Frequency Adaptive Fractional Order Repetitive Control of Shunt Active Power Filters

ABSTRACT:

Repetitive control which can reach zero steady-state error follow of any periodic signal with known number period, offers active power filters a hopeful accurate current control plan to compensate the harmonic misuse caused by nonlinear loads.

FREQUENCY

However, classical repetitive control cannot exactly satisfy periodic signals of variable density, and would lead to powerful work shame of active power filters.In this paper a partial order repetitive control method at fixed sampling rate is proposed to deal with any periodic signal of variable frequency

FRACTIONAL

where a Lagrange introduction based partial delay filter is used to exact the factional delay items. The combination and search of fractional-order repetitive control systems are also presented. The planned fractional-order repetitive control action fast on-line tuning of the fractional delay and the fast update of the coefficients.

POWER FILTER

And then provides active power filters with a simple but very accurate real-time density adaptive control solution to the elimination of harmonic misuse under grid density change. A case study of single-phase shunt active power filter is organize. Experimental results are provided to display the validity of the planned partial-order repetitive control.

KEYWORDS:

  1. Active power filter
  2. Fractional order
  3. Repetitive control
  4. Frequency variation

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

image001

Fig. 1. Single-phase shunt APF connected to the grid with nonlinear load.

CONTROL SYSTEM

image002

Fig. 2. Dual-loop control scheme for single-phase APF.

 EXPECTED SIMULATION RESULTS:

image003

Fig. 3. Steady-state responses at 50Hz without APF: (a) grid voltage vg and grid current ig, (b) harmonic spectrum of vg, (c) harmonic spectrum of ig.

image004

Fig. 5. Steady-state responses at 50Hz with CRC controlled APF: (a) grid voltage vg and grid current ig, (b) harmonic spectrum of compensated ig.

image005

Fig. 4. Steady-state responses at 49.8Hz with CRC controlled APF: (a) grid voltage vg and grid current ig, (b) compensation current ic, reference current iref and current tracking error, (c) harmonic spectrum of ig.

image006

Fig. 5. Steady-state responses at 49.8Hz with FORC controlled APF: (a) grid voltage vg and grid current ig, (b) compensation current ic, reference current iref and current tracking error, (c) harmonic spectrum of ig.

image007

Fig. 6. Steady-state responses at 50.2Hz with CRC controlled APF: (a) grid voltage vg and grid current ig, (b) compensation current ic, reference current iref and current tracking error, (c) harmonic spectrum of ig.

image008

Fig. 7. Steady-state responses at 50.2Hz with CRC controlled APF: (a) grid voltage vg and grid current ig, (b) compensation current ic, reference current iref and current tracking error, (c) harmonic spectrum of ig.

image009

Fig. 8. Responses to step changes of grid frequency: (a) 49.5Hz→50.5Hz, (b)

50.5Hz→49.5Hz.

image010

Fig. 9. Responses to step load changes at 49.8Hz fundamental frequency: (a) R 15Ω→30Ω, (b) R 30Ω→15Ω.

CONCLUSION:

This paper suggest a density adaptive FORC scheme with fixed sampling rate to track or remove any periodic signal with variable density. Using Lagrange introduction based FD filter to approximate the fractional delay items in RC

APF

the planned FORC offers fast on-line tuning of the fractional delay and the fast update of the coefficients.It provides APFs with a simple but very accurate real-time density adaptive control solution to harmonics misuse compensation under grid density change.

CRC

The stability test of FORC systems are given, which are compatible with those of CRC systems. A study case of FORC based single-phase shunt APF is done.Experiment results show the effectiveness of the planned FORC strategy.

FORC

Furthermore, the Lagrange introduction based FORC can be used in extensive use, such as the feeding currents control of grid connected converters [10]-[11], [27], programmable AC power supply [28], active noise cancelation, and so on.

REFERENCES:

[1] H. Akagi, “New trends in active filters for power conditioning,” IEEE Trans. Ind. Applicat., vol. 32, no. 6, pp. 1312-1322, Nov./Dec. 1996.

[2] H. Akagi, “Active harmonic filters,” Proceedings of the IEEE, vol. 93, no. 12, pp. 2128-2141, Dec. 2005.

[3] Y. Han, L. Xu, M. M. Khan, C. Chen, G. Yao, and L. Zhou, “Robust deadbeat control scheme for a hybrid APF with resetting filter and ADALINE-based harmonic estimation algorithm,” IEEE Trans. Ind. Electron., vol. 58, no. 9, pp. 3893-3904, Sep. 2011.

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

[5] P. Mattavelli and F. P. Marafao, “Repetitive-based control for selective harmonic compensation in active power filters,” IEEE Trans. Ind. Electron., vol. 51, no. 5, pp. 1018-1024, Oct. 2004.

Leave a Reply

Your email address will not be published.