Current Control of BLDC Drives for EV Application

ABSTRACT:

This paper presents a current blocking strategy of brushless DC (BLDC) motor drive to prolong the capacity voltage of batteries per charge in electric vehicle applications. The BLDC motor employs a simple torque hysteresis control (THC) that can offer a robust control and quick torque dynamic performance. At first, a mathematical modeling of BLDC motor and principle of torque hysteresis control will be described, so that the benefit offered by the proposed current blocking strategy can be highlighted. It can be shown that the current control method naturally provides current limitation, in which the current error (or ripple) is restricted within the pre-defined band-gap furthermore provide current protection. The benefit of proposed current blocking strategy will be highlighted such that it can prevent the current drained from the batteries when the torque demand is released to set to 0 Nm. The control scheme is validated and verified by the simulation and experimental results.

KEYWORDS:

1.      Components

2.      Brushless DC motor

3.      Hall effect

4.      Current controller

5.      Electric vehicle (EV)

6.      Hybrid electric vehicle (HEV)

7.      Torque hysteresis controller (THC)

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

 

Fig 1. Structure of Optimal Current Control drive for BLDC motor.

 CONTROL BLOCK DIAGRAM:

               

Fig 2. Proposed current blocking strategy based on hysteresis comparator

 EXPECTED SIMULATION RESULTS:

         

                   

Fig 3. Motor currents are controlled such that follow their references which are generated according to the hall effect signals (Time/div=0.5s/div).

                

                        

Fig 4. Waveforms of output torque, speed and currents (a) THC without current blocking strategy (b) THC with current blocking strategy.

CONCLUSION:

This paper presented the modelling and experimental result of THC for BLDC motor. The current controller has been applied to a BLDC drive and the results shows that the current ripple stays within the hysteresis band as defined by the controller. The proposed current blocking strategy shows that the energy wastage from the batteries is prevented such that it can prolong the capacity of voltage battery and it also showed that the hysteresis controller can offer inherent current protection/limitation and robustness in controlling the motor torque.

REFERENCES:

[1] Lefley, P., L. Petkovska, and G. Cvetkovski. Optimization of the design parameters of an asymmetric brushless DC motor for cogging torque minimization in Power Electronics and Applications (EPE 2011), Proceeding of the 2011-14th European Conference on 2011.

[2] Bahari N., Jidin A., Abdullah A. R. and Othman M. N., “Modeling and Simulation of Torque Hysteresis Controller for Brushless DC Motor Drives”, IEEE Symposium on Industrial Electronics and Applications ISIEA, 2012.

[3] Mayer, J.S. and O. Wasynczuk, “Analysis and modelling of a single-phase brushless DC motor drive system”, Energy Conversion, IEEE Transactions on, 1989. 4(3): p. 473-479.

[4] Jidin, A., Idris, N. R. N., Yatim, A. H. M., Sutikno, T. and Elbuluk, M. E. ‘An Optimized Switching Strategy for Quick Dynamic Torque Control in DTC-Hysteresis-Based Induction Machines’, IEEE Transactions on Industrial Electronics,2011, Vol. 58, pp. 3391-3400.

[5] Norhazilina Binti Bahari; Jidin, Auzani bin; Abdullah, Abdul Rahim bin; Md Nazri bin Othman; Manap, Mustafa bin, "Modeling and simulation of torque hysteresis controller for brushless DC motor drives," Industrial Electronics and Applications (ISIEA), 2012 IEEE Symposium on , vol., no., pp.152,155, 23-26 Sept. 2012

Transient and Steady States Analysis of Traction Motor Drive with Regenerative Braking and Using Modified Direct Torque Control (SVM-DTC)

ABSTRACT:

Direct torque control (DTC) is a suitable control method for electric drives which are supplied by inverters, specially voltage source inverters (VSI). This method has some advantages compared with other methods such as field oriented control (FOC) with some drawbacks like switching frequency variation, that leads to introduce DTC improvement methods. Using space vector modulator (SVM) in DTC structure is the most important method that is referred to as space vector modulator for direct torque control (SVM-DTC). Utilizing regenerative braking method in electrical transportation makes it necessary to analyze the traction motor behavior in regenerative braking mode. In this paper three major types of SVM-DTC are mentioned and SVM-DTC method with Closed Loop Torque and Flux Control in the Stator flux coordinates is used for simulation of traction motor driver of Ghatar Shahri Esfahan Organization. Moreover, traction motor behavior in regenerative braking mode using SVM-DTC driver is simulated.The simulation results are analyzed in the paper

KEYWORDS:

                                 1.Direct Torque Control (DTC)

                                 2. Space Vector Modulation (SVM)

                                 3. Traction Motor Drive

                                 4. Speed Control of Induction Motors

                                 5. Regenerative Braking.

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Block diagram of DTC

Fig. 2. Block diagram of SVM-DTC based on closed loop flux and torque control in stator flux coordinates

SIMULATION RESULTS:

                             

Fig. 3. Applied load torque at speed 0[201.4 rad/s.

                              

Fig. 4. Simulation results of SVM-DTC with reference speed of 201.4 rad/

Fig. 5. Applied load torque at speed of 170 rad/s

Fig. 6.simulation results of SVM-DTC with reference speed of 170 rad/s.

                        

Fig. 7 DC-link behavior during regenerative braking with and without regenerated energy absorption.

                              

Fig. 8. Traction motor and DC-link behavior during regenerative braking with regenerated energy absorption.

CONCLUSION:

In the case of induction traction motor control methods ,DTC has better performance. DTC has some shortcoming such as varying switching frequency proportional to motor speed variation. Therefore, it is necessary to use maximum sampling frequency in DTC. These issues result in increasing flux ripple in lower speed and increasing torque ripple in higher speed in addition to increasing switching loss. SVM-DTC with fixed switching frequency solves these problems significantly. Among different methods of electrical braking, regenerative braking has special advantages such as reduction in energy consumption and improvement in power quality of DC link. SVM-DTC operation is also appropriate and acceptable in regenerative braking. Therefore, it is suggested to utilize SVM-DTC in electric rail transportation applications

REFERENCES:

[1] Sergaki, E.S.; Moustaizis, S.D., "Efficiency optimization of a direct torque controlled induction motor used in hybrid electric vehicles," Electrical Machines and Power Electronics and 2011 Electro motion Joint Conference (ACEMP), 20111nternational Aegean Conference on , vol., no., pp.398,403, 8-10 Sept. 2011

[2] Zhongbo Peng; XueFeng Han; Zixue Du, "Direct Torque Control for Electric Vehicle Driver Motor Based on Extended Kalman Filter," Vehicular Technology Conference Fall (VTC 201 a-Fall), 2010 IEEE 72nd , vol., no., pp.I,4, 6-9 Sept. 2010

[3] Rehman H, Longya X. Alternative energy vehicles drive system: control, flux and torque estimation, and efficiency optimization. IEEE Trans Veh Technol 2011; 60:3625-34.

[4] Rongmei, P. L., et al. "A Novel Fast Braking System for Induction Motor. " international Journal of Engineering and innovative Technology (IJEIT), vol. 1,2012.

[5] H. Abu-Rub, A. Iqbal, and 1. Guzinski, "Direct Torque Control of AC Machines," in High Performance Control of AC Drives with MATLABISimulink Models, John Wiley & Sons, Ltd, 2012, pp. 171-254.

Space-Vector PWM Inverter Feeding a Permanent-Magnet Synchronous Motor

ABSTRACT:

The paper presents a space-vector pulse width modulation (SVPWM) inverter feeding a permanent-magnet synchronous motor (PMSM). The SVPWM inverter enables to feedthe motor with a higher voltage with low harmonic distortions than the conventional sinusoidal PWM inverter. The control strategy of the inverter is the voltage / frequency control method, which is based on the space-vector modulation technique. The proposed PMSM drive system involving the field-oriented control scheme not only decouples the torque and flux which provides faster response but also makes the control task easy. The performance of the proposed drive is simulated. The advantages of the proposed drive are confirmed by

the simulation results

KEYWORDS:

1.      Permanent-magnet synchronous motor

2.      Space-vector PWM inverter

3.      Voltage/frequency control

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

Fig. 1 Three-phase VSI bridge circuit

EXPECTED SIMULATION RESULTS:

     (a) voltage waveform                              

(b) voltage spectrum (peak value) and THD

Fig. 2 Phase voltage of the motor at fo=50 Hz and M= 0.38

(a) voltage waveform

                                                                                 

(b) voltage spectrum (peak value) and THD

Fig.3 Line voltage of the motor at fo=50 Hz and M=0.38

        

Fig. 4 Locus of reference input voltage vector in the (α − β ) plane     

                                                                 

Fig. 5 Locus of actual output voltage vector  in the (α − β ) plane

   

(a)      current waveform            

                             

                     

(b) current spectrum (peak value) and THD

  Fig. 6 Current of the motor at fo=50 Hz,M=0.38, and T=1.5 N.m

           (a) current waveform                                                       

(b)current spectrum (peak value) and THD

Fig. 7 Current of the motor at fo=50 Hz, M=0.38, and T=3 N.m

 Fig. 8 Speed response of the motor drive system at load T=3 N.m

CONCLUSION:

In this paper, a SVPWM-PMSM drive has been introduced. The SVPWM inverter is used to offer 15%increase in the output voltage and low output harmonic distortions compared with the conventional sinusoidal PWM inverter. The control strategy of the SVPWM inverter is the voltage/frequency control method which is based on the space-vector modulation technique for constant torque operation. The advantages of the proposed drive are confirmed by the simulation results.

REFERENCES:

[1] R. Arulmozhiyal, and K. Baskaran, "Space vector pulse width modulation based speed control of induction motor using fuzzy PI controller, " International Journal of Computer and Electrical Engineering, vol. 1, no. 1, April 2009, pp. 98-103

 [2] Z. Wang, J. Jin, Y. Guo, and J. Zhu, "SVPWM techniques and applications in HTS PMSM machines control," Journal of Electronic Science and Technology of China, vol. 6, no. 2, June 2008, pp. 191-197.

[3] A. Maamoun, A. Soliman, and A. M. Kheirelden, "Space-vector PWM inverter feeding a small induction motor," in Proc. IEEE Int. Conf. onMechatronics, Komamoto, Japan, May 2007, pp. 1-4.

[4] W. Kaewjinda, and M. Konghirun, "Vector control drive of permanentmagnet synchronous motor using resolver sensor," ECTI Trans. Electrical Eng., Electronics, and Communications, Thailand, vol. 5, no. 1, Feb. 2007, pp. 134-138.

[5] M. Štulrajter, V. Hrabovcová, and M. Franko, "Permanent magnets synchronous motor control theory,"Journal of Electrical Engineering,Slovak Republic, vol. 58, no. 2, 2007, pp. 79-84

Sliding Mode MRAS Speed Sensor less Vector Control for Submersible Motor

 ABSTRACT:

In consideration of the difficulty to install speed sensor result from special high temperature working environment of submersible motor, in this paper, a method of sliding mode model reference adaptive observer(SMMRAS) is used to estimate the speed of sensor less vector controlled submersible motor. This method combines variable structure control with model reference adaptive system (MRAS) to improve the accuracy of speed identification, and the stability and speediness capability of the system are proved by Lyapunov theory. The model of the speed-sensor less vector control system of induction motor is built by MatLab/Simulink. Theoretical analysis and the MATLAB simulation results show that the proposed method used in the system for speed identification has rapid response, and the static and dynamic performance is also perfect

.

KEYWORDS:

1.      Submersible motor

2.      Speed sensor less

3.       Model reference adaptive system

4.      MRAS

5.      Speed estimation

SOFTWARE: MATLAB/SIMULINK

CONTROL SYSTEM:

Fig. 1. Speed identification scheme based upon MRAS

Fig. 2. Speed identification scheme based upon SM MRAS

EXPECTED SIMULATION RESULTS:

a)       Actual speed and estimated speed    

                 

                         

                                                          b) Torque response

Fig. 3Speed and torque curve when load increasing

                                                                        

                                       

                                  (a)    Actual speed and estimated speed  

                       

                              

                                                      (b) Torque response                                                                                                             

Fig4. Speed and torque curve of starting and braking

CONCLUSION:

In this paper the sliding mode speed observer is established. Stability  conditions of a model convergence is introduced by the Lyapunov stability theory. Use the space vector pulse width modulation (SVPWM) technology make the voltage control signal of motor is better optimization. Siding mode speed observer is to reduce the influence of parameters on the system, and to improve the accuracy of the speed identification. In this paper the method can better to achieve the speed identification of motor, has robustness to the parameter changes, can quickly follow the actual rational speed changes. Simulation results were given in the transient and steady states for various operating condition. The simulation results verify that the proposed control schemes provide good dynamics performance in tracking accuracy and disturbance rejection

REFERENCES:

 [1] Wang Y N, Wang H, Qiu S H, et al. The field-oriented control for speed-sensor less induction motor drive based on recurrent fuzzy neural network[J]. Proceedings of the CSEE,2004,24(5):84- 89(in Chinese).

[2] Su W F,Liu C W,Sun X D,et al.Speed controller for induction motors based on kalman filtering[J].Journal of Tsinghua University(Science and Technology),2003,43(9): 1202-1205(in Chinese)

.[3] Zhang P F, Peng W D, Liu X G. Control of Induction Motor Based on

Model Reference Adaptive System[J].2011,34(1):197-199.

[4] Deng H, Xue B, Xu D G, Yang Jing. Speed Estimation for Submersible Motor Based on Elman Neural Network[J]. Proceedings of the CSEE,2007,27(24):102-106(in Chinese).

[5] Schauder C. Adaptive speed identification for vector control of induction motors without rotational transducers[J].IEEE Transactions on Industry Applications,1992,28(5):1054-1061.