Storage Highlights countdown #2: E3/DC Multi-string three-phase battery inverter technology


pv magazine has evaluated and assessed a range of energy storage innovations and applications for the upcoming Energy Storage Europe in Düsseldorf (March 13-15).

Our highlights ranking awards the top 10, based on the scores of an expert, independent jury, which assessed a total of 24 candidates. The full ranking is published in the pv magazine energy+storage special issue, created in cooperation with Messe Düsseldorf.

After publishing, last week, a preview on the fifth, fourth and third technologies in the ranking –  Electrochaea’s scalable methanathan plant, Fraunhofer ISE’s Cell-Booster and SMA large-scale turnkey solution Medium Voltage Power Station for the global market – over the next few days, we will publish in descending order, the Top 2 products and innovations that were awarded for their excellence. This time we approach…

#2 E3/DC Multi-string three-phase battery inverter technology

Highly rated by several of the jurors, E3/DC made it into second place overall. If you look at the individual highlight categories, the manufacturer of small and medium-sized storage systems scored particularly high for innovation.

The company, already well known for its residential storage system, has submitted a new technology for a DC-DC converter for battery storage systems, with which users can better control the state of charge. This is especially important for emergency power systems.

In addition, the power electronics have a high discharge capacity with efficiency of up to 98%, even if you connect 48 volt battery modules. This allows a C-rate of 1 and a maximum output current of 120 amps. According to E3/DC, the trick is a new topology with galvanic isolation and an ultra-high frequency allowing for small components. The inverter will be used in the 12 kW battery systems of the company.

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The challenge for the innovative state-of-charge-control is that no lithium battery system can have an accurate state of charge measurement without being discharged and charged from time to time, states the company. If you measure the state of charge in this way, the battery may be empty in an emergency. The solution is to operate two battery modules asymmetrically. As one is discharged, the other holds a defined state of energy.

The comments in the jury on the product are varied. One juror sees technical innovation, but is not sure about the business relevance. Another is not sure about the USP, but places emphasis on the strong contribution to the energy transition.

E3/DC booth at Energy Storage Europe can be found at Hall 8b / B22.

Find out #1… in the ranking on Wednesday, March 7.

The Energy Storage Highlights Jury comprises:

  • Logan Goldie Scot, who heads up the Energy Storage insight team at Bloomberg New Energy Finance.
  • Tobias Federico, Founder and Managing Director of consulting institute Energy Brainpool.
  • Dirk Uwe Sauer, Professor of Electrochemical Energy Conversion and Storage Systems Engineering at RWTH Aachen University.
  • Julian Jansen, a Senior Market Analyst at IHS Markit Technology.
  • Stephan Schnez, Senior Scientist in Corporate Research at ABB in Switzerland.

Read more about the Energy Storage Highlights ranking, criteria and the selection process in the pv magazine energy+storage special.

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