U.S. patent application number 13/619203 was filed with the patent office on 2013-01-10 for photovoltaic ac inverter mount and interconnect.
This patent application is currently assigned to Enphase Energy, Inc.. Invention is credited to Rajan N. Kapur, Robert R. Rotzoll.
Application Number | 20130012061 13/619203 |
Document ID | / |
Family ID | 40026294 |
Filed Date | 2013-01-10 |
United States Patent
Application |
20130012061 |
Kind Code |
A1 |
Rotzoll; Robert R. ; et
al. |
January 10, 2013 |
PHOTOVOLTAIC AC INVERTER MOUNT AND INTERCONNECT
Abstract
A replaceable photovoltaic inverter is mounted on each of a
plurality of photovoltaic module for the conversion of direct
current, produced by the photovoltaic cells, to alternating
current. The inverter is coupled to a mounting bracket on the
photovoltaic module such that is can be easily replaced.
Replacement of an individual photovoltaic module inverter can occur
during continuous operation of the photovoltaic module system with
minimal impact on overall power production. The inverter is also
mounted apart from the photovoltaic module to facilitate heat
transfer generated by operation of the inverter.
Inventors: |
Rotzoll; Robert R.;
(Cascade, CO) ; Kapur; Rajan N.; (Boulder,
CO) |
Assignee: |
Enphase Energy, Inc.
Petaluma
CA
|
Family ID: |
40026294 |
Appl. No.: |
13/619203 |
Filed: |
September 14, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12121578 |
May 15, 2008 |
|
|
|
13619203 |
|
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|
|
60938663 |
May 17, 2007 |
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Current U.S.
Class: |
439/535 |
Current CPC
Class: |
H02J 3/383 20130101;
Y02E 60/00 20130101; Y02E 10/56 20130101; H02S 40/32 20141201; H02J
3/381 20130101; Y02E 60/7815 20130101; Y04S 40/121 20130101; H02J
2300/24 20200101; H02M 7/493 20130101; Y02B 90/20 20130101; H02M
7/003 20130101; Y02B 10/10 20130101 |
Class at
Publication: |
439/535 |
International
Class: |
H01R 13/60 20060101
H01R013/60 |
Claims
1. Apparatus for coupling power generated by a photovoltaic (PV)
module to an output, comprising a mounting bracket comprising: a
plurality of electrical receptacles for electrically coupling an
inverter to the mounting bracket without any external wiring; a
locking clip for locking the inverter to the mounting bracket; a DC
connection from a DC output of the PV module to a first subset of
electrical receptacles of the plurality of electrical receptacles
for providing DC power from the PV module to the inverter; and at
least one AC connector, coupled to a second subset of electrical
receptacles, for receiving AC power from the inverter.
2. The apparatus of claim 1, wherein the plurality of electrical
receptacles are recessed into the mounting bracket.
3. The apparatus of claim 1, wherein the mounting bracket retains
the inverter such that the inverter is physically spaced apart from
the PV module.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S.
non-provisional patent application Ser. No. 12/121,578 filed May
15, 2008, which further claims the benefit of U.S. provisional
patent application Ser. No. 60/938,663, filed May 17, 2007, both of
which are herein incorporated by reference in their entirety. The
present application is further related to co-pending U.S. patent
application Ser. No. 12/121,616 entitled, "Distributed Inverter and
Intelligent Gateway", and filed May 15, 2008, and U.S. patent
application Ser. No. 12/121,580 entitled "Photovoltaic
Module-Mounted AC Inverter" and filed May 15, 2008, both of which
are hereby incorporated by this reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to electrical current power conversion
and, more particularly, to a mount for an inverter configured to
convert photovoltaic module output power into alternating
current.
[0004] 2. Relevant Background
[0005] An inverter is a device that converts direct current ("DC")
into alternating current ("AC"). Inverters can be designed to
supply power from photovoltaic ("PV") modules to a utility power
grid, also referred to herein as the "grid." This process places
several special constraints on the power conversion process.
Existing photovoltaic inverters generally fall into the category of
centralized inverters wherein a single inverter performs power
conversion of the DC supplied by a group of PV modules into the
desired AC grid.
[0006] Another category of inverters is known as distributed
inverters. A distributed inverter uses multiple inverters to
generate the desired AC power from a number of PV modules. When the
inverter is mounted on the PV module, the assembly comprising the
PV module and inverter is termed an AC module. Previous attempts at
development and marketing of AC modules have met with little
success. One reason for this failure has been that the sales volume
was too low to achieve any kind of economies of scale.
Additionally, the components used in the distributed inverters
associated with AC modules were off-the-shelf and, in many cases,
were not optimized for the rigors of supplying AC power to the
grid. The reliability levels of existing off-the-shelf components
used in the inverters limits their lifetime to between five and ten
years. Additionally, there can be up to 1000 components in an
inverter resulting in significant cost per unit of energy.
Furthermore, the complexity and system requirements of such an
inverter result in a cumbersome package that is difficult to attach
to a PV module.
[0007] Referring now to FIG. 1, the back-side 110 of a PV module
102 including a PV module-mounted inverter 104 as known in the
prior art is shown. A junction box 103, normally a component of the
PV module 102, is permanently attached to the PV module 102 frame
via an adhesive. The junction box 103 encloses and protects the DC
connections from the module 102, including bypass diodes used to
shunt current around disabled or non-producing PV cells within the
module. The PV module 102 DC outputs typically leave the junction
box 103 via single-wire cables 112, 113 and connect to an inverter
104. The inverter 104 is mounted to the frame of PV module 102 near
an edge 111 of the PV module. The weight and size of the inverter
may vary, and in many instances further measures are needed to
improve support to the inverter 104 including mounting it at a
corner of the frame, adding metal brackets to the frame or even
mounting the inverter on the members that ultimately support the PV
module 102. Cables 106,107 from the inverter connect the PV module
102 to the AC grid and to other PV module-mounted inverters via
connectors 105, 108. The cables 106, 107 are connected together,
according to one system of implementation and as described in
related application Ser. No. ______ in parallel within the inverter
104 so that all voltages on the pins of the first connector 105
also appear on the corresponding pins of the second connector 108.
The cables 106, 107 and connectors 105, 108 are typically designed
to support single-phase, single pole or single-phase, two-pole AC
grid interconnection, and each requires a minimum of three
conductors. The connectors are defined to allow for chains of
inverters to be developed in which the AC grid connection is
accessible to all inverters by simply connecting the connector 108
of one inverter 104 to another connector 105 of an adjacent PV
module-mounted inverter in a system. The inverter 104 typically has
a metallic enclosure, requiring that an equipment grounding
conductor be brought through cables 106, 107 for electrical code
mandated safety ground.
[0008] Referring to FIG. 2, an array 201 of PV modules 202, 222,
242 including PV module-mounted inverters 204, 224, 244 as known in
the prior art is shown. In the configuration shown, connector 205
is connected to the grid. As referred to herein the grid will be
recognized by on skilled in the art of electrical generation and
local electric grid systems. This grid includes not only the
ability to use the power produced by the PV modules locally, for
example to power a commercial enterprise or residence, but also to
sell back excess or unused power to a community electric grid. The
AC grid voltage appears at connector the 208 and is passed to the
inverter 224 of the PV module 222 via another connector 225, which
is mated with a receiving connector 208. Similarly, the same AC
voltage is now available at a similar inverter 244 via the mating
of a like connector 228 to another receiving connector 245. This
sequence can continue until the maximum current rating of all
cables 206, 207, 226, 227, 246, 247 and 266 has been exhausted.
[0009] FIG. 3 is a side end view of a PV module 301 including a PV
module-mounted inverter 306 as is known in the prior art. The
height of the frame 304 of the module typically measures about one
inch. The junction box 305 and inverter 306 are generally attached
to the top side 302 of the module 301. The height of junction box
305 typically remains below the frame height and therefore does not
protrude below the lower edge of the frame 303. However, existing
inverter designs are considerably taller than the frame height 304
due to their complexity and protrude below the module frame. Since
PV modules are typically stacked frame-to-frame, a tall inverter
impedes pre-assembly of the inverter to the PV module prior to
shipment and severely impacts the ability to service a PV module or
inverter in the field should one fail after installation.
[0010] Additionally, existing designs of PV module-mounted
inverters present significant reliability problems. Inverters
occasionally fail. When such an event occurs the PV module to which
it is attached is no longer contributing in the production of
electricity for the system. The identification of that singular PV
module failure, however, is extremely difficult as there is no
outright indication that a PV module has failed. Generally the only
indication of a PV module failure is a decrease in power
production. This is compounded with the fact that each PV module
and its installation in a system represents a significant capital
outlay. A failure of an inverter, should it be identified, results
in the replacement of the entire PV module. To do such a repair,
under the systems and inverters currently used in the prior art,
the entire PV system must be taken off line. Not only is the
replacement of the entire PV system costly, but the loss in power
production of at least a significant portion of the entire PV
system while a single module is replaced is inefficient.
[0011] The weight, size, metallic enclosure and relatively low
efficiency of the existing inverter designs result in a more
complex mounting arrangement and a considerable increase in cost
over a centralized inverter approach. But a centralized inverter is
also not an optimal solution. Yet, the benefits of maximum
power-point tracking optimization normally achieved by having an
inverter at each PV module easily can be lost by a lack of power
efficiency. Also the lifetime of an inverter is less than that of a
PV module; therefore, any inverter mounted onto a PV module in a
distributed model will need replacement at some point during the
life of the PV module. Finally, existing inverters are difficult to
replace due to their weight, anchoring schemes and wiring.
[0012] An efficient inverter that creates little heat, is
lightweight in construction, is easily replaced and minimizes
exposed wiring remains a challenge. Compounding this challenge is
that such an invention should also minimize system cost and easily
fit within the depth of the PV module frame. These and other
deficiencies of the prior art are addressed by embodiments of the
present invention
SUMMARY OF THE INVENTION
[0013] According to one embodiment of the present invention, a
replaceable PV module-mounted AC inverter is designed to be
inserted into an inverter mounting bracket. The inverter mounting
bracket is attached to the back of a PV module via adhesive of some
other means. The inverter and inverter mounting bracket are made of
non-conducting materials to remove electrical code requirements for
equipment grounding conductors. The inverter is coupled to the
bracket via locking mounting clips on the inverter mounting bracket
that lock into inverter mounting recesses. No tools are required to
insert the inverter into the bracket and only a simple blade
screwdriver is required to release the clips for removal and
replacement of the inverter.
[0014] According to one embodiment of the present invention, the
inverter is spaced from the back surface of the PV module to
minimize heating of the PV module by the inverter and to provide
for convective air flow surrounding the inverter to dissipate heat
generation. Furthermore, the inverter can be replaced while the PV
module and indeed the entire PV module system remains operational.
According to one embodiment of the present invention, by virtue of
the joining mechanism of the inverter to the PV module bracket, an
inverter can safely be removed from the bracket/interconnect with
minimal fear of an arc and without disrupting the production of
power from the remaining PV modules.
[0015] There are, according to one embodiment, two inverter
mounting bracket AC connections to support daisy-chain connections
between multiple AC modules. The AC connections can be made using
bracket mounted connectors or by using cables affixed to the
bracket. Finally, AC connections can be a combination of one
affixed cable and one bracket-mounted connector.
[0016] The inverter mounting bracket DC connections, according to
one embodiment of the present invention, can be implemented inside
the bracket by mounting the bracket on top of the DC connections of
a PV module. Additional external single-wire cables can be added to
accommodate connection to an existing junction box mounted on a PV
module.
[0017] For applications requiring permanent inverter installation
without the capability of field replacement of the inverter, the
inverter can be completely enclosed by the bracket to result in a
very reliable and low-cost bracket implementation. By removing the
interface between the bracket and the inverter, the reliability of
the PV module is enhanced at the cost of the flexibility to replace
an inverter in the field.
[0018] The features and advantages described in this disclosure and
in the following detailed description are not all-inclusive. Many
additional features and advantages will be apparent to one of
ordinary skill in the relevant art in view of the drawings,
specification, and claims hereof Moreover, it should be noted that
the language used in the specification has been principally
selected for readability and instructional purposes and may not
have been selected to delineate or circumscribe the inventive
subject matter; reference to the claims is necessary to determine
such inventive subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The aforementioned and other features and objects of the
present invention and the manner of attaining them will become more
apparent, and the invention itself will be best understood, by
reference to the following description of a preferred embodiment
taken in conjunction with the accompanying drawings, wherein:
[0020] FIG. 1 is a layout diagram of the back-side of an AC module
as is known in the prior art;
[0021] FIG. 2 is a layout diagram of the back side of an AC PV
module system as is known in the prior art;
[0022] FIG. 3 is a side end view schematic of an AC module as is
known in the prior art;
[0023] FIG. 4 is a mechanical drawing of an inverter according to
one embodiment of the present invention;
[0024] FIG. 5 is a mechanical drawing of an inverter mounting
bracket according to one embodiment of the present invention;
[0025] FIG. 6 is a mechanical drawing of an inverter inserted into
an inverter mounting bracket according to one embodiment of the
present invention;
[0026] FIG. 7 is a mechanical drawing of a an inverter mounting
bracket according to one embodiment of the present invention;
[0027] FIG. 8 is a mechanical drawing of a an inverter mounting
bracket according to one embodiment of the present invention;
[0028] FIG. 9 is a layout drawing of the placement of inverters,
inverter mounting brackets, associated AC cables and PV modules
according to one embodiment of the present invention;
[0029] FIG. 10 is layout drawing of the placement of inverters,
inverter mounting brackets, associated AC cables and PV panels
according to one embodiment of the present invention;
[0030] FIG. 11 is a mechanical drawing of a an inverter mounting
bracket according to another embodiment of the present
invention;
[0031] FIG. 12 is a layout drawing of the placement of an inverter
mounting bracket, inverter and associated AC and DC cables on the
back of a PV module with a junction box according to one embodiment
of the present invention;
[0032] FIG. 13 is a mechanical drawing of an inverter mounting
bracket with an enclosed inverter according to one embodiment of
the present invention;
[0033] FIG. 14 is a mechanical drawing of an inverter mounting
bracket with a recessed pin to enable power-on replacement of the
inverter, according to one embodiment of the present invention;
and
[0034] FIG. 15 is a flowchart showing one method embodiment for
removing a PV inverter from a fully operational PV module.
[0035] The Figures depict embodiments of the present invention for
purposes of illustration only. One skilled in the art will readily
recognize from the following discussion that alternative
embodiments of the structures and methods illustrated herein may be
employed without departing from the principles of the invention
described herein.
DETAILED DESCRIPTION
[0036] Specific embodiments of the present invention are hereafter
described in detail with reference to the accompanying Figures.
Like elements in the various Figures are identified by like
reference numerals for consistency. Although the invention has been
described and illustrated with a certain degree of particularity,
it is understood that the present disclosure has been made only by
way of example and that numerous changes in the combination and
arrangement of parts can be resorted to by those skilled in the art
without departing from the spirit and scope of the invention.
[0037] Referring now to FIG. 4, a mechanical drawing including a
side 402 and top view 422 of a removable PV module-mounted power
element according to a one embodiment of the present invention is
shown. According to one embodiment of the present invention the
power element 422 can be an inverter capable of converting DC power
to AC power. In another embodiment of the present invention the
power module is a DC conditioner capable of modifying the DC
characteristics including, but not limited to voltage. While the
present invention is hereafter described in terms of an inverter,
one skilled in the art will recognize that the power element 422
can possess multiple functionalities without departing from the
spirit of the invention.
[0038] Referring again to FIG. 4, a potted assembly inverter 422 in
a non-conductive enclosure is shown with metallic blade connectors
404, 405, 406, 407, 408, 409, 410 to bring AC and DC wiring
connections out of the enclosure 402. The blade connectors 404,
405, 406, 407, 408, 409, 410 are designed to support high voltage
and high current operation consistent with a single PV module
output power. Recessed mounting holes 403, 420, 421 are used in
conjunction with a mounting clip to secure the inverter in the
mounting bracket using a single installation motion. The dimensions
and aspect ratio of the inverter 422 may be adjusted to support
differing power requirements based on PV module design. The
inverter is lightweight--generally less than 16 ounces--and does
not significantly load the PV module to which it is attached.
[0039] FIG. 5 shows, according to another embodiment of the present
invention, a mechanical drawing of a side 505 and top view 510 of
an inverter mounting bracket mounted on the back of a PV module
502. The bracket is attached to the back of a PV module 502 by an
adhesive 509 that is placed between bracket 505 and PV module 502
prior to assembly. The bracket 505 is molded from a non-conductive
material, such as a composite plastic or the like, to minimize
cost. Mounting clips 503, 511, 512 are used to lock the inverter in
place once the inverter is inserted into the electrical
high-voltage receptacles 520, 521, 522, 523, 524, 525 of the
bracket 505. DC wiring connections 507 from the inverter
receptacles to the PV module are made by wire or bus-bar means.
Connectors 504, 530, 531 are used to make all AC connections to the
inverter via wires 506 to the inverter receptacles. The connectors
504 can be discrete or can be molded into the body of bracket 505.
Inverter receptacles 520, 521, 522, 523, 524, 525 may be recessed
into the bracket to improve protection against weather, sunlight,
ultraviolet radiation and other environmental features.
[0040] FIG. 6 shows a side and top view of an inverter 602 inserted
into an inverter mounting bracket 604 according to an embodiment of
the present invention. The high voltage pins 620, 621, 622, 623,
624, 625 of the inverter are inserted into the bracket 604
receptacles. The inverter is locked into place to eliminate
disengagement via vibration or accidental means via locking clips
612, 615 that engage inverter mounting holes 613, 614. The design
of the inverter 602 and inverter mounting bracket 604 results in
spacing 603 of the inverter 602 from the back surface of PV module
605 thereby reducing heating of PV module 605 by heat generated in
the inverter 602. It is well known that the conversion of DC power
to AC power by an inverter produces as a by product, heat. In a
centralized type of system configuration in which DC power
transported away from the PV modules for conversion, heat
production by the inverter is of little concern. However in system
in which an inverter is coupled to each PV module the generation of
heat can significantly reduce the efficiency of each photovoltaic
cell. To better understand the implications of heat generated by an
inverter consider how a PV module operates.
[0041] PV modules operate as current sources derived from a
photoexcited semiconductor junction. The maximum available power
from the PV cell is defined by the product of its output voltage
and current. The current is due to generated photocarriers and, at
low output voltages, will be proportional to the incident
illumination on the PV cell and is termed the photocurrent. The PV
cell behaves as if it has a photocurrent source in parallel with a
non-illuminated junction diode. The output voltage is defined by
the diode circuit effects implicit in the semiconductor junction
and ultimately limits the maximum useful output voltage to a point
where the diode current begins to increase significantly. Diode
current is a strong function of operating temperature and results
in a reduced PV cell voltage for a given output current as
temperature rises. PV module output power therefore decreases with
temperature. This effect requires that the PV module temperature be
kept as low as possible by mitigating any related heat sources as
much as possible.
[0042] Previous designs neglect to consider this important aspect
of power production. According to one embodiment of the present
invention, a replaceable inverter 602 is mounted physically apart
from the PV module. By maximizing surface area of the inverter open
to surrounding air currents the heat produced by each inverter can
be dissipated away from the inverter by way of convection to the
atmosphere and not to the PV module.
[0043] No tools are required to insert the inverter and only a
simple blade screwdriver is required to release the clips for
removal and replacement.
[0044] Shown in FIG. 7 is a mechanical drawing, according to
another embodiment of the present invention, of a side 703 and top
view 710 of an inverter mounting bracket capable of being mounted
on the back of a PV module 702. The bracket is identical in design
to the embodiment shown in FIG. 5 with the exception of the method
of AC connections. AC connections shown in FIG. 7 are made using
multi-conductor cables 704, 730, 731 that are affixed to mounting
bracket 710. The cables 704, 730, 731 are directly connected via
internal wires 706 to bracket inverter receptacles 720, 721, 722,
723, 724, 725.
[0045] FIG. 8 shows another embodiment of an inverter mounting
bracket that can be mounted on the back of a PV module 802. The
first AC connection shown in FIG. 8 is made using multi-conductor
cable, 804 or 831, that is affixed to the mounting bracket 810. A
cable 831 is directly connected via internal wires 806 to bracket
inverter receptacles 820, 821, 822, 823, 824, 825. The second AC
connection is made via the bracket 810 mounted connector 830 and is
connected to the inverter receptacles 820, 821, 822, 823, 824, 825
via additional wiring 806. The connector 830 may be discrete or
molded into the body of bracket 810.
[0046] FIG. 9 is a layout drawing, according to one embodiment of
the present invention, showing the backside of an array 901 of PV
modules 902, 912, 922 with inverter mounting brackets 904, 914, 924
attached at the DC connection location of each module. Inverters
903, 913, 923 are inserted into inverter mounting brackets 904,
914, 924, respectively. Multi-wire AC connecting cables 915, 925
are shown connecting the inverters. A multi-wire AC connecting
cable 905 is shown connecting the inverters on the PV modules in
the drawing and the AC grid (not shown).
[0047] FIG. 10 is also a layout drawing, according to another
embodiment of the present invention, showing the backside of an
array 1001 of PV modules 1002, 1012, 1022 with inverter mounting
brackets 1004, 1014, 1024 attached at the DC connection location on
PV modules 1002, 1012, 1022. The inverters 1003, 1013, 1023,
according to the embodiment shown in FIG. 7, are inserted into
inverter mounting brackets 1004, 1014, 1024, respectively.
Multi-wire AC connecting cables 1006, 1015 are connected together
via connectors at the end of each bracket affixed cable. Additional
multi-wire AC connecting cables 1016, 1025, 1026, 1035 are
connected together via connectors at the end of each bracket
affixed cable. The assembly is thereafter connected to the AC
grid.
[0048] FIG. 11 shows a mechanical drawing of a top view of an
inverter mounting bracket 1110 capable of being mounted on the back
of a PV module. Bracket 1110 is similar in design to the embodiment
shown in FIG. 7 with the exception of the design of the DC
connections. In this embodiment, the DC connections are made using
single-wire cables 1111, 1112 that are affixed to mounting bracket
1110. Cables 1111, 1112 are directly connected via their internal
wires to bracket inverter receptacles 1120, 1121, 1122, 1123, 1124,
1125. The DC cables 1111, 1112 may be placed in other locations
than those shown in FIG. 11.
[0049] Likewise, FIG. 12 presents a layout drawing showing the
backside 1214 of a PV module 1212 with inverter mounting bracket
1203 attached according to one embodiment of the present invention.
An inverter 1202 is shown inserted into the top of inverter
mounting bracket 1203. AC cables 1210, 1211 are shown leaving the
bottom of bracket 1203. Single-wire DC cables 1206, 1207 connect
the junction box 1205 to the inverter mounting bracket 1203. This
allows the inverter to be used with existing manufactured PV
modules 1212 that have junction boxes 1205 pre-assembled without
any modifications to PV modules 1212.
[0050] According to another embodiment of the present invention and
as shown in FIG. 13, a bracket 1302 is attached to the back of PV
module 1303 by an adhesive 1308 that is placed between bracket 1302
and PV module 1303. The bracket 1302 is molded from a
non-conductive material, such as a composite plastic or the like,
to minimize cost. The inverter 1304 is completely enclosed within
bracket 1302. Inverter connections 1320, 1321, 1322, 1323, 1324,
1325 are connected to AC connectors 1306, 1330, 1331 and the PV
module by internal wiring. Cables 730, 731 of the inverter mounting
bracket 710 shown in FIG. 7 may be substituted for the connectors
1306, 1330, 1331 shown in FIG. 13. Likewise, the cable of the
inverter mounting bracket 810 shown in FIG. 8 may be substituted
for the connector 1331 shown in FIG. 13.
[0051] FIG. 14 is a mechanical drawing according to another
embodiment of the present invention showing a top view of an
inverter mounting bracket 1410 mounted on the back of a PV module.
The bracket 1410 is identical in design to the embodiment of FIG. 5
with the exception of the method of placement of the inverter
connection receptacles. An inverter connection receptacle 1425 is
shown partially recessed into the bracket. When the inverter is
removed from the bracket 1410, the associated connector pin on the
inverter is disconnected from receptacle 1410 prior to the inverter
pins connected to receptacles 1420, 1421, 1422, 1423, 1424 being
disengaged. A detection circuit is implemented in the inverter to
determine that the connection to the receptacle 1410 has been
broken and thereby disables all power currents into and out of the
inverter. As a result, no arc is formed at the receptacles 1420,
1421, 1422, 1423, 1424 when the inverter is removed. Similarly,
power current flow into and out of the inverter is not enabled
until after a complete connection has been made on the receptacle
1425 after the power connections have been established on receiving
receptacles 1420, 1421, 1422, 1423, 1424. Since the connections
have been established prior to the enabling of current, no arc can
occur at the connection 1420, 1421, 1422, 1423, 1424. The recessed
receptacle 1410 and associated detection circuitry implements a
hot-swap function in which the inverter can be removed and replaced
while voltages remain active on all the AC and DC connections to
the inverter without creating a potentially hazardous arc.
[0052] Similarly the connector pin 425 upon replacement of the
inverter prevents operations of the inverter prior to the
connection of the receptacles 1420, 1421, 1422, 1423, 1424. As the
inverter is mated with the inverter bracket, each receptacle of the
inverter mates with a corresponding connection of the inverter
bracket. Subsequent to the connections being made the connection
pin 1425 establishes contact with a corresponding component of the
inverter bracket signifying that operation of the inverter can
safely begin. In one embodiment the connection pin is a recessed
pin/receptacle combination over which a simple continuity circuit
can be attached while in another the pin is a telescoping pin
coupled to a switch that signifies whether a complete connection or
extraction of the inverter.
[0053] FIG. 15 is a flowchart illustrating methods of implementing
an exemplary process for replacing a PV inverter associated with a
PV module. In the following description, it will be understood that
some blocks of the flowchart illustration, and combinations of
blocks in the flowchart illustrations, can be implemented by
computer program instructions while other blocks represent physical
methodology. When implemented by a computer, these computer program
instructions may be loaded onto a computer or other programmable
apparatus to produce a machine such that the instructions that
execute on the computer or other programmable apparatus create
means for implementing the functions specified in the flowchart
block or blocks. These computer program instructions may also be
stored in a computer-readable memory that can direct a computer or
other programmable apparatus to function in a particular manner
such that the instructions stored in the computer-readable memory
produce an article of manufacture including instruction means that
implement the function specified in the flowchart block or blocks.
The computer program instructions may also be loaded onto a
computer or other programmable apparatus to cause a series of
operational steps to be performed in the computer or on the other
programmable apparatus to produce a computer implemented process
such that the instructions that execute on the computer or other
programmable apparatus provide steps for implementing the functions
specified in the flowchart block or blocks.
[0054] Accordingly, blocks of the flowchart illustrations support
combinations of means for performing the specified functions and
combinations of steps for performing the specified functions. It
will also be understood that each block of the flowchart
illustrations, and combinations of blocks in the flowchart
illustrations, can be implemented by various means including a
computer, robotics, or via human implementation. Indeed many of the
steps illustrated in FIG. 15 can comprise multiple steps that are
not listed herein as they would be well known to one skilled in the
art. Furthermore the steps listed and discussed below are one
example of a process for replacing a PV inverter associated with a
PV module according to the present invention.
[0055] FIG. 15 begins 1505 with the identification 1510 of a PV
inverter in need of replacement. The identification of an inverter
can be due to failure of the inverter, periodic or preventive
maintenance or for other reasons known to one skilled in the art.
The determination of what PV inverter in a PV system needs to be
replaced is not trivial and is not the subject of this invention.
Upon identification 1510 the PV inverter is released 1520 from its
mounting bracket. Upon release of any physical restraints holding
the PV to the inverter bracket the PV inverter can be extracted
1530 from the bracket. Note that during this process, and according
to one embodiment of the present invention, the PV system remains
operational and indeed the PV module to which the PV inverter is
associated continues to provide DC power to the PV inverter.
[0056] As the PV inverter is removed from the inverter bracket but
prior to the connectors mating the PV module to the PV inverter
from breaking contact, a connector pin indicates 1540 to the
inverter that a secure connection between the inverter bracket and
the PV inverter has been compromised. Responsive to the connector
pin breaking contact, the PV inverter ceases operation 1550. As one
skilled in art will recognize the termination of operation of the
PV inverter can be accomplished by a number of methodologies.
According to one embodiment a detection circuit is included in the
PV inverter to ensure that a positive connection exists between the
PV module (inverter bracket) and the PV inverter prior to
converting the DC power to AC power. The process ends 1595 with the
inverter being safely removed 1560 from an operation PV module
without any electrical arc or danger to the technician.
[0057] While there have been described above the principles of the
present invention in conjunction with a PV module AC inverter mount
and interconnect, it is to be clearly understood that the foregoing
description is made only by way of example and not as a limitation
to the scope of the invention. Particularly, it is recognized that
the teachings of the foregoing disclosure will suggest other
modifications to those persons skilled in the relevant art. Such
modifications may involve other features that are already known per
se and which may be used instead of or in addition to features
already described herein. Although claims have been formulated in
this application to particular combinations of features, it should
be understood that the scope of the disclosure herein also includes
any novel feature or any novel combination of features disclosed
either explicitly or implicitly or any generalization or
modification thereof which would be apparent to persons skilled in
the relevant art, whether or not such relates to the same invention
as presently claimed in any claim and whether or not it mitigates
any or all of the same technical problems as confronted by the
present invention. The Applicant hereby reserves the right to
formulate new claims to such features and/or combinations of such
features during the prosecution of the present application or of
any further application derived therefrom.
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