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).

 

 

   

Fig. 5. PV currents for proposed MPPT technique.

  

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 ACDC 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.