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

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

 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 low cost 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.

Solar Photovoltaic Powered Sailing Boat Using Buck Converter

ABSTRACT

 The main objective of this paper is to establish technical and economical aspects of the application of stand-alone photovoltaic (PV) system in sailing boat using a buck converter in order to enhance the power generation and also to minimize the cost. Performance and control of dc-dc converter, suitable for photovoltaic (PV) applications, is presented here. A buck converter is employed here which extracts complete power from the PV source and feeds into the dc load. The power, which is fed into the load, is sufficient to drive a boat. With the help of matlab simulink software PV module and buck model has been designed and simulated and also compared with theoretical predictions.

KEYWORDS

  1. Buck Converter
  2. Ideal Switch
  3. Matlab Simulink
  4. PV
  5. Solar Sailing Boat

 SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM

Figure 1. Schematic Diagram of PV powered Sailing Boat

 EXPECTED SIMULATION RESULTS

 Figure 2. Simulation result of maximum voltage, current and power in PV array

Figure 3. Simulation result of Buck converter

Figure 4. Simulation result of PV with Buck

 CONCLUSION

Here proposed a solar PV powered sailing boat using buck converter. And tested the effectiveness of the proposed control scheme. This is a new and innovative application which is fully environmental friendly and is almost pollution less. As the upper portion of the boat is unused, solar panels are implemented in that portion quite easily, without requiring extra space. Fuel cost is not required in day time due to the presence of sunlight. lastly, energy pay back period will be lesser than diesel run boat.

 REFERENCES

 [1] P V or  ob i e  v, Y u. V or ob i  e v. Automatic Sun Tracking Solar Electric Systems for Applications on Transport. 7th International Conference on Electrical Engineering, Computing Science and Automatic Control. 2010.

[2] Nob u  y u l  u K  as a, Ta  k  ah i k o Ii d a, Hide o I w a motto. An invert er using buck-boost type chopper circuits for popular small-scale photo voltaic power system. IEEE. 1999.

[3] Pen g Zhang, Wen yuan Li, S her win Li, Yang Wang, Wei dong Xi a o. Reliability assessment of photo voltaic power systems: Review of current status and future perspectives. Applied Energy. 2013; 104(2013): 822–833,

[4] M Nag a o, H Ho r i k a w a, K Ha r a d a. Photo voltaic System using Buck-Boost PW  M Invert er. Trans. of IE E J. 1994; ll 4(D): 885-892.

[5] A Z e g a o u i, M Ail l e r i e, P Pet it, JP S a wick i, JP Charles, AW Be la r bi. Dynamic behavior of P V generator trackers under irradiation and temperature changes. Solar Energy. 2011; 85(2011): 2953–2964.

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

BLOCK DIAGRAM:

Fig. 1. The system configuration of PV/wind hybrid power system.

 EXPECTED SIMULATION RESULTS:

(a) Solar Irradiance.

(b) PV array voltage.

(c) PV array current.

(d) A derivative of power with respect to voltage (dPpv/dVpv).

Fig. 2. Performance of PV array during the variation of solar irradiance.

(a) PV DC-link Voltage.

(b) d-q axis components of injected current from PV station.

(c) Injected active and reactive power from PV station.

(d) Grid voltage and injected current from PV station.

(e) The power factor of the inverter.

(f) Injected current from PV station.

Fig. 3. Performance of PV station during variation of the solar irradiance.

(a) Wind speed profile.

(b) The mechanical torque of wind turbine.

(c) The DC-bus voltage of DFIG.

(d) Injected active and reactive power from the wind farm.

(e) The power factor of the wind farm.

(f) Injected current from the wind farm.

Fig. 4. Performance of wind farm during variation of the wind speed.

(a) Power flow between PV station, wind farm, and hybrid power system.

(b) Injected active and reactive power from the hybrid system.

(c) PCC-bus voltage.

Fig. 5. Performance of hybrid power system at PCC-bus.

 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.

 

A Synchronous Generator Based Diesel-PV Hybrid Micro-grid with Power Quality Controller

 

ABSTRACT:

This paper presents an isolated microgrid, with synchronous generator(SG) based diesel generation (DG) system in combination with solar photo-voltaic(PV). The DG supplies power to the load directly, and a battery supported voltage source converter (VSC) is connected in shunt at point of common coupling (PCC). The PV array is connected at DC-link of the VSC through a boost converter. A high order optimization based adaptive filter control scheme is used for maintaining the quality of PCC voltages and source currents. This controller makes the waveform free of distortion, removes errors due to unbalances, corrects the power factor and makes the source current smooth sinusoidal, irrespective of the nature of load. MATLAB/Simulink based simulation results demonstrate satisfactory performance of the given system.

KEYWORDS:

  1. Battery
  2. Diesel generator
  3. LMF
  4. Power quality
  5. PV

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

 

 

Fig. 1 System model

 EXPECTED SIMULATION RESULTS:

 

 Fig. 2 Steady State Response of DG-PV micro-grid

Fig. 3 Dynamic Response of DG-PV micro-grid

CONCLUSION:

An isolated SG based DG and PV hybrid micro-grid has been presented here, with a battery suppported VSC connected at PCC. Three-phase adaptive control is used for power quality improvement through VSC. The given system and control have been simulated in MATLAB/Simulink environment and results demonstrate their satisfactory performance in both steady state and dynamic conditions.

REFERENCES:

[1] G. Shafiullah et al., “Meeting energy demand and global warming by integrating renewable energy into the grid,” in 22nd Australasian Universities Power Engg. Conf. (AUPEC), pp. 1–7, Bali, 2012.

[2] M. Milligan et al., “Alternatives No More: Wind and Solar Power Are Mainstays of a Clean, Reliable, Affordable Grid,” IEEE Power & Energy Mag., vol. 13, no. 6, pp. 78–87, Nov.-Dec. 2015.

[3] L. Partain and L. Fraas, “Displacing California’s coal and nuclear generation with solar PV and wind by 2022 using vehicle-to-grid energy storage,” IEEE Photovoltaic Specialist Conf., pp. 1–6, LA, 2015.

[4] Daniel E. Olivares et al., “Trends in Microgrid Control,” in 2015 IEEE Trans. Smart Grid, vol. 5, no.4, pp. 1905–1919, July, 2014.

[5] Z. Zavody, “The grid challenges for renewable energy An overview and some priorities,” IET Seminar on Integrating Renewable Energy to the Grid, pp. 1–24, London 2014.

Distributed Generation System Control Strategies in Microgrid Operation

ABSTRACT:

Control strategies of distributed generation (DG) are search for different combination of DG and storage units in a microgrid. This paper  grow a detailed photovoltaic (PV) array model with maximum power point tracking (MPPT) control, and produce real and reactive power (PQ) control and droop control for DG system for microgrid operation. In grid-related mode, PQ control is grown by ruling the active and reactive power output of DGs in agreement with assigned note.

VSC

In islanded mode, DGs are reserved by droop control. Droop control tool power reallocation between DGs based on predefined droop quality at any time load changes or the microgrid is connected/disconnected to the grid, while the microgrid voltage and density is manage at give levels. This paper presents results from a test microgrid system exist of a voltage source converter (VSC) integrate with a DG, a PV array with MPPT, and changeable loads.

ISLANDED

The control plan are tested via two scenarios: the first one is to switch between grid-connected mode and islanded mode and the second one is to change loads in islanded mode. Through voltage, density, and power quality in the simulation under such two scenarios, the planned control plan can be display to work correctly and efficiency.

KEYWORDS:

  1. Distributed generation
  2. PV
  3. Microgrid
  4. Droop control
  5. PQ control

 SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

image001

Fig. 1. Schematic of the microgrid.

CONTROL SYSTEM:

image002

Fig. 2. Schematic of the PQ control.

image003

Fig. 3. Schematic of the droop control.

 EXPECTED SIMULATION RESULTS:

 image004

Fig. 4. PQ control under grid-connected mode.

image005

Fig. 5. Droop control for switching modes.

image006

Fig. 6. Droop control for varying load.

CONCLUSION:

In this paper a exact PV model with MPPT, and PQ and droop controllers is growth for inverter integrate DGs. The use of PQ control protect that DGs can generate certain power in agreement with real and reactive power references. Droop controller is growth to protect the quick dynamic frequency response and proper power sharing between DGs when a forced isolation occurs or load changes.

DG

Compared to pure V/f control and master-slave control, the proposed control method which have the ability to operate without any online signal communication between DGs make the system operation cost-effective and fast respond to load changes. The simulation results get shows that the proposed controller is efficient in performing real and reactive power tracking, voltage control and power sharing during both grid-connected mode and islanded mode.

MICROGRID

To fully represent the complication of the microgrid, future work will include the growth of hierarchical monitor for a microgrid exist of several DGs and energy storage system. The function of primary controller is to commit optimum power reference to each DG to match load balances and the secondary controllers are create to control local voltage and density.

REFERENCES:

Barsali, S., Ceraolo M., Pelacchi, P., and Poli, D. (2002). Control techniques of dispersed generators to improve the continuity of electricity supply. IEEE Conf., Power Engineering Society, vol.2, pp.789-794.

Cai, N., and Mitra J. (2010). A decentralized control architecture for a microgrid with power electronic interfaces. IEEE conf., North American Power Symposium, pp. 1-8.

Chen, X., Wang, Y.H., and Wang, Y.C. (2013). A novel seamless transferring control method for microgrid based on master-slave configuration. IEEE Conf., ECCE Asia, pp. 351-357.

Cho, C. H., Jeon, J.H., Kim, J.Y., Kwon, S., Park, K., and Kim, S. (2011). Active synchronizing control a microgrid. IEEE Trans., Power Electron., vol. 26, no. 12, pp. 3707-3719

Choi, J.W. and Sul, S.K. (1998). Fast current controller in three-phase AC/DC boost converter using d-q axis crosscoupling. IEEE Trans., Power Electron., vol.13, no.1, pp. 179-185.