A practical approach to solving large drive harmonic problems at the design stage

Harmonic problems are a major concern during the early stages of projects that could utilize large variable-frequency drives. An attempt to show how to eliminate the harmonic problems early in the design phase of a project is made. Problems arising from harmonics are discussed. IEEE Standard 519 is suggested as the starting point in the creation of a harmonic specification for the purchase of a complete drive system. A useful reference in determining the actual levels of harmonics that will be permitted is the specifications of other countries. During the initial design and on tendering the drive package, it is necessary to obtain information about the power system and provide this to the drive vendor. Development of the tender package is discussed. Harmonic reduction options are considered. Design check points and field verifications are reviewed