A STATCOM-Control Scheme for Grid Connected Wind Energy System for Power Quality Improvement


Injection of the wind power into an electric grid affects the power quality. The performance of the wind turbine and thereby power quality are determined on the basis of measurements and the norms followed according to the guideline specified in International Electro-technical Commission standard, IEC-61400. The influence of the wind turbine in the grid system concerning the power quality measurements are-the active power, reactive power, variation of voltage, flicker, harmonics, and electrical behavior of switching operation and these are measured according to national/international guidelines. The paper study demonstrates the power quality problem due to installation of wind turbine with the grid. In this proposed scheme STATic COMpensator (STATCOM) is connected at a point of common coupling with a battery energy storage system (BESS) to mitigate the power quality issues.

The battery energy storage is integrated to sustain the real power source under fluctuating wind power. The STATCOM control scheme for the grid connected wind energy generation system for power quality improvement is simulated using MATLAB/SIMULINK in power system block set. The effectiveness of the proposed scheme relives the main supply source from the reactive power demand of the load and the induction generator. The development of the grid co-ordination rule and the scheme for improvement in power quality norms as per IEC-standard on the grid has been presented.



  1. International electro-technical commission (IEC)
  2. power quality
  3. wind generating system (WGS)






Fig.1.System operational scheme in grid system.




Fig. 1. Three phase injected inverter Current.

Fig. 2. (a) Source Current. (b) Load Current. (c) Inverter Injected Current. (d) Wind generator (Induction generator) current.

Fig. 3. (a) DC link voltage. (b) Current through Capacitor, 
STATCOM output voltage.

Fig. 5. Supply Voltage and Current at PCC.

Fig.6.(a) Source Current. (b) FFT of source current.                

Fig.7.(a) Source Current. (b) FFT of source current



The paper presents the STATCOM-based control scheme for power quality improvement in grid connected wind generating system and with non linear load. The power quality issues and its consequences on the consumer and electric utility are presented. The operation of the control system developed for the STATCOM-BESS in MATLAB/SIMULINK for maintaining the power quality is simulated. It has a capability to cancel out the harmonic parts of the load current. It maintains the source voltage and current in-phase and support the reactive power demand for the wind generator and load at PCC in the grid system, thus it gives an opportunity to enhance the utilization factor of transmission line. The integrated wind generation and STATCOM with BESS have shown the outstanding performance. Thus the proposed scheme in the grid connected system fulfills the power quality norms as per the IEC standard 61400-21.



 Sannino, “Global power systems for sustainable development,” in IEEE General Meeting, Denver, CO, Jun. 2004.

  • S. Hook, Y. Liu, and S. Atcitty, “Mitigation of the wind generation integration related power quality issues by energy storage,” EPQU J., vol. XII, no. 2, 2006.
  • Billinton and Y. Gao, “Energy conversion system models for adequacy assessment of generating systems incorporating wind energy,” IEEE Trans. on E. Conv., vol. 23, no. 1, pp. 163–169, 2008, Multistate.
  • Wind Turbine Generating System—Part 21, International standard-IEC 61400-21,
  • Manel, “Power electronic system for grid integration of renewable energy source: A survey,” IEEE Trans. Ind. Electron., vol. 53, no. 4, pp. 1002–1014, 2006, Carrasco.

Improving the Dynamic Performance of Wind Farms with STATCOM


When integrated to the power system, large wind farms can pose voltage control issues among other problems. A thorough study is needed to identify the potential problems and to develop measures to mitigate them. Although integration of high levels of wind power into an existing transmission system does not require a major redesign, it necessitates additional control and compensating equipment to enable (fast) recovery from severe system disturbances. The use of a Static Synchronous Compensator (STATCOM) near a wind farm is investigated for the purpose of stabilizing the grid voltage after grid-side disturbance such as a three phase short circuit fault. The strategy focuses on a fundamental grid operational requirement to maintain proper voltages at the point of common coupling by regulating the voltage. The DC voltage at individual wind turbine (WT) inverters is also stabilized to facilitate continuous operation of wind turbines  during disturbances.



  1. Wind turbine
  2. Doubly-fed Induction Generator
  4. Three phase fault
  5. Reactive power




wind farm with statcom

Fig. 1. Block diagram of a Doubly-fed induction generator

Fig. 2 Test System


Fig. 3. Voltage at the fault bus (Load bus) , Voltage at the fault bus (Zoomed version)

Fig. 4. Reactive power in the system with no compensating device, Reactive power in the system with mechanically switched capacitors

Fig. 5. Reactive and active power of the 25 MVA STATCOM for Case 3, AC and DC busbar voltages of the STATCOM for Case III.

Fig. 6. Reactive and active powers of only the STATCOM for Case 4, Reactive power and terminal voltage of only the the MSC for Case 4.

Fig. 7. Reactive powers of the system with a STATCOM and MSC

Fig. 8. Reactive power of the 125 MVA STATCOM for Case 5.



Wind turbines have to be able to ride through a fault without disconnecting from the grid. When a wind farm is connected to a weak power grid, it is necessary to provide efficient power control during normal operating conditions and enhanced support during and after faults. This paper explored the possibility of connecting a STATCOM to the wind power system in order to provide efficient control. An appropriately sized STATCOM can provide the necessary reactive power compensation when connected to a weak grid. Also, a higher rating STATCOM can be used for efficient voltage control and improved reliability in grid connected wind farm but economics limit its rating. Simulation studies have shown that the additional voltage/var support provided by an external device such as a STATCOM can significantly improve the wind turbine’s fault recovery by more quickly restoring voltage characteristics. The extent to which a STATCOM can provide support depends on its rating. The higher the rating, the more support provided. The interconnection of wind farms to weak grids also influences the safety of wind turbine generators. Some of the challenges faced by wind turbines connected to weak grids are an increased number and frequency of faults, grid abnormalities, and voltage and frequency fluctuations that can trip relays and cause generator heating.



  • http://www.awea.org/newsroom/releases/Wind_Power_Capacity_012307. html, accessed Nov. 2007.
  • Sun, Z. Chen, F. Blaabjerg, “Voltage recovery of grid-connected wind turbines with DFIG after a short-circuit fault,” 2004 IEEE 35th Annual Power Electronics Specialists Conf., vol. 3, pp. 1991-97, 20-25 June 2004.
  • Muljadi, C.P. Butterfield, “Wind Farm Power System Model Development,” World Renewable Energy Congress VIII, Colorado, Aug- Sept 2004.
  • M. Muyeen, M.A. Mannan, M.H. Ali, R. Takahashi, T. Murata, J. Tamura, “Stabilization of Grid Connected Wind Generator by STATCOM,” IEEE Power Electronics and Drives Systems Conf., Vol. 2, 28-01 Nov. 2005.
  • Saad-Saoud, M.L. Lisboa, J.B. Ekanayake, N. Jenkins, G. Strbac, “Application of STATCOMs to wind farms,” IEE Proceedings – Generation, Transmission, Distribution, vol. 145, pp.1584-89, Sept 1998.

A FACTS Device Distributed Power Flow Controller (DPFC)


This paper presents a new component within the flexible ac-transmission system (FACTS) family, called distributed power-flow controller (DPFC). The DPF Controller 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 FACTS (D-FACTS) concept, which is to use multiple small-size single-phase converters instead of the one large-size three-phase series converter in the UPFC. The large number of series converters provides redundancy, thereby increasing the system reliability. As the D-FACTS converters are single-phase and floating with respect to the ground, there is no high-voltage isolation required between the phases. Accordingly, the cost of the DPFC system is lower than the UPFC. The DPFC has the same control capability as the UPFC, which comprises the adjustment of the line impedance, the transmission angle, and the bus voltage. The principle and analysis of the DPFC are presented in this paper and the corresponding experimental results that are carried out on a scaled prototype are also shown.



  1. AC–DC power conversion
  2. Load flow control
  3. Power electronics
  4. Power semiconductor devices
  5. Power-transmission





facts device

Fig. 1. DPFC control block diagram.



 Fig. 2. DPFC operation in steady state: line current.       


Fig. 3. DPFC operation in steady sta te:series converter voltage.

Fig. 4. DPFC operation in steady state: bus

Fig. 5. Reference voltage for the series converters. voltage and current at the Δ side of the transformer

Fig. 6. Step response of the DPFC: series converter

Fig. 7. Step response of the DPFC: linecurrent. voltage.

Fig. 8. Step response : active and reactive power injected by the series converter at the fundamental frequency.

Fig.9. Step response: bus voltage and current at the Δ of the transformer



 This paper has presented a new concept called Distributed power flow controller. It 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 D-FACTS 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 this controller 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. The DPFC concept has been verified by an experimental setup. It is proved that the shunt and series converters in the DPFC can exchange active power at the third-harmonic frequency, and the series converters are able to inject controllable active and reactive power at the fundamental frequency.



 -H. Song and A. Johns, Flexible ac Transmission Systems (FACTS) (IEE Power and Energy Series), vol. 30. London, U.K.: Institution of Electrical Engineers, 1999.

  • G. Hingorani and L. Gyugyi, Understanding FACTS : Concepts and Technology of Flexible AC Transmission Systems. New York: IEEE Press, 2000.
  • Gyugyi, C.D. Schauder, S. L.Williams, T. R. Rietman,D. R. Torgerson, andA. Edris, “The unified power flowcontroller:Anewapproach to power transmission control,” IEEE Trans. Power Del., vol. 10, no. 2, pp. 1085–1097, Apr. 1995.
  • -A. Edris, “Proposed terms and definitions for flexible ac transmission system (facts),” IEEE Trans. Power Del., vol. 12, no. 4, pp. 1848–1853, Oct. 1997.
  • K. Sen, “Sssc-static synchronous series compensator: Theory, modeling, and application,” IEEE Trans. Power Del., vol. 13, no. 1, pp. 241–246, Jan. 1998.

Matrix Converters: A Technology Review


The matrix converter is an array of controlled semiconductor switches that connects directly the three-phase source to the three-phase load. This converter has several attractive features that have been investigated in the last two decades. In the last few years, an increase in research work has been observed, bringing this topology closer to the industrial application. This paper presents the state-of-the-art view in the development of this converter, starting with a brief historical review. An important part of the paper is dedicated to a discussion of the most important modulation and control strategies developed recently. Special attention is given to present modern methods developed to solve the commutation problem. Some new arrays of power bidirectional switches integrated in a single module are also presented. Finally, this paper includes some practical issues related to the practical application of this technology, like overvoltage protection, use of filters, and ride-through capability.


  1. AC–AC power conversion
  2. Converters
  3. Matrix




 matrix converter

Fig. 1. Simplified circuit of a 3 x 3 matrix converter



Phase output voltage

Fig. 2. Typical waveforms. (a) Phase output voltage. (b) Load current.

maximum voltage ratio

Fig. 3. Illustrating maximum voltage ratio of 50%.

voltage ratio improvement
Fig. 4. Illustrating voltage ratio improvement to 87%.

Line-to-line voltage and current

Fig. 5. Line-to-line voltage and current in the load with the indirect method. Output frequency of 50 Hz.


 After two decades of research effort, several modulation and control methods have been developed for the matrix converter, allowing the generation of sinusoidal input and output currents, operating with unity power factor using standard processors. The most important practical implementation problem in the matrix converter circuit, the commutation problem between two controlled bidirectional switches, has been solved with the development of highly intelligent multistep commutation strategies. The solution to this problem has been made possible by using powerful digital devices that are now readily available in the market.



 Gyugi and B. Pelly, Static Power Frequency Changers: Theory, Performance and Applications. New York: Wiley, 1976.

  • Brandt, “Der Netztaktumrichter,” Bull. ASE, vol. 62, no. 15, pp. 714–727, July 1971.
  • Popov, “Der Direktumrichter mit zyklischer Steuerung,” Elektrie, vol. 29, no. 7, pp. 372– 376, 1975.
  • Stacey, “An unrestricted frequency changer employing force commutated thyristors,” in Proc. IEEE PESC’76, 1976, pp. 165–173.
  • Jones and B. Bose, “A frequency step-up cycloconverter using power transistors in inverse-series mode,” Int. J. Electron., vol. 41, no. 6, pp. 573–587, 1976.
  • MATRIX Converter

Control for Grid-Connected and Intentional Islanding Operations of Distributed Power Generation


Intentional islanding describes the condition in which a microgrid or a portion of the power grid, which consists of a load and a distributed generation (DG) system, is isolated from the remainder of the utility system. In this situation, it is important for the microgrid to continue to provide adequate power to the load. Under normal operation, each DG inverter system in the microgrid usually works in constant current control mode in order to provide a preset power to the main grid. When the microgrid is cut off from the main grid, each DG inverter system must detect this islanding situation and must switch to a voltage control mode. In this mode, the microgrid will provide a constant voltage to the local load. This paper describes a control strategy that is used to implement grid-connected and intentional-islanding operations of distributed power generation. This paper proposes an intelligent load-shedding algorithm for intentional islanding and an algorithm of synchronization for grid reconnection.



  1. Distributed generation (DG)
  2. Grid-connected operation
  3. Intentional-islanding operation
  4. Islanding detection
  5. Load shedding
  6. Synchronization





grid connected  

Fig. 1. Schematic diagram of the grid connected inverter system.



grid-connected to intentional-islanding operation.

Fig. 2. From grid-connected to intentional-islanding operation.

Synchronization for grid reconnection.
Fig. 3. Synchronization for grid reconnection.

Phase voltage (top) without and (bottom) with the synchronization algorithm.

Fig. 4. Phase voltage (top) without and (bottom) with the synchronization algorithm.

Fig. 5. Phase voltage
Va without the load-shedding algorithm.

Phase voltage Va with the load-shedding algorithm

Fig. 6.Phase voltage Va with the load-shedding algorithm.


 Through this paper, the control, islanding detection, load shedding, and reclosure algorithms have been proposed for the operation of grid-connected and intentional-islanding DGs. A controller was designed with two interface controls: one for grid connected operation and the other for intentional islanding operation. An islanding-detection algorithm, which was responsible for the switch between the two controllers, was presented. The simulation results showed that the detection algorithm can distinguish between islanding events and changes in the loads and can apply the load-shedding algorithms when needed. The reclosure algorithm causes the DG to resynchronize itself with the grid. In addition, it is shown that the response of the proposed control schemes is capable of maintaining the voltages and currents within permissible levels during grid connected and islanding operation modes. The experimental results showed that the proposed control schemes are capable of maintaining the voltages within the standard permissible levels during grid connected and islanding operation modes. In addition, it was shown that the reclosure algorithm causes the DG to resynchronize itself with the grid.



  • Jayaweera, S. Galloway, G. Burt, and J. R. McDonald, “A sampling approach for intentional islanding of distributed generation,” IEEE Trans. Power Syst., vol. 22, no. 2, pp. 514– 521, May 2007.
  • M. Guerrero, J. C. Vásquez, J. Matas, M. Castilla, and L. García de Vicuña, “Control strategy for flexible microgrid based on parallel lineinteractive UPS systems,” IEEE Trans. Ind. Electron., vol. 56, no. 3, pp. 726–736, Mar. 2009.
  • Fuangfoo, T. Meenual,W.-J. Lee, and C. Chompoo-inwai, “PEA guidelines for impact study and operation of DG for islanding operation,” IEEE Trans. Ind. Appl., vol. 44, no. 5, pp. 1348–1353, Sep./Oct. 2008. 156 IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL. 58, NO. 1, JANUARY 2011
  • Carpaneto, G. Chicco, and A. Prunotto, “Reliability of reconfigurable distribution systems including distributed generation,” in Proc. Int. Conf. PMAPS, 2006, pp. 1–6.
  • IEEE Recommended Practice for Utility Interface of Photovoltaic (PV) Systems, IEEE Std 929-2000, 2000, p. i.

Simulation a Shunt Active Power Filter using MATLAB /SIMULINK


 Along with increasing demand on improving power quality, the most popular technique that has been used is Active Power Filter (APF); this is because APF can easily eliminate unwanted harmonics, improve power factor and overcome voltage sags. This paper will discuss and analyze the simulation result for a three-phase shunt active power filter using MATLAB/SIMULINK program. This simulation will implement a non-linear load and compensate line current harmonics under balance and unbalance load. As a result of the simulation, it is found that an active power filter is the better way to reduce the total harmonic distortion (THD) which is required by quality standards IEEE-519.



  1. APF
  2. d-q theorem,
  3. THD
  4. Power Quality
  5. ADS
  6. Instantaneous Power theory




shunt active power filter Fig.1. Diagram illustrating component of shunt connected active filter with the waveform showing cancellation of harmonics from an ASD load.



Fig. 2. Three phase line voltage  

                               Fig. 3. Three phase line current

Fig. 4. Three phase load current

                                          Fig. 5. Active filter current

Fig. 6. Line current for phase A

Fig. 7. Load current for phase A


Fig. 8. Active filter current for phase A

Fig. 9. THD for line current

Fig. 10. THD for load current



The Increasing usage of non-linear load in electrical power system which will produce the current and voltage harmonics and associate harmonics problem in power system become more serious and directly affecting the power quality. Conventional way of harmonics elimination by using passive filter might suffer from parasitic problem. It has been shown that three phase active filter based on p-q theory can be implemented for harmonic mitigation and power factor correction. Harmonics mitigation carried out by the active filter meets the IEEE-519 standard requirements.



 Emadi, A. Nasiri, and S. B. Bekiarov, “Uninterruptible Power Supplies and Active Filter”, Florida, 2005, pp. 65-111.

  • W. Hart, “Introduction to Power Electronics”, New Jersey, 1997, pp. 291-335.
  • McGranaghan, “Active Filter Design and Specification for Control of Harmonics in Industrial and Commercial Facilities”, 2001.
  • Round, H. Laird and R. Duke, “An Improved Three-Level Shunt Active Filter”, 2000.
  • Lev-Ari, “Hilbert Space Techniques for Modeling and Compensation of Reactive Power in Energy Processing Systems”, 2003.

Modeling And Simulation For Voltage Sags/Swells Mitigation Using Dynamic Voltage Restorer (Dvr)


 This project describes the problem of voltage sags and swells and its severe impact on non linear loads or sensitive loads. The dynamic voltage restorer (DVR) has become popular as a cost effective solution for the protection of sensitive loads from voltage sags and swells. The control of the compensation voltages in DVR based on dqo algorithm is discussed. It first analyzes the power circuit of a DVR system in order to come up with appropriate control limitations and control targets for the compensation voltage control. The proposed control scheme is simple to design. Simulation results carried out by Matlab/Simulink verify the performance of the proposed method .


  1. DVR
  2. Voltage sags
  3. Voltage swells
  4. Sensitive load





Figure 1: Schematic diagram of DVR




Fig.2 Flow Chart Of Feed forward Control Technique For DVR Based Ob DQO Transformation

Three-phase voltages sag:

Figure 3. Three-phase voltages sag: (a)-Source voltage,(b)-Injected voltage, (c)-Load voltage

Single-phase voltage sag

Figure.4. Single-phase voltage sag: (a)-Source voltage, (b)-Injected voltage, (c)-Load voltage

Three-phase voltages swell

Figure.5.Three-phase voltages swell: (a)-Source voltage, (b)-Injected voltage, (c)-Load voltage

Two-phase voltages swell

Figure. 6. Two-phase voltages swell: (a)-Source voltage, (b)-Injected voltage, (c)-Load voltage



 The modeling and simulation of a DVR using MATLAB/SIMULINK has been presented. A control system based on dqo technique which is a scaled error of the between source side of the DVR and its reference for sags/swell correction has been presented. The simulation shows that the DVR performance is satisfactory in mitigating voltage sags/swells.



  • G. Hingorani, “Introducing Custom Power in IEEE Spectrum,” 32p, pp. 4l-48, 1995.
  • IEEE Std. 1159 – 1995, “Recommended Practice for Monitoring Electric Power Quality”.
  • Boonchiam and N. Mithulananthan, “Understanding of Dynamic Voltage Restorers through MATLAB Simulation,” Thammasat Int. J. Sc. Tech., Vol. 11, No. 3, July-Sept 2006.
  • G. Nielsen, M. Newman, H. Nielsen,and F. Blaabjerg, “Control and testing of a dynamic voltage restorer (DVR) at medium voltage level,” IEEE Trans. Power Electron., vol. 19, no. 3,p.806, May 2004.
  • Ghosh and G. Ledwich, “Power Quality Enhancement Using Custom Power Devices,” Kluwer Academic Publishers, 2002.
  • Modeling And Simulation For Voltage Sags/Swells Mitigation Using Dynamic Voltage Restorer (Dvr)

Single Phase Grid-Connected Photovoltaic Inverter for Residential Application with Maximum Power Point Tracking


This article proposes a topology for single-phase two stage grid connected solar photovoltaic (PV) inverter for residential applications. Our proposed grid-connected power converter consists of a switch mode DC-DC boost converter and a H-bridge inverter. The switching strategy of proposed inverter consists with a combination of sinusoidal pulse width modulation (SPWM) and square wave along with grid synchronization condition. The performance of the proposed inverter is simulated under grid connected scenario via PSIM. Furthermore, the intelligent PV module system is implemented using a simple maximum power point tracking (MPPT) method utilizing power balance is also employed in order to increase the systems efficiency.



  1. Photovoltaic
  2. DC-DC Boost Converter
  3. MPPT
  4. SPWM
  5. Grid Connected
  6. Power Electronics
  7. Grid Tie Inverter(GTI)



Figure 1. Block diagram of two-stage grid connected PV system



Figure 2. Output voltage of the inverter without filtering

Figure 3. Output current of the inverter

Figure 4. Output voltage after connected to grid

Figure 5. Output real power

Figure 6. Output voltage’s FFT (a) before filtering and (b) after filtering



The main purpose of this paper is to establish a model for the grid-connected photovoltaic system with maximum power point tracking function for residential application. A single phase two-stage grid-connected photovoltaic inverter with a combination of SPWM and square-wave switching strategy is designed using PSIM. In the proposed design, an MPPT algorithm using a boost converter is designed to operate using (P&O) method to control the PWM signals of the boost converter, which is adapted to the maximum power tracking in our PV system. Instead of using line frequency transformer at the inverter output terminals, a DC-DC boost converter is used between solar panel and inverter that efficiently amplify the 24V PV arrays output into 312V DC, which is then transformed into line frequency (50Hz) sinusoidal ac 220V rms voltage by the inverter and thereby reducing the system losses and ensures high voltage gain and higher efficiency output. The simulation results show that the proposed grid connected photovoltaic inverter trace the maximum point of solar cell array power and then converts it to a high quality ripple free sinusoidal ac power with a voltage THD below 0.1% which is very much lower than IEEE 519 standard. The simulation also confirms the proposed photovoltaic inverter can be applied as a GTI and able to supplies the AC power to utility grid line with nearly unity power factor.



[1] W. Xiao, F. F. Edwin, G. Spagnuolo, J. Jatsvevich, “Efficient approach for modelling and simulating photovoltaic power system” IEEE Journal of photovoltaics., vol. 3, no. 1, pp. 500-508, Jan. 2013.

[2] E. Roman, R. Alonso, P. Ibanez, S. Elorduizapatarietxe, D. Goitia, “ Intelligent PV module for grid connected PV system,” IEEE Trans. Ind. Elecron., vol. 53, no. 4, pp. 1066-1072, Aug. 2006.

[3] J. A. Santiago-Gonzalez, J. Cruz-Colon, R. otero-De-leon, V. lopez- Santiago, E.I. Ortiz-Rivera, “ Thre phase induction motor drive using flyback converter and PWM inverter fed from a single photovoltaic panel,” Proc. IEEE PES General Meeting, pp. 1-6, 2011.

[4] M. D. Goudar, B. P. Patil, and V. Kumar, “ Review of topology for maximum power point tracking based photovoltaic interface,” International Journal of Research in Engineering Science & Technology, vol.2, Issue 1, pp. 35-36, Feb 2011.

[5] S. Kjaer, J. Pedersen, and F. Blaabjerg, “A review of single-phase gridconnected inverters for photovoltaic modules,” Industry Applications, IEEE Transactions, vol. 41, no. 5, pp. 1292 – 1306, Sept. – Oct. 2005.


Improved Particle Swarm Optimization For Photovoltaic System Connected To The Grid With Low Voltage Ride Through Capability


 Grid connected photovoltaic (PV) system encounters different types of abnormalities during grid faults; the grid side inverter is subjected to three serious problems which are excessive DC link voltage, high AC currents and loss of grid-voltage synchronization. This high DC link voltage may damage the inverter. Also, the voltage sags will force the PV system to be disconnected from the grid according to grid code. This paper presents a novel control strategy of the two-stage three-phase PV system to improve the Low-Voltage Ride-Through (LVRT) capability according to the grid connection requirement. The non-linear control technique using Improved Particle Swarm Optimization (IPSO) of a PV system connected to the grid through an isolated high frequency DCeDC full bridge converter and a three-phase three level neutral point clamped DC-AC converter (3LNPC2) with output power control under severe faults of grid voltage. The paper, also discusses the transient behavior and the performance limit for LVRT by using a DC-Chopper circuit. The model has been implemented in MATLAB/SIMULINK. The proposed control succeeded to track MPP, achieved LVRT requirements and improving the quality of DC link voltage. The paper show


  1. Particle swarm optimization
  2. Maximum power point tracking
  3. PV system
  4. High frequency isolated converter
  5. Low voltage ride through
  6. Grid




Fig. 1. Block diagram of the PV system connected to the grid.


Fig. 2. PV module characteristics (a) Current-voltage characteristics (b) power-voltage characteristics.

Fig. 3. Behavior of PV array under normal condition using IPSO.

Fig. 4. DC-link voltage under normal condition using IPSO.

Fig. 5. Behavior of PV array under normal condition using IC.

Fig. 6. DC-link voltage under normal condition using IC.

Fig. 7. Behavior of grid connected inverter system under normal operation.


Fig. 8. The grid voltage fault.

Fig. 9. Behavior of PV array under fault condition.

Fig. 10. DC-link voltage under fault condition.

Fig. 11. Behavior of grid connected inverter system under fault condition.

Fig. 12. Behavior of PV array with LVRT capability.

Fig. 13. DC-link voltage during a grid fault with LVRT capability.

Fig. 14. Behavior of grid connected inverter system with LVRT capability.


Based on the existing grid requirements, this paper discussed the potential of a two-stage three-phase grid-connected PV system operating in grid fault condition. The power control method proposed in this paper is effective when the system is under grid fault operation mode. It can be concluded that the future three-phase grid-connected PV systems are ready to be more active and more “smart” in the regulation of power grid.

Non-linear robust control technique using IPSO control is implemented for MPPT of 100.7 kW PV system connected to the grid. Complete control of both active and reactive powers is implemented using Matlab/Simulink with complete simulation under severe faults of grid voltage. The results show superior behavior of the IPSO; it has a faster dynamic response and better steady-state performance than the traditional algorithm; IC method, thus improving the efficiency of the photovoltaic power generation system. The use of full bridge single phase inverter with a high frequency transformer which combines the advantages of 60 Hz technology and transformer- less inverter technology, achieved MPPT requirements with IPSO. Also, this system overcomes the drawbacks of DC-chopper parameters design.

Two loops of control for the utility-connected 3LNPC2 are implemented which improve the performance of inverter and reduces the harmonics in output voltage. This control, also, increases the power injected to the grid and consequently increases the total efficiency of the system. The results show that the DC chopper circuit is capable of reducing the DC-link voltage below threshold values during the fault and protect it from failure or damage. The IPSO is capable of tracking MPP with LVRT capability included.

An anti-wind up conditioned strategy is used in order to improve the quality on the DC link voltage during and after the grid fault. It succeeds to stop accumulation of the integral part during fault, which helps system to follow up pre-faults values rapidly after clearing the fault. Finally, simulated results have demonstrated the feasibility of the IPSO algorithm and capability of MPPT in grid-connected PV systems with LVRT enhancement.


[1] Ramdan B.A. Koad, Ahmed. F. Zobaa, Comparison between the conventional methods and PSO based MPPT algorithm for photovoltaic systems, Int. J. Electr. Electron. Sci. Eng. 8 (2014) 619e624.

[2] Ali Reza Reisi, Mohammad Hassan Moradi, Shahriar Jamas, Classification and comparison of maximum power point tracking techniques for photovoltaic system: a review, Renew. Sustain. Energy Rev. 19 (2013) 433e443.

[3] N.H. Saad, A.A. Sattar, A.M. Mansour, Artificial neural controller for maximum power point tracking of photovoltaic system, in: MEPCON’2006 Conference, II, El-MINIA, Egypt, 2006, pp. 562e567.

[4] Raal Mandour I. Elamvazuthi, Optimization of maximum power point tracking (MPPT) of photovoltaic system using artificial intelligence (AI) algorithms, J. Emerg. Trends Comput. Information Sci. 4 (2013) 662e669.

[5] Saeedeh Ahmadi, Shirzad Abdi, Maximum power point tracking of photovoltaic systems using PSO algorithm under partially shaded conditions, in: The 2nd Cired Regional Conference, Tehran, Iran, 14, 2014, pp. 1e7.

Final Year Projects for BTech/MTech using Matlab/Simulink in rangareddy

Final Year Projects for BTech/MTech using Matlab/Simulink in rangareddy.

Software Used: Matlab/Simulink
Areas : Power Electronics and Drives, Power Systems, Renewable Energy and sources, etc
Contact us:
email: asokatechnologies@gmail.com
website: www.asokatechnologies.in
Asoka technologies provide Final Year Projects for BTech/MTech using Matlab/Simulink in rangareddy

Final Year Projects ELECTRICAL ENGINEERING is a field of engineering that generally deals with the study and application of electricity, electronics, and electro magnetism. This field first became an identifiable occupation in the later half of the 19th century after commercialization of the electric telegraph, the telephone, and electric power distribution and use. Subsequently, broad casting and recording media made electronics part of daily life. The invention of the transistor, and later the integrated circuit, brought down the cost of electronics to the point they can be used in almost any household object.

Electrical engineering has now subdivided into a wide range of sub fields including electronics, digital computers, power engineering, tele communications, control systems, radio-frequency engineering, signal processing, instrumentation, and microelectronics. Many of these sub disciplines overlap and also overlap with other engineering branches, spanning a huge number of specializations such as hardware engineering, power electronics, electro magnetics & waves, microwave engineering, nanotechnology, electro chemistry, renewable energies, mechatronics, electrical materials science, and many more.
Final Year Projects POWER ELECTRONICS is the application of solid-state electronics to the control and conversion of electric power. The first high power electronic devices were mercury-arc valves. In modern systems the conversion is performed with semiconductor switching devices such as diodes, thyristors and transistors, pioneered by R. D. Middlebrook and others beginning in the 1950s. In contrast to electronic systems concerned with transmission and processing of signals and data, in power electronics substantial amounts of electrical energy are processed. An AC/DC converter (rectifier) is the most typical power electronics device found in many consumer electronic devices, e.g. television sets, personal computers, battery chargers, etc. The power range is typically from tens of watts to several hundred watts. In industry a common application is the variable speed drive (VSD) that is used to control an induction motor. The power range of VSDs start from a few hundred watts and end at tens of megawatts.

Final Year Projects