Adaptive Control of Fuel Cell Converter Based on a New Hamiltonian Energy Function for Stabilizing the DC Bus in DC Microgrid Applications

Abstract

DC microgrid applications include electric vehicle systems, shipboard power systems, and More Electric Aircraft (MEA), which produce power at a low voltage level. Rapid developments in hydrogen fuel cell (FC) energy have extended the applications of multi-phase parallel interleaved step-up converters in stabilizing DC bus voltage. The cascade architecture of power converters in DC microgrids may lead to large oscillation and even risks of instability given that the load converters considered as loads feature constant power load (CPL) characteristics. In this article, the output DC bus voltage stabilization and the current sharing of a multi-phase parallel interleaved FC boost converter is presented. The extended Port-Hamiltonian (pH) form has been proposed with the robust controller by adding an integrator action based on the Lyapunov−Energy function, named “Adaptive Hamiltonian PI controller”. The stability and robustness of the designed controller have been estimated by using Mathematica and Matlab/Simulink environments and successfully authenticated by performing experimental results in the laboratory. The results have been obtained using a 2.5 kW prototype FC converter (by two-phase parallel interleaved boost converters) with a dSPACE MicroLabBox platform. The FC main source system is based on a fuel reformer engine that transforms fuel methanol and water into hydrogen gas H2 to a polymer electrolyte membrane FC stack (50 V, 2.5 kW).

Grid Frequency and Amplitude Control Using DFIG Wind Turbines in a Smart Grid

“…The extensive use of power generation using wind has forced countries to establish a set of rules for the operation and connection to the grid of wind generators. Amongst all the standards, those related to smart networks aim to guarantee a safe supply, and ensure the reliability and quality of the energy generated [25,26]. With the strong growth of grid-connected wind power plants, there is a need for grid-integrated wind farms with the ability to withstand grid voltage and frequency also during perturbations in the network [18].…”

Improved Adaptive Hamiltonian Control Law for Constant Power Load Stability Issue in DC Microgrid: Case Study for Multiphase Interleaved Fuel Cell Boost Converter

“…On the other hand, increasing the power level immediately leads to a protective shutdown of the system. As presented in [8], the dynamic behavior of CPLs is comparable to increment negative impedance, which, under certain conditions, can introduce large oscillations o dangerous instability in the DC distribution. Stability issues should be considered improve the performance of a DC bus.…”

“…Among these nonlinear control schemes, the interconnection and dampin assignment passivity-based control (IDA-PBC, or the Hamiltonian Lyapunov control) ha also received attention in the last decade to address the CPL instability issue [17,18]. Th As presented in [8], the dynamic behavior of CPLs is comparable to incremental negative impedance, which, under certain conditions, can introduce large oscillations or dangerous instability in the DC distribution. Stability issues should be considered to improve the performance of a DC bus.…”

High-Performance Tracking for Proton Exchange Membrane Fuel Cell System PEMFC Using Model Predictive Control

“…A proton exchange membrane fuel cell (PEMFC), which uses hydrogen as the main fuel, has recently attracted great attention due to its cleanliness, high efficiency, high power density and quiet operation [3]. It can be used for a wide range of applications, including automotive, stationary and portable power supplies [4][5][6][7]. For most of those applications, the PEMFC is usually used in conjunction with a DC-DC power converter that generates highly regulated DC voltage for end-use.…”