WO2014087426A2

WO2014087426A2 - A system and a method for charging battery in electric vehicles using non-conventional energy sources

Info

Publication number: WO2014087426A2
Application number: PCT/IN2013/000744
Authority: WO
Inventors: Prakash Ramaraju; Neel Mathews; Kartik Gopal
Original assignee: Mahindra Reva Electric Vehicles Private Limited
Priority date: 2012-12-05
Filing date: 2013-12-04
Publication date: 2014-06-12
Also published as: WO2014087426A3

Abstract

A system for charging battery in a vehicle includes at least one of a main power inlet configured to receive energy from a main power supply unit and an non conventional power inlet configured to receive energy from a non conventional power supply unit and a controller configured to regulate functioning of at least one of the main power inlet, the non conventional power inlet and the battery. Further, the controller is configured to measure energy requirement of the battery and control the energy supplied from at least one of the main power supply unit and the non conventional power supply unit to the battery based on the energy requirement of battery.

Description

A SYSTEM AND A METHOD FOR CHARGING BATTERY IN ELECTRIC VEHICLES USING NON-CONVENTIONAL ENERGY SOURCES

FIELD OF INVENTION

The embodiments herein relate to an energy management system, and more particularly but not exclusively to an energy management system that could be used with a vehicle propelled by a motor, such as electric vehicles and hybrid vehicles, for achieving desired charging of battery

BACKGROUND OF INVENTION

[001] In the past two decades, there has been a significant increase in the usage of motor vehicles. People use motor vehicles for transportation purposes and several other purposes such as trading of goods and services from one place to another. Most of the motor vehicles today are usually powered by internal combustion engine. Source of energy for the internal combustion engines are fossil fuels such as diesel and petroleum. Although, internal combustion engines provide necessary power output, the energy sources such as diesel and petroleum used for internal combustion engines are not renewable and can cause environmental pollution. Further, various studies reveal that the fossil fuels are depleting at a rapid pace and as a result the prices of fossil fuels have also been increased enormously in the past decade. Further, burning of fossil fuels in the combustion engines results in the emission of harmful gases (pollutants) such as hydrocarbons, nitrous oxides and carbon monoxide, which are harmful to the environment.

[002] The problems associated with the conventional motor vehicles powered by internal combustion engines have been partially solved with the invention of vehicles such as electric vehicles that are powered by motor. The electric vehicles include a motor and a battery configured to store electrical energy. The motor is configured to receive electrical energy from the battery and generates mechanical energy required to drive the vehicle. Although, electric vehicles overcome the problems associated with the internal combustion engine by avoiding the need for fossil fuel and by preventing the production of harmful gases, it should be noted that the efficiency of charging the battery in the electric vehicle is not up to the desired level. For example, in the conventional electric vehicle, the batteries are charged from conventional charging station. Further, due to the limited storage capacity, the batteries are configured to store the electrical energy for normal every day usage. However, in practical usage, at times when there is a need for excess electric energy (driving longer distance), the conventional method of charging the battery is not able to deliver the desired electrical energy. Furthermore, the cost associated with the charging process in conventional charging station is also high. Although, there exists a technology of using solar energy to charge the battery, it should be noted that the conventional process of charging the battery using solar energy works only at times when there is a sufficient amount of sun light. Furthermore, the process of charging the battery using solar energy is a time consuming process and may not work efficiently at times when there is an immediate need of energy.

[003] Therefore, there is a need for an energy management system that could charge the battery based on the customer needs such as minimum planned distance to travel during or after the charging process. Further, there is a need for an energy management system that makes the charging process relatively cheaper when compared to the conventional charging process. Furthermore, there is a need for an energy management system that could overcome the aforementioned drawbacks of existing technologies. OBJECT OF INVENTION

[004] The principal object of this invention is to provide an energy management system that could provide un-interrupted energy supply to the battery.

[005] Another object of the invention is to provide an energy management system that could reduce the cost associated with the process of charging the battery in electric vehicles.

[006] A further object of the invention is to provide an energy management system that could effectively manage at least one of the non-conventional energy sources to charge the electric vehicle.

[007] A further object of the invention is to provide an energy management system that could maximize the use of non conventional energy sources to charge the battery of a vehicle while achieving battery requirement.

[008] Yet another object of the invention is to provide an energy management system that could overcome the aforementioned drawbacks of the conventional charging process.

[009] These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications. BRIEF DESCRIPTION OF FIGURES

[0010] This invention is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:;

[0011] Fig. 1 is a block diagram depicting architecture of the energy management system according to an embodiment of the present invention;

[0012] Fig. 2 is a block diagram depicting architecture of the energy management system according to another embodiment of the present invention;

[0013] Fig. 3 is a block diagram depicting architecture of the energy management system according to yet another embodiment of the present invention; and

[0014] Fig. 4 is a flowchart depicting the method for charging battery in an electric vehicle according to an embodiment of the present invention.

DETAILED DESCRIPTION OF INVENTION

[0015] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-Umiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well- known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. For example, it should be noted that while some embodiments are explained with respect to an energy management system for use in electric vehicles for the ease of describing, it should be noted that the energy management system as disclosed in the present invention could also be used for any other devices such as hybrid vehicles and so on by incorporating the subject matter of the invention with little or no modifications. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0016] The embodiments herein provide an energy management system that could provide un-interrupted energy supply to the battery. Further, the embodiments herein provide an energy management system that could reduce the cost associated with the process of charging the battery in electric vehicles. Referring now to the drawings, and more particularly to FIGS. 1 through 4, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.

[0017] Fig. 1 is a block diagram depicting architecture of an energy management system according to an embodiment of the present invention. In an embodiment, the energy management system 100 includes a main power inlet configured to receive energy from a main power supply unit 102, a non conventional power inlet configured to receive energy from a non conventional power supply unit 104 and a controller 106. In one embodiment, the energy management system 100 is configured to regulate the energy supply to an electric vehicle 200. The electric vehicle 200 includes a battery 202 and an on-board charger 204. The battery 202 is configured to store the electrical energy. Further, the battery 202 is configured to supply electrical energy to a motor of the electric vehicle. The on-board charger 204 is configured to supply electrical energy from the main power supply unit 102 to the battery 202.

[0018] In one embodiment, the main power supply unit 102 is a three phase AC power supply. However, it is also within the scope of invention that the main power supply unit 102 could be selected from any other type of systems without otherwise deterring the intended function of the main power supply unit 102 as can be deduced from this description. Further, the on-board charger 204 is configured to receive the energy from main power supply unit 102 and charge the battery 202. In an embodiment, the on-board charger 204 is configured to perform energy conversion on the energy received from main power supply unit 102 to suit the energy that could be stored in the battery 202. In one embodiment, the on-board charger 204 is configured to receive AC power from the main power supply unit 102 and convert the AC power to DC power to suit the needs of the battery 202.

[0019] In one embodiment, the non conventional power supply unit 104 is selected from photovoltaic panels that are configured to generate electrical energy from solar energy. However, it is also within the scope of invention that the non conventional power supply unit 104 is selected from any other non conventional energy source such as but not limited to wind power, hydro power, bio mass, bio fuel and geothermal energy without otherwise deterring the intended function of the non conventional power supply unit 104 as can be deduced from this description. The non conventional power supply unit 104 is configured to supply energy to the battery 202. In an embodiment, the non conventional power supply unit 104 is configured to generate DC power. Further, the DC power generated by the non conventional power supply unit 104 is supplied to the battery 202. The controller 106 is a programmable unit and configured to regulate functioning of at least one of the main power supply unit 102, non conventional power supply unit 104, on-board charger 204 and battery 202. In an embodiment, the controller 204 is configured to measure the energy requirement for the battery 202 and control the energy supplied to the battery 202 from at least one of the main power supply unit 102 and non conventional power supply unit 104 based on the energy requirement of the battery' 202. In an embodiment, the energy supplied to the battery 202 is controlled based on at least one of state of charge of battery, state of health of battery, environmental conditions, characteristics preprogrammed in the controller, instruction fed by the user and instruction received from remote server. Further, the controller 204 is configured to control the energy supplied to the battery 202 from at least one of the main power supply unit 102 and non conventional power supply unit 104 such that the controller 204 prevents the energy supply from the main power supply unit 102 to the battery 202, if the energy supplied from non conventional power supply unit 104 is sufficient to meet the energy requirements of the electric vehicle 200.

[0020] In one embodiment, the energy supplied to the battery 202 is controlled based on state of charge of battery. The user can fix an optimum energy level that has to be maintained in the battery 202. Further, the controller 204 is configured to determine the current state of charge of battery and compare the current state of charge of battery with the optimum energy level that has to be maintained in the battery. Furthermore, if the energy level in the battery is below the optimum energy level, the controller is configured to alert the user to connect at least one of the main power supply unit 102 and non conventional power supply unit 104 to the electric vehicle 200 to charge the battery 202. Further, if the energy level in the battery 202 reaches the optimum energy level, the controller 204 is configured to alert the user to disconnect the corresponding power supply unit from the battery 202. In another embodiment, the controller 204 is configured to prevent the energy supply to the battery 202 automatically, once the energy level in the battery reaches the optimum energy level. In an embodiment, the optimum energy level is determined by the controller automatically based on historical data such as daily usage of the electric vehicle, state of health of the battery and environmental conditions under which the vehicle will be operated. In another embodiment, the optimum energy level is determined, such that the optimum energy level produces high performance in the battery 202.

[0021] In another embodiment, the energy supplied to the battery 202 is controlled based on state of health of battery. The controller is configured to determine the current state of health of battery 202. Further, the optimum state of health of battery that needs to be maintained for high performance of battery is identified and compared with the current state of health of battery. Furthermore, the energy supply to the battery 202 is controlled based on the current state of health of battery such that the battery gives high performance.

[0022] In another embodiment, the energy supplied to the battery 202 is controlled based on the environmental conditions under which the vehicle is operated. The control is configured to receive information based on the environmental conditions under which the vehicle is/will be operated. For example, if the vehicle is operated in a cloudy conditions or conditions in which there is no or limited solar radiations, the controller 106 is configured to charge the battery 202 from the energy supplied from main power supply unit 102. Furthermore, if the vehicle is operated under conditions in which there is sufficient amount of solar radiations that could be 13 000744

used by the non conventional power supply unit 104 to produce electricity, the controller 106 is configured to charge the battery 202 from the energy supplied from non conventional power supply unit 102. The controller is configured to receive information based on environmental conditions from means such as GPS enabled devices, internet and so on.

[0023] In another embodiment, the energy supplied to the battery 202 is controlled based on the characteristics preprogrammed in the controller. The controller 204 is a programmable unit and is programmed to determine the availability of solar energy at any particular instant. Further, the controller 204 is programmed to determine any additional requirement for energy. For example, the controller 204 is configured to determine any additional requirement for energy based on the data such as daily usage of electric vehicle, speed at which the vehicle is operated, energy utilized for other electro mechanical components in the vehicle and so on. Furthermore, the controller 204 is configured is configured to supply energy from at least one of the main power supply unit 102 and non conventional power supply unit 104 based on the characteristics preprogrammed in the controller. The controller is configured to prioritize the non conventional power supply unit 104 for charging the battery 202.

[0024] In another embodiment, the energy supplied to the battery 202 is controlled based on the instruction fed by the user. The controller 204 is configured to receive information from the user on at least one of the distance o^{^} travel, time within w ch the charging has to be performed, other electro mechanical devices that could be used and so on. Further, the controller 204 is configured to control the energy supplied from at least one of the main power supply unit 102 and non conventional power supply unit 104 to the battery based on the information received from the user. For example, if the user gives the information on the distance to travel, the controller 204 is configured to charge the battery 202 from the energy supplied from non conventional power supply unit 104. Further, if the energy generated by the non conventional power supply unit 104 is not sufficient to fulfill the energy requirement of the battery 202, the controller 204 is configured to receive energy from the main power supply unit 102. Similarly, if the user gives the information on the time within which the charging has to be performed, the controller 204 is configured to charge the battery 202 from the energy supplied from non conventional power supply unit 104. Further, if the energy generated by the non conventional power supply unit 104 is not sufficient to fulfill the energy requirement of the battery 202 within the time limit, the controller 204 is configured to receive energy from the main power supply unit 102 to fulfill the energy requirement of the battery 202 within the time limit.

[0025] In another embodiment, the energy supplied to the battery 202 is controlled based on the instruction received from the remote server. The controller 204 is configured to receive information such as environmental condition under which the vehicle is operated, state of health of battery, state of charge of battery, historical data on various parameters and so on from the remote server. Further, the controller 204 is configured to control the energy supplied from at least one of main power supply unit 102 and non conventional power supply unit 104 based on the information received from the remote server. In an embodiment, the controller 204 is configured to receive information on the tariff of electric charges from the remote server. Further, the controller controls the energy supply from at least one of main power supply unit 102 and non conventional power supply unit 104 based on the information on the tariff of electric charges. For example, differential tariff structures are in force in many countries. Differential tariff structure is that the electricity charges are different at different times based on state of grid (loading). The controller is configured to receive information on the differential tariff structure from the remote server and the controls the energy supply from at least one of main power supply unit 102 and non conventional power supply unit 104 based on the differential tariff structure in addition to time duration for charging.

[0026] In one embodiment, the electric vehicle 200 is configured to receive energy from either one of main power supply unit (AC power) 102 or non conventional power supply unit (DC power) 104 at a given time period. Fig. 2 is a block diagram depicting architecture of an energy management system according to an embodiment of the present invention. Further, the controller 204 is configured to direct the energy supplied from the main power supply unit 102 or non conventional power supply unit 104 to the on-board charger 204 or the battery 202 correspondingly to suit the energy requirement of the battery 202. For example, if the energy received by the electric vehicle is supplied from the non conventional power supply unit 104 (DC power), the controller 204 is configured to direct the energy received from the non conventional power supply unit 104 to the battery 202. Furthermore, if the energy received by the electric vehicle is supplied from the main power supply unit 102 (AC power), the controller 204 is configured to direct the energy received from the main power supply unit 102 to the onboard charger 204. The on-board charger 204 is configured to receive the energy from main power supply unit 102 and charge the battery 202. In an embodiment, the on-board charger 204 is configured to perform energy conversion on the energy received from main power supply unit 102 (AC power) to suit the energy that could be stored in the battery 202 (DC power). Further, the energy supplied to the battery 202 is controlled based on at least one of state of charge of battery, state of health of battery, environmental conditions, characteristics preprogrammed in the controller, instruction fed by the user and instruction received from remote server. In an embodiment, the controller 204 is configured to control the energy supplied to the battery 202 from at least one of the main power supply unit 102 and non conventional power supply unit 104 such that the controller 204 prevents the energy supply from the main power supply unit 102 to the battery 202, if the energy supplied from non conventional power supply unit 104 is sufficient to meet the energy requirements of the electric vehicle 200.

[0027] In another embodiment, the electric vehicle 200 is configured to receive only the

AC power. Fig. 3 is a block diagram depicting architecture of an energy management system according to an embodiment of the present invention. Further, the energy management system 100 includes a power maximizer 108 and an inverter 110. The power maximizer 108 is configured to receive the DC power supplied from the non conventional power supply unit 104. Further, the power maximizer 108 is configured to amplify the received power and direct it to the inverter 110. The inverter 110 is configured to convert the received DC power into AC power such that it could be supplied to the electric vehicle 200. Further, the energy supplied to the battery 202 is controlled based on at least one of state of charge of battery, state of health of battery, environmental conditions, characteristics preprogrammed in the controller, instruction fed by the user and instruction received from remote server. In an embodiment, the controller 204 is configured to control the energy supplied to the battery 202 from at least one of the main power supply unit 102 and non conventional power supply unit 104 such that the controller 204 prevents the energy supply rrom the main power supply unit 102 to the battery 202, if the energy supplied from non conventional power supply unit 104 is sufficient to meet the energy requirements of the electric vehicle 200.

[0028] In another embodiment, the communication between the energy management system 100 and the electric vehicle 200 is enabled by a communication module 112. The communication module is selected from at least one of wired or wireless means. However, it is also within the scope of invention that the communication module 112 could include any other forms of communication means such as using optical fibers and so on that the person skilled in the art could recognize without other deterring the intended function of the energy management system 100 and the electric vehicle 200 as could be deduced from this description. Further, the excess energy generated by the non conventional power supply unit 104 is supplied back to an excess power storage system 114, where it could be stored and utilized for other purposes such as household purposes. For example, if at a given point of time, the unconventional power supply unit 104 is capable of generating more power (excess power) after meeting the energy requirement of battery, the excess power is sent back to the energy management system, where it could be stored in the excess power storage system 114 and utilized for other purposes. In an embodiment, the excess power storage system 114 is a grid energy storage system. However, it is also within the scope of invention that the excess power storage system 114 could be selected from any other system that could store and distribute energy for other requirements. In another embodiment, the excess energy stored in the energy storage system could be utilized by battery 202 when there is an energy requirement in the battery 202.

[0029] It should be noted that the aforementioned configuration of energy management system 100 and electric vehicle 200 are provided for the ease of understanding of the embodiments of the invention. However, certain embodiments may have a different configuration of the components of energy management system 100 and electric vehicle 200 and certain other embodiments may exclude certain components of the energy management system 100 and electric vehicle 200. Therefore, such embodiments and any modification by addition or exclusion of certain components of the energy management system 100 and the electric vehicle 200 without otherwise deterring the intended function of the energy management system 100 as is apparent from this description and drawings are also within the scope of this invention.

[0030] A method for charging battery in electric vehicles is explained herein below. Fig. 4 is a flowchart depicting the method for charging battery in an electric vehicle according to an embodiment of the present invention. The method 300 for charging battery in electric vehicles includes providing at least one of a main power supply unit 102, an non conventional power supply unit 104 and a controller 106 (step 302). Further, the energy requirement of the battery 202 is identified based on at least one of state of charge of battery, state of health of battery, environmental conditions, characteristics preprogrammed in the controller, instruction fed by the user and instruction received from remote server (step 304). The availability of solar energy, at any instant, which could be utilized by the non conventional power supply unit 104 for generating electrical energy, is identified by the controller (step 306). The additional requirement of the energy is identified by the controller (step 308). Further, the controller 204 is configured to optimally combine the energy supplied from main power supply unit 102 and an non conventional power supply unit 104 to meet the energy requirement of the battery 202 (Step 310). The controller is configured to prioritize the energy supplied from non conventional power supply unit 104 for charging the battery 202 (Step 312).

[0031] It should be noted that the aforementioned steps for charging battery in electric vehicles are provided for the ease of understanding of the embodiments of the invention. However, various steps provided in the above method may be performed in the order presented, in a different order, or simultaneously. Further, in some embodiments, one or more steps listed in the above method may be omitted. Therefore, such embodiments and any modification that is apparent from this description and drawings are also within the scope of this invention. [0032] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

Claims

We claim

A system for charging battery in a vehicle, said system comprising:

at least one of a main power inlet configured to receive energy from a main power supply unit and a non conventional power inlet configured to receive energy from an non conventional power supply unit; and

a controller configured to regulate functioning of at least one of said main power inlet, said non conventional power inlet and said battery, wherein

said controller is configured to measure energy requirement of said battery and control the energy supplied from at least one of said main power supply unit and said non conventional power supply unit to said battery based on said energy requirement of battery.

The system as claimed in claim 1, wherein said energy requirement of battery is measured based on at least one of state of charge of battery, state of health of battery, environmental conditions, characteristics preprogrammed in the controller, instruction fed by the user and instruction received from remote server.

The system as claimed in claim 1, wherein said controller is configured to supply energy from said main power supply unit to said battery, if the energy supplied from un- conventional power supply unit is not sufficient to meet said energy requirement of battery.

4. The system as claimed in claim 1 further includes an on-board charger, wherein said onboard charger is configured to convert the type of energy received from at least one of said main power supply unit and said non conventional power supply unit to the type of energy that could be stored in said battery.

5. The system as claimed in claim 1 further includes a sensor provided in communication with said controller, wherein said sensor is configured to retrieve information on at least one of state of charge of battery and state of health of battery.

6. The system as claimed in claim 1, wherein said controller is configured to receive instruction fed by the user through mobile phone.

7. The system as claimed in claim 1 further includes at least one mechanism configured to receive, store and utilize excess energy generated by said non conventional power supply unit.

8. The system as claimed in claim 1, wherein

said main power supply unit is selected from a three phase AC power supply system and configured to supply AC power; and

said non conventional power supply unit is selected from devices that are configured to generate electrical energy from energy sources that are naturally replenished.

9. A method for charging battery in a vehicle, said method comprising:

providing at least one of a main power supply unit and a non conventional power supply unit;

determining energy requirement of said battery; and optimally combining the energy supplied from said main power supply unit and said non conventional power supply unit to meet the energy requirement of said battery.

10. The method as claimed in claim 9, wherein said energy requirement of battery is determined based at least one of state of charge of battery, state of health of battery, environmental conditions, characteristics preprogrammed in the controller, instruction fed by the user and instruction received from remote server.

11. The method as claimed in claim 9, wherein said process of determining energy requirement of battery further includes determining additional energy requirement of battery.

12. The method as claimed in claim 9 further includes prioritizing the energy supplied from said non conventional power supply unit for charging said battery.

13. The method as claimed in claim 9 further includes utilizing excess energy generated by said non conventional power supply unit.