International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 03 Issue: 12 | Dec -2016 www.irjet.net p-ISSN: 2395-0072 © 2016, IRJET | Impact Factor value: 4.45 | ISO 9001:2008 Certified Journal | Page 364 Scalar control of Permanent Magnet Synchronous motor Yashvi Parmar 1 , Priyanka Patel 2 , Nitiksha Pancholi 3 , Chand Thakor 4 , Unnati Mali 5 12345 Assistant Professor, Dept. of Electrical Engineering, C.G. Patel Institute of Technology, Gujarat, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract – Permanent Magnet Synchronous Motors (PMSM) are attractive growing for a wide range of industrial drives and servo applications. There are various control strategies of speed control of Permanent Magnet Synchronous Motor. This paper represents scalar control Strategy for speed control of PMSM motor drive. It includes Mathematical model of PMSM, Vabc to Vdq conversion and simulation of Scalar control strategy. Key Words: control strategies, speed control, PMSM, scalar control, simulation 1. INTRODUCTION Permanent Magnet Synchronous Motors (PMSM) are attractive growing for a wide range of industrial drives and servo applications. Synchronous Motors have to be driven by a Variable Frequency Drive (VFD) to be able to run at different speeds. Control methods for electric motors can be divided into two main categories depending of what quantities they control. 1.1 VARIOUS CONTOL STRATEGIES OF PMSM Fig -1: Some common control techniques used for PMSM 1.2 Scalar control Scalar Control controls only magnitudes. The simplest method to control a PMSM is scalar control, where the relationship between voltage or current and frequency are kept constant through the motors speed range. The frequency is set according to the wanted synchronous speed and the magnitude of the voltage/current is adjusted to keep the ratio between them constant. No control over angles is utilized, hence the name scalar control. The method uses an open-loop control approach without any feedback of motor parameters or its position. This makes the method easy to implement and with low demands on computation power of the control hardware, but its simplicity also comes with some disadvantages. One of them are instability of the drive system after exceeding a certain applied frequency, to overcome this the rotor has to be constructed with damper windings to assure synchronization of the rotor to the electrical frequency. This will limit the number of design choices for the rotor, e.g. the magnets has to be located on the inside of the damper bars. Most PMSM are therefore constructed without damper windings, and they are not suitable for traditional scalar control. Another drawback with the lack of feedback is the systems low dynamic performance, which limits the use of this control method to e.g. fan- and pump-drives. 1.2.1 volt/frequency control Fig -2: Block diagram of v/f control Variable Scalar control Vector control Volts/Hertz FOC DTC DSC DTC- SVM