Note: Descriptions are shown in the official language in which they were submitted.
CA 02762078 2011-12-16
1
FIELD
The invention pertains generally to electrical wiring, connectors, terminals
and boxes, and
particularly to those devices for use with solar photovoltaic modules and
related electrical systems.
BACKGROUND
Solar photovoltaic modules (or panels) produce DC electrical power that is
collected through
wiring commonly attached to the back of the module. Multiple modules may be
connected together
to produce greater power. A plurality of modules connected in this fashion is
commonly referred to
as an array. To facilitate the rapid assembly of arrays, modules are commonly
equipped with locking
quick-connect electrical fittings. Among many such designs, Tyco and MC4
connectors are
common.
Due to limitations, both physical and electrical, large arrays are often made
up of several smaller
arrays known as strings. Strings are then wired together electrically to
produce the array.
The division into strings may be related to the physical layout of the array,
for instance, when
modules have to be separated to fit around an air conditioner unit on a roof.
In this case
weatherproof enclosures known as junction boxes or chock boxes can be used to
combine the wiring
of the strings back together.
It is also common to use strings to keep the electrical wiring below
prescribed voltage or current
limits, or to limit short-circuit current flow. To protect against this
possibility, the array is divided
into strings and the strings are then isolated using circuit protection
devices such as fuses or circuit
breakers. These are commonly found in load centers, fuse boxes or combiner
boxes; herein
collectively referred to as combiners.
Common examples of junction boxes and combiners are not designed specifically
for use in the
solar industry. Generally, they are designed to connect using terminal block,
wire nuts ("Marettes")
or similar systems designed to connect to bare wire. Connecting a string to
the combiner is thus a
time consuming process, requires several tools, additional parts, and
generally has to be carried out
by a licensed electrician.
If the array requires more strings than a given combiner supports, multiple
combiners are wired
together. Known combiners lack any system for rapid interconnection, and labor-
intensive wiring
techniques like those for string connection are needed. Larger combiners with
more terminals are
also available, but often impractical due to their size, cost, and the need to
run the wiring from the
strings to the central location of the combiner.
Accordingly, what is desired is an improved junction/combiner system for the
rapid assemblage
of strings and arrays. Ideally, no tools would be needed to connect the string
to the combiner, or
combiners to each other. The resulting modular combiner design could support
any number of
strings through such assembly Additionally, such a device would ideally
combine several common
functions currently handled in separate electrical boxes or devices, including
the electrical
connections (junction box), circuit protection (combiner box), and optionally
include means to
identify faults and isolate a string from the array when desired (disconnect
switch).
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2
RELATED ART
It is in the known prior art to describe electrical combiner systems allowing
the connection of
arbitrary electrical equipment, as well as examples with built-in circuit
protection devices. Generic
devices like these are widespread in the solar industry. Bespoke systems
equipped with common
module connectors are also known, but not common. All of these exhibit the
problems noted above,
as they are not designed for rapid interconnection to form arrays.
Examples of combiner systems with customized construction intended for use in
the renewable
energy industry are also known. US Patent Application 10/612,873, Brown et al
describes a
wiring system and combiner box assembly for the rapid connection of several
modules into a string.
However, the combiner system is a fixed size, and does not allow modular
construction of an array
of arbitrary size. Moreover, the combiner and string wiring is all of custom
design, and does not
allow for direct connection to known module wiring.
US Patent Application 11/379,728 by McClintock et al discusses a combiner box
for use in
the solar industry intended to aid with fault detection. Each combiner is
designed to connect to
multiple strings in order to identify which is at fault. It mentions improved
installation time in the
context of separately wiring monitoring consoles for the fault detection
system. The terminals are all
of conventional design intended for attachment to bare wire on the inside of
the enclosure.
US Patent Application 12/657,069 by Fornage et all describes a connection
system for
individual solar modules to associated inverters. These are combined using a
conventional load
center.
US Patent Application 12/468,984 by Sok et al describes a solar array equipped
with
combiner boxes including DC-DC power converters. The combiners are themselves
combined in
parallel to form an array, using conventional combiners.
US Patent Application 12/942,750 by Schripsema describes a combiner system
with built-
in fault monitoring. Conventional wiring and terminals are used throughout.
US Patent Application 11/379,728 by McClintock et al describes a combiner
system of
conventional design with built-in fault monitoring and communications.
Conventional wiring and
terminals are used throughout.
US Patent Application 12/288,956 by Lewis and Herzog describes a separate
fault
detection system that wired into the array in advance of conventional
combiners.
US Patent 7987641 by Cinnamon describes mechanical details of a module
mounting system.
Application US 12/796,466 by Cinnamon et al expands on US 7987641 with the
description of a
new electrical system intended for use with the described mounting system.
This includes a junction
box with built-in quick-connect terminals. This is intended for use only with
this mounting system,
and lacks the ability to connect the junction boxes together, illustrating
conventional conduit wiring.
US Patent Application 12/714,855 by Solon describes a system of wiring
harnesses that
include in-line fuses for string protection. They are shown with conventional
combiners.
US Patent Application 12/582,367 by Luebke et all describes a system of
advanced string
protection devices, offering protection from arc faults in addition to more
common faults like shorts.
Such systems are described as possibly being integrated in conventional
combiners.
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3
SUMMARY OF THE INVENTION
The present invention describes an electrical combiner and junction box of
unique construction
intended to simplify the assembly of a plurality of solar modules into arrays.
The combiner
includes, at a minimum, connectors for attachment of electrical equipment, and
connectors for
attachment between similar combiners to form a common electrical system.
According to the present invention, solar modules can be connected to the
combiners directly,
quickly, safely, and without tools. This is accomplished through the use of
quick-connect terminals
like those found on the solar modules.
According to the present invention, such combiners may also be connected
together to form
modular combiner systems supporting larger arrays of multiple strings of
modules. This task may
also be completed quickly, safely and without tools. This is accomplished with
quick-connect
terminals like those on the modules, or similar connectors more suitable for
forming multi-
conductor electrical connections.
According to the present invention, the resulting array may be easily
connected to external
electrical equipment.
According to the present invention, the safety of connection and disconnection
of modules from
strings may be improved, as connections are of the protected type, with no
visibility of live
conductors, and all terminals protected by insulated mechanical structures.
Embodiments of the present invention generally consist of combiner boxes with
one or more
sets of quick-connect terminals found on solar modules for connection to the
string, and one or
more quick-connect fittings for connecting combiners together into arrays.
Embodiments may also
include circuit protection devices such as circuit breakers, fuses or
disconnection switches.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a typical solar array consisting of one or more
photovoltaic
modules connected together using DC wiring to form a string, and multiple
strings to form an array;
FIG. 1A is a block diagram of a system of one or more photovoltaic modules
connected to
individual inverters and AC wiring to form a string, and strings to form an
array;
FIG. 2 is a schematic diagram of one possible embodiment of the present
invention;
FIG. 3 is diagram of one possible embodiment of the present invention intended
for junction
box duties connected to generic electrical systems, which may include solar
modules;
FIG. 3A is diagram of one possible embodiment of the present invention
intended for
combiner box duties and direct connection to solar modules with the MC4 style
connector;
FIG. 3B is diagram of one possible embodiment of the present invention
intended for
combiner box duties and direct connection to inverters with the Enphase M190
style connector;
FIG. 3C is diagram of one possible embodiment of the present invention
intended for
combiner box duties that include an indicator lamp and disconnect switch;
FIG. 3D is diagram of one possible embodiment of the present invention
intended to combine
together the wiring of multiple combiners ("recombiner"), which includes a
multi-pole disconnect
switch and heavy-duty terminals for interconnection;
FIG. 3E is a diagram of a cabling assembly suitable for rapid interconnection
of boxes as
above;
FIG. 4 is a block diagram of a DC solar array similar to the one illustrated
in Fig. 1, but
implemented using the present invention;
FIG. 4A is a block diagram of an AC solar array similar to the one illustrated
in Fig. IA, but
implemented using the present invention;
FIG. 4B is a block diagram of a larger solar array constructed of several
arrays as in Fig. 4
interconnected ("recombined")using the present invention;
FIG. 5 is a more detailed illustration of a sample assembled module string
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4
DETAILED DESCRIPTION OF THE INVENTION AND DRAWINGS
Solar arrays are constructed of a number of solar modules connected together
electrically to
form a single larger system, the array. FIG. 1 is a block diagram of a typical
solar array consisting
of one or more strings of one or more photovoltaic modules each. This diagram
shows only one of
a myriad of possible configurations, and those familiar in the art will
recognize this diagram is in no
way limiting.
The array 100 consists of a plurality of photovoltaic modules 101(1)...101(0)
connected
together using electrical wiring 102(1)...102(o). The array is further
subdivided into a plurality of
strings 104(1)...104(n) of modules connected using common wiring. To bring the
wiring from
both ends of the strings to a common point, strings may use extension cables,
or "home runs",
103(1)...103(n).
Strings 104(1)...104(n) may be connected together through DC combiners 105 to
form the
array 100. Multiple combiners may be used, depending on the number of
terminals in the
combiner 105. In conventional systems, these combiners require manual assembly
of the
connections and normally support multiple strings in a single enclosure. Home
runs may have to be
lengthy in order to reach the location of a shared combiner, which may lead to
energy losses in the
wiring. Additionally, if multiple combiners 105 are used, inter-combiner
wiring has to be installed
using time consuming techniques.
The output of the array 100 is further isolated with optional load centers,
disconnects and other
safety systems 107, as mandated by local electrical and building codes. The
output is then sent to
the load 108. In "grid-tie" systems, the output of the array is run to an
inverter as load 108.
Modern microelectronics has allowed the inverter to be reduced in size until
it is suitable for
mounting on an individual module. In such systems, the inverter is commonly
referred to as a
"micro-inverter", as typified by designs from Enphase Energy and Enecsys.
Unlike the example
illustrated in Fig. 1 which uses DC power throughout, when using micro-
inverters the electrical
wiring carries AC power, which has certain advantages. As is the case in DC
arrays, wiring
limitations often demand that the array be split into strings.
FIG. 1A is a block diagram of a typical solar array 200 consisting of a
plurality of modules
201(1)...201(o) connected to individual inverters 202(1)...202(o). The
inverters are connected to
each other along the AC wiring bus 203(1)...203(n) to form strings
204(1)...204(n). Inverters
202(1)...202(o) are illustrated installed on the back of the modules, as is
common, but not
required.
Strings 204(1)...204(n) are connected through AC combiner or load center 205
along the AC
electrical bus 206 to form the array 200. If multiple combiners are needed,
they are connected in
parallel along AC bus 206. The output of the array along AC bus 206 is further
isolated with
optional load centers, disconnects and other safety systems 207, and then sent
to an AC load 208.
The AC load 208 is commonly a power distribution panel or public electrical
grid.
FIG. 2 is a schematic diagram of one possible embodiment of the present
invention, combiner
box 300. A module string 301 connects to the module terminals 302 and the
associated grounding
wire to grounding point 303. Upstream terminals 305 and downstream terminals
306 are
connected to form an electrical bus 308. Module terminals 302 are connected in
parallel to the
electrical bus 308 through optional circuit breaker 310 and indicator lamp
309, as well as optional
disconnect switch 311. The use of a single positive-indication circuit breaker
310 can fulfill the
duties of 309, 310, and 311.
The following figures illustrate particular embodiments of the apparatus of
the present patent in
a variety of forms customized to allow rapid interconnection to a variety of
devices commonly used
in the solar industry. All of these combine the features of modularity of
interconnection and rapid
CA 02762078 2011-12-16
assembly of strings and arrays. These illustrations should not be considered
limiting; any similar
device featuring rapid connection and modular assembly is a part of the
present invention.
FIG. 3 is a semi-diagrammatic view of one possible embodiment of the present
invention 400
illustrating its basic mechanical layout.
Electrical terminals 401, the downstream terminal 401(D) and upstream terminal
401(U), may
be connectors of any suitable quick-connect design. A wide variety of suitable
connectors using
cam-lock, bayonet and twist locking systems are suitable. The choice of
connector will be subject to
local electrical codes and common usage. This embodiment is illustrated with
three-pin screw-lock
terminals with an alignment "key".
The wiring to the electrical equipment being added to the bus formed along 401
is through the
compression fitting 402. This embodiment would be suitable for connection to
arbitrary electrical
equipment, not just modules, but other equipment such as monitoring devices.
Optional indicator LED 403 is connected to the internal circuit breaker or
fuse holder in order
to indicate a tripped condition. In the case of push-button or other visible
breakers, lamp 403 is
redundant. Alternately, circuit breaker/fuse holder may include a built-in
indicator lamp, in which
case an optically clear window in the proper location may be used to replace
lamp 403.
Optional flanges 404 are used to protect terminals 401 and compression fitting
402 from
mechanical damage, as well as providing attachment points for electrical
conduit fittings. These are
illustrated being shorter than those normally found on PVC T-junction boxes to
allow easy access to
the fittings and terminals These are illustrated as threaded fittings suitable
for 2-inch PVC conduit,
large enough to pass common fittings used in the industry. As all of the
fittings used in this
embodiment are suitable for unprotected outdoor use, flanges 404 are provided
only for
convenience.
FIG. 3A is a partial diagram showing the basic embodiment 400 shown in FIG. 4
customized
for use with MC4 DC connectors. This embodiment replaces the compression
fitting 402 with male
405(M) and female 405(F) MC4 connectors and uses C-style grounding lug 406 for
chassis
grounding. This embodiment is also suitable for use with Tyco or other
standard connectors in place
of MC4 connectors. As panel-mount connectors are generally fragile, an
alternate embodiment
would retain the compression fitting 402 and use short lengths of wire to
attach the MC4
connectors, as shown in the inset in the lower right.
Optional disconnect switch 407 is located on the back of the box. Mounting
this on the lid is
possible, but would make maintenance access more difficult. If the fuse or
circuit breaker can be
reset from the outside of this case, switch 407 and LED 404 can be easily
relocated to the box top.
FIG. 3B is a partial diagram showing the basic embodiment 400 shown in FIG. 3
customized
for use with inverters embedded in the strings (micro-inverters). This
embodiment replaces the
upstream and downstream terminals 401 with multi-pin connectors 408 suitable
for use with split-
phase or three-phase power, 408(U) and 408(D). In this embodiment, compression
fitting 402 has
been replaced with Enphase Ml 90 female connector input terminal 409. These
terminals are
robust, suitable for direct mounting as in this embodiment. Terminal 409 can
be replaced by any
similar connector, such as those used on Enecsys or SMA micro-inverters.
The electrical limitations that require arrays to be broken into strings may
also apply to the
wiring used in the electrical bus connecting the strings together. In these
instances, the electrical bus
is further divided, isolated using circuit protection systems in larger
combiners, and then combined
into an array using heavier gauge electrical cabling between these combiners.
Often the electrical
cabling is internal to a larger combiner. In these instances combiners are
sometimes referred to as
"recombiners".
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FIG. 3D shows another possible embodiment of the current invention 400
modified for
recombiner duties, offering the same advantages of quick assembly and modular
construction. It
differs only in mechanical construction and the size and power rating of the
electrical components.
Combiner 400 includes one or more bus terminals 410(1)...410(n) of type
similar to 401 or 408,
built-in multi-pole disconnect switch 411 and optional indicator lamps
412(1)...412(n).
Interconnection between examples of this embodiment are provided by the heavy-
duty bus
terminals 414(U) and 414(D), illustrated in this embodiment using individual
cables for each
phase of power and connecting using Cam-Lock connectors widely used in
industry.
The following are examples of installations of solar arrays in accordance with
the method of the
present invention. Anyone of ordinary skill in the art will recognize that
there could be any number
of modules, strings and electrical arrangements of the present invention, and
these diagrams should
be in no way considered limiting.
FIG. 4 is a block diagram of an array similar to Fig. I constructed to produce
array 500 using
the present invention. Strings 104(1)...104(m) are individually connected to
DC combiners
501(1)...501(o) of the type illustrated in Fig. 3A. Combiners 501(1)...501(m)
are interconnected
using quick-connect bus cabling to form DC bus 502. The free end of bus 502 is
closed off with
terminator cap 503, while the load end is connected with home run cable 504
along the same bus.
FIG. 4.4 is a block diagram of an array similar to Fig. IA constructed to
produce array 500
using the present invention. Strings 204(1)...204(m) are individually
connected to AC combiners
505(1)...505(o) of the type illustrated in Fig. 3B. Combiners 505(1)...505(m)
are interconnected
using quick-connect bus cabling to form AC bus 506. The free end of bus 506 is
closed off with
terminator cap 507, while the load end is connected with home run cable 508
along the same bus.
FIG. 4B is a block diagram of a large array constructed of multiple examples
of arrays 500(1)
...500(n) as in FIG. 4, interconnected with array-connection combiners 509 as
illustrated in FIG.
3D. Arrays are connected to combiners 509(1)...509(n) through bus cables
510(1)...510(n) and
to each other using bus cables 511(1)...511(n), the last of which is connected
to terminating safety
devices 512 and then to the load 513.
The following are illustrations of possible array layouts assembled using the
present invention. In
general, assembly will progress with the installation of the modules onto a
mechanical support
structure commonly referred to as "racking". If a micro-inverter or power
optimizer device will be
used, this is commonly installed at the same location as the modules. The
modules, or their
inverters, are then wired together using provided cabling. Grounding systems
are also installed,
normally using separate wiring attached to grounding lugs screwed into the
frames of the modules
and racking.
Further assembly using the present invention would then progress by connecting
the free ends of
the module cabling to the quick-connect fittings on the combiner. Combiners
are then
interconnected to each other using bus cabling attached to the associated
terminals. The first
combiner within any section of the array, the combiner furthest from the load,
will have an open
interconnection terminal that is closed off with a cap. The last combiner
within any section of the
array, the combiner closest to the load, will then be connected to a "home
run" cable for connection
to arbitrary electrical equipment, or another bus cable if it is to be
connected into a larger array-of-
arrays.
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7
FIG. 5 illustrates the construction of an array 500 using the present
invention. Strings 104(1)
...104(m) are individually connected to DC combiners 501(1)...501(o) of the
type illustrated in
Fig. 3A. Combiners 501(1)...501(o) are interconnected using quick-connect bus
cabling to form
DC bus 502. The free end of bus 502 is closed off with terminator cap 503, the
load-side end of
DC bus is connected to arbitrary safety systems, and then to the load.
CA 02762078 2011-12-16
Background and terminology
Solar photovoltaics, or simply "PV", is the field of directly converting
sunlight into
electrical power. This typically occurs in the "solar cell", a semiconductor
device with
wiring for power collection.
Individual solar cells produce little power, so in practice many cells are
connected
together to form a "solar panel", or "module". Modules encapsulate the cells,
offering
mechanical protection from the elements. The cells are wired to each other in
the
module and exit into a "junction box" or "combiner box" on the back of the
module.
As it is that a single cell is generally not useful by itself, modules are
generally too
low power to be used alone. Where cells are combined into modules, multiple
modules
are typically combined into larger systems known as "solar arrays", or simply
"arrays".
To facilitate easy interconnection of the modules into arrays, wires lead from
the
junction boxes on the panels to quick-connecting electrical terminals at the
end of the
wires. Simply snapping these terminals together can interconnect modules into
an
array. For legal reasons, these terminals are commonly mechanical-locking
designs
that require special tools to separate.
It should be noted that the terms "panel", "module", "cell" and "array" are
being
used in their modern sense. There are many patents that refer to the
electrical
interconnection of solar arrays, but are in fact referring to solar cells. See
US 4334354
as an example. Similarly, the term "junction box" likely refers to the
connections on
the back of the panel, not to external connectors for module strings. See US
12/988,411 as an example.
The problem
The wiring used on the modules cannot handle an arbitrary amount of power.
Most common module designs use 10 gauge copper wiring, which limits any single
run to between 15 and 20 panels before the combined power reaches the limits
of the
cabling. Connecting more modules together risks an over-current situation.
In order to build larger arrays, the array is broken down into a series of
"strings"
of 10 to 15 panels. Strings are then connected to each other to form the
array.
Strings must be isolated from the others in order to prevent current from one
string flowing into another and causing an over-current condition. This is
normally
accomplished with one of a number of common electrical devices, known as load
centers, junction boxes or combiners. These should not be confused with the
junction
boxes found on the panels themselves.
As these devices are not designed specifically for the solar industry, they
lack the
quick-connect fittings used on the modules. To connect a string to one of
them, the
existing connectors must either be cut off, or a second set of connectors with
"free
ends" has to be added. In either case the bare wires have to be connected on
the
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inside of the isolation device. For legal reasons, handing bare wire is
normally only
allowed by licensed electricians.
Then if more than one such box has been used, which is the common case, the
boxes must be wired to each other using similar methods. In our experience,
this
wiring represented a significant amount of the total time needed to install
the array.
Additionally, this was typically very costly in terms of parts and labor.
A system that allows rapid, safe and inexpensive interconnection of strings
into
arrays is an obvious need in the industry Yet an extensive product search
turns up
nothing of the sort. The only "solution" on offer were large combiner boxes
with
many terminals inside, so that all the wiring could be done at a single spot.
The
downside of this approach is that all of the string wiring must be run to the
location of
the box, and both the box and such cabling is very expensive.
In any event, all known junction and combiner boxes on offer -large and small-
use generic electrical terminals for bare-wire connection. These are generally
products
used in other markets being re-purposed without any modification.
The field of this invention
The invention proposed in this application is a solution to the problem of
assembling modules into strings and strings into arrays, and doing so quickly,
without
the need for an electrician, and in most cases without the need for tools.
It does this primarily through the use of quick-connect electrical terminals
connecting both the modules, and just as importantly, the combiners. Systems
for
rapid interconnection of combiners are not known in the state of the art, or
in
industry
The invention also combines together several formerly separate devices into
one
box. This has the advantage of reducing the parts count of the system as a
whole, and
further easing installation.
The combiner also incorporates all needed circuit protection systems, and may
also include additional electrical hardware used in common installations, like
disconnection systems and fault monitoring.
The combiners are designed to be as small as possible, which allows their
mounting on the array itself. This eliminates any extra cabling that might
otherwise be
needed to connect the strings to a remote combiner box.
The simple act of assembling the system completes many separate stages of
installation and wiring otherwise required.
Preliminary search
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Examining Canadian, US and WIPO Gold patent databases turns up a number of
patents and applications describing electrical connections in the PV field,
the majority
of which can be separated into several broad categories:
1)Descriptions of the wiring of cells into a module
2)Descriptions of the junction box on the back of the module and the wires
connecting to them
3)Descriptions of the connectors at the end of the wires that connect to
adjacent
modules
None of these categories have applicability to the present invention. However,
there are two additional categories that are closer in concept:
4)Descriptions of panel mounting systems that sometimes also describe the
electrical interconnections between panels
5)Combiner boxes intended to help isolate electrical faults
Only patents that fall into category 4 or 5 have any bearing on the present
patent
application, and an extensive search of these fails to turn up any concepts
specifically
dedicated to the problem as outlined above.
Searching the CIPO online database for Canadian patents including "solar
panel"
returns 122 patents, the vast majority of which refer to the panel as part of
some
other assembly, like roadway lighting, or describe solar heating systems. Of
those that
remain, only the following Canadian patents discuss solar PV arrays and their
interconnection:
2574659, 2475524, 2472548, 2701864
2703324, 2695754, 2542672, 2542672
None of these, however, discuss electrical issues except in passing. 2542672
implicitly includes electrical interconnection of modules, but in a way that
can only be
used with the unique solar panel system described within. None of these
patents even
mentions the problem the present invention is attempting to solve.
Examining the US patent database turns up many more relevant hits on concepts
that fall into category 4 and 5.
A few patents describe combiner systems and are clearly similar to the present
invention. These include:
10/612,873
US Patent Application 10/612,873, Brown et al describes a wiring system and
combiner box assembly for the rapid connection of several modules into a
string. The
Background section specifically talks about the need for an electrician to
handle the
wiring of the system. This invention does address at least some of the
problems
considered in the present invention. However, this system uses custom
connectors
throughout the system, and is combined in a single combiner box, whereas the
present
CA 02762078 2011-12-16
invention uses standardized connectors throughout, and allows modular
construction
of the combiners from individual building blocks.
12/942,750
US Patent Application 12/942,750 by Schripsema describes a combiner system
with monitoring, mechanically constructed using conventional screw-down
terminal
blocks without quick-connectors. This invention inherits the installation
problems of
conventional systems.
11/379,728
US Patent Application 11/379,728 by McClintock et al discusses a combiner box
for use in the solar industry intended to aid with fault detection. It refers
to several
previous US Patents that are also concerned with fault detection. Although it
mentions improved installation time, it does so in the context of eliminating
the need
to separately wire monitoring consoles. Moreover, each combiner is designed to
connect to multiple strings in order to identify which is at fault.
12/468,984
US Patent Application 12/468,984 by Sok et al describes a solar array equipped
with combiner boxes including DC-DC power converters. The combiners are
themselves combined in parallel to form an array.
12/657,069
US Patent Application 12/657,069 by Fornage et all describes a connection
system for individual solar modules. These are combined in a generic load
center,
labeled 108 in the associated figures.
12/961,249
US Patent Application 12/961,249 by Brescia describes a systems for
integrating
modules into the building structure
Another small group of patents discusses custom combiner systems as part of a
custom panel or module installation system. These include:
12/796,466
US 7987641 (also known as CA 2702663) is concerned primarily with the
mechanical details of the new mounting system. In order to incorporate the
electrical
wiring, the patent proposes cutting channels into the frame of the panels, as
shown in
Figure 2A. This presents problems in terms of structural integrity
Application US 12/796,466 expands on US 7987641, induding a new wiring
system that addresses the problems of the earlier patent. This design moves
the
connectors from "free" wires on the back of the panel to a fixed location on
the side of
the panel frame. This way simply placing two panels next to each other allows
their
interconnection, and the electrical wiring is better protected.
Of interest, Figure 2A of US 12/796,466 illustrates an array build using the
patent's framing system. This includes a "combiner junction box" labeled 121".
This
combiner connects to the panels using MC4 connectors. The use of the same type
of
CA 02762078 2011-12-16
connector as found on the panel is a key part of the present invention. Figure
16
illustrates two strings being combined in an unlabeled combiner box, but the
application test does not mention this device nor does it appear to be part of
the
claims.
A larger number of patents discuss combiners, but do so as part of a standard
system. Some even refer to existing combiner systems using conventional
terminals.
12/714,855
US Patent Application 12/714,855 by Solon describes a system of wiring
harnesses that include in-line fuses for string protection. The patent shows
these being
used before connection to a conventional combiner.
12/288,956
US Patent Application 12/288,956 by Lewis and Herzog is likewise concerned
with fault detection and utilizes a monitor system that is wired into the
array in
advance of the combiners. It does not cover the combiners themselves.
12/582,367
US Patent Application 12/582,367 by Luebke et all describes a system of string
protection devices, some of which are placed inside combiner boxes. The patent
is
primarily concerned with the prevention of arc faults in addition to more
common
faults like shorts.
12/637,873
US Patent Application 12/637,873 by Hastings et al describes a system similar
to
12/582,367, using fault detection systems optionally included in the combiner.
The
patent appears very similar to 12/582,367, including several Figures in
common.
12/088,978
US Patent Application 12/088,978 by Thomspon et at describes a system of
srring-level monitoring systems known as StringPAK. These are connected
together
into groups of up to 10 panels using combiner boxes. The application does not
describe the combiner although it suggests the PCB10, which is a conventional
metal
NEMA3R combiner with conventional terminals.
12/562,933
US Patent Application 12/562,933 by Hadar et all describes a panel-level
monitoring system connected to a conventional combiner.
12/487,564
US Patent Application 12/487,564 by Gervorkian likewise describes a system
including panel-level monitoring that are built into arrays using conventional
combiners.
10/679,814
Like CA 2542672, 10/679,814 describes a custom solar panel that includes
electrical connectors as part of its structure. In this case the panels are
flat sheets that
CA 02762078 2011-12-16
connect together at the edges to form arrays. As in earlier examples, no
consideration
of string isolation is mentioned.
11/465,787
Another example of a custom panel/connector system is 11/465,787, which uses
cabling extended from the edge of a frameless panel that are connected
together using
splicing units. As in earlier examples, no consideration of string isolation
is mentioned.
Figure 12 and Figure 13 appear to show a combiner, but the associated text in
paragraph [0051] describes item 204 as an inverter.
11/777,397
US Patent Application 11/777,397 covers a roofing system with solar panels
built-
in, which are combined with a custom combiner into strings and arrays.
In spite of this extensive search, it appears that only a single patent even
attempts
to address the same problem, 10/612,873. However, Brown's invention retains
the
idea of a single larger combiner, lacking the modularity of the current
invention.
Additionally, it uses non-standard connectors throughout, which essentially
eliminates
its utility - which may be why there appears to have been zero adoption of
this
concept.
The rest of the patents discuss combiners and similar technologies only in
passing.
as part of other technologies. None of these appear to even consider the
wiring issues
the present invention addresses. Only one, 12/796,466, even shows an
electrical box
like those used in the industry, and does so only because their design demands
a
custom connection system due to non-standard connector use.
