This paper is aimed to give a contribution for a detailed comparison between the two control techniques, emphasizing advantages. The various methods of speed control of squirrel cage im through semiconductor devices are given in 2, 920 as under. Nov 27, 2019 field oriented control describes the way in which the control of torque and speed are directly based on the electromagnetic state of the motor, similar to a dc motor. Electrical study of the dc motor shows that the produced torque. Direct torque control concept direct torque control has its roots in fieldoriented control and direct self control. This thesis obtains the modelling of the direct torque control dtc system of pmsm using matlabsimulink. Control loop of an ac drive using dtc controlling variables with the revolutionary dtc technology developed by abb, field orientation is achieved without feedback using advanced motor theory to calculate the motor torque directly and without using. Control loop of a dc motor drive features field orientation via mechanical commutator controlling variables are armature current and field current, measured directly from the motor. Refer to the description of force technology on the following page. With decoupling between the stator current components magnetizing flux and torque, the torque producing component of the stator. Field oriented control of pmsm drives is becoming more popular especially in. Conventional direct fieldoriented control dfoc algorithms provide more precision for torque control than scalar schemes, but require sensors for the speed control of the rotor and the magnetic flux to provide the data for the foc algorithms.
Vector control of pm synchronous motor drive system using. Direct torque control electrical engineering portal. The field oriented control foc is a kind of usual control method for ac servo motor. Nov 28, 2018 learn how field oriented control provides highperformance torque or speed control for various motor types, including induction motor, permanent magnet synchronous machines pmsms, and brushless. Field oriented control foc and direct torque control dtc. Fieldoriented control and direct torque control for. Field oriented control, direct torque control and model. Essentially, there are two components of current in the st.
Abstract this paper presents a comparative study of fieldoriented control ifoc and directtorque control dtc of induction motors using an adaptive flux observer. Direct torque control dtc 4 and direct self control dsc 5. Field oriented control what distinguishes a product using field oriented control from a traditional vector product is its ability to separate and independently control or regulate the motor flux and torque. Direct the motor torque is proportional to the armture current. The control system of the drive calculates the corresponding. Difference between field oriented control and direct. In field oriented control method, the components of the motor stator. In order to understand the spirit of the field oriented control technique, let us start with an overview of the separately excited direct current dc motor. Design and simulation of field oriented control and direct. This paper presents a comparative study on two most popular control strategies for permanent magnet synchronous motor pmsm drives. Even though the torque generated is less when compared to bldc motors, pmsm generates less torque ripples.
Vector control and direct torque control of induction motor using matlab simulink submitted by fathalla eldali department of electrical and computer engineering for the degree of master of science colorado state university fall 2012 1. The effect of voltage sags and short interruption on driven induction. In the rotorfixed frame the voltages and currents are nearly static, slowly timevarying quantities. Its based on converting the threephase currents of the stator into two orthogonal components i. The choice of direct torque control from these methods gives advantages such as. Noguchi 1 as a new performant control strategy for induction motor drives fed by voltage source inverters vsi. Abstract this paper presents a comparative study of field oriented control ifoc and direct torque control dtc of induction motors using an adaptive flux observer. Torque control is required in a control range greater than 1. Comparison of sensor and sensorless vector control.
Foc is therefore used in high performance drives where oscillations in air gap flux linkages are intolerable, e. Foc is the first technology to control the real motor control variables of torque and flux. Notice that in the definition of field oriented control we. Generally foc consists of the following components. Secondly, the direct torque control dtc for the paralleled vsis fed pmsm drive is. There are other wellknown methods like direct torque control and direct selfcontrol that work with vectors, as well. Field oriented control is based on a mathematical abstraction. The comparison of field oriented control and direct torque control methods conference paper pdf available april 2011 with 449 reads how we measure reads. Foc and direct torque control dtc of the permanent magnet synchronous pms motor. Foc uses linear controllers and pulse width modulation pwm. Dtc is direct torque control, a method used by abb in their highperformance drives. Fieldoriented control uses spatial vector theory to optimally control magnetic field orientation. Vf control, field oriented control, and direct torque control.
Direct torque control or dtc is the most advanced ac drive technology developed by any manufacturer in the world this manuals purpose. Speed control of pmsm using field oriented control technique and direct. This method was born in parallel with two different names. Simulation, analysis and comparison of fieldoriented control and direct torque control 6 this means that the electromagnetic torque is the function of three parameters. One component defines the magnetic flux of the motor, the other the torque. The main characteristics of fieldoriented control and direct torque control schemes are studied by simulation, emphasizing their advantages and disadvantages. It is function of the frontal area shape protrusion such as side, mirrors, ducts and air passages spoilers and any other factor. Pdf the comparison of field oriented control and direct. Pdf field oriented control foc and direct torque control dtc are the two most. Comparison of fieldoriented control and direct torque. Direct torque control versus indirect fieldoriented. It has been successfully applied to the design of flux vector controls and is well documented. Both foc and dtc are based on the decoupling between the current components used for generating magnetizing flux and torque 5.
The field oriented control ensures good and robust control in case of transients. The vector control technique decouples the two components of stator current space vector. Comparison of direct and indirect vector control of. Field oriented control foc, direct torque control dtc and. A comparative study on field oriented control and direct. Comparison between field oriented control of bldcm and.
Indirect field oriented control the ifoc is a highperformance method used to control the ims by controlling the stator currents. The study is done by simulation using the simulink power system. Difference between field oriented control and direct torque. What is the difference between vector control and dtc. Field oriented control foc and direct torque control dtc are the two most popular vector control methods for electric motor drives. Abstract fieldoriented control and direct torque control are becoming the industrial standards for induction motors torque control. The pmsm control is equivalent to that of the dc motor by a decoupling control known as field oriented control or vector control. A comparative study of fieldoriented control and direct. Control loop of a dc motor drive features field orientation via mechanical commutator controlling variables are armature current and field current, measured directly from the motor torque control is direct. There are other wellknown methods like direct torque control and direct self control that work with vectors, as well. Its operation is based on the equation of the developed electromagnetic torque of the motor. Vector control field oriented control, direct torque control. Direct torque control, permanent magnet synchronous motor, space vector modulation 1 introduction direct torque control was introduced by i.
Speed control of pmsm using field oriented control technique and direct torque space vector pulse width modulation technique is also analysed and compared with traditional dtc. Srinu naik abstractvector control is becoming the industrial standard for induction motor control. Learn how fieldoriented control provides highperformance torque or speed control for various motor types, including induction motor, permanent magnet. The efficiency of direct torque control for electric vehicle behavior improvement 1 2. Speed control of a three phase induction motor using field. Field oriented control of pmsm drives is becoming more popular especially in high precision applications. Vector control is a generic term, while dtc is specific in how the vector control is performed. Through the results obtained from schemas showing that both methods are very close in relation to the torque and the response speed to the tracking of the reference imposed by us, and we have observed that the d. Analytical comparison between the performances of field. Direct torque control an overview sciencedirect topics. A detailed comparison between foc and dtc methods of a. Direct torque control dtc is one method used in variable frequency drives to control the torque and thus finally the speed of threephase ac electric motors.
Therefore it is more suitable for the comparison to consider a direct field oriented control dfoc scheme, instead of a general foc scheme. Nov 24, 20 torque control is required in a control range greater than 1. Theoretical comparison vector control and direct torque control. Simplified indirect foc field oriented control describes the way in which the control of torque and speed are directly based on the electromagnetic state of the motor, similar to a dc motor. Later in mid 80s a new vc method appeared to become an alternative to foc.
Pdf comparison of field oriented control and direct. Where sinusoidal commutation is based on a threephase system that is dependent on time and speed, field oriented control transforms this system into a two coordinate systemd and qthat is not dependent on time, similar to that of dc control. The decoupling allows the induction motor to be controlled as. Direct torque control of permanent magnet synchronous.
Field oriented control describes the way in which the control of torque and speed are directly based on the electromagnetic state of the motor, similar to a dc motor. Field oriented control following the standard argument, the foc algorithm is obtained as follows. Subsequent improvements in processor computational power, application programming, and communication interfaces have continually enabled higher dtc performance, providing premium motor control for a broad range of applications. Comparison between direct and indirect field oriented. Direct torque control of three phase induction motor using. According to the multivariable, nonlinearity and strong coupling of pmlsm, the field oriented control converts the stator. These two strategies can be considered among the family of vector control vc methods and provide a solution for highperformance drives. Field oriented control is the first and most popular vector control method 24. Foc uses linear controllers and pulse width modulation pwm to control the fundamental components of the load voltage. They are thus much easier to control than the fast timevarying signals in the statorfixed frame, since a lower controller bandwidth is acceptable. Simulation, analysis and comparison of field oriented. The vector control separates the torque component of current and flux channels in the motor through its stator excitation.
Vector control, also called field oriented control foc, is a variablefrequency drive vfd control method in which the stator currents of a threephase ac electric motor are identified as two orthogonal components that can be visualized with a vector. Download limit exceeded you have exceeded your daily download allowance. Conventional direct field oriented control dfoc algorithms provide more precision for torque control than scalar schemes, but require sensors for the speed control of the rotor and the magnetic flux to provide the data for the foc algorithms. Pdf comparison of field oriented control and direct torque control.
This paper is aimed to give a contribution for a detailed comparison between the two control techniques, emphasizing advantages and disadvantages. Vector control method field oriented control is one of the vector control methods. Comparison of direct and indirect vector control of induction motor b. They also face challenges in the dynamic response and the.
When abb introduced its first direct torque control ac drive to the market in 1995, dtc was already a leading technology. Vector control, also called fieldoriented control foc, is a variablefrequency drive vfd control method in which the stator currents of a threephase ac electric motor are identified as two orthogonal components that can be visualized with a vector. Field oriented control foc and direct torque control dtc were chosen for simulation as they are standard induction motor control techniques. Direct torque control can be considered a simplified version of the foc oriented to the stator field and without any current control loops. This paper presents a comparison between sensor or indirect field oriented control ifoc and sensorless field oriented control sfoc in low frequency region for induction motor im. Pulse width modulated pwm drives rockwell automation. The comparison is based on various criteria including basic control characteristics, dynamic performance, and implementation complexity. The main characteristics of field oriented control and direct torque control schemes are studied by simulation, emphasizing their advantages and disadvantages. In this type of motor, the excitation for the stator and rotor is independently controlled.
The performances of the two control schemes are evaluated in terms of torque, current ripples and transient responses to load toque variations. A comparative study between field oriented control and. This involves calculating an estimate of the motors magnetic flux and torque based on the measured voltage and current of the motor. Sep 19, 2016 dtc is direct torque control, a method used by abb in their highperformance drives. The main feature of dtc is the high performance achieved with a simpler. Field oriented control field oriented control or offers more precise control of ac motors compared to scalar control.
303 1425 360 551 419 405 265 1422 1059 562 814 366 460 282 788 1043 699 850 1465 158 498 718 1118 265 134 914 105 333 1464 1178 686