller actively responds and recovers those transients within a grid fundamental cycle. Since the developed set of control equations is very simple, it can be easily implemented by a discrete control algorithm, avoiding the use of offline trial and error procedures which may lead to system instability under large load variations. Finally, the proposed control system is evaluated and validated in PLECS simulations and hardware-in-the-loop tests.

1 November 2011
Verified
Conference Paper
Closed access
Roberto ZanasiRoberto Zanasi
Roberto Zanasi
Stefania CuoghiStefania Cuoghi
Stefania Cuoghi
In this paper direct methods for the synthesis of continuous and discrete PID compensators for a robust control are proposed. Analytical and graphical techniques on the Nyquist plane to meet specifications on phase margin, gain margin and crossover frequency of the close-loop system are presented. Numerical examples demonstrate the effectiveness and the simplicity of the proposed approach, that can be useful both on educational and industrial applications.