| dc.description.abstract | In recent years, there has been lots of emphasis put on the development of renewable
energy. While considerable improvement on renewable energy has been made,
there are some inherent limitations for these renewable energies. For example, for
solar and wind power, there is an intermittent nature. For the fuel cell, the dynamics
of electro-chemical reaction is quite slow compared to the electric load. This will
not be acceptable for modern electric application, which requires constant voltage of
constant frequency.
This work proposed and evaluated a new power circuit that can deal with the
problem of the intermittent nature and slow response of the renewable energy.
The proposed circuit integrates different renewable energy sources as well as
energy storage. By integrating renewable energy sources with statistical tendency to
compensate each other, the effect of the intermittent nature can be greatly reduced.
This integration will increase the reliability and utilization of the overall system.
Moreover, the integration of energy storage solves the problem of the slow response
of renewable energy. It can provide the extra energy required by load or absorb the
excessive energy provided by the energy sources, greatly improving the dynamics of
overall system.
To better understand the proposed circuit, "Dual Active Bridge" and "Triple
Active Bridge" were reviewed first. The operation principles and the modeling were presented. Analysis and design of the overall system were discussed. Controller
design and stability issues were investigated. Furthermore, the function of the central
controller was explained. In the end, different simulations were made and discussed.
Results from the simulations showed that the proposed multi-port DC-DC power
converter had satisfactory performance under different scenarios encountered in practical
renewable energy application. The proposed circuit is an effective solution to the
problem due to the intermittent nature and slow response of the renewable energy. | en |
