MULTI SOURCE ENERGY OPTIMIZER
BACKGROUND OF THE INVENTION
Field of Invention
The field of the present invention relates to the simultaneous use of multiple energy sources.
Description of the Problem
It is increasingly being recognized that renewable energy sources (such as electricity generated using the sun or wind) are preferable to conventional energy sources (such as electricity generated using coal or oil). Non-renewable energy sources are, amongst other things environmentally unfriendly.
Renewable energy sources however suffer from the drawback that they tend to be unreliable particularly in the short run. A solar photovoltaic cell will generate varying energy depending on solar irradiation and only a fraction of its power in case a cloud/ other object interpose itself, even if briefly between the sun and the cell. Wind speed tends to fluctuate and the output from windmills fluctuates correspondingly.
The requirement for power particularly in the short run however is likely to be independent of the sources ability to supply power. In case the renewable energy source(s) are unable to supply the required power it would become necessary to provide power using conventional energy sources for the remaining energy requirement.
In order to maximize use of renewable energy sources it is however necessary that the maximum power available from such sources is first utilized and thereafter power from conventional sources used to make good the shortfall in availability.
There is thus a need for an apparatus that optimizes the use of renewable energy.
Energy Curves for Solar and Wind Energy Sources
The energy output versus current graph for different sun intensities is described in Fig. 1 for a particular photovoltaic cell. The graph of Fig. 1, while following the general shape, will vary depending on the construction of a particular photovoltaic cell. It would

be noted from Fig. 1 that for particular sun intensity, a photovoltaic cell will produce maximum power at a particular current.
Similarly, the energy output versus current graph for different wind speeds is described in Fig. 2 for a particular windmill. The graph of Fig. 2, while following the general shape, will vary depending on the construction of a particular windmill. It would be noted from Fig. 2 that for a particular wind speed, a windmill will produce maximum power at a particular current.
SUMMARY OF THE INVENTION
The invention of this Application discloses an apparatus for optimizing the use of renewable energy sources without disturbing the power required for particular loads or applications.
The invention of this Application will be described by means of embodiments. It will be noted that the embodiments are given only by way of example and are not meant to limit in any way the generality of the invention. The invention, as would be evident to a person skilled in the arts can be embodied in many other ways.
BRIEF DESCRIPTION OF THE DRAWING
Fig. 1 describes the power versus current graph for different sun intensities for a particular construction of a photovoltaic cell.
Fig. 2 describes the power versus current graph for different wind speeds for a particular construction of a windmill.
Fig. 3 describes an embodiment of the invention of this Application whereby the block schematic of the operation with solar and wind power sources is shown.
Fig. 4 describes an embodiment of the invention of this Application whereby the block schematic of the operation with solar and wind power sources along with Mains source is shown.
Fig. 5 describes an embodiment of the invention of this Application whereby the block schematic of the operation with solar and wind power sources along with Mains source and Diesel Generator Set (DG) is shown.

e) a Microcontroller 2 comprising:
a. a PWM Controller (not shown);
b. a data storage device (not shown);
f) a Load 4;
In the apparatus of the invention either the photovoltaic cell or windmill is first selected and the Microcontroller 2 is used to measure the output power of the selected device. Each measurement is compared with the previous measurement (in case of the very first measurement the measurement is just noted).
In case the subsequent measurement is more than the previous measurement the power set point is changed to the higher value. If the subsequent measurement is lower than previous value the power set point is retained at the earlier value. The process is repeated until the maximum power point is reached. The maximum point is then held at peak in dynamic state the incrementing process never stops.
In case the power output by the selected source is less than the power required by the Load 4 or the application, the power output by the second renewable source is then measured and the power output sequentially increased till either:
(a) the power required by the Load 4 or application is available; or
(b) the maximum power point is reached.
Measurements as above can be taken after any predetermined time intervals:
(a) preferably between 10 to 15 seconds in the case of solar power; and
(b) preferably between 3 to 5 seconds in the case of wind power.
In case the power made available by the one renewable energy source is less than the power required by the Load 4, the remaining power can be made available from the other renewable power source.
This embodiment can be implemented also with analog circuits, instead of using a microcontroller as would be evident to a person skilled in the art. The term "Microcontroller" thus refers to either a microcontroller or an analog circuit.

Fig. 6 describes an embodiment of the invention of this Application whereby the block schematic of the operation with solar and wind power along with Mains, DG and Inverter is shown.
Fig. 7 describes an embodiment of the invention of this Application whereby the block schematic of the operation with solar and wind power along with Mains, DG, telecom rectifier, Inverter and battery in float mode is shown for telecom application.
DETAILED DESCRIPTION
This invention will further be described with reference to the embodiments hereinafter provided. The embodiments are by way of example only and are the invention can be embodied in many different ways as would be evident to a person skilled in the art.
The embodiments below are described with reference to one or more renewable energy sources (referred to as "energy sources") and optionally power from the Mains, DG or Inverter.
It would however be noted that the invention is general in nature and independent of individual energy sources except to the extent specifically indicated. The invention can be adapted to work with any plurality of energy sources.
EMBODIMENTS
EMBODIMENT 1
The first embodiment of this invention as described in Figure 3 comprises:
a) a Solar energy sources 1 comprising:
a. multiple photovoltaic cells (not shown);
b) a Wind energy sources 21 comprising:
a. multiple windmills (not shown);
c) a Converter 3 comprising:
a. DC to DC Converter or DC to AC Converter or AC to DC Converter in case of windmills;
d) one or more rectifiers 301 for converting AC power from the windmills;

It would be noted that while it is stated above (and in subsequent embodiments) that the power set point is retained at the maximum power point, it would be evident to the person skilled in the art that the power set point is so retained only if the Load 4 requires such power. In case the Load 4 requires lesser power, the power set point would be accordingly adjusted.
EMBODIMENT 2
Fig. 4 describes another embodiment of the invention of this Application comprises:
a) a Solar and Wind energy source 11 (not separately shown) of the type described in the previous embodiment. A rectifier would also be electrically coupled to the windmills as in the previous embodiment;
b) a conventional power source such as coal generated power available at Mains 5;
c) a Converter 3 comprising:
a. DC to DC Converter or DC to AC Converter or AC to DC Converter in case of windmills;
d) a Microcontroller 2 comprising:
a. a PWM Controller (not shown);
b. a data storage device (not shown);
e) a Load 4.
In the apparatus of the invention maximum power is drawn from the renewable sources as described in the previous embodiment.
In case despite the maximum power point for the second renewable source being reached, the power made available by the renewable energy sources is less than the power required by the Load 4; the remaining power can be made available from the mains power source.

EMBODIMENT 3
In many areas of the world particularly in developing countries, mains power is unreliable. There is in such situations, when the application or Load must be supplied with the required power, need for a standby source of power such as Diesel Generating Set (DG). The DG can be used in case the renewable sources are unable to supply the power required by the application or Load and mains power is unavailable.
Fig. 5 describes another embodiment of the invention of this Application comprising:
a) a Solar and Wind energy source 11 (not separately shown) of the type described in the previous embodiment;
b) a conventional power source such as coal generated power available at the Mains 2;
c) aDG6;
d) a Converter 3 comprising:
a. DC to DC Converter or DC to AC Converter or AC to DC Converter in case of windmills;
e) a Microcontroller 2 comprising:
a. a PWM Controller (not shown);
b. a data storage device (not shown);
f) a Load 4.
As in the previous embodiment first power generated by renewable sources 11 is first utilized. In case, the power generated by these sources is not sufficient to meet the requirement of the application or Load 4, power from the Mains 5 is first used to make good the shortfall and in case mains power is not available the required power is taken by starting the DG 6.

EMBODIMENT 4
In the case of loads wherein power outage is impermissible even for the short period of time needed to start the DG it is necessary to have provision for an Inverter (which includes "uninterrupted power supply (UPS)"). Such systems are often required for applications such as power supply for computers, power supply to operation theatres and other mission critical applications.
Fig. 6 describes another embodiment of the invention of this Application comprises:
a) a Solar and Wind energy source 11 (not separately shown) of the type described in the previous embodiment;
b) a conventional power source such as coal generated power available at the Mains 5;
c) aDG6;
d) an Inverter 7;
e) a Converter 3 comprising:
a. DC to DC Converter or DC to AC Converter or AC to DC Converter in case of windmills;
f) a Microcontroller 2 comprising:
a. a PWM Controller (not shown);
b. a data storage device (not shown);
g) a Load 4.
As in the previous embodiment first power generated by renewable sources is first utilized. In case the power generated by these sources is not sufficient to meet the requirement of the application or Load 4, power from the Mains 5 is first used to make good the shortfall and in case mains power is not available the required power is taken from the Inverter 7.
Depending on the battery capacity of the Inverter 7 when power is taken from it, a decision is taken to start the DG 6 or to await mains power. Such decision making is

facilitated by keeping record of the duration and frequency of Mains 5 failure. In case it is anticipated that mains power will be available during the time that the Inverter 7 can supply power, the DG 6 will not be switched on till the ampere hour value of the Inverter batteries falls below a predetermined value. Once the ampere hour value of the Inverter batteries falls below the predetermined value the DG 6 will be switched on. The DG 6 may be used to supply power to just the application or Load 4 or to also recharge the Inverter batteries depending on the expectation of:
(a) the time at which mains power will be available;
(b) the time at which the power from the renewable energy sources will be greater than the power required by the application or Load 4 and the excess power can be used to charge batteries;
(c) the Load 4 at which the DG 6 operates optimally.
EMBODIMENT 5
A special class of mission critical applications of the previous embodiment relates to the power requirement of telecom sites.
Telecom sites for most of their requirement need DC power at 48 volts.
For their DC power needs, telecom sites, in addition to using Inverters as in the previous embodiment, keep batteries in float mode.
Fig. 7 describes another embodiment of the invention of this Application comprising:
a) a Solar and Wind energy source 11 (not separately shown) of the type described in the previous embodiment;
b) a conventional power source such as coal generated power available at the Mains 5;
c) aDG6;
d) an Inverter 7;
e) a telecom rectifier 8 for high quality power rectification;

f) a Microcontroller 2 comprising:
a. a PWM Controller (not shown);
b. a data storage device (not shown);
g) a telecom load 9.
As in the previous embodiment first power generated by renewable sources is first utilized. In case the power generated by these sources is not sufficient to meet the requirement of the application or Load 4, power from the Mains 5 is first used to make good the shortfall and in case mains power is not available the required power is taken from the DG 6 in case the ampere hour value of the batteries in float mode is below a predetermined value as in the previous embodiment The decision whether to use the DG 6 to charge the Inverter 7 is taken on the same consideration as in the previous embodiment.
In this embodiment in addition to measuring the ampere-hour capacity of the batteries in float mode the temperature of the telecom site is also measured. In case the temperature crosses a predetermined value the DG 6 is started (in case mains power is not available) and the DG 6 used to also supply power to the application or Load 4 and/or to charge the float batteries depending on the expectation of:
(a) the time at which mains power will be available;
(b) the time at which the power from the renewable energy sources 11 will be greater than the power required by the application or Load 4 and the excess power can be used to charge batteries;
(c) the Load 4 at which the DG 6 operates optimally.

I/We Claim
1. An apparatus adapted to work with a plurality of energy sources and a Load 4
comprising:
a) a Converter 3;
b) a Microcontroller 2 is adapted to:
i. select an energy source, periodically measure the output power of the selected energy source and compare each measurement with the previous measurement;
ii. sense the power required by the Load 4;
such that:
the Microcontroller 2 first selects an energy source and maintains the output power of such first energy source at maximum power point;
Microcontroller 2 senses the power required by the Load 4 and in case the output power of the first selected energy source is less than the power required by the Load 4, the Microcontroller 2 selects a second energy source and maintains the output power of such second energy source either at level required by the Load 4 or at maximum.
2. The apparatus of claim 1 wherein the energy sources are solar energy source 1 and wind energy source 21.
3. The apparatus of claim 1 wherein the Converter 3 comprises a DC to DC Converter or DC to AC Converter or AC to DC Converter.
4. The apparatus of claim 2 wherein the Converter 3 comprises an AC to DC Converter.
5. The apparatus of claim 2 further comprising one or more rectifiers 301.
6. An apparatus adapted to work with a plurality of energy sources 11, Mains 5 and a Load 4 comprising:
a) a Converter 3;
b) a Microcontroller 2 is adapted to:
i. select an energy source, periodically measure the output power of the selected energy source and compare each measurement with the previous measurement;
ii. sense the Mains 5;
iii. sense the power required by the Load 4;
such that:
the Microcontroller 2 first selects an energy source and maintains the output power of such first energy source at maximum power point;
Microcontroller 2 senses the power required by the Load 4 and in case the output power of the first selected energy source is less than the power required by the Load 4, the Microcontroller 2 selects a second energy source and maintains the output power of such second energy source either at level required by the Load 4 or at maximum;
In case the Load 4 requires further power, the further power is made available from the Mains 5.
7. The apparatus of claim 6 wherein the energy sources are solar energy source and wind energy source.
8. The apparatus of claim 6 wherein the Converter 3 comprises a DC to DC Converter or DC to AC Converter or AC to DC Converter.
9. The apparatus of claim 7 wherein the Converter 3 comprises an AC to DC Converter.
10. The apparatus of claim 7 further comprising one or more rectifiers 301.
11. An apparatus adapted to work with a plurality of energy sources 11, Mains 5,
DG 6 and a Load 4 comprising:
a) a Converter 3;
b) a Microcontroller 2 is adapted to:
i. select an energy source, periodically measure the output power of the selected energy source and compare each measurement with the previous measurement;
ii. sense the Mains 5;
iii. sense the DG 6;
iv. sense the power required by the Load 4;
such that:
the Microcontroller 2 first selects an energy source and maintains the output power of such first energy source at maximum power point;
Microcontroller 2 senses the power required by the Load 4 and in case the output power of the first selected energy source is less than the power required by the Load 4, the Microcontroller 2 selects a second energy source and maintains the output power of such second energy source either at level required by the Load 4 or at maximum;
In case the Load 4 requires further power, the further power is made available from the Mains 5 or in case a power is unavailable from the Mains 5, further power is made available from the DG 6.
12. The apparatus of claim 11 wherein the energy sources are solar energy source and wind energy source.
13. The apparatus of claim 11 wherein the Converter 3 comprises a DC to DC Converter or DC to AC Converter or AC to DC Converter.
14. The apparatus of claim 12 wherein the Converter 3 comprises an AC to DC Converter.
15. The apparatus of claim 12 further comprising one or more rectifiers 301.
16. An apparatus adapted to work with a plurality of energy sources 11, Mains 5, DG 6, Inverter 7 and a Load 4 comprising:
a) a Converter 3;
b) a Microcontroller 2 is adapted to:
i. select an energy source, periodically measure the output power of the selected energy source and compare each measurement with the previous measurement;
ii. sense the Mains 5;
iii. sense the Inverter 7 and ampere hour value of batteries coupled to the Inverter 7;
iv. sense the DG 6;
v. sense the power required by the Load 4;
such that:
the Microcontroller 2 first selects an energy source and maintains the output power of such first energy source at maximum power point;
Microcontroller 2 senses the power required by the Load 4 and in case the output power of the first selected energy source is less than the power required by the Load 4, the Microcontroller 2 selects a second energy source and maintains the output power of such second energy source either at level required by the Load 4 or at maximum;
In case the Load 4 requires further power, the further power is made available from the Mains 5 or in case a power is unavailable from the Mains 5, further power is made available from the Inverter 7 or the DG 6.
17. The apparatus of claim 16 wherein the energy sources are solar energy source and wind energy source.
18. The apparatus of claim 16 wherein the Converter 3 comprises a DC to DC Converter or DC to AC Converter or AC to DC Converter.
19. The apparatus of claim 17 wherein the Converter 3 comprises an AC to DC Converter.
20. The apparatus of claim 17 further comprising one or more rectifiers 301.
21. The apparatus of claim 16 wherein the power is made available from the DG 6
when the ampere hour value of the batteries falls below a predetermined value.
22. The apparatus of claim 21 wherein the DG 6 is used to charge the batteries.
23. The apparatus of claim 16 wherein the Load 4 is a telecom load 9.
24.The apparatus of claim 23 further comprising telecom rectifier 8 and batteries in float mode.
25. The apparatus of claim 24 wherein the Microcontroller 2 can sense the batteries
in float mode.
26. The apparatus of claim 25 wherein the DG 6 is used to charge the batteries in
float mode if the ampere hour of such batteries falls below a predetermined
value.
27.The apparatus of claim 26 further comprising a data storage device.