Hans Bergsma

Bio: Hans Bergsma is an academic researcher from Thales (Netherlands). The author has contributed to research in topics: Electromagnetic interference & Choke. The author has an hindex of 6, co-authored 18 publications receiving 119 citations.

A new behavioural model for performance evaluation of common mode chokes

Abstract: A behavioural model for performance evaluation of a common mode choke (CMC) is proposed: the topology and methods used to model the different properties of the CMC are presented. It combines an accurate model of the complex permeability, of the saturation, of leakage inductances and of parasitic capacitances. Inputs needed from the designer are measured values of currents, voltages and impedance of the actual system, and parameters available in literature and/or from manufacturers for the modelled CMC. The behavioural model is essential in simulation of EMI effects.

Design of an emi output filter for frequency converters

Abstract: A filter has been designed to reduce conducted and radiated emission generated by a frequency converter. The frequency converter, cables and motor were modelled in order to make a good estimation of the radiated emission. A single stage output filter was designed making use of feedthrough apacitors and a nano-crystalline iron particles common mode choke. This choke has a high saturation level, comparable to a conventional iron inductor, and a high permeability, compared to conventional ferrite, i.e. combining the best of both materials. Measurements have shown that such a filter is very effective.

Risk based EMC for complex systems

Abstract: The rule-based approach, i.e. following electromagnetic interference standards, is the basic methodology assumed to result in electromagnetic compatible systems operating properly in their intended environment. For complex systems we need a smarter approach, based on assessing and controlling the electromagnetic risks. This risk-based approach is described, and applied to naval ships.

Shielding effectiveness measurements using a reverberation chamber

Abstract: Shielding effectiveness measurements have been performed using a reverberation chamber. The reverberation chamber methodology as well as the measurement setup is described and some results are given. Samples include glass reinforced plastic panels, aluminum panels with many holes, wire mesh, among others. The reverberation chamber setup gives very repeatable measurement results.

Protection Against Common Mode Currents on Cables Exposed to HIRF or NEMP

Abstract: Above deck, cables on naval ships are exposed to high-intensity radiated fields and nuclear electromagnetic pulse (NEMP) that may cause conducted interference and generate electromagnetic fields that exceed the immunity levels of commercially available equipment above and below deck. Exposed cables, such as open power plugs or lighting cables, are modeled and characterized both as a monopole antenna perpendicular to the deck and as a transmission line, representing a cable close to the deck. The placement of an illuminated cable close to the deck is a good protection measure for long cables at low frequencies, which includes NEMP protection. The coupled pulse from a high-intensity NEMP illumination is not expected to cause damage on electric installations. It is shown that for exposed cable length of maximum 25 cm and not placed in the line of sight of transmitters above 400 MHz, no additional protection measures are needed.

American Society for Testing and Materials

Abstract: The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.

Analysis of CM Volt-Second Influence on CM Inductor Saturation and Design for Input EMI Filters in Three-Phase DC-Fed Motor Drive Systems

Abstract: Common-mode (CM) choke saturation is a practical problem in CM filter applications. It is generally believed that the leakage inductance of CM chokes makes the core saturated. This paper analyzes two new mechanisms for CM choke saturation due to CM voltage, and these mechanisms are verified in experiment. CM choke saturation is particularly important for motor drive systems, which have a high CM voltage and comparably higher stray grounding capacitance. A model is established to describe the relationship between the CM voltage and the volume of the CM magnetic components. According to the analysis, line impedance stabilization networks (LISNs) play an important role in the design of CM magnetic components.

High-Frequency Model of the Coupled Inductors Used in EMI Filters

Abstract: This paper deals with a high-frequency modeling method of the coupled inductors used in electromagnetic interference (EMI) filters. These filters are intended to reduce conducted emissions generated by power static converters towards the power grid. To model the EMI filters, it is necessary to identify the various parameters of the passive elements: inductors and capacitors. Because of their major impact on filter efficiency, these elements must be identified with accuracy. In this study, high-frequency model of common-mode-coupled inductors is proposed. The identification of the model parameters is based on the experimental approach. Simulation results of the proposed model are compared to the experimental data obtained using the specific experimental setup. These results made it possible to validate the EMI filter model and its robustness in a frequency range varying from 9 kHz to 30 MHz. The proposed high-frequency inductor models will be very helpful for design and optimization of EMI filters, since the high-frequency behavior of the filter mainly depends on magnetic materials used and on the geometrical characteristics of winding.

EMC Modeling of Drives for Aircraft Applications: Modeling Process, EMI Filter Optimization, and Technological Choice

Abstract: A new approach for easy and fast modeling of EMI filter in aircraft application is proposed, in order to be used in an optimization process. A modular description in a user friendly environment allows describing the model and taking into account all the technological parameters of the system, i.e., the control strategy, the inverter model (semiconductors, layout, etc.), the filter, the cables, and the ac machine. The frequency model is automatically built from this description, as well as its gradients according to its inputs. In a second step, by using this model, an optimization of the filter values can be carried out, using various algorithms, to reach the smallest volume. This early design methodology can also be used to investigate the impact of some technological choices of the electrical drive (control strategy or cable characteristics for instance) on the filter volume.