In this mechanism, the electric traction motor uses the vehicles momentum to recover energy that would otherwise be lost to the brake discs as heat. Regenerative braking in regenerative braking, the power or energy of the driven machinery which is in kinetic form is returned back to the power supply mains. Braking is the most important part of speed control. Braking methods of 3 phase induction motor electrical.
Pdf analysis of regenerative braking in brushless dc motor. Thanks for reading about electric braking of dc motors. To accomplish recovering electrical energy from mechanical energy a voltage boosting operation is necessary which is causing the current flow from induced voltage due to the mechanical motion to battery. Analysis of regenerative braking in brushless dc motor. Apr 24, 2018 regenerative braking uses an electric vehicles motor as a generator to convert much of the kinetic energy lost when decelerating back into stored energy in the vehicles battery. Pdf regenerative braking applied to a dc motor researchgate. Apr 28, 2018 therefore, regenerative braking is not possible in dc series motor. Paper open access regenerative braking system using pulse. Jun 08, 2018 i am doing my graduation project on fuel consumption using regenrative braking for a hybrid propulsion tractor semitrailer model. There are two methods can be used of regenerative braking for a dc shunt motor. Electric braking is easy and reliable,it can stop the induction motors very quickly. Therefore, regenerative braking is not possible in dc series motor. The main criteria for regenerative braking is that the rotor has to rotate at a speed higher than.
The aim is to replace the traditional friction based braking with a more efficient process. A high performance regenerative drive, is able to switch rapidly from motoring to braking modes while simultaneously controlling the direction of motor rotation. Regenerative braking itself is a mature technology. For motoring operation, the phase angle is always less than the 90. It cannot be assumed that because the motor acts as a generator during regenerative braking the motor and generator efficiencies are equal. Probably you already have it, and just didnt know it. Oct 26, 2016 regenerative braking can be implemented by using the any converter used for electric motor control without needing an extra power circuit. There is a number of different ways to implement regenerative braking in a bldc motor. Dc motor acts as a generator during regenerative braking. Energy efficient electric vehicle using regenerative. The dc bus voltage results for the 3phase mosfet bridge are similar to the rectified 3phase diode circuit. It is braking because it also serves to slow the vehicle. In case of dc shunt motors, armature is disconnected from the supply and a.
Regenerative braking takes place whenever the speed of the motor exceeds the synchronous speed. Moreover, electronic gearshift technology is used with the energyregenerative brake for bldcm 45. This type of braking is possible when the driven load or machinery forces the motor to run at a speed higher than no load speed with a constant excitation. In this case regenerative brakes are blended with dissipative brakes or completely replaced by them. Pdf a topic which is of great interest for researchers in the automotive industry is regenerative braking. Whats the difference between a nonregenerative dc drive. On regenerative braking capability of bldc motor ieee. One drive operates in quadrants i and iv, the other operates in quadrants ii and iii. It is a form of braking in which the kinetic energy of the motor is returned t. This paper describes the independent switching scheme for regenerative braking. When the motor operates in one of these two modes, a regenerative drive can take the electrical energy generated by the motor and feed it back to the ac power source or to a common bus that supplies two or more drives. Regenerative braking of bldc motors by daniel torres, applications engineer. Dec 30, 2018 regenerative braking takes place whenever the speed of the motor exceeds the synchronous speed.
Operation of motor in electric vehicles the principle behind regenerative braking is, when an electric motor runs in. In case of dc series motor an increase in speed is followed by a decrease in the armature current and field flux. Regenerative braking uses an electric vehicles motor as a generator to convert much of the kinetic energy lost when decelerating back into stored energy in the vehicles battery. The motor as a generator can only deliver power to the battery if its terminal voltage exceeds the battery voltage. The regenerative braking is applied to dc shunt motor, series motor and 3phase induction motors. Operation of motor in electric vehicles the principle behind regenerative braking is, when an electric motor runs in one direction, it converts electrical energy into. Driving the bldc motor for one particular motor state.
Aug 06, 2016 when the motor operates in one of these two modes, a regenerative drive can take the electrical energy generated by the motor and feed it back to the ac power source or to a common bus that supplies two or more drives. If no load is there to consume the regenerated power the voltage of the line will increase due to capacitance of line which will definitely damage the insulation. How can i implement regenerative braking of a dc motor. Regenerative braking can improve energy usage efficiency and can prolong the driving distance of electric vehicles evs. Draw the speedtorque characteristics of dc shunt motor and series motor.
It is a form of braking in which the kinetic energy of the motor is returned to the power supply system. In mechanical braking we have disadvantages like heat dissipation, mechanical brakes also depends on the skill of the operator. Simulink model of regenerative braking matlab answers. However, in electric traction, where the regenerative braking of the dc series motor is used, the motors are reconnected as separately excited machines while breaking. Jan 29, 2018 regenerative braking takes place whenever the speed of the motor exceeds the synchronous speed. In the regenerative braking operation, the motor operators as a generator, while it. An experimental set of data published by a us laboratory in 2001 on the efficiency of motors or likewise generators is displayed in fig. Jul 12, 2017 generally, there are 3 types pf electrical braking which can be applied in a dc motor.
Regenerative braking technology captures the energy created by braking process back into the system in the form of charging the battery for further use. Regenerative braking is a system in which the electric motor that normally drives a hybrid or pure electric vehicle is essentially operated in reverse electrically during braking or coasting. Because the additional charge from regenerative braking would cause the voltage of a full battery to rise above a safe level, our motor controller will limit regenerative braking torque in this case. Regenerative braking is an energy recovery mechanism that slows down a moving vehicle or object by converting its kinetic energy into a form that can be either used immediately or stored until needed. In case of dc shunt motors, armature is disconnected from the supply and a rheostat variable resistor is connected across it. One of the most interesting features of electric motors when used in drive train application is that they can also behave as generators, and thus recharge the vehicles battery while braking. First, the electrical circuit and principle are depicted in detail. Regenerative braking is an effective way to extend the driving range of a battery electric vehicle bev. Energy efficient electric vehicle using regenerative braking. Kinetic energy bldc hub motor used in ebike application while braking, energy is stored in the battery regenerative braking stores energy back into the battery, while increasing the life of friction pads on brake shoe. A new electric braking system with energy regeneration for.
Regeneration is possible in dc series motor since the field current cannot be made greater than the armature current. The rbs is adapted to brushless dc bldc motor, and it emphasizes on the distribution of the braking force, as well as bldc motor control. Paper open access regenerative braking system using. It should always be ensured that load is available for consuming the regenerated power. Regenerative braking of bldc motors microchip technology. Hence if you want to brake dc motor, you have to convert its kinetic energy in to other forms of energy, for e. To generate 24volts from the motor or higher voltage, the motor should run at a speed of 3,400 rpm or higher. Whats the difference between a nonregenerative dc drive and. In this type of braking, the dc motor is disconnected from the supply and a braking resistor r b is. Therefore, regenerative braking is not possible with ordinary dc series motor. Roboteqs motor controllers can easily be programmed to take advantage of this characteristic to create regenerative braking in a controlled and progressive manner. This type of braking is possible when the driven load forces the motor to run at a speed higher than its noload speed with a constant excitation.
Braking methods of 3 phase induction motor electrical edition. As a consequence of the motor, the kinetic energy is converted into electrical energy and back to the supply. Energy storage system for effective use of regenerative. Regenerative braking is a unique technique that is used in evs to capture energy that the vehicle has due to its motion or, in other words, its kinetic energy that would have been wasted when the vehicle decelerates or comes to a standstill while braking. Different electrical braking scheme kinetic energy kinetic energy dynamic braking or regenerative braking. Regenerative braking has a similar energy equation to the equation for the mechanical flywheel. The back emf eb cannot be greater than the supply voltage. The process of regenerative braking is shown by the arm.
The machine now begins to operate as a generator and the energy generated is supplied to the source. In a batterypowered electric vehicle, regenerative braking also called regen is the conversion of the vehicles kinetic energy into chemical energy stored in the battery, where it can be used later to drive the vehicle. The input power of the induction motor drive is given by the formula shown below. When the induction motor runs above the synchronous speed, relative speed between the conductors and air gap rotating field reverses, as a result the phase angle because greater than 90 rotor produces torque in opposite direction to achieve the braking thus regenerative braking takes place. Regenerative braking is one of the methods to increase the range by charging the battery from the energy available during braking. Aug 22, 2018 it is very interesting to note that regenerative braking cannot be used to stop a motor but to control its speed above the noload speed of the motor driving the descending loads. During regenerative braking, the vehicle inertia together with power electronic converters makes the motor to act as the generator to send the energy back to the battery. The fig above shows that the regenerative braking of a dc shunt motor. This baking method is called regenerative baking because here the motor works as a generator and. Regenerative braking can be implemented by using the any converter used for electric motor control without needing an extra power circuit.
Aim of this project is to understand the basic thinks and also understand the control and breaking of dc motor. Regenerative braking makes electric vehicles more suitable for everyday use and reduces fuel consumption and emissions of co 2 and other pollutants, particularly in urban traffic situations involving frequent braking and acceleration on hybrid vehicles. Electrical braking system types, requirements, advantages. In order to effectively exploit the potential of brake energy recovery in dc systems, additional technologies can be implemented onboard or in substations. This paper describes an optimal regenerative braking control scheme for a permanent magnet brushless dc motor to achieve goals of the electric brake with energy regeneration. So we go for electrical braking on induction motor. Regenerative braking is a twostep process involving the motor generator and the battery. Analysis of regenerative braking in brushless dc motor drive. Plugging, regenerative braking of dc motor my tech info. A topic which is of great interest for researchers in the automotive industry is regenerative braking.
Lets consider a halfbridge, since for this analysis we will run the motor in only one direction. Regenerative braking of brushless dc motor semantic scholar. A common bus provides additional energy savings in that the power is only converted from ac to dc one time. This was inspired by phil frosts post on the electronic. Hence we have to figure out ways to boost the back emf generated by the motor so that even at lower speeds, the motor can work as brake. If you are driving a motor with a halfbridge or hbridge and pwm or similar, you have regenerative braking. This baking method is called regenerative baking because here the motor works as generator and supply itself is given power from the load, i. Thus the regenerative braking is better than plugging and dynamic braking. At the same time motor braking torque is applied to. In most studies on the choppercontrolled re generative braking of the dc motor l101.
A regenerative dc drive is essentially two coordinated dc drives integrated within a common package. Under this condition, the back emf eb of the motor is greater than the supply voltage v, which reverses the direction of. The energy recovered can be utilized for improving the acceleration of the vehicle. It is very interesting to note that regenerative braking cannot be used to stop a motor but to control its speed above the noload speed of the motor driving the descending loads. In braking, the motor works as a generator developing a negative torque which opposes the motion the braking is mainly classified into three types i. The initial kinetic energy is transformed into electrical energy by the generator and is then converted into chemical energy by the battery. I am trying to establish the model for the combination of a vehicle with diesel engine with an in wheel electric motor for brake energy regeneration.
Generally, there are 3 types pf electrical braking which can be applied in a dc motor. Electric braking of dc motors your electrical guide. This type of braking is used in traction whenever the train runs on down. Since this motor is rated for 24volts, the battery terminal voltage would be 24volts. In addition, using the motorgenerator for braking reduces brake wear and the buildup of. It is regenerative because the energy is recaptured in the battery where it can be used again. Regenerative braking it is a form of braking in which the kinetic energy of the motor is returned to the power supply system.
Jan, 2017 using a simple model for a dc motor, lets figure out how to use its momentum to recharge a battery. In an electric vehicle, regenerative breaking helps to conserve energy by charging the battery, thus extending the driving range of the vehicle. Regenerative braking is necessarily limited when the batteries are fully charged. Instead of consuming energy to propel a vehicle, the motor acts as a generator that charges the onboard batteries with electrical energy that would normally be lost as heat through traditional. Unfortunately, these methods need an additional dcdc converter to reach the purpose has the efficiency problem that results in additional energy dissipation. During the braking period, the proposed method only changes the switching sequence of the inverter to control the inverse torque so that the braking energy will return to the battery. Regenerative braking of the separately excited dc motor via chopper. What are regenerative drives and where are they used. Pulses for controlling both motoring and regenerative braking actions are generated following the operating principles of brushless dc motor in these two modes. Pdf analysis of regenerative braking in brushless dc.
Using a simple model for a dc motor, lets figure out how to use its momentum to recharge a battery. Regenerative braking in an electric vehicle, cody et. The fieldwinding connections for shunt motors are left undisturbed. This article describes the theory behind a simple and very effective technique that uses the motor speed sensing. Regenerative braking an overview sciencedirect topics. Energy storage system for effective use of regenerative energy in electrified railways 34 2 regenerative brake with effective speed extended function hitachi has developed the regenerative brake with effective speed extended function as a solution to the problem of limits on performance due to motor characteristics. A creative regenerative braking system rbs is presented in this paper. The higher the motor power and the more axles are powered, the more energy may be recovered. Regenerative braking boundaries and maximum regenerative braking current curve.
The magic of tesla roadster regenerative braking tesla. Through this research a method of recovering energy through braking was developed. The braking is the process of reducing the speed of an induction motor. The regenerative braking of a dc motor is very useful for saving energy. Regenerative braking system of electric vehicle driven by. I am doing my graduation project on fuel consumption using regenrative braking for a hybrid propulsion tractor semitrailer model. This technique can also be used to totally eliminate regenerative braking if needed. Under this condition, the back emf e b of the motor is greater than the supply voltage v, which reverses the direction of motor armature current. On brushed dc motor, speed can be sensed using an optical. Numerical optimization solutions for permanent magnet dc machine. The electric braking of a dc motor is of three types, i rheostatic or dynamic braking, ii plugging or reverse current braking and iii regenerative beaking. Law of energy conservation says, energy can not be created or destroyed.
404 803 451 177 313 79 1306 367 859 609 423 863 24 1025 224 499 760 380 1149 805 613 347 699 1142 1071 1346 942 281 743 830 1174 223 125 29 378 1350 512 575