MATLAB-Simulink Model Based Shunt Active Power Filter Using Fuzzy Logic Controller to Minimize the Harmonics

 ABSTRACT:

 The problem of quality electrical energy provided to the users has arisen. This is due to the increasing presence in network of nonlinear loads.They constitute a harmonic pollution source of the network, which generate many disturbances, and disturb the optimal operation of electrical equipments. This work, proposed a solution to eliminate the harmonics introduced by the nonlinear loads. It presents the analysis and simulation using Matlab Simulink of a active power filter (APF) compensating the harmonics and reactive power created by nonlinear loads in steady and in transients. The usefulness of the simulation approach to APF is demonstrated , have a better power quality insight using Matlab Simulink in order to develop new fuzzy logic controller based active power filter.

KEYWORDS:

1.      Active Power Filters

2.      Harmonics

3.      Fuzzy Logic Controller

4.      MATLAB

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Figure 1 Block diagram of Basic Active Power Filter

EXPECTED SIMULATION RESULTS:

Fig. 2 Three phase voltage and current waveform with non linear load

Fig.3 THD analysis of three phase voltage waveform with nonlinear load

Fig.4 Three phase voltages and current waveform with shunt active power filter with connected fuzzy logic controller

Fig.5 THD analysis of voltages with shunt active power filter using fuzzy logic controller

CONCLUSION:

The paper presents the application of the fuzzy logic controller to control the compensating voltage. The Mamdani max-min approach is used for the fuzzy inference and the defuzzification method, respectively. The design of input and output membership for the fuzzy logic controller is very important for the system performance. The simulation results show that the fuzzy logic controller provides a good performance to control the compensating voltage of shunt active power filter. The %THD of the voltages at PCC point can be followed the IEEE Std. 519-1992.

REFERENCES:

[1] I. J. Pitel, S. N. Talukdar, and P. Wood, “Characterization of Programmed-Waveform Pulse-Width Modulation,” IEEE Transactions on Industry Applications, Vol. IA-16, Sept./Oct. 1980, pp. 707–715.

[2] Wilson E. Kazibwe and Mucoke H. Senduala : “Electric Power Quality Control Techniques”. New York: Van Nostrand Reinhold, 1993

[3] N. Mohan, “A Novel Approach to Minimize Line- Current Harmonics in Interfacing Power Electronics Equipment with 3-Phase Utility Systems”, IEEE Trans on Power Delivery, Vol. 8, July. 1993, pp 1395-1401.

[4] Elias M. Stein, Timonthy S. Murphy : “Harmonic Analysis: Real-Variable Methods, Orthogonality and Oscillatory Integrals.”, Princeton, N.J.: Princeton University Press, 1993

[5] J.S. Lai and T.S. Key, “Effectiveness of harmonic mitigation equipment for commercial office buildings,” IEEE Transactions on Industry Applications, vol.33, no.4, sep 1997, pp. 1065-1110

Simulation Analysis of DVR Performance for Voltage Sag Mitigation

ABSTRACT:

Voltage sag is literally one of power quality problem and it become severe to industrial customers. Voltage sag can cause miss operation to several sensitive electronic equipments. That problem can be mitigating with voltage injection method using custom power device, Dynamic Voltage Restorer (DVR). This paper presents modeling and analysis of a DVR with pulse width modulation (PWM) based controller using Matlab/Simulink. The performance of the DVR depends on the efficiency of the control technique involved in switching the inverter. This paper proposed two control techniques which is PI Controller (PI) and Fuzzy Logic Controller (FL). Comprehensive results are presented to assess the performance of each controller as the best power quality solution. Other factors that also can affect the performance and capability of DVR are presented as well.

KEYWORDS:

1.      Voltage sag

2.      Dynamic Voltage Restore

3.      Pulse Width Modulation (PWM)

4.      PI Controller

5.      Fuzzy Logic Controller

SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Figure1. DVR Modelling using Matlab/Simulink

 EXPECTED SIMULATION RESULTS:

Figure 2. (a) Injection voltage from DVR controlled by PI ; (b) injection voltage controlled by FL

Figure 3. (a) Output voltage at load 1 after injection voltage from DVR controlled by PI; (b) Output voltage at load 1after injection voltage controlled by FL.

Figure 4. (a) Injection voltage from DVR controlled by PI; (b) injection voltage controlled by FL.

Figure 5. (a) Output voltage at load 1 after injection voltage from DVR controlled by PI; (b) Output voltage at load 1after injection voltage controlled by FL.

Figure 6. THD generated when PI controller is applied

Figure 7. THD generated when FL controller is applied.

CONCLUSION:

In this study, the modeling and simulation of DVR controlled by PI and FL Controller has been developed using Matlab/Simulink. For both controller, the simulation result shows that the DVR compensates the sag quickly (70μs) and provides excellent voltage regulation. DVR handles all types, balanced and unbalanced fault without any difficulties and injects the appropriate voltage component to correct any fault situation occurred in the supply voltage to keep the load voltage balanced and constant at the nominal value. Both controllers show an excellent performance and generate low THD (<5%). However, it can be seen that FL Controller gives better performance with THD generated with only 0.64% whilst PI generated 1.68% THD. However, other several factors that can affect the performance of DVR need to be addressed for enhancement of the output voltage. These factors are the energy storage capacity and transformer rating. From the simulation, it clearly shows the importance of these two factors and how they affect the performance of DVR. Therefore, when it comes to implementation, it is crucial to consider these factors, so that the performance of DVR is optimized.

REFERENCES:

[1] Omar, R. Rahim, N.A. “New Control Technique Applied in Dynamic Voltage Restorer for Voltage Sag Mitigation” Industrial Electronics and Applications, 2009. ICIEA 2009. 4th IEEE Conference on.

[2] Faisal, M.F. “Power Quality Management Program: TNB’s Experience”, Distribution Engineering, TNB 2005.

[3] Wahab, S.W. Yusof, A.M. “Voltage Sag Mitigation Using Dynamic Voltage Restorer (DVR) System, ELEKTRIKA, 8(2),2006, 32-37.

[4] IEEE Standard Board (1995), “IEEE Std. 1159-1995”, IEEE  Recommended Practice for Monitoring Electric Power Quality”. IEEE Inc. New York.

[5] Kim H. “Minimal Energy Control for a Dynamic Voltage Restorer”, In proceedings of the Power Conversion Conference, Osaka, Japan, 2002, pp. 428-433.

Photovoltaic Based Dynamic Voltage Restorer with Energy Conservation Capability using Fuzzy Logic Controller

ABSTRACT:

In this paper, a Photovoltaic based Dynamic Voltage Restorer (PV-DVR) is proposed to handle deep voltage sags, swells and outages on a low voltage single phase residential distribution system. It can recover sags up to 10%, swells up to 190% of its nominal value. Otherwise, it will operate as an Uninterruptable Power Supply (UPS) when the utility grid fails to supply. It is also designed to reduce the usage of utility power, which is generated from nuclear and thermal power stations. A series injection transformer is connected in series with the load when restoring voltage sag and swell and it is reconfigured into parallel connection using semiconductor switches when it is operating in UPS and power saver mode. The use of high step up dc-dc converter with high-voltage gain reduces the size and required power rating of the series injection transformer. It also improves the stability of the system. The Fuzzy Logic (FL)  controller with two inputs maintains the load voltage by detecting  the voltage variations through d-q transformation technique.  Simulation results have proved the ability of the proposed DVR  in mitigating the voltage sag, swell and outage in a low voltage single phase residential distribution system.

KEYWORDS:

1.      Dynamic Voltage Restorer

2.      Photovoltaic

3.      Voltage Sag

4.      Voltage Swell

5.      Outages

6.      High Step up dc-dc Converter

7.      Fuzzy Logic Controller

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Structural block diagram of the proposed system.

EXPECTED SIMULATION RESULTS:

(a)     Supply Voltage

(b)     Injected Voltage

(c)     Load Voltage

(d)     Load Current

(e) Load voltage THD

Fig. 2. Supply voltage, Injected voltage, Load voltage, Load Current and

Fig. 3. Load Voltage with PI controller

(a)     PV array output voltage without low power boost converter

(b) PV array output voltage with low power boost converter

Fig. 4. PV array output voltage without and with boost converter

Fig. 5. Output voltage of the high step up DC-DC converter

CONCLUSION:

This paper proposed a new PV based DVR to reduce the energy consumption from the utility grid. The design of a Dynamic Voltage Restorer (DVR) which incorporates a PV array module with low and high power boost converters as a DC voltage source to mitigate voltage sags, swells and outages in low voltage single phase distribution systems using FL controller has been presented. The modeling and simulation of the proposed PV based DVR using MATLAB simulink has been presented. The FL controller utilizes the error signal from the comparator to trigger the switches of an inverter using a sinusoidal PWM scheme. The proposed DVR utilizes the energy drawn from the PV array and the utility source to charge the battries during normal operation. The stored energies in battery are converted to an adjustable single phase ac voltage for mitigation of voltage sag, swell and outage. The simulation result shows that the PV based DVR with FL controller gives better dynamic performance in mitigating the voltage variations. The proposed DVR is operated in:

Standby Mode: when the PV array voltage is zero and the inverter is not active in the circuit to keep the voltage to its nominal value.

Active Mode: when the DVR senses the sag, swell and outage. DVR reacts fast to inject the required single phase compensation voltages.

Bypass Mode: when DVR is disconnected and bypassed in case of maintenance and repair.

Power Saver mode: when the PV array with low step-up dc-dc converter output power is enough to handle the load.

Further work will include a comparison with laboratory experiments on a low voltage DVR in order to compare simulation and experimental results. The multiple functions of DVR require further investigation.

REFERENCES:

[1] H.Ezoji, A.Sheikholeslami, M.Tabasi, and M.M.Saeednia, “Simulation of dynamic voltage restorer using hysteresis voltage control,” European journal of scientific research, vol. 27, pp. 152-166, Feb 2009.

[2] F.A.L.Jowder, “Modeling and simulation of different system topologies for dynamic voltage restorer using simulink,” in proc. EPECS ’09, 2009, p. 1-6.

[3] R.Strzelecki, and G.Benysek, “Control strategies and comparison of the dynamic voltage restorer,” in proc. PQ ‘08, 2008, p. 79-82.

[4] P.Boonchiam, and N.Mithulananthan, “Understanding of dynamic voltage restorers through MATLAB simulation,” Thammasat Int. J. Sc. Tech., Vol. 11, No.3, pp. 1-6, Sep 2006.

[5] K.C.Bayinder, A.Teke, and M.Tumay, “A Robust control of dynamic voltage restorer using fuzzy logic,” in proc. ACEMP ’07, 2007, p.55

Performance Improvement of DVR by Control of Reduced-Rating with A Battery Energy Storage

ABSTRACT:

Voltage injection methods for DVRs (Dynamic Voltage Restorers) and operating modes are resolved in this paper. Using fuzzy logic control DVR with dc link& with BESS systems are operated. Power quality problems mainly harmonic distortion, voltage swell & sag are decreased with DVR using Synchronous Reference Theory (SRF theory) with the help of fuzzificaton waveforms are observed.

KEYWORDS:

1.      Dynamic Voltage Restorer

2.      Unit Vector

3.      Power quality

4.      Harmonic distortion

5.      Voltage Sag

6.      Voltage Swell

7.      Fuzzy logic controller

8.      Matlab/simulink software

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig.1.Block Diagram of DVR

 EXPECTED SIMULATION RESULTS:

Fig.2 Voltage waveforms at common coupling point (PCC) and load during harmonic distortion

Fig.3. the dc voltage injection from BESS connected DVR system at voltage swelling period

Fig.4. DVR waveforms during voltage sag at time of voltage in phase injection

Fig.5 Amplitude of load voltages and PCC voltages w.r.t time

Fig 6.DVR waveforms during harmonic distortion at the time of voltage in phase injection

CONCLUSION:

By applying different voltage injection schemes the role of DVR has been shown with a latest control technique. The presentation of DVR has been balanced with various schemes with a reduced-rating VSC. For getting the control of DVR, the reference load voltages have been determined with the help of unit vectors, for which the error of voltage insertion is reduced. By using SRF theory the reference DVR voltages have been determined. In the end, the result derived are that the in phase voltage insertion with PCC voltage reduces the DVR rating but at the same time at its DC bus the energy source is wasted.

REFERENCES:

[1] Math H.J. Bollen, Understanding Power Quality Problems- Voltage Sags and Interruptions, IEEE Press, New York, 2000.

[2] A. Ghosh and G. Ledwich, Power Quality Enhancement using Custom Power devices, Kluwer Academic Publishers, London, 2002

[3] Eddy C. Aeloíza, Prasad N. Enjeti, Luis A. Morán, Oscar C. Montero- Hernandez, and Sangsun Kim, “Analysis and Design of a New Voltage Sag Compensator for Critical Loads in Electrical Power Distribution Systems”, IEEE Trans. on Ind. Appl., vol. 39, no. 4, pp 1143-1150, Jul/Aug 2003.

[4] J. W. Liu, S.S. Choi and S. Chen, “Design of step dynamic voltage regulator for power quality enhancement”, IEEE Trans. on Power Delivery, vol. 18, no.4, pp. 1403 – 1409, Oct. 2003.

[5] Arindam Ghosh, Amit Kumar Jindal and Avinash Joshi, “Design of a capacitor supported dynamic voltage restorer for unbalanced and distorted loads” IEEE Trans. on Power Delivery, vol.19, no. 1, pp. 405-413, Jan 2004.