A New Variable Frequency Control of Forty-nine Level Cascaded Packed U-cell Voltage Source Inverter

ABSTRACT:

 Requirement of large number of levels with lower number of switching devices has made asymmetrical converters more popular than the symmetrical ones. Asymmetrical cascaded multilevel inverters (ACMLI) can achieve high efficiency by combining switching devices with different voltage ratings and technologies. The proposed ACMLI cascades two or more units of packed U-Cell (PUC) inverters using two or more isolated DC link supplies. In this paper, one of the PUC unit is controlled using high switching frequency while the other PUCs are operated in a step mode at low switching frequencies, thus operating them in a variable frequency control mode. The cascading of two 7-level PUC inverters with DC link voltage ratios of 1:7 can produce an output voltage with 49 (7x7) levels. The multi-level output voltage waveform is nearly sinusoidal with very low THD content, and the low switching frequency operation leads to lower power dissipation and greater system efficiency. However, each PUC module requires two dc voltage sources. To address this concern, in this manuscript, each PUC module consists of one dc voltage source and one dc bus capacitor. With the cascaded PUC topology and proposed control algorithm, load current and dc bus capacitor voltage control is achieved simultaneously. The proposed converter and its control technique lead to the breaking of the design trade-off rule between switching frequency (efficiency) and filter size. This is very useful in various applications such as Uninterruptible Power Supplies (UPS), and grid-tie inverters. The converter and its control technique are simulated using MATLAB/Simulink software and simulation results for both open loop and closed loop are discussed. Hardware results are obtained by developing a 1-KW experimental prototype. Simulation and experimental results confirm the usefulness and effectiveness of the proposed topology and its control technique. 

KEYWORDS:

1.      Asymmetric cascaded multilevel inverters

2.      Total Harmonic Distortion

3.      Variable frequency control

4.      Packed U-Cell inverters

5.      Low switching frequency

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

This paper presented a cascaded Packed U-Cell inverter with forty-nine output voltage levels offering a reduced switch count solution. Only two auxiliary capacitors along with two isolated dc voltage sources are used to achieve forty-nine levels in the output voltage waveform. Between the two cascaded PUCs, one cell operates at high switching frequency (2 kHz) and other unit is operating at seven time the fundamental frequency (350 Hz). DC link voltage ratio of the two PUCs is kept at 1:7 to achieve the maximum forty-nine level output voltage. Detailed explanation of level formation and individual PUC output voltages are also discussed. Presented control algorithm achieves dc bus capacitor voltage and load current control simultaneously. Simulation results are discussed in detail for both open loop and closed loop performances. Accurate and robust control of dc bus capacitor control is achieved during load current variation as shown in transient response of the system. Experimental results validate voltage levels formation in individual PUC module and formation of resultant 49 – levels in output voltages. THD spectrum of load voltage and load current are also presented (in both simulation and experimental results), which verify the superior THD performance.

REFERENCES:

[1]. J. Rodriguez, J. S. Lai, F. Z. Peng “Multilevel inverters: A survey of topologies, controls, and applications”, IEEE Trans. Ind. Electron.,vol. 49, no. 4, pp. 724–738, 2002.

[2]. L.G. Franquelo, J. Rodriguez, J.I. Leon, S. Kouro, R. Portillo, M.M. Prats, “The age of multilevel converters arrives”, IEEE Ind. Electro. Mag., vol. 2, no. 2, pp. 28–39, Jun. 2008.

[3]. S. Kouro, M. Malinowski, K Gopakumar, J. Pou, L.G Franquelo, B. Wu, J. Rodriguez, M.A. Perez, J.I. Leon, "Recent advances and industrial applications of multilevel converters," IEEE Transactions on Ind. Elect., vol.57, no.8, pp.2553-2580, Aug. 2010.

[4]. A. Nabae, I. Takahashi, and H. Akagi, “A new neutral-point-clamped PWM inverter,” IEEE Trans. Ind. Appl., vol. IA-17, no. 5, pp. 518–523, Sep. 1981.

[5]. S. Payami, R. K. Behera and A. Iqbal, "DTC of Three-Level NPC Inverter Fed Five-Phase Induction Motor Drive with Novel Neutral Point Voltage Balancing Scheme," in IEEE Transactions on Power Electronics, vol. 33, no. 2, pp. 1487-1500, Feb. 2018.

A New 7L-PUC Multi-Cells Modular MultilevelConverter for AC-AC and AC-DC Applications

ABSTRACT:

In this paper, a new cell based Modular Multilevel Converter (MMC) for AC-AC and AC-DC applications is presented. The new topology makes use of an efficient Packed U Cells (PUC) structure to form the Multi-Cells Modular Multilevel Converters (M3C). It is a member of MMC root family, with extended operational capability covering therefore AC-AC and AC-DC modes of operation. A dynamic model of the PUC and the single phase M3C will be used along with predictive control method to validate the effectiveness of different operation modes of the converter.

KEYWORDS:

1.      Modular Multilevel Converter (MMC)

2.      Multi-Cells Modular Multilevel Converters (M3C)

3.      Packed U-Cells

4.      Single phase AC-AC and AC-DC power converter

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

A new efficient multilevel cell topology has been introduced to the M3C family. The increased cell terminal voltage levels bring more smoothness to the arm controlled voltages, thus increasing the voltage levels to component ratio. Wide range of operating modes were tested, showing fast dynamic response to variations in reference signals. Model predictive control proved effectiveness against transient output references and kept good performance with capacitor parameter variations.

REFERENCES:

[1] H. Abu-Rub, M. Malinowski, and K. Al-Haddad, Power Electronics for Renewable Energy Systems, Transportation and Industrial Applications: John Wiley & Sons, 2014.

[2] B. Singh, A. Chandra, and K. Al-Haddad, Power Quality: Problems and Mitigation Techniques: John Wiley & Sons, 2015.

[3] R. Marquardt, "Stromrichterschaltung mit verteilten Energiespeichern und Verfahren zur Steuerung einer derartigen Stromrichterschaltung," Patentschrift DE 101 03 031 B4 Patent, 2001.

[4] A. Lesnicar and R. Marquardt, "A new modular voltage source inverter topology," presented at the European Power Electronics Conference (EPE), Toulouse, France, 2003.

[5] M. Glinka and R. Marquardt, "A new AC/AC multilevel converter family," IEEE Transactions on Industrial Electronics, vol. 52, pp. 662- 669, 2005.

Performance of Grid-Connected PV System Based on SAPF for Power Quality Improvement

ABSTRACT:

This paper presents the design of a shunt Active Power Filter (SAPF) for grid-connected photovoltaic systems. The proposed system injects PV power into the grid, by feeding the SAPF; to eliminate harmonics currents and compensate reactive power produced by nonlinear loads. To inject the photovoltaic power to the grid we use a boost converter controlled by a Fuzzy logic (FLC) algorithm for maximum power point tracking (MPPT). The SAPF system is based on a two-level voltage source inverter (VSI); P-Q theory algorithm is used for references harmonic currents extraction. The overall system is designed and developed using MATLAB /Simulink software. Simulation results confirm the performance of the grid-connected photovoltaic system based on SAPF. For the MPPT controller, the results show that the proposed FLC algorithm is fast in finding the MPPT than conventional techniques used for MPPT like perturbed and observed (P&O). The simulated compensation system shows its effectiveness such as the sinusoidal form of the currents and the reactive power compensation. The proposed solution has achieved a low Total Harmonic Distortion (THD), demonstrating the efficiency of the presented method. Also, the results determine the performances of the proposed system and offer future perspectives of renewable energy for power quality improvement.

KEYWORDS:   

1.      SAPF, Harmonics

2.      MPPT

3.      Reactive power

4.      P-Q theory algorithm

5.      Power quality and THD

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

 The present article presents an analysis and simulation of a three-phase SAPF fed by PV systems. An MPPT fuzzy logic controller is employed to feed the grid by the maximum allowable PV power. The proposed system has been simulated in MATLAB/SIMULINK software. This system is used to eliminate harmonics and to compensate reactive power generated by nonlinear loads. Performances of the shunt APF are related to the current references quality. This method is very important because it allows harmonic currents and reactive power compensation simultaneously. Simulation results show that the current obtained after filtering and the voltage waveforms are in phase. Also, the current THD is reduced from 33.34% to 2.87% which confirms the good filtering quality of harmonic currents and the perfect compensation of reactive power which improve the power quality.

REFERENCES:

[1] J. Lu, X. Xiao, J. Zhang, Y. Lv, and C. Yuan, "A Novel Constant Active-current Limit Coordinated Control Strategy Improving Voltage Sag Mitigation for Modular Multi-level Inverter-based Unified Power Quality Conditioner," Electric Power Components and Systems, vol. 44, pp. 578-588, 2016.

[2] R. Belaidi, A. Haddouche, and H. Guendouz, "Fuzzy logic controller based three-phase shunt active power filter for compensating harmonics and reactive power under unbalanced mains voltages," Energy Procedia, vol. 18, pp. 560-570, 2012.

[3] T.-J. Park, G.-Y. Jeong, and B.-H. Kwon, "Shunt active filter for reactive power compensation," International Journal o Electronics, vol. 88, pp. 1257-1269, 2001.

[4] S. K. Jain, P. Agarwal, and H. Gupta, "A Dedicated Microcontroller based Fuzzy Controlled Shunt Active Power Filter," Intelligent Automation & Soft Computing, vol. 11, pp. 33- 46, 2005.

[5] K. Srikanth, T. K. Mohan, and P. Vishnuvardhan, "Improvement of power quality for microgrid using fuzzy based UPQC controller," in Electrical, Electronics, Signals, Communication and Optimization (EESCO), 2015 International Conference on, 2015, pp. 1-6.

Off-board electric vehicle battery chargerusing PV array

 ABSTRACT:

During the recent decade, the automobile industry is booming with the evolution of electric vehicle (EV). Battery charging system plays a major role in the development of EVs. Charging of EV battery from the grid increases its load demand. This leads to propose a photovoltaic (PV) array-based off-board EV battery charging system in this study. Irrespective of solar irradiations, the EV battery is to be charged constantly which is achieved by employing a backup battery bank in addition to the PV array. Using the sepic converter and three-phase bidirectional DC–DC converter, the proposed system is capable of charging the EV battery during both sunshine hours and non-sunshine hours. During peak sunshine hours, the backup battery gets charged along with the EV battery and during non-sunshine hours, the backup battery supports the charging of EV battery. The proposed charging system is simulated using Simulink in the MATLAB software and an experimental prototype is fabricated and tested in the laboratory and the results are furnished in this study.

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

 

 In this paper, an off-board EV battery charging system fed from PV array is proposed. This paper discusses the flexibility of the system to charge the EV battery constantly irrespective of the irradiation conditions. The system is designed and simulated in Simulink environment of the MATLAB software. The hardware prototype is fabricated and tested in laboratory for the three modes of operation of the proposed charging system separately and the results are furnished. In OPAL-RT Real time simulator OP4500, experimental investigation is carried out in RCP methodology and the dynamic response of the system is furnished both in simulation and experimental investigation. Correlation between the simulation and experimental results emphasise the effectiveness of the proposed charger.

REFERENCES:

[1] Santhosh, T.K., Govindaraju, C.: ‘Dual input dual output power converter with one-step-ahead control for hybrid electric vehicle applications’, IET Electr. Syst. Transp., 2017, 7, (3), pp. 190–200

[2] Shukla, A., Verma, K., Kumar, R.: ‘Voltage-dependent modelling of fast charging electric vehicle load considering battery characteristics’, IET Electr. Syst. Transp., 2018, 8, (4), pp. 221–230

[3] Wirasingha, S.G., Emadi, A.: ‘Pihef: plug-in hybrid electric factor’, IEEE Trans. Veh. Technol., 2011, 60, pp. 1279–1284

[4] Kirthiga, S., Jothi Swaroopan, N.M.: ‘Highly reliable inverter topology with a novel soft computing technique to eliminate leakage current in grid-connected transformerless photovoltaic systems’, Comput. Electr. Eng., 2018, 68, pp. 192–203

[5] Badawy, M.O., Sozer, Y.: ‘Power flow management of a grid tied PV-battery system for electric vehicles charging’, IEEE Trans. Ind. Appl., 2017, 53, pp. 1347–1357

Solar PV Charging Station for Electric Vehicles

ABSTRACT:

Of late, electric vehicles (EVs) have attracted much attention owing to their use of clean energy. Large progress in lithium-ion battery has propelled the development of EVs.However, the challenge is that growing number of EVs leads to huge demand in electric power, which will aggravate the power grid load. This leads to an exploration for alternative and clean sources of energy to charge EVs. This project implements solar energy system to erect a charging station for EV application. The charging station employs multi-port charging by providing a constant voltage DC bus. The charging controllers are operated based on the concept of power balance, and constant current/constant voltage charging. Performance of the charging system is validated with simulation and experimental results.

KEYWORDS:

1.      Electric Vehicles

2.       Solar Power

3.      Charging station

4.      DC-DC converters

5.      MPPT

6.      CCCV battery Charging

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

 Utilization of Optimization techniques in the use of renewable resources like Solar, wind, biofuel will enhance the opportunities of Electric Vehicles. Extension of the system with fast response storage scheme can be implemented for Fast charging stations. Intelligent Controllers or Machine Learning Techniques can be implemented to avoid excess loading of EV Charging stations on the grid. Hybrid charging stations incorporating more than one renewable source or a backup diesel generator will certainly increase the stability and reliability of the system.

 REFERENCES:

 [1] T. S. Biya and M. R. Sindhu, "Design and Power Management of Solar Powered Electric Vehicle Charging Station with Energy Storage System," Proceedings of 3rd International conference on Electronics, Communication and Aerospace Technology (ICECA), Coimbatore, India, 2019.

[2] K. S. Vikas, B. Raviteja Reddy, S. G. Abijith and M. R. Sindhu, "Controller for Charging Electric Vehicles at Workplaces using Solar Energy," Proceedings of International Conference on Communication and Signal Processing (ICCSP), Chennai, India, 2019.

[3] B. Revathi, A. Ramesh, S. Sivanandhan, T. B. Isha, V. Prakash and S. G., "Solar Charger for Electric Vehicles" ,Proceedings of International Conference on Emerging Trends and Innovations In Engineering And Technological Research (ICETIETR), Ernakulam, 2018, pp. 1-4.

[4] D. Oulad-abbou, S. Doubabi and A. Rachid, "Solar charging station for electric vehicles," Proceedings of 3rd International Renewable and Sustainable Energy Conference (IRSEC), Marrakech, 2015.

[5] B. Singh, A. Verma, A. Chandra and K. Al-Haddad, "Implementation of Solar PV-Battery and Diesel Generator Based Electric Vehicle Charging Station," Proceedings of IEEE International Conference on Power Electronics, Drives and Energy Systems (PEDES),2018, Chennai, India.

Electrical design of a photovoltaic-grid system for electric vehicles charging station

ABSTRACT:

This work presents a smart method for a photovoltaic grid system for electric vehicles charging station, however, it describes the flow power through a smooth algorithm using Matlab/Simulink environment. The consumption of electric vehicle battery is considered as a daily load for the charging station, indeed, it is highly recommended to predict the periodic power use in the charging station. However, the storage system is ensured through a lithium ion battery, which provides a wider operating temperature and others convenient characteristics. Additionally, the contribution of the electrical grid is also combined in this architecture as a back-up plan for mutual benefits when the photovoltaic power is unable to secure the station needs, on the one hand and on the other hand, when the battery of the charging station is fully charged and the photovoltaic system is able to inject an extra energy in the grid.

KEYWORDS:

1.      Photovoltaic-Grid System (PVGS)

2.      Electric vehicle (EV)

3.      Charging Station (CS)

4.      dc-dc Converters

5.      Maximum Power Point Tracking (MPPT)

6.      Perturb and Observe (P&O)

SOFTWARE: MATLAB/SIMULINK

 CONCLUSION:

 This paper presents an intelligent process to feed a lithium ion battery in an EVCS architecture. In this regard, the effectiveness of charging the battery through numerous modes of operation has been validated by simulation results, indeed, it is interesting how fast the battery is charging under higher recharge rate. In fact, this work is inspired from a study case of a project with full specifications, for instance, the meteorological data for the PV panels design and the daily need of energy for the EVB to resize the rated capacity of the BSB. However, the contribution of the grid power remains primordial in the structure nonetheless there are some complexity issues related to the used power flow algorithms in the controller unit, and how it effects on the grid, positively and negatively both.

REFERENCES:

 

[1] I. Rahman, P. M. Vasant, B. S. M. Singh, M. Abdullah-Al-Wadud, and N. Adnan, “Review of recent trends in optimization techniques for plug-in hybrid, and electric vehicle charging infrastructures,” Renew. Sustain.Energy Rev., vol. 58, pp. 1039–1047, 2016.

[2] A. R. Bhatti, Z. Salam, M. J. B. A. Aziz, K. P. Yee, and R. H. Ashique, “Electric vehicles charging using photovoltaic: Status and technological review,” Renew. Sustain. Energy Rev., vol. 54, pp. 34–47, 2016.

[3] M. Van Der Kam and W. Van Sark, “Smart charging of electric vehicles with photovoltaic power and vehicle-to-grid technology in a microgrid ; a case study,” Appl. Energy, vol. 152, pp. 20–30, 2015.

[4] J. P. Torreglosa, P. García-Triviño, L. M. Fernández-Ramirez, and F. Jurado, “Decentralized energy management strategy based on predictive controllers for a medium voltage direct current photovoltaic electric vehicle charging station,” Energy Convers. Manag., vol. 108, pp. 1–13, 2016.

[5] P. Goli and W. Shireen, “PV powered smart charging station for PHEVs,” Renew. Energy, vol. 66, pp. 280–287, 2014.

Electric vehicles charging using photovoltaic: Status and technological review

ABSTRACT:

The integration of solar photovoltaic(PV) into the electric vehicle(EV) charging system has been on the rise due to several factors, namely continuous reduction in the price of PV modules, rapid growth in EV and concerns over the effects of green house gases. Despite the numerous review articles published on EV charging using the utility(grid) electrical supply, so far, none has given sufficient emphasis on the PV charger. With the growing interest in this subject, this review paper summarizes and update all the related aspects on PV–EV charging, which include the power converter topologies, charging mechanisms and control for both PV–grid and PV-standalone /hybrid systems. In addition, the future outlook and the challenges that face this technology are highlighted. It is envisaged that the information gathered in this paper will be a valuable one-stop source of information for researchers working in this topic.

KEYWORDS:

1.      Photovoltaic(PV)system

2.      Electric vehicle(EV)charging system

3.      State of charge(SOC)

4.      Maximum power point tracking(MPPT)

5.      MPPT dc–dc converter

6.       Bi-directional Inverter

7.       Bi-directional dc–dc charger

8.       Control algorithm

9.      EV charging algorithm

10.  Prediction models

11.  Optimization techniques

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

 This paper reviews the PV–grid and PV-standalone EV charging methods proposed in various papers .It is noted ,among the two structures, the PV–grid is more popular due to its flexibility and its interruption-less operation . Also in this paper, the main hardware components, i.e. the dc–dc converter with MPPT ,bi-directional inverter and bi-directional dc charger are evaluated. Due to the rapid development, it is not possible to cover all aspects related to the EV charging infra structure in a single work. Other topics—for example , the economic and environmental impacts of PV and grid powered EV charging are addressed elsewhere [9,86]. Further- more, issues such as the stability, reliability and PV–EV interactions require detailed analysis that may not be feasible for inclusion. For the energy management systems, researchers are highly relaying optimization algorithms and soft computing. However ,it seems that the heuristic rule based charging strategies is a good solution for quick and accurate energy management as already been adopted by [92]. But, there is still a need to devise more accurate techniques for better utilization of available PV energy.

REFERENCES:

 [1]Galus MD, Anders son G. Demand management of grid connected plug-in hybrid electric vehicles(PHEV).In: Proceedings of IEEE energy 2030 con- ference,ENERGY;2008.p.1–8.

[2]Kelman C. Supporting increasing renewable energy penetration in Australia- the potential contribution of electric vehicles. In: Proceedings of 20th Australasi an universities power engineering conference (AUPEC);2010.p.1–6. [3] Barker PP, Bing JM. Advances in solar photovoltaic technology :an applications perspective .In :Proceedings of power engineering society general meeting, vol.2;2005.p.1955–60.

[4] KadarP, VargaA. PhotoVoltaic EV chargestation. In: Proceedings ofIEEE11th international symposium on applied machine intelligence and informatics (SAMI);2013.p.57–60.

[5] Branker K, Pathak MJM ,Pearce JM. Are view of solar photovoltaic levelized cost of electricity.  Renew Sustain Energy Rev2011;15:4470–82.