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Monday 2 March 2020

SVM–DTC Permanent Magnet Synchronous Motor Driven Electric Vehicle with Bidirectional Converter


ABSTRACT:
Electric Vehicle (EV) technology provides an effective solution for achieving better performance compared to conventional vehicles. This paper highlights the use of a bidirectional buck-boost converter for a Permanent Magnet Synchronous Motor (PMSM) driven EV. The bidirectional buck–boost converter interfaces the low-voltage battery with a high-voltage dc bus and maintains a bidirectional power flow. The batteries are at low voltage to obtain higher volumetric efficiencies, and the dc link is at higher voltage to have higher efficiency on the motor side. PMSMs are known as a good candidate for EV due to their superior properties such as high torque/volume ratio, power factor and high efficiency. This paper also includes Space Vector Modulation (SVM) based Direct Torque Control (DTC) which controls the PMSM to reduce the ripples in both torque and speed. A closed loop control system with a Proportional Integral (PI) controller in the speed loop has been designed to operate in constant torque and flux weakening regions. Extensive simulation work was carried out using Matlab/ Simulink, and the results established shows that the performance of the controller both in transient as well as in steady state is quite satisfactory.
KEYWORDS:
1.      Permanent Magnet Synchronous Motor (PMSM)
2.      Electric vehicle
3.      Simulation
4.       SVM
5.      DTC bidirectional converter
SOFTWARE: MATLAB/SIMULINK
BLOCK DIAGRAM:





Fig. 1: Schematic diagram of the proposed system

EXPERIMENTAL RESULTS:



Fig. 2: Response of reference torque and generated torque

Fig. 3: Response of reference Speed and generated Speed



Fig. 4: Stator Flux

Fig. 5: Stator Flux Trajectory

Fig. 6: Velocity of traction system



Fig. 7: Response of dc link voltage

Fig. 8: Transient state of dc link voltage




Fig. 9: Phase Current of PMSM

CONCLUSION:
The present paper has presented a bidirectional buck boost converter for a PMSM drive controlled by SVM based DTC. This controller determinates the desired amplitude of torque hysteresis band. It is shown that the proposed scheme results in improved stator flux and torque responses under steady state condition. The main advantage is the improvement of torque and flux ripple characteristics at any speed region; this provides an opportunity for motor operation under minimum switching loss and noise. So this produces the required torque with minimum torque ripples. A speed controller has been designed successfully for closed loop operation of the PMSM drive system so that the motor runs at the commanded or reference speed. The simulated system has a fast response with zero steady state error thus validating the design method of the speed controller.
REFERENCES:
[1] D. Sandalow, Ending Oil Dependence. Washington, D.C.: The Brookings Institution, Jan. 2007
[2] A. Emadi, Y. J. Lee, and K. Rajashekara, “Power 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.
[3] F. Caricchi, F. Crescimbini, G. Noia, and D. Pirolo, “Experimental study of a bidirectional DC–DC converter for the DC link voltage control and the regenerative braking in PM motor drives devoted to electrical vehicles,” in Proc. IEEE APEC, Orlando, FL, Feb. 1994, vol. 1, pp. 381–386
[4] Enrique L. Carrillo Arroyo, “Modeling and simulation of permanent magnet synchronous motor drive system,” M.S Thesis 2006.
[5] J. Rais, M. P. DonsiĆ³n, “Permanent Magnet Synchronous Motors (PMSM). Parameters influence on the synchronization process of a PMSM,” Articel

Thursday 27 February 2020

Implementation of Solar Photovoltaic System with Universal Active Filtering Capability



ABSTRACT:
In this work, a novel technique based on second order sequence filter and proportional resonant controller is proposed for control of universal active power filter integrated with PV array (UAPF-PV). Using a second order sequence filter and sampling it at zero crossing instant of the load voltage, the active component of distorted load current is estimated, which is used to generate reference signal for shunt active filter. The proposed method has good accuracy in extracting fundamental active component of distorted and unbalanced load currents with reduced mathematical computations. Along with power quality improvement, the system also generates clean energy through the PV array system integrated to its DC-link. The UAPF-PV  integrates benefits of power quality improvement and distributed generation. The system performance is experimentally evaluated on a prototype in the laboratory under a variety of disturbance conditions such as PCC voltage fall/rise, load unbalancing and variation in solar irradiation.
KEYWORDS:
1.      Power quality
2.      Universal active power filter
3.      Adaptive filtering
4.      Photovoltaic array
5.      Maximum power point tracking
6.      Sequence filter
SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:



Fig.1. System configuration of UAPF-PV System


EXPERIMENTAL RESULTS:


Fig. 2. Simulated Performance of UAPF-PV under Sags and Swells in
Voltages at the PCC


Fig. 3. Simulated Performance of UAPF-PV System under load unbalance
Condition






Fig. 4. Simulated Performance of UAPF-PV System under irradiation
Variation




      (a) Harmonic Spectra and THD of Grid Current                              (b) Harmonic Spectra and THD of
                                                                         Load Current
Fig. 5. Steady State Performance of UAPF-PV System


CONCLUSION:
The performance of a novel control technique for solar PV system with universal active filtering, has been evaluated. The fundamental positive sequence components of nonlinear load currents are extracted using a second order sequence filter along with a zero cross detection technique. The series active filter is controlled using a proportional resonant controller implemented in Ī± − Ī² domain along with feedforward component. The system performs satisfactorily under disturbances such as PCC voltage dip/rise, changes in solar radiation and load disturbances. Apart from improving power quality, the system also supplies power from a PV array into the grid. A comparison of the proposed control shows that the system has improved performance as compared to conventional control techniques with low computational burden. The system integrates distributed generation along with enhancing power quality of distribution system.
REFERENCES:
[1] S. J. Pinto, G. Panda, and R. Peesapati, “An implementation of hybrid control strategy for distributed generation system interface using Xilinx system generator,” IEEE Transactions on Industrial Informatics, vol. 13, no. 5, pp. 2735–2745, Oct 2017.           
[2] B. Singh, A. Chandra, K. A. Haddad, Power Quality: Problems and Mitigation Techniques. London: Wiley, 2015.
[3] S. Singh, B. Singh, G. Bhuvaneswari, and V. Bist, “A power quality improved bridgeless converter-based computer power supply,” IEEE Transactions on Industry Applications, vol. 52, no. 5, pp. 4385–4394, Sept 2016.
[4] M. Peterson and B. N. Singh, “Multipulse controlled ac-dc converters for harmonic mitigation and reactive power management,” IET Power Electronics, vol. 2, no. 4, pp. 443–455, July 2009.
[5] B. Singh, M. Kandpal, and I. Hussain, “Control of grid tied smart pv dstatcom system using an adaptive technique,” IEEE Transactions on Smart Grid, vol. 9, no. 5, pp. 3986–3993, Sept 2018.

Wednesday 26 February 2020

A Management of power flow for DC Microgrid with Solar and Wind Energy Sources



ABSTRACT:
Today there is a rapid proliferation of DC loads into the market and DC micro grid with renewable energy sources is emerging as a possible solution to meet growing energy demand. As different energy sources like solar, wind, fuel cell, and diesel generators can be integrated into the DC grid, Management of power flow among the sources is essential. In this paper, a control strategy for Management of power flow in DC micro grid with solar and wind energy sources is presented. As the regulation of voltage profile is important in a standalone system, a dedicated converter is to be employed for maintaining the DC link voltage. DC link voltage is regulated by the battery circuit while maximum power is extracted from Solar and Wind to feed the loads connected at the DC bus. A power flow algorithm is developed to control among three sources in the DC Microgrid. The algorithm is tested for various load conditions and for fluctuations in solar and wind power in MATLAB/SIMULINK environment.
KEYWORDS:

1.      DC microgrid
2.      Power flow administration
3.      Photovoltaics
4.      Wind conversion systems

SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:





Fig. 1 Block diagram of the DC microgrid with Solar and wind energy sources

 EXPERIMENTAL RESULTS:



Fig 2 . Response of the system for increase in load
power





Fig 3. Response of the system for decrease in load power




Fig .4. Response of the system during change in Ppv




Fig .5. Response of the system during change in Pw

 CONCLUSION:
A Management of power flow and control algorithm for DC microgrid with solar and wind energy sources is presented. As the system involves different intermitted energy sources and load whose demand can vary, it is necessary to develop a Management of power flow and control algorithm for the DC Microgrid. To provide ceaseless power supply to the loads and balance the power flow among the different sources at any time, a Management of power flow algorithm is developed. The feasibility of the algorithm has been tested for various load conditions and for  changes in solar and wind power.
REFERENCES:
[1] F. Katiraei, M. R. Iravani, A. L. Dimeas, and N. D. Hatziargyriou, "Microgrids management: control and operation aspects of microgrids, "IEEE Power Energy Mag., vol. 6, no. 3, pp. 54-65, May/Jun. 2008.
[2] W. Jiang and B. Fahimi, “Active current sharing and source  management in fuel cell-battery hybrid power system,” IEEE Trans. Ind. Electron., vol. 57, no. 2, pp. 752–761, Jan. 2010.
[3] L. Xu and D. Chen, "Control and operation of a DC microgrid with variable generation and energy storage," IEEE Trans. Power Del., vol. 26, no. 4, pp. 25 I 3-2522, Oct. 2011.
[4] Jin C, Wang P, Xiao J, "Implementation of hierarchical control in DC microgrids,"IEEE Transaction of Industrial Electronics, vol.61(8), pp.4032-4042,2014.
[5] L. Xiaonan, J. M. Guerrero, S. Kai, and J. C. Vasquez, "An Improved Droop Control Method for DC Microgrids Based on Low Bandwidth Communication With DC Bus Voltage Restoration and Enhanced Current Sharing Accuracy," Power Electronics, IEEE Transactionson,vol.29,pp.1800-1812,2014.

Monday 27 January 2020

Single Phase Bidirectional H6 Rectifier/Inverter



ABSTRACT:
Transformer-less photovoltaic (PV) inverters are more widely adopted due to high efficiency, low cost and light weight, etc. However, H5, HERIC, etc. transformer-less PV inverters do not have the bidirectional capability for solar energy storage system in the future. With topology derivation history reviewed from rectifier to inverter, the essence of bidirectional rectifier/inverter is revealed to find a reverse power flow approach. Therefore, this paper proposes an advanced bidirectional technique for a selected H6 inverter topology with only modulation strategy modified, while the others remain the same. For the H6 circuitry in both rectifier and inverter modes, excellent three level DM voltage feature is achieved, while leakage current issue is eliminated at the same time with improved modulation method. Simulations and experimental results verify the proposed single phase bidirectional H6 rectifier/inverter technique.
KEYWORDS:
1.      H6 inverter
2.      Rectifier
3.      Improved modulation
4.      Bidirectional power flow
5.       Leakage current

SOFTWARE: MATLAB/SIMULINK


CIRCUIT DIAGRAM:




Figure 1 Selected H6 inverter

 EXPERIMENTAL RESULTS:



(a)     Ac grid voltage, ac current, DM voltage and CM voltage in rectifier mode


(b) Switching pulses S1&S4, S2&S3, S5, S6 in rectifier mode


(c) Expanded switching pulses S1&S4, S2&S3, S5, S6 in rectifier mode

(d) Ac grid voltage, ac current, DM voltage and CM voltage in inverter mode

(e) Switching pulses S1&S4, S2&S3, S5, S6 in inverter mode

(f) Expanded switching pulses S1&S4, S2&S3, S5, S6 in inverter mode
Figure 2 Bidirectional H6 rectifier/inverter modulation method simulation Results


(a) Current stress


(b) Voltage stress
Figure 3 H6 rectifier device stress

CONCLUSION:
Aiming solar energy storage system, this paper improves a grid-tied single phase H6 PV inverter from unidirectional power flow to bidirectional power flow. A unified hybrid modulation method is proposed for both rectifier and inverter modes. The main advantages of the proposed solution can be summarized as:
1) Compared with the traditional hybrid modulation method for power rejection to grid only, a simple modification in the switching patterns is just needed for solar energy storage system with H6 type topology.
2) Battery storage is adopted for emergency usage in small solar energy storage system. Therefore, a slight cost of efficiency decreases in rectifier mode due to the partly used body diodes is acceptable, and the excellent DM/CM voltage features of the H6 circuitry in both rectifier and inverter modes are totally achieved.
3) The improved hybrid modulation method would be easily modified and applied to other H6 and similar topologies.
REFERENCES:
[1] R. Teodorescu, M. Liserre, and P. Rodriguez, Grid converters for photovoltaic and wind power systems. Hoboken, NJ, USA: Wiley, 2011.
[2] Rik W. De Doncker. Power Electronics – key enabling technology for a CO2 neutral electrical energy supply. Available: http://www.ifeec.tw/rik.html
[3] Generators connected to the low-voltage distribution network. Available: https://www.vde-verlag.de/standards/0105029/vde-ar-n-4105- anwendungsregel-2011-08.html.
[4] T. Kerekes, R. Teodorescu, P. Rodriguez, G. Vazquez, and E. Aldabas, "A  new high-efficiency single-phase transformerless PV inverter topology, " IEEE Trans. Ind. Electron., vol. 58, no. 1, pp. 184-191, 2011.
[5] R. Bojoi, L. R. Limongi, D. Roiu, and A. Tenconi, "Enhanced power quality control strategy for single-phase inverters in distributed generation systems," IEEE Trans. Power Electron., vol. 26, no. 3, pp. 798–806, 2011.