Title of Invention

POWER DELIVERY SYSTEM INCLUDING INTERCHANGEABLE CELLS

Abstract A power cell system includes a structure that provides multiple power cell locations. The system also includes at least one regenerative power cell, and at least one non-regenerative power cell. The cell locations and power cells are sized and position so that each cell location may interchangeably accept either a regenerative power cell or a non-regenerative power cell.
Full Text POWER DELIVERY SYSTEM INCLUDING INTERCHANGEABLE CELLS
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims priority to, and incorporates by reference in its
entirety, the following applications: (i) pending U.S. Provisional Patent Application No.
60/713,198, entitled "A system and method for a configurable power infrastructure including
interchangeable cells," filed August 31, 2005; and (ii) pending U.S. Provisional Patent
Application No. 60/713,197, entitled "Packaging method for modular multilevel power cells and
system infrastructure," filed August 31, 2005.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not applicable.
NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT
[0003] Not applicable.
INCORPORATION BY REFERENCE OF MATERIAL ON DISK
[0004] Not applicable.
BACKGROUND
[0005] In recent years, circuits for medium-voltage variable frequency drive (VFD)
applications have received attention. Several novel methods have been introduced in the past
decade. For example, in a circuit comprising series-connected inverters as described in U.S.
Patent No. 5,625,545 to Hammond, the disclosure of which is incoiporated herein by reference in
its entirety, an inverter or power cell 110 includes a three-phase diode-bridge rectifier 112, one
or more direct current (DC) capacitors 114, and an H-bridge inverter 116. The rectifier 112
converts the input 118 alternating current (AC) voltage to a substantially constant DC voltage
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that is supported by the capacitors 114 that are connected across the rectifier 112 output. The
output stage of the inverter 110 includes an H-bridge inverter 116 that includes two poles, a left
pole and a right pole, each with two devices. The inverter 110 transforms the DC voltage across
the DC capacitors 114 to an AC output 120 using pulse-width modulation (PWM) of the
semiconductor devices in the H-bridge inverter 116.
[0006] A circuit including power cells such as 110 in FIG. 1, when connected to a
load, such as a motor, can provide power from an input source to the motor when operating in
the motoring mode. Such a power cell may sometimes be referred to as a unidirectional or two-
quadrant (2Q) cell. This is because when the four quadrants of speed and torque are considered,
referring to FIG. 2, the operating characteristics 210 of this cell are such that it operates in either
the quadrant where both speed and torque are positive (first quadrant 201) or the quadrant where
both speed and torque are negative (third quadrant 203).
[0007] However, when the motor speed needs to be reduced, power from the motor
needs to be absorbed by the inverter. This mode of operation, when power must be absorbed by
the inverter, is referred to as the regeneration mode. In such situations, regenerative or four-
quadrant cells are required. An example of a regenerative cell is shown in U.S. Patent No.
6,301,130 to Hammond. As shown in FIG. 3, a regenerative power cell 360 may include an
active front end 362 that serves as a first converter that uses insulated gate bipolar transistors
(IGBTs) Q5 - Q10 or other switching devices controlled by PWM. The first converter 362 is
electrically connected in parallel to a second converter 364 and to one or more DC link
capacitors 366. Such a cell receives power from a transformer 346 and delivers it to other cells
in the group and a load 349. Referring to FIG. 2, this cell permits operating characteristics 220
in all four quadrants 201 - 204, including the quadrant where both speed and torque are positive
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(first quadrant 201), the quadrant where torque is positive and speed is negative (second quadrant
202), the quadrant where both speed and torque are negative (third quadrant 203), and the
quadrant where torque is negative and speed is positive (fourth quadrant 204).
[0008] In the prior art, motor systems included two-quadrant or four-quadrant cells.
However, systems that are designed to accommodate one or the other are limited in applicability.
The disclosure contained herein describes attempts to solve one or more of the problems
described above.
SUMMARY
[0009] In an embodiment, a power cell system includes a support structure having a
plurality of cell locations, at least one regenerative power cell, and at least one non-regenerative
power cell. The cell locations and power cells are sized and positioned so that each cell location
may interchangeably accept either a regenerative power cell or a non-regenerative power cell.
Optionally, each cell location may include support rails, a power delivery bus positioned to
electrically connect with an input bus of a power cell that is in the cell location, and a power
output bus positioned to electrically connect with an input bus of the power cell that is in the cell
location. In addition, each power cell may include a chassis, such that each chassis in the system
has substantially the same size and shape as the other chassis in the system. The system also
may include a wire tray that holds control wire for each power cell.
[0010] In an alternate embodiment, a power cell system includes a plurality of support
rails and a back plane that are connected to provide a plurality of cell locations. The system also
includes at least one regenerative power cell, and at least one non-regenerative power cell. The
cell locations and power cells are sized and positioned so that each cell location may
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interchangeably accept either a regenerative power cell or a non-regenerative power cell. Each
power cell includes a chassis, and each chassis in the system has substantially the same size and
shape as the chassis for a at least some of the other power cells in the system. Optionally, each
cell location may include a plurality of support rails, a power delivery bus positioned to
electrically connect with an input bus of a power cell that is in the cell location, and a power
output bus positioned to electrically connect with an input bus of the power cell that is in the cell
location. The system also may include a wire tray that holds control wire for each power cell.
[0011] In an alternate embodiment, a power delivery system includes a support
structure comprising a plurality of cell locations, at least one regenerative power cell, and at least
one non-regenerative power cell. The cell locations and power cells may be sized and positioned
so that each cell location may interchangeably accept either a regenerative power cell or a non-
regenerative power cell. Each power cell may include a chassis, and each chassis in the system
may have substantially the same size and shape as the chassis for a at least some of the other
power cells in the system. Each cell location may include a plurality of support rails, a power
delivery bus positioned to electrically connect with an input bus of a power cell that is in the cell
location, and a power output bus positioned to electrically connect with an input bus of the
power cell that is in the cell location.
[0012] In each of the embodiments described above, each regenerative power cell may
optionally include an inverter bridge, a capacitor set electrically connected across terminals of
the inverter bridge, and an active front end that includes a plurality of transistors electrically
connected as a three-phase bridge. Alternatively, each regenerative power cell may include an
inverter bridge, a capacitor set electrically connected across terminals of the inverter bridge, a
three-phase diode bridge rectifier electrically connected across the terminals, and a series-
4

connected transistor and resistor combination that is electrically connected across the terminals.
Also optionally, each non-regenerative power cell may include an inverter bridge, a capacitor set
electrically connected across terminals of the inverter bridge, and a three-phase bridge rectifier
electrically connected across the terminals. Other configurations of regenerative and non-
regenerative cells are possible.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a circuit diagram showing exemplary characteristics of a prior art
non-regenerative power cell.
[0014] FIG. 2 depicts operating in four quadrants of speed and torque.
[0015] FIG. 3 is a circuit diagram showing exemplary characteristics of a prior art
regenerative power cell.
[0016] FIG. 4 depicts a circuit comprising a plurality of power cells connected to a
load.
[0017] FIG. 5 illustrates an exemplary power cell housing structure.
[0018] FIG. 6 illustrates an exemplary support structure for multiple power cells.
[0019] FIG. 7 illustrates the support structure of FIG. 6 with a cell positioned in a cell
location.
DETAILED DESCRIPTION
[0020] Before the present methods, systems and materials are described, it is to be
understood that this disclosure is not limited to the particular methodologies, systems and
materials described, as these may vary. It is also to be understood that the terminology used in
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the description is for the purpose of describing the particular versions or embodiments only, and
is not intended to limit the scope. For example, as used herein and in the appended claims, the
singular forms "a," "an," and "the" include plural references unless the context clearly dictates
otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same
meanings as commonly understood by one of ordinary skill in the art. In addition, the following
terms are intended to have the following definitions herein:
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[0021] comprising - including but not limited to.
[0022] electrically connected or electrically coupled - connected in a manner adapted
to transfer electrical energy.
[0023] H-bridge inverter - a circuit for controlled power flow between AC and DC
circuits having four transistors and four diodes. Referring to FIG. 1, an H-bridge inverter 116
generally includes a first phase leg and a second phase leg electrically connected in parallel.
Each leg includes two transistor/diode combinations. In each combination, the diode is
electrically coupled across the base and emitter of the transistor.
[0024] inverter - a device that converts DC power to AC power or AC power to DC
power.
[0025] medium voltage - a rated voltage greater than 690 volts (V) and less than 69
kilovolts (kV). In some embodiments, medium voltage may be a voltage between about 1000 V
and about 69 kV.
[0026] non-regenerative power cell - a power cell that does not have the capability of
absorbing regenerative power.
[0027] power cell - an electrical device that has a three-phase alternating current input
and a single-phase alternating current output.
[0028] rank - an arrangement of power cells established across each phase of a three-
phase power delivery system.
[0029] regenerative power cell - a power cell that has the capability of absorbing
regenerative power.
[0030] substantially - to a great extent or degree.
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[0031] In various embodiments, a multi-level power circuit includes a plurality of
power cells to drive a load. FIG. 4 illustrates an exemplary embodiment of a circuit having such
power cells. In FIG. 4, a transformer 410 delivers three-phase, medium-voltage power to a load
430 such as a three-phase induction motor via an array of single-phase inverters (also referred to
as power cells). The transformer 410 includes primary windings 412 that excite a number of
secondary windings 414 - 425. Although primary winding 412 is illustrated as having a star
configuration, a mesh configuration is also possible. Further, although secondary windings 414
- 425 are illustrated as having a mesh configuration, star-configured secondary windings are
possible, or a combination of star and mesh windings may be used. Further, the number of
secondary windings illustrated in FIG. 4 is merely exemplary, and other numbers of secondary
windings are possible. The circuit may be used for medium voltage applications or, in some
embodiments, other applications.
[0032] Any number of ranks of power cells are connected between the transformer 410
and the load 430. A "rank" is considered to be a three-phase set, or a group of power cells
established across each of the three phases of the power delivery system. Referring to FIG. 4,
rank 450 includes power cells 451-453, rank 460 includes power cells 461-463, rank 470
includes power cells 471-273, and rank 480 includes power cells 4S1-483. Fewer than four
ranks, or more than four ranks, are possible. A central control system 495 sends command
signals to local controls in each cell over fiber optics or another wired or wireless
communications medium 490.
[0033] FIG. 5 illustrates an exemplary power cell structure 510. The power cell 510
includes a chassis 512 and a set of power input/output connectors 521-525. Exemplary internal
components of the cell may include any number of capacitors, a heat sink, and an electronics
8

assembly that may include items such as insulated gate bipolar transistor (IGBT) modules and
one or more rectifier modules. The IGBTs may be separated for I/O bus locations and to
increase thermal performance.
[0034] The chassis 512 encloses various components of the power cell 510, such as
one or more capacitors, printed circuit boards, heat sinks, etc. The chassis 512 may be fabricated
from any suitable material, such as galvanized steel or another metal, that both mechanically and
electromagnetically isolates the power cell from other power cells in the system during both
normal operation and many abnormal operating conditions. The chassis 512 may serve to
protect internal components of the power cell 510 from damage during shipping and handling,
and it may be configured in a manner such that the electronic module 510 can be placed on any
of its sides without causing any damage to the components of the electronic module 510.
According to various embodiments, the chassis 512 may be comprised of several portions
connected together, and one or more portions of the chassis 512 may be removable. In addition,
the chassis 512 may be of a thickness sufficient to prevent any debris resulting from a failure of
the internal components of the electronic module 510 from exiting the space enclosed by the
chassis 512, thereby preventing any collateral damage to other components in the vicinity of the
electronic module 510.
[0035] As shown in FIG. 5, the power cell 510 may further comprise a plurality of
power plug connectors 521 - 525 coupled to an internal input or output power bus that is
configured to route power to and from the electronic module 510. For example, three of the
power plug connectors 522- 524 may be configured to receive three-phase power from a source,
while two of the power plug connectors 521 and 525 may be configured to deliver single-phase
9

power to a load.. The power plug connectors permit the cells to be plugged into a master power
plane.
[0036] The power cell arrangement described in FIGs. 4 and 5 provides a modular,
multilevel system that allows cells to be replaced as needed to accommodate different design
requirements, or to replace a failed cell. In addition, the cells 510 shown in FIG. 5 are physically
interchangeable so that they may contain either the elements of a two-quadrant cell, such as the
elements shown in FIG. 1, or the elements of a regenerative (four-quadrant) cell, such as the
elements shown in FIG. 3. In this manner, individual cell locations can be populated replaced as
with regenerative or non-regenerative cell as necessary to provide for a desired degree of
braking. The chassis 512 of each cell 510 will thus have substantially the same size and shape,
regardless or whether it is a regenerative cell or non-regenerative cell.
[0037] FIG. 6 illustrates an exemplary support structure 644 for multiple power cells,
such as nine cells, within a housing wherein each power cell or other electronic module is
positioned on one or more mounting rails 646 so that the rear of each cell faces a backplane 648
and the cell's power plugs contact the cell power connections 621-625 through the backplane
648. The backplane 648 may be fabricated from any suitable non-conductive material, such as a
high-strength non-conductive laminate material, and it provides a barrier between individual
cells and other aspects of the system.
[003 8] The support structure is designed to provide a plurality of cell locations 650,
each of which may receive an interchangeable cell (such as 510 in FIG. 5) that is either a
regenerative cell or a non-regenerative cell. In this manner, a single power cell system may
include all regenerative cells, all non-regenerative cells, or some mixture of regenerative and
non-regenerative cells depending on the desired degree of braking. A cell 510 may be sized to
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slide into a cell location 650 along the support rails 646, and the cell's power plugs will then
engage the cell power connections 621-625. Optionally, additional connections such as wire
trays 630 may be provided to accommodate control wires that are routed to and from the cells.
Also optionally, one or more secondary power busses 628 may be provided for the direction of
current to or from each cell. FIG. 7 illustrates the exemplary support structure 644 with a power
cell 510 positioned in one of the cell locations.
[0039] Still other embodiments will become readily apparent to those skilled in this art
from reading the above-recited detailed description and drawings of certain exemplary
embodiments. It should be understood that numerous variations, modifications, and additional
embodiments are possible, and accordingly, all such variations, modifications, and embodiments
are to be regarded as being within the spirit and scope of this application
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CLAIMS
What is claimed is:
1. A power cell system, comprising:
a support structure comprising a plurality of cell locations;
at least one regenerative power cell; and
at least one non-regenerative power cell;
wherein the cell locations and power cells are sized and positioned so that each cell
location may interchangeably accept either a regenerative power cell or a non-regenerative power
cell.
2. The system of claim 1, wherein each cell location comprises:
a plurality of support rails;
a power delivery bus positioned to electrically connect with an input bus of a power cell
that is in the cell location; and
a power output bus positioned to electrically connect with an input bus of the power cell
that is in the cell location.
3. The system of claim 1, each regenerative power cell comprises:
an inverter bridge;
a capacitor set electrically connected across terminals of the inverter bridge; and
an active front end comprising a plurality of transistors electrically connected as a three-
phase bridge.
4. The circuit of claim 1, wherein each regenerative power cell comprises:
an inverter bridge;
a capacitor set electrically connected across terminals of the inverter bridge;
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a three-phase diode bridge rectifier electrically connected across the terminals; and
a series-connected transistor and resistor combination that is electrically connected across
the terminals.
5. The system of claim 1, wherein each non-regenerative power cell comprises:
an inverter bridge;
a capacitor set electrically connected across terminals of the inverter bridge; and
a three-phase bridge rectifier electrically connected across the terminals.
6. The system of claim 1, wherein each power cell comprises a chassis, and each chassis in
the system has substantially the same size and shape as the other chassis in the system.
7. The system of claim 1, further comprising a wire tray that holds control wire for each
power cell.
8. A power cell system, comprising:
a plurality of support rails and a back plane that are connected to provide a plurality of
cell locations;
at least one regenerative power cell; and
at least one non-regenerative power cell;
wherein the cell locations and power cells are sized and positioned so that each cell
location may interchangeably accept either a regenerative power cell or a non-regenerative power
cell; and
wherein each power cell comprises a chassis, and each chassis in the system has
substantially the same size and shape as the chassis for a plurality of other power cells in the
system.
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9. The system of claim 8, wherein each cell location comprises:
a plurality of support rails;
a power delivery bus positioned to electrically connect with an input bus of a power cell
that is in the cell location; and
a power output bus positioned to electrically connect with an input bus of the power cell
that is in the cell location.
10. The system of claim 8, each regenerative power cell comprises:
an inverter bridge;
a capacitor set electrically connected across terminals of the inverter bridge; and
an active front end comprising a plurality of transistors electrically connected as a three-
phase bridge.
11. The circuit of claim 8, wherein each regenerative power cell comprises:
an inverter bridge;
a capacitor set electrically connected across terminals of the inverter bridge;
a three-phase diode bridge rectifier electrically connected across the terminals; and
a series-connected transistor and resistor combination that is electrically connected across
the terminals.
12. The system of claim 8, wherein each non-regenerative power cell comprises:
an inverter bridge;
a capacitor set electrically connected across terminals of the inverter bridge; and
a three-phase bridge rectifier electrically connected across the terminals.
13. The system of claim 8, further comprising a wire tray that holds control wire for each
power cell.
14

14. A power delivery system, comprising:
a support structure comprising a plurality of cell locations;
at least one regenerative power cell; and
at least one non-regenerative power cell;
wherein the cell locations and power cells are sized and positioned so that each cell
location may interchangeably accept either a regenerative power cell or a non-regenerative power
cell;
wherein each power cell comprises a chassis, and each chassis in the system has
substantially the same size and shape as the chassis for a plurality of other power cells in the
system; and
wherein each cell location comprises a plurality of support rails, a power delivery bus
positioned to electrically connect with an input bus of a power cell that is in the cell location, and
a power output bus positioned to electrically connect with an input bus of the power cell that is in
the cell location
15. The system of claim 14, each regenerative power cell comprises:
an inverter bridge;
a capacitor set electrically connected across terminals of the inverter bridge; and
an active front end comprising a plurality of transistors electrically connected as a three-
phase bridge.
16. The circuit of claim 14, wherein each regenerative power cell comprises:
an inverter bridge;
a capacitor set electrically connected across terminals of the inverter bridge;
a three-phase diode bridge rectifier electrically connected across the terminals; and
15

a series-connected transistor and resistor combination that is electrically connected across
the terminals.
17. The system of claim 14, wherein each non-regenerative power cell comprises:
an inverter bridge;
a capacitor set electrically connected across terminals of the inverter bridge; and
a three-phase bridge rectifier electrically connected across the terminals.
16
18. The system of claim 14, further comprising a wire tray that holds control wire for each
power cell.

A power cell system includes a structure that provides
multiple power cell locations. The system also includes
at least one regenerative power cell, and at least one
non-regenerative power cell. The cell locations and
power cells are sized and position so that each cell
location may interchangeably accept either a
regenerative power cell or a non-regenerative power
cell.

Documents:

00631-kolnp-2008-abstract.pdf

00631-kolnp-2008-claims.pdf

00631-kolnp-2008-correspondence others.pdf

00631-kolnp-2008-description complete.pdf

00631-kolnp-2008-drawings.pdf

00631-kolnp-2008-form 1.pdf

00631-kolnp-2008-form 2.pdf

00631-kolnp-2008-form 3.pdf

00631-kolnp-2008-form 5.pdf

00631-kolnp-2008-gpa.pdf

00631-kolnp-2008-international publication.pdf

00631-kolnp-2008-international search report.pdf

631-KOLNP-2008-(04-07-2014)-ABSTRACT.pdf

631-KOLNP-2008-(04-07-2014)-ANNEXURE TO FORM 3.pdf

631-KOLNP-2008-(04-07-2014)-CLAIMS.pdf

631-KOLNP-2008-(04-07-2014)-CORRESPONDENCE.pdf

631-KOLNP-2008-(04-07-2014)-DESCRIPTION (COMPLETE).pdf

631-KOLNP-2008-(04-07-2014)-DRAWINGS.pdf

631-KOLNP-2008-(04-07-2014)-FORM-1.pdf

631-KOLNP-2008-(04-07-2014)-FORM-2.pdf

631-KOLNP-2008-(04-07-2014)-OTHERS.pdf

631-KOLNP-2008-(04-07-2014)-PETITION UNDER RULE 137.pdf

631-KOLNP-2008-ASSIGNMENT.pdf

631-KOLNP-2008-CORRESPONDENCE OTHERS 1.1.pdf

631-KOLNP-2008-CORRESPONDENCE OTHERS 1.2.pdf

631-KOLNP-2008-CORRESPONDENCE OTHERS 1.3.pdf

631-KOLNP-2008-FORM 13.pdf

631-kolnp-2008-form 18.pdf

631-KOLNP-2008-OTHERS.pdf

631-KOLNP-2008-PCT REQUEST FORM-1.1.pdf

631-KOLNP-2008-PCT REQUEST.pdf

abstract-00631-kolnp-2008.jpg


Patent Number 264337
Indian Patent Application Number 631/KOLNP/2008
PG Journal Number 52/2014
Publication Date 26-Dec-2014
Grant Date 22-Dec-2014
Date of Filing 13-Feb-2008
Name of Patentee SIEMENS INDUSTRY, INC.
Applicant Address 3333 OLD MILTON PARKWAY, ALPHARETTA GEORGIA
Inventors:
# Inventor's Name Inventor's Address
1 AIELLO, MARC F. 1004 5TH STREET, OAKMONT, PENNSYLVANIA 15139
2 ZHANG, XUAN 3414 STONECLIFFE DRIVE MONROEVILLE, PA 15146
PCT International Classification Number H02M 7/00
PCT International Application Number PCT/US2006/034028
PCT International Filing date 2006-08-30
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/713,198 2005-08-31 U.S.A.
2 60/713,197 2005-08-31 U.S.A.
3 11/511,713 2006-08-29 U.S.A.