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 have many irregular cycles of charge 1 discharge. In turn, this can also have a disadvantageous effect on the life of the battery and can increase project costs.

Supercapacitors

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 captivating peaks currents as order 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 combine with batteries and supercapacitors are controlled by current.

MATLAB

The components of the systems are directed 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 work 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 given. 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 glow and/or the variation of the load.

This controller gives the better an efficient energy management and ensures continuity of supply by using the methods 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.

DC BUS

The three operating scenarios show that the proposed control and management method of DC bus are effective and able to supply want 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 in Islanded 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.

Power Quality Assessment of Voltage Positive Feedback Based Islanding Detection Algorithm

ABSTRACT

Islanding refers to a condition where distributed generators (DGs) inject power solely to the local load after electrical separation from power grid. Several islanding detection methods (IDMs) categorized into remote, active, and passive groups have been reported to detect this undesirable state. In active techniques, a disturbance is injected into the DG’s controller to drift a local yardstick out of the permissible range.

Although this disturbance leads to more effective detections even in well-balanced island, it raises the total harmonic distortion (THD) of the output current under the normal operation conditions. This paper analyzes the power quality aspect of the modified sliding mode controller as a new active IDM for grid-connected photovoltaic system (GCPVS) with a string inverter. Its performance is compared with the voltage positive feedback (VPF) method, a well-known active IDM.

This evaluation is carried out for a 1 kWp GCPVS in MATLAB/Simulink platform by measuring the output current harmonics and THD as well as the efficiency under various penetration and disturbance levels. The output results demonstrate that since the proposed disturbance changes the amplitude of the output current, it does not generate harmonics/subharmonics. Thereby, it has a negligible adverse effect on power quality. It is finally concluded that the performance of the sliding mode-based IDM is reliable from the standpoints of islanding detection and power quality.

KEYWORDS

  1. Islanding detection method (IDM)
  2. Power quality
  3. Sliding mode controller
  4. Total harmonic distortion (THD)
  5. Voltage positive feedback (VPF)

SOFTWARE: MATLAB/SIMULINK

CONCLUSION

In this paper, the influence of the classic VPF and modified sliding-mode IDM on the GCPVS’s power quality and efficiency has been evaluated. The study has been done for a 1 kWp PV system with string inverter. The simulation results show that, while the THD of output current in the proposed IDM is smaller than the simple VPF, both methods render acceptable power quality in a wide range of system operation.

This proper performance has been achieved due to the variation of the current magnitude rather than the angle or frequency. This magnitude variation is realized in VPF and the proposed method in the current and voltage control loops (MPPT), respectively. The simulations also confirm that the acceptable THDI and harmonics are guaranteed in multi-GCPVSs connection situation even at low power generation levels as the worst scenario.

Since the new technique tries to deviate the system from its MPP condition, the effect of embedded disturbance on the efficiency is also performed. In this regard, the simulations are carried out and a negligible reduction in MPPT and inverter efficiencies (less than 0.04%) has been demonstrated in the proposed method. This occurs since MPP can be gained at a small bound around ref. It has been finally concluded that the modified sliding mode controller has the advantages of the conventional VPF scheme in islanding detection as well as a higher power quality in the production of energy.

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.

Five-Level Reduced-Switch-Count Boost PFC Rectifier with Multicarrier PWM

ABSTRACT

A multilevel boost PFC (Power Factor Correction) rectifier is presented in this paper controlled by cascaded controller and multicarrier pulse width modulation technique. The presented topology has less active semiconductor switches compared to similar ones reducing switching losses as well as the number of required gate drives that would shrink manufactured box significantly.

A simple controller has been implemented on the studied converter to generate a constant voltage at the output while generating a five-level voltage waveform at the input without connecting the load to the neutral point of the DC bus capacitors. Multicarrier PWM technique has been used to produce switching pulses from control signal.

Multi-level voltage waveform harmonics has been analyzed comprehensively which affects the size of input current and required filters directly. Full simulation and experimental results confirm the good dynamic performance of the proposed five-level PFC boost rectifier in delivering power from AC grid to the DC loads while correcting the power factor at the AC side as well as reducing the current harmonics remarkably.

KEYWORDS

  1. Multilevel Converter
  2. Active Rectifier
  3. Multicarrier PWM
  4. Cascaded Control
  5. Power Quality

SOFTWARE: MATLAB/SIMULINK

CONCLUSION

In this paper a reduced switch count 5-level boost PFC rectifier has been presented. A cascaded PI controller has been designed to regulate the output DC voltage and to ensure the unity power factor mode of the input AC voltage and current. Moreover, low harmonic AC current waveform has been achieved by the implemented controller and employing a small inductive filter at the input line.

One of the main issues of switching rectifiers is the high switching frequency that has been reduced in this work using PWM technique through adopting multicarrier modulation scheme.Moreover, DC capacitors middle point has not been connected to the load that had required splitting the load to provide a neutral point.

Using a single load with no neutral point makes this topology practical in realistic applications. Comprehensive simulations cases including change in the load, AC voltage fluctuation and generating different DC voltage values have been analysed and performed to ensure the good dynamic performance of the rectifier, adopted controller and switching technique.

REFERENCES

[1] B. Singh, B. N. Singh, A. Chandra, K. Al-Haddad, A. Pandey, and D. P. Kothari, “A review of single-phase improved power quality ACDC converters,” Industrial Electronics, IEEE Transactions on, vol. 50, pp. 962-981, 2003.

[2] B. Singh, B. N. Singh, A. Chandra, K. Al-Haddad, A. Pandey, and D. P. Kothari, “A review of three-phase improved power quality AC-DC converters,” Industrial Electronics, IEEE Transactions on, vol. 51, pp. 641-660, 2004.

[3] H. Abu-Rub, J. Holtz, J. Rodriguez, and G. Baoming, “Mediumvoltage multilevel converters—State of the art, challenges, and requirements in industrial applications,” IEEE Trans. Ind. Electron., vol. 57, pp. 2581-2596, 2010.

[4] H. Abu-Rub, M. Malinowski, and K. Al-Haddad, Power electronics for renewable energy systems, transportation and industrial applications: John Wiley & Sons, 2014.

[5] L. Yacoubi, K. Al-Haddad, L.-A. Dessaint, and F. Fnaiech, “A DSPbased implementation of a nonlinear model reference adaptive control for a three-phase three-level NPC boost rectifier prototype,” Power Electronics, IEEE Transactions on, vol. 20, pp. 1084-1092,

2005.

Voltage and Frequency Control of a Stand-alone Wind-Energy Conversion System Based on PMSG

ABSTRACT:

This paper presents a control strategy for a standalone wind-energy conversion system using Permanent Magnet Synchronous Generator (PMSG). The presented control strategy aims at regulating the load voltage in terms of magnitude and frequency under different operating conditions including wind speed variation, load variation and the unbalanced conditions. The wind generating-system under study consists of a wind turbine, PMSG, uncontrolled rectifier, DC-DC boost converter and voltage source inverter. The presented control strategy is based firstly upon controlling the duty cycle of the boost converter in order to convert the variable input dc-voltage, due to different operating conditions, to an appropriate constant dc voltage. Hence, a sinusoidal pulse width modulated (SPWM) inverter is used to regulate the magnitude and frequency of the load voltage via controlling the modulation index. In order to verify the performance of the employed wind generating-system, a sample of simulation results is obtained and analyzed. The presented simulation results show the effectiveness of the employed control strategy to supply the load at constant voltage and frequency under different operating conditions.

KEYWORDS:

  1. Wind turbine
  2. PMSG
  3. Voltage and frequency control

SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

This paper has presented a control strategy of a stand-alone wind-driven Permanent Magnet Synchronous Generator (PMSG) in order to regulate the magnitude and frequency of the load voltage under different operating conditions. In order to ensure the validity of the presented control strategy, the performance characteristics of the wind-generating system has been studied and discussed under three different operating conditions; wind-speed variation, load variation and unbalance operating condition. The presented simulation results have verified the effectiveness of the control strategy to maintain the load voltage and frequency at a constant level under different operating conditions. This has been achieved by controlling the duty cycle of the employed DC-DC boost converter in order to maintain the DC-link voltage constant at a predetermined value. In addition, the magnitude and frequency of the load voltage has been maintained constant via controlling the modulation index of the load-side SPWM inverter. A constant modulation index has been used in the case of balanced loading conditions. However, different modulation index for each phase has been used in case of unbalanced loading conditions.

REFERENCES:

[1] Aditya Venkataraman, Ali Maswood, Nirnaya Sarangan, Ooi H.P. Gabriel “An Efficient UPF Rectifier for a Stand-Alone Wind Energy Conversion System,” IEEE Trans. on industry applications, vol. 50, NO.2, Marsh/April. 2014

[2] Y. Izumi, A. Pratap, K. Uchida, A. Uehara, T. Senjyu, A. Yona, “A control method for maximum power point tracking of a PMSG-based WECS using online parameter identification of wind turbine,” Proc. Of the IEEE 9th International Conf. on Power Electronics and Drives Systems, Singapore, 5–8 Dec. 2011, pp. 1125–1130.

[3] M. Singh, A. Chandra, B. Singh, “Sensorless power maximization of PMSG based isolated wind-battery hybrid system using adaptive neuro fuzzy controller,” IEEE Ind. Appl. Soc. Annual Meeting, 2010, pp. 1-6.

[4] Nishad Menddis, Kashem M. Muttaqi, Sarath Perara “Management of Battery-Supercapacitor Hybrid Energy Storage and Synchronous Condenser for Isolated Operation of PMSG Based Variable-speed wind Turbine Generating Systems“IEEE Trans. ON SMART GRID, vol. 5, NO.2, MARCH 2014

[5] Luminita BAROTE, Corneliu MARINESCU “Modeling and Operational Testing of an Isolated Variable Speed PMSG Wind Turbine with Battery Energy Storage,” Advances in Electrical and Computer Engineering, vol. 12, No. 2, 2012. For equivalent circuit of PMSG

PMSG Wind Turbine System for Residential Applications

ABSTRACT:

This paper analyzes the operation of small wind turbine system with variable speed Permanent Magnet Synchronous Generator (PMSG) and a Lead Acid Battery (LAB) for residential applications, during wind speed variation. The main purpose is to supply 230 V/50 Hz domestic appliances through a single-phase inverter. The required power for the connected loads can be effectively delivered and supplied by the proposed wind turbine and energy storage systems with an appropriate control method.

The models of the PMSG, boost converter with a control method for obtaining maximum power characteristic of wind turbine (MPPT), voltage source inverter (VSI) and LAB model with battery state of charge (SOC) control method, are presented. Energy storage devices are required for power balance and power quality in stand alone wind energy systems. Simulations and experimental results validate the stability of the supply.

 KEYWORDS:

  1. Wind energy
  2. Variable-speed
  3. Permanent magnets generators and energy storage

 SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

In this paper, a PMSG wind turbine system for residential applications is analyzed. Simulation and experimental results show that the active power balance of the system proves to be satisfying during variable wind speed condition. The MPPT algorithm will ensure a maximum extraction of energy from the available wind.

LAB always ensures the safe supply of the loads (households) regardless of the problems caused by wind speed variations. At the end one can conclude that the power system’s stability considered in terms of load power quality can be ensured by using the proposed configuration.

REFERENCES:

[1] Barton, J.P.; Infield, D.G.: Energy storage and its use with intermittent renewable energy, IEEE Transaction on Energy Conversion, vol.19, no.2, June 2004, pp. 441-448.

[2] Weissbach, R.; Teodorescu, R.; Sonnenmeier, J.: Comparison of Time-Based Probability Methods for Estimating Energy Storage Requirements for an Off-Grid Residence, IEEE Energy2030, Atlanta, November 2008.

[3] Lee, D. J.; Wang, L.: Small-Signal Stability Analysis of an Autonomous Hybrid Renewable Energy Power Generation/Energy Storage System Part I: Time-Domain Simulations, IEEE Transaction on Energy Conversion, vol. 19, no. 2, March 2008, pp. 311-320.

[4] El-Ali, A.; Kouta, J.; Al-Samrout, D.; Moubayed, N.; Outbib, R.: A Note on Wind Turbine Generator Connected to a Lead Acid Battery, International Conference on Electromechanical and Power Systems, SIELMEN’09, Iasi, Romania, October 2009, pp. 341- 344.

[5] Barote, L.; Marinescu, C.: Control of Variable Speed  PMSG Wind Stand-Alone System, Proc. of International Conference OPTIM’06, Brasov, vol. II, May, 2006, pp. 243-248.

Permanent Magnet Synchronous Generator-BasedStandalone Wind Energy Supply System

ABSTRACT:

In this paper, a novel algorithm, based on dc link voltage, is proposed for effective energy management of a standalone permanent magnet synchronous generator (PMSG)-based variable speed wind energy conversion system consisting of battery, fuel cell, and dump load (i.e., electrolyzer). Moreover, by maintaining the dc link voltage at its reference value, the output ac voltage of the inverter can be kept constant irrespective of variations in the wind speed and load.

An effective control technique for the inverter, based on the pulse width modulation (PWM) scheme, has been developed to make the line voltages at the point of common coupling (PCC) balanced when the load is unbalanced. Similarly, a proper control of battery current through dc–dc converter has been carried out to reduce the electrical torque pulsation of the PMSG under an unbalanced load scenario.

Based on extensive simulation results using MATLAB/SIMULINK, it has been established that the performance of the controllers both in transient as well as in steady state is quite satisfactory and it can also maintain maximum power point tracking.

KEYWORDS:

  1. DC-side active filter
  2. Permanent magnet synchronous generator (PMSG)
  3. Unbalanced load compensation
  4. Variable speed wind turbine
  5. Voltage control

 SOFTWARE: MATLAB/SIMULINK

CONCLUSION:

Control strategies to regulate voltage of a standalone variable speed wind turbine with a PMSG, battery, fuel cell, and electrolyzer (acts as dump load) are presented in this paper. By maintaining dc link voltage at its reference value and controlling modulation indices of the PWM inverter, the voltage of inverter output is maintained constant at their rated values. From the simulation results, it is seen that the controller can maintain the load voltage quite well in spite of variations in wind speed and load.

An algorithm is developed to achieve intelligent energy management among the wind generator, battery, fuel cell, and electrolyzer. The effect of unbalanced load on the generator is analyzed and the dc–dc converter control scheme is proposed to reduce its effect on the electrical torque of the generator. The dc–dc converter controller not only helps in maintaining the dc voltage constant but also acts as a dc-side active filter and reduces the oscillations in the generator torque which occur due to unbalanced Load. PWM inverter control is incorporated to make the line voltage at PCC balanced under an unbalanced load scenario.

Inverter control also helps in reducing PCC voltage excursion arising due to slow dynamics of aqua elctrolyzer when power goes to it. The total harmonic distortion (THD) in voltages at PCC is about 5% which depicts the good quality of voltage generated at the customer end. The simulation results demonstrate that the performance of the controllers is satisfactory under steady state as well as dynamic conditions and under balanced as well as unbalanced load conditions.

REFERENCES:

[1] S. Müller, M. Deicke, and W. De DonckerRik, “Doubly fed induction generator system for wind turbines,” IEEE Ind. Appl. Mag., vol. 8, no. 3, pp. 26–33, May/Jun. 2002.

[2] H. Polinder, F. F. A. van der Pijl, G. J. de Vilder, and P. J. Tavner, “Comparison of direct-drive and geared generator concepts for wind turbines,” IEEE Trans. Energy Convers., vol. 21, no. 3, pp. 725–733, Sep. 2006.

[3] T. F. Chan and L. L. Lai, “Permanent-magnet machines for distributed generation: A review,” in Proc. 2007 IEEE Power Engineering Annual  Meeting, pp. 1–6.

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