ABSTRACT
A
new hybrid control technique called gradient descent back propagation
(GDBP)-based i cos ϕ for a three phase two level distribution
static compensator (DSTATCOM) to perform the functions such as harmonic
mitigation, power factor correction under reactive loads, which further reduces
the DC link voltage across the self-supported capacitor of voltage source converter
(VSC). The weighted value of fundamental active and reactive components of load
currents are extracted using the proposed control technique to generate the
reference source currents. Furthermore, these currents are used to trigger the
VSC of the DSTATCOM. The effectiveness of this control technique is demonstrated
through simulation using MATLAB/SIMULINK and sim power system tool boxes. The
real-time implementation of DSTATCOM is also realised by real-time digital
simulator. These results reveal the robustness of the proposed DSTATCOM as it
is showing outstanding harmonic compensation capabilities under the various
loading conditions and keeping the total harmonics distortion of the source current
well <5%, the limit imposed by IEEE-519 standard.
SOFTWARE: MATLAB/SIMULINK
BLOCK
DIAGRAM:
Fig. 1 Complete layout of the proposed DSTATCOM with
control algorithm
(i) Schematic diagram of the power distribution system including
proposed DSTATCOM
EXPECTED SIMULATION RESULTS:
Fig. 2 MATLAB results for (i) System
performance using i cos ϕ control technique-based DSTATCOM, (ii) Harmonic
spectra of source current, (iii)
Harmonic spectra of load current
and, (iv) Waveform of a-phase source voltage and source current
Fig. 3 MATLAB results for (i)System performance using i cos ϕ control
technique-based DSTATCOM under unbalanced condition, (ii) Harmonic
spectra of source current, (iii)
Harmonic spectra of load current
and, (iv) Waveform of a-phase source voltage and source current
Fig. 4 MATLAB results for (i) System
performance by GDBP controlled i cos ϕ-based
DSTATCOM, (ii) Harmonic spectra of source current, (iii) Harmonic
spectra of load current and (iv)
Waveform of a-phase source voltage
and source current
Fig. 5 MATLAB results for (i) System
performance by GDBP controlled i cos ϕ-based DSTATCOM
under unbalanced loading condition, (ii) Harmonic spectra of source current, (iii) Harmonic
spectra of load current and, (iv)
Waveform of a-phase source voltage
and source current
Fig. 6 MATLAB results for (i) Comparison
of vdc under balanced condition and, (ii) Comparison
of vdc under unbalanced condition
CONCLUSION
The DSTATCOM using GDBP-based i cos ϕ control technique is regarded as one
of the suitable challenging solution for the improvement of power quality. It
has performed better for the source current harmonic reduction, power factor
improvement, voltage regulation and load balancing than traditional method. Also
less amount of voltage is required to store the energy across the self-supported
capacitor causing decrease in rating of DSTATCOM. This proposed technique
assures the corrective actions under any source voltage and load conditions.
The simulation results obtained from MATLAB/ SIMULINK .
REFERENCES
[1] Angelo, B.: ‘Handbook on power quality’ (John Wiley & Sons, NJ, USA, 2008)
[2] Dugan, R.C., Mc Granaghan, M.F.,
Beaty, H.W.: ‘Electric
power systems quality’
(McGraw-Hill, New York, NY, USA, 2006, 2nd edn.)
[3] Bollen, M.H.J.: ‘Understanding power quality problems’ (IEEE press, Wiley India Edition,
2011)
[4] Ghosh, A., Ledwich, G.: ‘Power quality enhancement
using custom power devices’
(Springer International Edition, 2009)
[5] Padiyar, K.R.: ‘FACTS controllers in power
transmission and distribution’ (New Age International, New Delhi, India, 2008)
