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Ideal Power’s control methodology, Power Packet Switching Architecture (PPSA), unites high-performance power switches with advanced software controls, dramatically reducing the weight of power conversion systems and eliminating the need for the isolation transformer and other passive components required for conventional voltage-source power conversion systems (PCS). Multiport PCS are also part of the Ideal Power product portfolio. The direct integration of photovoltaic (PV) and energy storage is achieved by adding power switches while minimizing additional passive components.

Today’s Energy Solutions sat down with Ryan O’Keefe, senior vice president of business development at Ideal Power, to discuss his company’s technology and how the energy industry can benefit from its grid-edge and distributed-generation capabilities.

Today’s Energy Solutions: How does Ideal Power’s PPSA differ from traditional power conversion systems?

Ryan O’Keefe: Traditional systems employ big, bulky, brute-force-method analog power converters. If you think about other power conversion methods, DC-to-AC conversion is done by turning the DC signal, which is just a straight line of voltage, and capping that up into a square wave, and “smooshing” the square wave with filters into something that looks like a sine wave. So, it’s a continuous process. It’s somewhat inefficient because it requires a lot of capacitors, filters, and there are a lot of stages in the process. In addition, you need to put it through an isolation transformer, separated from the grid.

The way Ideal Power does it is through modern computing technologies that weren’t powerful enough to perform this function as recently as 10 years ago. Basic mathematics shows that you can approximate a curve by chopping up little bits of the curve and adding up all of the little squares of the chopped curve. Basically what we’re doing is making a curve with thousands of these rectangles of different sizes and fitting them under the curve. We are making a completely digital power converter that is really just a fast, advanced computer that switches at a very high frequency to fit the digital signal into an analog curve.

Ideal Power was founded by Bill Alexander who is the company’s CTO and has a mechanical engineering degree from the University of Texas. As a mechanical engineer, Bill had this idea that he could take a different approach than the traditional model for power conversion. So, we break up this DC voltage/signal from a battery or from a PV array into little chunks and we move them very fast (14,000x/sec.) into what becomes a perfect sine wave. And we do the same thing in reverse. We take that sine wave and we break it up and rectify it to make a nice digital signal going back. We’re a fast computer power converter, and we have well-patented IP around how to do this.

TES: What are some applications for Ideal Power’s technology?

O’Keefe: Today, the highest value use of our technology is through the energy-storage connected world. Because we’re bidirectional, we can push and pull power. We like working with batteries because batteries need digital-to-analog conversion in both directions to work with the grid. We also work with PV, diesel generators, electric vehicle-to-grid applications, and other generation sources. We haven’t done any wind-specific projects outside of a prototype, but that is something we are looking into.

TES: What are the user benefits of the PPSA?

O’Keefe: Because of the way we work with this fast switching methodology, the inputs and outputs are never connected at the same time. So even though the switching is happening very fast, the input and output switches never meet. We naturally get isolation that’s required through our switching algorithms, so the wires during the inputs and outputs are never touching. In a traditional system, wires are touching from beginning to end in a continuous process. Ideal Power uses a discrete process. In a continuous process, you need to isolate from the grid with an isolation transformer. We don’t need that, and that adds to substantial energy efficiency and reduction of cost and space. We think our transformerless design can save the customer approximately 10 cents per watt in shipping, installation, and efficiency by getting more use of their batteries by minimizing loss though the system.

In terms of shipping costs, our 30kW products are shipped and delivered anywhere in the U.S. within three days. Competitor products take much more time to transport because they weigh anywhere from 650 lb to 800 lb whereas ours weigh around 97 lb. So, that logistical cost is substantial at the user site, and with PPSA, users get more use of the energy they’re generating. Also, our products mount on a wall without taking up any floor space and are all scalable.

TES: What do you see in the future with Ideal Power?

O’Keefe: We are continually developing products around our technology. We are currently developing a variable frequency drive and a motor control drive based on our PPSA technology.

TES: Ideal Power’s 30B3 family is certified for North American grid applications. is the company looking at other certifications?

O’Keefe: We are looking at more. We are doing our first international demonstration projects overseas this year with both 30kW and our 125kW product family. We expect that we’ll pursue more in the international market with international certifications for these products soon.

Both are products that can operate at any grid voltage and in any frequency in the world. In the power world, there’s basically two frequencies – 60 cycle (60Hz) and 50 cycle (50Hz). The functionality is built in; it’s just a matter of when to scale and going after commercial deployment. Many of our distributors have oversees contacts already.

Ideal Power

www.idealpower.com

About the author: Arielle Campanalie is the associate editor TES and can be reached at 216.393.0240 or acampanalie@gie.net.