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.

A Combination of Shunt Hybrid Power Filter and Thyristor-Controlled Reactor for Power Quality

 

ABSTRACT:

This paper proposes a combined system of a thyristor-controlled reactor (TCR) and a shunt hybrid power filter (SHPF) for harmonic and reactive power compensation. The SHPF is the combination of a small-rating active power filter (APF) and a fifth-harmonic-tuned LC passive filter. The tuned passive filter and the TCR form a shunt passive filter (SPF) to compensate reactive power. The small-rating APF is used to improve the filtering characteristics of SPF and to suppress the possibility of resonance between the SPF and line inductances. A proportional–integral controller was used, and a triggering alpha was extracted using a lookup table to control the TCR. A nonlinear control of APF was developed for current tracking and voltage regulation. The latter is based on a decoupled control strategy, which considers that the controlled system may be divided into an inner fast loop and an outer slow one. Thus, an exact linearization control was applied to the inner loop, and a nonlinear feedback control law was used for the outer voltage loop. Integral compensators were added in both current and voltage loops in order to eliminate the steady-state errors due to system parameter uncertainty. The simulation and experimental results are found to be quite satisfactory to mitigate harmonic distortions and reactive power compensation.

KEYWORDS:

  1. Harmonic suppression,
  2. Hybrid power filter
  3. Modeling
  4. Nonlinear control
  5. Reactive power compensation
  6. Shunt hybrid power filter and thyristor-controlled reactor (SHPF-TCRcompensator)
  7. Thyristor-controlled reactor (TCR)

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Basic circuit of the proposed SHPF-TCR compensator.

EXPECTED SIMULATION RESULTS:

 

Fig. 2. Steady-state response of the SHPF-TCR compensator with harmonic generated load.

Fig. 3. Harmonic spectrum of source current in phase 1. (a) Before compensation.

(b) After compensation.

Fig. 4. Dynamic response of SHPF-TCR compensator under varying distorted

harmonic type of load conditions.

 

Fig. 5. Dynamic response of SHPF-TCR compensator under the harmonic and reactive power type of loads.

  Fig. 6. Harmonic spectrum of source current in phase 1. (a) Before compensation. (b) After compensation.

Fig. 7. Steady-state response of the SHPF-TCR compensator with harmonic produced load.

 CONCLUSION:

In this paper, a SHPF-TCR compensator of a TCR and a SHPF has been proposed to achieve harmonic elimination and reactive power compensation. A proposed nonlinear control scheme of a SHPF-TCR compensator has been established, simulated, and implemented by using the DS1104 digital realtime controller board of dSPACE. The shunt active filter and SPF have a complementary function to improve the performance of filtering and to reduce the power rating requirements of an active filter. It has been found that the SHPF-TCR compensator can effectively eliminate current harmonic and reactive power compensation during steady and transient operating conditions for a variety of loads. It has been shown that the system has a fast dynamic response, has good performance in both steady-state and transient operations, and is able to reduce the THD of supply currents well below the limit of 5% of the IEEE-519 standard.

REFERENCES:

[1] A. Hamadi, S. Rahmani, and K. Al-Haddad, “A hybrid passive filter configuration for VAR control and harmonic compensation,” IEEE Trans. Ind. Electron., vol. 57, no. 7, pp. 2419–2434, Jul. 2010.

[2] P. Flores, J. Dixon, M. Ortuzar, R. Carmi, P. Barriuso, and L. Moran, “Static Var compensator and active power filter with power injection capability, using 27-level inverters and photovoltaic cells,” IEEE Trans. Ind. Electron., vol. 56, no. 1, pp. 130–138, Jan. 2009.

[3] H. Hu, W. Shi, Y. Lu, and Y. Xing, “Design considerations for DSPcontrolled 400 Hz shunt active power filter in an aircraft power system,” IEEE Trans. Ind. Electron., vol. 59, no. 9, pp. 3624–3634, Sep. 2012.

[4] X. Du, L. Zhou, H. Lu, and H.-M. Tai, “DC link active power filter for three-phase diode rectifier,” IEEE Trans. Ind. Electron., vol. 59, no. 3, pp. 1430–1442, Mar. 2012.

[5] M. Angulo, D. A. Ruiz-Caballero, J. Lago, M. L. Heldwein, and S. A. Mussa, “Active power filter control strategy with implicit closedloop current control and resonant controller,” IEEE Trans. Ind. Electron., vol. 60, no. 7, pp. 2721–2730, Jul. 2013.

 

Offshore Wind Farms – VSC-based HVDC Connection

 

ABSTRACT:

Due to significantly higher and more constant wind speeds and the shortage of suitable sites for wind turbines on the land, offshore wind farms are becoming very attractive. The connection of the large offshore wind farms is possible with HVAC, classical HVDC and Voltage Source Converter (VSC based) HVDC technology. In this paper their main features will be given. From the economical and technical viewpoint, the type of connection depends on the size of the wind farm and on the distance to the connection point of the system.

As very promising technology, especially from the technical viewpoint, the focus of this paper will be put on the VSC-based HVDC technology. Its main technical features as well as its model will be detailed. At the end, obtained simulation results for different faults and disturbances for one offshore wind farm connected with VSC-based HVDC technology will be presented.

KEYWORDS:

  1. HVDC
  2. IGBT
  3. Offshore wind farm connection
  4. PWM
  5. Requirements
  6. Stability
  7. VSC

SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

 

Fig. 1. Principal scheme of VCS-based HVDC connection

EXPECTED SIMULATION RESULTS:

 

 Fig. 2. Active and reactive power at the connection point during reactive power control

Fig. 3. Active and reactive power at the wind farm side during reactive power control

Fig. 4. Active power, reactive power and voltage at system and wind farm side in case of single phase short circuit near to the connection point – 100ms

Fig. 5. Active power, reactive power and voltage at system and wind farm side in case of single phase short circuit at the wind farm side – 100ms

 CONCLUSION:

The connection of an offshore wind farm depends primarily on the amount of power that has to be transmitted and the distance to the connection point.

Primarily due to comparatively small size and short distance to the connection point as well as due to its lower costs and experience, all actual offshore wind farms and those planned to be installed are still using/plan to use HVAC connection.

The advantages of using a HVDC solution are more significant with increase of the distance and power.

The VSC-based HVDC technology is due to its technical advantages like: active and, especially, reactive power control (voltage control), isolated operation, no need for an active commutation voltage etc. very good solution for an offshore wind farm connection. Performed simulation and their results of simulated faults and disturbances show that the technical requirements can be fulfilled.

REFERENCES:

[1] European Wind Energy Association. (2004). Wind Energy – The Facts. [Online]. Available: http://www.ewea.org

[2] Global Wind Energy Council. (2004). [Online]. Available: http://www.gwec.net

[3] F.W. Koch, I. Erlich, F. Shewarega, and U. Bachmann, “Dynamic interaction of large offshore wind farms with the electric power system”, in Proc. 2003 IEEE Power Tech Conf., Bologna, Italy, vol. 3, pp. 632-638.

[4] J.G. Slootweg and W.L. Kling, “Is the Answer Blowing in the Wind?”, IEEE Power and Energy Magazine, vol. 1, pp. 26-33, Nov./Dec. 2003.

[5] Wind Energy Study 2004. [Online]. Available: http://www.ewea.org

Offshore Wind Farm Power Control Using HVdc Link Control de puissance d’un parc éolien en mer utilisant la liaison CCHT

ABSTRACT:

In this paper, a method is presented to control offshore wind farm output power. This method is able to fix the wind farm output power even during wind speed variations. In the proposed method, the offshore wind farm is connected to the onshore grid through the high-voltage dc (HVdc) cable. Moreover, the power control of the wind turbines is achieved by controlling the HVdc convertors. In the proposed system, the generator side convertors have to control the active power absorbed from the wind, and the grid side ones are obtained to control the HVdc link voltage. The control system is based on applying the appropriate modulation index to the voltage source converters. Two control strategies are proposed and analyzed to control wind farm output power. The simulation results illustrate that the proposed method is able to smooth the output power of the offshore wind farms appropriately. The proposed wind farm configuration and the control system are validated by simulations in the MATLAB/Simulink environment.

KEYWORDS:

  1. Current source inverter (CSI)
  2. Offshore wind farm
  3. Permanent magnet synchronous generator (PMSG)
  4. PQ-bus
  5. Voltage source converter (VSC)

 SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Fig. 1. Proposed configuration of wind turbines connection.

 EXPECTED SIMULATION RESULTS:

 

 Fig. 2. (a) Wind speed variations (m/s). (b) Turbine rotational speed (rad/s).

(c) Turbine efficiency.

Fig. 3. HVdc link voltage.

Fig. 4. Wind farm output power.

CONCLUSION:

In this paper, the configuration and control methods have been proposed for the offshore wind turbines, connected to the onshore grid. This method is capable to control and smooth the wind farm output power, injected to the onshore grid. The proposed system can mitigate the fluctuations of wind farm output power, even during wind speed variations. In other words, the wind farm can operate such as a PQ-bus. Moreover, two strategies (fixed power and MPPT) have been analyzed and compared with each other. Finally, the proposed method is compared with other similar works to smooth the output power of the wind farm. The main result is that the proposed method can smooth the output power better than the TSR, PAC, and OTC methods. But it is a bit weaker than the KEC method in power smoothing issue. Moreover, using this method, the wind farm is able to cooperate in frequency control of the onshore grid by controlling the desired active power, to improve the power system operation, which is the future work of the authors.

REFERENCES:

[1] J. O. Dabiri, “Potential order-of-magnitude enhancement of wind farm power density via counter-rotating vertical-axis wind turbine arrays,” J. Renew. Sustain. Energy, vol. 3, no. 4, p. 043104, 2011.

[2] J. Hua, “A floating platform of concrete for offshore wind turbine,” J. Renew. Sustain. Energy, vol. 3, no. 6, p. 063103, 2011.

[3] A. Urtasun, P. Sanchis, I. S. Martín, J. López, and L. Marroyo, “Modeling of small wind turbines based on PMSG with diode bridge for sensorless maximum power tracking,” Renew. Energy, vol. 55, pp. 138–149, Jul. 2012.

[4] (2007). Global Wind and Energy Council, Market Forecast 2010- 2014. [Online]. Available: http://www.gwec.net/fileadmin/documents/ Publications/GlobalWind2007report/market/forecast%2020102014

[5] M. Kesraoui, N. Korichi, and A. Belkadi, “Maximum power point tracker of wind energy conversion system,” Renew. Energy, vol. 4, no. 10, pp. 2655–2662, 2011.

Modeling and Control of Multi-Terminal HVDC with Offshore Wind Farm Integration and DC Chopper Based Protection Strategies

 

ABSTRACT:

Multi-Terminal HVDC based on three-level neutral-clamped voltage source converters (VSC) is an ideal approach for the integration of DFIG wind farms to the power grid. However, dc-link faults and ac faults are major concerns for the safety and consistency of VSC-HVDC system. This paper demonstrates methods employing both full bridge and half bridge DC-DC converters for the fast clearance and protection of dc and ac ground faults respectively. In addition, control strategies incorporating decoupling control and feed-forward compensation on both grid side and wind farm side VSCs are also presented. Normal operations are observed to examine the performance of the MT-HVDC system, and also dc-link fault and three-phase ground fault at inverter side are simulated to verify the effectiveness of the approach employing DC-DC converters to suppress dc current overshoot in case of dc-link fault and mitigate dc voltage overshoot during three-phase ac ground fault. This proposed MT-HVDC transmission system and the fault-ride through capabilities provided by the dc choppers is validated by the simulation studies using detailed Matlab/Simulink model for normal operation, dc and ac ground faults.

KEYWORDS:

  1. VSC-HVDC
  2. DFIG
  3. DC chopper
  4. Faults

 SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Fig. 1 Topology of the proposed multi-terminal VSC-HVDC system.

EXPECTED SIMULATION RESULTS:

 

Fig. 2 Simulation results of MT-HVDC during normal operation: (a) active power of wind farm, (b) dc voltage, and (c) ac rms current.

Fig. 3 Simulation results of 6 DFIG units during normal operation: (a) active power, (b) reactive power, (c) ac rms voltage, and (d) back-to-back dc-link voltage of DFIG unit.

Fig. 4 Simulation results of MT-HVDC during dc pole-to-pole fault with and without full bridge dc chopper protection: (a) dc voltage, and (b) dc current.

Fig. 5 Simulation results of MT-HVDC during three-phase ac ground fault at inverter side with and without half bridge dc chopper protection: (a) ac rms voltage at inverter side, (b) dc voltage overshoot without protection measures, and (c) dc voltage with protection measures.

CONCLUSION:

This paper investigates a multi-terminal VSC-HVDC system, which integrates two DFIG wind farms to the ac grid. The control strategies of both WFVSC and GSVSC stations are discussed in detail, and two approaches employing both full bridge and half bridge dc choppers are extended and displayed. Simulation studies are carried out in normal, dc pole-to-pole and ac ground fault operations, and the result verifies the effectiveness of the proposed MT-HVDC system in both the performance of wind power delivery and the protection measures for various fault conditions. Specifically, the dc voltage drop and dc current overshoot are eliminated during dc fault with full bridge dc choppers, while only a 8% voltage overshoot is observed with the implementation of half bridge dc choppers in case of three-phase ac ground fault.

REFERENCES:

[1] S. G. Hernandez, E. M. Goytia and O. A. Lara, “Analysis of wide area integration of dispersed wind farms using multiple VSC-HVDC links,” in Proc. of EPE, Sevilla, pp. 17-26, 2008.

[2] S. Towito, M. Berman, G. Yehuda and R. Rabinvici, “Distribution generation case study: electric wind farm doubly fed induction generators”, in Proc. Convention of Electrical and Electronics Engineering(CEEE), Israel, pp. 393-397, Nov. 2006.

[3] N. Flourentzou, V. G. Agelidis, and G. D. Demetriades, “VSC-based HVDC power transmission systems: an overview,” IEEE Trans. Power Electron., vol. 24, no. 3, pp. 592-602, Mar. 2009.

[4] L. Xu, L. Yao, and C. Sasse, “Grid integration of large DFIG-based wind farms ssing VSC transmission,” IEEE Trans. Power Syst., vol. 22, no. 3, pp.976-984, Aug. 2007.

[5] L. Weimers, “HVDC Light: A new technology for a better environment”, IEEE Power Eng. Review, vol. 18, no. 8, pp.19-20, Aug. 1998.

Inertial Response of an Offshore Wind Power Plant with HVDC-VSC

 

ABSTRACT:

This paper analyzes the inertial response of an offshore wind power plant (WPP) to provide ancillary services to the power system grid. The WPP is connected to a high-voltage direct-current voltage source converter HVDC-VSC to deliver the power to the onshore substation. The wind turbine generator (WTG) used is a doubly-fed induction generator (Type 3 WTG). In this paper we analyze a control method for the WTGs in an offshore WPP to support the grid and contribute ancillary services to the power system network. Detailed time domain simulations will be conducted to show the transient behavior of the inertial response of an offshore WPP.

 KEYWORDS:

  1. HVDC
  2. Inertial response
  3. Offshore wind turbine

 SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Fig. 1. Test system schematic

EXPECTED SIMULATION RESULTS:

 

Fig. 2. ΔT order applied to the controller of the DFIG

Fig. 3. DFIG rotating speed, 150 MW

Fig. 4. DFIG electromagnetic torque, 150 MW

Fig. 5. HVDC link voltage , 150 MW

Fig. 6. HVDC link current, 150 MW

Fig. 7. Real and reactive power (rectifier side), 150 MW

Fig. 8. Real and reactive power (inverter side), 150 MW

Fig. 9. DFIG rotating speed, 180 MW

Fig. 10. DFIG electromagnetic torque, 180 MW

Fig. 11. HVDC link voltage , 180 MW

 

Fig. 12. HVDC link current, 180 MW

Fig. 13. Real and reactive power (rectifier side), 180 MW

Fig. 14. Real and reactive power (inverter side), 180 MW

Fig. 15. DFIG rotating speed, 200 MW, 12 m/s

Fig. 16. DFIG electromagnetic torque, 200 MW, 12 m/s

Fig. 17. HVDC link voltage , 200 MW, 12 m/s

Fig. 18. HVDC link current, 200 MW, 12 m/s

 CONCLUSION:

Detailed time domain simulations were conducted in order to analyze the transients present on the inertial response of an offshore WPP delivering power through an HVDC-VSC link. Several results from transient behavior are presented, these results show that an offshore WPP connected to the grid via an HVDC-VSC link is able to deliver inertial response if it is requested.

These results are important as the WPP importance for the power system is growing and its performance during contingencies must be asured.

REFERENCES:

[1] A. Bodin, “HVDC Light—A Preferable Power Transmission System for Renewable Energies.” Proceedings of the 2011 Third International Youth Conference on Energetics; July 7–9, 2011, Leiria, Portugal

[2] M. de Prada Gil, O. Gomis-Bellmunt, A. Sumper, and J. Bergas-Jané, “Analysis of a Multi-Turbine Offshore Wind Farm Connected to a Single Large Power Converter Operated with Variable Frequency.” Energy (36: 5), May 2011; pp. 3272–3281

[3] Feltes, C., and Erlich, I. “Variable Frequency Operation of DFIG-Based Wind Farms Connected to the Grid Through VSC-HVDC Link.” IEEE Power Engineering Society General Meeting, June 24–28, 2007, Tampa, Florida.

[4] N. Miller, K. Clark, M. Cardinal, and R. Delmerico, “Grid-friendly wind plants controls: GE Wind CONTROL—Functionality and field tests,” presented at European Wind Energy Conf., Brussels, Belgium, 2008.

[5] N. W. Miller, K. Clark, and M. Shao, “Impact of frequency responsive wind plant controls on grid performance,” presented at 9th International Workshop on Large-Scale Integration of Wind Power, Quebec, Canada, Oct. 18–19, 2010.

Harmonics Reduction And Power Quality Improvement By Using DPFC

 

ABSTRACT:

The DPFC is derived from the unified power-flow controller (UPFC). The DPFC can be considered as a UPFC with an eliminated common dc link. The active power exchange between the shunt and series converters which is through the common dc link in the UPFC is now through the transmission lines at the third-harmonic frequency. The DPFC employs the distributed concept, in which the common dc-link between the shunt and series converters are eliminated and three-phase series converter is divided to several single-phase series distributed converters through the line. According to the growth of electricity demand and the increased number of non-linear loads in power grids harmonics, voltage sag and swell are the major power quality problems. DPFC is used to mitigate the voltage deviation and improve power quality. Simulations are carried out in MATLAB/Simulink environment. The presented simulation results validate the DPFC ability to improve the power quality.

KEYWORDS:

  1. Load flow control
  2. FACTS
  3. Power Quality
  4. Harmonics
  5. Sag and Swell Mitigation
  6. Distributed Power Flow Controller
  7. Y–Δ transformer

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. DPFC configuration

EXPECTED SIMULATION RESULTS:

 

Fig 2. three phase voltage sag waveform without DPFC

 

Fig. 3 three phase voltage sag waveform with DPFC

 Fig.4 3-ϕ load current swell waveform without DPFC

Fig.5 Mitigation of 3-ϕ load current swell with DPFC

             

Fig.6 Total harmonic distortion of load voltage without DPFC

.Fig.7 Total harmonic distortion of load voltage with DPFC

 CONCLUSION:

This paper has presented a new concept called DPFC. The DPFC emerges from the UPFC and inherits the control capability of the UPFC, which is the simultaneous adjustment of the line impedance, the transmission angle, and the bus voltage magnitude. The common dc link between the shunt and series converters, which is used for exchanging active power in the UPFC, is eliminated. This power is now transmitted through the transmission line at the third-harmonic frequency. The series converter of the DPFC employs the DFACTS concept, which uses multiple small single-phase converters instead of one large-size converter. The reliability of the DPFC is greatly increased because of the redundancy of the series converters. The total cost of the DPFC is also much lower than the UPFC, because no high-voltage isolation is required at the series-converter part and the rating of the components of is low. To improve power quality in the power transmission system, the harmonics due to nonlinear loads, voltage sag and swell are mitigated. To simulate the dynamic performance, a three-phase fault is considered near the load. It is shown that the DPFC gives an acceptable performance in power quality improvement and power flow control.

 REFERENCES:

[1] S.Masoud Barakati Arash Khoshkbar sadigh and Mokhtarpour.Voltage Sag and Swell Compensation with DVR Based on Asymmetrical Cascade Multicell Converter North American Power Symposium (NAPS),pp.1-7,2011.

[2] Zhihui Yuan, Sjoerd W.H de Haan, Braham Frreira and Dalibor Cevoric “A FACTS Device: Distributed Power Flow Controller (DPFC)” IEEE Transaction on Power Electronics, vol.25, no.10, October 2010.

[3] Zhihui Yuan, Sjoerd W.H de Haan and Braham Frreira “DPFC control during shunt converter failure” IEEE Transaction on Power Electronics 2009.

[4] M. D. Deepak, E. B. William, S. S. Robert, K. Bill, W. G. Randal, T. B. Dale, R. I. Michael, and S. G. Ian, “A distributed static series compensator system for realizing active power flow control on existing power lines,” IEEE Trans. Power Del., vol. 22, no. 1, pp. 642–649, Jan. 2007.

[5] D. Divan and H. Johal, “Distributed facts—A new concept for realizing grid power flow control,” in Proc. IEEE 36th Power Electron. Spec. Conf. (PESC), 2005, pp. 8–14.

Designing of Multilevel DPFC to Improve Power Quality

 

ABSTRACT:

According to growth of electricity demand and the increased number of non-linear loads in power grids, providing a high quality electrical power should be considered. In this paper, Enhancement of power quality by using fuzzy based multilevel power flow controller (DPFC) is proposed. The DPFC is a new FACTS device, which its structure is similar to unified power flow controller (UPFC). In spite of UPFC, in DPFC the common dc-link between the shunt and series converters is eliminated and three-phase series converter is divided to several single-phase series distributed converters through the line. This eventually enables the DPFC to fully control all power system parameters. It, also, increases the reliability of the device and reduces its cost simultaneously. In recent years multi level inverters are used high power and high voltage applications .Multilevel inverter output voltage produce a staircase output waveform, this waveform look like a sinusoidal waveform leads to reduction in Harmonics. Fuzzy Logic is used for optimal designing of controller parameters. Application of Fuzzy Multilevel DPFC for reduction of Total Harmonic Distortion was presented. The simulation results show the improvement of power quality using DPFC with Fuzzy logic controller.

KEYWORDS:

  1. FACTS
  2. Power Quality
  3. Multi Level Inverters
  4. Fuzzy Logic
  5. Distributed Power Flow Controller component

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig.1: The DPFC Structure.

EXPECTED SIMULATION RESULTS:

 

 Fig.2: 5 Level Voltage Waveform

Fig.3: Three Phase output Voltage and Current Waveform

Fig.4: Supply Voltage and Current Waveform with unity PF

Fig.5: THD without fuzzy

Fig.6: THD with fuzzy

CONCLUSION:

In this paper Fuzzy Logic Controller technique based distributed power flow controller (DPFC) with multilevel voltage source converter (VSC) is proposed. The presented DPFC control system can regulate active and reactive power flow of the transmission line. We are reducing the THD value from 24.84% to 0.41% by using this technic as shown in fig’s (12) & (13).The series converter of the DPFC employs the DFACTS concept, which uses multiple converters instead of one large-size converter. The reliability of the DPFC is greatly increased because of the redundancy of the series converters. The total cost of the DPFC is also much lower than the UPFC, because no high-voltage isolation is required at the series converter part and the rating of the components are low. Also results show the valid improvement in Power Quality using Fuzzy Logic based Multilevel DPFC.

 REFERENCES:

[1] K Chandrasekaran, P A Vengkatachalam, Mohd Noh Karsiti and K S Rama Rao, “Mitigation of Power Quality Disturbances”, Journal of Theoretical and Applied Information Technology, Vol.8, No.2, pp.105- 116, 2009

[2] Priyanka Chhabra, “Study of Different Methods for Enhancing Power Quality Problems”, International Journal of Current Engineering and Technology, Vol.3, No.2, pp.403-410, 2013

[3] Bindeshwar Singh, Indresh Yadav and Dilip Kumar, “Mitigation of Power Quality Problems Using FACTS Controllers in an Integrated Power System Environment: A Comprehensive Survey”, International Journal of Computer Science and Artificial Intelligence, Vol.1, No.1, pp.1-12, 2011

[4] Ganesh Prasad Reddy and K Ramesh Reddy, “Power Quality Improvement Using Neural Network Controller Based Cascaded HBridge Multilevel Inverter Type D-STATCOM”, International Conference on Computer Communication and Informatics, 2012

[5] Lin Xu and Yang Han, “Effective Controller Design for the Cascaded Hbridge Multilevel DSTATCOM for Reactive Compensation in Distribution Utilities”, Elektrotehniski Vestnik, Vol.78, No.4, pp.229- 235, 2011

Simulation of Distributed Power Flow Controller for Voltage Sag Compensation

ABSTRACT:

In this paper, we introduced a new series-shunt type FACTS controller called as distributed power flow controller to improve and maintain the power quality of an electrical power system. This DPFC method is same as the UPFC used to compensate the voltage sag and the current swell these are voltage based power quality problems. As compared to UPFC the common dc link capacitor is removed and three individual single phase converters are used instead of a three phase series converter. Series referral voltages, branch currents are used in this paper for designing control circuit. The evaluated values are obtained by using MATLAB/SIMULINK.

 KEYWORDS:

  1. DPFC
  2. Power Quality
  3. Voltage Sag
  4. Voltage Swell

 SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Figure 1. Schematic diagram for DPFC.

EXPECTED SIMULATION RESULTS:

 

 Figure 2. Output voltage during fault condition.

Figure 3. Output current during fault condition.

Figure 4. Output voltage compensated by DPFC controller.

Figure 5. Compensated output current by DPFC controller.

Figure 6. Active and reactive power.

Figure 7. THD value of system output voltage without DPFC.

Figure 8. THD value of DPFC (pi controller) load voltage.

Figure 9. THD value of fuzzy controller output voltage.

 CONCLUSION:

In this paper we implemented a concept to controlling the power quality issues i.e DPFC. The proposed theory of this device is mathematical formulation and analysis of voltage dips and their mitigations for a three phase source with linear load. In this paper we also proposed a concept of fuzzy logic controller for better controlling action. As compared to all other facts devices the DPFC based Fuzzy has effectively control all power quality problems and with this technique we get the THD as 3.65% and finally the simulation results are shown above.

 REFERENCES:

  1. Jamshidi A, Barakati MS, Ghahderijani MM. Presented a paper on Impact of distributed power flow controller to improve power quality based on synchronous reference frame method. IACSIT International Journal of Engineering and Technology. 2012 Oct; 4(5):581–5.
  2. Jamshidi A, Barakati MS, Ghahderijani MM. Power quality improvement and mitigation case study using distributed power flow controller; 2012 IEEE International Symposium on Industrial Electronics (ISIE); 2012 May 28-31; Hangzhou; IEEE. p. 464-8.
  3. Patne NR, Thakre KL. Presents a topic on Factor affecting characteristics of voltages. Serbian Journal of Electrical Engg during fault in P.S Engineering. 2008 May; 5(1):171–82.
  4. Enslin JR. Power mitigation problems. Proceedings of IEEE International Symposium Industrial Electronics (ISIE ’98); 1998 Jun. 1:8–20.
  5. Chandra A. A review of active filters for power quality improvement. IEEE Trans Ind Electron. 1999 Oct; 46(5):960–71.

Design and Implementation of DPFC for Power Quality Improvement and Harmonic Mitigation

 

ABSTRACT:

According to growth of electricity demand and the increased number of non-linear loads in power grids, providing a high quality electrical power should be considered. In this paper, voltage sag and swell of the power quality issues are studied and distributed power flow controller (DPFC) is used to mitigate the voltage deviation and improve power quality. The DPFC is a new FACTS device, which its structure is similar to unified power flow controller (UPFC). In spite of UPFC, in DPFC the common dc-link between the shunt and series converters is eliminated and three-phase series converter is divided to several single-phase series distributed converters through the line. The case study contains a DPFC sited in a single-machine infinite bus power system including two parallel transmission lines, which simulated in MATLAB/Simulink environment. The presented simulation results validate the DPFC ability to improve the power quality.

KEYWORDS:

  1. FACTS
  2. Power Quality
  3. Sag and Swell Mitigation
  4. Distributed Power Flow Controller

 SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Fig.1. The DPFC Structure

EXPECTED SIMULATION RESULTS:

 

Fig.2. Three-phase load voltage sag waveform.

Fig.3. Mitigation of three-phase load voltage sag with DPFC.

Fig.4. Three-phase load current swell waveform without DPFC

Fig.5. Mitigation of three-phase load current swell with DPFC.

Fig.6. Total harmonic distortion of load voltage without DPFC.

Fig.7. Total harmonic distortion of load voltage with DPFC.

 CONCLUSION:

To improve power quality in the power transmission system, there are some effective methods. In this paper, the voltage sag and swell mitigation, using a new FACTS device called distributed power flow controller (DPFC) is presented. The DPFC structure is similar to unified power flow controller (UPFC) and has a same control capability to balance the line parameters, i.e., line impedance, transmission angle, and bus voltage magnitude. However, the DPFC offers some advantages, in comparison with UPFC, such as high control capability, high reliability, and low cost. The DPFC is modeled and three control loops, i.e., central controller, series control, and shunt control are design. The system under study is a single machine infinite-bus system, with and without DPFC. To simulate the dynamic performance, a three-phase fault is considered near the load. It is shown that the DPFC gives an acceptable performance in power quality mitigation and power flow control.

REFERENCES:

[1] Ahmad Jamshidi, S. Masoud Barakati, and Mohammad Moradi Ghahderijani, “Power Quality Improvement and Mitigation Case Study Using Distributed Power Flow Controller”, IEEE 2012.

[2] S. Masoud Barakati, Arash Khoshkbar Sadigh and Ehsan Mokhtarpour, “Voltage Sag and Swell Compensation with DVR Based on Asymmetrical Cascade Multi-cell Converter”, North American Power Symposium (NAPS), pp.1 – 7, 2011.

[3] Alexander Eigels Emanuel, John A. McNeill “Electric Power Quality”. Annu. Rev. Energy Environ 1997, pp. 263- 303.

[4] I Nita R. Patne, Krishna L. Thakre “Factor Affecting Characteristics of Voltage Sag Due to Fault in the Power System” Serbian Journal of Electrical engineering. vol. 5, no.1, May2008, pp. 171-182.

[5] J. R. Enslin, “Unified approach to power quality mitigation,” in Proc. IEEE Int. Symp. Industrial Electronics (ISIE ‟98), vol. 1, 1998, pp. 8–20.