Visible to the public Biblio

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2021-03-22
Hosseinipour, A., Hojabri, H..  2020.  Small-Signal Stability Analysis and Active Damping Control of DC Microgrids Integrated With Distributed Electric Springs. IEEE Transactions on Smart Grid. 11:3737–3747.
Series DC electric springs (DCESs) are a state-of-the-art demand-side management (DSM) technology with the capability to reduce energy storage requirements of DC microgrids by manipulating the power of non-critical loads (NCLs). As the stability of DC microgrids is highly prone to dynamic interactions between the system active and passive components, this study intends to conduct a comprehensive small-signal stability analysis of a community DC microgrid integrated with distributed DCESs considering the effect of destabilizing constant power loads (CPLs). For this purpose, after deriving the small-signal model of a DCES-integrated microgrid, the sensitivity of the system dominant frequency modes to variations of various physical and control parameters is evaluated by means of eigenvalue analysis. Next, an active damping control method based on virtual RC parallel impedance is proposed for series DCESs to compensate for their slow dynamic response and to provide a dynamic stabilization function within the microgrid. Furthermore, impedance-based stability analysis is utilized to study the DC microgrid expandability in terms of integration with multiple DCESs. Finally, several case studies are presented to verify analytical findings of the paper and to evaluate the dynamic performance of the DC microgrid.
2020-07-03
Xu, Yonggan, Luo, Jian, Tang, Kunming, Jiang, Jie, Gou, Xin, Shi, Jiawei, Lu, Bingwen.  2019.  Control Strategy Analysis of Grid-connected Energy Storage Converter Based on Harmonic Decomposition. 2019 IEEE Innovative Smart Grid Technologies - Asia (ISGT Asia). :1324—1329.

The three-phase grid-connected converter control strategy, which applies to the battery energy storage system, generally ignores the interference of harmonic components in the grid voltage. As a result, it is difficult to meet the practical application requirements. To deal with this problem, it is necessary to optimize and improve the traditional control strategy, taking harmonics into consideration. And its bases are analysis of the harmonic characteristics and study of its control mechanism in the grid-connected converter. This paper proposes a method of harmonic decomposition, classifies the grid voltage harmonics and explores the control mechanism in the grid-connected converter. With the help of the simulation model built by Matlab/Simulink, the comparative simulation of the energy storage control system carried out under the control of the ideal grid voltage input and the actual one, verifies the correctness of the analytical method proposed in the article.

2020-04-24
M'zoughi, Fares, Garrido, Aitor J., Garrido, Izaskun, Bouallègue, Soufiene, Ayadi, Mounir.  2018.  Sliding Mode Rotational Speed Control of an Oscillating Water Column-based Wave Generation Power Plants. 2018 International Symposium on Power Electronics, Electrical Drives, Automation and Motion (SPEEDAM). :1263—1270.

This paper deals with the modeling and control of the NEREIDA wave generation power plant installed in Mutriku, Spain. This kind of Oscillating Water Column (OWC) plants usually employ a Wells turbine coupled to a Doubly Fed Induction Generator (DFIG). The stalling behavior of the Wells turbine limits the generated power. In this context, a sliding mode rotational speed control is proposed to help avoiding this phenomenon. This will regulate the speed by means of the Rotor Side Converter (RSC) of the Back-to-Back converter governing the generator. The results of the comparative study show that the proposed control provides a higher generated power compared to the uncontrolled case.

Bellec, Q., le Claire, J.C., Benkhoris, M.F., Coulibaly, P..  2019.  Investigation of time delay effects on the current in a power converter regulated by Phase-Shift Self-Oscillating Current Controller. 2019 21st European Conference on Power Electronics and Applications (EPE '19 ECCE Europe). :P.1–P.10.

This paper deals with effects of current sensor bandwidth and time delays in a system controlled by a Phase-Shift Self-Oscillating Current Controller (PSSOCC). The robustness of this current controller has been proved in former works showing its good performances in a large range of applications including AC/DC and DC/AC converters, power factor correction, active filters, isolation amplifiers and motor control. As switching frequencies can be upper than 30kHz, time delays and bandwidth limitations cannot be neglected in comparison with former works on this robust current controller. Thus, several models are proposed in this paper to analyze system behaviours. Those models permit to find analytical expressions binding maximum oscillation frequency with time delay and/or additional filter parameters. Through current spectrums analysis, quality of analytical expressions is proved for each model presented in this work. An experimental approach shows that every element of the electronic board having a low-pass effect or delaying command signals need to be included in the model in order to have a perfect match between calculations, simulations and practical results.

2020-03-27
Richter, Michael, Mehlmann, Gert, Luther, Matthias.  2019.  Grid Code Compliant Modeling and Control of Modular Multilevel Converters during Unbalanced Faults. 2019 54th International Universities Power Engineering Conference (UPEC). :1–6.

This paper presents necessary modeling and control enhancements for Modular Multilevel Converters (MMC) to provide Fault-Ride-Through capability and fast fault current injection as required by the new German Technical Connection Rules for HVDC. HVDC converters have to be able to detect and control the grid voltage and grid currents accurately during all fault conditions. That applies to the positive as well as negative sequence components, hence a Decoupled Double Synchronous Reference Frame - Phase-Locked-Loop (DDSRF-PLL) and Current Control (DDSRF-CC) are implemented. In addition, an enhanced current limitation and an extension of the horizontal balancing control are proposed to complement the control structure for safe operation.

2020-01-20
Ajaei, F. Badrkhani, Mohammadi, J., Stevens, G., Akhavan, E..  2019.  Hybrid AC/DC Microgrid Configurations for a Net-Zero Energy Community. 2019 IEEE/IAS 55th Industrial and Commercial Power Systems Technical Conference (I CPS). :1–7.

The hybrid microgrid is attracting great attention in recent years as it combines the main advantages of the alternating current (AC) and direct current (DC) microgrids. It is one of the best candidates to support a net-zero energy community. Thus, this paper investigates and compares different hybrid AC/DC microgrid configurations that are suitable for a net-zero energy community. Four different configurations are compared with each other in terms of their impacts on the overall system reliability, expandability, load shedding requirements, power sharing issues, net-zero energy capability, number of the required interface converters, and the requirement of costly medium-voltage components. The results of the investigations indicate that the best results are achieved when each building is enabled to supply its critical loads using an independent AC microgrid that is interfaced to the DC microgrid through a dedicated interface converter.

2019-02-14
Zhao, Z., Lu, W., Ma, J., Li, S., Zhou, L..  2018.  Fast Unloading Transient Recovery of Buck Converters Using Series-Inductor Auxiliary Circuit Based Sequence Switching Control. 2018 IEEE International Power Electronics and Application Conference and Exposition (PEAC). :1-5.

This paper presents a sequence switching control (SSC) scheme for buck converters with a series-inductor auxiliary circuit, aiming at improving the load transient response. During an unloading transient, the series inductor is controlled as a small equivalent inductance so as to achieve a fast transient regulation. While in the steady state, the series inductor behaves as a large inductance to reduce the output current ripple. Furthermore, on the basis of the proposed variable inductance circuit, a SSC control scheme is proposed and implemented in a digital form. With the proposed control scheme the unloading transient event is divided into n+1 sub-periods, and in each sub-period, the capacitor-charge balance principle is used to determine the switching time sequence. Furthermore, its feasibility is validated in experiment with a 12V-3.3V low-voltage high-current synchronous buck converter. Experimental results demonstrate that the voltage overshoot of the proposed SSC scheme has improved more than 74% compared to that of the time-optimal control (TOC) scheme.