ENERGY DELIVERY SYSTEMS
Project Proposal
IMPROVING THE FUNCTIONING OF A MICROGRID USING A VOLTAGE SOURCE CONVERTER
Renewable Energy sources like solar are the future to fulfilling the growing demands of electricity in the world while not further degrading the environment by using the conventional sources for power generation. Thus, there is an urgent need to utilize such sources of power generation. One of the major problems which crop up while discussing electricity generation via solar energy etc. is the distribution system and also connecting the harnessed renewable energy to the power network. The problem with renewable energy generation is that it requires a completely different design philosophy from the conventional, non-renewable sources when it comes to connecting the generation with the electrical power network. Moreover, another problem which arises with renewable source is that of locating the site. The site for non-renewable sources can be located at various locations but for a renewable source it has to be located near to the resource.
‘A micro-grid consists of bundled renewable micro sources and loads connected together by fast acting power electronics’. (Weerakoon, et al., 2008) . A micro-grid can work independently or in synchronization with the main grid as a discrete energy source. Here, we would be trying to understand the use of micro-grids in incorporating renewable energy generation into the distribution system. In a power transmission network it is very important to ensure accurate flow of active and reactive power sources. This is achieved using voltage source convertors. A voltage source convertor is basically a High Voltage Direct Current (HVDC) convertor which utilizes an insulated-gate bipolar transistor (IGBT).
This objective of the project is to tell how a micro-grid, along with the active and reactive power control can perform the current balancing control.
Technique Used In Compensation of Imbalance Current
The imbalance current should be controlled by the source closer to the unbalanced load. In this way the flow of unbalanced current is completely eradicated from the network. The phase imbalance can be corrected using an energy storage unit which will also be monitoring the currents flowing between the network and the micro-grid, being utilized for other functions. The Voltage Source Convertor to be utilized can be the inexpensive Graetz bridge convertor.
Possible simulation technique
One of the possible simulations for achieving control of the current balance is EMTDC/PSCAD simulations. The designed controllers using VSC and energy storage unit are implemented in the mentioned packages. These simulations would help in calculating unbalanced currents, generating voltage space vector for VSC etc.