A Modified Seven Level Cascaded H Bridge Inverter

 ABSTRACT:

 Presently Multilevel inverters are extensively used for high-voltage applications and their execution is exceptionally better to that of regular two-level inverters due to minimized harmonic distortion, lower electromagnetic interference and larger DC link voltages. Nevertheless certain shortcomings are faced such as adding in number of components and voltage balancing problem. In order to overcome these, a seven-level hybrid inverter has been proposed. This topology requires a lesser number of power switches which results in the decrease of multifaceted nature, add up to cost and weight of the inverter. Finally this can be able to generate near sinusoidal voltages and approximately fundamental frequency switching. The simulation and the experimental results of a modified cascaded seven level H bridge inverter with and without LC filter are presented for validation.

KEYWORDS:

1.      Cascaded H-bridge inverter (CHBI)

2.      Seven level hybrid inverter

3.      Asymmetrical DC sources

4.      Total harmonic distortion (THD)

5.      Pulse Width modulation (PWM)

6.      Multi-level Inverter (MLI)

7.      Real time Interface (RTI)

SOFTWARE: MATLAB/SIMULINK

 CONCLUSION:

A modified cascaded seven level H-bridge inverter was fabricated which has the benefit of reduced THD, portability, and cost has compared to normal cascaded H-bridge inverter. Since the topology requires minimum switches, and low-cost real time interfacing device (Arduino) compared DSP, DSPACE, FPGA, etc., the overall expenditure for fabrication reduces. This paper envisages the working of proposed structure. An LC filter is introduced which helps in getting nearer to sinusoidal waveform. The concepts which are projected are verified through simulation and experimental results.

REFERENCES:

[1] E. Babaei and S.Hosseini, “Charge balance control methods for asymmetrical cascade multilevel converters”. In Proc. ICEMS, Seoul, Korea, 2007, pp, 74-79.

[2] K. Wang, Y. Li, Z. Zheng, and L. Xu, “Voltage balancing and

fluctuation suppression methods of floating capacitors in a new modular multilevel converter,” IEEE Trans. Ind. Electron., vol. 60, no. 5, pp. 1943–1954,May 2013

[3] J. Napoles, A. J. Watson, and J. J. Padilla, “Selective harmonic mitigation technique for cascaded H-bridge converter with nonequal dc link voltages,” IEEE Trans. Ind. Electron., vol. 60, no. 5, pp. 1963–1971, May 2013.

[4] N. Farokhnia, S. H. Fathi, N. Yousefpoor, and M. K. Bakhshizadeh, “Minimisation of total harmonic distortion in a cascaded multilevel inverter by regulating of voltages dc sources,” IET Power Electron., vol. 5, no. 1, pp. 106–114, Jan. 2012.

[5] S. Mekhilef, M. N. Abdul Kadir, and Z. Salam, “Digital control of three phase three-stage hybrid multilevel inverter,” IEEE Trans. Ind. Informat., vol. 9, no. 2, pp. 719–727, May 2013.

 

Performance Analysis of Grid Connected PV/Wind Hybrid Power System during Variations of Environmental Conditions and Load

 ABSTRACT:

This paper investigates a dynamic modeling, simulation and control of Photovoltaic (PV)-wind hybrid system connected to electrical grid and feeds large plant with critical variable loads. The technique of extracting maximum power point is applied for the hybrid power system to capture maximum power under varying climatic conditions. Moreover, Control strategy for power flow is proposed to supply critical load demand of plant. Modeling and simulation of the proposed hybrid system is performed using matlab-Simulink software. The Dynamic performance of the proposed hybrid system is analyzed under different environmental conditions. The simulation results have proven the effectiveness of the proposed maximum power point tracking (MPPT) strategies in response to rapid variations of weather conditions during the day. Moreover, the results show that when the injected power from hybrid system is larger than critical load power, the excess power will be injected to electrical grid. Otherwise, when injected power is lower than critical power demand, electrical utility grid in cooperated with hybrid power system will supply the critical load power. Moreover, when the injected power from hybrid system is unavailable, load demand is entirely fed by electrical utility.

KEYWORDS:

1.      PV

2.      Wind

3.      Hybrid system

4.      MPPT control

5.      DFIG

6.      Load

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

In this paper, modeling, simulation and control of grid connected photovoltaic-wind hybrid power system have been successfully investigated. The proposed hybrid system consists of two Photovoltaic (PV) stations placed at different locations and one wind farm are integrated into main AC bus and supply large plant with critical variable loads. The incremental conductance MPPT technique is applied for both PV stations to extract maximum power under variations of solar irradiance. Also, an improved MPPT control strategy based on measurement of mechanical power is applied for wind farm to capture the maximum power under changes of wind speed. Moreover, control strategy for power flow is proposed to supply critical load demand of plant. The Dynamic performance of the proposed hybrid system is tested under different environmental conditions such as changes of solar irradiance and wind speed. In addition, the validation of the proposed power flow is evaluated under variation of the critical load demand. The simulation results have proven the robustness of the MPPT control strategies in response to rapid variations in weather conditions during the day. Moreover, the power flow control strategy successfully meets the critical load demand of the plant.

REFERENCES:

[1] R. Benadli and A. Sellami, "Sliding mode control of a photovoltaic-wind hybrid system," in Electrical Sciences and Technologies in Maghreb (CISTEM), 2014 International Conference on, 2014, pp. 1-8.

[2] J. Hossain, N. Sakib, E. Hossain, and R. Bayindir, "Modelling and Simulation of Solar Plant and Storage System: A Step to Microgrid Technology," International Journal of Renewable Energy Research (IJRER), vol. 7, pp. 723-737, 2017.

[3] U. Choi, K. Lee, and F. Blaabjerg, "Power electronics for renewable energy systems: Wind turbine and photovoltaic systems," in Renewable Energy Research and Applications (ICRERA), 2012 International Conference on, 2012, pp. 1-8.

[4] A. B. Oskouei, M. R. Banaei, and M. Sabahi, "Hybrid PV/wind system with quinary asymmetric inverter without increasing DC-link number," Ain Shams Engineering Journal, vol. 7, pp. 579-592, 2016.

[5] H. Laabidi and A. Mami, "Grid connected Wind- Photovoltaic hybrid system," in Energy (IYCE), 2015 5th International Youth Conference on, 2015, pp. 1-8

Integration of Supercapacitor in Photovoltaic Energy Storage: Modelling and Control

 ABSTRACT

Due to the variable characteristics of photovoltaic energy production or the variation of the load, batteries used in storage systems renewable power can undergo many irregular cycles of charge 1 discharge. In turn, this can also have a detrimental effect on the life of the battery and can increase project costs. This paper presents an embedded energy share method between the energy storage system (battery) and the auxiliary energy storage system such as supercapacitors (SC). Supercapacitors are used to improve batteries life and reduce their stresses by providing or absorbing peaks currents as demanded by the load. The photovoltaic cells are connected to DC bus with boost converter and controlled with MPPT  algorithm, Supercapacitors and batteries are linked to the DC bus through the buck-boost converter. The inductive load is connected to the DC bus by a DC-AC converter. The static converters associated with batteries and supercapacitors are controlled by current. The components of the systems are supervised through a block of energy management. The complete model of the system is implemented in MATLAB/Simulink environment. Simulation results are given to show the performance of the proposed control strategy, for the overall system.

KEYWORDS

1.      Photovoltaic

2.      batteries

3.      supercapacitors

4.      DC bus

5.      Energy storage

6.      Energy management

7.      Converters control

SOFTWARE: MATLAB/SIMULINK

CONCLUSION

In this paper, the storage photovoltaic energy by using a combination of Battery-Supercapacitor has been presented. First, the modeling of different components of the system has been addressed. A comparison of different model of SCs is given. Second, a strategy of control and regulation of the DC bus voltage was proposed, to deal with the variation of solar irradiation and/or the variation of the load. This controller gives the better an efficient energy management and ensures continuity of supply by using the methodology that involves a reversible chopper between the batteries and the DC bus and another between the SC and the DC bus to ensure stable voltage on the DC bus of 400V. The three operating scenarios show that the proposed control and management strategies of DC bus are effective and able to supply desired power. It is also shown that SCs can absorb rapid changes in current to reduce the stress on batteries.

REFERENCES

[1] L. Peiwen, "Energy storage is the core of renewable technologies," Nanotechnol. Mag., vol. 2, no. 4, pp. 13-18, Dec. 2008.

[2] Q. Liyan and Q. Wei, "Constant power control of DFTG wind turbines with supercapacitor energy storage," iEEE Trans. Ind. Appl., vol. 47, no. I, pp. 359-367, Jan. 2011.

[3] M. Uzunoglu and M. S. Alam, "Dynamic modeling, design, and simulation of a combined PE M fuel cell and ultracapacitor system for stand-alone residential applications," IEEE Trans. Energy Convers., vol. 21,no. 3,pp. 767-775,Sep. 2006.

[4] B. P. Roberts and C. Sandberg,'The role of energy storage in development of smart grids," Proc. IEEE, vol. 99, no. 6, pp. 1139-1144, June. 2011.

[5] A Khaligh and L. Zhihao, "Battery, ultracapacitor, fuel cell, and hybrid energy storage systems for electric, hybrid electric, fuel cell, and plugin hybrid electric vehicles: State-of-the -art," IEEE Trans. Veh. Technol, vol. 59, no. 6, pp. 2806-2814, Jully. 2010.

Management and Control of Storage Photovoltaic Energy Using Battery-Supercapacitor Combination

 ABSTRACT

Due to the variable characteristics of photovoltaic energy production, batteries used in storage systems renewable power can undergo many irregular cycles of charge I discharge. In turn, this can also have a detrimental effect on the life of the battery and can increase project costs. This paper presents a study of the storage of photovoltaic energy by using a hybrid batteries-Supercapacitors system. Supercapacitors are used to improve batteries life and reduce their stresses. The photovoltaic cells are connected to DC bus (400V) with boost converter and controlled with MPPT algorithm, Supercapacitors and batteries are linked to the DC bus through the buck-boost converter. The inductive load is connected to the DC bus by a DC-AC converter. The static converters associated with batteries and supercapacitors are controlled by current. The components of the systems are supervised through a block of energy management. The complete model of the system is implemented in MATLAB/Simulink environment. Some simulation results prove the effectiveness of the proposed control strategy.

KEYWORDS

1.      Photovoltaic, batteries

2.      Supercapacitors

3.      DC bus

4.      Energy storage

5.      Energy management

6.      Converters control

SOFTWARE: MATLAB/SIMULINK

 CONCLUSION

This paper presents the storage photovoltaic energy by using a combination of Battery-Supercapacitor. Batteries provide energy storage for a relatively long duration, while SCs can absorb rapid changes in current to reduce the stress on batteries. The proposed strategy concerned the regulation of the DC bus voltage for different sources: Photovoltaic, battery and Supercapacitor, despite the variation of solar irradiation. This enabled an efficient energy management and ensures continuity of supply. Simulation results show that the  proposed control and mangement strategies of DC bus are effective and able to supply desired power .

REFERENCES

[I] L. Peiwen, "Energy storage is the core of renewable technologies, " Nanotechnol. Mag., vol. 2, no. 4, pp. 13-18, Dec. 2008.

[2] Q. Liyan and Q. Wei, "Constant power control of DFiG wind turbines with supercapacitor energy storage, " iEEE Trans. Ind. Appl., vol. 47, no. I, pp. 359-367, Jan. 2011.

[3] M. Uzunoglu and M. S. A1am, "Dynamic modeling, design, andsimulation of a combinedPEM fuel cell and ultracapacitor system for stand-alone residential applications, " iEEE Trans. Energy Convers., vol. 21, no. 3, pp. 767-775, Sep. 2006.

[4] B. P. Roberts and C. Sandberg, 'The role of energy storage in development of smart grids, " Proc. iEEE, vol. 99, no. 6, pp. 1139-1144, June. 2011.

[5] A. Khaligh and L. Zhihao, "Battery, ultracapacitor, fuel cell, and hybrid energy storage systems for electric, hybrid electric, fuel cell, and plugin hybrid electric vehicles: State-of-the -art, " iEEE Trans. Veh. Technol, vol. 59, no. 6, pp. 2806-2814, Jully. 2010.

Integration of PV, Battery and Supercapacitor inIslanded Microgrid

ABSTRACT

Nowadays battery is used to stabilize the DC bus voltage but battery has low power density and high energy density. Whereas the supercapacitor has high power density but low energy density. So, for high energy and power density the integration of battery and supercapacitor is more efficient. It is more challenging to integrate the different sources. So it is required a control strategy to integrate the battery and supercapacitor and provide continuous power to the load. It has also shown that the battery and supercapacitor charged in access mode of power and discharged in deficit mode of power. In this paper proposed a new approach to control the power and dc bus voltage.

KEYWORDS

1.      Battery

2.      MPPT Controller

3.      Photo Voltaic Cell

4.      Supercapacitor

SOFTWARE: MATLAB/SIMULINK

CONCLUSION

In this paper proposed controller is used for proper sharing of power between different energy sources. Here LPF is used to differentiate between the average power supplied by battery and transient power supplied by supercapacitor. Now, new scheme of converter is able to deal with fluctuation of voltage. The constant power and constant voltage across load were observed.

 REFERENCES

[1] U. Manandhar et al., “Energy management and control for grid connected hybrid energy storage system under different operating modes,” IEEE Trans. Smart Grid, vol. 10, no. 2, pp. 1626–1636, 2019.

[2] B. H. Nguyen, R. German, J. P. F. Trovao, and A. Bouscayrol, “Real-time energy management of battery/supercapacitor electric vehicles based on an adaptation of pontryagin’s minimum principle,” IEEE Trans. Veh. Technol., vol. 68, no. 1, pp. 203–212, 2019.

[3] Z. Cabrane, M. Ouassaid, and M. Maaroufi, “Battery and supercapacitor for photovoltaic energy storage: A fuzzy logic management,” IET Renew. Power Gener., vol. 11, no. 8, pp. 1157– 1165, 2017.

[4] H. R. Pota, M. J. Hossain, M. A. Mahmud, and R. Gadh, “Control for microgrids with inverter connected renewable energy resources,” IEEE Power Energy Soc. Gen. Meet., vol. 2014-October, no. October, pp. 27–31, 2014.

[5] S. Angalaeswari, O. V. G. Swathika, V. Ananthakrishnan, J. L. F. Daya, and K. Jamuna, “Efficient Power Management of Grid operated MicroGrid Using Fuzzy Logic Controller (FLC),” Energy Procedia, vol. 117, pp. 268–274, 2017.

 

Modelling and Simulation of Standalone PV Systems with Battery supercapacitor Hybrid Energy Storage System for a Rural Household

 ABSTRACT

This paper presents the comparison between the standalone photovoltaic (PV) system with battery-supercapacitor hybrid energy storage system (BS-HESS) and the conventional standalone PV system with battery-only storage system for a rural household. Standalone PV system with passive BS-HESS and semi-active BS-HESS are presented in this study. Two control strategies, Rule Based Controller (RBC) and Filtration Based Controller (FBC), are developed for the standalone PV system with semi-active BS-HESS with the aim to reduce the battery stress and to extend the battery lifespan. The simulation results show that the system with semi-active BS-HESS prolongs the battery lifespan by significantly reducing the battery peak current up to 8.607% and improving the average SOC of the battery up to 0.34% as compared to the system with battery-only system.

KEYWORDS

1.      Renewable energy

2.      PV

3.      Hybrid energy storage system

4.      Supercapacitor

5.      Battery

6.      Control strategy

SOFTWARE: MATLAB/SIMULINK

CONCLUSION

The BS-HESS shows the positive impact to the battery and the overall system. The passive BS-HESS is easy to be implemented, but the improvement is not significant as it cannot be controlled. Therefore, semi-active BS-HESS is a better configuration that improves the battery lifespan and maximizes the level of utilization of the supercapacitor. The system with semi-active BS-HESS (moving average filter) has significantly smoothened the battery current. The system with semi-active BS-HESS (RBC) shows a great capability in battery peak current reduction and the prevention of battery deep discharge by reducing the peak power demand by 8.607% and improving the average SOC of the battery by 0.34% as compared to the system with battery-only system.

REFERENCES

[1] Kan SY, Verwaal M, and Broekhuizen H, The use of battery-capacitor combinations in photovoltaic powered products, J. Power Sources 2006, 162: 971–974.

[2] Chong LW, Wong YW, Rajkumar RK, Rajkumar RK, and Isa D, Hybrid energy storage systems and control strategies for stand-alone renewable energy power systems, Renew. Sustain. Energy Rev. 2016, 66, pp: 174–189.

[3] Kuperman A and Aharon I, Battery-ultracapacitor hybrids for pulsed current loads: A review, Renew. Sustain. Energy Rev. 2011, 15: 981– 992.

[4] Dougal RA, Liu S, and White RE, Power and life extension of battery-ultracapacitor hybrids, IEEE Trans. Components Packag. Technol 2002., 25: 120–131.

[5] Kuperman A, Aharon I, Malki S, and Kara A, Design of a semiactive battery-ultracapacitor hybrid energy source, IEEE Trans. Power Electron.2013, 28: 806–815.

Modeling, Implementation and Performance Analysis of a Grid-Connected Photovoltaic/Wind Hybrid Power System

ABSTRACT

This paper investigates dynamic modeling, design and control strategy of a grid-connected photovoltaic (PV)/wind hybrid power system. The hybrid power system consists of PV station and wind farm that are integrated through main AC-bus to enhance the system performance. The Maximum Power Point Tracking (MPPT) technique is applied to both PV station and wind farm to extract the maximum power from hybrid power system during variation of the environmental conditions. The modeling and simulation of hybrid power system have been implemented using Matlab/Simulink software. The effectiveness of the MPPT technique and control strategy for the hybrid power system is evaluated during different environmental conditions such as the variations of solar irradiance and wind speed. The simulation results prove the effectiveness of the MPPT technique in extraction the maximum power from hybrid power system during variation of the environmental conditions. Moreover, the hybrid power system operates at unity power factor since the injected current to the electrical grid is in phase with the grid voltage. In addition, the control strategy successfully maintains the grid voltage constant irrespective of the variations of environmental conditions and the injected power from the hybrid power system.

KEYWORDS

1.      PV

2.      Wind

3.      Hybrid system

4.      Wind turbine

5.      DFIG

6.      MPPT control

SOFTWARE: MATLAB/SIMULINK

CONCLUSION

In this paper, a detailed dynamic modeling, design and control strategy of a grid-connected PV/wind hybrid power system has been successfully investigated. The hybrid power system consists of PV station of 1MW rating and a wind farm of 9 MW rating that are integrated through main AC-bus to inject the generated power and enhance the system performance. The incremental conductance MPPT technique is applied for the PV station to extract the maximum power during variation of the solar irradiance. On the other hand, modified MPPT technique based on mechanical power measurement is implemented to capture the maximum power from wind farm during variation of the wind speed. The  effectiveness of the MPPT techniques and control strategy for the hybrid power system is evaluated during different environmental conditions such as the variations of solar irradiance and wind speed. The simulation results have proven the validity of the MPPT techniques in extraction the maximum power from hybrid power system during variation of the environmental conditions. Moreover, the hybrid power system successfully operates at unity power factor since the injected reactive power from hybrid power system is equal to zero. Furthermore, the control strategy successfully maintains the grid voltage constant regardless of the variations of environmental conditions and the injected power from the hybrid power system.

REFERENCES

[1] H. Laabidi and A. Mami, "Grid connected Wind-Photovoltaic hybrid system," in 2015 5th International Youth Conference on Energy (IYCE), pp. 1-8,2015.

[2] A. B. Oskouei, M. R. Banaei, and M. Sabahi, "Hybrid PV/wind system with quinary asymmetric inverter without increasing DC-link number," Ain Shams Engineering Journal, vol. 7, pp. 579-592, 2016.

[3] R. Benadli and A. Sellami, "Sliding mode control of a photovoltaic-wind hybrid system," in 2014 International Conference on Electrical Sciences and Technologies in Maghreb (CISTEM), pp. 1-8, 2014.

[4] A. Parida and D. Chatterjee, "Cogeneration topology for wind energy conversion system using doubly-fed induction generator," IET Power Electronics, vol. 9, pp. 1406-1415, 2016.

[5] B. Singh, S. K. Aggarwal, and T. C. Kandpal, "Performance of wind energy conversion system using a doubly fed induction generator for maximum power point tracking," in Industry Applications Society Annual Meeting (IAS), 2010 IEEE, 2010, pp. 1-7.