Power Electronics Building Blocks Research Articles

Thermal Management for Ship Electrification - Approaches for Power Electronic Building Blocks and Power Corridors

Thermal Management for Ship Electrification - Approaches for Power Electronic Building Blocks and Power Corridors

The Versatile Buck-Boost Converter as Power Electronics Building Block: Changes, Techniques, and Applications

The versatile buck-boost (VBB) converter has been extensively studied because of its advantageous features such as step-up/step-down voltage conversion ratio, high efficiency, low-ripple continuous input–output currents easy to regulate, and the possibility of controlling any converter variable. These interesting features make it an excellent candidate to be a power electronics building block (PE-BB). This article summarizes the state-of-the-art PE-BBs and briefly describes the topological changes, control techniques implemented, and applications for which the VBB converter has been used so far. Finally, the experimental tests show that the proposed PE-BB can perform exceptionally well in dc–dc, ac–dc, dc–ac, and ac–ac applications.

The DC Transformer Power Electronic Building Block: Powering Next-Generation Converter Design

Power electronics has evolved from being only present in a few applications such as variable speed drives in the 1970s to becoming ubiquitous, present in almost every industrial application, and powering our daily life. In this ever-expanding market, power converters have become a mature technology covering a wide range of applications, providing solutions from a few watts (e.g., LED drivers) to gigawatts (e.g., high-voltage direct current systems). Competition has driven technology development in pursuit of cost reduction, increased efficiency, performance improvements, high power quality, higher power density, reliability, and an accelerated time to market. To meet these requirements, power converter design has been driven toward a more modular approach based on embedded systems, intelligent power modules, and power electronics building blocks (PEBBs) <xref ref-type="bibr" rid="ref1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[1]</xref> .

Paving the Path Toward the Use of Power Electronics Building Blocks [Editor’s Column

Over the last two decades, the application fields of power electronics have significantly grown. This underlying trend is primarily driven by the necessary and drastic reduction in CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> emissions to be achieved in the short term at a global scale. This imposes electrifying all types of transportation and entirely rethinking the grid to massively integrate renewable energy and storage systems. Other important sectors are also impacted, such as building and telecommunications, to name a few. Thus, by its intrinsic high flexibility in changing the nature of the current (ac to dc and vice versa) and voltage/current levels of use, power converters are naturally becoming essential to achieving this (r)evolution. This statement is also supported by a second important trend that consists of the ever pervasive use of digital technologies, whether at embedded or cloud levels. Indeed, power converters are easily digitally controllable, thus reinforcing their ability to adapt electrical power to any specific needs.

Commutation Behavior and Stray Inductance Analysis of a FC-3L-BDC Phase-Leg PEBB

The bidirectional dc-dc converter is a critical component for extending the use of renewable energy and improving the efficiency of high-power electronic systems. This paper presents the analysis of the stray inductance of a commutation loop and the commutation behavior of IGBT devices in a flying capacitor three-level bidirectional DC-DC converter (FC-3L-BDC) phase-leg power electronic building block (PEBB). An FC-3L-BDC phase-leg PEBB was designed as an example, which can be used to build 400 kW to MW-grade light rail train chargers, battery energy storage interface converters, or metro regenerative braking energy recovery converters with a single PEBB or several PEBBs interleaved parallel. In order to optimize the stray inductance of commutation paths and realize snubberless operation, a five-layer laminated bus bar was carefully designed, and the stray inductance of the bus bar was extracted by three-dimensional finite element analysis simulation. To obtain higher accuracy, the stray inductances of IGBT devices and capacitors were extracted from the test instead of their datasheets. Then, the accuracy of the commutation loop stray inductance analysis method was verified by practical experiments. The impact of the stray inductance of the commutation loop on the commutation behavior of IGBT devices was analyzed, and the switching characteristics of IGBT devices were measured under maximum DC-link voltage and entire current rating range at the temperatures of −40 °C, 25 °C, and 150 °C, respectively, finding that neither the excessive turn-off overvoltage of IGBTs nor the snappy reverse recovery of FWDs was observed.

Design of an Indirectly Coupled Filter Building Block for Modular Interleaved AC–DC Converters

This article presents the analysis and realization of a modular interconnected filter building block (FBB) operating under a single and multichannel (parallel three-phase converter blocks) configuration without loss of attenuation to any harmonic components. Emphasis is on the design of coupled inductor (CI) and boost inductor. In order to achieve a modular scheme with interleaved operation, indirect coupling between converters is realized using the secondary loop (SL)-based interconnection with inserted impedance. Here the “SL” serves as an additional pass for average grid side currents for <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</i> channels. A building block type configuration has been proposed using this topology, inspired by the power electronics building block (PEBB) nature. The purpose of the loop is to interconnect the parallel converters in series using an arrangement of CIs. In addition, a boost inductor has been introduced in the SL to realize a power factor correction rectifier operation. The CI serves as the circulating current filter while reflecting channel currents toward the SL. To meet conducted electromagnetic interference (EMI) limits, a two-stage <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LCLC</i> filter has been integrated with the FBB by introducing the point of common coupling (PCC) connection between two stages for filter size reduction. A design procedure is presented to meet power quality, circulating current, and EMI limits as per industry standards (EN-55011 and IEEE-519/1594). The proposed FBB has been characterized using 3L-NPC converters enabled with 1.2 kV Silicon Carbide based modules with comprehensive performance validation up to three channels in parallel with 15-kW power rating per channel.

High Power Density Medium-Voltage Converter Integration via Electric Field Management

SiC-based converters can achieve much higher voltage rating and power density than Si- based ones. Therefore, electric field (E-field) intensity inside SiC-based converters can become significantly high and initial partial discharges, especially along the exposed metal or insulator to air interfaces. To achieve discharge free by design, E-field intensity and insulation space in air need be carefully analyzed and well managed. Due to the complicated structure of power converters, sharp edges and corners cannot be fully avoided. Thus, E-field management should be considered for such critical regions, in order to make the E-field distribution more uniform and shrink the insulation size. In this article, by using the self-made medium-voltage power electronics building block (PEBB) as an example, critical regions for insulation design are identified. Then focusing on the region between the cooling system and the heatsink, the influence on E-field distribution with different guard rings&#x2019; shape, size, and location, is demonstrated. Following the simulation analysis and design comparison, six guard rings are fabricated and experimentally verified. Therefore, a methodology about E-field management for power converters is provided in this article, including critical region analysis, design comparison, guard ring fabrication, and experimental verification.

Evaluation of Modular Power Converter Integrated with 5G Network

This paper focuses on two key technical concepts, which may have a tremendous impact on future generations of power electronic converters: the Power Electronic Building Block (PEBB) concept, and the 5G/6G wireless data transfer. It is expected that these two trends may induce development of new cognitive of power electronic converters: Power Electronics 4.0. To investigate this concept, a Proof of Concept (PoC) of PEBB-based power converter integrated with a 5G network, was designed and tested. Study confirmed that power converter assembled from PEBB modules can compete with state-of-the-art devices. Moreover, test results indicates that several challenges related to PEBB and integration of power electronic equipment with 5G network has to be resolved, to enable growth of augmented power electronic converters, especially if wireless data transfer is meant for communication between PEBB modules.

Development of Supercapacitor Technology and Its Potential Impact on New Power Converter Techniques for Renewable Energy

To overcome short-term input energy fluctuations, and to offer complete 24-h energy solutions based on renewable resources such as solar and wind, energy storage devices are mandatory. A relatively new storage family is the supercapacitor (SC), which were developing rapidly over the last 15 years, and are yet to compete with rechargeable batteries. Today with three different commercially available SC families developing rapidly, with 1-70 000 F per single cell, at least one of them is reaching the specific energy of lead-acid batteries. All new families of SCs have charge/discharge life cycles of several orders larger than rechargeable battery chemistries, and their usage in energy storage systems is rapidly advancing. The SC-assisted converters are a new family of very low-speed converters, where a power electronic building block is combined with an SC bank to achieve high end-to-end efficiency, with the added advantage of dc-uninterruptible power supply (UPS) capability within the converter. This article provides an overview of the new SC-assisted loss management theory applied to SC-assisted converters, with practical examples of implementation useful in renewable energy systems such as SC-assisted low dropout regulator, SC-assisted LED, SC-assisted server rack power architecture, and SC-assisted wide-input inverter. In developing these new converters, useful in renewable energy systems, SCs are considered as a new device family with five to six-order larger capacitance for the same canister size, helping the achievement of the long time constant circuits.

WBG-Based PEBB Module for High Reliability Power Converters

The increasing presence of power electronic converters in the modern world - from electric vehicles, up to industrial applications - brings up concerns about their reliability, especially in the case of the Wide Band-Gap (WBG) devices. Moreover, ensuring high reliability becomes more challenging due to constantly increasing focus on the development of new types of power supplies in a shorter time. Thus, research over reliability improvement of modern power converters was initiated. In this paper, a concept of Design For Reliability (DfR) procedure, suitable for projects with a short lifespan, and a case study of Power Electronic Building Block (PEBB) designed according to the proposed procedure are presented. Furthermore, a Reliability Oriented Control (ROC) algorithm for WBG-based converters is discussed.

Design of a High-Efficiency, High Specific-Power Three-Level T-Type Power Electronics Building Block for Aircraft Electric-Propulsion Drives

The electric propulsion drives for the more-electric aircraft need lightweight and high-efficiency power converters. Moreover, a modular approach to the construction of the drive ensures reduced costs, reliability, and ease of maintenance. In this article, the design and fabrication procedure of a modular dc-ac three-level t-type single phase-leg power electronics building block (PEBB) rated for 100-kW, 1-kV dc-link is reported for the first time. A hybrid switch (HyS) consisting of a silicon insulatedgate bipolar junction transistor (IGBT) and silicon carbide metal-oxide-semiconductor field-effect transistor (MOSFET) was used as an active device to enable high switching frequencies at high power. The topology and semiconductor selection were based on a model-based design tool for achieving high conversion efficiency and lightweight. Due to the unavailability of commercial three-level t-type power modules, a printed circuit board (PCB) and off-the-shelf discrete semiconductor-based highpower switch was designed for the neutral-point clamping. Also, a nontrivial aluminum-based multilayer laminated bus bar was designed to facilitate the low-inductance interconnection of the selected active devices and the capacitor bank. The measured inductance indicated symmetry of both current commutation loops in the bus bar and value in the range of 28-29 nH. The specific power and volumetric power density of the block were estimated to be 27.7 kW/kg and 308.61 W/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , respectively. The continuous operation of the block was demonstrated at 48 kVA. The efficiency of the block was measured to be 98.2%.

A Rotational Control in Medium-Voltage Modular Solid-State Transformer-Based Converter System

This paper presents a novel control strategy to significantly reduce the high-frequency transformer loss in a modular solid-state transformer (SST) based converter system. The modular SST design is based on an ac–dc power-electronic building block comprised of an H-bridge at the ac input and a bidirectional soft-switching isolated dc–dc converter with a medium-voltage insulated high-frequency transformer. The ac terminals of input H-bridges are connected in series and directly coupled to the medium-voltage ac line, while the output dc terminals are all connected in parallel at a low voltage. The key innovation described in this paper, without sacrificing the output performance, is the control scheme that reduces core and winding losses associated with the dc–dc resonant stage by turning off the selected dc–dc converters in synchronism with the line voltage. The prototype for the test described in this paper is based on a modular SST where each module is rated at 50 kVA, with a 200 kHz transformer using 1.7 kV silicon carbide discrete mosfet s, but the described control concepts are more broadly applicable to similar topologies.

Design and Evaluation of Laminated Busbar for Three-Level T-Type NPC Power Electronics Building Block With Enhanced Dynamic Current Sharing

This article focuses on providing the laminated busbar design guidance for a three-level T-type neutral-point-clamped (3L-TNPC) inverter to achieve low stray inductance and balanced inductance distribution between paralleled power switches. As a result, equalized dynamic current sharing can be accomplished. To discover the design strategy, this article first derives the mutual-inductance-decoupled equivalent circuit for 3L-TNPC. Then, the effects of each inductance item on switching performance can be unveiled, and the parametric targets are then summarized. Accordingly, the busbar design considerations are discussed. A step-by-step busbar design procedure to achieve the aforementioned design targets is provided in the next. The design procedure starts from 2-D optimization to achieve the optimal component and terminal allocation, and then, it increases the optimization degree to 3-D. Using this design procedure, we proposed a novel double-side-end busbar structure to achieve the busbar stray inductance of 12.7 nH and the inductance differences between the paralleled switches to be less than 2 nH. Extensive experiments are carried out in the end to evaluate the design procedure and demonstrate the performance of the busbar.

Power Electronics Modeling and Design: Using Parametric and Model-Form Uncertainty Quantification to Assess Predictive Accuracy of Power Converter Models

This article presents an enhanced modeling framework for the design of power electronics converters and systems. This methodology provides the means to assess and quantify the predictive accuracy of power converter models, a capability that is attained by the proper identification, characterization, and quantification of the different, and often numerous, sources of uncertainty in the modeling and simulation process. For illustrative purposes, an in-depth example is presented using a power electronics building block (PEBB) as the modeling test bed, demonstrating how, through this formal modeling procedure-and taking into consideration the uncertainties in the system-the model in question can predict the variable of interest within a known range with a given level of confidence, without requiring heuristic safety factors. This predicted range can be used as the required design margin when the selected output is a design variable, evincing the inherent potential of having a less conservative and more reliable power converter using the design methodology with uncertainty quantification.

Analysis and Design of a 1200 V All-SiC Planar Interconnection Power Module for Next Generation More Electrical Aircraft Power Electronic Building Blocks

Compact, light weight and efficient Power Electronic Building Blocks are seen as fundamental components of future More Electric Power Systems, e.g. More Electrical Aircraft. Core elements supporting the trend are power modules employing solely SiC MOSFETs. In order to take advantage of the high switching speed enabled by SiC, novel modules concepts must be investigated. For example, low inductance planar interconnection technologies, integrated buffer capacitors and damping networks are possible solutions to mitigate switching overvoltages and oscillations at the switching node occurring for conventional modules. In this paper, the analysis and the design of a novel ultra-low inductance 1200 V SiC power module featuring an integrated buffer-damping network are discussed. The power module is first described and characterized with impedance measurements. Afterwards, a general optimization procedure for the sizing and the selection of the integrated components is presented and measurements are performed to verify the analysis and to highlight the improvements of the proposed solution.

Medium-Voltage Impedance Measurement Unit for Assessing the System Stability of Electric Ships

This paper describes the design and implementation of the first medium-voltage impedance measurement unit (IMU) capable of characterizing in situ source and load impedances of dc and ac networks (4160 V ac, 6000 V dc, 300 A, 2.2 MVA) in the frequency range of 0.1 Hz–1 kHz. The IMU comprises three power electronics building blocks (PEBBs), each built using 10-kV SiC MOSFET H-bridges. The modularity of the PEBBs allows for both series and shunt perturbation injection modes to be realized, as both injection modes are needed to accurately predict the stability of the electrical system. The effectiveness of the proposed impedance identification approach is experimentally verified on medium voltage power grid.

Size and Weight Computation of MVDC Power Equipment in Architectures Developed Using the Smart Ship Systems Design Environment

The smart ship systems design (S3D) environment under development is intended to enable users to estimate the size and weight requirements for various devices and subsystems of a naval vessel. This paper continues work done related to the modular multilevel converter (MMC) scaling approach and applies it to other devices of the medium voltage dc (MVdc) portion of the power network. The analysis shown uses a 10 kV baseline ship design within S3D and uses the developed scaling values to calculate the total weight and volume of particular equipment. Comparisons between power densities of the overall MMC system at different MVdc bus voltages and using power electronic building blocks of different ratings are also shown. This provides vital insight that enables S3D users to assess and evaluate different power architectures using metrics such as functionality, mass, and volume among other factors.

Series-Input Parallel-Output Modular-Phase DC–DC Converter With Soft-Switching and High-Frequency Isolation

Multiphase soft-switching high-frequency isolated dc–dc converter is proposed for power conversion in modular stacked HVDC power transmission and distribution system. Input-series output-parallel connection of current-fed full-bridge dc–dc converter modules is proposed to increase voltage blocking capability at the input and decrease current ripple at the output. Basic power electronic building block is zero-current switching (ZCS) full-bridge phase-shift pulsewidth-modulated (PWM) dc–dc converter. Phase shift between switches in each leg of the converter is adjusted to control power flow, while phase shift between gate signals of individual phases is selected according to the number of phases in order to minimize ripple of the output voltage. Converter analysis is carried out to develop a simple equivalent boost converter model of the three-phase soft-switching converter suitable for system-level analysis and simulation. Strategies are developed to ensure fast detection of faults and continued operation of the converter in the case of fault in one phase module. To verify the proposed system design and analysis, experimental results on scaled-down laboratory prototype are presented for a three-phase ZCS dc–dc converter.

Advances in Power Conversion and Drives for Shipboard Systems

This paper presents some of the key advances in power electronics pertaining to shipboard electric power system applications. The focus is on the emerging wide bandgap semiconductor devices, i.e., silicon carbide (SiC) and gallium nitride (GaN) devices, and their potential impact on future shipboard power conversion and drives. Their benefits on power converter efficiency and power density are explained through a case study of a medium-voltage (MV) class motor drive system. SiC and GaN also enable new applications, including solid-state transformers, while posing new design and application challenges such as gate drive, protection, and interaction with loads. In addition to device related topics, this paper also overviews other important advances in power electronics, including topology, control, passive components, thermal management, filters, and packaging. The significance of power electronics building blocks (PEBBs) concept for shipboard power system development is discussed. Recognizing the growing complexity of shipboard power systems, some system-level technologies related to future MV direct current (dc) system architecture are highlighted.

Design and Research on High-Reliability HPEBB Used in Cascaded DSTATCOM

The H-bridge inverter is the fundamental power cell of the cascaded distribution static synchronous compensator (DSTATCOM). Thus, cell reliability is important to the compensation performance and stability of the overall system. The concept of the power electronics building block (PEBB) is an ideal solution for the power cell design. In this paper, an H-bridge inverter-based &#8220;plug and play&#8221; HPEBB is introduced into the main circuit and the controller to improve the compensation performance and reliability of the device. The section that discusses the main circuit primarily emphasizes the design of electrical parameters, physical structure, and thermal dissipation. The section that presents the controller part focuses on the principle of complex programmable logic device -based universal controller This section also analyzes typical reliability and anti-interference issues. The function and reliability of HPEBB are verified by experiments that are conducted on an HPEBB test-bed and on a 10 kV/&#xb1; 10 Mvar DSTATCOM industrial prototype.