Fundamentals on harmonics

Large industrial loads, such as variable speed controllers, call for measures that keep power system disturbances within permissible limits. These limits are based on recommendations and standards established by national and international organizations. In the case of large frequency converters, the major impact on power quality is expressed in terms of power factor and harmonic distortion. The applicable standards are becoming more and more stringent, i.e. setting higher power and lower distortion factors. The impact of these mainly power utility-defined limits on the design of the network and on the correction equipment (e.g. filters) is discussed.