HOW2POWER TODAY

ISSUE: September 2024

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IN THIS ISSUE:

» A Practical, Easy-To-Implement Energy Harvester For BLE Modules And Other Applications

» Designing An Open-Source Power Inverter (Part 19): Controller Design For The Battery Converter

» Focus On Magnetics:
Can Foil Folding Improve Winding Performance In Transformers?

» Special Guest Commentary:
Transitioning Voltage Regulator Design From Unidirectional To Bidirectional

» Power Products

» Industry Events

» New on How2Power.com

» Other Top Power News

Bidirectional power flow has been a topic of discussion in the industry for some years now both because of the emergence of applications requiring bidirectional energy flow, and also the ongoing development of bidirectional power switches that will enable further advances in converter design. In terms of bidirectional energy flow, there are some examples seeing adoption in the marketplace. In electric vehicles, inverters may have bidirectionality to enable regenerative braking and on-board chargers (as well as external fast chargers) may be bidirectional to allow for V2G (vehicle to grid) and similar new applications. On a smaller power scale, there is the bidirectional charging offered in USB-C power delivery. Meanwhile, in the laboratory, we can find examples of benchtop power supplies with bidirectional operation for testing a variety of power-related applications including photovoltaic systems, energy storage systems and batteries, EV inverters, dc-dc converters, and other products. The trends seem to be pointing to a future in which power flow is increasingly bidirectional. Yet, the vast majority of power converter designs today remain the conventional, unidirectional dc-dc converters (isolated and nonisolated) powering electronic loads such as CPUs, FPGAs, etc. For those tasked with designing bidirectional dc-dc converters, the options for controller or converter ICs on which to build such designs are quite limited and the task may be disorienting. In his commentary, Reno Rossetti aims to ease this transition by offering some insights into bidirectional converter operation. As Rossetti explains there are inherent elements of bidirectional power flow that already exist in the familiar power converters which can offer a basis for grasping bidirectional topologies such as the phase-shift dual active bridge. As electrification of transportation proceeds, and we work toward building a flexible power grid, more power designers may find themselves needing to make this “mindset adjustment” described by Rossetti to adapt to a world in which energy sources and power systems are expected to be more versatile.

HOW2POWER EXCLUSIVE DESIGN ARTICLES

A Practical, Easy-To-Implement Energy Harvester For BLE Modules And Other Applications

by Ron Demcko, Daniel West, Ryan Messina and Ashley Stanziola, KYOCERA AVX, Fountain Inn, S.C.

This article builds on prior investigations of supercapacitors and tantalum capacitors as well as an energy harvesting controller IC used to power ULP devices. For this work, we employed the same IC (the e-peas AEM10330) to extract energy from a small solar cell, store it in a supercap, and power a Bluetooth Low Energy (BLE) module. The BLE module, in turn, was configured to measure the voltage of the supercap and the voltage supplied to the module, and then transmit those values to a PC for data logging. This real-world example of an energy-harvesting system demonstrates the ease with which such a system can be created. Read the article…

The prototype for testing the viability
of the proposed energy harvester
and BLE measure/transmit system.

Although this circuit is structurally
that of a Weinberg circuit, it contains
a refinement that changes the control
scheme so that it operates as a dual-mode
circuit: a buck (CP) for the low-output
condition (V_s’ < V_g) and a boost (CA)
for higher output power requirements.

Designing An Open-Source Power Inverter (Part 19): Controller Design For The Battery Converter

by Dennis Feucht, Innovatia Laboratories, Cayo, Belize

The last four parts in this series on the Volksinverter have provided extensive discussion on the design of the transformer for the battery converter. Keeping the focus on this stage, in this article we now explore the design of the control circuit of the boost push-pull (BPP) power-transfer circuit. We will begin this explanation of control circuit design by observing how low output-voltage and output-current conditions on the battery converter’s output port complicate converter control. Then, we’ll see how to address these requirements by applying a combination of operating modes, and derive the control logic needed to implement these two modes. Based on those logic requirements, a particular control scheme will be recommended. Finally, the various exceptions to the normal controller operating modes will be described. Read the article…

FOCUS ON MAGNETICS       
Sponsored by Payton Planar Magnetics
A monthly column presenting information on power magnetics design, products, or related technology

Can Foil Folding Improve Winding Performance In Transformers?

by Dennis Feucht, Innovatia Laboratories, Cayo, Belize

Foil as a conductor shape can have advantages over wire. This article explores methods for winding with it. The concept is somewhat reminiscent of origami or Japanese paper folding, though the constraints on winding performance are an additional consideration. Here I’ll explore various ideas about how to wind with foil. Although optimal-thickness foil reduces eddy-current constant-frequency resistance ratio F_r to valley values between the low-ξ and medium-ξ regions on Dowell graphs, it lacks the F_r minimization achieved by twisting wire into bundles. If the eddy-current benefits of twisted conductors could be combined with the advantages of foil, winding design might be advanced. This article is a presentation of ideas or “brainstorm” intended to encourage discovery of new folding methods that enhance the use of foil in winding design. Read the article…

SPECIAL GUEST COMMENTARY

Transitioning Voltage Regulator Design From Unidirectional To Bidirectional

by Nazzareno (Reno) Rossetti, Alphacore, Tempe, Ariz.

Energy management systems (EMSs) are an emerging set of applications aimed at optimizing the energy flow and storage between electric vehicles, photovoltaic systems, home storage batteries and the electric grid. Such flexible energy management requires that fundamental blocks like voltage regulators and chargers, connected to the EMSs, operate bidirectionally with respect to the energy flow. However, the vast majority of today’s blocks power traditional unidirectional loads. A designer that has thus far designed only unidirectional dc-dc converters will find himself/herself in a quite unchartered territory when asked to design an eminently bidirectional phase-shift dual active bridge (DAB) converter. Hence, designers looking to do their first bidirectional converter designs may benefit from some background on how these relate to conventional, unidirectional power converters. As we’ll see, there are already elements of bidirectional energy flow in the familiar unidirectional converters. Read the full story …

POWER PRODUCTS

INDUSTRY EVENTS

IEEE Energy Conversion Congress & Expo (ECCE 2024) Is Coming To Phoenix

by David G. Morrison, Editor, How2Power.com

Entering its 16th year, the IEEE Energy Conversion Congress & Expo (ECCE 2024) is coming to Phoenix, Ariz., October 20-24, with an extensive program packed with nearly 1200 papers, presented in oral and poster sessions, plus luminaries special sessions honoring John Kassakian and Hirofumi (Hiro) Akagi, and 16 special sessions including one in memory of Ned Mohan. ECCE 2024 also boasts a lineup of 27 tutorials. Following its record-breaking attendance last year, ECCE 2024 is looking forward to continued growth with approximately 2400 attendees expected in Phoenix, and a bustling expo with around 60 exhibitors and 15 corporate sponsors. Read the full story …

Power Electronics Community To Gather On Long Island

The Long Island Power Electronics Symposium & Exhibits, the area's premier annual event for the power electronics community, will take place on Thurs., November 7, 2024 at the Hauppauge Radisson. Attendees may arrive and leave anytime from noon to 8 PM. All professionals (engineers, managers, etc.) involved in the use, design, qualification, test, procurement or manufacture of power supplies, power converters, power management, servos or energy storage are invited. All sectors of power electronics are represented including military, industrial, medical, space, consumer and automotive. This event is free for attendees, but attendees are asked to register in advance. Registered attendees will receive admission to the exhibit floor, technical lectures, and complimentary lunch and dinner. The first 200 registered attendees will also receive a complimentary swag bag with gifts from exhibitors. More details can be found here.

CS MANTECH 2025 Issues Call For Papers

The International Conference on Compound Semiconductor Manufacturing Technology (CS MANTECH), which will be held May 19-22, 2025 in New Orleans, has issued its first call for papers. Among the many papers topics addressed at this conference are power devices, advanced packaging, and power conversion. For more information, see the call for papers.

NEW ON HOW2POWER.COM

NSREC Notes: Rad-Tolerant Power Devices, Reference Designs, And GaN-based Products Continue To Increase As Vendors Expand Space Portfolios

Read the article …

Calendar of Events — Over 350 Listings For 2024

HOW2POWER’s Events Calendar lists selected conferences, tradeshows, workshops and webinars related directly or indirectly to power electronics. Our calendar currently lists over 350 of the electronics industry’s top events for 2024 and over 50 events for 2025.

Visit this section …

OTHER TOP POWER NEWS

To address switching energy loss in wide-bandgap and silicon power devices, JEDEC has published “JEP200: Test Methods for Switching Energy Loss Associated with Output Capacitance Hysteresis in Semiconductor Power Devices,” which is available for free download.

Infineon Technologies has developed what’s described as the world’s first 300-mm power GaN wafer technology.