Search

A decentralized control approach is introduced in this paper that utilizes passivity-based control for two DC-distributed energy sources supplying the power of a load. Considering the concept of passivity, if each distributed generator exhibits passivity, this property will be maintained when these generators are connected in series or parallel. Thus, the stability of the entire system is guaranteed through the implementation of an interconnection and damping assignment passivity-based control (IDA-PBC). Additionally, droop voltage control is employed to achieve current sharing among the two power sources. If the model used is not an accurate representation of the original system, the controlled system may experience steady-state errors. To address these modeling errors, a compensation term is employed as the desired output voltage. The effectiveness of the proposed methodology is confirmed via results from simulation in three cases in which the performance of the system is investigated in start-up and load resistance or nominal load current change. With PBC, the system maintains stable operation. Experimental results validate the simulation results. Moreover, the proposed method guarantees global stability without knowing the parameters to prove global stability with local control.

The main objective in microgrids is keeping their frequency and voltage close to the rated values, and ensuring a precise power sharing of their distributed generators (DGs). This can be challenging in a meshed microgrid due to the tight coupling between active and reactive power resulting from its various power line impedances. Centralized control strategies are widely used to address these issues. But, the increase in DGs number in meshed microgrids rises the communication system cost due to the high number of data to be acquired and processed. Most of existing distributed control strategies in literature are unable to treat simultaneously power sharing as well as voltage and frequency restoration. In this paper a distributed consensus-based control is proposed for accurate active and reactive power sharing as well as frequency and voltage restoration in meshed reconfigurable islanded microgrids. The controllers for primary and secondary control are locally adjusted and do not require knowledge of the microgrid structure. The efficiency of the proposed strategies is verified with large load variations, microgrid topology change and various communication delays by simulation and validated by real-time Hardware in The Loop tests.

To deal with the intermittency of renewable energy resources, hydrogen as an energy carrier is a good solution. The Polymer Electrolyte Membrane Fuel Cell (PEMFC) as a device that can directly convert hydrogen energy to electricity is an important part of this solution. However, durability and cost are two hurdles that must be overcome to enable the mass deployment of the technology. In this paper, a management system is proposed for the fuel cells that can cope with the durability issue by a suitable distribution of electrical power between cell groups. The proposed power electronics architecture is studied in this paper. A dynamical average model is developed for the proposed system. The validation of the model is verified by simulation and experimental results. Then, this model is used to prove the stability and robustness of the control method. Finally, the energy management system is assessed experimentally in three different conditions. The experimental results validate the effectiveness of the proposed topology for developing a management system with which the instability of cells can be confronted. The experimental results verify that the system can supply the load profile even during the degradation mode of one stack and while trying to cure it.

If the birth of comic strips is accompanied by a theorical effort through the work of a Töpffer seeking to circumscribe all possible available to them, it is clear that the vein will soon dry up. Quickly removed from the critical field, the comic seems to benefit from any serious analysis that could help authors and readers in their practises. Through History, Comics has worked empirically it its substance, sometimes with genius (McCay, Hergé ...) often soulless, with the exception of some attempts that this article intends to present.