A Novel Multilevel Inverter Based onSwitched DC Source

ABSTRACT:

This paper presents a multilevel inverter that has been conceptualized to reduce component count, particularly for a large number of output levels. It comprises floating input dc sources alternately connected in opposite polarities with one another through power switches. Each input dc level appears in the stepped load voltage either individually or in additive combinations with other input levels. This approach results in reduced number of power switches as compared to classical topologies. The working principle of the proposed topology is demonstrated with the help of a single-phase five-level inverter. The topology is investigated through simulations and validated experimentally on a laboratory prototype. An exhaustive comparison of the proposed topology is made against the classical cascaded H-bridge topology.

KEYWORDS:

1.      Classical topologies

2.      Multilevel inverter (MLI)

3.      Pulse width modulation (PWM)

4.      Reduced component count

5.      Total harmonic distortion (THD)

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

 As MLIs are gaining interest, efforts are being directed toward reducing the device count for increased number of output levels. A novel topology for MLIs has been proposed in this paper to reduce the device count. The working principle of the proposed topology has been explained, and mathematical formulations corresponding to output voltage, source currents, voltage stresses on switches, and power losses have been developed. Simulation studies performed on a five-level inverter based on the proposed structure have been validated experimentally. Comparison of the proposed topology with conventional topologies reveals that the proposed topology significantly reduces the number of power switches and associated gate driver circuits. Analytical comparisons on the basis of losses and switch cost indicate that the proposed topology is highly competitive. The proposed topology can be effectively employed for applications where isolated dc sources are available. The advantage of the reduction in the device count, however, imposes two limitations: 1) requirement of isolated dc sources as is the case with the CHB topology and 2) curtailed modularity and fault-tolerant capabilities as compared to the CHB topology

REFERENCES:

[1] S. Kouro, M. Malinowski, K. Gopakumar, J. Pou, L. Franquelo, B. Wu, J. Rodriguez, M. Perez, and J. Leon, “Recent advances and industrial applications of multilevel converters,” IEEE Trans. Ind. Electron., vol. 57, no. 8, pp. 2553–2580, Aug. 2010.

[2] G. Buticchi, E. Lorenzani, and G. Franceschini, “A five-level single-phase grid-connected converter for renewable distributed systems,” IEEE Trans. Ind. Electron., vol. 60, no. 3, pp. 906–918, Mar. 2013.

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

[4] S. De, D. Banerjee, K. Siva Kumar, K. Gopakumar, R. Ramchand, and C. Patel, “Multilevel inverters for low-power application,” IET Power Electronics, vol. 4, no. 4, pp. 384–392, Apr. 2011.

[5] M. Malinowski, K. Gopakumar, J. Rodriguez, and M. A. Pérez, “A surveyon cascaded multilevel inverters,” IEEE Trans. Ind. Electron., vol. 57,no. 7, pp. 2197–2206, Jul. 2010.

Analysis and Design of a Standalone Electric Vehicle Charging Station Supplied by Photovoltaic Energy

ABSTRACT:

Nowadays, there is a great development in electric vehicle production and utilization. It has no pollution, high efficiency, low noise, and low maintenance. However, the charging stations, required to charge the electric vehicle batteries, impose high energy demand on the utility grid. One way to overcome the stress on the grid is the utilization of renewable energy sources such as

photovoltaic energy. The utilization of standalone charging stations represents good support to the utility grid. Nevertheless, the electrical design of these systems has different techniques and is sometimes complex. This paper introduces a new simple analysis and design of a standalone charging station powered by photovoltaic energy. Simple closed-form design equations are derived, for all the system components. Case-study design calculations are presented for the proposed charging station. Then, the system is modeled and simulated using Matlab/Simulink platform. Furthermore, an experimental setup is built to verify the system physically. The experimental and simulation results of the proposed system are matched with the design calculations. The results show that the charging process of the electric vehicle battery is precisely steady for all the PV insolation disturbances. In addition, the charging/discharging of the energy storage battery responds perfectly to store and compensate for PV energy variations.

KEYWORDS:

1.      Electric vehicle

2.      Charging station;

3.      Photovoltaic

4.      Maximum power point tracking

SOFTWARE: MATLAB/SIMULINK

 CONCLUSION:

 An isolated EV charging station based on a PV energy source is proposed. The system consists of PV panel, boost converter, ESS batteries, two DC/DC charging converters, and an EV battery. The control system consists of three controllers named the MPPT, the EV charger, and the storage converter controller. PI voltage and current controllers are adapted to control charging/discharging of the ESS system and the EV charger as well. The system is simulated and implemented physically. A single-chip PIC18F4550 microcontroller is utilized to realize the system controllers. New simple energy and power analyses procedure has been introduced. Hence, closed-form equations have been derived to help in the design phase. Complete design of the system, including the ESS size, the PV rating, and the filter components, has been proposed. Simulation and experimental results are very close and verify the effectiveness of the proposed system. At different insolation levels, the results show that the charging process of the EV battery is steady without any disturbance. However, the charging/discharging of the ESS battery responds perfectly to store and compensate for PV energy variations. The current and voltage controllers of the converters give good responses and track their references well. In addition, the MPPT controller tracks the peak conditions of the PV precisely.

 REFERENCES:

1. Irle, R. Global EV Sales for the 1st Half of 2019. EV Volumes. 2019. Available online: http://www.ev-volumes.com/country/ total-world-plug-in-vehicle-volumes/ (accessed on 20 November 2019).

2. Sun, X.; Li, Z.;Wang, X.; Li, C. Technology Development of Electric Vehicles: A Review. Energies 2020, 13, 90. [CrossRef]

3. Luc, Vehicles & Charging Tips. Fastned. 2019. Available online: https://support.fastned.nl/hc/en-gb/sections/115000180588 -Cars-charging-tips- (accessed on 30 March 2019).

4. Richard, L.; Petit, M. Fast charging station with a battery storage system for EV: Optimal integration into the grid. In Proceedings of the 2018 IEEE Power & Energy Society General Meeting (PESGM), Portland, OR, USA, 5–10 August 2018; pp. 1–5.

5. Chakraborty, S.; Vu, H.-N.; Hasan, M.M.; Tran, D.-D.; Baghdadi, M.E.; Hegazy, O. DC-DC Converter Topologies for Electric Vehicles, Plug-in Hybrid Electric Vehicles and Fast Charging Stations: State of the Art and Future Trends. Energies 2019, 12, 1569. [CrossRef]

Electric Vehicle Charging System with PV Grid-Connected Configuration

ABSTRACT:

This paper presents an experimental control strategy of electric vehicle charging system composed of photovoltaic (PV) array, converters, power grid emulator and programmable DC electronic load that represents Li-ion battery emulator. The designed system can supply the battery at the same time as PV energy production. The applied control strategy aims to extract maximum power from PV array and manages the energy flow through the battery with respect to its state of charge and taking into account the constraints of the public grid. The experimental results, obtained with a dSPACE 1103 controller board, show that the system responds within certain limits and confirm the relevance of such system for electric vehicle charging.

KEYWORDS:

1.      Renewable energy integration

2.      Photovoltaic

3.      Battery electric vehicles

4.      Public grid

5.      Control charging system

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

            Smart grid with renewable electricity integrated concerns both the utility companies as well as the end-users. In the next ten years, the smart grid could concern the residential level with house power “routers”, whose goal is to intelligently manage and supply every home appliance by minimizing and redirecting the overall consumption. The prime goal of utility companies could be the real time demand management in order to adjust their electricity generation, for end user it could be the real time control of energy use, like EV charging system.

            An experimental EV charging with PV grid-connected system control strategy was presented. The system control strategy aims to extract maximum power from PV array and manages the energy flow through the BEV, with respect to its SOC. The experimental results are obtained with a numerical modelling implemented under MATLAB-Simulink and a dSPACE 1103 controller board. In this work, a simple and quick to implement control was done. This control was not necessarily developed to improve global energy efficiency or life cycle of the BEV system. For this first approach, the goal was to verify the feasibility of the proposed system control. The results show that the system can supply a BEV at the same time as PV energy production and responds within certain limits of the PV power and public grid availability. Obtained test results indicate that the proposed control can successfully be used for buildings and car parking equipped with PV power plant.

            The further work is the modelling of the behaviour of EV charging with PV grid-connected system as an operating subsystem under the supervision device as a control-command subsystem. The chosen approach will take into account the uncertainties on PV power production, public grid availability and BEV request, in order to achieve more efficient power transfer with a minimized public grid impact.

REFERENCES:

[1] S. D. Jenkins, J. R. Rossmaier, and M. Ferdowsi, "Utilization and effect of plug-in hybrid electric vehicles in the United States power grid", in: Proc. IEEE Vehicle Power and Propulsion Conference, VPPC 2008.

[2] EPRI, “Environmental Assessment of Plug-In Hybrid Electric Vehicles; Volume 1: Nationwide Greenhouse Gas Emissions”, Final Report, July 2007.

[3] V. Marano and G. Rizzoni, “Energy and Economic Evaluation of PHEVs and their Interaction with Renewable Energy Sources and the Power Grid”, in: Proc. IEEE International Conference on Vehicular Electronics and Safety, 2008.

[4] Y. Gurkaynak and A. Khaligh, “Control and Power Management of a Grid Connected Residential Photovoltaic System with Plug-in Hybrid Electric Vehicle (PHEV) Load”, in Proc. IEEE Applied Power Electronics Conference and Exposition, APEC 2009.

[5] X. Li, L. A. C. Lopes, and S. S. Williamson, “On the suitability of plugin hybrid electric vehicle (PHEV) charging infrastructures based on wind and solar energy”, in: Proc. IEEE Power & Energy Society General Meeting, PES 2009

A Commutation Torque Ripple Suppression Strategy for Brushless DC Motor Based on Diode-Assisted Buck-Boost Inverter

ABSTRACT:

Based on diode-assisted buck-boost inverter, this paper proposes a new commutation torque ripple suppression strategy for brushless DC motor (BLDCM). Four types of switching vectors are constructed, according to the working pattern of the diode-assisted inverter and the operation mode of the BLDCM. Moreover, the effects of switching vector combination on commutation torque ripple suppression and motor speed regulation are analyzed in the commutation and normal conduction periods, respectively. Based on this analysis, the duration of switching vectors within each modulation cycle is derived and the sequence of vectors is arranged at the same time in these two periods. The proposed method can effectively suppress the commutation torque ripple over the full speed range by unified switching vectors during the commutation period, without needing to switch control strategies according to the speed range. In addition, the increase of the voltage stress of switching devices in the inverter bridge can be avoided by designing the duration and sequence of switching vectors during the commutation and normal conduction periods. The effectiveness of the presented method is validated by the experimental results.

KEYWORDS:

1. Brushless DC motor

2. Commutation torque ripple reduction

3. Diode-assisted buck-boost inverter

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

In this paper, a new commutation torque ripple suppression strategy is proposed based on the diode-assisted boost-buck inverter. This strategy has the following advantages:

1) The proposed method can effectively improve the utilization of DC supply voltage, and it is promising for the industrial applications supplied by low-voltage DC source such as fuel cell, lithium battery, and photovoltaic array.

2) The commutation torque ripple over the full speed range can be suppressed effectively under the proposed method, without needing to switch control strategies according to the speed range.

3) By designing the duration and sequence of the large vector, small vector and zero vector, the increase of the voltage stress of switching devices in the inverter bridge can be avoided during the commutation and normal conduction periods.

4) Compared with the methods of adding a DC-DC converter, the proposed method can reduce the number of switches and passive devices, which is beneficial to reduce the cost of drive system.

REFERENCES:

[1] R. Krishnan, Permanent magnet synchronous and brushless DC motor drives[M]. CRC Press/Taylor & Francis, 2010.

[2] S. Chen, X. Zhou, G. Bai, K. Wang, et al, “Adaptive commutation error compensation strategy based on a flux linkage function for sensorless brushless DC motor drives in a wide speed range,” IEEE Trans. Power Electron., vol. 33, no. 5, pp. 3752–3764, May. 2018.

[3] A. Lee, C. Fan, and G. Chen, “Current integral method for fine commutation tuning of sensorless brushless DC motor,” IEEE Trans. Power Electron., vol. 32, no.12, pp. 9249–9266, Dec. 2017.

[4] Y. Shen and Z. Q. Zhu, “Investigation of permanent magnet brushless machines having unequal-magnet height pole,” IEEE Trans. Magn., vol. 48, no. 12, pp. 4815–4830, Dec. 2012.

[5] W. Jiang, Y. Liao, J. Wang, and Y. Xie, “Improved control of BLDCM considering commutation torque ripple and commutation time in full speed range,” IEEE Trans. Power Electron., vol. 33, no.5, pp. 4249–4260, May. 2018.

Characteristics Behavior of Shunt DC Electric Spring For Mitigating DC Microgrid Issues

 ABSTRACT:

There is a huge pervasive consideration of integrating renewable energy sources (RES) to DC power system. Most of the modern loads are DC. Photovoltaic (PV) integrated DC microgrids feature remarkable advantages such as providing DC which can be directly utilized in DC grids that eliminates major step of ACDC conversion. However, intermittency of RES and presence of some non- idealistic like voltage fluctuation, droop effect, faults and harmonics causes instability problems in DC microgrid. This leads to voltage weakening, potential blackout and damage to equipment. To deal with inconsistency and improbability of RES new emerging demand side management (DSM) technology has been developed called Electric Spring (ES). ES can be employed in AC or DC grid for supply-demand management. DC Electric Spring (DC-ES) is a unique method of distributed voltage control over traditional single point control by effectively handling supply. This paper comprises one of the types of DC-ES called the shunt DC-ES for voltage regulation and Fault Ride Through (FRT) support with various mode of operation on DC bus. To demonstrate the performance analysis and to alleviate DC microgrid issues, DC-ES is implemented on 48V DC system. Moreover, the detail comprehensive characteristics behavior of shunt DC-ES is presented and validated using MATLAB software.

KEYWORDS:

1.      DC-Electric Spring

2.      DC Microgrid

3.      Fault Ride Through

4.      Renewable energy sources

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

 This paper presents an effective proficiency of shunt DC-ES to fix the CL voltage and to improve Fault Ride Through (FRT) capability of DC system in case of low power DPGS like PV. The comprehensive investigation highlights the characteristics performance of shunt DC-ES for voltage variations during various DC system contingencies without energy consumption. The presented results verifies the successful performance of shunt DC-ES for mitigating different issues in DC microgrids such as voltage regulation and FRT support. It is found that the shunt configuration of DC-ES exactly follows its ideal characteristics with an excellent dynamic response.

REFERENCES:

[1] X. Chen, M. Shi, H. Sun, and H. He “Distributed Cooperative Control and Stability Analysis of Multiple DC Electric Springs in a DC Microgrid,” IEEE Trans. Ind. Electron, vol. 65, no. 7, pp. 5611-5622, July 2018.

[2] N. Hatziargyriou, Microgrids Architecture and Control, 1st ed. Wiley, 2014.

[3] S. Anand, B. G. Fernandes, and M. Guerrero, “Distributed control to ensure proportional load sharing and improve voltage regulation in low voltage DC microgrids,” IEEE Trans. Power Electron., vol. 28, no. 4, pp. 1900–1913, Apr. 2013.

[4] K. T. Mok, M. H. Wang, S. C. Tan, and S.Y.R. Hui, ‘‘DC electric springs -- An emerging technology for DC grids,’’ IEEE Applied Power Electronics and Exposition (APEC), Mar. 2015.

[5] Y. Yang, S. C. Tan, and S.Y.R. Hui, “Enhanced Digital PI Control with state Variable Feedback Loop for DC Electric Springs”, in Proc. IEEE Applied Power Electronics Confernce and Exposition (APEC), March 2017.

Design and simulation of cascaded H-bridge 5-level inverter for grid connection system based on multi-carrier PWM technique

 ABSTRACT:

Cascaded H-Bridge (CHB) multi-level inverter has become attractive in medium voltage and grid connection to improve power quality with high efficiency, and low switching losses. Voltage Oriented Control (VOC) regulates the injected power and the connection between the cascaded H-bridge inverter and the utility grid. In the modulation stage for the VOC, there are several techniques such as Space Vector Pulse Width Modulation (SVPWM), Multi-Carrier Pulse Width Modulation (MCPWM), Selective Harmonic Elimination (SHE) used to obtain gating pulses for the IGBTs switches. In this paper, a three-phase 5-level CHB inverter with a grid connection system is present and the technique of MCPWM is used. A comparative study between each method of (MCPWM) using MATLAB/ Simulink environment has been done on the Total Harmonic Distortion (THD) for inverter phase voltage and current with different injected reference current values. It is found that phase current THD is less with the Phase Shift PWM (PS-PWM) technique.

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

 This paper involves a study and analysis for a three-phase 5-level cascaded H-bridge inverter for grid connection with unity power factor. The system controlled by traditional voltage-oriented control. Carrier shift techniques are used in modulation stag and simulated by MATLAB/Simulink environment. The application of Fast Fourier Transform (FFT) analysis for THD in these techniques shows that the total harmonic distortion for the inverter current by using Phase Shift Pulse Width Modulation (PS-PWM) is small compared with other existing methods. It means that high-quality output current and even high-power distribution are obtained; therefore, this technique is suitable for grid connection.

REFERENCES:

[1] Hasan N S, Rosmin N and Musta H 2017 Reviews on multilevel converter and modulation techniques Renew. Sustain. Energy Rev. 80 163–74

[2] Tarek M S I, Siam A, Zia M and Rahman M M 2018 A novel five-level inverter topology with reactive power control for grid-connected PV system 2018 International Conference on Smart Grid and Clean Energy Technologies, ICSGCE 2018 (IEEE) pp 101–5

[3] Sinha A, Chandra Jana K and Kumar Das M 2018 An inclusive review on different multi-level inverter topologies, their modulation and control strategies for a grid connected photo-voltaic system Sol. Energy 170 633–57

[4] Al-Badrani H, Feuersanger S and Pacas M 2018 VSI with Sinusoidal Voltages for an Enhanced Sensorless Control of the Induction Machine PCIM Europe 2018, Nuremberg, Germany pp 1199– 205

[5] Shanono I H, Rul N, Abdullah H and Muhammad A 2018 A Survey of Multilevel Voltage Source Inverter Topologies , Controls and Applications Int. J. Power Electron. Drive Syst. 9 1186–201

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.