editor's blog
Subscribe Now

Towards Smaller Solar Inverters

Inverters are getting smaller.

We’re talking here about the inverters used in solar cells to convert the DC that they generate into AC for the grid. But there seem to be a couple of different motivations for this reduction in inverter size; I was made aware of them by a two different product releases.

First came an SoC from Semitech. Semitech has primarily been focused on power-line communications (PLC) on the so-called Smart Grid. Their focus hasn’t so much been on residential settings, where broadband connections dominate, but rather longer-distance machine-to-machine narrowband connections. We’re talking hundreds of (electric) meters communicating over a few kilometers.

That said, they noticed an opportunity. Traditionally, a single inverter will serve multiple panels; this helps keep cost down (always an issue as solar struggles to compete with other forms of energy). But Semitech notes that there are some weaknesses with this arrangement. In particular, the one inverter becomes a single point of failure that can take all of its panels out of action. Efficiency also gets tuned to the needs of the worst (e.g., most shaded) panel – meaning that energy is wasted from the other panels.

The ideal would be a micro-inverter for each panel – something that’s generally been a cost challenge. So Semitech is trying to reduce that added cost by integrating the inverter electronics (not the transformers) into the PLC chip. So any inverter that was intended to communicate could get the inverter control circuitry almost for free (it’s a small add-on to the PLC circuitry, which dominates the chip).

Semitech_image_ret_copy.png

(Click to enlarge)

Image courtesy Semitech.

By the way, apparently the same chip can be used for LED control if loaded with different software.

Meanwhile, ST Microelectronics announced a rather simpler product: an SiC diode. It replaces larger devices that have been needed in order to provide sufficient overcurrent margin. The new SiC diode can handle higher current spikes, contributing to a smaller inverter.

In this case, the small-inverter drive comes from a project driven by Google and IEEE called The Little Box Challenge. Here the idea is that smaller inverters will reduce the size of the cooler-sized box that’s currently needed for a residential solar installation. That makes it less of an eyesore, reduces the footprint, and – critically – reduces cost.

If you’re not part of the Challenge yet, it’s too late; registration is closed. The final prize will be announced next January.

That said, ST also seems heavily focused on the automotive market, saying that the new diode meets the requirements for such applications as on-board battery chargers for plug-in hybrids. It has a reverse breakdown of 650 V, and they boast zero recovery time.

ST_screenshot.png
 

Image courtesy ST Microelectronics

You can find out more about these two products in the releases (Semitech and ST); you can find out more about the Little Box Challenge here.

Leave a Reply

featured blogs
Feb 28, 2021
Using Cadence ® Specman ® Elite macros lets you extend the e language '”€ i.e. invent your own syntax. Today, every verification environment contains multiple macros. Some are simple '€œsyntax... [[ Click on the title to access the full blog on the Cadence Comm...
Feb 27, 2021
New Edge Rate High Speed Connector Set Is Micro, Rugged Years ago, while hiking the Colorado River Trail in Rocky Mountain National Park with my two sons, the older one found a really nice Swiss Army Knife. By “really nice” I mean it was one of those big knives wi...
Feb 26, 2021
OMG! Three 32-bit processor cores each running at 300 MHz, each with its own floating-point unit (FPU), and each with more memory than you than throw a stick at!...

featured video

Silicon-Proven Automotive-Grade DesignWare IP

Sponsored by Synopsys

Get the latest on Synopsys' automotive IP portfolio supporting ISO 26262 functional safety, reliability, and quality management standards, with an available architecture for SoC development and safety management.

Click here for more information

featured paper

How to Fast-Charge Your Supercapacitor

Sponsored by Maxim Integrated

Supercapacitors (or ultracapacitors) are suited for short charge and discharge cycles. They require high currents for fast charge as well as a high voltage with a high number in series as shown in two usage cases: an automatic pallet shuttle and a fail-safe backup system. In these and many other cases, the fast charge is provided by a flexible, high-efficiency, high-voltage, and high-current charger based on a synchronous, step-down, supercapacitor charger controller.

Click here to download the whitepaper

Featured Chalk Talk

Protecting Circuitry with eFuse IC

Sponsored by Mouser Electronics and Toshiba

Conventional fuses are rapidly becoming dinosaurs in our electronic systems. Finally, there is circuit protection technology that doesn’t rely on disposable parts and molten metal. In this episode of Chalk Talk, Amelia Dalton chats with Jake Canon of Toshiba about eFuse - a smart solution that will get rid of those old-school fuses once and for all.

Click here for more information about Toshiba efuses