FIELD OF INVENTION
This invention directed to interactive solar educational and experimental kit. This invention relates to an improved solar educational kit that can be used as a tool for exploring, understanding and performing practical experimentation on the solar energy, and the means with which we can utilize it with the help of a hand on experiment kit and interactive software integrated with system.
PRIOR ART
Some educational models are known in the art, which are as follows: U.S. Pat. No 6,589,683 entitled " Regenerative fuel cell learning kit" is an Educational kit, which combines a unitized regenerative fuel cell with a demonstration platform to illustrate the principals of fuel cell use and application.
U.S. Pat. No. 5,154,615 entitled "The Educational Toy" is targeted toward older users. With motors, lights, wires, gears, and switches, it resembles a small laboratory a user can explore.
U.S. Pat. No. 6,135,776 entitled "Hands-on kit interactive software learning system" teaches users about a seed growing kit with which the user experiences plant germination, anatomy, photosynthesis, and other relating educational concepts firsthand. The kit provides for thorough hands-on interaction with the subject.
U.S. Pat. No. 6339538 entitled "Inverter circuit and method of operation" relates to photovoltaic (PV) power systems which utilize an inverter to convert the direct current (DC) output of PV arrays to alternating current (AC) and more particularly to improved methods and apparatus for measuring important system performance characteristics.
In each of these examples, the user interacts with the model and receives feedback from his or her work. Media comprises of educational tools that provide content in written, analog, or digital form. Books, videos, and encyclopedias are examples of media products. Computers provide alternative paths to the information in books and encyclopedias. Textbooks and other reference materials presented in electronic format have some benefits over hardbound material. Electronic content is more suitable for searching topics. Electronic presentation can also be enriched with video and audio. Whether electronic or hard copy, the underlying educational tool is the same, namely, a channel that provides bulk information.
The advantages of media are information availability and control. With media, a great deal of information can be made available to the user. Also, the learner can dictate the pace of learning. However, user interaction with the content in media education tools is passive. Electronic media may succeed in capturing the learner's attention by using creative ways of moving and advancing through the content, but the result is not
necessarily a deeper level of learning. Navigating through software is not a substitute for actively exploring a subject and then flipping the pages of a book. The disadvantage is that flat content is not like a model that encourages the user to probe and experiment with some real life situation.
Therefore, it would be highly desirable to have a new learning system that, like media, allows for user safety and large quantities of information, but also provides significant user interaction and feedback.
Some more educational tools are available in the art, which are listed herein below:
U.S. Pat. No. 5,577,185 entitled "Computerized Puzzle Gaming Method and Apparatus"
is a game created on a computer, which uses physical laws like gravity and motion. The
game is created and played on a computer.
U.S. Pat. No. 5,643,085 entitled "Two-Dimensional Cyclic Game for Creating and Implementing Puzzles" creates puzzles for the user to play with on the computer.
U.S. Pat. No. 5,088,928 entitled "Educational Board Game/Apparatus" is a board game connected to a computer. The user interacts with the board game together with the computer.
These games put the user in control. U.S. Pat. No. 5,088,928 allows for active user involvement since the environment includes a game board along with the computer but U.S. Pat. Nos. 5,643,085 and 5,577,185 do not provide that.
However, being merely computer games, the quantity of educational information
available to the user is limited.
Therefore, it would be highly desirable to create a new learning system that has the capabilities of computerized games, namely, user control and active user interaction and which also provides educational information.
Further, media in electronic form has advanced beyond simple electronic reference materials. Educational software developers have incorporated aspects of games into their work. The influence is obvious just from the titles of some commercial math teaching software: Math Munchers TM, NFL Math, The Great Math Adventure, and The Mighty Math Carnival Countdown. These programs place the user in control to access a lot of information. The programs also provide interaction within a virtual laboratory-type learning environment.
However, the interaction is limited to the computer screen where the virtual laboratory is displayed. Having no interactions outside the computer environment limits user involvement with the subject. These tools are also discretionary. The user has to possess
self-discipline to continue coming back to them. The game aspect is therefore necessary to elevate the level of interaction and feedback between the software tool and the user.
Therefore it would be highly desirable to have an improved learning system that provides the information content and user control of software and which also offers interaction beyond the computer.
Another patent known in the art is U.S. Pat. No. 5,360,344 entitled "Hands-On Learning System Including a Three-Dimensional Action Model Kit". The invention is based on a model building exercise similar in principle to Legos.RTM, but with educational emphasis. The three-dimensional action model provides the interaction component. The invention also has tools such as video players and computers in the learning environment to deliver information and complement the model.
However, this learning system requires the immediate presence of an expert or instructor to be substantially effective. The user, for example, could put together the model without having to work with the educational information. Conversely, the user could also step through the educational material without putting together the model. The learning system loses its effectiveness under these conditions because either the user misses learning from the information or the user loses the interactions with the model. The invention places the appropriate components in the environment but neglects to integrate the pieces to create a complete learning environment. As a result, an expert is required to work with the user in this learning system to provide feedback and help link the model and media, thereby not allowing the user to short circuit the overall learning process. Finally, this patent is not routinely interactive, that is the user has no incentive to return to it on a regular and routine basis.
Experts maintain control of the learning environment. Models do not provide the user with abundant information. Interaction is passive when media is used alone as a learning tool. Educational information is not conveyed to the users of computer-enabled games. Computer software is similar to hard-copy media in that interaction with the subject is limited.
Therefore it would be highly desirable to create an optimal learning system where there is not only educational media and models but also a means for integrating the media and models thus providing an interactive environment where the pace is still controlled by the user.
OBJECTS OF THE INVENTION
The principal object of the present invention is to provide a new and improved learning system using a hands-on kit along with a software tool that delivers information and works alongside the kit.
Another object of the present invention is to customize the software program with not only educational information but also with information that renders the kit and electronic media inseparable such that the user is required to interact with both.
Another object of the present invention is to develop a kit with additional features such as programmable bell, automatic lighting control, which can also serve the purpose of security.
It is a further object of the present invention to provide a solar educational kit which does not get affected by the direction of the sun and which can measure the PV module characteristics at different wavelengths.
STATEMENT OF INVENTION
According to this invention there is provided interactive solar educational and experimental kit comprising of PV modules connected to experimental module and solar charge controller along with inverter wherein the experimental module is interfaced with a computer installed with special software and database.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings and wherein:
Fig. 1 shows: illustrates a schematic overview of the solar educational kit with interactive
software system according to the present invention;
Fig. 2 A. shows a perspective view of inverter;
Fig. 2B shows a perspective view of the PV panels with filters;
Fig. 2B(i) shows a perspective view of the PV panels with motorized control;
Fig. 2C shows a perspective view of experimental module;
Fig. 2C (i) shows a circuit diagram for current sensing in experimental module;
Fig. 2C(ii) shows circuit diagram for voltage sensing in experimental module;
Fig. 2C(iii) shows a circuit diagram for PV1 sensing in experimental module;
Fig. 2C(iv) shows circuit diagram for PV2 sensing in experimental module;
Fig. 2C(v) shows circuit diagram for connection sensing in experimental module;
Fig. 2D shows a perspective view of solar charge controller;
Fig. 3 shows a top view of the CD-ROM;
Fig. 4 shows a perspective view of the computer;
Fig. 5 illustrates the main software interface screen;
FIG. 6 illustrates the user response file information flow;
FIG. 7 illustrates the composition of the content database;
FIG. 8A shows a flow chart outlining the typical user interactions with the interactive
software and solar educational kit, according to the present invention;
FIG. 8B shows a continuation of FIG. 8 A;
FIG. 8C shows a continuation of FIG. 8B;
FIG. 9 shows a flow chart of maximum power point tracking algorithm;
FIG. 10A, 10B shows a graph showing current versus voltage for a typical photovoltaic
solar system;
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS;
Reference may be made to fig. 1 wherein the user interacts with a kit and database content and user response file in a computer being at the center of activities.
The kit comprising of an inverter, PV panels, experimental module, solar charge controller and a battery connected to each other as shown in the figure l.The experimental module is interfaced through the communication port to the software installed on a computer.
The user completes the activities using the kit, and making observations. The user receives kit activity guidance and related educational information from the database content through the software program on computer. The user inputs his or her findings and thoughts in the database through user response file. The kit and the database content are oriented towards teaching about solar energy and its applications.
The inverter (FIG 2A) is to provide the supply when grid power is not available. Basic inverter design comprises of a controlling device, switching devices, battery and transformer. DC supply from battery is connected to a transformer through the centre tap of the primary winding. The microcontroller controls switching scheme and the duty cycle of switching devices to produce alternation of the direction of current in the primary winding of the transformer and to produce alternating voltage in the secondary circuit.
The PV panels (FIG 2B) are of for example 150-150 Watts but optionally smaller or higher wattage panels can also be used. The output of PV module is connected to the DC-to-DC buck converter on charge controller but during the experiments the PV panels are connected to the experimental module. There are filters provided, which can be positioned over the PV modules. They pass only specific wavelengths to the panels and
with the help of these filters PV characteristic graph for the different wavelengths can be drawn to understand the effect of variation in wavelength of light on the panel
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characteristics and maximum power point. The PV panels are fitted on the motorized platform (FIG 2B(i)), which tracks the sun during daytime so that the panels are always oriented towards sun and maximum power can be drawn from the system.
Optionally smaller modules can also be used with the kit for indoor experiment or when the sun is not available. In this case bulbs can be used to illuminate the PV modules, which works as a simulator for actual PV power. This way the experiments can be performed even when sun is not available.
The experimental module in FIG 2C comprises of a control board, which contains different sections such as supply section, experiment terminals section, external sensors interfacing circuit, PV panel detection section along with microcontroller section. The PV modules are connected to the experimental module through the terminals provided. By varying the external load connected at the experimental terminals the PV current versus PV voltage graph can be drawn for different configuration of PV modules. This experimental module can be interfaced with PC through serial port and PV voltage, PV current and PV power can be observed on the graphical user interface. The PV voltage and current are sensed through sensing circuits. The voltage is measured through the voltage divider circuit as shown in FIG 2C(ii). The current is measured with the help of shunt resistance, voltage across the shunt is proportional to the current flowing through it, this voltage signal is given to an operational amplifier integrator circuit, the output of which is connected to microcontrollers ADC channel as shown in FIG 2C(i). There are voltage-sensing circuits, which automatically sense the PV panels and the series and parallel combination of PV panels. In FIG 2C(iii) and FIG 2C(iv) circuits show how the PV voltage from two panels is sensed through optocouplers. The circuit shown in FIG 2C(v) shows how the panel connection combinations are sensed to detect the connection. There is a LDR sensor included which senses the light to control the lighting through programmable settings. An alarm bell with programmable timer and smoke/fire alarm is also attached to the module. These settings can be programmed with the help of software. LCD provided on the experimental module displays value of all the system parameters, information about system status and other useful information for user.
The digital signal controller on the charge controller regulates the duty cycle of the switching devices based on the feedback sense of PV voltages, PV current, battery voltage and battery current. The controller implements the maximum power point tracking algorithm to operate the PV module close to the maximum power point voltage so that at any given time maximum possible power can be extracted from the modules.
The controller also regulates charging of the battery connected at the output of DC-DC converter. It implements the three stage charging strategy to prevent any overcharging. The controller also takes care of temperature compensation for control of charging. The heat sink temperature is also monitored to prevent any fault condition. The controller also provides serial communication for monitoring and data logging of various parameters on computer.
Battery is a lead acid battery, which gets charged from PV panel through solar charge controller.
A CD-ROM depicted in FIG. 3 holds the database content and a software program that directs the project. The database content complements the kit activities. Alternatively, the database content can be distributed by other low-cost means, for example magnetic media or Internet. The preferred embodiment of the present invention is to distribute the software program and content database via CD-ROM.
The graphical user interface to the software program is shown in FIG. 5, which is a control panel. This interface shows various system parameters such as PV voltage and current along with PV power. It also incorporates an interactive animation film, which familiarizes the users with basics of solar energy, and how it can be used in our homes and what is the significance of solar energy in future. It has also links to many documents, which the user can read. This software also includes a quiz program about solar energy to test the knowledge of users. The user can attempt the questions and_see the results at the end of all questions.
FIG. 6 indicates how content flows to and from the content database. The database delivers information related to the current topic. The list of glossary terms provides definitions of terms related to the current activities. The content database provides content to each of the interfaces with the relevant facts. That is, content for each of the interfaces is stored in and accessed from the content database. The database is a read-write access file. It contains all user input. That information is stored in and later retrieved from the database. The user can view and print information entered in the journal from the report. The information for the report is also stored in and later retrieved from the database.
In the present invention, the database is stored on the hard-drive of the computer. Alternatively, the information can be stored on any read-write magnetic or optical medium.
The content database is read-only and contains multimedia content that is displayed at runtime. The types of content in the content database are depicted as a block diagram in FIG 7. They are illustrations, sounds, photographs, and animation. As described in the discussion of FIG. 6, the content database provides information to the user, the facts, and the glossary. Contents are held in individual files.
FIGS. 8A, 8B and 8C outline the flow of the software program pertaining to the operation of the invention. Each visit to the software by the user 20 triggers a series of activities that the user 20 steps through as shown in FIGS. 8A, 8B and 8C.
When the user starts the program it prompts the user to enter the name and identity. After that the program prompts the user to select the serial port on the pc to communicate with the experimental module. Once the communication is set up it is ready to run. Now user is provided with a number of options available such as he can participate in the quiz program or he can start the solar animation film to learn about solar energy, he can also see a number of documents that give information about various aspects related to the solar energy. The user can also perform a number of practical experiments on PV modules. The user can draw graphs between PV current and PV voltage with various configurations of PV modules to understand their relationship and the maximum power point of the PV modules. When the user enters the quiz area the software displays different questions related to solar energy with four possible answers. The user then enters his response and software takes the user response and gives correct answer for that question. After all questions are attempted, the software shows the result with user name, which are also saved in the database with user name, and identity code.
When a user enters the animation film section he can browse through different animated slides that give information about solar energy and its uses. The software displays important information and description of major components shown in the animation when the user selects them. The user can see a number of documents related to solar energy through the links provided in the animation film
FIG 9 outlines the flow chart of maximum power tracking algorithm. The MPPT algorithm constantly regulates the converter duty cycle based on the PV current and voltage sense signals. The controller reads the analog to digital converter outputs corresponding to PV current and voltage and filter it to reject any noise. Then with the help of current and voltage signals the power is calculated. If the power obtained from the current samples is greater than the previous samples than the duty cycle is corrected with change in the same direction as in case of previous sample else the sign of the correction is inverted and the converter duty cycle is updated. In case of no change in the power the duty is not changed and next sample is taken for comparison.
FIG 10A and 10B shows a useful data set of current and voltage. This set of points is called a current voltage trace or I V curve. FIG10B shows the power verses voltage characteristic for a panel. It is useful in understanding and calculation of maximum power point for a PV module.
When the user indicates that, he or she wants to view the report, the program accesses the database and retrieves user input from all visits by the same user. It then formats the information and displays the report. Any changes the user makes to the report are stored in the user response file. If the user requests a printout, the program sends the report for printing.
It should be understood, however, that even though these numerous characteristics and advantages of the invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of kit type, educational content, and software architecture within the scope of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
The program also consists of several interfaces that the user interacts with. One interface holds entertaining and scientific facts; another holds a readily accessible glossary of scientific terms. There is also an interface that functions as a laboratory journal for users input of observations and measurements. These data are recorded and tracked by the user. At the completion of the project, the software compiles the user's information into an accessible final report for reading and printing. The report is the end product representing the learning achieved during the course of the project. The report is the reward for the work the user accomplishes. The user can continue to explore more information within the software after the completion of the project.
The present invention also has feature to switch on/off the lights. The kit also provides a programmable electric bell, smoke detector and fire alarm for the safety.
In the present embodiment, the target user is 12 to 17 years old. However, other embodiments of the invention could be aimed at older or younger audiences simply by tailoring the software or the kit or both to fit the age or experience level of the contemplated users.
It is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims:-

WE CLAIM:
1. Interactive solar educational and experimental kit comprising of: PV modules
connected to experimental module and solar charge controller along with
inverter wherein the experimental module is interfaced with a computer
installed with special software and database.
2. Interactive solar educational and experimental kit as claimed in claim 1
wherein output of the PV modules is connected to DC-DC buck converter on
the charge controller and during the experiment, the PV panels are connected
to the experimental module.
3. Interactive solar educational and experimental kit as claimed in claim 1 or 2
wherein the experimental module comprises of a control board having a
plurality of sections such as supply section, experiment terminals section,
external sensors interfacing circuit, PV panel detection section, along with
micro controller section.
4. Interactive solar educational and experimental kit as claimed in any of the
preceding claims wherein the module comprising of current sensor circuit,
voltage sense circuit, PV sense circuits and PV Module connection sense
circuit.
5. Interactive solar educational and experimental kit as claimed in claim 4
wherein the module comprising of an alarm bell with programmable timer and
smoke/fire alarm.
6. Interactive solar educational and experimental kit as claimed in claim 5
wherein the experimental module displays value of all the system parameters,
information about system status and other useful information for user.
7. Interactive solar educational and experimental kit as claimed in any of the
preceding claims comprising of graphical user interface, which shows various
system parameters such as PV voltage and current alongwith PV power and
incorporates an interactive animation film.
8. Interactive solar educational and experimental kit substantially as herein
described with reference to the accompanying drawings.