Description:FIELD OF THE DISCLOSURE
[0001] The present disclosure relates to integration of renewable energy sources and storage
system. More specifically, the present disclosure relates to a multi-high gain multiport
Direct Current to Direct Current (DC-DC) converter for integrating renewable energy
sources with Maximum Power Point Tracking (MPPT) to Direct Current (DC) grids .
BACKGROUND
[0002] The background description includes information that may be useful in understanding the
present invention. It is not an admission that the information provided herein is prior art or
relevant to the presently claimed invention, or that any publication specifically or implicitly
referenced is prior art.
[0003] A growing and persistent demand for renewable energy sources necessitates development
of highly efficient and reliable systems designed to integrate various energy resources
seamlessly. Currently, existing integrating renewable energy sources such as solar, wind,
and fuel cells, along with energy storage systems, typically requires a use of separate
converters. The separate converters result in an increased component count and higher
overall system costs.
[0004] Further the existing integration techniques have interdependency of duty ratios, control
complexity, and a greater number of components are needed. For example charging a 72v
battery using photovoltaic (PV) cells with different voltage and current rate, a wind, and a
fuel cell, requires at least three converters and complicated control methods. Further
existing integration techniques provides low gain and integration of different voltages from
different input sources to a common battery is technically challenging.
[0005] Therefore, there is a need for a to a multi-high gain multiport Direct Current to Direct
Current (DC-DC) converter for integrating renewable energy sources with Maximum
Power Point Tracking (MPPT) to Direct Current (DC) grids.
3
SUMMARY
[0006] Various objects, features, aspects and advantages of the inventive subject matter will
become more apparent from the following detailed description of preferred embodiments,
along with the accompanying drawing figures in which like numerals represent like
components.
[0007] In one aspect of the present embodiment, a multi-high gain multiport Direct Current to
Direct Current (DC-DC) converter for integrating renewable energy sources with
Maximum Power Point Tracking (MPPT) to Direct Current (DC) grids is disclosed. The
high gain DC-DC converter includes at least three energy sources or storages, a plurality
of inductors (L1-L3), a plurality of diodes (D1-D4), and a plurality of power switches (S1-
S4). The energy sources or storages include a first energy source or storage, a second
energy source or storage, and Nth energy source or storage. The plurality of inductors (L1-
L3), the plurality of diodes (D1-D4), and the plurality of power switches (S1-S4) are
configured as boost converter. The energy sources or storage are configured with the boost
converter for transferring one or more input energy from renewable energy sources to the
energy storage system or load or DC grid. The plurality of power switches includes duty
ratios. By adjusting the duty ratios, the DC-DC converter tracks the MPPT from the
renewable energy sources. The DC-DC converter also regulates the renewable energy
sources to maintain an output DC-link voltage.
[0008] According to some embodiments herein, the multi high gain DC-DC converter is
configured with control techniques to manage a power flow between the one or more input
sources, the energy storage system, and the output load.
[0009] According to some embodiments herein, the multi high gain DC-DC converter provides
bidirectional power flow for enabling charging and discharging of the energy storage
system.
[00010] According to some embodiments herein, wherein the bidirectional power flow is
obtained by replacing the plurality of diodes to switches.
4
[00011] According to some embodiments herein, the plurality of inductors is in series with
the plurality of power sources.
[00012] According to some embodiments herein, the control techniques are configured to
provide a control signal to the plurality of switches to transfer energy between the one or
more energy storage or DC grid or load.
[00013] According to some embodiments herein, the converter works Pulse Width
Modulation (PWM) signals with single carrier wave and multiple duty ratios.
[00014] According to some embodiments herein, a duty ratios related to the first energy
source or storage, and the Nth energy source or storage are level shifted below zero.
[00015] According to some embodiments herein, the duty ratios related to second energy
source or storage is level shifted above zero.
[00016] According to some embodiments herein, the duty ratios related to the first energy
source or storage, and the Nth energy source or storage are level shifted above zero when
operated a buck converter.
BRIEF DESCRIPTION OF THE DRAWINGS
[00017] The embodiments herein will be better understood from the following detailed description
with reference to the drawings, in which:
[00018] FIG. 1 illustrates block diagram of a multi-high gain multiport Direct Current to Direct
Current (DC-DC) converter for integrating renewable energy sources with Maximum
Power Point Tracking (MPPT) to Direct Current (DC) grids, according to some
embodiments herein;
[00019] FIG. 2A illustrates an exemplary first circuit diagram of the multi high gain DC-DC
converter with optional second diode (D2), according to some embodiments herein;.
[00020] FIG. 2B illustrates an exemplary first modulation scheme for the first circuit of the multi
high gain DC-DC converter, according to some embodiments herein;
5
[00021] FIG. 3A illustrates an exemplary second circuit diagram of the multi high gain DC-DC
converter, with optional first and second diodes (D1 and D2) according to some
embodiments herein;
[00022] FIG. 3B illustrates an exemplary second modulation scheme for the second circuit of the
multi high gain DC-DC converter, according to some embodiments herein;
[00023] FIG. 4A illustrates an exemplary third circuit diagram of the multi high gain DC-DC
converter, according to some embodiments herein;
[00024] FIG. 4B illustrates an exemplary third modulation scheme for the third circuit of the multi
high gain DC-DC converter, according to some embodiments herein; and
[00025] FIGS. 5A-5B illustrates an exemplary graph results of the first circuit and the second
circuit, as shown in FIG.2A and FIG. 3A, according to some embodiments herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[00026] The following discussion provides many example embodiments of the inventive subject
matter. Although each embodiment represents a single combination of inventive elements,
the inventive subject matter is considered to include all possible combinations of the
disclosed elements. Thus, if one embodiment comprises elements A, B, and C, and a second
embodiment comprises elements B and D, then the inventive subject matter is also
considered to include other remaining combinations of A, B, C, or D, even if not explicitly
disclosed.
[00027] The embodiments herein and the various features and advantageous details thereof are
explained more fully with reference to the non-limiting embodiments that are illustrated in
the accompanying drawings and detailed in the following description. Descriptions of wellknown components and processing techniques are omitted to simplify the embodiments
herein. The examples used herein are intended merely to facilitate an understanding of
ways in which the embodiments herein may be practiced and to further enable those of skill
in the art to practice the embodiments herein. Accordingly, the examples should not be
construed as limiting the scope of the embodiments herein.
6
[00028] Many modifications will be apparent to those skilled in the art without departing from the
scope of the present invention as hereinbefore described with reference to the
accompanying drawings.
[00029] Where a definition or use of a term in an incorporated reference is inconsistent or contrary
to the definition of that term provided herein, the definition of that term provided herein
applies and the definition of that term in the reference does not apply.
[00030] Throughout this specification and the claims which follow, unless the context requires
otherwise, the word “comprise”, and variations such as “comprises” and “comprising”, will
be understood to imply the inclusion of a stated integer or step or group of integers or steps
but not the exclusion of any other integer or step or group of integers or steps.
[00031] As used herein, the singular forms “a”, “an”, “the” include plural referents unless the
context clearly dictates otherwise. Further, the terms “like”, “as such”, “for example”,
“including” are meant to introduce examples which further clarify more general subject
matter and should be contemplated for the persons skilled in the art to understand the
subject matter.
[00032] In some embodiments, the numbers expressing quantities of ingredients, properties such as
concentration, reaction conditions, and so forth, used to describe and claim certain
embodiments of the invention are to be understood as being modified in some instances by
the term “about.” Accordingly, in some embodiments, the numerical parameters set forth
in the written description and attached claims are approximations that can vary depending
upon the desired properties sought to be obtained by a particular embodiment. In some
embodiments, the numerical parameters should be construed in light of the number of
reported significant digits and by applying ordinary rounding techniques. Notwithstanding
that the numerical ranges and parameters setting forth the broad scope of some
embodiments of the invention are approximations, the numerical values set forth in the
specific examples are reported as precisely as practicable. The numerical values presented
in some embodiments of the invention may contain certain errors necessarily resulting from
the standard deviation found in their respective testing measurements.
7
[00033] The recitation of ranges of values herein is merely intended to serve as a shorthand method
of referring individually to each separate value falling within the range. Unless otherwise
indicated herein, each individual value is incorporated into the specification as if it were
individually recited herein. All methods described herein can be performed in any suitable
order unless otherwise indicated herein or otherwise clearly contradicted by context. The
use of any and all examples, or exemplary language (e.g. “such as”) provided with respect
to certain embodiments herein is intended merely to better illuminate the invention and
does not pose a limitation on the scope of the invention otherwise claimed. No language in
the specification should be construed as indicating any non-claimed element essential to
the practice of the invention.
[00034] FIG. 1 illustrates a block diagram 100 of a multi-high gain multiport Direct Current to
Direct Current (DC-DC) converter for integrating renewable energy sources with
Maximum Power Point Tracking (MPPT) to Direct Current (DC) grids, according to some
embodiments herein. The block diagram 100 includes a plurality of energy sources or
storages 102A-102N, the multi high gain DC-DC converter 104, and an energy storage or
DC grid or load106. In a non-limiting example, the plurality of energy sources or storages
102A-102N may be a first energy source or storage 102A, a second energy source or
storage 102B, and Nth energy source or storage 102N. The first energy source or storage
102A may include a wind energy. The second energy source or storage 102B may include
a fuel source. The Nth energy source or storage 102N may include a photovoltaic sources.
Further, through the out specification, the multi high gain multiport DC-DC converter 104
and the DC-DC converter 104 are interchangeably used.
[00035] In an exemplary embodiment, the multi-high DC-DC converter 104 is configured with
control techniques to manage a power flow between the one or more input sources, the
energy storage system, and the output load. The multi high DC-DC converter 104 provides
bidirectional power flow for enabling charging and discharging of the energy storage
system. The bidirectional power flow is obtained by replacing the plurality of diodes (D1-
D3) to switches. Furthermore, for example, the diodes (D1 to D3) are optional, where if
the sources are unidirectional in nature such as the PV, then diodes can be removed. The
8
plurality of inductors is in series with the plurality of power switches. The control
techniques are configured to provide a control signal to the plurality of switches to transfer
energy between the one or more input sources.
[00036] In an exemplary embodiment, the multi high DC-DC converter 104 provides Multi-Input,
Multi-Output Operation. The multi high DC-DC converter 104 may simultaneously handle
inputs from multiple renewable sources and manage the power flow to and from the battery
storage system. The multi high DC-DC converter 104 ensures continuous and reliable
power supply, even when one or more renewable sources are intermittent.
[00037] In an exemplary embodiment, the multi high DC-DC converter 104 provides Maximum
Power Point Tracking (MPPT). Each renewable energy source is equipped with MPPT
capability, which maximizes the energy harvested from solar panels and wind turbines by
continuously tracking and operating at their maximum power points. The MPPT feature
ensures that the multi high DC-DC converter 104 extracts the maximum possible energy
from each source.
[00038] In an exemplary embodiment, the multi high DC-DC converter 104 provides bidirectional
power flow. The multi high DC-DC converter 104 supports bidirectional power flow,
enabling efficient charging and discharging of the battery energy storage system. This
feature is crucial for applications where energy storage is required to balance supply and
demand, provide backup power, or enhance grid stability.
[00039] In an exemplary embodiment, the multi high DC-DC converter 104 provides high voltage
gains. The multi high DC-DC converter 104 is designed to achieve high voltage gains,
making the converter 104 suitable for applications where there is a significant difference
between the input and output voltage levels. The high voltage gain allows for efficient
power conversion and integration of various renewable sources with different voltage
characteristics. In a non-limiting example, the voltage gains are between 0-6.
[00040] In an exemplary embodiment, the multi high gain DC-DC converter 104 includes reduced
number of components. The multi high gain DC-DC converter 104 architecture minimizes
the number of required switches and other components, reducing the overall complexity
9
and cost of the system. Fewer components also mean improved reliability and easier
maintenance.
[00041] In an exemplary embodiment, the DC-DC converter 104 provides operational flexibility.
The DC ports can operate at different voltage levels, allowing the DC-DC converter 104 to
interface with a wide range of renewable energy sources and battery systems. The
flexibility ensures compatibility with various types of equipment and applications.
[00042] In an exemplary embodiment, the DC-DC converter 104 provides simplified Control
Algorithm. The DC-DC converter 104 utilizes a simplified control algorithm to manage
the power flow between the input sources, the battery storage system, and the output load.
The control strategy is designed to be robust and easy to implement, reducing the
computational burden and ensuring stable operation under different conditions.
[00043] FIG. 2A illustrates an exemplary first circuit diagram of the multi high gain DC-DC
converter 104, according to some embodiments herein. The first circuit diagram includes
the input sources, a plurality of inductors (L1-L3), a plurality of diodes (D1-D3), and a
plurality of power switches (S1-S4). The input source comprise the wind energy 102A, the
fuel source 102B, and a first PV source 102N. In a non-limiting example, the plurality of
inductors (L1-L3), the plurality of diodes (D1-D3), and the plurality of power switches
(S1-S4) is configured as one or more boost converters. For the first circuit shown in FIG.
2A, the voltage gain equations are as follows.
?????? =
2??????
1+|????????1|
?????? =
2??????
1-|????????2|
?????? =
2??????????
1-|????????3|
[00044] In an exemplary embodiment, the wind source 102A, the fuel source 102B, and a first
photovoltaic sources 102N are configured with the boost converter for transferring energy
to the energy storage system.
[00045] FIG. 2B illustrates an exemplary first modulation scheme for the first circuit of the multi
high gain DC-DC converter 104, according to some embodiments herein. The first
modulation scheme switches between the first photovoltaic sources, the fuel source, and
the wind source to achieve a required output voltage. Further the first modulation scheme
10
sends control signals to the first photovoltaic sources, the fuel source, and the wind source
for the MPPT. The carrier wave is a triangular with 1 to -1 as peak values. The modulation
schemes presented in FIG.2B uses fuel cell source to maintain DC link voltage and extracts
maximum power from wind and solar. Furthermore, the converter maintains DC link
voltage and also extracts maximum power from PV and wind energy sources.
[00046] FIG. 3A illustrates an exemplary second circuit diagram of the multi high gain DC-DC
converter 104, according to some embodiments herein. The second circuit diagram
includes the wind source 102A, the first photovoltaic sources, and a second photovoltaic
sources (PV) 102N. The second photovoltaic sources, and the wind source are configured
with the boost converter for transferring energy to the energy storage or DC grid or load
106. For the second circuit shown in FIG. 3A, the voltage gain equations are as follows.
?????? =
2??????1
1+|????????1|
?????? =
2??????2
1-|????????2|
?????? =
2??????????
1-|????????3|
[00047] FIG. 3B illustrates an exemplary second modulation scheme for the second circuit of the
multi high gain DC-DC converter 104, according to some embodiments herein. The second
modulation scheme sends control signals to the first and second photovoltaic sources, the
wind source to operate in MPPT mode. The converter extracts maximum power from all
the sources and feed to energy storage or DC grid or load 106.
[00048] FIG. 4A illustrates an exemplary third circuit diagram of the multi high gain DC-DC
converter 104, according to some embodiments herein. The third circuit diagram includes
a load/battery in place of the wind source 102A, the first photovoltaic sources or the fuel
source, and the second photovoltaic sources 102N. The first photovoltaic sources or the
fuel source, and the second photovoltaic sources or any other source, are configured as
boost converter for transferring energy to the energy storage or DC grid or load 106. The
converter D4 and S4 are exchanged to feed secondary load or secondary storage with
reduced gain. For the third circuit shown in FIG. 4A, where there is buck operation, the
voltage gain equations are as follows.
?????? =
2??????1
1+|????????1|
?????? =
2??????2
1-|????????2|
?????????? =
(1-|????????3|) ??????
2
11
[00049] FIG. 4B illustrates an exemplary third modulation scheme for the third circuit of the multi
high gain DC-DC converter 104, according to some embodiments herein. The third
modulation scheme where wind source 102A is replaced with load/battery, the first
photovoltaic sources or the fuel source, and the second photovoltaic sources 102N to
achieve a required output voltage. Further the second modulation scheme sends control
signals to the second photovoltaic source for the MPPT and also performs buck operation
for the load/battery connected in place of wind source 102A. The converter maintains DC
link voltage using first source, extract maximum power from second source and also
feeds/charges a secondary load/storage.
[00050] In addition, maximum powers can be extracted from at least two PV sources and send to
energy storage or DC grid or load 106, buck operation for third port.
[00051] FIGS. 5A-5B illustrates an exemplary graph results of the first circuit and the second
circuit, as shown in FIG.2A and FIG. 3A, according to some embodiments herein. The
graph results of the modulation schemes shows output power waveforms for each the wind
source 102A, the fuel source 102B, the first photovoltaic sources, and the second
photovoltaic sources 102N and the energy storage or DC grid or load 106.
[00052] FIG. 5A shows the converter maintains DC-link power using first fuel cell while extracting
maximum powers from PV and wind at varying irradiations and wind speed scenarios.
FIG. 5B shows the converter extracting maximum power from three sources and charging
the battery at common DC-link.
[00053] An advantage of the present disclosure is that the multi high DC-DC converter 104 charges
a battery or supply a load from the plurality of input sources 102A-102N and also extracts
maximum powers (MPPT mode) from all the sources with appropriate gains.
[00054] An advantage of the present disclosure is that the number of switches and components
required in the multi gain DC-DC converter 104 is reduced.
[00055] An advantage of the present disclosure is that the input sources may be operated with
different voltages.
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[00056] An advantage of the present disclosure is that depending on a requirement all the ports can
be made bidirectional by replacing the diodes with switches. In addition, the diodes can be
eliminated/removed if the sources are unidirectional like solar PV.
[00057] An advantage of the present disclosure is that all the energy sources or storages are MPPT
operatable.
[00058] While various examples of the present disclosure have been described above, it should be
understood that they have been presented by way of example, and not limitation. Thus, the
breadth and scope of the present disclosure should not be limited by any of the abovedescribed examples but should be defined in accordance with the following claims and
their equivalent

, Claims:We claim:
1. A multi-high gain multiport Direct Current-Direct Current (DC-DC) converter (104) for
integrating renewable energy sources with a Maximum Power Point Tracking (MPPT) to
a Direct Current (DC) Load, the multi gain DC-DC converter comprising:
at least three energy sources or storages (102A-102N), wherein the energy sources
or storages (102A-102N) comprise a first energy source or storage (102A), a second energy
source or storage (102B), and a Nth energy source or storage (102N),
a plurality of inductors (L1-L3);
a plurality of diodes (D1-D4); and
a plurality of power switches (S1-S4) that is configured as boost or buck converters,
wherein the wind source (102A), the fuel source (102B), and the at least two
photovoltaic source (102N) are configured with the boost converter for transferring one or
more input energy from renewable energy sources to the energy storage system 106,
wherein the plurality of power switches (S1-S4) comprises duty ratios,
wherein by adjusting the duty ratios, the DC-DC converter (104) tracks the MPPT
from the renewable energy sources (102A-102N),
wherein the DC-DC converter (104) regulates the renewable energy sources to
maintain an output DC-link voltage.
2. The multi-high gain multiport DC-DC converter (104) as claimed in claim 1, wherein the
DC-DC converter is configured with control techniques to manage a power flow between
the one or more input sources, the energy storage system, and the output load.
3. The multi-high gain multiport DC-DC converter (104) as claimed in claim 1, wherein the
DC-DC converter provides bidirectional power flow for enabling charging and discharging
of the energy storage system.
4. The multi-high gain multiport DC-DC converter (104) as claimed in claim 3, wherein the
bidirectional power flow is obtained by replacing the plurality of diodes to switches.
14
5. The multi-high gain multiport DC-DC converter (104) as claimed in claim 1, wherein the
plurality of inductors is in series with the plurality of power switches.
6. The multi-high gain multiport DC-DC converter (104) as claimed in claim 1, wherein the
control techniques are configured to provide a control signal to the plurality of switches to
transfer energy between the one or more energy storage or DC grid or load (106).
7. The multi-high gain multiport DC-DC converter (104) as claimed in claim 1, wherein the
output DC-link voltage comprises one Pulse Width Modulation (PWM) signal with
triangular wave varies between 1 and -1.
8. The multi-high gain multiport DC-DC converter (104) as claimed in claim 1, wherein a
duty ratios related to the first energy source or storage (102A), and the Nth energy source
or storage (102N) are level shifted below zero.
9. The multi-high gain multiport DC-DC converter (104) as claimed in claim 1, wherein the
duty ratios related to second energy source or storage (102B) is level shifted above zero.
10. The multi-high gain multiport DC-DC converter (104) as claimed in claim 1, wherein the
duty ratios related to the first energy source or storage (102A), and the Nth energy source
or storage (102N) are level shifted above zero when operated a buck converter