U.S. patent application number 15/321420 was filed with the patent office on 2018-02-15 for wide range power combiner.
The applicant listed for this patent is ARGENTUM ELECTRONICS, INC.. Invention is credited to Bolis IBRAHIM, Kamil WYSZYNSKI, Oleh ZHYHINAS.
Application Number | 20180048148 15/321420 |
Document ID | / |
Family ID | 58051398 |
Filed Date | 2018-02-15 |
United States Patent
Application |
20180048148 |
Kind Code |
A1 |
IBRAHIM; Bolis ; et
al. |
February 15, 2018 |
WIDE RANGE POWER COMBINER
Abstract
A wide range power combiner (WRPC) includes an electronics
system that combines power from a plurality of input sources, which
can differ in level, to at least a single output. In certain
embodiments, a circuit can be constructed as shown in the figures
(FIG. 1); a controller is used to generate a control signal to the
switches, and for monitoring the energy storage elements. A
possible control signal to the switches is shown in the figures
(FIG. 2). The control signal, or signals, can dynamically change
the frequency and order of switching to cause the switches to
change the electrical connections of the energy storage elements,
between the input and the output or outputs. A possible dynamic
control algorithm is shown in the figures (FIG. 4). Switches can be
any electrical switch, including transistors and relays. Energy
storage elements can be any energy storage element, including
capacitors and inductors.
Inventors: |
IBRAHIM; Bolis; (Toronto,
CA) ; ZHYHINAS; Oleh; (Toronto, CA) ;
WYSZYNSKI; Kamil; (Toronto, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ARGENTUM ELECTRONICS, INC. |
Toronto |
|
CA |
|
|
Family ID: |
58051398 |
Appl. No.: |
15/321420 |
Filed: |
August 18, 2016 |
PCT Filed: |
August 18, 2016 |
PCT NO: |
PCT/IB2016/054938 |
371 Date: |
December 22, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62206270 |
Aug 18, 2015 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02J 1/12 20130101; G05F
1/66 20130101; H02J 1/10 20130101 |
International
Class: |
H02J 1/12 20060101
H02J001/12; G05F 1/66 20060101 G05F001/66 |
Claims
1) A wide range power combiner (WRPC) system comprising: a
plurality of input power sources; a set of energy storage elements,
with at least two energy storage elements per power source, such
that each of the energy storage elements can be connected to a
power source or an output or outputs; a set of switches, connecting
the energy storage elements to the input power sources and the
output(s); at least one measurement device, for the measurement of
energy storage elements; a controller comprising: a control loop
for the system, wherein the control loop learns the maximum power
point for each power source, and connects and disconnects different
storage elements to and from the system output; systems constraints
for managing limitations to maintain energy output, voltages,
currents, and other variables within system parameters.
2) The WRPC system in claim 1, where the energy storage elements
are provided in at least a 2:1 ratio of storage elements to power
sources.
3) The WRPC system in claims 1-2 where the energy storage elements
are substantially identical.
4) The WRPC system in claims 1-3 where input power of each source
is controlled to achieve the maximum power point of that source
5) The WRPC system in claims 1-4 where in maximum power point is
detected automatically by the system controller.
6) The WRPC system in claims 4 and 5 where the controller is
configured to measure the energy stored in the energy storage
elements, to determine the output power of the power sources.
7) The WRPC system in claim 6, where the controller uses voltage
measurements and the properties of the energy storage element to
calculate the energy stored in the energy storage element.
8) The WRPC system in claims 1-7 where all but one of the energy
storage elements are each connected to their respective input power
sources, and all but one of the input power sources each being
connected to at least two energy storage elements.
9) The WRPC system in claims 1-8 where the controller selects which
energy storage element to connect to the output, in order to
maintain the maximum power point of each input power source.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to the combination of
multiple DC power sources, and more particularly to the combination
of multiple DC power sources that have different voltage, current,
or maximum power points, into at least a single output.
BACKGROUND ART
[0002] Combining multiple power sources of different voltages or
currents efficiently can be a challenge in the field of
electronics. When power sources are combined in series, they may
not have the same current at the maximum power point, and since the
current must be equal across all sources, one or all will not be
operating at their respective maximum power point. Alternatively,
if power sources are combined in parallel, they may not have the
same voltage at the maximum power point. Since the voltage across
all power sources must be the same in a parallel configuration,
some or all of the power sources may not be operating at their
respective maximum power point.
[0003] Various topologies have been developed to connect multiple
power sources to a load, and fall under several categories. One
category is the individual control and regulation of each power
source, of which one example is in the Patent Literature 1. Each
power source has a maximum power point tracking (MPPT) module
connected to it, with the outputs of the MPPT modules connected
together. The output voltage of the each MPPT module is regulated
to the output of the string. Various topologies for the MPPT
modules, various control methods, and various connections between
MPPT modules exist.
[0004] Another method to combine power sources is to connect them
together through a transformer, with each power source having
windings around a common core. This method is fundamentally a
buck-boost type dc-dc converter system with the inductor being
substituted with a transformer, which has multiple input windings.
An example of one such system is described in the Non Patent
Literature 1. There are various implementations of this system,
which have different configuration of the windings, DC-DC
regulation, and control systems.
CITATION LIST
Patent Literature
[0005] [PTL 1] PCT patent application No. PCT/US2013/064477
Non Patent Literature
[0006] [NPL 1] H. Matsuo et al., "Characteristics of the
Multiple-Input DCDC Converter," IEEE Trans. Ind. Electron., vol.
IE-51, pp. 625-631, June 2004.
DISCLOSURE OF INVENTION
[0007] A system for the combination of multiple input power sources
into at least a single output is provided. The electronics system
maximizes the power of the output or outputs, from a plurality of
input power sources. In certain embodiments, the electronics system
may be used with any suitable power source at the inputs, including
photovoltaics, wind turbines, and batteries. The electronics system
is able to detect the power produced by each power source,
intelligently monitor the input, and switch the configuration of
energy storage elements. The switches change the electrical
connections of the energy storage elements between the input and
the output or outputs. The system operates in order to obtain the
maximum power from each of the sources, for any environmental
conditions.
[0008] The advantages of using this system may be to provide an
alternative to connecting power sources in series or parallel, that
vary in voltage or current output, in order to avoid power losses.
This advantage may be observed when the system is used with
photovoltaics, where sources of inefficiency, including uneven
cloud cover, can cause the power outputs of a plurality of cells to
be mismatched. The advantages of this system over the current art
include the decreased number of components, design simplicity, and
the absence of expensive components such as transformers or
inductors.
[0009] The WRPC system comprises a plurality of power sources, the
electronics switching system, the energy storage elements,
measurement device(s), and the controller. The controller is used
to control switches and take measurements from the energy storage
elements.
[0010] In some embodiments, the controller is an intelligent
controller that utilizes control algorithms. The controller
monitors input from the energy stored in the energy storage
elements, and the controller intelligently switches the
configuration of the connections of the energy storage elements,
between the input power sources and the output or outputs, in such
a way as to ensure the maximum power output from each source.
[0011] In some embodiments, the method of operation of the device
is that each power source has two energy storage elements which are
charged by the power source. Each energy storage element has an
input switch connecting it to its power source, and an output
switch connecting it to the output or outputs. The system can
disconnect any one of the energy storage elements from the power
source to connect it to the output. While one of the energy storage
elements is connected to the output, the power source continues to
charge the other energy storage element(s). The other power sources
whose energy storage elements are not connected to the output,
continue to charge both energy storage elements. In some
embodiments, more than two energy storage elements per power source
may be used. In some embodiments, an energy storage element can be
used at the output to smooth variances in the voltage.
[0012] In some embodiments, the controller will use information
about the amount of energy stored in the energy storage elements to
determine the charge rate of the elements. The maximum power point
of the source is found by searching for the voltage that produces
the highest charge rate of the energy storage elements. This is
carried out such that the search space is within the tolerances of
the energy storage elements and the switching system, and the
maximum and minimum desired output power or voltage.
[0013] In some embodiments the switches are controlled in such a
way that the inputs are isolated from one another through time
division multiplexing.
BRIEF DESCRIPTION OF DRAWINGS
[0014] FIG. 1 illustrates a block diagram of an embodiment of the
wide range power combiner (WRPC) switching system.
[0015] FIG. 2 Illustrates one period of an unoptimized switch
timing diagram, where each energy storage element is individually
connected to the output, in sequence.
[0016] FIG. 3 Illustrates an example of the maximum power point of
an input power source to the wide range power combiner (WRPC)
[0017] FIG. 4 Illustrates a block diagram of an intelligent control
algorithm that can be utilized by the controller, to control the
wide range power combiner (WRPC) switching system.
BEST MODE OF CARRYING OUT INVENTION
[0018] Embodiments of the invention are described more fully
hereinafter with reference to the drawings.
[0019] In some embodiments the switches may be transistors, and the
energy storage elements may be capacitors.
[0020] In the case of two energy storage elements per power source,
as shown in FIG. 1, each storage element is connected to the power
source through an input switch. Each switch is controlled
independently by the controller. When the switch between the power
source and the capacitor is closed the energy storage element will
be charged by the power source.
[0021] Every storage element is also connected to the output
through a switch. When the energy storage element is being charged
from the power source, the output switch will be open, and the
energy storage element will be disconnected from the output. When
an energy storage element is connected to the output, the input
switch will be open, and the energy storage element will be
disconnected from the power source. While the energy storage
element is providing power to the output, the power source
continues to charge the second energy storage element. Only one
energy storage element is connected to the output at a time.
[0022] Due to limitations of MOSFETs, proper considerations need to
be taken to ensure that no current is conducted between energy
storage elements across different input power sources.
[0023] The timing of the switches is controlled by a controller. In
some embodiments the controller can be a micro controller. The
controller can control the switches using a timing diagram as in
FIG. 2, where one period of switching is shown, or the controller
can utilize an intelligent control algorithm to ensure efficient
operation and ensuring that each input power source is operating at
its maximum power point. A control algorithm is described
below.
[0024] The energy in the capacitors is measured by measuring the
voltage, and using the known capacitance according to the
formula:
E=1/2*C*V2
[0025] Where E is the total energy stored in Joules, C is the
capacitance of the capacitor in Farads, and V is the measured
voltage in Volts. The change in energy in the energy storage
element(s) would be equal to the output power of the power source.
This can be used to determine the maximum power point of the power
source, because as the voltage of the capacitor increases, the rate
of charge will also change as shown in FIG. 3.
[0026] Once the maximum power point of the source is found, the
controller will intelligently select the energy storage element
which must be connected to the output. This selection is made to
ensure that the voltage of each energy storage element remains at
the voltage of the maximum power point of its input power source.
An example of such a control algorithm is shown in FIG. 4.
[0027] In the control algorithm of FIG. 4, an energy storage
element is selected, and if it has not yet been measured, the
voltage of the selected energy storage element is measured. This is
repeated until the voltage of all energy storage elements have been
measured. Next, the difference between the voltage of each storage
element and the voltage at the maximum power point of its source is
determined. The energy storage element that is currently connected
to the output is disconnected, and then connected to its power
source. The energy storage element with the largest difference,
that also has a greater voltage than that of the maximum power
point of its input power source, is then disconnected from its
power source and connected to the output. All stored measurement
values are cleared and the controller begins the process of
selecting the next energy storage element, to connect to the
output, from the beginning.
[0028] A dynamically changing load can be used at the output of the
wide range power combiner (WRPC) to ensure that all input power
sources are operating at their maximum power point. A DC-DC
converter can be used to dynamically change the apparent output
load of the wide range power combiner. A DC-DC converter can be a
boost converter. If the boost converter is intelligently
controlled, at a frequency that is relatively high in comparison to
that of the switching frequency of the WRPC switching system, it
can adapt to the changes in the WRPC output. The use of the DC-DC
converter at the output of the WRPC can provide a fixed DC output
voltage.
* * * * *