Artificial Neural Network based Three Phase Shunt Active Power Filter

Artificial Neural Network based Three Phase Shunt Active Power Filter

ABSTRACT:

This work describes artificial neural network (ANN) based control algorithm for three phase three wire shunt active power filter (SAPF) to compensate harmonics and improve power quality. System consists of three phase insulated gate bipolar transistors IGBT based current controlled voltage source inverter (CC-VSI), series coupling inductor and self supported DC bus. Increasing application of non-linear loads causes power quality problem. SAPF is one of the possible configurations to improve power quality. Traditional SAPF have PLL based unit template generator for extraction of fundamental signal. Traditional PLL needs to be tuned to obtain optimal performance for frequency estimation. It requires initial assumptions for fundamental frequency and minimum frequency. With varying frequency, it can’t be dynamically tuned for optimal performance. A new ANN based fundamental extraction based on Lavenberg Marquardt back propagation algorithm is proposed. Proposed SAPF is modeled in Simulink environment. Simulated results show the capability of proposed system.

KEYWORDS:

1.      Shunt Active Power Filter

2.      Artificial Neural Networks

3.      Indirect Current Control Technique

4.      Power Quality

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig.1. Proposed system configuration block with SAPF

 EXPECTED SIMULATION RESULTS:

Fig.2. Source voltages

Fig.3. Unbalanced load voltages

Fig.4. Unbalanced load currents

 Fig.5. Simulation result for proposed system under non linear with

unbalance load condition

Fig.6. DC link voltage

 Fig.7. Active power

Fig.8. Reactive power

Fig.9. Power factor

Fig.10. Harmonic spectrum of load current before compensation for three phase SAPF with non linear load

Fig.11. Harmonic spectrum of source currents (phase a, phase b phase c respectively) after compensation for ANN based three phase APF with non linear load

Fig.12. Harmonic spectrum of source currents (phase a) after compensation for ANN based three phase APF with non linear load with unbalance

CONCLUSION:

ANN based phase-locking scheme has been proposed in this paper to control three phase-three wire shunt APFs. Widrow-Hoff weights updating algorithm has been incorporated to reduce calculation time in estimation of harmonic components. To validate effectiveness of proposed approach for real-time applications, indirect current control theory based controller has been developed. Design parameters of power circuit and control circuit have been calculated and robustness of proposed system has been established with Matlab/Simulink. Simulation result and spectral response show that, obtained source current THDs is below 5% as prescribed by IEEE-519 standard. Dynamic performance of proposed approach has been found satisfactory under sudden change in load and frequency.

REFERENCES:

[1]   P. Kumar and D.K. Palwalia, “Decentralized autonomous hybrid renewable power generation”, Journal of Renew. Energy, pp. 1-18, 2015.

[2]   W. Dai, T. Huang, and N. Lin, “Design of single-phase shunt active power filter based on ANN”, IEEE Int. Symp. on Ind. Electron., pp. 770-774, 2007.

[3]   H. Akagi, Y. Kanazawa, and A. Nabae, “Instantaneous reactive power compensators comprising switching devices without energy storage components,” IEEE Trans. Ind. Applicat., vol. IA-20, pp. 625–630, 1984.

[4]   H. Akagi and A. Nabae, “The p-q theory in three-phase systems under nonsinusoidal conditions,” Eur. Trans. Elect. Power Eng., vol. 3, no. 1, pp. 27–31, 1993.

[5]   H. Akagi and H. Fujita, “A new power line conditioner for harmonic compensation in power systems,” IEEE Trans. Power Delivery, vol. 10, pp. 1570–1575, 1995.

Application of Neural Networks in Power Quality

Application of Neural Networks in Power Quality

ABSTRACT:

Use of power electronic converters with nonlinear loads produces harmonic currents and reactive power. A shunt active power filter provides an elegant solution to reactive power compensation as well as harmonic mitigation leading to improvement in power quality. However, the shunt active power filter with PI type of controller is suitable only for a given load. If the load is varying, the proportional and integral gains are required to be fine tuned for each load setting. The present study deals with neural network based controller for shunt active power filter. The performance of neural network controller evaluated and compared with PI controller.

KEYWORDS:

1.      Active Power Filter

2.      Neural Networks

3.      Back Propagation Algorithm

4.      Soft Computing.

SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Fig 1. Schematic Diagram of Shunt Active Power Filter

EXPECTED SIMULATION RESULTS:

Fig 2. (a) Waveform of Load Current, Compensating Current, Source Current and Source Voltage for 1kVA with 􀄮=60º and (b) Waveform of Source Voltage and in the phase Source Current of Fig. (a)

CONCLUSION:

The active power filter controller with neural network based controller has been seen to eminently minimize harmonics in the source current when the load demands non sinusoidal current, irrespective of whether the load is fixed or varying. Simultaneously, the power factor at source also becomes the unity, if the load demands reactive power. Thus, neural network based controller is far superior to PI type of controller which requires fine tuning of Kp and Ki every time the load changes. In the present work, the performance of a range of values of the load is considered to robustly test the controller. It has been demonstrated that neural network based controller, therefore, significantly improves the performance of a shunt active power filter.

REFERENCES:

[1]   Laszlo Gyugyi, “Reactive Power Generation and Control by Thyristor Circuits”, IEEE Transactions on Industry Applications, vol. IA-15, no. 5, September/October 1979.

[2]   H. Akagi, Y. Kanazawa, and A. Nabae, “Instantaneous reactive power compensators comprising switching devices without energy storage components,” IEEE Transaction Industrial Applications, vol. IA-20, pp. 625-630, May/June 1984.

[3]   F. Z. Peng, H. Akagi, and A. Nabae, “A study of active power filters using quad series voltage source pwm converters for harmonic compensation,” IEEE Transactions on Power Electronics, vol. 5, no. 1, pp. 9–15, January 1990.

[4]   Conor A. Quinn, Ned Mohan, “Active Filtering of Harmonic Currents in Three-phase, Four-Wire Systems with Three-phase and Single-phase Non-Linear Loads”, IEEE-1992.

[5]   L. A. Morgan, J. W. Dixon, and R. R. Wallace, “A three-phase active power filter operating with fixed switching frequency for reactive power and current harmonic compensation,” IEEE Transactions on Industrial Electronics, vol. 42, no. 4, pp. 402–408, August 1995.

PSO - PI Based DC Link Voltage Control Technique for Shunt Hybrid Active Power Filter

PSO - PI Based DC Link Voltage Control Technique for Shunt Hybrid Active Power Filter

ABSTRACT

In power systems, the intensive use of nonlinear loads causes several power quality problems such as current harmonic pollution. In order to reduce the current harmonic pollution, the shunt hybrid active filter (SHAPF) is the best solution effectively. In shunt hybrid active filter systems SHAPFs, the design of dc link controller is a significant and challenging task due to its impact on the performance and stability of the overall system. The main contribution of this paper is that the particle swarm optimization (PSO) algorithm is applied gains for PI controller which can result in the improved response in terms of response time and overshoot. In proposed control method, the performance results of harmonic compensation are satisfactory. Theoretical analyses and simulation results are obtained from an actual industrial network model in PSCAD. The simulation results are presented for proposed system in order to demonstrate that the harmonic compensation performance meets the IEEE-519 standard.

KEYWORDS

1.      DC link controller

2.      Harmonics

3.      Particle swarm optimization

4.      Power quality

5.      PSCAD

6.      Shunt hybrid active power filter

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

Figure 1. SHAPF Power System

EXPECTED SIMULATION RESULTS

Figure 2 Comparison of PI, PID and PSO based PI controller for DC link

Control

Figure 3 Three phase Source Voltages, Load – M-SHAPF - Source

Currents, SHAPF DC link Voltage

Figure 4 Source -Load-M-SHAPF active power, Source -Load-M-SHAPF

reactive power

CONCLUSION

The intensive use of nonlinear loads causes several power quality problems such as current harmonic pollution. In order to reduce the current harmonic pollution, the shunt hybrid active filter (SHAPF) is the best solution effectively. In shunt hybrid active filter systems (SHAPF)s, the design of dc link controller is a significant and challenging task due to its impact on the performance and stability of the overall system. On account of the limitations between existing literatures, the purpose of this paper is that PSO algorithm has been proposed to adapt the dc link controller gains of the SHAPF. In this paper, the particle swarm optimization (PSO) algorithm is applied gains for PI controller which can result in the improved response in terms of response time and overshoot. In proposed control method, the performance results of harmonic compensation are satisfactory. Theoretical analyses and simulation results are obtained from an actual industrial network model in PSCAD. The simulation results are presented for proposed system in order to demonstrate that the harmonic

REFERENCES

[1]   B. Soudan and M. Saad, “An evolutionary dynamic population size PSO implementation,” in Information and Communication Technologies: From Theory to Applications, 2008. ICTTA 2008. 3^rd International Conference on, 2008, pp. 1–5.

[2]   J. Kennedy, “Particle swarm optimization” IEEE International Conference on Neural Network , pp. 1942 - 1948 , 1995. doi: 10.1109/ICNN.1995.488968.

[3]   Chien-Hung Liu and Yuan-Yih Hsu, “Design of a Self-Tuning PI Controller for a STATCOM Using Particle Swarm Optimization,” IEEE Transactions on Industrial Electronics, vol. 57, no. 2, pp. 702– 715, Feb. 2010.

[4]   J. Turunen, M. Salo and H. Tuusa, “Comparison of three series hybrid active power filter topologies”, 11th International Conference on. Harmonics and Quality of Power, pp. 324–329, Sept. 2004. doi: 10.1109/ICHQP.2004.1409375.

[5]   M. A. Mulla, C. Rajagopalan, A. Chowdhury,”Compensation of three-phase diode rectifier with capacitive filter working under unbalanced supply conditions using series hybrid active power filter”, IET Power Electronics, vol.7, (6), pp. 1566–1577, 2014, doi: 10.1049/iet-pel.2013.0605.

PI tuning of Shunt Active Filter using GA and PSO Algorithm

PI tuning of Shunt Active Filter using GA and PSO Algorithm

ABSTRACT

In this paper p-q theory is used as control technique for active filter which minimizes the lower order harmonics in the power system. This method improves the supply side current quality. The control strategy uses the PI controller for controlling the DC link voltage in the system. The PI controller parameters are selected generally with intuitive method of PI tuning. Iteratively it is identified that PI parameters highly affect in the THD of the system input current. So there is a need of optimal selection of parameters of the PI controller. In this method Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) are used for selection of optimal parameters for PI controller.

KEYWORDS

1.      Active Filters

2.      Genetic Algorithm

3.      Optimisation Techniques

4.      P-q theory

5.      Particle Swarm Optimisation

SOFTWARE: MATLAB/SIMULINK

SIMULINK MODEL:

Fig.1 Simulink model of shunt active filter

EXPECTED SIMULATION RESULTS

Fig.2 current waveform for before compensation

Fig.3 source voltage and source current after compensation for GA

Fig. 4 compensation current and pulses produced by controller

Fig.5 source voltage and source current after compensation for PSO

Fig.6 compensation current and pulses produced by controller for PSO

CONCLUSION

The shunt active filter is designed with the optimization algorithms to tune the parameters of PI controllers. The values are selected optimally by using the GA and PSO algorithm. GA requires more converging time compared to PSO due to many operations. PSO converges with lesser THD compared with GA where the number population also less compared to GA. So PSO delivers the best results compared to GA and implementation also simple.

REFERENCES:

[1]   Ned Mohan 2002, ‘Power Electronics: Converters, Applications, and Design’ 3rd Edition’, Wiley publications _

[2]   Bhattacharya,S Frank,TM, Divan,DM & Banerjee, B 1998, ‘Active filter system implementation’, IEEE Ind. Appl. Mag., 4(5): 47–63. _

[3]   Bhattacharya, C. Chakraborty, & Bhattacharya,S 2009, ‘Current compensation in shunt type active power filters’, IEEE Ind. Electron. Mag., 3(3): 38– 49.

[4]   Bhim Singh, Kamal Al-Haddad & Ambrish Chandra 1999, ‘A New Control Approach to 3-phase Active Filter for Harmonics and Reactive Power Compensation’, IEEE Trans. on Power Systems, 46(5):133– 138.

[5]   Davood yazdani, Alireza Bakhshai & Praveen K.Jain 2010, ‘A Threephase Adaptive Notch filter based Approach to Harmonic /Reactive current extraction and harmonic decomposition’, IEEE Transactions on Power electronics, 25(4): 914-922.

Particle Swarm Optimization Based Shunt Active Harmonic Filter for Harmonic Compensation

Particle Swarm Optimization Based Shunt Active Harmonic Filter for Harmonic Compensation

ABSTRACT

This paper presents a performance evaluation of Shunt Active Harmonic Filter (SAHF) for harmonic compensation, using Particle Swarm Optimization algorithm for DC link voltage regulation. Particle Swarm Optimization algorithm is used to search for the optimal PI control parameters. The simulation results show that the performance of Shunt Active Harmonic Filter (SAHF), where current is generated using instantaneous real and reactive power(p-q) theory, using PSO technique for six pulse controlled rectifier under different firing angles is simple in structure and very effective for harmonic compensation. The simulation is done with the help of MATLAB-SIMULINK tool box.

KEYWORDS

1.      Shunt Active Harmonic Filter

2.      PI controller

3.      Hysteresis Current Controller

4.      P-q theory

5.      PSO

6.      Controlled rectifier

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Proposed implementation of PI controller

EXPECTED SIMULATION RESULTS

Fig. 2. Convergence graph of PSO for 􀍲􀍲􀀃firing angle

Fig. 3. FFT analysis of source current (phase a) without SAHF.

 Fig. 4. FFT analysis of source current (phase a) of SAHF for 􀍲􀍲firing angle.

Fig. 5. FFT analysis of source current (phase a) of optimized SAHF for 􀍲􀍲firing angle.

CONCLUSION

It can be concluded from the simulation results that with the application of SAHF in parallel to controlled rectifier, harmonics present in the source current are mostly compensated. The DC link voltage is controlled by PI controller, which when optimized using Particle Swarm Optimization Technique further reduces the THD value of source current. The values of THD in phase a, b and c of source current are 30.18%, 31.54%, 31.74% respectively. Further it is analyzed that by optimizing the gains of PI controller the THD values are further reduced from 2.66% to 1.85% for 􀍲􀍲firing angle. Thus we can clearly state that optimization of PI controller using PSO further reduces the harmonics on the source side.

 REFERENCES:

[1]   M.H.J. Bollen, “What is Power Quality?”, Electric Power Systems Research, Vol.66, Iss. 1, pp. 5-14, July 2003.

[2]   H. Akagi, Y. Kanazawa and A. Nabae, ”Theory of Instantaneous Reactive Power and Its Applications”, Transactions of the lEE-Japan, Part B, vol. 103, no.7, 1983, pp. 483-490.

[3]   Ned Mohan 2002, ‘Power Electronics: Converters, Applications, and Design’ 3rd Edition’, Wiley publications.

[4]   F. Z. Peng, H. Akagi and A. Nabae, “A New Approach to Harmonic Compensation in Power System a Combined System of Shunt Passive and Series Active Filter”, IEEE Trans. On Industry App., vol. 27, no. 6, (1990), pp. 983-990.

[5]   Hamadi,A , Rahmani,S & Al-Haddad, K 2010, ‘A hybrid passive filter configuration for VAR control and harmonic compensation’, IEEE Trans. Ind. Electron., 57(7): 2419–2434.