Executive Summary : | Together with other technological advancements, power electronics is being seriously considered as one of the advantageous technologies that could empower future smart grids. Specifically, high power converter, named solid-state transformer (SST) (also known as power electronic transformer or intelligent universal transformer), has caught much attention and been extensively investigated for the distribution systems, but without any real penetration into power system. The basic idea of SST is to achieve the voltage transformation by medium to high-frequency transformer, therefore to potentially reduce the volume and weight as compared with the traditional power transformer. It can also be observed from the configurations of the SST that some other potential functions, which are not present in traditional transformer, can easily be added. It brings promising advantages such as power flow control, voltage sag compensation, fault current limitation, harmonic current elimination, connection of AC/DC loads, which are not possible in conventional transformer. The voltage source converters connected from the secondary terminal of SST can support a regulated dc bus, which could be connected to dc microgrids enabling new microgrid architecture. The SST is essentially a high-voltage and high-power electronic circuit for which the design and reliable operation are major challenges. SSTs at the present time are limited by voltage and power rating of the power devices and available circuit topologies, and as such have not penetrated into the distribution systems. Hence, this project aims the design of gate drivers for such high voltage, high frequency and high power devices for SST applications. The distribution system for long time has been facing the challenge of large space requirements for substation equipment. The power transformer forming the major component of substation equipment needs to be replaced with compact and smaller one without reducing its power rating. This technology will bring transformational change into the distribution system, solving one of the major problems of space crunch in cities.
The SST technology will bring many advantages such as 1) reduced size and weight of transformer (less than 50%), 2) ease of transportation for remote locations, 3) direct integration of renewable sources, 4) Power quality improvement, 5) technology for smart grid. |
