Renewable energy projects in 2018 hyderabad

 

Voltage Sag and Swell Mitigation Using DSTATCOM in Renewable Energy Based Distributed Generation Systems

Voltage Sag and Swell Mitigation Using DSTATCOM

in Renewable Energy Based Distributed Generation Systems

ABSTRACT:

Renewable distributed generation systems are an alternative solution to provide energy locally near customers. However, the supplying of power without disturbance is the main challenge for utilities, especially for systems that integrate fluctuating renewable sources which can cause voltage sag and swell. In this paper, voltage sag and swell issues are investigated. The first studied scenario is related to the disturbance of the energy source and the second one is due to the installation of a heavy load with a sensitive load at the same supplying bus. A D-STATCOM is connected at the point of common coupling (pCC) to mitigate the voltage sag and sell problems. An energy storage battery has been installed at the DC-side of the compensator that gives the possibility to control the voltage at the PCC and exchange the active and reactive power with the grid. A linear proportional integral (PI) feed-forward controller supervises the compensator. The obtained results show that the D-STATCOM compensator behaves as a good solution to mitigate the voltage sag and swell in distribution grid.

 

KEYWORDS:

  1. Voltage sag, Voltage swell
  2. DSTATCOM
  3. Distributed generation
  4. FACTS
  5. Feed forward control
  6. Power quality.

 

SOFTWARE: MATLAB/SIMULINK

 

BLOCK DIAGRAM:

Fig. 1: Proposed power system

Proposed micro-grid schema

Fig. 2: Proposed micro-grid schema

 

EXPECTED SIMULATION RESULTS:

Grid side voltage of D-STATCOM

Fig. 3: Grid side voltage of D-STATCOM

Voltage at PCC point

Fig. 4: Voltage at PCC point

DG output voltage without D-STATCOM

Fig. 5: DG output voltage without D-STATCOM

PCC voltage with D-STATCOM

Fig. 6: PCC voltage with D-STATCOM

 Voltage at PCC

Fig. 7: Voltage at PCC

 Voltage at PCC point

Fig. 8: Voltage at PCC point

 

CONCLUSION:

Voltage sag and swell issues are important for energy suppliers, because of the awareness of customers toward the lack of power service quality and its consequences. A D-ST ACOM can be connected at the PCC in order to mitigate these issues. An energy storage battery can be installed at DC-side of the compensator to control voltage magnitude at the PCC. The performance of compensator using a feed-forward PI controller was investigated. Based on the obtained results, the compensator behaves as a good solution for the voltage sag and swell mitigation.

 

REFERENCES:

  • Lineweber and S. McNulty, ” The cost of power disturbances to industrial & digital economy companies,” EPRl, Palo Alto, Calif., 2001.
  • K. Rao, T. Ganeshkumar, and P. Puthra, “Mitigation of Voltage Sag and Voltage Swell by Using D-STATCOM and PWM Switched Autotransformer.”
  • Peterson, “Distributed renewable energy generation impacts on microgrid operation and reliability,” EPRl, Palo Alto, CA: 2002. 1004045.
  • Hatziargyriou, H. Asano, R. Iravani, and C. Marnay, “Microgrids,” Power and Energy Magazine, IEEE, vol. 5, pp. 78- 94,2007.
  • Khodaei, “Provisional Microgrids,” Smart Grid, IEEE Transactions on, vol. 6, pp. 1107 1115,2015.

Electric Spring for Voltage and Power Stability and Power Factor Correction

ABSTRACT:

Electric Spring (ES), a new smart grid technology, has earlier been used for providing voltage and power stability in a weakly regulated/stand-alone renewable energy source powered grid. It has been proposed as a demand side management technique to provide voltage and power regulation. In this paper, a new control scheme is presented for the implementation of the electric spring, in conjunction with non-critical building loads like electric heaters, refrigerators and central air conditioning system. This control scheme would be able to provide power factor correction of the system, voltage support, and power balance for the critical loads, such as the building’s security system, in addition to the existing characteristics of electric spring of voltage and power stability. The proposed control scheme is compared with original ES’s control scheme where only reactive-power is injected. The improvised control scheme opens new avenues for the utilization of the electric spring to a greater extent by providing voltage and power stability and enhancing the power quality in the renewable energy powered microgrids.

KEYWORDS:

  1. Demand Side Management
  2. Electric Spring
  3. Power Quality
  4. Single Phase Inverter
  5. Renewable Energy

 SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

 

 Fig. 1. Electric Spring in a circuit

 EXPECTED SIMULATION RESULTS:

Fig. 2. Over-voltage, Conventional ES: RMS Line voltage, ES Voltage, and Non-Critical load voltage (ES turned on at t=0.5 sec)

Fig. 3. Over-voltage, Conventional ES: Power Factor of system (ES turned on at t = 0.5 sec)

Fig. 4. Over-voltage, Conventional ES: Active and Reactive power across critical load, non-critical load, and electric spring (ES turned on at t=0.5 sec)

Fig. 5. Under-voltage, Conventional ES: RMS Line voltage, ES Voltage, and Non-Critical load voltage (ES turned on at t=0.5 sec)

Fig. 6. Under-voltage, Conventional ES: Power Factor of system (ES turned on at t = 0.5 sec)

Fig. 7. Under-voltage, Conventional ES: Active and Reactive power across critical load, non-critical load, and electric spring (ES turned on at t=0.5 sec)

Fig.8. Over-voltage, Improvised ES: RMS Line voltage, ES Voltage, and Non-Critical load voltage (ES turned on at t=0.5 sec)

Fig. 9. Over-voltage, Improvised ES: Power Factor of system (ES turned on at t = 0.5 sec)

Fig. 10. Over-voltage, Improvised ES: Active and Reactive power across critical load, non-critical load, and electric spring (ES turned on at t=0.5 sec)

Fig. 11. Under-voltage, Improvised ES: RMS Line voltage, ES Voltage, and Non-Critical load voltage (ES turned on at t=0.5 sec)

Fig. 12. Under-voltage, Improvised ES: Power Factor of system (ES turned on at t = 0.5 sec)

Fig. 13. Under-voltage, Improvised ES: Active and Reactive power across critical load, non-critical load, and electric spring (ES turned on at t=0.5 sec)

CONCLUSION:

In this paper as well as earlier literatures, the Electric Spring was demonstrated as an ingenious solution to the problem of voltage and power instability associated with renewable energy powered grids. Further in this paper, by the implementation of the proposed improvised control scheme it was demonstrated that the improvised Electric Spring (a) maintained line voltage to reference voltage of 230 Volt, (b) maintained constant power to the critical load, and (c) improved overall power factor of the system compared to the conventional ES. Also, the proposed ‘input-voltage-input-current’ control scheme is compared to the conventional ‘input-voltage’ control. It was shown, through simulation and hardware-in-loop emulation, that using a single device voltage and power regulation and power quality improvement can be achieved. It was also shown that the improvised control scheme has merit over the conventional ES with only reactive power injection. Also, it is proposed that electric spring could be embedded in future home appliances [1]. If many non-critical loads in the buildings are equipped with ES, they could provide a reliable and effective solution to voltage and power stability and insitu power factor correction in a renewable energy powered microgrids. It would be a unique demand side management (DSM) solution which could be implemented without any reliance on information and communication technologies.

REFERENCES:

[1] S. Y. Hui, C. K. Lee, and F. F. Wu, “Electric springs – a new smart grid technology,” IEEE Transactions on Smart Grid, vol. 3, no. 3, pp. 1552–1561, Sept 2012.

[2] S. Hui, C. Lee, and F. WU, “Power control circuit and method for stabilizing a power supply,” 2012. [Online]. Available: http://www.google.com/patents/US20120080420

[3] C. K. Lee, N. R. Chaudhuri, B. Chaudhuri, and S. Y. R. Hui, “Droop control of distributed electric springs for stabilizing future power grid,” IEEE Transactions on Smart Grid, vol. 4, no. 3, pp. 1558–1566, Sept 2013.

[4] C. K. Lee, B. Chaudhuri, and S. Y. Hui, “Hardware and control implementation of electric springs for stabilizing future smart grid with intermittent renewable energy sources,” IEEE Journal of Emerging and Selected Topics in Power Electronics, vol. 1, no. 1, pp. 18–27, March 2013.

[5] C. K. Lee, K. L. Cheng, and W. M. Ng, “Load characterisation of electric spring,” in 2013 IEEE Energy Conversion Congress and Exposition, Sept 2013, pp. 4665–4670.

 

 

Simulation and Control of Solar Wind Hybrid Renewable Power System

ABSTRACT:

The sun and wind based generation are well thoroughly considered to be alternate source of green power generation which can mitigate the power demand issues. This paper introduces a standalone hybrid power generation system consisting of solar and permanent magnet synchronous generator (PMSG) wind power sources and a AC load. A supervisory control unit, designed to execute maximum power point tracking (MPPT), is introduced to maximize the simultaneous energy harvesting from overall power generation under different climatic conditions. Two contingencies are considered and categorized according to the power generation from each energy source, and the load requirement. In PV system Perturb & Observe (P&O) algorithm is used as control logic for the Maximum Power Point Tracking (MPPT) controller and Hill Climb Search (HCS) algorithm is used as MPPT control logic for the Wind power system in order to maximizing the power generated. The Fuzzy logic control scheme of the inverter is intended to keep the load voltage and frequency of the AC supply at constant level regardless of progress in natural conditions and burden. A Simulink model of the proposed Hybrid system with the MPPT controlled Boost converters and Voltage regulated Inverter for stand-alone application is developed in MATLAB.

KEYWORDS:

  1. Renewable energy
  2. Solar
  3. PMSG Wind
  4. Fuzzy controller
  5. P&O

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Figure 1. Block diagram of PV-Wind hybrid system

EXPECTED SIMULATION RESULTS:

Figure 2. PV changing irradiation level

Figure 3. Output voltage for PV changing irradiation level

  Figure 4. Wind speed changing level

Figure 5. Output current wind

Figure 6. Output Voltage wind

Case 1 : PI voltage regulated inverter

Figure 7. Output voltage for inverter

Figure 8. Power generation of the hybrid system under varying wind speed and irradiation

Case 2 : fuzzy logic voltage regulated inverter

Figure 9. Output voltage for inverter

Figure 10. Power generation of the hybrid system under varying wind speed and irradiation

 CONCLUSION:

Nature has provided ample opportunities to mankind to make best use of its resources and still maintain its beauty. In this context, the proposed hybrid PV-wind system provides an elegant integration of the wind turbine and solar PV to extract optimum energy from the two sources. It yields a compact converter system, while incurring reduced cost.

The proposed scheme of wind–solar hybrid system considerably improves the performance of the WECS in terms of enhanced generation capability. The solar PV augmentation of appropriate capacity with minimum battery storage facility provides solution for power generation issues during low wind speed situations.

FLC voltage regulated inverter is more power efficiency and reliable compared to the PI voltage regulated inverter, in this context FLC improve the effect of the MPPT algorithm in the power generation system of which sources solar and wind power generation systems.

REFERENCES:

[1] Natsheh, E.M.; Albarbar, A.; Yazdani, J., “Modeling and control for smart grid integration of solar/wind energy conversion system,” 2nd IEEE PES International Conference and Exhibition on Innovative Smart Grid Technologies (ISGT Europe),pp.1-8, 5-7 Dec. 2011.

[2] Bagen; Billinton, R., “Evaluation of Different Operating Strategies in Small Stand-Alone Power Systems,” IEEE Transactions on Energy Conversion, vol.20, no.3, pp. 654-660, Sept. 2005

[3] S. M. Shaahid and M. A. Elhadidy, “Opportunities for utilization of stand-alone hybrid (photovoltaic + diesel + battery) power systems in hot climates,” Renewable Energy, vol. 28, no. 11, pp. 1741–1753, 2003.

[4] Goel, P.K.; Singh, B.; Murthy, S.S.; Kishore, N., “Autonomous hybrid system using PMSGs for hydro and wind power generation,” 35th Annual Conference of IEEE Industrial Electronics, 2009. IECON ’09, pp.255,260, 3-5 Nov. 2009.

[5] Foster, R., M. Ghassemi, and A. Cota, Solar energy: renewable energy and the environment. 2010, Boca Raton: CRC Press.