In this letter, a hybrid modulation concept
consisting of three-level space vector modulation (3L-SVM) and phase-shifted pulse
width modulation (PS-PWM) is proposed for five-level active neutral- point-clamped
(5L-ANPC) converter. Under this concept, a simpler 3L-SVM plus PS-PWM scheme is
applied to realize 5L modulation, instead of using complex 5L-SVM. The control
of neutral voltage, flying capacitor voltage, and the improved dc voltage utilization
are all implemented. With the help of the proposed concept, well-developed 3L-SVM schemes can be
directly applied to the 5L-ANPC converter, which significantly simplify the
gating signal generation. This concept can also be applied to other hybrid clamped
5L converters with two dc-link capacitors. It provides a unique solution, which
utilize lower level SVM scheme to control higher level multilevel converters.
KEYWORDS:
1.
Five-level
active-neutral-point-clamped (5LANPC)
2.
Multilevel
converter
3.
Phase-shifted
pulse width modulation (PS-PWM)
4.
Space vector
modulation (SVM)
SOFTWARE: MATLAB/SIMULINK
CIRCUIT DIAGRAM:
Fig. 1 Single-phase circuit of a 5L-ANPC
converter.
Fig.
2. Waveforms of modulation wave Vma , phase voltage vphase ,
line–line voltage vl l , three-phase current, two dc-link capacitor
voltage, and three-phase FC voltage of 5L-ANPC converter with proposed hybrid
modulation concept: (a) M = 0.23. (b) M = 1.15.
(c) Neutral voltage and FC voltage control.
Fig.
3. Comparison waveforms of modulation wave Vma , phase voltage vphase ,
line–line voltage vl l , three-phase current, two dc-link capacitor
voltage, and three-phase FC voltage of 5L-ANPC converter with PS-PWM in [5]:
(a) M = 0.23. (b) M = 1.15.
(c) Neutral voltage and FC voltage control.
CONCLUSION:
In
this letter, a new hybrid modulation concept is proposed for 5L-ANPC
converters. Instead of using 5L-SVM, it applies 3L-SVM plus PS-PWM to modulate
the 5L-ANPC converters. With the proposed concept, the control of neutral
voltage, FC voltage, and the increased voltage utilization are all realized. Well-developed 3L-SVM schemes can be applied
directly to simplify the modulation process. The simulation and experiment have
proved the effectiveness of the modulation scheme. Although this modulation
concept is developed for 5L-ANPC converter, it can also be applied to other
hybrid 5L converters with two dc-link capacitors [13]. By dividing these
converters into two cells, 3L-SWM can be applied to their 3L converter cells,
while both cells are together modulated by PS-PWM using the modulation waves
derived from 3L-SVM. The proposed concept provides a unique solution which
utilize lower level SVM scheme to modulation higher level multilevel converters
at desired performance.
REFERENCES:
[1]
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[2]
P. Barbosa, P. Steimer, J. Steinke, M. Winkelnkemper, and N. Celanovic, “Active-neutral-point-clamped
(ANPC) multilevel converter technology,” in Proc. Power Electron. Appl. Eur.
Conf., 2005, pp. 1–10.
[3]
J. Li, Z. Pan, and R. Burgos, “A new control scheme of five-level active NPC
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IEEE Energy Convers. Congr. Expo., 2014, pp. 234–241.
[4]
R. T. Hamid, S. Danny, M. M. Kashem, and C. Phil, “Novel modulation and control strategy for five-level ANPC
converter with unbalanced DC voltage applied to a single-phase grid connected
PV system,” in Proc. IEEE Ind. Appl.
Soc. Annu. Meet., 2013, pp. 1–8.
[5]
K. Wang, L. Xu, Z. Zheng, and Y. Li, “Capacitor voltage balancing of a five-level
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