Hybrid Structure of Static Var Compensator And Hybrid Active Power Filter (SVC//HAPF) For Medium-Voltage Heavy Loads Compensation

Abstract

In this paper, the structure, modeling, parameter design, and control method are proposed for a new hybrid structure of a static var compensator in parallel with a hybrid active powerfilter (SVC//HAPF). The SVC part of the SVC//HAPF is used to dynamically compensate the reactive power. And, the HAPF part is used to provide harmonic power and small amount of reactive power compensation. Due to the large fundamental voltage drop on coupling the LC part, the active inverter part of the SVC//HAPF has low voltage rating. Meanwhile, the parallel-connected SVC acts as a current divider to reduce the active inverter current. Therefore, the proposed SVC//HAPF shows the great promise in compensating harmonic current and wide-range reactive power with a low (both) voltage and current rating active inverter part. To show the advantages of the proposed SVC//HAPF, simulation comparisons among the active power filter (APF), HAPF, SVC in series with HAPF (SVC−HAPF), and the proposed SVC//HAPF are provided. Finally, experimental results based on the laboratory-scaled hardware prototype are given to show the validity of the SVC//HAPF.

Index Terms

 

1.      Active power filter (APF)

2.       Harmonic current compensation

3.      Hybrid APF (HAPF)

4.      Reactive power compensation

5.      Static var compensator (SVC)

Circuit diagram:

Fig. 1. Circuit configurations of the SVC//HAPF.

Expected Simulation Results:

Fig.2. Waveforms of source current, compensating current, average switching frequency, and trigger signals by using: (a) proportional gain control and (b) hysteresis band control.

 

Fig. 3. Source current harmonic spectrum by using (a) proportional gain control and (b) hysteresis band control.

 

Fig. 4. Waveforms of load voltage, dc-link voltage, load current, source current, and compensating inverter current for harmonic loads current compensation (QLx = 0) and harmonic and reactive power loads compensation by using: (a) APF, (b) HAPF, (c) SVC–HAPF, and (d) the proposed SVC//HAPF.

 

Conclusion

 

In this paper, a new hybrid structure of SVC in parallel with HAPF(SVC//HAPF) in three-phase power system was proposed and discussed as a cost-effective compensator for medium voltage heavy loads compensation. The SVC part was used to dynamically compensate the reactive power, while the HAPF was used to provide harmonic and low fixed amount of reactive power compensation. Moreover, the structure, modeling, operation principle, parameter design, and control method of the SVC//HAPF were proposed and discussed. Finally, the representative simulation and experimental results were given to show that the SVC//HAPF has the great promise in wide reactive power compensation range with both low-voltage and current inverter rating characteristics.

References

[1] A. Hamadi, S. Rahmani, and K. Al-Haddad, “A hybrid passive filter configuration for VAR control and harmonic compensation,” IEEE Trans. Ind. Electron., vol. 57, no. 7, pp. 2419–2434, Jul. 2010.

[2] L. Wang, C. S. Lam, and M. C. Wong, “Design of a thyristor controlled LC compensator for dynamic reactive power compensation in smart grid,” IEEE Trans. Smart. Grid., vol. 8, no. 1, pp. 409–417, Jan. 2017.

[3] J. Chen, X. Zhang, and C.Wen, “Harmonics attenuation and power factor correction of a more electric aircraft power grid using active power filter,” IEEE Trans. Ind. Electron., vol. 63, no. 12, pp. 7310–7319, Dec. 2016.

[4] Z. Shu, M. Liu, L. Zhao, S. Song, Q. Zhou, and X. He, “Predictive harmonic control and its optimal digital implementation for MMC based active power filter,” IEEE Trans. Ind. Electron., vol. 63, no. 8, pp. 5244–5254, Aug. 2016.

[5] X. Sun et al., “Study of a novel equivalent model and a long-feeder simulator-based active power filter in a closed-loop distribution feeder,” IEEE Trans. Ind. Electron., vol. 63, no. 5, pp. 2702–2712, May 2016.