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

 BLOCK DIAGRAM:

                                          Fig. 1. Stand-alone wind system configuration.

 EXPERIMENTAL RESULTS:

Fig. 2. The PMSG rotor speed variation:

(a) Simulation results; (b) Experimental results.

Fig. 3. The PMSG electromagnetic torque:

(a) Simulation results; (b) Experimental results.

Fig. 4. The DC link rectifier bridge voltage variation:

(a) Simulation results; (b) Experimental results.

Fig. 5. The converter input current variation:

(a) Simulation results; (b) Experimental results.

Fig. 6. The LAB voltage variation:

(a) Simulation results; (b) Experimental results.

Fig. 7. The LAB current variation:

(a) Simulation results; (b) Experimental results.

Fig. 8. The LAB state of charge (SOC) variation:

(a) Simulation results; (b) Experimental results.

Fig. 9. The active power balance of the system:

(a) Simulation results; (b) Experimental results.

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.

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

CIRCUIT DIAGRAM:

Fig. 1.Complete structure of the stand-alone wind-energy conversion system

 EXPERIMENTAL RESULTS:

Fig. 2.Effect of wind-speed variation on the generated voltage and frequency:

a) Wind speed b) generated line voltage c) frequency of the generated voltage

Fig. 3. DC-link voltage

Fig. 4. Load voltage and current during different periods of wind-speed

variation a) Effective value of the load voltage b) Instantaneous three-phase

load-current waveforms

Fig. 5. Effect of load variation on the generated voltage and frequency at

constant wind speed a) generated line voltage b) frequency of the generated

voltage

Fig. 6. Load voltage and current during different periods of load variations a)

Effective value of load voltage during different loads b) Instantaneous threephase

load-current waveforms

Fig. 7. DC Link Voltage during balanced and unbalanced

Fig. 8. Effective value of the load voltage during both balanced and

unbalanced loading condition

Fig. 9. Load current of each phase during both balanced and unbalanced

loading conditions (a) Instantaneous waveforms (b) Effective value

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

Permanent Magnet Synchronous Generator-Based Standalone 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

CIRCUIT DIAGRAM:

Fig. 1. PMSG-based standalone wind turbine with energy storage and dump load.

EXPERIMENTAL RESULTS:

Fig. 2. Response of mechanical torque for change in wind velocity.

Fig. 3. (a) Load current; (b) wind speed.

Fig. 4. DC link voltage.

Fig. 5. RMS output voltage (PCC voltage).

Fig. 6. Instantaneous output voltage at s.

Fig. 7. Instantaneous output line current.

Fig. 8. Powers.

Fig. 9. Powers.

Fig. 10. DC link voltage.

Fig. 11. Powers.

Fig. 12. DC link voltage.

Fig. 13. Response of controllers.

Fig. 14. Three phase currents for unbalanced load.

Fig. 15. Electrical torque of PMSG with and without dc–dc converter controller.

Fig. 16. Instantaneous line voltages at PCC for unbalanced load.

Fig. 17. (a) RMS value of line voltages at PCC after compensation; (b) modulation

indexes.

Fig. 18. Instantaneous line voltages at PCC after compensation.

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.

[4] M. Fatu, L. Tutelea, I. Boldea, and R. Teodorescu, “Novel motion sensorless control of stand alone permanent magnet synchronous generator (PMSG): Harmonics and negative sequence voltage compensation under nonlinear load,” in Proc. 2007 Eur. Conf. Power Electronics and Applications, Aalborg, Denmark, Sep. 2–5, 2007.

[5] M. E. Haque, K. M. Muttaqi, and M. Negnevitsky, “Control of a stand alone variable speed wind turbine with a permanent magnet synchronous generator,” in Proc. IEEE Power and Energy Society General Meeting, Jul. 2008, pp. 20–24.