PV-Active Power Filter Combination Supplies Power to Nonlinear Load and Compensates Utility Current

ABSTRACT

The photovoltaic (PV) generation is increasingly popular nowadays, while typical loads require more high-power quality. Basically, one PV generator supplying to nonlinear loads is desired to be integrated with a function as an active power filter (APF).

PV GENERATOR

PV – Active Power Filter In this paper, a three-phase three-wire system, including a detailed PV generator, dc/dc boost converter to extract maximum radiation power using maximum power point tracking, and dc/ac voltage source converter to act as an APF, is presented.

The instantaneous power theory is applied to design the PV-APF controller, which shows reliable performances. The MATLAB/Simpower Systems tool has proved that the combined system can simultaneously inject maximum power from a PV unit and compensate the harmonic current drawn by nonlinear loads.

KEYWORDS

  1. Active power filter (APF)
  2. Instantaneous power theory
  3. Photovoltaic (PV)
  4. Power quality
  5. Renewable energy

SOFTWARE: MATLAB/SIMLINK

BLOCK DIAGRAM:

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Figure 1. proposed design of PV-APF combination.

CONTROL DIAGRAM:

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Figure 2. controller topology of dc/ac VSC in the PV-APF combination.

 EXPECTED SIMULATION RESULTS:

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Figure 3. output power of pv during running time.

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Figure 4. duty cycle and vpv changed by mppt. (a) output voltage of pv unit. (b) duty cycle of mppt.

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Figure 5. utility supplied current waveform.

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Figure 6. utility supplied current and pcc voltage waveform.

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Figure 7. thd in four modes of pv system operation while utility supplies power. (a) dq-current mode. (b) pv-apf mode. (c) apf mode. (d) only utility supplies load.

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Figure 8. pv supplied current waveform.

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Figure 9. real power from the (a) utility, (b) pv unit, and (c) load, while the utility supplies power.

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Figure 10. imaginary power from the (a) utility, (b) pv unit, and (c) load, while the utility supplies power.

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Figure 11. utility received current waveform.

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Figure 12. thd in four modes of pv system operation while utility receives power. (a) dq-current mode. (b) pv-apf mode. (c) apf mode. (d) only utility supplies load.

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Figure 13. real power from the (a) utility, (b) pv unit, and (c) load, while the utility receives power.

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Figure 14. imaginary power from the (a) utility, (b) pv unit, and (c) load, while the utility receives power.

 CONCLUSION:

Regarding the multifunctional DG concept, in this paper, a dynamic grid-connected PV unit is built and the PV-APF combination system with a local controller is proposed. The controller implements two purposes, which are supplying power from the PV unit and filtering the harmonics of the local nonlinear load.

The new controller based on instantaneous power balance has been explained accordingly. The MATLAB/Simpower Systems simulation shows good performances of this controller. The positive influence of MPPT on maximizing PV power output is also validated. The switching among three controllers to dc/ac VSC brings different current waveforms.

PV ACTIVE POWER FILTER

As a result, the conventional dq-current controller should not be applied when PV is connected to a local nonlinear load regarding power-quality viewpoint. Preferably, the PV-APF controller compensates the utility currents successfully. While a PV unit is deactivated, the APF function can still operate.

It is, therefore, technically feasible for these power electronics-interfaced DG units to actively regulate the power quality of the distribution system as an ancillary service, which will certainly make those DG units more competitive.

 REFERENCES:

[1] L. Hassaine, E. Olias, J. Quintero, and M. Haddadi, “Digital power factor control and reactive power regulation for grid-connected photovoltaic inverter,” Renewable Energy, vol. 34, no. 1, pp. 315_321, 2009.

[2] N. Hamrouni, M. Jraidi, and A. Cherif, “New control strategy for 2-stage grid-connected photovoltaic power system,” Renewable Energy, vol. 33, no. 10, pp. 2212_2221, 2008.

[3] M. G. Villalva, J. R. Gazoli, and E. R. Filho, “Comprehensive approach to modeling and simulation of photovoltaic arrays,” IEEE Trans. Power Electron., vol. 24, no. 5, pp. 1198_1208, May 2009.

[4] N. R. Watson, T. L. Scott, and S. Hirsch, “Implications for distribution networks of high penetration of compact _uorescent lamps,” IEEE Trans. Power Del., vol. 24, no. 3, pp. 1521_1528, Jul. 2009.

[5] I. Houssamo, F. Locment, and M. Sechilariu, “Experimental analysis of impact of MPPT methods on energy ef_ciency for photovoltaic power systems,” Int. J. Elect. Power Energy Syst., vol. 46, pp. 98_107, Mar. 2013.

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