Device Modeling for Nonstationary Conducted Emissions Based on Frequency- and Time-Domain Measurements

Abstract

In this paper, a new circuit model and measurement methodology for the characterization of electric and electronic devices emitting nonstationary (as well as stationary) conducted emissions (CEs) are presented. The new circuit model combines a frequency-domain characterization of the passive behavior of a device, obtained from its S-parameter measurements, with a characterization of the CE sources obtained from time-domain measurements. It overcomes limitations of previous works providing a robust, efficient, and mathematically accurate description of the interference generation process, in particular in the nonstationary case. The validity and utility of this methodology are assessed by comparing its predictions with measurements performed according to standard procedures. Finally, it is shown how it can be effectively used in the computer-aided design of power-line filters for devices emitting nonstationary CE

Power Quality and Electromagnetic Compatibility Aspects at Personal Computers

“…The CEs yielded by laptop through the power mains cable were detected using LISN and were fed to the EMI receiver [29]. When testing a device for compliance with the FCC and CISPR 22 regulatory limits, a LISN must be inserted between the AC power cord of the EUT and the commercial power outlet [29,30]. Due to the difference (FCC vs. CISPR 22) relative to the regulated frequency ranges, even if the LISNs for both of them have The CEs yielded by laptop through the power mains cable were detected using LISN and were fed to the EMI receiver [29].…”

“…Due to the difference (FCC vs. CISPR 22) relative to the regulated frequency ranges, even if the LISNs for both of them have The CEs yielded by laptop through the power mains cable were detected using LISN and were fed to the EMI receiver [29]. When testing a device for compliance with the FCC and CISPR 22 regulatory limits, a LISN must be inserted between the AC power cord of the EUT and the commercial power outlet [29,30]. Due to the difference (FCC vs. CISPR 22) relative to the regulated frequency ranges, even if the LISNs for both of them have similar layouts, different values are mentioned for their components [31,32].…”

Electromagnetic interference prediction in an in-house power-line network

“…However, an analysis of the CE from a modal point of view, that is, considering the CM and DM propagation instead, is more adequate to understand the propagation phenomena. In order to obtain a modal characterization, an equivalent Sparameter matrix that relates CM and DM waves can be used, commonly called mixed or modal S -parameter matrix ([S M ]) [12], [13]. The modal S -parameter matrix of a twoport network, as seen in Fig.…”

“…I CMX , I DMX , V CMX and V DMX (X = 1, 2, 3) are the modal quantities instead. The modal model of this circuit can be derived using the relationship between the circuit and the modal currents and voltages as [12], [13] By analyzing the circuit of Fig. 3, the relation between the circuit voltages is…”

“…In this paper, the modal analysis is exploited to analyze not only the propagation of the CM, DM and the modal conversion between CM and DM (produced by asymmetries in complex PLN structures), but also the modal behavior of power devices and terminal loads. Power devices such as thermal-magnetic circuit breakers (TMCBs), residual-current circuit breakers (RCCBs), wires or electric devices, are completely and rigorously modeled using their modal S parameters, which relates CM and DM waves [12], [13]. The equivalent modal circuit of parallel branch-line connections has also been derived to implement and simulate a synthetic in-house PLN.…”