Communications-assisted schemes for distributed generation protection

Integrating generation into the distribution system presents several challenges. Distributed generation (DG) can affect the coordination between reclosers and fuses, compromising fuse-saving schemes and thereby reducing power quality and reliability. Nuisance tripping of distributed generators, either from local protection or from anti-islanding schemes, is also an issue. The use of communications-assisted schemes is well established at the transmission level. However, conventional communications links may not be cost-effective for use at the distribution level. With the advent of spread-spectrum radio, there is an opportunity to improve the performance of DG protection and anti-islanding schemes. Communications links based on wireless technology are much more cost-effective but have characteristics that can differ from conventional channels. This paper illustrates how teleprotection schemes can be designed to suit both the topology of the distribution network and the characteristics of the wireless channel, allowing DG to be integrated without compromising the reliability of the distribution network.