FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
AND
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
A multistage load demand-dependant adaptive power management system
for charging battery
APPLICANTS:
Crompton Greaves Limited, CG House, Dr. Annie Besant Road, Worli, Mumbai - 400030, Maharashtra, India, an Indian Company
INVENTORS:
Wachasundar Shripad of Crompton Greaves Limited, Global R&D, Electronic Design Centre (EDC), Aryabatta Building, Kanjur Marg (East), Mumbai -400042, Maharashtra, India; an Indian National.
PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:

FIELD OF THE INVENTION:
This invention relates to the field of power management systems, and computational systems for power management, thereof.
Particularly, this invention relates to power charging systems and methods thereof
Specifically, this invention relates to a multistage load demand-dependant adaptive power management system for charging battery.
BACKGROUND OF THE INVENTION:
From the onset of the 20th and 21st century, it has been a constant endeavour of human kind to depart from dependence of fossil fuels as sources of energy to renewable sources of energy. Renewable sources of energy are not only cleaner but also provide an unlimited source.
Solar power is a renewable source of energy, which has become increasingly popular in modern times. It has obvious advantages over non-renewable energy sources, such as coal, oil, and nuclear energy. However, there is a drawback to solar power - energy can only be produced when the sun shines. To overcome this, usually solar panels are coupled with back up rechargeable batteries, which can store excess power generated during the day and use it to provide energy to systems when there is no sunlight or sunshine. In this way, solar power can be used to power houses and other large scale systems.
A photovoltaic (PV) solar panel is ordinarily arranged as an array of cells that directly convert solar energy into electrical energy. PV arrays essentially consist

of a number of internal silicon based photovoltaic cells combined in series, and in parallel, depending on the voltage or current requirements. These cells are used to convert solar energy into electricity. This occurs when the photovoltaic cells are exposed to solar energy causing the cells electrons to drift which, in turn, produces an electric current. This current varies with the size of individual cells and the light intensity.
Solar photovoltaic systems are conventionally arranged to supply charging (or recharging) power to storage batteries, such as rechargeable lead-acid or nickel cadmium battery systems. Maximum Power Point Tracking (MPPT) is generally used in photovoltaic systems to maximize the photovoltaic array output power, irrespective of the temperature, irradiation conditions, and electrical characteristics of the load. Maximum Power Point Tracking is a technique that solar battery chargers use to get the maximum possible power from one or more photovoltaic devices.
In some circumstances, the electric power supplied from the solar energy is lower than that required by loads. Accordingly, the systems of solar energy are equipped with batteries and a battery-charging device. In order to effectively utilize the electric power stored in batteries, the power generated from the solar energy must rapidly and efficiently charge the batteries which can be performed as an electric power source of loads.
In a conventional charging method of a storage battery, a continuous MPPT-charging scheme is adopted. Such arrangements generally include a DC-DC power converter that is under control by a digital signal processor that controls the duty cycle of the power converter in an attempt to maximize the power delivered to the battery or batteries being charged. During the charging period, the MPPT function is retained to achieve high charging efficiency. However,

such rapid, improper and overcharging of the battery may cause damage to batteries and may shorten the life of the battery.
Furthermore when load connected to the system increases or decreases, the system tries to adjust as per the requirement of the load; however such adjustment may adversely affect the battery charging process.
Therefore, there has been a persistent need to devise a power system for effectively charging the batteries and simultaneously taking care of the fluctuations in the load.
PRIOR ART:
US2010123428 discloses a pulsed and MPPT charging technique. This is a 2-stage battery charging system. Here, MPPT is used only when load demand is greater than maximum power that can be delivered by pulse charging, means no secondary source for load. In this prior art, load demand is constant quantity and according to Photo Voltaic (PV) generated pulse charging is controlled, if it is not able to provided by pulse charging then operating point shifts to MPPT. It always tries to operate at pulse charging mode when PV power less and if pulse charging mode cannot able to supply that power, then it moves to MPPT. Flexibility of operating point is from Pulsed to MPPT only,
US20100263711 discloses a Maximum power point tracking control apparatus for a solar battery. Here, there is no optimum utilization of solar power. It always takes care of battery charging only. Furthermore, there is no flexibility of operating point. Also, no load variants are considered.

US6204645 discloses a battery charging controller which comprises Buck topology power conversion. This prior art discloses the controller for a solar electric generator so as to extract maximum power capacity from solar panels and this depends on state of charge of battery. But there is no concept of operating at a MPPT mode. Also, battery is the only load here, there is no external load management and nowhere load variants are considered. Power from PV panel will be first stored in storage device (Capacitor) and depending on state of charge of battery, this storage device will output the power to battery. This results in loss of energy as capacitor which is acting as a storage device has some discharge within it. Because of complex circuitry and number of components, energy from PV panels will be wasted. Three stage charging topology given in this prior art is very generic and is the basic method of battery charging and this three stage charging is not for operating at MPPT. There is no flexibility of operating point when battery in floating stage of charging.
The limitations of the prior art need to be overcome.
OBJECTS OF THE INVENTION:
An object of the invention is to provide a system and a method for harnessing solar power to charge a battery and drive a load in an adaptive manner.
Another object of the invention is to provide a system and a method for effectively charging the batteries and simultaneously taking care of the fluctuations in the load.
Yet another object of the invention is to efficiently use solar power through photo voltaic panels and more importantly to efficiently distribute power

available through the photo voltaic panels in a dynamic load adaptive and battery adaptive manner.
Still another object of the invention is to efficiently charge a battery through photo voltaic panels and eliminate overcharging of battery, thereby lengthening the battery life which was previously (in prior art) caused due to rapid charging and overcharging without actual feedback from the system and method.
An additional object of the invention is to provide a system and a method in order to intake feedback from load as well as battery in a dynamic adaptive manner in order to provide an optimum solution for charging from photo voltaic panels.
Yet an additional object of the invention is to provide a system and a method for driving a load through power from photo voltaic panels, in that, the system and method accommodates for fluctuations in load.
SUMMARY OF THE INVENTION:
According to this invention, there is provided a multistage load demand-dependant adaptive power management system for charging battery comprises:
a. at least a battery sensor adapted to sense battery condition;
b. at least a loads' sensor adapted to sense load condition;
c. at least a first voltage defining means adapted to define a first pre-defined
voltage value in order to invoke a first function of charging in order to
start charging the battery;
d. at least a second voltage defining means adapted to define a second pre
defined voltage value in order to invoke a second function of charging in
order to continue charging of the battery;

e. at least a first current defining means adapted to define a first pre-defined current value in order to invoke a third function of charging in order to continue charging of the battery as well as to drive the load / mains;
f at least a third voltage defining means adapted to define a third predefined voltage value in order to invoke a fourth function of charging and also the second function with very less current; and
g. at least a determination mechanism adapted to determine a state of mode of operation of the system and method depending upon sensed load condition and sensed battery condition in correlation with first predefined voltage, second pre-defined voltage, third pre-defined voltage, and fourth pre-defined voltage, characterized, in that, said state of mode of operation is at least a mode selectable from a group of modes consisting of at least a Maximum Power Point Tracking mode, at least a Constant Voltage mode, at least a Constant Current mode, and at least a Float mode.
Typically, said first pre-defined voltage value is a pre-defined lower limit voltage of a battery which qualifies the battery as a deeply discharged battery
Typically, said first function is a Maximum Power Point Tracking function.
Typically, said second pre-defined voltage value is an upper limit which is greater than the first pre-defined voltage value limit but lesser than a final predefined maximum terminal voltage value limit.
Typically, said second function is a Constant Voltage function.
Typically, said first pre-defined current value is a lower limit.

Typically, said third function is a Constant Current function.
Typically, said third pre-defined voltage is a pre-defined final (maximum terminal) voltage limit.
Typically, said fourth function is a Float Mode function.
Typically, said second pre-defined voltage being at least 80% of battery charge.
Typically, said system comprises a Maximum Power Point Tracking mechanism adapted to operate said system in said Maximum Power Point Tracking mode, characterised, in that, said battery being charged with maximum power when said sensed battery condition is at or below said first pre-defined voltage until said sensed battery condition reaches said second pre-defined voltage.
Typically, said system comprises a Constant Current mechanism adapted to operate said system in Constant Current mode, characterised, in that, said battery breaching said first pre-defined current value until said battery condition reaches said third pre-defined voltage value.
Typically, said system comprises a Constant Voltage mechanism adapted to operate the system in Constant Voltage mode, characterised, in that, said battery being maintained at said third pre-defined voltage value.
Typically, said system comprises a Float mechanism adapted to operate said system in Float mode, characterised, in that, said battery being almost charged and state of charge of batteries is well beyond the second pre-defined voltage.
Typically, said system comprises at least an insulation sensor adapted to sense insulation variation.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
The invention will now be described in relation to the accompanying drawings, in which:
Figure 1 illustrates a schematic block diagram depicting how power supplied from Photo Voltaic panels drives the load and the remaining power charges the batteries;
Figure 2 illustrates a graphical representation for multi stage battery charging from Photo Voltaic panels;
Figure 3 illustrates a graphic representation of adaptive input power management from Photo Voltaic panels for respective changes in load demand; and
Figure 4 illustrates a flow chart for selecting which mode system should operate.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
According to this invention, there is provided a multistage load demand-dependant adaptive power management system for charging battery. Typically, the load conditions may be dynamic in nature, in that, they may be dynamically changing.
Figure 1 illustrates a schematic block diagram depicting how power supplied from Photo Voltaic panels drives the load and the remaining power charges the batteries.

Here power supplied from PV panels is driving the load and the remaining charging the batteries.
Photo Voltaic panels (PV) drive a solar battery charger (SBC). Output from the solar battery charger (SBC) is provided to load (L) as well as to batteries (B). The power to load (L) from solar battery charger (SBC), according to at least one embodiment, is through an inverter (I)
Figure 2 illustrates a graphical representation for multi stage battery charging from Photo Voltaic panels.
In accordance with an embodiment of this invention, there is provided a battery sensor adapted to sense battery condition. A state of charge of battery is determined by this battery sensor. This state of charge sensing may be continuous or discrete, as pre-defined.
In accordance with another embodiment of this invention, there is provided a loads' sensor adapted to sense load condition. Load condition may be requirement of load. This state of charge sensing may be continuous or discrete, as pre-defined.
In accordance with yet another embodiment of this invention, there is provided an insulation sensor adapted to sense insulation variation.
In accordance with an embodiment of this invention, there is provided a first voltage defining means adapted to define a first pre-defined voltage. Typically, the first pre-defmed voltage is a pre-defined lower limit voltage of a battery which qualifies the battery as a deeply discharged battery in order to invoke a

first function of charging in order to start charging the battery. Typically, the first function is a Maximum Power Point Tracking function.
In accordance with another embodiment of this invention, there is provided a second voltage defining means adapted to define a second pre-defined voltage. Typically, the second pre-defined voltage is an upper limit which is greater than the first pre-defined voltage limit but lesser than a final pre-defined maximum terminal voltage limit in order to invoke a second function of charging in order to continue charging of the battery. Typically, the second function is a Constant Voltage function.
In accordance with yet another embodiment of this invention, there is provided a first current defining means adapted to define a first pre-defined current. Typically, the first pre-defined current is a lower limit in order to invoke a third function of charging in order to continue charging of the battery as well as to drive the load / mains. Typically, the third function is a Constant Current function.
In accordance with still another embodiment of this invention, there is provided a third voltage defining means adapted to define a third pre-defined voltage.
Typically, the third pre-defined voltage is a pre-defined final (maximum terminal) voltage limit in order to invoke a fourth function of charging and also the second function with very less current as battery / batteries are almost charged and state of charge of batteries, to be maintained, is pre-defined.
Typically, the fourth function is a Float Mode function.

In accordance with another embodiment of this invention, there is provided a determination mechanism adapted to determine a state of mode of operation of the system and method depending upon sensed load condition and sensed battery condition in correlation with first pre-defined voltage, second predefined voltage, third pre-defined voltage, and fourth pre-defined voltage. A state of mode of operation is selectable from a group of modes consisting of at least a Maximum Power Point Tracking mode, at least a Constant Voltage mode, at least a Constant Current mode, and at least a Float mode.
In accordance with still another embodiment of this invention, there is provided a Maximum Power Point Tracking mechanism adapted to operate the system and method of this invention in Maximum Power Point Tracking (MPPT) mode. When battery condition is deeply discharged, the batteries need to be charged with maximum power that can be supplied from photo voltaic panels. Hence, the system always tries to operate in Maximum Power Point Tracking mode. In Maximum Power Point Tracking mode of operation, the system and method make the operating point to operate at a Maximum Power Point. Here, battery condition is deeply discharged. Hence, irrespective of load conditions, it tries to operate at maximum power point. The system and method will operate continuously, in this mode, till state of charge of battery reaches the second predefined voltage. Typically, this second pre-defined voltage may be about 80% of battery charge.
In accordance with an additional embodiment of this invention, there is provided a Constant Current mechanism adapted to operate the system and method of this invention in Constant Current (CC) mode. Once first pre-defined current is breached, the system and the method operates with constant current mode. In this mode, charging current of the battery is maintained within the first pre-defined current. So, as time goes by, the terminal voltage of the battery '

increases. In this mode of operation, system operates in blue coloured marked region. The system and method of this invention will operate in this mode until maximum terminal voltage limit of battery is reached. After this, the system and method proceeds to Constant Voltage (CV) mode.
In accordance with yet an additional embodiment of this invention, there is provided a Constant Voltage mechanism adapted to operate the system and method of this invention in Constant Voltage (CV) mode. In this mode, output of the charge controller is maintained at third pre-defined voltage. Hence, as time goes by, charging current starts decreasing as internal resistance of the batteries increases. In this mode of operation, system and method operate in blue coloured region. The system and method of this invention operates, in this mode, continuously till first pre-defined voltage is reached. It maintains a constant converter output voltage and converter output current starts decreasing as battery voltage increases. When battery charging current reaches below first pre-defined voltage limit, it will go to constant current (CC) mode with minimum charging current limit.
In accordance with still an additional embodiment of this invention, there is provided a Float mechanism adapted to operate the system and method of this invention in Float (F) mode. Once the third pre-defined voltage is reached, system and method starts to operate in float (F) mode. Also, it operates in constant voltage (CV) mode, but charges with very less current, at this stage, as batteries are almost charged and state of charge of batteries is well beyond the second pre-defined voltage i.e. above 95%. The system and method of this invention operates continuously, in this mode, and this current starts decreasing. The system and method maintains a constant converter output battery charging current and converter output voltage starts increasing. After it reaches to

maximum limit of battery voltage, the system and method switches to constant voltage (CV) mode, and it runs with float (F) condition.
Figure 3 illustrates a graphic representation of adaptive input power management from Photo Voltaic panels for respective changes in load demand.
The system and method of this invention always monitors the power drawn by load and also state of charge of the battery. If state of charge of the battery is >80%, then system will operate anywhere in blue coloured region in either of the three modes, CV, CC, and float modes.
When the load increases and state of charge of battery is beyond the second predefined voltage, the system and method of this invention determines its mode of operation as Maximum Power Point Tracking (MPPT) mode so that:
i) Load demand is reached; and
ii) It keeps the rate of charging of battery maintained as constant.
Additionally, if load demand increases, system and method operates at Maximum Power Point Tracking (MPPT) mode and battery starts discharging so that demanded load power is reached. At this stage, load power is contributed by battery and photo voltaic panels.
When the load decreases and state of charge of battery is beyond the second pre-defined voltage, the system and method of this invention determines its mode of operation shifts towards blue colours region of Figure 3 of the accompanying drawings so that the system and method maintains required charging current and load demand is reached. Still, if load demand power decreases, system operates at initial stage of charging.

When the state of charge of battery is beyond the second pre-defined voltage and system is in NO-LOAD, the batteries are charging with constant voltage (CV) mode. Typically, according to at least one embodiment, a 200W load is added on load side, then operating point of operating mode shifts towards Maximum Power Point Tracking (MPPT) mode. As load increases by increments of 200W, the operating point shifts towards Maximum Power Point Tracking (MPPT) mode and after adding above 800W, battery starts to discharge and system continues its operation with Maximum Power Point Tracking (MPPT) mode, so that, without wasting the solar power, even after batteries are charged. As load on inverter decreases, operating point moves to initial state from Maximum Power Point Tracking (MPPT) mode.
Figure 4 illustrates a flow chart for selecting which mode system should operate.
Step 1: reading of sensing variables;
Step 2: based on battery voltage and loading condition, determination
mechanism chooses mode of operation of system and method. This depends on
status of the variables. The modes of operation are selected from MPPT, CC,
CV, CV to CC, and Float;
Step 3a: MPPT mode;
Step 3b: CC mode with limits defined by variables CV to CC mode and CC
mode;
Step 3c: CV mode with limits defined by variables CV and float;
Step 4: Depending on loading condition, insulation variation and battery voltage
status of the variables will change, accordingly modes of operation also
switches.

The technical advancement of this invention lies in providing a power charging system from photovoltaic modules (using solar energy) in order to drive a load / mains and also to (simultaneously) charge a battery using in order to drive the load / mains in the absence of solar energy; irrespective of the duty cycles of battery charge-discharge and in a effective efficient manner such that overcharging of battery is avoided and such that batter life is not shortened. This invention takes into consideration various pre-defined voltage and current levels of the battery in order to allow the power charging system to alternate between maximum power point tracking mode, constant voltage mode, constant current mode, and float mode; in correspondence with pre-defined logic of alternation.
The technical advancement of this invention further lies in:
• Providing various modes of driving a load and a battery from solar irradiation;
• Sensing requirement of load and battery and providing supply, to drive load and battery, thereof;
• Providing a system and method for enabling dynamic correlation between the various charging modes [a) MPPT mode; b) CV mode; c) CC mode; d) Float mode] so that the system and method may enable the correct charging mode in order to drive the load and / or charge the battery.
While this detailed description has disclosed certain specific embodiments of the present invention for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

We claim,
1. A multistage load demand-dependant adaptive power management
system for charging battery comprising:
a. at least a battery sensor adapted to sense battery condition;
b. at least a loads' sensor adapted to sense load condition;
c. at least a first voltage defining means adapted to define a first pre-defined
voltage value in order to invoke a first function of charging in order to
start charging the battery;
d. at least a second voltage defining means adapted to define a second pre
defined voltage value in order to invoke a second function of charging in
order to continue charging of the battery;
e. at least a first current defining means adapted to define a first pre-defined
current value in order to invoke a third function of charging in order to
continue charging of the battery as well as to drive the load / mains;
f. at least a third voltage defining means adapted to define a third pre
defined voltage value in order to invoke a fourth function of charging and
also the second function with very less current; and
g. at least a determination mechanism adapted to determine a state of mode
of operation of the system and method depending upon sensed load
condition and sensed battery condition in correlation with first pre
defined voltage, second pre-defined voltage, third pre-defined voltage,
and fourth pre-defmed voltage, characterized, in that, said state of mode
of operation is at least a mode selectable from a group of modes
consisting of at least a Maximum Power Point Tracking mode, at least a
Constant Voltage mode, at least a Constant Current mode, and at least a
Float mode.
2. The multistage load demand-dependant adaptive power management
system for charging battery as claimed in claim 1, wherein said first pre-

defined voltage value is a pre-defined lower limit voltage of a battery which qualifies the battery as a deeply discharged battery.
3. The multistage load demand-dependant adaptive power management system for charging battery as claimed in claim 1, wherein said first function is a Maximum Power Point Tracking function.
4. The multistage load demand-dependant adaptive power management system for charging battery as claimed in claim 1, wherein said second pre-defined voltage value is an upper limit which is greater than the first pre-defined voltage value limit but lesser than a final pre-defined maximum terminal voltage value limit.
5. The multistage load demand-dependant adaptive power management system for charging battery as claimed in claim 1, wherein said second function is a Constant Voltage function.
6. The multistage load demand-dependant adaptive power management system for charging battery as claimed in claim 1, wherein said first predefined current value is a lower limit.
7. The multistage load demand-dependant adaptive power management system for charging battery as claimed in claim 1, wherein said third function is a Constant Current function.
8. The multistage load demand-dependant adaptive power management system for charging battery as claimed in claim 1, wherein said third predefined voltage is a pre-defined final (maximum terminal) voltage limit.

9. The multistage load demand-dependant adaptive power management system for charging battery as claimed in claim 1, wherein said fourth function is a Float Mode function.
10. The multistage load demand-dependant adaptive power management system for charging battery as claimed in claim 1, wherein said second pre-defined voltage being at least 80% of battery charge.
11. The multistage load demand-dependant adaptive power management system for charging battery as claimed in claim 1, wherein said system comprising a Maximum Power Point Tracking mechanism adapted to operate said system in said Maximum Power Point Tracking mode, characterised, in that, said battery being charged with maximum power when said sensed battery condition is at or below said first pre-defined voltage until said sensed battery condition reaches said second predefined voltage.
12. The multistage load demand-dependant adaptive power management system for charging battery as claimed in claim 1, wherein said system comprising a Constant Current mechanism adapted to operate said system in Constant Current mode, characterised, in that, said battery breaching said first pre-defined current value until said battery condition reaches said third pre-defined voltage value.
13. The multistage load demand-dependant adaptive power management system for charging battery as claimed in claim 1, wherein said system comprising a Constant Voltage mechanism adapted to operate the system in Constant Voltage mode, characterised, in that, said battery being maintained at said third pre-defined voltage value.

14. The multistage load demand-dependant adaptive power management system for charging battery as claimed in claim 1, wherein said system comprising a Float mechanism adapted to operate said system in Float mode, characterised, in that, said battery being almost charged and state of charge of batteries is well beyond the second pre-defined voltage.
15. The multistage load demand-dependant adaptive power management system for charging battery as claimed in claim 1, wherein said system comprising at least an insulation sensor adapted to sense insulation variation.