TABLE OF CONTENTS An embedded generator is connected, by definition, to an electrical distribution network. This network is the conduit through which it exports the electrical energy that it produces. Since these exports can have a significant effect on the pattern of flows in the network, it is important to check that they will not degrade the quality of supply for the other users of the network. In most cases, this network was not designed for the sole use of the generator. It may indeed have been delivering power to consumers for many years before the embedded generator was commissioned. If the rating of this generator is a significant fraction of the capacity of the network, it will have a marked effect on the performance of this network. Reciprocally, this network can severely restrict the generator's ability to export power. An embedded generator must therefore be analysed as a component of a system. Its proponents and the owners of the distribution network must perform system studies to ascertain whether the network will need to be reinforced to accommodate the embedded generator. In some cases, these system studies may show that, rather than reinforcing the network, it may be more cost-effective to place limits or restrictions on the operation of the generator.
This chapter will first review the purposes of power flow computations, fault level calculations, stability studies and electromagnetic transient analysis. Then, the principles behind each of these types of studies will be explained. Examples of applications to realistic embedded generation...
