Please use this identifier to cite or link to this item:
|Direct Torque Control of Permanent Magnet Synchronous Motor Using Three Level Inverter
Duvvuri, SSSR Sarathbabu
|PMSM,SVPWM, DTC, Three Level Inverter
|Permanent Magnet synchronous motors (PMSMs) are used in many applications that require rapid torque response and high-performance operation. The PMSM is very similar to the standard wound rotor synchronous machine except that the PMSM has no damper windings and excitation is provided by a permanent magnet instead of a field winding. The elimination of field coil, dc supply and slip rings reduce the motor loss and complexity. For the same frame size, permanent magnet motors have higher pull out torque. It is mathematically proven that the increase of electromagnetic torque in a permanent magnet motor is proportional to the increase of the angle between the stator and rotor flux linkages, and, therefore, the fast torque response can be obtained by adjusting the rotating speed of the stator flux linkage as fast as possible. This is achieved by using direct torque control (DTC) technique. The Direct Torque Control (DTC) has been more and more used in industrial applications with permanent magnet synchronous motor (PMSM) using two level voltage source three-phase inverter with hysteresis controller due to some advantages like: more simplicity, low dependency on the motor parameters, good dynamic torque response. This type of drive system is named as classic PMSM DTC. However, the classic PMSM DTC has some problems like more torque and flux ripples as well as more harmonic contents in the stator current. Hence, to overcome these problems a novel DTC algorithm is proposed for three-phase induction motor which employs a three-level inverter. It is an extension of the classic DTC for two-level inverters. The basic principle of DTC is to directly select stator voltage vectors according to the differences between the references of torque and stator flux linkage and their actual values. The basic theory of operation for the control technique is presented. A mathematical model for the proposed DTC of the PMSM topology is developed. A simulation model is developed in MATLAB/SIMULINK and is used to verify the basic operation (performance) of the DTC technique.
|M.E. (Power Systems and Electric Drives)
|Appears in Collections:
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.