Jan 09, 2017 this method is applicable to squirrel cage induction motor only. It is widely used in industry due to low cost and rugged construction. Ahuja speed control of induction motor using vector or field oriented control international journal. The motor in which the provision of changing the number of poles is present, they are called pole changing motor or multi speed motor. Jun 05, 2018 in this method, the slip power of induction motor is utilized for speed control. Speed control of single phase ac induction motor possible. Changing the frequency of power supply is a economical speed regulation method, and it is also one of most popular ways of induction motor speed control. The synchronous speed and therefore, the speed of the motor can be controlled by varying the supply frequency. Slip power in induction motor is the power dissipated in the rotor winding as ohmic loss. Speed control of induction motor using vf technique phase i a thesis submitted in partial fulfillment of the requirements for the degree of bachelor of. Three phase induction motor induction is one of the widest spread motor due to its robustness, simple construction, no need for complex circuits for starting. Speed control of single phase induction motor using ac. Jul 12, 2017 in ac rotating machine speed of machine is govern by the equation n120fp.
In this paper, a new method of speed control for the single phase induction motor is introduced to overcome the disadvantages of the conventional methods. Speed control of an induction motor there is a various method of speed control of an induction motor. Record all nameplate information for the induction motor. A digital phase locked loop speed control of three phase. Speed control of three induction motor by vf method for batching motion system. Since motor parameters are required to estimate speed and sometimes it is impractical to do noload and locked rotor tests, it is necessary to estimate motor parameters from. Speed control of three phase induction motor electrical. The three phase induction motor has following advantages. Dec 17, 2019 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. Speed control in three phase induction motor mcqs with. The motor is mounted in a test rig that allows one to control the torque applied to the motor shaft and to measure both rpm and torque. Different method of speed control a three phase induction motor is mostly a constant speed motor so its fairly not easy to control its speed. However, asynchronous motors do not inherently have the capability of variable speed operation. Adding an external resistant into rotor side circuit.
In this method, the magnitude of the main winding current and its angle are controlled to control the motor speed, as well as to increase the starting torque at all speed settings. Speed control of induction motor using pwm technique. Speed control of three phase induction motor electrical4u. Methods of speed control of induction motor electrical. The simulation results show that the step response of the model is very fast, steady and able to work in four quadrants, and robustness and. An induction motor is practically a constant speed motor, that means, for the entire loading range, change in speed of the motor is quite small. Speed control methods of dc motor shunt, series motors. The main challenge is based on robustness and low cost. Speed control of a three phase induction motor using. Asynchronous motors are the most widely used electrical motors due to their reliability, low cost, ruggedness and robustness. Speed control methods of various types of speed control. Other methods use ac chopper with pulse width modulation pwm technique to control the applied voltage of the motor 24. Thus in this paper, ac chopper is implemented to control the speed of single phase induction motor by using 3 asymmetrical pwm method.
Digital phase locked loop dpll, induction motor, scalar strategy, speed drives and load appliance. Why is speed control in an induction motor, difficult. The method which can be used for the speed control of induction motor from stator side is a. Various induction motor speed control methods advantages. Speed control of induction motor using vector control technique.
This method is also called the tandem control and obsolete now. Different methods of speed control of threephase asynchronous. The ac speed control motor unit that uses the most popular singlephase capacitorrun induction motor, the small and highly efficient brushless dc motor unit. Paper open access speed control of 3phase induction. Before discussing the methods to control the speed of three phase induction motor one should know the basic formulas of speed and torque of three phase. This paper describes a simplified method for the speed control of a three phase ac drive using proportionalintegral controller. As we know that, air gap power p g is sum of mechanical power output and power loss in rotor winding assuming rotor winding to be shorted. Variable frequency speed control is a way to change the power frequency of motor stator and then change its synchronous speed. Speed control of induction motor by variable frequency control. You should also make a dc measurement of stator winding linetoline resistance using a dmm. Speed control of an induction motor by using indirect vector. Pdf speed control of three phase induction motor using. So for varying the speed of the 3 phase induction motor we have to vary the ns.
Pdf speed control of induction motors kamakhya basumatary. Pdf speed control of induction motor using foc method. Speed control of induction motor detailed explanation. Matlab simulation of the proposed speed control method for 1hp induction motor was done to verify the performance of the proposed method.
Low cost, low maintenance, simple construction, reliability and high efficiency. Rotorresistance speed control similar to rotorresistance starting, this method consists of varying the effective resistance in the rotor of a woundrotor induction motor to vary the speed. Before discussing the methods to control the speed of three phase induction motor one should know the basic formulas of speed and torque of. While researching on the internet i came across this one circuit that proposes a model that uses a microcontroller and a triac circuit and a. With several available speed control techniques, this paper presents a new. The speed control of induction motor is done at the cost of decrease in efficiency and low electrical power factor. Microcontroller based control of three phase induction motor using pwm technique. There are more than one methods to control the speed of induction motor, you can choose one depending on your resources, efficiency required etc. The speed of induction motor can be varied by changing supply voltage.
The performance of the motor speed control required in. Pdf the applications of induction motors in various fields are increasing day by day because of the robustness and low maintenance cost. Speed control of three phase squirrel cage induction motor using vf method is implemented. Variants of this method include rotor power recovery systems using a second machine or. New method for speed control of single phase induction motor. 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. As we know that, air gap power p g is sum of mechanical power output and power. Speed control of wound rotor induction motor using rotor resistance control aim to use variable resistance in the rotor circuit to control wound rotor induction motor speed theory polyphase induction motors are mainly of two types by construction, squirrel cage and woundrotorwith sliprings. February 5, 2002 have been shown to be more than a match for dc drives in highperformance applications. As in above method, if the supply frequency is reduced keeping the rated supply voltage, the air gap flux will tend to saturate. This slip power loss can be recovered and supplied back to improve the overall. While control of the induction machine is considerably more complicated than its dc motor counterpart, with continual advancement of microelectronics, these control complexities have essentially been.
Model is developed for spwm inverter fed induction motor using xilinx. Various methods are 3 magnetizing flux oriented control used to control the. Controlling number of stator poles to control n s c. Jun 30, 2015 a three phase induction motor is basically a constant speed motor. Currently the use of threephase induction machines has been increased tremendously in industrial applications due to several methods available to control the speed and torque of the motor. A common method of controlling the stator voltage is by use phase angle control of thyristor circuit inserted in series between the supply and motor.
Dec 23, 2017 the speed control of induction motor by considering to control on rotor side can subdivide into several speed controlling methods such as. Variable voltage variable frequency speed control of. A 3 phase induction motor can be used for different applications with various speed and load requirements. The speed control of the induction motor can be done by the stator as well as rotor end. Speed control methods of the various speed control motors. However, present trends and increase of speed control methods of an induction motor have improved the use of induction motors in electrical drives broadly. A theoretical background on scalar motor control principle. The salient features of stator voltage control method are. This paper presents the design of a xilinx field programmable gate array fpga based sinusoidal pulse width modulation spwm for a threephase voltage source inverter vsi with variable voltage variable frequency vvvf for controlling the speed. The implementation is done using a rectifier and an inverter, where the pwm triggering pulses were generated by using pic micro controller for switching the igbts of the inverter.
Speed control of an induction motor by using indirect. Ims are used in many industry sectors as the leading element to convert electrical energy into mechanical one. Another method of controlling the speed of induction motor drives is the stator voltage control. Open loop control of induction motor im is used in this inverter scheme. However, it is expensive and destroys the mechanical robustness of the induction motor. A three phase induction motor is basically a constant speed motor so its somewhat difficult to control its speed. In this system, the scalar control vhz of induction motor experiments with and explores the use of speed control.
Conventional methods for starting and speed control of singlephase induction motor need often quite expensive external electrical equipment. There are two ways of speed control for a dc motor, field control in this method, the eld current or current through stator is varied to control the speed of. Methods of speed control of induction motor electrical concepts. Since the number of pole pairs can only be changed in steps like from 2 to 4, this scheme provides stepped speed control of induction motor. This enables to analyze and calculate the different parameters like voltage and current in different parts of the converter and performance of. Pdf induction motors do not run at synchronous speed, they are generally fixed speed motors. Speed control of induction motor using vector control. This method is applicable to squirrel cage induction motor only.
Speed control methods of various types of speed control motors. The synchronous speed of an induction motor is given by the relation shown below. New method for speed control of single phase induction. The different methods of speed control of induction motor can be broadly classified in to scalar and vector control methods. Therefore the efficiency of three phase induction motor is reduced by this method of speed control. Stator voltage is directly responsible for the rotating speed of the rotor. A sliding mode control smc with integral surface is employed to control the speed of threephase induction motor in this paper. Induction motor is a fixed speed motor and its fixed speed is nearly equal to the synchronous speed that is the speed of rotating magnetic field. Pdf speed control of induction motor using pi and vf. How to control the speed of an induction motor quora. Speed control of induction motor by variable frequency control variable frequency control is a method which is used to control the speed of an induction motor.
The analysis has been done in terms of thd in their line current. Ns can be varied by varying the factor on which it depends upon i. There are following methods of speed control of three phase induction motor. The speed control of induction motor by considering to control on rotor side can subdivide into several speed controlling methods such as. Variants of this method include rotor power recovery systems using a second machine or an auxiliary solidstate rectifier and converter.
But the recent developments in speed control methods of the asynchronous motor have led. Speed control of three phase squirrel cage induction motor. In ac rotating machine speed of machine is govern by the equation n120fp. Speed of a dc shunt motor can be varied very easily with good efficiency, but in case of induction motors, speed reduction is accompanied by a corresponding loss of efficiency and poor power factor. The torque developed in this method is proportional to the square of the supply voltage. In the simulation all realistic components of the drive system has been included. An increasing number of applications in high performing electrical drive systems use nowadays, squirrelcage induction motors. Speed control in three phase induction motor mcqs with answers q1.
The user can quickly start evaluating the performance of the vhz system with this method. In this method, the slip power of induction motor is utilized for speed control. The rotor speed of an induction motor is given by the equation shown below. Speed control of wound rotor induction motor using rotor. In this paper, various methods of speed control of induction asynchronous motors such as variable rotor resistance, variable stator voltage, constant voltshertz. The output control method of a speed control circuit can be divided roughly into two groups. An introduction there are various methods for the speed control of an induction motor.
As we know the speed of induction motor, torque of induction motor, so, the speed of induction motor can be changed by changing synchronous speed or by changing the slip of induction motor and then parameter r2 and x2 are changed then torque remain constant and change in slip is affected in speed control. Hi all, so im working on a project titled controlling the speed of a single phase induction motor. Due to this reason, earlier dc motors were applied in most of the electrical drives. A three phase induction motor is basically a constant speed motor. To improve speed control performance of the scalar control method, an encoder or speed tachometer is required to feedback the rotor angle or rotor speed signal and compensate the slip frequency. Induction motor drives starting braking speed control of.
Matlab simulation for speed control of three phase. The most popular type is the 3phase, squirrelcage ac induction motor. The strategy used is a modified field oriented control to control. The pmdc consists of rotor or armature and a stator, which is a permanent magnet. Speed control of a three phase induction motor using pwm. Pole changing method speed control of induction motor. Induction motor, mathematical model, voltperhertz controller, control, matlab simulink. In pole changing method, the number of pole pairs is changed by changing the field connection. Constant vf control of induction motor this is the most popular method for controlling the speed of an induction motor. Thus it is obvious that to change speed of machine any one parameter either frequency or no of poles are to be changed. There are three method to control the speed of induction motor by the stator end.
159 561 1460 223 1347 28 871 1497 316 104 652 1146 361 509 531 1428 450 401 1161 363 192 1491 131 1494 343 1175 1086 1377 293 620 881 208 1025 413