Page 403 - Renewable Energy Devices and System with Simulations in MATLAB and ANSYS

390 Renewable Energy Devices and Systems with Simulations in MATLAB and ANSYS ®
®

Grid Load

v l
i l
Gas engine

– v b +
Battery SSB
PV

i s
SSB

Fuel cell
H 2
O 2

FIGURE 14.38 Test case of short-circuit fault protection.

14.6 SUMMARY

In order to improve the power of microgrid, a microgrid using a high-surety Super UPS concept is
proposed. Two independent infrastructures, the utility and gas engine, are introduced in the Super
UPS. Renewable energy PV and FC are integrated into the system as well. And the reliability of
the microgrid improves obviously with multiple energies, multiple storages, and the highly reli-
able power conversion system.
According to the architecture deduction and comparison of reliability, cost and efficiency, the DC
bus–centered architecture with redundant inverters is selected for the Super UPS as the best choice.
The highly reliable power management strategies are presented to extend the lifetime of components
and improve the system reliability further. Then a fast isolation solid-state DC circuit breaker with
low-voltage stress is designed based on short-circuit fault current analysis. Finally, the demonstra-
tion and partial experimental results are introduced to verify the system design.

ACKNOWLEDGMENT
This work was supported by the National High Technology Research and Development Program of
China 863 Program (2012AA053602, 2012AA053603) and the Key Project of the National Natural
Science Foundation of China (51337009).

REFERENCES
1. Lasseter, R.H., Paigi, P., Microgrid: A conceptual solution, Power Electronics Specialists Conference,
2004 (PESC 04), Vol. 6, pp. 4285–4290, Aachen, Germany, June 2004.
2. Zhao, B., Song, Q., Liu, W., Xiao, Y., Next-generation multi-functional modular intelligent UPS system
for smart grid, IEEE Transactions on Industrial Electronics, 60(9), 3602–3618, September 2013.
3. Graditi, G., Apicella, A., Augugliaro, A., Dusonchet, L., Favuzza, S., Riva Sanseverino, E., Technical
and economical aspects on integrated PV-UPS systems, 19th European Photovoltaic Solar Energy
Conference, pp. 2572–2575, Paris, France, June 2004.