ABSTRACT:
In this paper a new cascaded nonlinear controller has
been designed and implemented on the packed U-Cell (PUC) seven-level inverter.
Proposed controller has been designed based on a simplified model of PUC
inverter and consists of a voltage controller as outer loop and a current
controller as inner loop. The outer loop regulates the PUC inverter capacitor
voltage as the second DC bus. The inner loop is in charge of controlling the flowing
current which is also used to charge and discharge that capacitor. The main
goal of the whole system is to keep the DC capacitor voltage at a certain level
results in generating a smooth and quasi-sine-wave 7-level voltage waveform at
the output of the inverter with low switching frequency. The proposed
controller performance is verified through experimental tests. Practical results
prove the good dynamic performance of the controller in fixing the PUC
capacitor voltage for various and variable load conditions and yet generating
low harmonic 7-level voltage waveform to deliver power to the loads. Operation
as an uninterruptible power supply (UPS) or AC loads interface for photovoltaic
energy conversion applications is targeted.
KEYWORDS:
1.
Packed U-Cell
2.
Multilevel
Inverter
3.
Voltage
Balancing
4.
Nonlinear
Controller
5.
Renewable
energy conversion
SOFTWARE: MATLAB/SIMULINK
CONCLUSION:
REFERENCES:
[1]
H. Abu-Rub, M. Malinowski, and K. Al-Haddad, Power electronics for renewable
energy systems, transportation and industrial applications: John Wiley
& Sons, 2014.
[2]
J. M. Carrasco, L. G. Franquelo, J. T. Bialasiewicz, E. Galván, R. P. Guisado,
M. A. Prats, et al., "Power-electronic systems for the grid integration
of renewable energy sources: A survey," IEEE Trans. Ind. Electron., vol.
53, no. 4, pp. 1002-1016, 2006.
[3]
M. Mobarrez, M. G. Kashani, G. Chavan, and S. Bhattacharya, "A Novel
Control Approach for Protection of Multi-Terminal VSC based HVDC Transmission
System against DC Faults," in ECCE 2015- Energy Conversion Congress
& Exposition, Canada, 2015, pp. 4208- 4213.
[4]
B. Singh, A. Chandra, and K. Al-Haddad, Power Quality: Problems and
Mitigation Techniques: John Wiley & Sons, 2014.
[5]
B. Singh, K. Al-Haddad, and A. Chandra, "A review of active filters for
power quality improvement," IEEE Trans. Ind. Electron., vol. 46, no.
5, pp. 960-971, 1999.