| A trans-Canadian grid could lead to increased ability to integrate wind energy by increasing capacity, improving reliability, and reducing effects of non-dispatchable generation by integrating renewable energy sources over a wide geographical area. Use of HVDC technology in the trans-Canadian grid would result in lower losses for the long transmission lines required and also would provide other benefits, such as lower right-of-way requirements, high reliability, and fault isolation. However, there are no current installations connecting a tapped connection to an HVDC line; all HVDC lines are operated using two terminals. This thesis proposes two methods of connecting a wind farm to an HVDC line. Techniques using an AC grid based wind farm and a DC grid based wind farm are analyzed based on their efficiency and component requirements, as well as their ability to operate during normal and fault conditions. The advantages and disadvantages of both solutions are compared, and while the best overall efficiency can be obtained using an AC system, high efficiencies can also be obtained for the DC system when combined with wind turbines with a MV output voltage. Preliminary simulation analysis shows that the DC grid design provides superior isolation of the HVDC line from faults on the wind farm grid, but both the AC and DC grids have potential issues implementing fault ride through, depending on the location of the fault. |
