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very little relationship to how the Ballistic Breaker works.

Monday, November 12, 2012


This announcement appeared on numerous websites on November 8, 2012:
Switzerland-based ABB today announced that it has developed the world’s first circuit breaker for high voltage direct current (HVDC), solving what it says has been “a 100-year-old electrical engineering puzzle and paving the way for a more efficient and reliable electricity supply system.” The breakthrough holds promise not just for renewables development but also for all types of generation that nations and regions wish to transmit over long distances, including under large bodies of water. Read More »

There were many followup analyses after ABB's announcement, but the above link to Power Magazine was my favorite, and they got quotes from the right people!

Just to show what a big deal this is, consider this link to a story about ABB unveiling a productized version of their HVDC breaker at the 2014 Hannover Messe 2014 meeting in Paris, showing Angela Merkel and ABB Chief Executive Officer Ulrich Spiesshofer.

“Let’s get started with building the new power grid!” Merkel told ABB CEO Ulrich Spiesshofer, who was briefing her on how ABB’s high-speed HVDC breaker, shown publicly for the first time at the fair, will enable power grids that outpace existing networks’ efficiency while preventing grid collapse.

This paper from the 2011 CIGRE conference in Bulogna describes their breaker concept pretty well. Here is a diagram of the breaker:

HERE is a link to US patent 8,891,209 a refinement patent with a very readable synopsis of how the original hybrid breaker worked. The high importance that ABB places on this technology is evident from the fact that they also have applied for several other versions of HVDC hybrid circuit breakers.

Their new device is described in US patent 8,717,716 (among others), but the picture (above) from the Bologna CIGRE paper is much better for understanding how it works than the patent document. Although the auxiliary switch used for HVDC is an IGBT, at lower MVDC voltage, the auxuiliary switch can be an IGCTs (integratedgate commutated thyristors). or a MOSFET. IGCTs were first introduced in shipboard DC circuit breakers (for 980 volt service) by ABB Marine in 2011. (This paper by Jean-Marc Meyer and Alfred Rufer describes how the hybrid breaker principle can be applied at MVDC, using IGCTs.) The fast electromechanical switch could be of several designs (ABB has several patents in this area; my personal favorite is US patent 6,501,635). 

The 2 to 5 ms delay that ABB cites in operation of their breaker (different numbers quoted in different places; which is quite fast compared to most prior art breakers) is not the time until current stops flowing, but the time at which di/dt changes sign and the current starts being reduced.  This delay is due to the fast mechanical switch, which must open far enough to prevent restriking an arc before the main IGBT array can be opened. The hybrid nature of the commutation differentiates ABB's approach from Lian's US patent 3,534,226, which is also one of the closest prior art patents to my Ballistic Breaker patent application

The ABB device works in this way: there is a parallel circuit between three pathways: in the middle is a series connected IGBT array that is capable of shutting off the HVDC circuit and withstanding an overvoltage higher than the normal line voltage. In this series-connected IGBT array, each IGBT component is shunted through a metal oxide varistor (MOV) that allows current to flow when voltage goes above a selected level. All the component IGBTs of the IGBT array could be switched off simultaneously; in this case there would be a rather large voltage spike as the voltage rises at least 50% over normal voltage to activate the string of series-connected MOVs. Note though that the individual IGBTs can also be switched off sequentially to control the over voltage during breaking of the circuit. (The overvoltage is due to insertion of resistance into the circuit; absorption of inductive energy by the MOVs is not instantaneous, so the current must continue to flow as the energy is dissipated. Voltage rises each time resistance increases, followed by decay in the case of ordinary resistors; for an inserted MOV, voltage is held nearly constant as the stored magnetic energy in the circuit is dissipated.) 

The big headache with any circuit breaker but especially an HVDC circuit breaker, is that the line inductance can vary a lot depending on where the short is located, and the current flowing at the time of the fault can also vary. ABB's method of rapid adaptive switching while opening the circuit was clearly anticipated in Lian's patent from 1970; the switching times for the various IGBTs can be varied to control the switching transients and the times allowed for decay between switching events to squelch the inductive energy in the flowing current in an optimized manner. Alternatively, one can just make a worst case assumption and switch on that basis (this is what happens in a Ballistic Breaker).  Or (most crudely) all the IGBTs in the array can be switched simultaneously, in which case the MOVs control the switching surge (but not very well). 

By controlling the switching of the IGBTs the voltage transient due to the voltage rising high enough to push current through the MOVs is split into many small parts, which can keep the overvoltage quite low if the timing of closing the IGBTs is properly controlled. Collectively, the MOVs must have enough capacity to absorb all the magnetic energy stored in the line, which can be hundreds of MJ, implying that the MOV array weighs a metric ton or so for a long HVDC line. An individual MOV begins to conduct around 1.5X the normal line current, so if all the IGBTs were switched simultaneously the voltage during shutoff could go to ~1.5-2X the normal line voltage. However, by controlling the switching time of the individual IGBTs the voltage switching transient could be much lower. This part of the breaker (the IGBT array) in isolation is the "power electronic breaker" to which Ram Adapa refers in the Power Magazine article cited above. 

The much lower resistance of the single IGBT or IGCT used for commutation means the on-state losses are (according to ABB's CIGRE paper) in the low tens of kW for a 2kA, 320kV HVDC line; if we take that to mean 40kW on-state loss in the commutating IGCT/IGBT, that implies only ~0.005% of transmitted power. This is much better than the on-state loss for an IGBT-based switch in which all the current flows all the time through the entire IGBT array, for which the on-state loss would be ~0.25% of power at full rated power. The ABB breaker is much better than that, and does indeed usher in an era where large interconnected high power HVDC grids (supergrids) can be protected by circuit breakers. I believe ABB's breaker will be more expensive than my Ballistic Breaker or a hybrid Ballistic Breaker, which follows the same idea as ABB's design of using a fast switch to do the first commutation to the device which ultimately opens the circuit, but where the circuit is opened via the electromechanical commutating circuit breaker (which I have been calling a Ballistic Breaker). I welcome ABB's innovation as the first viable HVDC circuit breaker, and I look forward to competing with them.

ABB's approach cuts the on state power losses, because in the on state, most of the power only goes through the low loss low voltage IGCT or IGBT, but makes an even more expensive circuit breaker than a simple IGBT-based switch with MOVs (which Ram Adapa mentioned in the Power Magazine article cited above). This is no doubt a big advance from the prior art DC circuit breaker of US patent 3,809,959 (from ASEA before they joined Brown-Boveri to form ABB; this device is still used in current-source converters around the world), but it is not true to say it is the "world's first circuit breaker for HVDC." It is true to say it is more compact and faster than the prior art methods, though I think the story put out by ABB that faster action (2-5 ms versus 50 ms) is crucial to create a workable HVDC grid is debatable (see this post by Gregor Czisch). Faster acting circuit breakers are indeed needed for multi-terminal HVDC based on VSC converters, but not for the older thyristor-based LCC designs (you can read about that in this excellent review by Professor Franck). The prior art ASEA method is widely deployed in HVDC schemes today, to shut down one leg of a bipole HVDC scheme when needed (so that the other leg can still operate as a monopole with ground return in case of a fault on one leg of the scheme). 

ABB's HVDC circuit breaker may not be cost competitive with an HVDC Ballistic Breaker (my invention, see, once I get funding to build one. The use of power electronics requires liquid cooling, and a high degree of redundancy. If I am correct, the cost of ABB's Hybrid HVDC Breakers will be about 25% of the cost of a VSC AC/DC converter station, or about $35/kW 
(AC circuit breakers at 200kV cost ~ $.15/kW for comparison); this is high enough that it will still be impossible economically to place ABB hybrid HVDC circuit breakers between every set of next neighbor power taps on main lines of the supergrid (which may well carry ~30 GW) in the future. The supergrid needs something much less expensive to make full circuit protection (as is routine in the HVAC transmission grid) feasible economically. The Ballistic Breaker is that device.

FYI, here is a video on the ABB hybrid circuit breaker’s operation:

And here is an interview with Claes Rytoft, head of ABB's Power Transmission Group:

Wednesday, October 17, 2012

Presentation at Global CleanTech Meetup in Boston

I had a great time at the Global CleanTech Meetup ( over the past few days. I presented on Ballistic Breakers on Tuesday. This was well received and I got several good investment leads as well.

Wednesday, September 19, 2012

Meeting with China EPRI

C-EPRI is the research arm of China State Grid, focused on HVDC equipment. They are interested in using Ballistic Breakers for multi-terminal HVDC.

Wednesday, August 1, 2012

I am about to receive initial funding for building a Ballistic Breaker prototype

I am determined to over-deliver on the MassCEC grant. I intend to do preliminary experiments with junk electrical equipment; my goal is to demonstrate prototype circuit breakers at several power levels, rather than the one single power level that I promised as a deliverable for the grant. This preliminary scoping can be done for very low cost and will help avoid any serious problems later with the design. I have a "skunkworks" location in mind...confidential for now.

Monday, June 25, 2012

Successful time at TechConnect 2012

I was pleased to make several important connections at the TechConnect conference (my presentation and poster session were on June21). These contacts include folks from Toshiba and the Max Plank Institute. among others. Perhaps the most exciting development was that I met with Google Ventures while I was out West. Google is unique among VCs in that they wanted to hear about both Ballistic Breakers and elpipes (which I have essentially given up on in the US).

My hosts during my stay were Tim and Danielle, who I met on, shown here with one of their rats:

Friday, June 22, 2012

Official Announcement of Mass Clean Energy Center Catalyst Grant Recipients

It is clear from this MassCEC press release that the seven grant recipients were well chosen, and are all promising technologies. I am very grateful to MassCEC for providing my first external funding.

Monday, June 11, 2012

Presentation to the International Symposium on Electrical Insulation 2012

My co-authored paper with Clay Taylor of MSU "Determination of Optimum Resistor Sequence in a Ballistic Breaker" will be presented today by Clayborne Taylor, Junior of Mississippi State University (MSU). I was not able to attend this conference myself, and I am very thankful to Clay for traveling to Puerto Rico to make this presentation.

Wednesday, May 23, 2012

Ballistic Breaker Corp selected to receive a Mass Clean Energy Center Grant

This grant will be my first funding since starting down this road in late 2008. My process started with filing two NYSERDA grant applications and a Round #1 ARPA-E concept paper, then I organized Electric Pipeline Corporation to pursue the elpipe concept in MIT Enterprise Forum's "Ignite Clean Energy" business plan competition (ICE has since joined with the CleanTech Open). Eventually it became clear to me that elpipes (my original concept) are too big to be venture fundable...then I invented Ballistic Breakers in October 2010 and have since pursued development of Ballistic Breaker Corporation as a vehicle to move DC power transmission forward (and to make money & create jobs), as a participant in both the CleanTech Open and MassChallenge in 2011. The initial applications I am pursuing for Ballistic Breakers are in the medium voltage DC (MVDC) area. I am very grateful to Comprehensive Power of Marlborough MA and especially to Frank Jones, President and Founder, for all his support getting to this point. This grant is directed to address a specific Comprehensive Power application involving protection of a large electronic drive for a variable speed motor, similar to that shown in the photograph below. Comprehensive Power will test our prototypes and provide helpful feedback. I believe that Comprehensive Power's participation was instrumental in the success of my proposal, as were the drawings I received from Robert DaSilva of XCraft, Inc., for inclusion in my application and my final presentation May 17, 2012; as shown below. Both Frank Jones and Robert DaSilva will be participants in the execution of this grant.

 In this picture, Roger Faulkner is on the left, Frank Jones (President and CEO of Comprehensive Power) is on the right. We are standing in front of Comprehensive Power's Dynamometer test stand, which is set up here to test >2MW permanent magnet motors (they are tested against one another; one is the motor, the other is the generator). The 1200 volt, 1200 amp Ballistic Breaker I am developing for Comprehensive Power will fit in one of the standard 200X200X800 mm slide-in racks that are behind us in this picture.

email telling me of the award:
 From: "Bernier, Michele" <>
To: "" <>
Sent: Wednesday, May 23, 2012 10:57 AM
Subject: MassCEC Award status: Ballistic Breaker Corporation

Dear Roger,

The MassCEC and MTTC have reached a decision regarding the MassCEC Catalyst Awards.

You have been selected by our reviewers to receive the award of $40,000 for your proposal titled, “Demonstration of Ballistic Breaker™ for 1200 volt, 1200 amp service". Congratulations!

Thank you and congratulations!!
Michele Bernier, M.B.A. 
Commercialization Programs Manager
University of Massachusetts
Office of the President
Suite 400
333 South Street
Shrewsbury, MA 01545

Friday, May 18, 2012

Ballistic Breaker Corp will present at TechConnect World Conference 2012

I will be among 60 innovative early stage companies selected to present at TechConnect World Conference 2012 in Santa Clara. This year, the TechConnect Conference will be co-located with the CleanTech Open National Conference, so I have a double invitation (since I am a 2011 CleanTech Open Alumnus as well).

Thursday, May 17, 2012

MassCEC Grant Application Final Presentation

Today I made my final pitch in pursuit of a $40k "Catalyst Grant" from the Mass Clean Energy Center. I proposed in my application to use the money to fabricate a 1200 volt, 1200 amp Ballistic Breaker for an initial application with Comprehensive Power (Customer #1) of Marlborough, MA. Frank Grant, founder & President of Comprehensive power has agreed to test the breaker and to provide other assistance.

Monday, May 14, 2012

Ultralight Startup Pitch for Ballistic Breaker Corp

I made a pitch in this unique event today. Here is a practice pitch I made while preparing for this rather unusual format event. The judges provided valuable feedback, and I got an exciting connection with Shell GameChanger through one of the judges (Dr. Willem Albert Rensink).

Wednesday, March 21, 2012

I submitted a paper for ISEI 2012 on the Ballistic Breaker

This co-authored paper with Research Professor Clayborne Taylor, Jr. from Mississippi State University, "Determination of Optimum Resistor Sequence in a Ballistic Breaker"  will be presented at the

2012 IEEE International Symposium on Electrical Insulation (ISEI)

 I have included here both my first draft of this paper and the final submitted document, that eliminates some of what I wrote to give my co-author Clay Taylor some room to fit in his modeling results.

Saturday, March 3, 2012

Successful ARPA-E Showcase Display Table

I was selected for the ARPA-E Technology Showcase. It was an honor to share the space with so many great innovators. I had a poster, a Power Point looped presentation and this avi file running continuously.

Tuesday, February 7, 2012

Patent Submitted (US utility patent) on Ballistic Breakers

I submitted a patent application on Ballistic Breakers™  November 30, 2011, which is now abandoned. I submitted a much-refined patent application yesterday. The linked document is an excerpt from my (52 page, not including the 20 figures) patent application; the full application is proprietary for now, only available under NDA and/or to be shared with serious candidate investors. I am very pleased with the results, however. I plan to submit a paper soon that will reveal more information about what is in the patent (but not everything!).

Friday, January 13, 2012

Ballistic Breaker selected for 2012 ARPA-E Energy Innovation Summit Technology Showcase

I applied three times for ARPA-E funding from the US Department of Energy (twice for elpipes, once for Ballistic Breakers). Though those efforts were unsuccessful, my selection for the ARPA-E summit is a nice recognition that my concepts are important.

From: Sarah Wenning <>
Sent: Friday, January 13, 2012 2:41 PM
Subject: 2011 ARPA-E Technology Innovation Showcase Application Notification

Reference Showcase Submission Number: 114
Dear Roger Faulkner:
Congratulations!  Your submission to the 2012 ARPA-E Energy Innovation Summit Technology Showcase has been approved.  Our participating government, investment, and corporate partners are eager to view your technology. 
The Technology Showcase Receptions will take place on:
·         Monday, February 27th:  4:30 pm – 7:30 pm
·         Tuesday, February 28th:  12:30 pm – 1:30 pm, 5:00 pm – 8:00 pm
·         Wednesday, February 29th:  12:50 pm – 2:00 pm
*Showcase times are subject to change. Please refer to the website for updates.