An Advanced Power Electronics Interface for Electric Vehicles Applications

Abstract

Power electronics interfaces play an increasingly important role in the future clean vehicle technologies. This paper proposes a novel integrated power electronics interface (IPEI) for battery electric vehicles (BEVs) in order to optimize the performance of the power train. The proposed IPEI is responsible for the power-flow management for each operating mode. In this paper, an IPEI is proposed and designed to realize the integration of the dc/dc converter, on-board battery charger, and dc/ac inverter together in the BEV power train with high performance. The proposed concept can improve the system efficiency and reliability, can reduce the current and voltage ripples, and can reduce the size of the passive and active components in the BEV drive trains compared to other topologies. In addition, low electromagnetic interference and low stress in the power switching devices are expected. The proposed topology and its control strategy are designed and analyzed by using MATLAB/Simulink. The simulation results related to this research are presented and discussed. Finally, the proposed topology is experimentally validated with results obtained from the prototypes that have been built and integrated in our laboratory based on TMS320F2808 DSP.

Keywords

1.      Battery electric vehicles (BEVs)

2.      interleaved dc/dc converter

3.       on-board battery charger

4.      Power train control strategies

5.       Power train modeling

6.       small-signal model

Software: MATLAB/SIMULINK

Block Diagram:

Fig. 1. Schematic diagram of the battery electric vehicles.

Expected Simulation Results:

Fig2. Dynamic performance of the battery pack and the proposed IPEI (simulation result).

Fig3. Comparative efficiency of the ac drive system (Motor & ESI) in the

proposed powertrain (simulation result).

Fig4. Efficiencies of the power electronics interfaces in the proposed power train

(simulation result).

Fig5. Power train efficiency without including the battery efficiency (simulation

result).

Conclusion

In this paper, a novel integrated power electronic interface has been proposed for BEVs to optimize the performance of the powertrain. The proposed IPEI combines the features of the BMDIC and the ESI. The proposed IPEI and its performance characteristics have been analyzed and presented. Different control strategies are designed to verify the performance of the proposed IPEI during different operating modes. It should be pointed out that the IFOC based on PWM voltage and PSO is more efficient than IFOC based on PWM voltage which is used to drive the EM during traction and braking modes. Moreover, the proposed IPEI can achieve a high power factor correction, and can achieve a low THD for the input current during charging mode from the ac grid. As is clear from the simulation results, the proposed IPEI can reduce the current and voltage ripples, can improve the efficiency and reliability, and can provide a compact size for the BEV power train. Furthermore, the battery lifespan can be increased due to the ripple reduction. Finally, the simulation and experimental results have demonstrated that the proposed IPEI has been successfully realized and it promises significant savings in component count with high performance for BEVs compared to other topologies. Therefore, it can be expected that these topologies can be utilized for development of high efficiency BEV power trains.      

References:

[1] C. C. Chan, A. Bouscayrol, and K. Chen, “Electric, hybrid, and fuel-cell vehicles: Architectures and modeling,” IEEE Trans. Veh. Technol., vol. 59, no. 2, pp. 589–598, Feb. 2010.

[2] C. C. Chan, “The state of the art of electric and hybrid, and fuel cell vehicles,” Proc. IEEE, vol. 95, no. 4, pp. 704–718, Apr. 2007.

[3] A. Emadi, S. S.Williamson, and A. Khaligh, “Power electronics intensive solutions for advanced electric, hybrid electric, and fuel cell vehicular power systems,” IEEE Trans. Power Electron., vol. 21, no. 3, pp. 567– 577, May 2006. electronics and motor drives in electric, hybrid electric, and plug-in hybrid electric vehicles,” IEEE Trans. Ind. Electron, vol. 55, no. 6, pp. 2237–2245, Jun. 2008.

[4] A. Emadi, Y. J. Lee, and K. Rajashekara, “Power

[5] S. S. Raghavan, O. C. Onar, and A. Khaligh, “Power electronic interfaces for future plug-in transportation systems,” IEEE Power Electron. Soc. Newsletter, vol. 23, Third Quarter 2010.

Comparative Analysis of LCL Filter with Active and Passive Damping Methods for Grid-interactive Inverter System

ABSTRACT:

This paper presents the control strategy for a three phase LCL-filter type based grid connected inverter system for photovoltaic (PV) applications. The control strategy proposed in the paper involves the independent control of active and reactive power injected into the grid during steady state and transient conditions. In addition to that, a comparative study between active and passive damping configurations for LCL type filter resonance damping is also analyzed. The control strategy implemented on a three-phase grid connected PV inverter is studied and verified by computer simulation based on MATLAB Simulink and the results are analyzed for effectiveness of the study.

KEYWORDS:

1.      Renewable Energy Source (RES)

2.       LCL-Filter

3.      Proportional-Resonant (PR) Controller

4.      Active damping

5.      Passive damping

SOFTWARE: MATLAB/SIMULINK

SCHEMATIC DIAGRAM:

Fig.1. Schematic diagram of grid-connected inverter system with LCL filter

CONTROL DIAGRAM:

Fig.2. Over all control strategy of Grid-connected PWM VSI

EXPECTED SIMULATION RESULTS:

Fig.3. Simulation results for active damping method under steady state condition (a) grid voltage and grid Current waveforms (b) d and q-axis grid currents (c) response of active and reactive Power (d) response of dc-link voltage (e) THD of grid current.

Fig.4. Simulation results for passive damping method under steady state condition (a) grid voltage and grid Current waveforms (b) d and q-axis grid currents (c) response of active and reactive Power (d) response of dc-link voltage (e) THD of grid current.

Fig.5. Simulation results for active damping method during step change in the input PV power (a) step change in the input PV power (b) d and q-axis grid currents (c) response of dc-link voltage (d) THD of grid current

Fig.6. Simulation results for passive damping method during step change in the input PV power (a) d and q-axis grid currents (b) response of dc-link voltage (c) THD of grid current.

             

CONCLUSION:

The paper discusses the control strategy for gridconnected PWM VSI with LCL-type filter. The advantage feature of PR controller is the possibility of implementing harmonic compensator without interfering with control dynamics, achieving a high quality delivered current are explored. In addition, a comparative study has been made between active and passive damping methods to damp-out the LCL-filter resonance. From the above said discussions, it is found that active damping method is better than passive damping method to inject sinusoidal current into the grid with less THD. Also it ensures zero steady state error with stable response. In addition to that, passive damping method involves extra cost and losses due to additional circuit components. Nevertheless, active damping method difficult to implement, but overall performance of grid-connected PWM VSI is improved with higher efficiency

REFERENCES:

[1] O.Siddique, “The Green Grid: Energy Savings and Carbon Emission Reductions Enabled by a Smart Grid,” EPRI Palo Alto, CA: 2008

[2] F. Blaabjerg, Z. Chen, and S. Kjaer, “Power electronics as efficient interface in dispersed power generation systems,” IEEE Trans. Power Electron vol. 19, no. 5, pp. 1184–1194, Sep. 2004

[3] Bochuan Liu; Byeong-Mun Song, "Modeling and analysis of an LCL filter for grid-connected inverters in wind power generation systems," In Proc. 2011 IEEE Power and Energy Society General Meeting, , pp.1-6, July 2011.

[4] Wenqiang Zhao; Guozhu Chen, "Comparison of active and passive damping methods for application in high power active power filter with LCL-filter," In Proc. International Conference on Sustainable Power Generation and Supply, 2009. SUPERGEN '09. pp.1-6, April 2009.

[5] Hoff, B.; Sulkowski, W., "Grid connected VSI with LCL filter — Models and comparison," In. Proc. 2012 IEEE Energy Conversion Congress and Exposition (ECCE), pp.4635,4642, Sept. 2012.

Sensor Less Speed Control of PMSM using SVPWM Technique Based on MRAS Method for Various Speed and Load Variations

ABSTRACT:

The permanent magnet synchronous motor (PMSM) has emerged as an alternative to the induction motor because of the reduced size, high torque to current ratio, higher efficiency and power factor in many applications. Space Vector Pulse Width Modulation (SVPWM) technique is applied to the PMSM to obtain speed and current responses with the variation in load. This paper analysis the structure and equations of PMSM, SVPWM and voltage space vector process. The Model Reference Adaptive System (MRAS) is also studied. The PI controller uses from estimated speed feedback for the speed senseless control of PMSM based on SVPWM with MRAS. The control scheme is simulated in the MATLAB/Simulink software environment. The simulation result shows that the speed of rotor is estimated with high precision and response is considerable fast. The whole control system is effective, feasible and simple.

KEYWORDS:

1.      PMSM

2.      Space vector pulse width modulation

3.      Model reference adaptive system

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

                      

Fig. 1. Schematic Block of MRAS scheme

Fig. 2. Sensor less control block diagram with MRAS system

EXPECTED SIMULATION RESULTS:

Fig. 3. Reference and real speed of PMSM

Fig. 4. Electromagnetic torque of PMSM

Fig. 5. Reference and real speed of PMS

Fig. 6. Electromagnetic torque of PMSM

Fig. 7. Reference and real speed of PMSM

Fig. 8. Electromagnetic torque of PMSM

Fig. 9. Reference and real speed of PMSM

Fig. 10. Electromagnetic torque of PMSM

CONCLUSION:

A detailed Simulink model for a PMSM drive system with SVPWM based on model reference adaptive system has being developed. Mathematical model can be easily incorporated in the simulation and the presence of numerous toll boxes and support guides simplifies the simulation. The space vector pulse width modulation technique (SVPWM) control technique is used in PMSM drive which has its potential advantages, such as lower current waveform distortion, high utilization of DC voltage, low switching and noise losses, constant switching frequency and reduced torque pulsations provides a fast response and superior dynamic performance. Matlab/Simulink based computer simulation results shows that the adaptive algorithm improve dynamic response, reduces torque ripple, and extended speed range. Although this control algorithm does not require any integration of sensed variables.

REFERENCES:

 [1] Young Sam Kim, Sang Kyoon Kim, Young Ahn Kwon, “MRAS Based Sensorless vontrol of permanent magnet synchronous motor”, SICE Annual conference in Fukui, August 4-6,2003.

[2] Xiao Xi, LI Yongdong, Zhang Meng, Liang Yan, “A Sensorless Control Based on MRAS Method in Interior Pernanent-Magnet Machine Drive”, pp734-738, PEDS 2005.

[3] Zhang Bingy, Cen Xiangjun et al. “A pposition sensor less vector control system based on MRAS for low speeds and high torque PMSM drive”, Railway technology avalanche, vol.1, no.1, pp.6, 2003.

[4] P. Vas, “Sensorless Vector and Direct Torque Control”, Oxford University Press, 1988.

[5] A. K. Gupta and A. M. Khambadkone, “A Space Vector PWM Scheme for Multilevel Inverters Based on Two-Level Space Vector PWM,” IEEE Transactions on Industrial Electronics, vol. 53, no 5, pp. 1631-1639, Oct. 2006.

Sensorless Direct Torque and Indirect Flux Control of Brushless DC Motor with Non-Sinusoidal Back-EMF

 ABSTRACT:

In this paper, the position sensorless direct torque and indirect flux control (DTIFC) of BLDC motor with nonsinusoidal (non-ideal trapezoidal) back-EMF has been extensively investigated using three-phase conduction scheme with six-switch inverter. In the literature, several methods have been proposed to eliminate the low-frequency torque pulsations for BLDC motor drives such as Fourier series analysis of current waveforms and either iterative or least-mean-square minimization techniques. Most methods do not consider the stator flux linkage control, therefore possible high-speed operations are not feasible. In this work, a novel and simple approach to achieve a low-frequency torque ripple-free direct torque control with maximum efficiency based on dq reference frame similar to permanent magnet synchronous motor (PMSM) drives is presented. The electrical rotor position is estimated using winding inductance, and the stationary reference frame stator flux linkages and currents. The proposed sensorless DTC method controls the torque directly and stator flux amplitude indirectly using d–axis current. Since stator flux is controllable, flux-weakening operation is possible. Moreover, this method also permits to regulate the varying signals. Simple voltage vector selection look-up table is designed to obtain fast torque and flux control. Furthermore, to eliminate the low-frequency torque oscillations, two actual and easily available line-to-line back- EMF constants (kba and kca) according to electrical rotor position are obtained offline and converted to the dq frame equivalents using the new Line-to-Line Park Transformation. Then, they are set up in the look-up table for torque estimation. The validity and practical applications of the proposed three-phase conduction DTC of BLDC motor drive scheme are verified through simulations and experimental results.

KEYWORDS:

1.      Brushless dc (BLDC) motor

2.       Position sensorless control

3.      Direct torque control (DTC)

4.       Stator flux control

5.       Fast torque response

6.       Non-sinusoidal back-EMF

7.       Low frequency torque ripples

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

 Fig. 1. Overall block diagram of the position sensorless direct torque and indirect flux control (DTIFC) of BLDC motor drive using three-phase conduction mode.

EXPECTED SIMULATION RESULTS:

                                            

Fig. 2. Simulated indirectly controlled stator flux linkage trajectory under the sensorless three-phase conduction DTC of a BLDC motor drive when  is changed from 0 A to -5 A under 0.5 N·m load torque.

                                                    

Fig. 3. Actual q– and d–axis rotor reference frame back-EMF constants versus electrical rotor position  and 

                                    

Fig.4. Steady-state and transient behavior of the experimental (a) q–axis stator current, (b) d–axis stator current, (c) estimated electromagnetic torque and (d) ba–ca frame currents when  under 0.5 N·m load torque.

                                                 

Fig. 5. Experimental indirectly controlled stator flux linkage trajectory under the sensorless three-phase conduction DTC of a BLDC motor drive when  at 0.5 N·m load torque.

                                            

Fig. 6. Steady-state and transient behavior of the actual and estimated electrical rotor positions from top to bottom, respectively under 0.5 N·m load torque.

CONCLUSION:

This study has successfully demonstrated application of the proposed position sensorless three-phase conduction direct torque control (DTC) scheme for BLDC motor drives. It is shown that the BLDC motor could also operate in the field weakening field weakening region by properly selecting the d–axis current reference in the proposed DTC scheme. First, practically available actual two line-to-line back-EMF constants (%"# and %$#) versus electrical rotor position are obtained using generator test and converted to the dq frame equivalents usingthe new Line-to-Line Park Transformation in which only two input variables are required. Then, they are used in the torque estimation algorithm. Electrical rotor position required in the torque estimation is obtained using winding inductance, stationary reference frame currents and stator flux linkages. Since the actual back-EMF waveforms are used in the torque estimation, low-frequency torque oscillations can be reduced convincingly compared to the one with the ideal trapezoidal waveforms having 120 electrical degree flat top. A look-up table for the three-phase voltage vector selection is designed similar to a DTC of PMSM drive to provide fast torque and flux control. Because the actual rotor flux linkage is not sinusoidal, stator flux control with constant reference is not viable anymore. Therefore, indirect stator flux control is performed by controlling the flux related d–axis current using bang-bang (hysteresis) control which provides acceptable control of time-varying signals (reference and/or feedback) quite well. Since the proposed DTC scheme does not involve any PWM strategies, PI controllers as well as inverse Park and Clarke Transformations to drive the motor, much simpler overall control is achieved.

REFERENCES:

[1] I. Takahashi and T. Noguchi, “A new quick-response and high efficiency control strategies of an induction motor,” IEEE Trans. Ind. Appl., vol. 22, no. 5, pp. 820–827, Sep./Oct. 1986.

[2] M. Depenbrock, “Direct self-control of inverter-fed induction machine,” IEEE Trans. Power Electron., vol. 3, no. 4, pp. 420–429, Oct. 1988.

[3] L. Zhong, M. F. Rahman, W. Y. Hu, and K. W. Lim, “Analysis of direct torque control in permanent magnet synchronous motor drives,” IEEE Trans. Power Electron., vol. 12, no. 3, pp. 528–536, May 1997.

[4] Y. Liu, Z. Q. Zhu, and D. Howe, “Direct torque control of brushless dc drives with reduced torque ripple,” IEEE Trans. Ind. Appl., vol. 41, no. 2, pp. 599–608, Mar./Apr. 2005.

[5] S. B. Ozturk and H. A. Toliyat, “Direct torque control of brushless dc motor with non-sinusoidal back-EMF,” in Proc. IEEE-IEMDC Biennial Meeting, Antalya, Turkey, May 3-5, 2007.

High-Performance Multilevel Inverter Drive of Brushless DC Motor

ABSTRACT:

The brushless DC (BLDC) motor has numerous applications in high-power systems; it is simple in construction, is cheap, requires less maintenance, has higher efficiency, and has high power in the output unit. The BLDC motor is driven by an inverter. This paper presents design and simulation for a three-phase three-level inverter to drive the BLDC motor. The multilevel inverter is driven by discrete three-phase pulse width modulation (DPWM) generator that forced-commuted the IGBT’s three-level converters using three bridges to vectored outputs 12- pulses with three levels. Using DPWM with a three-level inverter solves the problem of harmonic distortions and low electromagnetic interference. This topology can attract attention in high-power and high-performance voltage applications. It provides a three-phase voltage source with amplitude, phase, and frequency that are controllable. The proposed model is used with the PID controller to follow the reference speed signal designed by variable steps. The system design is simulated by using Matlab/Simulink. Satisfactory results and high performance of the control with steady state and transient response are obtained. The results of the proposed model are compared with the variable DC-link control. The results of the proposed model are more stable and reliable.

KEYWORDS:

1.      Brushless DC Motor

2.       Multilevel Inverter

3.       High-Performance Drive

4.       Pulse Width Modulation (PWM)

5.      Maltlab

6.      Simulink

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

             

                                                    Figure 1. Block diagram of a BLDC motor drive [18].

EXPECTED SIMULATION RESULTS:

                                       

Figure. 2. Output of three-phase three-level inverter with DPWM.

                                      

Figure 3. The sample from output of the DPWM

                                          

Figure 4. Analysis of response for the proposed MLI with PID controller of BLDC motor.

                                             

Figure 5. Two outputs of controllers with proposed MLI and variable DC-link

CONCLUSION:

The proposed MLI performance analysis was successfully presented by using Matlab/Simulink software. The proposed topology can be easily extended to a higher-level inverter. The simulation results were sine waves and exhibited fewer ripples and low losses. This system would show its feasibility in practice. The vector control was described in adequate detail and was implemented with a three-level MLI. This method enabled the operation of the drive at zero direct axis stator current. Transient results were obtained when a DPWM was started from a standstill to a required speed. The performance of the vector control in achieving a fast reversal of PDPWM even at very high speed ranges is quite satisfactory. The performance of the proposed three-phase MLI was investigated and was found to be quite satisfactory. A comparison was made between the PID controller–based proposed model MLI and the controller with variable DC-link voltage. The results showed that the proposed model responded better in transient and steady states and was more reliability with high performance.

REFERENCES:

[1] P. D. Kiran, M. Ramachandra, “Two-Level and Five-Level Inverter Fed BLDC Motor Drives”, International Journal of Electrical and Electronics Engineering Research, Vol. 3, Issue 3, pp 71-82, Aug 2013

[2] N. Karthika, A. Sangari, R. Umamaheswari , “Performance Analysis of Multi Level Inverter with DC Link Switches for Renewable Energy Resources”, International Journal of Innovative Technology and Exploring Engineering, Volume-2, Issue-6, pp 171-176, May 2013

[3] A. Jalilvand R. Noroozian M. Darabian, “Modeling and Control Of Multi-Level Inverter for Three-Phase Grid-Connected Photovoltaic Sources”, International Journal on Technical and Physical Problems of Engineering, Iss. 15, Vol. 5, No.2, pp 35-43, June 2013

[4] P. Karuppanan, K. Mahapatra, “PI, PID and Fuzzy Logic Controlled Cascaded Voltage Source Inverter Based Active Filter For Power Line Conditioners”, Wseas Transactions On Power Systems, Issue 4, Volume 6, pp 100-109, October 2011

[5] D. Balakrishnan, D. Shanmugam, K.Indiradevi, “Modified Multilevel Inverter Topology for Grid Connected PV Systems”, American Journal of Engineering Research, Vol. 02, Iss.10, pp-378-384, 2013