Domestic Inverter with Renewable Battery

Abstract

This invention is representing the multimodal power source charging with a micro inverter. We are trying to use the maximum renewable energy to reduce the pollution and save energy. So, when the sunlight is available, we will run our house hold load on renewable energy source storage. At night only we use the AC source and we also keep a DC battery backup for failure of AC source at night or when there is not proper sunlight. This invention describes how to design a low cost 100 W dc to ac converter and combining multiple power sources to charge a battery, for photovoltaic power conversion in residential applications. We also included the battery charging circuit. The DC battery source will be charged by both DC 12V (Solar Panel) as well as AC 220V. We got 220V AC in the output of the inverter. The main motive of the invention is that the renewable energy will be used in the day time and the AC source will be used at the night in case of there is also a monitoring system which indicates the charging level of

Description

Field of the Invention

[001] Now a day's generation of electric energy is facing a lot of difficulties. The stock of nonrenewable energy sources is reducing day by day so the electricity cost is increases. But if we usethe renewable energy source the first cost of installation is large but overall cost will less and it isnot harmful in our environment and nature. The invention discusses the lowest powerconjunction from the source that is harming the environment. So, it is about using the renewablepower sources to protect the environment and the Earth from the global warming. The inventionshows only two power sources that are in use but it has also had the option to use multiplesources to use in single. For this it is more secure and safe for human in daily uses or storeenergy.Background of the invention and related prior Art

[002] Now-a-days generation of electric energy is faced a lot of difficulties. The stock of nonrenewable energy sources is reducing day by day and as a result the cost of electricity isincreasing. But if we use the renewable energy source the initial cost of installation is large butoverall cost will be reduced and it is not harmful for our environment and nature.The need of running AC Loads on solar energy leads us to the design of Solar Power Inverter.Since the maturity of ultramodern conveniences all run on 220 volts AC, the Power Inverter willbe the heart of the Solar Energy System. It not only converts the low voltage 12 volts DC to the220 volts AC that runs utmost appliances, but also can charge the batteries if connected to themileage grid as in the case of a completely independent stage-alone solar power system. Theseare special inverters which are designed to draw energy from a battery, manage the batterycharge via an on-board bowl, and import redundant energy to the mileage grid.The requirement for operating AC Loads using solar energy necessitates the creation of a SolarPower Inverter. The Power Inverter will be the core of the Solar Energy System, as the majorityof modern amenities run on 220 volts AC. It not only converts the low voltage 12volts DC to the220 volts AC that runs most appliances, but also can charge the batteries if connected to theutility grid as in the case of a totally independent stand-alone solar power system. These specialinverters are designed to draw energy from a battery, manage the battery charge through anonboard charger, and export any excess energy to the utility grid. The solar panels on our roofabsorb sunshine in the form of direct current (DC) power. Tucked beneath each panel, a microinverter converts that DC power to alternative current (AC), the form of electricity our home canuse. Inverters can be used to supply AC power from DC sources such as solar panels or batteries,thus providing an efficient solution.

[003] In a patent document US8482155B2 discloses a power converting device fora renewable energy storage system includes rechargeable batteries, bidirectional convertersrespectively connected in parallel to the batteries, direct current (DC) links connected in parallelto the bidirectional converters, respectively, bidirectional inverters connected in parallel to theDC links, respectively, and an electric power system connected to the bidirectional inverters.The bidirectional inverters are cascade H-bridge multi-level boost inverters. The DC links arecharged by the bidirectional inverters connected to the battery and a charged voltage of the DClinks is provided to the electric power system by the bidirectional inverters. In addition, the DClinks are charged by the bidirectional inverters connected to the electric power system and acharged voltage of the DC links is provided to the battery by the bidirectional inverters.

[004] Another patent document US5373195A discloses an ac electric drive system that includesa bidirectional power semiconductor interface between a battery, or an auxiliary energy storagedevice, and a power inverter for boosting an input dc voltage and for decoupling the dc linkvoltage from the input dc voltage such that the dc link voltage is substantially independent of theinput dc voltage and the parameters of the battery or energy storage device. The input dc voltageis controlled to maximize efficiency along predetermined torque envelopes.

[005] A document US6404655B1 discloses an improved transformer less 3-phasepower inverter topology and control method for power distribution systems. This 3-phasepower inverter system provides the necessary output voltage and current waveform regulation,harmonic distortion rejection, very low output impedance, and ultra-low DC offset of the outputAC power, even when exposed to a high magnitude of the non-linear, single phase, or theunbalanced loading.

[006] Another document US7248490B2 discloses multiple inverter / battery modules that areused in parallel but can be individually shut down in order to increase efficiencyof battery powered AC electricity supply. The number of inverters activated depends on thepower usage. When only a little power is needed only one or a few inverters are activated. Whenmore power is needed the battery inefficiency increases and more inverters will be activated.

[007] A patent document US20080067869A1 discloses a system for connecting a fuel cell stackto an A.C. grid to provide power in which a voltage regulated D.C. bus is provided to be coupledto the fuel cell stack, a bidirectional inverter is coupled to the D.C. bus, and is to be coupledbetween the D.C. bus and the A.C. grid. At least one D.C. auxiliary load of the fuel cell stack isprovided coupled to the D.C. bus. A D.C. to D.C. converter is provided between the fuel cellstack and the D.C. bus.

[008] None of these above patents, however alone or in combination, disclose the presentinvention. The invention consists of certain novel features and a combination of parts hereinafterfully described, illustrated in the accompanying drawings, and particularly pointed out in theappended claims, it being understood that various changes in the details may be made withoutdeparting from the spirit, or sacrificing any of the advantages of the present invention.Summary of the Invention:

[009] This invention is representing the multimodal power source charging with a micro inverter.We are trying to use the maximum renewable energy to reduce the pollution and save energy. So,when the sunlight is available, we will run our house hold load on renewable energy sourcestorage. At night only we use the AC source and we also keep a DC battery backup for failure ofAC source at night or when there is not proper sunlight. This invention describes how to design alow cost 100 W dc to ac converter and combining multiple power sources to charge a battery, forphotovoltaic power conversion in residential applications. We also included the battery chargingcircuit. The DC battery source will be charged by both DC 12V (Solar Panel) as well as AC220V. We got 220V AC in the output of the inverter. The main motive of the invention is thatthe renewable energy will be used in the day time and the AC source will be used at the night incase of there is also a monitoring system which indicates the charging level of the battery and theoutput voltage is 220 V or not. If output voltage is less than 220V then the inverter willautomatically turn off for.Detailed description of the invention with accompanying drawings:

[010] For the purpose of facilitating an understanding of the invention, there is illustrated in theaccompanying drawing a preferred embodiment thereof, from an inspection of which, whenconsidered in connection with the following description, the invention, its preparation, and manyof its advantages should be readily understood and appreciated.

[011] The principal object of the invention is to develop domestic inverter with renewablebattery. It has 3 phases i.e., switching from the solar to battery, AC source to the battery and thebattery to the inverter. The other additional part is the monitoring system, where we can monitorthe whole system and control as well.Modelling of Photovoltaic SystemThe ideal PV cell consists of a constant current source and a diode whereas the practical PV cellconsists of additional series Rs and parallel resistance Rp. The basic equation which describesthe I-V characteristic of an ideal PV cell can be represented as:Equation (1)Table 1. Parameters and its valuesWhere Ipv is the current of PV cell and Id is Shockley diode equation. Shockley diode equationcan be represented asEquation (2)Substituting Eq. (2) in Eq. (1), the modified I-V characteristics of an ideal PV cell can berepresented as: Equation (3)where Io is the leakage current of diode, q is the electron charge 1.6021 x 10-19 C, K is theBoltzmann constant 1.3805 x 10-23 J / K, T is the temperature of p-n junction (Kelvin), a is theideality constant of diode.Practical PV array comprises of series or parallel connected PV cell. The I-V characteristics ofpractical PV array can be represented as Equation(4)Here, Ipv is PV current and Io is saturation current. Rp is equivalent parallel resistance, Rs isequivalent series resistance and Vt is the thermal voltage of PV cell with Ns cells connected inseries connection. The thermal voltage of the PV cell can be represented asThe current of the PV cell is dependent on solar irradiance and temperature. The relationbetween the PV current and temperature can be represented asEquation (5)where is light generated current at nominal operating condition (25°C, 1000W / m2), is thedifference of temperature (Actual and nominal temperature), G is the irradiance of the surfaceand is the nominal irradiance The relationship of diode saturation current with temperaturecan be represented as Equation(6)Here, is the bandgap of semiconductor.Mathematical Model of Battery

[012] There are different types of rechargeable batteries available in the market and the lead-acidbattery is the oldest type of rechargeable battery. The lead-acid battery comprises two electrodesand the electrolyte. Lead Oxide (PbO2) serves as the Cathode, Lead (Pb) electrode severs as theanode and 33.5 % (V / V) sulphuric acid (H2SO4) serves as the electrolyte. The electro-chemicalreaction of the cathode and anode produces electric energy. The electro-chemical can berepresented byHere, (s) refers to the solidThe overall reaction during charging of a lead-acid battery can be represented asLead acid battery has a high specific power, so it can supply high surge current. Therefore, leadacid batteries are used in Electric and hybrid automobiles. The aging problem of lead acid batterycan be contributed to various factors such as anodic corrosion, loss of water, short circuit andaccumulation of lead sulphate. There are different types of lead acid batteries such as floodedbattery, valve regulated lead acid battery and absorbent glass mat battery. To quantitativelydescribe the behaviour of battery different parameters such as capacity, state of charge, depth ofcharge, state of health and internal resistance are used.Different mathematical model of battery has been described in literature. The generic model ofbattery presented in is implemented in this invention. This model considers state of charge(SOIC) as the state variable and can accurately represent electro-chemistry of the battery. Thegeneric model of the battery can be represented asHere, is no-load battery voltage (V); k is polarization voltage (V); Q is battery capacity (Ah); is charge drawn or supplied by the battery (Ah); A is exponential zone amplitude (V); B isexponential zone time constant inverse (Ah)-1; is battery voltage (V); R is internalresistance of battery (); is battery current (A).Relay System:We have used a 12V DC Relay to perform this task. Whenever the coil of the relay activates thebattery charging source will be switched. Here in our invention in the day time the coil of therelay will active so the battery will charge using it, and at the night the battery will charge usingthe AC source through the converter.Here the most important thing is that the battery will charge if the battery drains its maximumstored charge like 95%.Methodology

[013] Renewable energy can be the strong weapon to protect the Earth from the global warming,for this we propose this invention. In this invention we use multiple power sources to tear theenergy. We used a solar panel 18V 50W source, an AC source and a 12V 14 Ampere battery.Solar power switcher, the main working part for this circuit is to get output of a 14V DC 2.1Ampere to charge the battery Solar battery charger operated on the principle that the chargecontrol circuit will produce the constant voltage. The charging current passes to LM317 voltageregulator through the diode D1. The output voltage and current are regulated by adjusting theadjust pin of LM317 voltage regulator. Battery is charged using the same current.AC to DC converter, used for Converting the 220V 50Hz AC to 14V 2Ampere DC, Relay board,uses of this circuit is to Switch the charging source of the battery as required, as if the batterydrain the whole charge of itself then the relay circuit allow to charge the battery using the ACsource and other one circuit is in the output side (Battery out) i.e. Inverter circuit to convert 12VDC to 220V 50Hz AC which is connected in the end of the battery side. The main motive of thecircuits is to charge the battery using multiple sources and use the renewable source more. Herethe Solar panel is connected to the solar switcher and it connected to the relay also the AC to DCConverter / Switcher is connected. The output of from the Relay is connected to the batterydirectly. The inverter is connected with the battery to get AC out to use it in our daily life. Forthe inverter circuit we used C4047B CMOS and 2 IRFZ44 Multivibrator. It uses 2 powerIRFZ44 MOSFETs for driving the output power and the 4047 IC as an Astable multivibratorsoperating at a frequency of around 50 Hz. The IC CD4047 is configured in A stablemultivibrator mode with the help of variable resistor RV1 and capacitor C1. By varying the valueof RV1 we can get a different range of output pulse at Q and Q' pins of CD4047. Consequently,there is a variation in the output voltage at the transformer. The n-channel power MOSFETsIRFZ44 Drain pins are connected with the transformer secondary pins and common pin in thesecondary winding is connected with battery positive. Both MOSFET source pins are connectedto the negative terminal of the battery. When the alternate square pulse from Q & Q' drives theMOSFET, it switches ON. Then the secondary winding is forced to induce an alternate magneticfield. This magnetic field induced produces high alternate voltage around 220V.To manage the system easily we use an Arduino. In every part like in solar charger part, AC toDC switching part, the battery charging part and the inverter part are connected to a Arduino toget all the data like voltage, current etc.Components Used in the CircuitsDiode: The model number of the diode which is used is 1N4007. Peak repetitive reverse voltageEquation of the diode is 1000V. RMS Reverse Voltage is 700V. Average rectified forward currentEquation is 1A. Forward Voltage (Vfm) (at If = 1A) is 1V. Peak Reverse Current at Rated DC BlockingVoltage (@TA = 25°C) is 5 μA.LM317 Voltage Regulator: The LM317 is an adjustable 3-terminal positive voltage regulatorcapable of supplying in excess of 1.5 A over an output voltage range of 1.2 V to 37 V. Thisvoltage regulator is exceptionally easy to use and requires only two external resistors to set theoutput voltage. Further, it employs internal current limiting, thermal shutdown and safe areacompensation, making it essentially blow-out proof. This device can also be used to make aprogrammable output regulator, or by connecting a fixed resistor between the adjustment andoutput, the LM317 can be used as a precision current regulator. Output current in excess of 1.5 Aand output adjustable between 1.2V and 37V.DC Relay: Normal switching capacity of the relay is 10A, 250V AC. Maximum switchingcurrent is 15A and maximum switching voltage is 277V AC. Maximum switching power is2770VA. Initial contact resistance (at 6VDC 1A) is 100 mΩ where the operating time 8msec.and release time 5msec.Mosfet(IRFZ44): The device features very low on state resistance and has integral zener diodesgiving ESD protection up to 2KV. It is intended for use in switched mode power supplies andgeneral-purpose switching applications.It's Drain source voltage (VDS) is 55V. Drain-gate voltage is 55V when is 20 = 20kΩ. Gatesource voltage is 20V. Drain current (DC) =49A. Total power dissipation is 110W.Multivibrator (CD4047): CD4047B consists of a gatable a stable multivibrator with logictechniques incorporated to permit positive or negative edge-triggered monostable multivibratoraction with retriggering and external counting options. Its Supply voltage range is 3 - 18V. DCinput current, any one input is ±10mA. Power dissipation per package is 500mW.LM7812 Voltage regulator: Main features of this voltage regulator is its Output Current is up to1A and output voltages of 5,6,8,9,10,11,12,15,18,24V. Input voltage is 35V. It's maximum lineregulation is 240m V (@VI = 14.5V to 30V TJ = 25 °C). It's maximum load regulation is 240mV (@IO = 5mA to 1.5A, 25 °C). Output noise voltage is 75 μV and dropout voltage is 2V.Non-Polarized Capacitor: It's rated voltage range is 10-100V DC and capacitance range is 1-1000 μF. Operating temperature range is -40 to +85°C. It's maximum leakage current after 5minat +20°C is 0.03CV + 8μA.Arduino Uno: The Arduino is an open-source microcontroller board on the microchipATmega328P microcontroller. The board has 14 Digital I / O pins (6 of them are capable of PWMoutput, 6 Analog I / O. It is programmable with the Arduino IDE via a USB type B. It can bepowered by the USB cable or by an external 9-V DC power source, but it accepts 7 to 20V. Wecan get a 5 v-DC and 3.3V DC output from this board.Transformer: We used a 12-0-12V 1.5 Ampere transformer with the Inverter circuit to make theDC voltage to 220V AC.One more transformer for the AC to DC conversion. It is 12-0-12V 1.5Ampere centre taped with bridge rectifier.Battery: A 12V 14Ampere battery is used in the proposed device to store energy and can be usedusing Inverter.Figure 1. Schematic diagram the system according to the embodiment of the present invention.Figure 2. Circuit diagram of a single diode model according to the embodiment of the presentinvention.

[014] Without further elaboration, the foregoing will so fully illustrate my invention, that othersmay, by applying current of future knowledge, readily adapt the same for use under variousconditions of service. It should also be realized by those skilled in the art that such equivalentconstructions do not depart from the spirit and scope of the invention.Advantages over the prior art

[015] A domestic inverter with renewable battery proposed by the present invention has thefollowing advantages over the prior art:1. Cost Efficiency: By utilizing renewable energy sources (like solar power) and combiningthem with a battery backup, the system reduces reliance on costly non-renewable energysources. The initial installation cost is offset by long-term savings on electricity bills.2. Environmental Impact: The system minimizes the use of fossil fuels, thereby reducinggreenhouse gas emissions and mitigating global warming. The primary energy source isrenewable, which is crucial for sustainable living.3. Energy Security: The combination of solar power, AC backup, and a battery ensures thatenergy is available at all times. This hybrid approach provides a reliable power supply evenwhen sunlight is insufficient or during power outages.4. Flexibility and Control: The integration of various power sources and a monitoring systemallows for dynamic switching based on availability and demand. This ensures efficient energyuse and provides real-time data on system performance.5. Low-Cost Conversion: The design of a low-cost 100 W DC to AC converter makesrenewable energy more accessible for residential applications. This cost-effective approachpromotes wider adoption of renewable energy systems.6. Enhanced Monitoring and Management: The use of an Arduino for monitoring andcontrolling various components of the system allows for precise management of energysources, battery levels, and output voltage, improving overall system efficiency andreliability.

[016] In the preceding specification, the invention has been described with reference to specificexemplary embodiments thereof. It will be evident that various modifications and changes maybe made thereunto without departing from the broader spirit and scope of the invention as setforth in the claims that follow. The specification and drawings are accordingly to be regarded inan illustrative rather than restrictive sense. Therefore, the aim in the appended claims is to coverall such changes and modifications as fall within the true spirit and scope of the invention. Thematter set forth in the foregoing description and accompanying drawings is offered by way ofillustration only and not as a limitation. The actual scope of the invention is intended to bedefined in the following claims when viewed in their proper perspective based on the prior art.

Claims

1. A domestic inverter with renewable battery which consists of: - a solar panel configured to generate DC power; - an AC power source configured to provide AC power; - a DC battery configured to store energy; - a solar panel switcher circuit for converting and regulating the DC power from the solar panel to charge the DC battery; - an AC to DC converter for converting the AC power to DC power for charging the DC battery; - a relay circuit configured to switch the charging source between the solar panel and the AC power source based on the battery charge level; - an inverter circuit configured to convert the DC power from the battery to AC power for use in residential applications; - a monitoring system integrated with an Arduino microcontroller for tracking battery charge levels, output voltage, and managing the switching of power sources.

2. A domestic inverter with renewable battery as claimed in claim 1 wherein the solar panel is an 18V 50W solar panel.

3. A domestic inverter with renewable battery as claimed in claim 1 wherein the battery is a 12V 14 Ampere battery.

4. A domestic inverter with renewable battery as claimed in claim 1 wherein the solar panel switcher includes an LM317 voltage regulator for regulating the charging voltage and current.

5. A domestic inverter with renewable battery as claimed in claim 1 wherein the AC to DC converter utilizes a transformer with a 12-0-12V center tap and a bridge rectifier for converting 220V AC to 14V DC.

6. A domestic inverter with renewable battery as claimed in claim 1 wherein the inverter circuit includes a CD4047B CMOS multivibrator and two IRFZ44 MOSFETs for generating 220V AC from 12V DC.

7. A domestic inverter with renewable battery as claimed in claim 1 wherein the monitoring system is configured to automatically deactivate the inverter if the output voltage is less than 220V.

8. A domestic inverter with renewable battery as claimed in claim 1 wherein the relay circuit is configured to automatically switch to the AC power source when the DC battery is depleted.

9. A domestic inverter with renewable battery as claimed in claim 1 wherein the Arduino microcontroller is programmed to monitor voltage and current levels and control the switching of the power sources and inverter operation.

10. A domestic inverter with renewable battery as claimed in claim 1 wherein the solar panel switcher includes a diode (D1) for preventing reverse current flow from the battery.