This paper reviews some of the major approaches to modeling and simulation in power electronics, and provides references that can serve as a starting point for the extensive literature on the subject. The major focus of the paper is on averaged models of various kinds, but sampled-data models are also introduced. The importance of hierarchical modeling and simulation is emphasized.

Modeling and simulation of power electronic converters

Since the efficiency of switched mode power supplies (SMPS) is much higher than that of linear power supplies, this type of supply has gained favor among designers and manufacturers. Switching frequencies extend from tens to hundreds of kilohertz with the result that radiation from circuits carrying switched current is becoming more of a problem. This paper addresses the modeling of the converter section of an SMPS in order to calculate the current distribution and the radiated electromagnetic field. The inhomogeneities in the circuit are by equivalent electrical parameters and a technique is introduced to take into account the fictitious effects on radiation due to the electrostatic terms in the dipole equations. The global approach is validated by comparison of the computed results with those measured for a simple and clearly arranged SMPS experimental setup.

EMC characterization of SMPS devices: circuit and radiated emissions model

Power conversion systems and in particular power drives are now present in a large number of applications and environments. The switching operations of power drive systems (PDS) are sources of radiated and conducted electromagnetic interferences that give rise to problems of electromagnetic compatibility with other systems. This work proposes an efficient numerical technique to evaluate the radiated emissions due to a PDS, taking into account the radiation from intentional apertures (i.e. those for ventilation). The power section of the PDS is simulated by a combination of radiating dipoles in which the current is known. The radiated EM field induces currents on the PDS metallic cage surface that in turn radiate outside the cage. These currents are computed by an efficient numerical method known as partial element equivalent circuit technique. Finally an equivalent EM model for the apertures needed for the air cooling and ventilation of the device is given. The proposed prediction model is hence able to predict the total radiated emission from a PDS in its design stage in order to fulfil the electromagnetic compatibility requirements called by the international standards.

A prediction model for electromagnetic interferences radiated by an industrial power drive system

Two methods of computation of the electromagnetic fields radiated by power converters are developed. They permit the calculation of the near field from the topographic implantation, which is necessary in order to verify the correct operation of the control unit. Finally, comparisons of measured and computed electromagnetic fields are reported.

Near-field characterisation of power electronics circuits for radiation prediction

With the advent of the wide-bandgap devices, it has become possible to switch at a faster rate (on and off) along with higher switching frequencies. This results in attaining higher power density, smaller filter size, and lighter weight for the power converter. But the bottleneck of taking advantage of these ultra-fast devices is spurious behavior during operation due to cross talk and electromagnetic interference inheriting from higher dv/dt and di/dt. To meet the standard and to ensure robust operation, EMI filter is in place for a time being; mostly to meet conducted emission requirements. To deal with radiation, shielding is a common practice. This work aims to understand how much the EMI filter helps with radiated EMI reduction. A converter with a traditional passive EMI filter is considered to evaluate the effect of the filter on the near magnetic field adjacent to the converter. The observed phenomenon has been analyzed and explained to understand to what extent the conducted EMI filter helps with mitigating radiated emission.

Investigation of Power Converter's Near Field EMI Containment Using Passive Filters

An EMC analysis of a switched mode power supplies (SMPS) is presented which shows the variation of the radiation patterns, near field spatial distributions and radiation properties as the SMPS's load is altered. Depending upon the loading, the SMPS exhibits magnetic or electric dipole behavior. Currents and fields calculated by an accurate prediction model are compared with those measured.

S. Cristina

Papers

Switched mode power supplies EMC analysis: near field modeling and experimental validation