The field of the invention relates to the mounting and the support of energy storage cell canisters within a multi-cell energy storage module.
A multi-cell energy storage module (e.g., ultracapacitor module) may include a plurality of energy storage cell canisters (e.g., ultracapacitors) electrically connected together in series, physically end-to-end, to form a higher-voltage module. The cylindrical energy storage cell canisters may be electrically connected by means of rectangular bus bar interconnections with holes at each end to fit over circular end terminals of two energy storage cell canisters. A problem that has occurred in some of these multi-cell modules is that the energy storage cell canisters were not adequately supported relative to each other (i.e., not precisely fixed relative to each other). As a result, relative movement of the energy storage cell canisters caused the bus bar interconnections to flex. Over time, the flexing bus bar interconnection compromises the interconnection integrity, resulting in a high interconnection resistance. The high resistance lowers the efficiency of the energy storage and causes excessive heat generation that can destroy or shorten the life of the energy storage cell canisters. Similarly, excessive heat generated by inner interconnections between energy storage cell canisters lowers the efficiency of the energy storage and destroy or shorten the life of the energy storage cell canisters.
Accordingly, an aspect of the present invention involves a system and a method to support and maintain a precision location of each energy storage cell canister within a multi-cell energy storage module, and to cool the energy storage cell canisters and interconnections therebetween.
Another aspect of the invention involves a system for mounting and cooling energy storage cell canisters within a multi-cell energy storage module. The system includes a plurality of inner interconnections to electrically connect the energy storage cell canisters end-to-end in strings of energy storage cell canisters; a plurality of bus bar interconnections to electrically connect the strings of energy storage cell canisters; and a plurality of cooling line separator inserts to position and support the plurality of inner interconnections for positioning and supporting the storage cell canisters, the plurality of cooling line separator inserts including fluid transfer lines for carrying cooling media therethrough for removing heat from the plurality of inner interconnections.
A further aspect of the invention involves a multi-cell energy storage module including a plurality of energy storage cell canisters; and a system for mounting and cooling the energy storage cell canisters having multiple fluid transfer lines for carrying cooling media therethrough for removing heat from the plurality of energy storage cell canisters.
The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of this invention.
With reference to
In the embodiment shown, the multiple-cell energy storage module 110 is a Maxwell MC BMOD Energy Series 48V BOOSTCAP® brand Ultracapacitor Module made from Maxwell BOOSTCAP® brand ultracapacitor energy storage cell canisters. The module 110 includes eighteen (18) cylindrical energy storage cell canisters (i.e., cells, cans) 120 arranged in three rows of six energy storage cell canisters 120. In alternative embodiments, the invention is applied to other multiple-cell energy storage modules.
The energy storage cell canisters 120 are aluminum cylindrical cans approximately 2.27 inches in diameter and 6 inches in length with terminals 130 protruding from each end of the energy storage cell canister 120 for the electrical terminal connection. The ultracapacitor energy storage cell canister 120 is polarized with the negative side terminal 132 connected to the body 133 of the energy storage cell canister 120 and the positive side terminal 131 insulated 135 from the body 133 of the energy storage cell canister 120. In an alternative configuration of the energy storage cell canister 120, the terminals 130 are female threaded holes wherein male threaded studs are screwed into the holes to provide the protruding connection terminal.
The energy storage cell canisters 120 are electrically connected by means of thin, rectangular bus bar interconnections 140, 150 with 0.54 inch diameter holes at each end to fit over the circular end terminals 130 of two energy storage cell canisters 120. Because the energy storage cell canisters 120 are spaced wider apart in a center 160 of the module 100, the bus bar interconnections 150 connecting across two middle columns 170, 180 of energy storage cell canisters 120 are 2.85 inches long whereas the other bus bar interconnections 140 are only 2.44 inches long. Other embodiments may have connection and separation patterns that differ from those shown in
During the assembly process the bus bar interconnections are heated to expand the holes, placed over the energy storage cell canister terminals, and allowed to cool for a shrunken press fit. The exterior 133 of the energy storage cell canister 120 is electrically active, being connected to the negative side 132 of the energy storage cell canister 120.
Separator inserts 190, 200 are made of high-temperature, ⅝-inch thick, electrically insulating nylon plastic. The separator inserts 190, 200 include incurved lateral sections 210, 220, which are machined into the nylon separator inserts 190, 200, to match the outer curved exterior of the energy storage cell canisters 120. The location of the incurved lateral sections 210, 220 are determined by the desired position of the energy storage cell canisters 120 within the module 110. Holes 230, 240 are drilled into the separator inserts 190, 200 to provide for wiring access to circuit boards 250, 260 (
Two three-can separator inserts 190, 200 are installed substantially perpendicular to the cylindrical axis of the energy storage cell canisters near the ends of the energy storage cell canisters (front, back of the module 110) in the five spaces between the six columns 270 of energy storage cell canisters 120, for a total of 10 separator inserts. As shown in
With reference to
In a further embodiment, the module 110 includes a mounting sheet or mounting plate that includes cut outs and/or holes to support and position the energy storage cell canisters 120 within the sealed module 110.
In the embodiment shown in
The circuit boards 250, 260 contain equalization and balancing circuits for the energy storage cell canisters 120 connected in series within the module 110. In an alternative embodiment, one or more of the circuit boards 250, 260 also contain communication circuits that report the module status external to the module 110. To connect the balancing circuits to the end terminals 130 of the energy storage cell canisters 120 wires pass through the holes 230, 240 in the separator inserts 190, 200 and are riveted to the bus bar interconnections 140, 150 through predrilled holes, not shown.
A method of manufacturing a multi-cell energy storage module 110 and/or retrofitting an existing multi-cell energy storage module 110 includes, first, shaping the separator inserts 190, 200 from ⅝-inch thick nylon plastic separator inserts. Each nylon plastic block is machined to the proper dimensions to fit the energy storage cell canisters 120 and their position within the module 110. Next, the electrical balancing and equalization circuits and circuit boards 250, 260 are manufactured. The nylon separator inserts 190, 200, supports for the circuit boards 250, 260, and the circuit boards 250, 260 are placed in the spaces between the columns 270 inside the module 110. During the installation of the circuit boards 250, 260, the wires from the circuit boards 250, 260 are fed through the holes 230, 240 in the nylon separator inserts 190, 200 and riveted to the interconnection bars 140, 150. In alternative embodiments, materials other than hard nylon plastic are used and/or other methods of forming the material to the desired shape are used.
The separator inserts 190, 200 rigidly support the energy storage cell canisters 120 in exact cell position relative to each other. A rigid and exact cell position is necessary to maintain the integrity and low electrical resistance of interconnecting bus bar interconnections 140, 150. Also, consistent spacing has to be maintained for active balance circuit printed circuit boards (PCBs) to fit properly between the energy storage cell canisters 120.
With reference to
Like elements of the multiple-cell energy storage module 390 and of the multiple-cell energy storage module 110 described above will be described below with the same reference numbers.
Although the multi-cell energy storage module 390 is shown as being rectangular, in alternative embodiments, the support and cooling system”) 400 is applied to any pack topographic configuration (e.g., flat, rectangular, cylindrical, rectilinear, curvilinear).
Referring to
The outer diameter 480 of the disc 470 is greater than the outer diameter of the cell canister 120 and is covered with a thin material 490 that is heat conducting, but electrically insulating material. Therefore, the cell canister 120 is electrically isolated and thermally connected to the cooling line separator support bars 410 through the interconnection discs 470.
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In the embodiment shown in
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The cooling line separator support insert 410 is a longitudinally elongated aluminum extrusion and has a generally triangular cross-section. Each cooling line separator insert 410 includes three circumferentially spaced elongated concave sides 530 and elongated narrow flat faces 540 to form a substantially hexagonal, elongated configuration. The circumferentially spaced elongated concave sides 530 have a radius to conform to the outer surface 490 of the inner interconnections 470 to extract heat therefrom. The cooling line separator support insert 410 includes a fluid transfer cavity or line 550 for carrying cooling media therethrough for coolant flow and heat dissipation.
In alternative embodiments, the cooling line separator support inserts 410 are continuous along the entire row of energy storage cell canisters 120 and/or have a length to match the thickness of the end interconnection discs 471, 472 so as not to interfere with the bus bar connections. Because the cooling line separator inserts 410 do not extend beyond the interconnection discs 471, 472 there must be a coolant flow tube that structurally and thermally connects to the cooling line separator support inserts 410 and the outside end plate 420, 430.
In alternative embodiments, the cooling line separator support inserts 410 have various interior passage shapes for the coolant flow.
In other alternative embodiments the cooling line separator inserts 410 may have different shapes 411 (
With reference to
In the embodiment shown, each row of energy storage cell canisters 120 is surrounded by up to six cooling line separator inserts 410 that extend through the end plates 420, 430 to an external heat rejection/removal loop. The support and cooling system 400 includes cooling line separator inserts 410, an inlet end plate 420, an outlet end plate 430, a radiator 440, fluid transfer lines 450, and pump 460. The external heat removal loop includes the fluid transfer lines 450, the radiator 440, and the pump 460.
The multiple-cell energy storage module 390 is air-tight and water-tight to protect the terminal connections from shorting (in the event of a submersion) and gradual corrosion from moisture or other chemicals that may be present in the cooling flow. Additionally, toxic gases released during any fault condition that would cause cell leakage or rupture are totally contained within the multiple-cell energy storage module 390.
Optionally, any of the embodiments include a paste or gel on the threaded connections to aid in electrical and thermal conductance, and/or aid in resistance to corrosion of the connection and loosening of the connection.
Some of the advantages of the support and cooling system 300 include the formation of a support structure that provides sufficient stiffness and securement in the assembly and for the strings of energy storage cell canisters 120 to prevent the interconnects from bending, deteriorating and causing increased internal resistance, and to prevent electrolyte leaking. Also, the support and cooling system 300 removes heat from the inner interconnects 470, providing an effective way to cool the entire associated energy storage cell canister(s) 120. The system 400 transfer heat away from the interconnection discs 470 through the cooling line separator support inserts 410, and out of the multiple-cell energy storage module 390 through the external heat rejection/removal loop.
The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles described herein can be applied to other embodiments without departing from the spirit or scope of the invention. Thus, it is to be understood that the description and drawings presented herein represent a presently preferred embodiment of the invention and are therefore representative of the subject matter which is broadly contemplated by the present invention. It is further understood that the scope of the present invention fully encompasses other embodiments that may become obvious to those skilled in the art and that the scope of the present invention is accordingly limited by nothing other than the appended claims.
This patent application is a continuation-in-part application of U.S. patent application Ser. No. 11/459,754 filed Jul. 25, 2006, which is a continuation-in-part application of U.S. patent application Ser. No. 10/951,671 filed Sep. 28, 2004, which is a continuation-in-part application of U.S. patent application Ser. No. 10/720,916 filed Nov. 24, 2003, which is a continuation-in-part application of U.S. patent application Ser. No. 09/972,085 filed Oct. 4, 2001, now U.S. Pat. No. 6,714,391. This application claims the benefit of these prior applications and these applications are incorporated by reference herein as though set forth in full.
Number | Date | Country | |
---|---|---|---|
Parent | 11459754 | Jul 2006 | US |
Child | 11535433 | Sep 2006 | US |
Parent | 10951671 | Sep 2004 | US |
Child | 11535433 | Sep 2006 | US |
Parent | 10720916 | Nov 2003 | US |
Child | 11535433 | Sep 2006 | US |
Parent | 09972085 | Oct 2001 | US |
Child | 11535433 | Sep 2006 | US |