Hydrogen electrolyzers, with their operational flexibility, can be configured as smart dynamic loads which can provide grid services and facilitate the integration of more renewable energy sources into the electrical grid. However, to enable this ability, the electrolyzer system should be able to control both active and reactive power in coordination with the low-level controller of the electrolyzer via the power electronics system interface between the utility grid and electrolyzer. This paper discusses power converter topologies and the control scheme of this power electronics interface for electrolyzer applications to enable electricity grid services. For the sake of unity, in this paper, we consider the power converter system interfacing the utility grid at the line-to-line root mean square RMS value of 480 VAC 60 Hz and supplying to the 3500 A 750 kW PEM electrolyzer stack.
This paper presents the operation modes and control architecture of the grid-connected hydrogen electrolyzer systems for the provision of frequency and voltage supports. The analysis is focused on the primary and secondary loops in the hierarchical control scheme. At the power converter inner control loop, the voltage- and current-control modes are analyzed. At the primary level, the droop and opposite droop control strategies to provide voltage and frequency support are described. Coordination between primary control and secondary, tertiary reserves is discussed. The case studies and real-tim…
Model-Free Detection and Accommodation of Sensor Faults for a PEM Electrolyzer
Université de Lorraine（洛林大学）；Research Center for Automatic Control of Nancy (CRAN), UMR CNRS 7039, Université de Lorraine（南西自动控制中心 (CRAN)）；Laboratoire Jacques-Louis Lions (LJLL), UMR CNRS 7598, Sorbonne Université（雅克-路易·利昂斯实验室 (LJLL)）
Rapid charger is getting more and more important as the electric vehicle (EV) getting popular. The rapid charging technique plays an important part in the electric vehicle development. Multiport converter is used in the rapid charging technique to reduce the required current and also provides some other advantages. In this paper, the literature review form multiport converter to the rapid charger of electric vehicle is introduced. Some topologies of multiport converter are discussed in the literature review. Triple active bridge topology (TAB) is selected as it is useful and commonly used. The…
Partial resonance high frequency AC link converters are recognized to provide soft-switching, single-stage power conversion. They are highly reliable due to elimination of DC capacitors. Previous work has focused on proof of concept topologies and design requirements. In this work, a current regulated AC-DC converter from this family of converters is presented. The control design and grid integration requirements are discussed. An active damping method using grid current feedback is implemented to mitigate the filter resonance oscillations. The current control is implemented in the synchronous…
AC transmission lines with lengths greater than 80km cannot be used to their maximum capacity due to limits in voltage drops and transient stability. This inefficient way of using conductors in a transmission line can be overcome if the electrical frequency at which energy is transmitted is reduced. This is why this work focuses on the comparison of the Modular Multilevel Matrix Converter (MMMC) and the Back-to-Back Modular Multilevel Converter (BTB-MMC), topologies that have shown qualities as frequency converters. For comparison, an analytical model of each topology is used to relate design …
In this paper, a novel model-free wide-area damping control (WADC) method is proposed, which can achieve full decoupling of modes and damp multiple critical inter-area oscillations simultaneously using grid-connected voltage source converters (VSCs). The proposed method is purely measurement based and requires no knowledge of the network topology and the dynamic model parameters. Hence, the designed controller using VSCs can update the control signals online as the system operating condition varies. Numerical studies in the modified IEEE 68-bus system with grid-connected VSCs show that the pro…
DC Link Capacitor Ripple Constraints Limit the Benefits of Utility-Owned Four-Wire Power Converters
School of Engineering, Newcastle University（纽卡斯尔大学工程学院）；School of Electrical Engineering and Computer Science, University of Queensland（昆士兰大学电气与计算机工程学院）
Cascaded H-bridge and modular multilevel converters (MMC) are on the rise with emerging applications in renewable energy generation, energy storage, and electric motor drives. However, their well-known advantages come at the price of complicated balancing, high-bandwidth isolated monitoring, and numerous sensors that can prevent MMCs from expanding into highly cost driven markets. Therefore, an obvious trend in research is developing control and topologies that depend less on measurements and benefit from simpler control. Diode-clamped topologies are considered among the more applicable soluti…
The series-paralleling technique of dc-dc converters is utilized in various domains of electrical engineering for improved power conversion. Previous studies have proposed and classified the control schemes for the series-paralleled converters. However, they have several restrictions and lack diversity. The purpose of this paper is to propose passivity-based control (PBC) for the diverse output series-parallel connection of dc-dc converters. It is proved that the output series-paralleled converters regulated by PBC are asymptotically stable. The output series-paralleled converters are numerica…
This paper investigates the performance limits of differential power processing (DPP) and presents quantitative and systematic design guidelines for the selection and comparison of DPP topologies. A stochastic model is developed to evaluate the expected power losses of a variety of DPP topologies with probabilistic load distribution. The expected losses of several DPP topologies are derived and compared against traditional dc-dc converters to reveal their performance limits. The impacts of the load distribution and load scale on the expected losses are investigated. The theoretical models are …
The design of gate drivers is an important topic in power converter topologies that can help reduce switching losses and increase power density. Gate driving techniques that offer zero-voltage switching and/or zero current switching have recently been successfully proposed for different modular multilevel converters such as the cascaded H bridge. Previous papers on other multilevel converters such as the multi-active bridge, however, do not sufficiently assess the topics of gate driver design for this topology. This work presents a novel isolated gate driver architecture tailored to the multi-…
The paper establishes a methodology to overcome the difficulty of dynamic frame alignment and system separation in impedance modeling of ac grids, and thereby enables impedance-based whole-system modeling of generator-converter composite power systems. The methodology is based on a frame-dynamics-embedding transformation via an intermediary steady frame between local and global frames, which yields a locally defined impedance model for each generator or converter that does not rely on a global frame but retains all frame dynamics. The individual impedance model can then be readily combined int…
In this paper, a new fault tolerant dc-ac converter-fed induction motor drive is proposed to maintain motor as close as possible to its desired normal operation under open- and short-circuit switch failures. The operational principles for fault detection and isolation schemes are provided. Two control strategies including predictive control and voltage mode-controlled PWM with integral-double-lead controller for two stage of the converter are presented in conjunction with the elaborated discussion. The control strategy determines appropriate switching states for continuous operation of the dri…
A charging system is required to convert ac electricity from the grid to dc electricity to charge an electric vehicle (EV) battery. According to the Society of Automatic Engineers (SAE) standard, EV chargers can be divided into three levels based on power rating: Level 1, Level 2, and Level 3. This paper investigates the circuit topologies and control principles of EV charging systems at each level. Three high-fidelity testbeds of EV charging systems for a 10 kWh battery are designed and implemented in real-time digital simulator RT-Lab. The testbeds include modeling details such as switching …
Solar micro-inverters are becoming increasingly popular as they are modular, and they posses the capability of extracting maximum available power from the individual photovoltaic (PV) modules of a solar array. For realizing micro-inverters single stage transformer-less topologies are preferred as they offer better power evacuation efficacy. A SEPIC-Ćuk based transformer-less micro-inverter, having only one high frequency switch and four line frequency switches, is proposed in this paper. The proposed converter can be employed to interface a 35 V PV module to a 220 V single phase ac grid. As a …
Micro- and smart grids (MSG) play an important role both for integrating renewable energy sources in conventional electricity grids and for providing power supply in remote areas. Modern MSGs are largely driven by power electronic converters due to their high efficiency and flexibility. Nevertheless, controlling MSGs is a challenging task due to highest requirements on energy availability, safety and voltage quality within a wide range of different MSG topologies. This results in a high demand for comprehensive testing of new control concepts during their development phase and comparisons with…
This critical analysis offers a comprehensive overview of the efficiency and noise reduction methodologies applied in switch mode power supplies (SMPSs) and the emerging trends in the field. The study acknowledges that power supplies are an essential element in most electronic devices, and the recent developments have placed a greater emphasis on precision, miniaturization, and effectiveness of these components. The research focuses on SMPSs in comparison with other power supply methodologies and investigates the identification and mitigation of internal and external noise in DC Buck converter…
Electric Vehicles (EVs) are projected to be one of the major contributors to energy transition in the global transportation due to their rapid expansion. The EVs will play a vital role in achieving a sustainable transportation system by reducing fossil fuel dependency and greenhouse gas (GHG) emissions. However, high level of EVs integration into the distribution grid has introduced many challenges for the power grid operation, safety, and network planning due to the increase in load demand, power quality impacts and power losses. An increasing fleet of electric mobility requires the advanced …
