TABLE OF CONTENTS Modern electrical power systems have been developed, over the last 50 years, mainly following the arrangement indicated in Figure 1.1. Large central generators feed electrical power up through generator transformers to a high voltage interconnected transmission network. The transmission system is used to transport the power, sometimes over considerable distances, which is then extracted from the transmission network and passed down through a series of distribution transformers to final circuits for delivery to the customers. However, recently there has been a considerable revival in interest in connecting generation to the distribution network and this has come to be known as embedded or dispersed generation. The term embedded generation comes from the concept of generation embedded in the distribution network while dispersed generation is used to distinguish it from central generation. The two terms can be considered to be synonymous and interchangeable.
Between 1997 and 1999 dispersed generation was investigated by working groups of both CIGRE (The International Conference on Large High Voltage Electric Systems) and CIRED (The International Conference on Electricity Distribution Networks). The two reports of these Working Groups [1,2], which are largely complementary, provide the most comprehensive review available of both the extent and main issues associated with dispersed generation and, together with supporting documents, are reviewed in the first part of this chapter.
There is, at present, no universally agreed definition of what constitutes embedded or dispersed generation and how it differs from conventional or central generation. Some common attributes of embedded...
