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.

Improved Dynamic Performance of Shunt Active Power Filter Using Particle Swarm Optimization

Improved Dynamic Performance of Shunt Active Power Filter Using Particle Swarm Optimization

ABSTRACT

In this paper, a novel particle swarm optimization (PSO) technique is proposed to tune the proportional-integral (PI) controller gain parameters for enhancing the dynamic performance of the shunt active power filter (APF). The shunt APFs are well established filter to compensate current harmonics, reactive power to maintain the power factor unity. The compensation is highly influenced by the DC-link voltage regulation. The calculated PI controller gain parameters conventionally, are giving satisfactory results under steady state condition of the load. However, tuning of the PI controller parameters under fast changing loads are very difficult. To improve the dynamic performance of the system and optimize the gain parameters of the PI controller, a PSO technique is proposed. The modified p-q theory uses a composite observer filter to extract fundamental component of voltage from the distorted supply voltage for the further process of calculating reference current. A complete comparison of conventional and PSO based PI controller gain tuning have been simulated using MATLAB® Simulink software under different supply voltage and load condition of the system. The results show that the dynamic response is improved with PSO based PI tuning compared to conventional PI tuning.

KEYWORDS

1.      Shunt Active power filters (SAPF)

2.       PI controller

3.       Particle swarm optimization (PSO)

SOFTWARE: MATLAB/SIMULINK

BLOCK  DIAGRAM:

Fig. 1 Optimal design of PI controller gain values using PSO

EXPECTED SIMULATION RESULTS

Fig. 2. Performance of modified p-q control technique under available supply voltage

Fig. 3 FFT analysis of phase a source current under distorted supply voltage

Fig. 4 Simulation results under distorted supply voltage with RC-load

Fig. 5 Harmonic spectrum of phase-a source current after Compensation

Fig. 6 Simulation dynamic performance of the shunt APF

Fig.7 Tuning of PI controller: (a) conventional PI method (b) using PSO technique

CONCLUSION

The performance of the proposed PSO based modified p-q theory has been designed for different types of loads and supply voltage conditions. The modified composite observer filter is an extracted fundamental frequency component of voltage from distorted supply without phase delay which further processed in the calculation of the reference current. The comparison of conventional PI tuning and PSO based tuning is tested for dynamic condition of the load. The proposed control scheme is modelled in MATLAB simulink environment. The simulation results show that the PSO based tuning provide less overshoot, ripples in the DC-link voltage and lesser settling time as compared to convention PI tuning.

 REFERENCES:

[1]   S.S. Adamu, H. S. Muhammad and D.S. Shuaibu, “Harmonics Assessment and Mitigation in Medical Diagnosis Equipment”, IEEE international conference on Awerness Science and Technology (iCAST), pp. 70-75, 2014.

[2]   H. Akagi, “Active harmonic filters,” Proc. IEEE, Vol. 93, no.12, pp.2128-2141, pp.2128-2141, 2005.

[3]   M. H. Bollen, Understanding Power Quality Problems: Voltage Sags and Interruptions, John Wiley & Sons, 1999.

[4]   H. Akagi, E. H. Watanabe, and M. Aredes, Instantaneous Power Theory and Applications to Power Conditioning, Piscataway, NJ: IEEE Press, 2007.

[5]   N. Gupta, S. P. Singh and S. P. Dubey “Neural network based shunt active filter for harmonic and reactive power compensation under non-ideal mains voltage,” In proc. of IEEE Industrial Electronics and Applications (ICIEA), Taiwan, pp. 370-375, 2010.

An Improved Current-Limiting Strategy for Shunt Active Power Filter (SAPF) Using Particle Swarm Optimization (PSO)

An Improved Current-Limiting Strategy for Shunt

Active Power Filter (SAPF) Using Particle Swarm

Optimization (PSO)

ABSTRACT:

The current-limiting strategy for shunt active power filter (SAPF) will be activated automatically, when the compensation-capacity need exceeds the rated capacity. However, the traditional current-limiting strategy cannot realize the comprehensive protection with optimum objectives. The paper firstly reveals the essential of the current-limiting demands for the comprehensive protection of SAPF, namely the limiting control objects: 1) the root mean square (RMS) of the compensation current (mainly for the overheat protection of the IGBT and inductor); 2) the instantaneous wave of compensation current (mainly for the accurate current control and IGBT Icnom specification) and 3) the instantaneous wave of PWM-VSC modulation voltage (for the need of liner close-loop control). Secondly, the paper proposes an improved current-limiting scheme based on particle swarm optimization (PSO) to achieve the two optimization targets: 1) the minimization THD for the grid-side current; 2) the maximization utilization ratio for the capacity of the SAPF. The main advantage lies on the optimum limiting ratios of each harmonic order are calculated in real time respectively to achieve the flexible and liner limiting control. Finally, simulation and experiment verify the effectiveness of the proposed strategy.

KEYWORDS:

1.      Shunt active power filter

2.      Current-limiting demands

3.      Current-limiting strategy

4.      Particle swarm optimization

SOFTWARE:MATLAB/SIMULINK

BLOCK DIAGRAM:

Figure. 1. System mechanism diagram of SAPF.

  

   

EXPECTED SIMULATION RESULTS:

1)      Traditional current-limiting control

Figure. 5. Simulation results of traditional current-limiting strategy.

(a): Modulation voltage without current limitation, (c)(e):Load current and

spectrum analysis, (b): Modulation voltage with traditional current limitation,

(d)(f):Grid-side current Is, output compensation current Ic and spectrum

analysis of Is.

  

2) Optimal current-limiting control using PSO

Figure. 6. Simulation results of the proposed current-limiting strategy.

(a)(c)(e)(g): Simulation waves with the optimum-capacity control strategy,

(b)(d)(f)(h): Simulation waves under the optimum-THD control strategy.

CONCLUSION:

An improved current-limiting strategy based on PSO is proposed to optimize the utilization rate of SAPF or the THD of grid-side current. This strategy takes advantages of the two traditional methods: equal-proportion current-limiting control and truncated current-limiting control. Simulation results prove: the proposed current-limiting scheme can reduce the THD of grid-side current and improve the utilization rate of SAPF effectively, and no extra undesired harmonic will be injected into the power system. Future work will focus on further experiment validation for the effectiveness of the proposed method, especially dynamic performance.

REFERENCES:

[1] Sheng Xu, “An Improved Current-limiting Control Strategy for Shunt Active Power Filter,” in IEEE 8th International Power Electronics and Motion ControlConference, 2016, pp. 1306-1311.

[2] S. J. Chiang and J. M. Chang, “Design and implementation of the parallelable active power filter,” in Annual IEEE Power Electronics Specialists Conference, 1999, pp. 406-411.

[3] P. Mattavelli and F. P. Marafao, “Repetitive-based control for selective harmonic compensation in active power filter,” IEEE Transactions on Industrial Electronics, vol. 51, no. 5, pp. 1018-1024, Oct. 2004.

[4] Y.Tang, P.C.Loh, P.Wang, F.H.Choo, F.Gao, and F.Blaabjerg, “Generalized design of high performance shunt active power filter with output LCL filter,” IEEE Transactions on Industrial Electronics, vol. 59, no. 3, pp. 1443-1452, Mar. 2012.

[5] L. Asiminoaei, C. Lascu, F. Blaabjerg and I. Boldea, “Performance Improvement of Shunt Active Power Filter With Dual Parallel Topology,” IEEE Transactions on Industrial Electronics, vol. 22, no. 1, pp. 247-259, Jan. 2007.