Energy Management and Control System for Laboratory Scale Microgrid based Wind-PV-Battery

 ABSTRACT:  

 This paper proposes an energy management and control system for laboratory scale microgrid based on hybrid energy resources such as wind, solar and battery. Power converters and control algorithms have been used along with dedicated energy resources for the efficient operation of the microgrid. The control algorithms are developed to provide power compatibility and energy management between different resources in the microgrid. It provides stable operation of the control in all microgrid subsystems under various power generation and load conditions. The proposed microgrid, based on hybrid energy resources, operates in autonomous mode and has an open architecture platform for testing multiple different control configurations. Real-time control system has been used to operate and validate the hybrid resources in the microgrid experimentally. The proposed laboratory scale microgrid can be used as a benchmark for future research in smart grid applications.

KEYWORDS:

1.      Wind energy

2.      Solar energy

3.      Conversion

4.      Storage

5.      Hybrid system

6.      Control

7.      Energy management

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

  

Fig. 1. Components of the laboratory scale experimental microgrid

EXPECTED SIMULATION RESULTS:

Fig. 2. Wind turbine-generator speed

Fig. 3. PV module current

Fig. 4. DC-link voltage

Fig. 5. Battery current

Fig. 6. Power at different locations in the microgrid (variable wind power)

Fig. 7. Battery state of charge

Fig. 8. Load Voltage

Fig. 9. Power at different locations in the microgrid (variable wind power)

Fig. 10. Battery current

Fig. 11. Battery state of charge

Fig. 12. DC-bus voltage

Fig. 13. Load Voltage

CONCLUSION:

A laboratory scale experimental microgrid of distributed renewable energy sources with battery storage and energy management and control system is developed in this paper. The experimental setup is flexible and allows testing difference power electronics interfaces and combinations. The control software is open source in order to implement different control strategies. This tool contributes to the enhancement of education and research the field of renewable energy and distributed energy systems.

REFERENCES:

[1] A. Bari, J. Jiang, W. Saad and A. Jaekel, “Challenges in the Smart Grid Applications: An Overview,” Int. J. of Distributed Sensor Networks, pp.1–12, 2014.

[2] M. B. Shadmand and R. S. Balog, “Multi-objective optimization and design of photovoltaic-wind hybrid system for community smart DC microgrid,” IEEE Trans. Smart Grid, vol. 5, no. 5, pp. 2635–2643, Sep. 2014.

[3] M. J. Hossain, H. R. Pota, M. A. Mahmud and M. Aldeen, “Robust control for power Sharing in microgrids with low-inertia wind and PV generators,” IEEE Trans. Sustain. Energy, vol. 6, no. 3, pp. 1067–1077, Jul. 2015.

[4] Zaheeruddin and M. Manas, “Renewable energy management through microgrid central controller design: an approach to integrate solar, wind and biomass with battery,” Energy Reports, vol. 1, pp.156–163, 2015.

[5] A. Tani, M. B. Camara and B. Dakyo, “Energy management in the decentralized generation systems based on renewable energy—ultracapacitors and battery to compensate the wind/load power fluctuations,” IEEE Trans. Ind. Appl., vol. 51, no. 2, pp. 1817–1827, 2015.

Control Strategy of Photovoltaic Generation Inverter Grid-Connected Operating and Harmonic Elimination Hybrid System

ABSTRACT:  

This paper proposes a three-phase three-wire photovoltaic generation inverter grid-connected operating and harmonic elimination hybrid system. The hybrid system mainly consists of photovoltaic array battery, photovoltaic output filter, three-phase voltage-type inverter, inverter output filter and passive filters. Based on working principle and working characteristics of the proposed hybrid system, the composite control strategy about active power, reactive power  and harmonic suppression is proposed. The composite control strategy mainly consists of a single closed-loop control slip of active power and reactive power, double closed-loop control slip of harmonics. Simulation results show the correctly of this paper’s contents, the hybrid system have an effective to improve power factor, supply active power for loads and suppress harmonics of micro-grid.

KEYWORDS:

1.      Micro grid

2.      Harmonic restraint

3.      Active power control

4.      Reactive power control

5.      Photovoltaic generation

SOFTWARE: MATLAB/SIMULINK

 CIRCUIT DIAGRAM:

     

Figure 1. Structure of novel hybrid system.

 EXPECTED SIMULATION RESULTS:

(a) Current dynamic waveform of load and grid side

(b) Current spectrum waveform of load and grid side

(c) Voltage and current dynamic waveform of grid side

(d) Voltage waveform of the DC capacitor

Figure 2. Simulation results when photovoltaic generation is connected.

(a) Current dynamic waveform of load and grid side

(b) Current spectrum waveform of load and grid side

(c) Voltage and current dynamic waveform of grid side

(d) Voltage waveform of the DC capacitor

Figure 3. Simulation results when photovoltaic generation is not connected.

CONCLUSION:

Aiming at the shortages and problems of active power, reactive power and harmonic control technology in microgrid, a three-phase three-wire photovoltaic generation inverter grid-connected operating and harmonic elimination hybrid system is proposed in this paper. The principle and control strategy of the proposed hybrid system are studied. Through the research of this paper, the following conclusions can be drawn:

(1) The compensation of active, reactive power and the real-time dynamic control of harmonics can be realized through the proposed hybrid system.

(2) Based on the working principle of the proposed hybrid system at different time, the hybrid control method of active power, reactive power and harmonic suppression is proposed. The proposed control strategy is simple and easy to be implied in engineering.

(3) Simulation results show the correctly of this paper’s contents, at the same time, the proposed control method can also be applied to other similar systems in this paper.

REFERENCES:

[1] Ding Ming, Wang Min.Distributed generation technology. Electric Power Automation Equioment, vol. 24, no.7, pp. 31–36, July 2004.

[2] Liang Youwei , Hu Zhijian , Chen Yunping. A survey of distributed generation and it s application in power system. Power System Technology, vol. 27, no.12, pp. 71-75, December 2003.

[3] Wang Chengshan, Xiao Chaoxia, Wang Shouxiang. Synthetical Control and Analysis of Microgrid. Automation of Electric Power Systems, vol. 32, no.7, pp. 98-103, April 2008.

[4] Liu Yang-hua1,Wu Zheng-qiu,Lin Shun-jiang. Research on Unbalanced Three-phase Power Flow Calculation Method in Islanding Micro Grid. Journal of Hunan University(Natural Sciences) , vol. 36, no.7, pp. 36-40, July 2009.

[5] Xie Qing Hua, Simulation Study on Micro-grid Connection/Isolation Operation Containing Multi-Micro-sources. Shanxi Electric Power,vol. 37, no.8, pp. 10-13, August 2009.

Performance Investigation of Shunt Hybrid Active Power Filter With A Synchronous Reference Frame Based Controller

ABSTRACT:  

This paper presents a novel synchronous reference frame based (SRF) control strategy for shunt hybrid active power filter (SHAPF). The control strategy includes a direct current control (DCC) and an indirect current control (ICC) strategy. SHAPF can achieve harmonic compensation and dynamic reactive power compensation with the proposed controller. In this proposed method, as distinct from studies in literature, dynamic reactive power compensation and dc link voltage control is realized with ICC and harmonic current compensation is realized with DCC. Also, the proposed controller provides a variable SHAPF dc link voltage which is adjusted according to the reactive power compensation requirements in order to decrease the switching losses of converter and achieve power savings. The performance of proposed controller is verified with experimental results.

KEYWORDS:

1.      Active Power Filter (APF)

2.      Harmonics

3.      Reactive Power Compensation

4.      Direct Current Control

5.      Indirect Current Control

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

Fig. 1. Power Circuit Diagram of SHAPF

 EXPECTED SIMULATION RESULTS:

(a)

(b)

Fig.2. Reactive Power Trend (a) and Current Harmonic Spec. (b) of Case I

(a)

(b)

Fig.3. Reactive Power Trend (a) and Current Harmonic Spec. (b) of Case II

CONCLUSION:

This paper presents a SRF based controller approach for SHAPF. In proposed control method, DCC strategy is preferred for harmonic compensation control to maintain superior dynamic and steady state performance on the compensation of low order harmonics. ICC strategy is used for the reactive power compensation controller and the dc link voltage controller to simplify the controller and provide a successful performance without being affected by dynamic changes in active and reactive current components. Additionally, the dc link voltage is determined with adaptive to the reactive power demand of load by the proposed control method. By the help of this ability, the switching losses of SHAPF is decreased by keeping only required voltage level on dc link. The proposed control method is applied on the laboratory prototype of SHAPF. The steady state and dynamic performance of controller is verified with the experimental results.

REFERENCES:

[1] H. Fujita and H. Akagi, “A practical approach to harmonic compensation in power systems-series connection of passive and active filters,” IEEE Trans. Ind. Appl., vol. 27, no. 6, pp. 1020–1025, 1991.

[2] H. Akagi, “Active and hybrid filters for power conditioning,” ISIE’2000. Proc. 2000 IEEE Int. Symp. Ind. Electron. (Cat. No.00TH8543), vol. 1, 2000.

[3] H. Fujita, T. Yamasaki, and H. Akagi, “A hybrid active filter for damping of harmonic resonance in industrial power systems,” IEEE Trans. Power Electron., vol. 15, no. 2, pp. 215–222, Mar. 2000.

[4] S. Srianthumrong and H. Akagi, “Medium-voltage transformerless ac/dc power conversion system consisting of a diode rectifier and a shunt hybrid filter,” IEEE Trans. Ind. Appl., vol. 39, no. 3, pp. 874–882, May 2003.

[5] R. Inzunza and H. Akagi, “A 6.6-kV Transformerless Shunt Hybrid Active Filter for Installation on a Power Distribution System,” IEEE Trans. Power Electron., vol. 20, no. 4, pp. 893–900, Jul. 2005.