Integration of Super capacitor 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 super capacitors (SC). Super capacitors 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, Super capacitors 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 super capacitors 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. Super capacitors
  4. DC bus
  5. Energy storage
  6. Energy management
  7. Converters control

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Figure 1. Schematic diagram of photovoltaic energy storage.

EXPECTED SIMULATION RESULTS:

Figure 2. Solar irradianee.

Figure 3. Simulation of ip,’ and itoadwith variable solar irradianee.

Figure 4. Simulation of isc and hal with variable solar irradianee.

Figure 5. Simulation of hood and fpv with variable load.

Figure 6. Simulation of isc and hal with variable load.

Figure 7. Simulation of Vdc with variable load.

Figure 8. Simulation of TLoad and [bat with null photovoltaic current.

Figure 9. Simulation of Iscd 1 with null photovoltaic current.

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.

Integration of PV, Battery and Super capacitor 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. Super capacitor

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig.1. Hybrid system model of PV, Battery and Super capacitor

EXPECTED SIMULATION RESULTS:

Fig.2. DC Bus voltages across two terminals using conventional controller

Fig.3. DC Bus voltages across two terminals using proposed controller

Fig.4. Power consumed by the load using conventional controller

Fig.5. Power consumed by the load using proposed controller

Fig.6. Power sharing between different sources using conventional Controller

Fig.7. Power sharing between different sources using proposed controller

Fig.8. SOC of Battery

Fig.9. Battery Voltage

Fig.10. Battery Current

Fig.11. SOC of Super capacitor

Fig.12. Voltage of Super capacitor

Fig.13. Current of Super capacitor

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 super capacitor. 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.

Induction motor drive for PV water pumping with reduced sensors

ABSTRACT:

This study presents the reduced sensors based standalone solar photovoltaic (PV) energised water pumping. The system is configured to reduce both cost and complexity with simultaneous assurance of optimum power utilisation of PV array. The proposed system consists of an induction motor-operated water pump, controlled by modified direct torque control. The PV array is connected to the DC link through a DC–DC boost converter to provide maximum power point tracking (MPPT) control and DC-link voltage is maintained by a three-phase voltage-source inverter. The estimation of motor speed eliminates the use of tacho generator/encoder and makes the system cheaper and robust. Moreover, an attempt is made to reduce the number of current sensors and voltage sensors in the system. The proposed system constitutes only one current sensor and only one voltage sensor used for MPPT as well as for the phase voltage estimation and for the phase currents’ reconstruction. Parameters adaptation makes the system stable and insensitive toward parameters variation. Both simulation and experimental results on the developed prototype in the laboratory validate the suitability of proposed system.

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1 Block diagram

(a) Conventional system, (b) Proposed system, (c) Scheme of the proposed system

EXPECTED SIMULATION RESULTS:

Fig. 2 Performance indices

(a) PV array during starting to steady state at 1000 W/m2, (b) IMD indices at 1000 W/m2

CONCLUSION:

The modelling and simulation of the proposed system has been carried out in MATLAB/Simulink and its suitability is validated experimentally on a developed prototype in the laboratory. The system comprises of one voltage sensor and one current sensor, which are sufficient for the proper operation of the proposed system. The motor-drive system performs satisfactorily during starting at various insolations, steady-state, dynamic conditions represented by changing insolation. The speed estimation has been carried out by flux components in stationary frame of reference. The flux and torque are controlled separately. Therefore, successful observation of the proposed system with satisfactory performance has been achieved without the mechanical sensors. This topology improves the stability of the system. The stability of the system at rated condition toward stator resistance variation is shown by Nyquist stability curve and the stability toward the rotor-time constant perturbation is shown by Popov’s criteria. The DTC of an induction motor with fixed frequency switching technique reduces the torque ripple. The line voltages are estimated from this DC-link voltage. Moreover, the reconstruction of three-phase stator currents has been successfully carried out from DC-link current. Simulation results are well validated by test results. Owing to the virtues of simple structure, control, cost-effectiveness, fairly good efficiency and compactness, it is inferred that the suitability of the system can be judged by deploying it in the field.

REFERENCES:

[1] Masters, G.M.: ‘Renewable and efficient electric power systems’ (IEEE Press, Wiley and Sons, Inc., Hoboken, New Jersey, 2013), pp. 445–452

[2] Foster, R., Ghassemi, M., Cota, M.: ‘Solar energy: renewable energy and the environment’ (CRC Press, Taylor and Francis Group, Inc., Boca Raton, Florida, 2010)

[3] Parvathy, S., Vivek, A.: ‘A photovoltaic water pumping system with high efficiency and high lifetime’. Int. Conf. Advancements in Power and Energy (TAP Energy), Kollam, India, 24–26 June 2015, pp. 489–493

[4] Shafiullah, G.M., Amanullah, M.T., Shawkat Ali, A.B.M., et al.: ‘Smart grids: opportunities, developments and trends’ (Springer, London, UK, 2013)

[5] Sontake, V.C., Kalamkar, V.R.: ‘Solar photovoltaic water pumping system – a comprehensive review’, Renew. Sustain. Energy Rev., 2016, 59, pp. 1038– 1067

Improved MPPT method to increase accuracy and speed in photovoltaic systems under variable atmospheric conditions

ABSTRACT:

The changes in temperature and radiation cause visible fluctuations in the output power produced by the photovoltaic (PV) panels. It is essential to keep the output voltage of the PV panel at the maximum power point (MPP) under varying temperature and radiation conditions. In this study, a maximum power point tracking (MPPT) method has been developed which is based on mainly two parts: the first part is adapting calculation block for the reference voltage point of MPPT and the second one is Fuzzy Logic Controller (FLC) block to adjust the duty cycle of PWM applied switch (MOSFET) of the DC-DC converter. In order to evaluate the robustness of the proposed method, Matlab/Simulink program has been used to compare with the traditional methods which are Perturb & Observe (P&O), Incremental Conductance (Inc. Cond.) and FLC methods under variable atmospheric conditions. When the test results are observed, it is clearly obtained that the proposed MPPT method provides an increase in the tracking capability of MPP and at the same time reduced steady state oscillations. The accuracy of the proposed method is between 99.5% and 99.9%. In addition, the time to capture MPP is 0.021 sec. It is about four times faster than P&O and five times faster than for Inc. Cond. and, furthermore, the proposed method has been compared with the conventional FLC method and it has been observed that the proposed method is faster about 28% and also its efficiency is about 1% better than FLC method.

KEYWORDS:

  1. PV
  2. MPPT methods
  3. FLC based MPPT
  4. DC-DC converter

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Block diagram of the designed system.

EXPECTED SIMULATION RESULTS:

Fig. 2. PV currents for proposed MPPT technique.

Fig. 3. PV voltages for proposed MPPT technique under variable irradiance (fixed temperature).

Fig. 4. PV power for four different MPPT techniques under variable temperature (fixed irradiance).

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Fig. 5. PV currents for proposed MPPT technique.

This image has an empty alt attribute; its file name is image006-1.gif

Fig. 6. PV voltages for proposed MPPT technique under variable temperature (fixed irradiance).

Fig. 7. (a) P-V characteristics curve, (b) Tracking global peak point for proposed MPPT technique.

CONCLUSION:

This study proposes a novel MPPT method and the detailed performance comparison with commonly used methods such as P&O, Incremental conductance and FLC techniques is achieved. Under sudden change in atmospheric operating conditions, the proposed MPPT method performs better performance than other methods to determine MPP. The efficiency of proposed MPPT method is between 99.5% and 99.9%, while P&O is between 91% and 98%, Inc. Cond. Is between 96% and 99% and FLC is between 98.8% and 99.4% for all case studies. The proposed MPPT method has achieved the lowest oscillation rate at the MPP compared to commonly used methods. This brings the method to the forefront in terms of efficiency. The duration of the proposed MPPT technique to reach a steady state has been measured as 0.021 sec. It is about four times faster than P&O and five times faster than for Inc. Cond. and, furthermore, the proposed method has been compared with the conventional FLC method and it has been observed that the proposed method is faster about 28% than FLC method this means the speed of proposed MPPT technique is the best. At the same time, the amount of oscillation is very low compared to conventional methods. The accuracy of the algorithm is high (%99.9 in many study cases) and also the proposed method is easy to implement in the system.

REFERENCES:

[1] Luo HY, Wen HQ, Li XS, Jiang L, Hu YH. Synchronous buck converter based lowcost and high-efficiency sub-module DMPPT PV system under partial shading conditions. Energy Convers Manage 2016;126:473–87.

[2] Babaa SE, Armstrong M, Pickert V. Overview of maximum power point tracking control methods for PV systems. J Power Energy Eng 2014;2:59–72.

[3] Dolara AFR, Leva S. Energy comparison of seven MPPT techniques for PV systems. J Electromagn Anal Appl 2009;3:152–62.

[4] Ngan MS, Tan CW. A study of maximum power point tracking algorithms for standalone photovoltaic systems. Applied Power Electronics Colloquium (IAPEC): IEEE. 2011. p. 22–7.

[5] Liu JZ, Meng HM, Hu Y, Lin ZW, Wang W. A novel MPPT method for enhancing energy conversion efficiency taking power smoothing into account. Energy Convers Manage 2015;101:738–48.

Implementation of Solar Photovoltaic System with Universal Active Filtering Capability

ABSTRACT:

In this work, a novel technique based on second order sequence filter and proportional resonant controller is pro- posed for control of universal active power filter integrated with PV array system (UAPF-PV). Using a second order sequence filter and sampling it at zero crossing of instant of the load voltage, the active component of distorted load current is estimated which is further used to generate reference signal for shunt active filter. The proposed method has good accuracy in extracting fundamental active component of distorted and unbalanced load currents with reduced mathematical computations. Along with power quality improvement, the system also generates clean energy through the PV array system integrated to its DC-bus. The UAPF-PV system integrates benefits of power quality improvement and distributed generation. The system performance is experimentally evaluated on an experimental prototype in the laboratory under a variety of disturbance conditions such as PCC voltage fall/rise, load unbalancing and variation in solar irradiation.

KEYWORDS:

  1. Power quality
  2. Universal active power filter
  3. Adaptive filtering
  4. Photovoltaic system
  5. Maximum power point tracking
  6.  Sequence filter

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. System configuration of UAPF-PV

EXPECTED SIMULATION RESULTS:

(a) Performance under Load Removal

(b) Performance under Load Addition

Fig. 2. Dynamic Performance under load Unbalance Condition

(a) Performance under PCC Voltage Dip Condition

(b) Performance under Swell Condition

Fig. 3. Dynamic Performance under PCC Voltage dip/rise Condition

Fig. 4. UAPF-PV Response under irradiation Change Condition

Fig. 6. Salient Signals in Extraction of Fundamental Positive Sequence Load Current

(a) Salient Signals in Shunt Active Filter Control

(b) Salient Signals in series active filter Control

Fig. 7. Salient Signals in UAPF-PV Control

CONCLUSION:

The performance of a novel control technique for solar PV system with universal active filtering has been evaluated. The fundamental positive sequence component of nonlinear load current is extracted using a second order sequence filter along with a zero cross detection technique. The series active filter is controlled using a proportional resonant controller implemented in domain along with feedforward component. The system performs satisfactorily under disturbances such as PCC voltage dip/rise, changes in solar radiation and load disturbances. Apart from improving power quality, the system also supplies power from PV array into grid. A comparison of the proposed control shows that the system has improved performance as compared to conventional control techniques with slightly lower computational burden. The system integrates distributed generation along with enhancing power quality of distribution system.

REFERENCES:

[1] S. J. Pinto, G. Panda, and R. Peesapati, “An implementation of hybrid control strategy for distributed generation system interface using xilinx system generator,” IEEE Transactions on Industrial Informatics, vol. 13, no. 5, pp. 2735–2745, Oct 2017.

[2] B. Singh, A. Chandra, K. A. Haddad, Power Quality: Problems and Mitigation Techniques. London: Wiley, 2015.

[3] B. Singh, M. Kandpal, and I. Hussain, “Control of grid tied smart pvdstatcom system using an adaptive technique,” IEEE Transactions on Smart Grid, vol. PP, no. 99, pp. 1–1, 2017.

[4] Y. Singh, I. Hussain, S. Mishra, and B. Singh, “Adaptive neuron detection-based control of single-phase spv grid integrated system with active filtering,” IET Power Electronics, vol. 10, no. 6, pp. 657–666, 2016.

[5] C. Jain and B. Singh, “An adjustable dc link voltage-based control of multifunctional grid interfaced solar pv system,” IEEE Journal of Emerging and Selected Topics in Power Electronics, vol. 5, no. 2, pp. 651–660, June 2017.

Grid to Vehicle and Vehicle to Grid Energy Transfer using Single-Phase Bidirectional AC DC Converter and Bidirectional DC – DC converter

ABSTRACT:

In this paper, a configuration of a single-phase bidirectional AC-DC converter and bidirectional DC-DC converter is proposed to transfer electrical power from the grid to an electrical vehicle (EV) and from an EV to the grid while keeping improved power factor of the grid. In first stage, a 230 V 50 Hz AC supply is converted in to 380V dc using a single-phase bidirectional AC-DC converter and in the second stage, a bidirectional buck–boost dc-dc converter is used to charge and discharge the battery of the PHEV (Plug-in Hybrid Electric Vehicle). In discharging mode, it delivers energy back to the grid at 230V, 50 Hz. A battery with the charging power of 1.2 kW at 120V is used in PHEV. The buck-boost DC-DC converter is used in buck mode to charge and in a boost mode to discharge the battery. A proportional-integral (PI) controller is used to control the charging current and voltage. Simulated results validate the effectiveness of proposed algorithm and the feasibility of system.

KEYWORDS:

  1. Plug-in Hybrid Electric Vehicle (PHEV)
  2. Bidirectional AC-DC Converter
  3. DC-DC Converter
  4. Vehicle to grid (V2G)
  5. Electric drive vehicle (EDVs)

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig.1 Proposed configuration for V2G and G2V Energy transfer

EXPECTED SIMULATION RESULTS:

Fig.2 Charging and discharging of PHEV battery (Full profile)

Fig.3 Charging and discharging of PHEV battery (in large view)

Fig.4. Discharging and Charging of PHEV battery demonstrating unity

Power factor operation

CONCLUSION:

The proposed converter has delivered the AC current to/and from the grid at unity power factor and at very low current harmonics which ultimately prolongs the life of the converter and the battery and minimizes the possibility of distorting the grid voltage. It also enables V2G interactions which could be utilized to improve the efficiency of the grid.

REFERENCES:

[1] Young-Joo Lee, Alireza Khaligh, and Ali Emadi, “Advanced Integrated Bidirectional AC/DC and DC/DC Converter for Plug-In Hybrid Electric Vehicles,” IEEE Trans. on Vehicular Tech. vol. 58, no. 8, pp. 3970-3980, Oct, 2009.

[2] Bhim Singh, Brij N. Singh, Ambrish Chandra, Kamal Al-Haddad, Ashish Pandey and Dwarka P. Kothari, “A review of single-phase improved power quality ac–dc converters,” IEEE Trans. Industrial Electronics, vol. 50, no. 5, pp. 962-981, Oct. 2003.

[3] M.C. Kisacikoglu, B. Ozpineci and L.M. Tolbert, “Examination of a PHEV bidirectional charger system for V2G reactive power compensation,” in Proc. of Twenty-Fifth Annual IEEE Applied Power Electronics Conference and Exposition (APEC), 2010, 21-25 Feb.2010, pp.458-465.

[4] M.C. Kisacikoglu, B. Ozpineci and L.M. Tolbert, “Effects of V2G reactive power compensation on the component selection in an EV or PHEV bidirectional charger,” in Proc. of Energy Conversion Congress and Exposition (ECCE), 2010 IEEE, 12-16 Sept. 2010, pp.870-876.

[5] W. Kempton and J. Tomic, “Vehicle-to-grid power fundamentals: Calculating capacity and net revenue,” J. Power Sources, vol. 144, no. 1, pp. 268–279, Jun. 2005.

Grid Interactive Bidirectional Solar PV Array Fed Water Pumping System

ABSTRACT:

This paper proposes a grid interactive bidirectional solar water pumping system using a three phase induction motor drive (IMD). A single phase voltage source converter (VSC) is used to direct the flow of power from grid supply to the pump and back to the grid from SPV array. A boost converter is used for the maximum power point tracking (MPPT) of the SPV array. A smart power sharing control is proposed, with preference given to the power from SPV array over the grid power. Moreover, the grid input power quality is also improved. Various modes of operation of the pump are elaborated and the performance of the system at starting, in steady state and dynamic conditions are simulated. The simulated results show the novelty and the satisfactory performance of the system.

KEYWORDS:

  1. Solar water pump
  2. MPPT
  3. Grid interactive
  4. Smart power sharing

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Configuration for the single phase grid interactive SPV water pumping system

EXPECTED SIMULATION RESULTS:

Fig. 2(a) Starting performance of the proposed system in mode I

Fig. 2(b) Steady state performance of the proposed system in mode I

Fig. 2(c) Performance of the system in mode I under decreasing radiation from 800 W/m2 to 500 W/m2

Fig. 2(d) Performance of the system in mode I under increasing radiation from 500 W/m2 to 800 W/m2

Fig. 3(a) Starting performance of the system in mode II

Fig. 3(b) Steady state performance of the system in mode II

Fig. 4(a) Characteristics of the system in mode III with decrease in Radiation

Fig. 4(b) Characteristics of the system in mode III with increase in Radiation

Fig. 5(a) Characteristics of the system in mode IV with increase in Radiation

Fig. 5 (b) Characteristics of the system in mode III with decrease in radiation

CONCLUSION:

A single phase grid interactive solar water pumping is presented in the paper. Various modes of operation are identified and simulated in MATLAB Simulink environment. The simulated results have demonstrated the satisfactory performance of the system at starting, and in steady and dynamic conditions. The proposed system not only is able to share the power between two sources but it also improves the quality of power drawn. Moreover, the system manages to feed the power from the SPV array as in when required. The system is well suited for the rural and agricultural usage.

REFERENCES:

[1] J. Zhu, “Application of Renewable Energy,” in Optimization of Power System Operation, Wiley-IEEE Press, 2015, p. 664.

[2] Z. Ying, M. Liao, X. Yang, C. Han, J. Li, J. Li, Y. Li, P. Gao, and J. Ye, “High-Performance Black Multicrystalline Silicon Solar Cells by a Highly Simplified Metal-Catalyzed Chemical Etching Method,” IEEE J. Photovolt., vol. PP, no. 99, pp. 1–06, 2016.

[3] M. Steiner, G. Siefer, T. Schmidt, M. Wiesenfarth, F. Dimroth, and A. W. Bett, “43% Sunlight to Electricity Conversion Efficiency Using CPV,” IEEE J. Photovolt., vol. PP, no. 99, pp. 1–5, 2016.

[4] M. Kolhe, J. C. Joshi, and D. P. Kothari, “Performance analysis of a directly coupled photovoltaic water-pumping system,” IEEE Trans. Energy Convers., vol. 19, no. 3, pp. 613–618, Sep. 2004.

[5] S. R. Bhat, A. Pittet, and B. S. Sonde, “Performance Optimization of Induction Motor-Pump System Using Photovoltaic Energy Source,” IEEE Trans. Ind. Appl., vol. IA-23, no. 6, pp. 995–1000, Nov. 1987.

Fuzzy Logic Based MPPT Control for a PV/Wind Hybrid Energy System

ABSTRACT:

In this paper, we present a modeling and simulation of a standalone hybrid energy system which combines two renewable energy sources, solar and wind, with an intelligent MPPT control based on fuzzy logic to extract the maximum energy produced by the two PV and Wind systems. Moreover, other classical MPPT methods were simulated and evaluated to compare with the FLC method in order to deduce the most efficient in terms of rapidity and oscillations around the maximum power point, namely Perturb and Observe (P&O), Incremental Conductance (INC) for the PV system and Hill Climbing Search (HCS) for the Wind generator. The simulation results show that the fuzzy logic technique has a better performance and more efficient compared to other methods due to its fast response, the good energy efficiency of the PV/Wind system and low oscillations during different weather conditions.

KEYWORDS:

  1. Hybrid energy system
  2. MPPT
  3. Fuzzy Logic Control (FLC)
  4. Wind system
  5. Photovoltaic system
  6. PMSG

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Block diagram of fuzzy logic MPPT controller for PV system.

EXPECTED SIMULATION RESULTS:

Fig. 2. PV generator output power for different MPPT techniques.

Fig. 3. PV generator output voltage for different MPPT techniques.

Fig. 4. Mechanical power of wind turbine for different MPPT techniques.

Fig. 5. Power coefficient (Cp) for different MPPT techniques.

CONCLUSION:

In this work, an intelligent control based on fuzzy logic is developed to improve the performance and reliability of a PV/Wind hybrid energy system, also the implementation of the other conventional MPPT algorithms for compared with the FLC technique. For a best performance analysis of MPPT techniques on the system, the simulations are carried out under different operating conditions. Simulation results show that the fuzzy controller has a better performance because it allows with a fast response and high accuracy to achieve and track the maximum power point than the P&O, INC and HCS methods for the PV and Wind generators respectively.

REFERENCES:

[1] A.V. Pavan Kumar, A.M. Parimi and K. Uma Rao, “Implementation of MPPT control using fuzzy logic in solar-wind hybrid power system,” IEEE International Conference on Signal Processing, Informatics, Communication and Energy Systems (SPICES), India, 19-21 February, 2015.

[2] C. Marisarla and K.R. Kumar, “A hybrid wind and solar energy system with battery energy storage for an isolated system,” International Journal of Engineering and Innovative Technology, vol. 3, n°3, pp. 99-104, ISSN 2277-3754, September 2013.

[3] L. Qin and X. Lu, “Matlab/Simulink-based research on maximum power point tracking of photovoltaic generation,” Physics Procedia, 24, pp.10- 18, 2012.

[4] B. Bendib, F. Krim, H. Belmili, M. F. Almi and S. Boulouma, “Advanced fuzzy MPPT controller for a stand-alone PV system,” Energy Procedia, 50, pp.383-392, 2014.

[5] H. Bounechba, A. Bouzid, K. Nabti and H. Benalla, “Comparison of perturb & observe and fuzzy logic in maximum power point tracker for pv systems,” Energy Procedia, 50, pp.677-684, 2014.

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 the number of required gate drives that would shrink the 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 at a fixed switching frequency. Multi-level voltage waveform harmonics has been analyzed comprehensively which affects the harmonic contents of input current and the size of required filters directly. Full 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

BLOCK DIAGRAM:

Fig. 1. Proposed five-level boost PFC rectifier with reduced number of switches

EXPECTED SIMULATION RESULTS:

Fig. 2. Experimental results from steady-state operation of the rectifier

Fig. 3. Experimental results during 50% increase in the load

Fig. 4. Experimental results during AC source voltage variation

Fig. 5. Experimental results during 25% raise in the DC voltage reference

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 real applications. Comprehensive experimental tests including change in the load, AC voltage fluctuation and generating different DC voltage values have been performed to ensure the good dynamic performance of the rectifier, adopted controller and switching technique. Moreover, the low THD of the input current has been measured to validate the advantage of multilevel waveforms in reducing harmonic contents and consequently diminishing the size of required filters at the input of the converters.

REFERENCES:

[1] 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, no. 3, pp. 641-660, 2004.

[2] M. Mobarez, M. Kashani, and S. Bhattacharya, “A Novel Control Approach For Protection of Multi-Terminal VSC Based HVDC Transmission System Against DC Faults,” IEEE Trans. Ind. Applications, vol. PP, no. 99, pp. 1-1, 2016.

[3] H. Mortazavi, H. Mehrjerdi, M. Saad, S. Lefebvre, D. Asber, and L. Lenoir, “A Monitoring Technique for Reversed Power Flow Detection With High PV Penetration Level,” IEEE Trans. Smart Grid, vol. 6, no. 5, pp. 2221-2232, 2015.

[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] H. Vahedi, H. Y. Kanaan, and K. Al-Haddad, “PUC converter review: Topology, control and applications,” in IECON 2015-41st Annual Conference of the IEEE Industrial Electronics Society, Japan, 2015, pp. 4334-4339.

Evaluation of Battery System for Frequency Control in Interconnected Power System with a Large Penetration of Wind Power Generation

ABSTRACT:

Recently, a lot of distributed generations such as wind power generation are going to be installed into power systems. However, the fluctuation of these generator outputs affects the system frequency. Therefore, introduction of battery system to the power system has been considered in order to suppress the fluctuation of the total power output of the distributed generation. For frequency analysis, we use the interconnected 2-area power system model. It is assumed that a small control area with a large penetration of wind power plants is interconnected into a large control area. In this system, the tie line power fluctuation is very large as well as the system frequency fluctuation. It is shown that the installed battery can suppress these fluctuations and that the effect of battery on suppression of fluctuations depends on the battery capacity. Then, the required battery capacity for suppressing the tie line power deviation within a given level is calculated.

KEYWORDS:

  1. Battery
  2. Distributed Generation
  3. Frequency
  4. Load Frequency Control (LFC)
  5. Power System
  6. Tie Line Power
  7. Wind Power Generation

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Battery system model.

EXPECTED SIMULATION RESULTS:

(a) Tie line power flow

(b) system frequency (Area 2)

Fig. 2. Impact of LFC control method.

  • (a) Tie line power flow

(b) System frequency (Area 2)

(c) Battery output

Fig. 3. Behaviors of tie line power flow, system frequency and battery

output with/without battery (Kb = 0.5, Tb = 0.5).

(a) Tie line power flow

(b) Battery stored energy

(c) Battery output

Fig. 4 Behaviors of tie line power and output and stored energy of battery (9OMWh, 1500MW)

CONCLUSION

In this paper, we have analyzed the impact of installed wind power generation and battery on the system frequency and the tie line power. In 2-area power systems, the tie line power fluctuation is remarkably large as well as the system frequency fluctuation. It has been made clear that the installed battery can suppress these fluctuations and that the effect of battery on suppression of these fluctuations depends on battery capacity. If the stored energy of battery reaches the full capacity, the battery output changes to zero suddenly and the large fluctuation is caused. Therefore, the stored energy needs to be controlled within the rated storage capacity. Based on this need, the required battery capacity for suppressing the tie line power deviation within a reference level has been calculated. If battery and LFC generator are controlled cooperatively, installation of battery with a larger capacity makes it possible to decrease LFC capacity of the conventional generators. In the near future, a new method to calculate the optimal battery storage capacity (MWh) and the appropriate power converter capacity (MW) for various kinds of wind power generation patterns and an effective control method of the battery system for reducing the battery capacity and LFC capability of the conventional power plants will be studied.

REFERENCES:

[1] W. El-Khattam and M. M. A. Salama, “Distributed generation technologies, definitions and benefits,” Electric Power Systems Research, vol. 71, issue 2, pp. 1 19-128, Oct. 2004.

[2] N. Jaleeli, L. S. VanSlyck, D. N. Ewart, L. H. Fink, and A. G. Hoffmann, “Understanding automatic generation control,” IEEE Trans. Power Syst., vol. 7, pp. 1106-1122, Aug. 1992.

[3] A. Murakami, A. Yokoyama, and Y. Tada, “Basic study on battery capacity evaluation for load frequency control (LFC) in power system with a large penetration of wind power generation,” T. IEE Japan, vol. 126-B, no. 2, pp. 236-242, Feb. 2006. (in Japanese)

[4] P. Kunder, “Power System Stability and Control, ” McGraw-Hill, 1994.

[5] A. J. Wood and B. F. Wollenberg, “Power Generation Operation and Control,” 2nd ed., Wiley, New York, 1966.