Implementation And Simulation Of Charging Circuit

Transcript

International Journal of Electrical, Electronics and Computer Systems, (IJEECS) _______________________________________________________________________ IMPLEMENTATION AND SIMULATION OF CHARGING CIRCUIT SUITABLE FOR DRIVING A DC MOTORS 1 Chandra Mouli B R, 2Manjunatha D V, 3Mohammed Abuzar, 4K.R.Nataraj 1,2,3,4 Department of ECE, SJBIT, Bangalore Email : [email protected], [email protected], 3 [email protected], [email protected] 1 limited to four-wheeler. There is a need to introduce the hybrid concept on two-wheeler in fact more of the vehicular population drives on two-wheeler in India. Abstract— The implementation and simulation of charging circuit suitable for driving hybrid two-wheeler vehicle incorporates two different types of charging methodology for charging a lead-acid battery. The powered battery is later been utilized for driving a BLDC motor which drives the vehicle. To charge the battery the wall charger and solar power is been used, where wall charger is the regular AC mains after suitable rectification the dc output is obtained. And as we know the solar power is directly proportional to the sun’s radiation and the sun radiation is not constant always, so we decided to make use of DC-DC buck-boost convertor at the output of solar which can give a constant output voltage. We would also like to mention that the electric power utilised for driving a two-wheeler make the vehicle a hybrid two-wheeler vehicle which is incorporated of more than one source. The motor controller for controlling of BLDC motor and other parameters in the hybrid two-wheeler vehicle make use of regenerative braking intern for charging the battery, where the motor will act as a generator when ever braking is applied. The solar power and the regular AC mains are the two types of charging methodology used in our project. As we know that the solar power is not always constant it varies on the variation of sun’s radiation, this variation might cause the output of the solar panel to be varying hence there is a need of using DC-DC buck-boost convertor which is responsible for maintaining a constant DC voltage at the output. Another type of charger is the AC mains charger which involves rectification which yields to a DC output. The two types of DC output can be used at our convenience to charge the battery. The powered battery is utilized to run the motor through motor controller which involves or is responsible for prevention of overheating, automatic or manual means of starting or stopping the motor, rotation of motor in clockwise or anti-clockwise direction and also speed of the motor. I. INTRODUCTION II. BLOCK DIAGRAM In various concerns there is a growing interest in electric and hybrid electric vehicles due to environmental concerns and fuel deficiency. Recent efforts are directed toward developing an improved propulsion system for electric and hybrid-electric vehicles applications. Acmains The vehicle dynamics have been studied by us in an attempt to find a suitable electric propulsion system in an existing IC (internal combustion) engine two-wheeler. This project is aimed at developing the system new design philosophies of electric and hybrid vehicle propulsion systems to be implemented on an existing two-wheeler, using this concept two-wheelers can be effectively transformed to hybrids by which fuel efficiency can be achieved. As we can see the electric and hybrid revolution is on its full swing now, but it is Solar panel Charging circuit for AC mains Battery Charging circuit for solar panel DC motor Fig 1: General block Diagram of implementation of charging circuit suitable for driving a DC motor. __________________________________________________________________________ ISSN (Online): 2347-2820, Volume -1, Issue-2, 2013 53 International Journal of Electrical, Electronics and Computer Systems, (IJEECS) _______________________________________________________________________ The block diagram is as shown in the figure 1.1 and the operation regarding it is explained in such a way that mechanical driving system and electric driving system was divided into two blocks and the system was connected to driving wheel. In mechanical Drive system the conventional fuel vehicles use this type of system. The fuel in the combustion engine is ignited and is given to the gear box and then to the wheels. In electric drive system the battery power is used to drive the motor. Hence at the time of accelerating the vehicle the battery discharges and at the time of slowing down the vehicle battery charges due to regenerative braking concept. Hence hybrid electric vehicle (HEV) uses both these drive systems for its motion by which fuel efficiency is obtained. In our project lead acid battery is used because of its robustness, inexpensive and simple to manufacture in terms of cost per watt hours and low maintenance. We would also like to mention that there is an another type of charging technique which is internally been handled by the motor controller known as Regenerative braking. LTC3862 is an IC used for charging battery using solar, LM317 is an IC used for charging battery from AC mains and other components related to both charging circuits like resistor and capacitor etc. A battery, solar panel, motor controller and a hub motor. The battery block is interfaced with the motor controller block; the motor controller controls all the functional capabilities and is the central component of the system. The basic requirement for the control is to regulate the amount of power applied to the motor, especially for DC motors. The motor controller can be adjusted to synchronize with other brushless motors. There are also many built-in functions for this controller that vary from detecting any malfunctions with the motor hall sensors, the throttle, and the brake levers to protect functions against excessive current and under-voltage, which are ideal for protecting the battery. These functions are beneficial to the success of this project and also provide a solution to any troubleshooting and damages that may occur. The throttle/cruise controller is one of a terminal of motor controller that is used to trigger for increasing speed of a vehicle. One source of battery charging comes from the photovoltaic solar panel, once a voltage and current is generated through the solar panel a DC – DC boost converter block is needed to step the output voltage from the solar panel to match the battery’s voltage of 48V. The battery block is interfaced with the motor controller block. The motor controller controls all the functional capabilities and is the central component of the system. The basic requirement for the control is to regulate the amount of power applied to the motor, especially for DC motors. The motor controller can be adjusted to synchronize with other brushless motors. There are also many built-in functions for this controller that vary from detecting any malfunctions with the motor hall sensors, the throttle, and the brake levers to protect functions against excessive current and under-voltage, which are ideal for protecting the lead- acid battery. These functions are beneficial to the success of this project and also provide a solution to any troubleshooting and damages that may occur. 2. III. METHODOLOGY There are many key components within the block diagram for this system as was shown in block diagram. They consist of a lead-acid battery, a motor controller, a DC-DC converter, a photo-voltaic solar panel, and a brushless DC motor. The power source for the system was a DC battery source chosen to output 48V. A lead-acid battery was the most efficient choice for hybrid two-wheeler because it offers high discharge rates, robust in nature, more number of rechargeable cycles, inexpensive and low maintenance can be obtained. One key feature that is integrated with the interface of the controller and the motor was the regenerative braking. A regenerative brake is an energy recovery mechanism that reduces the two-wheeler speed by converting some of its kinetic energy into a useful form of energy instead of dissipating it as heat from conventional brake friction. The energy is then supplied back to the power source. The control allows the battery to interface with the motor to be bidirectional which can supply and receive power by creating a switch that purposely is fooling the controller to use the motor as a generator without completely breaking the wheel. One key feature that is integrated with the interface of the controller and the motor was the regenerative braking. A regenerative brake is an energy recovery mechanism that reduces the vehicle speed by converting some of its kinetic energy into a useful form of energy instead of dissipating it as heat from conventional brake friction. The energy is then supplied back to the power source. The control allows the battery to interface with the motor to be bidirectional which can supply and receive power. The basic advantage with a using of hub motor is that, there is no need for external mounting brackets and drive chains to support a motor and transmission. Instead all of this is contained inside the wheel which mounts on your bike like any other wheel. 1. Software requirements: Multisim and LTspice Another source of battery charging comes from the photovoltaic solar panel. Once a voltage and current is generated through the solar panel a DC – DC buck-boost converter block is needed to step the output voltage from the solar panel to match the battery’s voltage of 48V. A. DC-DC buck-boost convertor: Including the solar panel into the electric bicycle not only presents an extra source for charging the battery, but also an extra problem. The problem is that the output Hardware requirements: __________________________________________________________________________ ISSN (Online): 2347-2820, Volume -1, Issue-2, 2013 54 International Journal of Electrical, Electronics and Computer Systems, (IJEECS) _______________________________________________________________________ of the solar panel will not always be stable due to fluctuations in intensity of sunlight, angular changes with respect to the direction of sunlight, as well as other environmental factors. This is where the Boost Converter comes into our project. The output of the solar panel will be the input of the boost converter, which then outputs into the battery for charging. Because the output of the solar panel will be varying constantly, we need a boost converter that will take an input from a wide range of voltages and output a specific, constant voltage value. A boost converter is a step-up power converter that will take in a DC voltage and output a higher value DC voltage. Our boost converter will require us to take in the output of the solar panel, which can range from 0V to 17.2V, and output 54.6V for optimal charging of the battery. power MOSFETs. Two phase operation reduces system filtering capacitance and inductance requirements. The 5V gate drive is optimized for most automotive and industrial grade power MOSFETs. Adjustable slope compensation gain allows the user to fine-tune the current loop gain, improving noise immunity. The operating frequency can be set with an external resistor over a 75 kHz to 500 kHz range and can be synchronized to an external clock using the internal PLL. Multi-phase operation is possible using the SYNC input, the CLKOUT output and the PHASEMODE control pin allowing 2-, 3-, 4-, 6- or 12-phase operation. Other features include an internal 5V LDO with under voltage lockout protection for the gate drivers, a precision RUN pin threshold with programmable hysteresis, soft-start and programmable leading edge blanking and maximum duty cycle. C. Motor Controller: To drive and control the BLDC motor, the use of a motor controller was implemented. The motor controller is an essential device for any motor driven device. The motor controller is analogous to the human brain, processing information and feeding it back to the end user. To drive the BLDC motor, the motor controller sends rectangular/trapezoidal voltage stokes that are coupled with the position of the rotor. The voltage stokes of the BLDC motor need to be applied to the two phases of the 3-phase winding system so that the angle between the stator, flux and the rotor flux is kept close to 90 degrees in order to generate maximum torque from the motor. In order to do that, the motor controller is used to electronically control when the voltage strokes are applied. Fig 2: circuit diagram of LTC3862 After researching websites, we came upon two different evaluation module boards the TPS40210EVM from Texas Instruments and the LTC3862 from Linear Technology. The inputs to the controller include the speed and current signals that are supplied by the throttle. The DC power supply feeds power to the motor controller, which then distributes the voltage and current necessary to drive the BLDC motor. The Hall Effect sensors provide the feedback needed for the motor to know the position of the rotor and to tell it when to supply the voltage stoke to the different phases of the BLDC motor. Of course, the applications of a motor controller vary based on the task that it will be performing. One of the simplest applications is a basic switch to supply power to the motor, thus making the motor run. As one utilizes more features in the motor, the complexity of the motor controller increases. We were initially come through the Texas Instruments Evaluation Module TPS40210EVM because it has the characteristics of taking in an input range of 9.6V to 13.2V and outputting 24V at a maximum of 2 amps. This EVM has a small area which makes it very feasible to be placed anywhere on the bike. We originally thought that since the battery is rated at 48V, we would need to supply exactly 48V in order to charge it. This could be done by using a simple voltage doubler added to the output of the EVM and we should be theoretically having the appropriate 48V needed for charging The Linear Technology Evaluation Module DC1286A-A (LTC3862) seemed very nice for our application. This EVM operates at an input range of 5V to 36V. It outputs a constant 48V with an output current of 2A-5A. Initially, this evaluation module is the perfect fit for charging our battery because it takes an input in the range of our solar panel, but it also outputs the exact amount of voltage needed to charge the battery. D. Solar cells/panel: The lead acid battery is charged with solar energy with the help of a solar cell. Solar cells convert the energy of sunlight directly into electricity through the use of the photovoltaic effect. The photovoltaic effect involves the creation of a voltage into an electro-magnetic radiation. The photoelectric and photovoltaic effects are related to sunlight, but are different in that electrons are ejected B. Description of LTC3862: The LTC3862 is a two phase constant frequency, current mode boost and SEPIC controller that drives N-channel __________________________________________________________________________ ISSN (Online): 2347-2820, Volume -1, Issue-2, 2013 55 International Journal of Electrical, Electronics and Computer Systems, (IJEECS) _______________________________________________________________________ from a material’s surface upon exposure to radiation of sufficient energy in photoelectric, and generated electrons are transferred to different bands of valence to conduction within the material, resulting in the build-up of voltage between two electrodes in photovoltaic. current, voltage and waveforms involved because the software does not allow multiple parameters involving and if it was possible also then it had been made this snapshot clumsy. This module converts the AC input of 230Volts, to a usable DC output greater than 17V for the charger circuit. The design includes an internal transformer, bridge rectifier and a filter capacitor. Input signal from the outlet lowered to 16Vrms,16Vrms gets rectified going through the full-bridge rectifier, with 2 diode voltage drop loss(~1.4V),Capacitor is charged to peak value of the signal, Capacitor is discharged by the rest of the circuit until the voltage on the capacitor isn’t increased by the rectified AC signal wave. Solar cells are electrically connected and fabricated as a module with a sheet of glass on top to allow light to pass and protect the semiconductor from the weather. To obtain a desired peak DC voltage we will add solar cells in series, and to obtain a desired peak current, the solar cells are put in parallel position. E. Lead acid battery Lead acid batteries are one of the most popular types of battery in electronics. Although slightly lower in energy density than lithium metal, lead acid is safe, provided certain precautions are met when charging and discharging. This have a many advantages over other conventional types of batteries, the lead acid battery is the optimum choice for a solar assisted two wheeler. Current supplied from battery indicates the flow of energy from the battery and is measured in amperes (or Amps) .The higher the current flow faster the battery will discharge. A battery is rated in amperehours (abbreviated Ah) and this is called the battery capacity. This project revolves around supplying and utilizing energy within a high voltage battery. It demands for a battery with longer running hours, lighter weight with respect to its high output voltage and higher energy density. Among all the existing rechargeable battery systems, the lead acid cell technology is the most efficient and practical choice for the desired application. The battery chosen for this project was a high capacity lead acid battery pack designed specifically for vehicles. Plastic casing is provided to house the internal components of the battery Fig3: Simulation result of buck-boost convertor We see the output and input waveforms using the oscilloscope where the channel A is connected to output of the wall charger and channel B is connected to the output of transformer where we are getting a pulsating DC. The simulation was slowly built up piece by piece to ensure proper simulation of the complete circuit, as well as catch any simulation problems that might be encountered. IV. RESULT AND DISCUSSIONS As the setup starts working on the board, we can see the corresponding actions being performed by the devices kept. The actions are performed depending on the parameters associated with them. We can see below that the simulation is been carried out using LTSpice software. In the simulation snapshot we can see there are three waveforms involved one is the input voltage, second is the output voltage and third is the output current. The V(n001) shown is the input voltage, V(n006) shown is the output voltage, I(R11) is the output current. The output voltage is nearly around 54V and output current is nearly around 2.6A. We can see that the wall charger simulation is shown where multisim simulation software from national instrument is been used. Here we were unable show the Fig 4: Simulation result of AC mains charger __________________________________________________________________________ ISSN (Online): 2347-2820, Volume -1, Issue-2, 2013 56 International Journal of Electrical, Electronics and Computer Systems, (IJEECS) _______________________________________________________________________ [2] A Novel approach to propulsion system of HEV’s, Hema Sai.M, GSrinivas Rao, International Journal for Research and Development in Engineering (IJRDE), Vol.1: Issue.1, June-July 2012 pp- 2637,Vignan University, India. V. CONCLUSION A simple lead acid battery charger system was designed successfully. The implementation and simulation of charging circuit was suitably implemented and designed for driving hybrid two-wheeler vehicle which incorporated two different types of charging methodology for charging a lead-acid battery. The powered battery was later been utilized for driving a BLDC motor which drives the vehicle. To charge the battery the wall charger and solar power is been used, where wall charger is the regular AC mains after suitable rectification the dc output is obtained. And as we know the solar power is directly proportional to the sun’s radiation and the sun radiation is not constant always, so we decided to make use of DC-DC buckboost convertor at the output of solar which can give a constant output voltage and this buck-boost convertor was also implemented. Hybrid technology is the perfect solution to the increasing levels of pollution. It is a very good substitute and replacement for a conventional vehicle. [3] A Comparison of multiple boost configurations for small renewable energy battery storage systems, Taufik, Soeprapto, Satwiko Sidopekso, Mohammad Taufik, Proceeding of International Conference on Sustainable Energy Engineering and Application Inna Garuda Hotel, Yogyakarta, Indonesia 6 – 8 November 2012, ISBN 978-60218167-0-7. [4] Power Electronics System Integration for Electric and Hybrid Vehicles, Martin März, Andreas Schletz, Bernd Eckardt, Sven Egelkraut, Hubert Rauh, Fraunhofer Institute of Integrated Systems and Device Technology, Erlangen, Germany. [5] Recommendations for maximizing battery life in photovoltaic systems, a review of lessons learned, James P. Dunlop and Brian N. Farhi, Proceedings of Forum 2001 Solar Energy: The Power to Choose, April 21-25, 2001 Washington, DC, publication No. FSEC-CR-1137. Future Work: Future vehicles will use aspects of hybrid electric technology to reduce fuel consumption without the use of the hybrid drive train. Regenerative braking can be used to recapture energy and stored to power electrical accessories, such as air conditioning. Shutting down the engine at idle can also be used to reduce fuel consumption and reduce emissions without the addition of a hybrid drive train. In both cases, some of the advantages of hybrid electric technology are gained while additional cost and weight may be limited to the addition of larger batteries and starter motors. Unlike petrol and diesel engines the hybrid system is a technology and still has a lot of room for improvement. In any case this technology further the use of environmental technologies while delivering comforts and driving pleasure. No matter which theory regarding the size of fossil fuels reserves one subscribes to it is certain that someday the reserves will run out. At that point cars will be certain to adopt systems such as hydrogen fuel cells. The hybrid technologies will be indispensable in making that system efficient. [6] Design and Development of Solar Assisted Bicycle, Ajit B. Bachche, N. S. Hanamapure, International Journal of Engineering and Innovative Technology (IJEIT) ,Volume 2, Issue 6, December 2012. [7] Evaluation of the Batteries and Charge Controllers in Small Stand-Alone Photovoltaic Systems, Joseph R. Woodworth, Michael G. Thomas, John W. Stevens, Presented at the 24th IEEE Photovoltaic Specialists Conference, 1994. [8] Development of a universal DC power supply using solar photovoltaic, utility and battery power sources, Joe Oladosu Oni, Bukola Olalekan Bolaji, Journal of Energy in Southern Africa ,Vol 22 No 1, February 2011. [9] Development of a Electrically Inspired Low Emission Microcontroller Based Hybrid Vehicle, Habib Ullah, M., T.S. Gunawan, Sharif M. Raihan and Riza Muhida, American Journal of Applied Sciences 9 (10): 1729-1735, 2012. REFERENCE [1] Hybrid Two-Wheelers for Indian Roads, Mr. Abhijeet Khandagale, Mr. Shrikant Sangludkar (IJAEST) international journal of advanced engineering sciences and technologies vol no. 3, issue no. 1, 050 – 051. [10] Selection of Electric Motor Drives for Electric Vehicles, X. D. Xue, K. W. E. Cheng, and N. C. Cheung, 2008 Australasian Universities Power Engineering Conference (AUPEC'08).  __________________________________________________________________________ ISSN (Online): 2347-2820, Volume -1, Issue-2, 2013 57