Application of the Model From CISPR 16-4-4 for the Derivation of Limits for Power Drive Systems

Electrical equipment needs to meet disturbance limits to ensure the protection of radio services. In most cases, generic limits are applied which are related to the type of location where equipment is intended to be used. However, in some cases those limits are deemed not to be appropriate, partly because of economic boundary conditions associated with measures to mitigate disturbances, partly because they are used at locations or under conditions with a lower risk of interfering with radio services. Hence, modified limits might be a choice to consider the constraints of equipment on one hand, and nevertheless to reduce the minimum of interference to radio services on the other hand. A procedure how to derive such modified limits is given in the document CISPR TR 16-4-4 in which a probabilistic approach is used. This paper describes these aspects of the approach which are relevant for a particular category of power drive systems and proposes some probability factors which can be used as input for the deriving of radiated disturbance limits in the frequency range from 30 MHz to 1 GHz.