Reconfigurable Power Research Articles

Novel Reconfigurable Power Converters Facilitating Dual Battery Integration in Electric Vehicles

Novel Reconfigurable Power Converters Facilitating Dual Battery Integration in Electric Vehicles

Solar PV powered DC charger for electric vehicles with reconfigurable power electronic interface

ABSTRACT Global expansion of the EV market has led to widespread DC charging infrastructure. Consumers prefer DC charging over AC to reduce charging time per kilometer. However, grid-connected DC chargers can cause issues such as grid instability, power quality problems, demand imbalance, and conversion losses. This paper proposes an off-grid photovoltaic (PV) fed DC charger for EVs along with a battery energy storage system (BESS) to mitigate these challenges. The work aims to increase the use of clean energy for EV charging, to ensure uninterrupted EV charging with minimum power conversion stages, and to improve PV utilization. BESS serves as a backup power source that charges or discharges based on PV availability. Additionally, the system powers the non-critical adjustable loads of domestic/industrial sites with the available PV power when both EV and BESS are fully charged. The system can be reconfigured to operate in six distinct modes using two DC-DC converters and five relays. Among six modes, four modes operate in single-stage power conversion. A buck converter is used to extract power from PV. A bidirectional buck-boost converter is used to charge and discharge the BESS. The proposed system is validated through hardware prototype for both steady-state and transient conditions.

Reconfigurable power converters with increased utilization for unbalanced power distribution system applications

Reconfigurable power converters with increased utilization for unbalanced power distribution system applications

Design and validation of a miniaturized reconfigurable power divider with arbitrary power split ratio and flexible output phase difference

This study introduces a microstrip line (ML) based reconfigurable 5-port power divider (PD) capable of manipulating power ratios at four output ports. The proposed PD offers two operational modes: unidirectional and bidirectional. In unidirectional transmission mode, the entire source power is directed to a particular output port, while in bidirectional transmission mode, the source power is equally distributed between two output ports. The selection of different transmission modes is accomplished by configuring six adaptive loads that are coupled to the PD structure, and the corresponding S-parameters of the proposed PD are derived by even–odd mode modeling. The resulting data is subsequently optimized by a numerical approach to identify the required design parameters that would ensure optimal performance. The proposed PD resonates at 1.06GHz and covers a frequency range spanning 0.9GHz to 1.2GHz, making it an excellent option for supplying regulated power to multi-port antennas or multiple input multiple output (MIMO) antennas proposed for aircraft navigation applications. The prototype has been developed to validate the notion of reconfigurable reactive loads utilizing varactor diodes and the recorded result is evaluated with the simulated results. The findings confirm excellent performance with regards to insertion loss (with a difference of <-2dB from the optimal values), reflection coefficient (≥-20dB), and isolation (≥-40dB) between the transmitting (input port) and non-transmitting or the remaining ports.

Design of class f reconfigurable power amplifiers

With the rapid development of mobile communication technology, RF amplifier requirements becoming higher, miniaturization, high efficiency and multi-band have gradually become a research hotspot. Based on these hot research directions, this paper designs a dual-band reconfigurable power amplifier. The input of the amplifier adopts a stepped impedance matching network, which has a good matching effect in the 1.6 - 2.8 GHz band. The output is switched by a single-knife double-throw switch to the corresponding band output matching network to achieve the fast switching of different frequency bands. The RF amplifier tube is designed by using Cree’s GaN chip CGH40010F, which has an additional power efficiency of more than 60% in the frequency range of 1.7 - 1.9 GHz and 2.5 - 2.7 GHz bands, a gain of about 12 - 14 dB and a saturated output power of more than 40 dBm. This design has the features of high efficiency, high gain, miniaturization and multi-band, which is applicable to the mobile communication system.

Intelligent wireless power transfer via a 2-bit compact reconfigurable transmissive-metasurface-based router

With the rapid development of the Internet of Things, numerous devices have been deployed in complex environments for environmental monitoring and information transmission, which brings new power supply challenges. Wireless power transfer is a promising solution since it enables power delivery without cables, providing well-behaved flexibility for power supplies. Here we propose a compact wireless power transfer framework. The core components of the proposed framework include a plane-wave feeder and a transmissive 2-bit reconfigurable metasurface-based beam generator, which constitute a reconfigurable power router. The combined profile of the feeder and the beam generator is 0.8 wavelengths. In collaboration with a deep-learning-driven environment sensor, the router enables object detection and localization, and intelligent wireless power transfer to power-consuming targets, especially in dynamic multitarget environments. Experiments also show that the router is capable of simultaneous wireless power and information transfer. Due to the merits of low cost and compact size, the proposed framework may boost the commercialization of metasurface-based wireless power transfer routers.

A design of reconfigurable antenna with wide/narrow beam tunability

In this paper, a reconfigurable multibeam antenna with switchable polarization and wide/narrow beam tunability is presented. The antenna consists of a reconfigurable power splitter and a 2 × 2 patch antenna array. The curved patch, as part of the periphery of the antenna unit, is used to switch grounded and ungrounded, so as to achieve wide and narrow beam radiation, respectively. By embedding p-i-n diodes in the power splitter and switching the ON/OFF state, the selection of the output ports and the phase difference between them are achieved. In the process of function selection, polarization switching can be realized by exciting the antenna units at different positions. Beam deflection can be achieved by controlling the phase difference between output ports. To ensure stable and fast switching between beam states, the antenna is controlled by an external micro-control system, which has the advantages of simplicity, stability, and speed. The experimental results show that the antenna can generate 12 beam states, which are in good agreement with the simulation results.

A compact and reconfigurable C-band DGS-based power divider using RF MEMS capacitive switch

This article presents a reconfigurable and compact power divider design that utilizes a combination of defect structures in the ground plane (DGS) and capacitance loading using a unique RF MEMS switch on the sapphire substrate. The combination of these two techniques results in a reduced-size reconfigurable power divider, wherein the length of the quarter-wavelength transmission line is reduced to λ/16 from λ/4, and the higher-order harmonics are suppressed up to 40 GHz. The RF MEMS capacitive switch is designed, and its DC characteristics are simulated in coventorware. The RF characteristics of the designed power divider are simulated in Ansys HFSS 19.2. The power divider utilizing RF MEMS technology has been fabricated through surface micromachining, requiring only four masks for fabrication. According to measurement findings, insertion loss and return loss are 3.57 dB and 24.6 dB (at 4.4 GHz) and 3.82 dB and 22.06 dB (at 5.4 GHz) when the switch is on and off, respectively. The total area of the design is 3.1 mm2 (21.3% of the conventional power divider). The proposed design can suppress harmonics up to the 8th order by 10 dB. These features render it a viable option for employment in Radio Frequency Integrated Circuits (RFICs).

A fully reconfigurable 1 × 4 power divider with power division reconfiguration and size reduction based on series coupled cascaded transmission lines

This work presents a 1X4 fully reconfigurable power divider with a wide range of power divisions and reduced size, designed for adaptive null forming and beam steering networks in RF front ends. The design is based on the impedance transformation of series-coupled cascaded transmission lines and a reconfigurable isolation network. The impedance of power-dividing arms is transformed by tuning the voltage-dependent equivalent capacitor, controlling insertion loss, and indirectly influencing the power division ratio. Four transmission states with sixteen different power levels are realized. This design approach is validated by fabricating a prototype with four output ports. The measured power division varies from 6.5 dB to 18 dB at the center frequency, and the return loss is greater than -32 dB. Output port isolation is greater than -30 dB, and the phase response at output ports only shows a difference of less than 2 degrees. The power at any output port can be reconfigured independently without affecting the system’s overall performance, achieved through a series-coupled transmission line, contributing to a reduction in size. A size reduction of 37 percent is attained in this design. The proposed power divider can provide a wide range of power levels at all output ports within a narrow band around the center frequency. Hence, the design is suitable for beam steering networks, pattern, and polarization reconfigurable antenna arrays. The design also has extension capability into N-way configurations.

Additively Manufactured Microfluidically Reconfigurable Power Divider

Additively Manufactured Microfluidically Reconfigurable Power Divider

Research and Development of a Two Octaves Reconfigurable Power Amplifier

Research and Development of a Two Octaves Reconfigurable Power Amplifier

Reconfigurable hybrid micro-grid with standardized power module for high performance energy conversion

This paper proposes a reconfigurable power module system for hybrid micro-grid to reduce the designing cost with standardized software and hardware components. The developed system is composed of three layers including application function layer, interconnection layer and physical layer with the capability to be interfaced with different types of energy resources for the hybrid micro-grid. By implementing the multi-layer power module system, the energy conversion designing procedures for different types of resources can be generalized and automated with less cost on the specified application scenarios. The control functions for different energy resources can be extracted from the application function layer. The desired number of standardized power modules can be integrated from the physical layer to form different power converter topologies. The coordination of the power converter, micro-controller, sampling, high level control is managed by the interconnection layer to construct the complete energy conversion system. The major advantageous results cover three aspects. Firstly, the proposed reconfigurable system generalizes the energy conversion of the hybrid micro-grid with different AC and DC resources. Secondly, the designing procedures of the hybrid micro-grid energy conversion system are simplified with less cost for various interfaced applications. Thirdly, the energy conversion performance and reliability of the micro-grid is improved with standardized power modules and self-restoration capability. The experimental test verified the proposed system.

Integrated Multipurpose Power Electronics Interface for Electric Vehicles

A novel integrated multipurpose power electronics interface (IMPEI) for the new generation of plug-in electric vehicles (PEVs) and plug-in hybrid electric vehicles (PHEVs) is proposed in this paper. The IMPEI is a reconfigurable power electronics interface (PEI) that integrates the onboard charger with the drive inverter allowing the same interface to be used for various modes of operation such as propulsion and regenerative braking as well as vehicle-to-grid (V2G) and grid-to-vehicle (G2V) operations with grid flexibility. For each mode of operation, the IMPEI is reconfigured into a previously existing power converter topology. The principles of operation and coordination of various modes of operation of the IMPEI are explained in this paper. Based on component count, operating modes, and control complexity, a comparison of the IMPEI and recently proposed integrated PEIs (IPEIs) is provided. Specifications of BMW i3 are used as the benchmark for comparing size, cost, and efficiency. This paper discusses and validates experimental results.

A Novel Modular, Reconfigurable Battery Energy Storage System: Design, Control, and Experimentation

This paper presents a novel modular, reconfigurable battery energy storage system. The proposed design is characterized by a tight integration of reconfigurable power switches and DC/DC converters. This characteristic enables isolation of faulty cells from the system and allows fine power control for individual cells toward optimal system-level performance. An optimal power management approach is developed to extensively exploit the merits of the proposed design. Based on receding-horizon convex optimization, this approach aims to minimize the total power losses in charging/discharging while allocating the power in line with each cell's condition to achieve state-of-charge (SoC) and temperature balancing. By appropriate design, the approach manages to regulate the power of a cell across its full SoC range and guarantees the feasibility of the optimization problem. We perform extensive simulations and further develop a lab-scale prototype to validate the proposed system design and power management approach.

Design theory of compact power divider with reconfigurable power division and negative group delay characteristics

This article presents the combined analysis of reconfigurable power division and negative group delay (NGD) in a power divider. A novel composite transmission line based reconfigurable power divider with high power division ratio, variable negative group delay, and lower characteristic impedance is presented in this work. The impedance transformation in composite transmission lines control both negative group delay and power division. This power divider possesses a wide range of power division ratios from 1 to 39, adequate isolation, impedance matching, and NGD of -3.4 ns to -4.7 ns in the reconfigurable transmission path. The negative group delay is achieved without using any additional group delay circuits. Theoretical equations corresponding to the low characteristic impedance of the transmission line sections and that of isolation elements are derived. The measurement results justify the attainment of high tuning of the power division ratio and negative group delay. Isolation and return loss are higher than − 15 dB at the centre frequency of 1.5 GHz. The significant contributions of this design can be listed as the wide reconfigurable power division along with negative group delay and reduced size.

A 28 GHz fully integrated GaN enhanced single‐sideband time‐modulated MMIC for phased array system

AbstractThis paper presents a 28 GHz GaN enhanced single‐sideband time‐modulated phased array (ESTMPA), based on a monolithic microwave integrated circuit (MMIC), including both a time‐modulated circuit and an RF front‐end module (FEM). The time‐modulated circuit mainly consists of a numerically controlled attenuator to balance the amplitude, compact phase shifters to generate balanced signals, a reconfigurable power divider, and a quadrature power divider. The FEM mainly consists of a low noise amplifier and a power amplifier, featuring codesign of input/output networks. Based on the in‐phase/quadrature (I/Q) composite modulation technique, a stepped modulation waveform, realized by the time‐modulated circuit, is used to enable a weighted array of phases. This helps generate a scanned beam at the first positive sideband and eliminate the undesired sidebands. The final MMIC‐based four‐element ESTMPA shows a relative suppression level of −16 dB at the positive fifth sideband and −13 dB at the zeroth sideband, and a much higher level at the other undesired sidebands. As a result, a wider signal bandwidth and a higher harmonic efficiency are achieved. In addition, the ESTMPA shows a beam sweeping angle from −30° to 30° in far‐field measurement.

Reconfigurable Power Circuits to Series or Parallel for Energy-Balanced Multicell Battery Pack

Multicell battery pack has the cells connected in series and parallel for fast charging and heavy load with low conduction loss. Thus, cell balancing control is required to maximize the utilization of the battery pack. The previous studies on cell balancing have used dedicated cell balancing circuits, including magnetic components and multiple capacitors. Instead of using additional passive components, this article proposes reconfigurable power circuits that only consist of power switches. With the merits of being reconfigurable into series or parallel in a multicell battery pack, the proposed circuits perform active cell balancing with a load capacitor and a load current for low cost and high system density. These features are essential for low-power applications with multiple cells, such as drones, wireless speakers, electronic point-of-sale, and mobile devices, which require compact system size. The operational principle, balancing features, and loss models of the proposed circuits are shown with a comprehensive analysis. A prototype board has been built to evaluate the performance of the proposed circuits with the experimental results. It is shown that the proposed circuits have a peak efficiency of 95.3% with 12 V, 1 A charging and 3.7 V, 0.4 A load.

A 2–10-GHz Reconfigurable GaN Power Amplifier With Average Power-Added Efficiency of 30% and Output Power of 2 W

In this brief, a 2–10 GHz reconfigurable power amplifier (PA) with power-added efficiency (PAE) of 30% and output power of 2W is proposed using commercial <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.25~\mathbf {\mu }\text{m}$ </tex-math></inline-formula> GaN technology. It consists of two-stage amplifier transistors with reconfigurable input, inter-stage and output matching networks. By utilizing the reconfigurable matching networks, the proposed PA circuit divides the frequency band of 2–10 GHz into three continuous sub-frequency bands, and achieves high power added efficiency and gain in each sub-frequency band. As a result, the proposed PA can simultaneously maintain high efficiency and high gain and cover multioctave bandwidth. Moreover, in order to further improve the efficiency, harmonic suppression is used in low-band with open circuit impedance at third harmonic. With these techniques, the proposed PA covers frequency band of 2–10 GHz, delivers an average PAE of 38% at 2–5 GHz, 31% at 5–7 GHz, and 31.5% at 7–10 GHz. Good agreement between simulation and measurement is obtained.

Fully epitaxial, monolithic ScAlN/AlGaN/GaN ferroelectric HEMT

In this Letter, we demonstrated fully epitaxial ScAlN/AlGaN/GaN based ferroelectric high electron mobility transistors (HEMTs). Clean and atomically sharp heterostructure interfaces were obtained by utilizing molecular beam epitaxy. The fabricated ferroelectric gate HEMTs showed counterclockwise hysteretic transfer curves with a wide threshold voltage tuning range of 3.8 V, a large ON/OFF ratio of 3 × 107, and reconfigurable output characteristics depending on the poling conditions. The high quality ferroelectric gate stack and effective ferroelectric polarization coupling lead to improved subthreshold performance, with subthreshold swing values approaching 110 and 30 mV/dec under forward and backward gate sweeps, respectively. The results provide fundamental insight into the ferroelectric polarization coupling and threshold tuning processes in ferroelectric nitride heterostructures and are promising for nitride-based nonvolatile, multi-functional, reconfigurable power, and radio frequency devices as well as memory devices and negative capacitance transistors for next-generation electronics.

Topology design of reconfigurable power splitter with pixelated Sb-based phase change materials

The waveguide-integrated reconfigurable power splitting is of great importance for on-chip all-optical connection. Based on the combination of silicon and Sb-based phase change materials (PCMs), a series of ultra-compact reconfigurable power splitters is topologically designed. The footprints of the functional regions are kept less than 1.0λ2. The power splitting ratio between the output channels can be reconfigured through the amorphous and crystalline switching of Sb-based PCMs. We demonstrate Sb2Se3-based and Sb2S3-based digital metamaterials for the reconfiguration between power splitting ratio of 5:5 and power splitting ratios of 5:5, 6:4, 7:3, 8:2 and 9:1. The three-dimensional FDTD simulations show that the targeted power splitting ratio can be achieved with acceptable precision. Moreover, the robustness of design is validated by introducing pixel errors.