Introduction

Permanent Magnet Synchronous Motors (PMSM) are widely used in industrial applications, such as robots, and hybrid vehicle. PMSM has a high performances, very good controllability in full speed operating range, high efficiency (Lyshevski, (2000)) and small size in comparing with other motor types. For these properties, PMSM has become the preferred choice for hybrid electrical vehicle in order to use power more efficiently, due to the increasing demand and price of fuel and environmental regulation.

Field Oriented control (FOC) or Vector Control is the most efficient method of control PMSM. To implement the control theory, PMSM must power by inverter, such as voltage source inverter,  in order  to control  the  magnitude, phase,  and  frequency  of the  stator current waveform.  Furthermore, the field oriented  control requires the PMSM model in rotating “dq0” coordinate frame for implementing  its theory.

 

Objectives

Objective of this research is to control the speed of PMSM using FOC theory. Consequently, FOC needs two PI controller to regulate and one to regulate the speed. Therefore, designing FOC in which designing the SPWM, Clark and Park transformation, Three Phase Inverter and tuning PI controllers are the major goal of this investigation for controlling the speed Of PMSM. Initially, PI controllers and system responses are computed by using MATLAB simulation. Using frequency response and symmetric optimum tuning methods, PI controllers are calculated from closed loop system. In conclusion, the Field Oriented Control is designed and the system response is obtained for the speed control of PMSM using FOC in MATLAB Simulink.

Group Members

  • Umair

    (CU-169-2016)         

  • Waseem Asad

    (CU-154-2016)

  • Tahir Afridi

    (CU-185-2016)

Supervisor

  • Supervisor  Engineer  Zaheer  Farooq

     

Introduction:

A velocity and current double closed-loop control strategy is employed in this system, considering the characteristics of strong coupling, time-varying and nonlinear, the SPWM algorithm is used in the inner loop; In order to enhance the robustness and anti-interference ability, PI speed controller is used in the outer loop. Schematic diagram of control system is shown in Fig. (1). The system consists of coordinate transformation, SPWM, three-phase Multi-inverter, speed and position signal modules and PI controller.

Simulation:

Simulation of FOC drive system of PMSM is based on the mathematical model and the motor equations. It is built on several blocks such as DQ model of PMSM, Park and Inverse Park  transformation  block, speed  block,  PI  control,  SPWM  generator and inverter.

Torque calculation and speed calculation block diagram.

Park and inverse park transformation blocks are used for conversion of parameters in different  phase  domains.  They  are  also  referred  as  abc-dq  and  dq-abc  transformation  as illustrated in Figure 3.

12-level SPWM generation block as shown in Figure 4, is used to compare calculated phase current Iabc (ref) with the current reading from motor Iabc and generate spwm signals, which is fed to the inverter. PWM  signals from  SPWM  generation block  controls  the inverter’s phase voltage.

Block Diagram of SPWM

Three-level Inverter model is shown in Figure 5. For each phase, four switches are used, two for positive half cycle of AC and two for negative half cycle of AC. These voltage are controlled by Mosfets used in inverter.

Conclusion:

The performance analysis of FOC, three level inverters fed to PMSM drive is analyzed for Electric Vehicle applications. The modulation techniques used are SPWM. It is observed that speed accuracy and response is so good and quick that at 0.03sec it has achieved the reference speed as shown in figure 8. In the future the modulation technique can get better also increase in the level of inverter(as it reduce the distortion)

 

Commercialization:

This project is completely designed for electric car industries.

Over 300 + Alumni Working in leading national & international firms

Including  TCON Constructions, UAE, GEM – UAE, Daud Sons, Bacha Khan International Airport