Lecture 30 speed control of induction motor part 1. Speed control of induction motor using pwm technique. N sandhya rani3 1mtech student department of electrical engineering, griet, hyderabad500072 2assoc professor in the department of electrical engineering, griet, hyderabad500072. The speed torque curve of an induction motor can be modified by an armature winding reconnected to give different sets of poles.
When only main induction motor work, having speed corresponds to. Induction machines guru nanak dev engineering college. However, recently, it has been increasingly used as variable speed motors driven by an inverter. Induction motor performance is checked through the simulation studies in matlabsimulink environment. The difference in speed between rotor, the synchronous speed and the rotating. Find the percentage slip and number of poles of the induction motor. Hence only details of scalar methods are discussed here. The different methods of speed control of im can be broadly classified into scalar and vector control methods. Induction motor seminar ppt, pdf report study mafia. Speed control of a three phase induction motor using pwm. So obviously the speed of an induction motor can be controlled by varying any of three factors namely supply frequency f, number of pole p or slip s.
So, we were discussing about the problem of starting large induction motor from direct full voltage supply. Speed control of induction motor part 1 by, supply. Free download induction motor seminar ppt, pdf report. Before discussing, induction motor drives its important to understand and know about induction motors. Different speed control methods of induction motor are explained below. A three phase induction motor is mostly a constant speed motor so its fairly not easy to control its speed. Simulation of speed control of induction motor using vf.
When cumulative cascading is done, then the complete set runs at a speed of. From the equation 1 it is clear that the motor speed can be changed by a change in frequency f, a number of poles p, and slip s. Firstly threephase induction motor drive system is simulated in various modes using matlabxilinx, then finally closed loop control of induction motor is. A 3phase induction motor uses current delivered in three phases in a sequence into the coils of a stator to create a rotating magnetic field. The main methods employed for speed control of induction motors are as follows. The synchronous motor either run at synchronous speed or it will not run. This method of controlling the speed by pole changing is used mainly for cage motor only because the cage rotor automatically develops a number of poles, which is. Therefore the efficiency of three phase induction motor is reduced by this method of speed control.
In the reference 3 different types of pwm strategies have been used for speed control of induction motor drive. The operating point is the intersection of the two characteristics and we can fix for a given load and motor. In very simple words induction motors can be described as a threephase, selfstarting constant speed ac motors. This course is suitable for anyone interested in learning about induction motors. The present course advanced electric drives focuses on the dynamic control of dc and ac motor from solid state converters for better torque and speed response. Mras for speed control of the induction motor drive. Induction motor drives starting braking speed control of.
The role of cycloconverter in speed control of induction motor is to vary the supply frequency which in turn, changes the speed of motor. Self controlled synchronous motor, unity power factor operation, vector control of synchronous motor, cycloconverterfed synchronous motor drive. An induction motor can be defined as the ac electric motor device in which a power source fed by the alternating current with the help of a primary winding. This paper presents a modified fuzzy control for speed control of induction motor im. In this video i describe about the speed control of inductuon motor by using different methods like, 1. Speed control of induction motors using matlab udemy. The first is the flux and torque producing currents. It supplies an induction motor ich has a full load speed of 144wh 0 rpm. Hybrid speed control of induction motor using pi and fuzzy. Besides increasing the range of speed control, the current drawn by the motor at low voltages can be limited by a proper choice of rotor resistance. This induces an electric field in a coil or squirrel cage to drive a rotor. The previous control strategies good steadystate but poor dynamic response oscillation resulted from the air gap flux vector control fieldoriented control is related to the phasor control of the rotor flux. When the speed control of three phase induction motor is done by adding resistance in rotor circuit, some part of power called, the slip power is lost as i 2 r losses.
Starting of 3 phase induction motors, high starting torque motors, speed control, rheostatic method, pole changing method. The user can quickly start evaluating the performance of the vhz system with this method. It is a 16 bit highperformance digital signal controller dsc. Pdf induction motors im are widely used in the industrial application due to a high powerweight ratio, high reliability and low cost. The speed of a threephase induction motor driving a given load is determined by matching the torque speed characteristics of the motor and load, as shown in fig. The efficient and essential step to control the speed of an induction motor, is to control the frequency of the supply. As the torque at zero rotor speed is nonzero, the induction motor is selfstarting. The reason for describing induction motors as constant speed is because normally these motors have a constant speed depending on the frequency of the supply and the. Actual speed of an induction motor is given as n ns 1 s. So, therefore, in an induction motor the ladder is enclose upon itself. Synchronous speed is directly proportinal to frequency,similar ti induction motors constant flux operation below base speed is achiecved by operating the synchronous motor with constant v f ratio. Torque speed characteristics of induction motor slip. By using pwm strategies, in the reference 45 inverter is used to drive the speed of induction motor, ac choppers are used in the reference67 for the speed control of induction motor. More than 90% of motors used in industries are squirrel cage induction motor due to its rugged and maintenance free design.
Vf speed control of 3 phase induction motor using space. The electric motor speed is fixed when ac motor is connected to ac line. At first, the pi controller is investigated for speed control of induction motor, and then fuzzy logic controller performance is simulated. A case study the simulation results of a vector control system with induction motor based.
The synchronous motor either run at synchronous speed or it will not run at all. Variable voltage variable frequency control of threephase induction motor in closed loop is the significant feature of the thesis work. Introduction this application note describes the design of a 3phase ac induction motor drive with volts per hertz control in closedloop vhz cl. Therefore, the need of speed control methods for induction motor arises. There are more than one methods to control the speed of induction motor, you can choose one depending on your resources, efficiency required etc. Pole changing method pole changing method is one of the main methods of the speed control of an induction motor. Gopakumar, centre for electronics design and technology, iisc bangalore. The strategy used is a modified field oriented control to control. How to control the speed of an induction motor quora.
If you want to control induction motor speed, save yourself a lot of grief and get a 3phase motor. As induction motors are widely being used, their speed control may be required in many applications. Sometimes theyre talking about induction motors, other times not, and they dont specify which is which, or even which induction motor type they are talking about. Generally an induction motor operates at almost constant speed as the load is varied. There are various methods of speed control for an induction motor. Before discussing the methods to control the speed of three phase induction motor one should know the necessary formulas of speed. Synchronous speed of the rotating magnetic field of an induction motor is given by, where, f frequency of the supply and p number of stator poles. Mainly due to power electronics and digital control, the induction motor. Speed control of three phase induction motor electrical4u. Right from its inception its ease of manufacture and its robustness have made it a very strong candidate for electromechanical energy conversion.
For example, if it is a wound rotor induction motor you can vary the speed by varying the rotor resistance or you could vary the supply voltage alone, that is you can. The explanation of vector control method is beyond the scope of this thesis. Speed estimation is an issue of particular interest with induction motor drives where the mechanical speed of the rotor is generally different from the speed of the revolving magnetic field. Suppose, there is a load torque, full load torque it will be in between this about 5 percent. Vector control offers a number of benefits including speed control over a wide range, precise speed regulation, fast dynamic response, and operation above base speed. Hence, the synchronous speed changes with change in supply frequency. The previous control strategies good steadystate but poor. In vf speed control technique vf ratio is to be kept constant so that flux remains constant.
Speed control of single phase induction motor using ac. A theoretical background on scalar motor control principle. Generally, it is known as the asynchronous motor because its running speed is less than its synchronous speed. Idea of vvvf speed control of induction motor nptel. In this paper, speed control of induction motor using cycloconverter is presented. The rotor speed of an induction motor is given by the equation shown below. This paper presents design and analysis of a three phase induction motor drive using igbt. Speed control of induction motors the speed of an induction motor is given as n 120fp 1s. Induction machines 1 introduction the induction machine was invented by nikola tesla in 1888. So, anyway this is the induction motor speed and motor operates in this table zone this is almost a linear portion and we have discussed that. Pdf speed control of induction motor using pi and vf. The vector control algorithm is based on two fundamental ideas. It is based on freescales 56f800e microcontrollers. Speed control of induction motor by using cycloconverter.
It is hard to learn anything valueable from that page. At the end of the course you will understand all of the fundamentals of speed and torque control of induction motor and understand how to create its performance curve successfully using matlab. Variable voltage variable frequency speed control of. Lecture 30 speed control of induction motor part 1 youtube. Introduction to single phase induction motor nptel. Induction motors have been traditionally used as constant speed motors supplied by the ac power source. A sliding mode control smc with integral surface is employed to control the speed of threephase induction motor in this paper. In the present work, the simulation of speed control of motor at different. The different methods of speed control of induction motor can be broadly classified in to scalar and vector control methods. Speed control of induction motor using arduino sakina tabassum1, syed sarfaraz nawaz2 and m. Speed control of induction motor 7 ways to control. Methods of speed control of induction motor electrical. Speed control of induction motor using cycloconverter.
This is now explained using double field revolving theory. So, first speed control of induction motor various methods which were earlier used, no point in discussing in detail, but i will give you definitely the idea. Out of all the electrical machines, induction motor is the most used machine in industries. When only auxiliary induction motor work, having speed corresponds to. Starting methods for singlephase induction motor nptel. Ac induction motor speed control so what can we do to control the speed of an ac induction motor. Speed control of an induction motor there is a various method of speed control of an induction motor. In this system, the scalar control vhz of induction motor experiments with and explores the use of speed control. The speed control of induction motor is done at the price of reduce in efficiency and low power factor. A three phase, 12 pole, salient pole alternator is coupled to a diesel engine running at 500 rpm. In this method of speed control of three phase induction motor, four different speeds can be obtained. In this model, simulation of speed control of induction motor is done using vf method with the implementation of sinusoidal pulse width modulated signals fed to the inverter.
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