Gundars Ašmanis

Measuring Capacitor Parameters Using Vector Network Analyzers

Vector network analyzer (VNA) is versatile measuring equipment which is primarily used for two-port device S parameters measurements. This paper addresses measurement of capacitor parameters using VNA in broad frequency range. The main attention is focused on the measurement accuracy of capacitors parameters using VNA and proper de-embedding of an experimental setup parasitics to get accurate results. Comparative measurement error analysis for different measurement techniques is presented. Suitability of each measurement technique for measurements of capacitor parameters using VNA is discussed and effect of the experimental setup parasitics on the measurement results is addressed. Moreover useful procedures for proper capacitor impedance measurement using VNA are developed.

Analysis of high frequency effects in three phase EMI filters

In this paper, the three phase EMI filter, characterized by S-parameters to extract mutual couplings, is first time analyzed to evaluate mutual coupling impact on filter insertion loss. The most important mutual couplings that distort insertion loss of three phase filter are discovered and analyzed.

Mutual couplings between EMI filter components

This paper deals with modeling of mutual couplings between passive EMI filter components: inductors and capacitors positioned on printed circuit board. 3D electromagnetic software CST MWS is used for the modeling. Three scenarios are considered: mutual couplings between two capacitors, mutual couplings between two inductors and mutual couplings between inductor and capacitor. Modeling results are verified experimentally using a vector network analyzer. Comparison of the measurement and modeling results shows that transfer coefficients and mutual inductance between two capacitors can be predicted accurately. However modeling of the mutual couplings between two inductors has the lowest accuracy.

Modeling of mutual coupling between inductors

This paper is devoted to EMI filter inductor modeling and mutual coupling modeling between two inductors positioned on PCB. 3D inductor models are developed and modeled in CST MWS. Comparison of inductors mutual coupling measurement and modeling results show that transfer coefficients can be predicted accurately. CST MWS has been used also to predict effective mutual coupling reduction techniques.

Differential mode Il-type EMI filter modeling using CST MWS

This paper deals with modeling of differential mode Il-type EMI power filter using 3D electromagnetic field modeling software CST MWS. Two scenarios are considered: inductor is positioned in parallel or perpendicular to capacitors. Capacitor distance and PCB track layout is changed to verify software modeling precision and capabilities. Measurement and modeling results are in good agreement.

Matrix frequency converter conducted and radiated emissions

Matrix converter inherently exhibits sinusoidal input current waveforms and has less stressful output voltage waveforms, but it is causing problems with conducted and radiated emissions. This paper deals with matrix converter emitted disturbances from point of view of electromagnetic compatibility (EMC) standard EN61800-3 and allocates the sources of undesirable emissions.

LED lighting equipment electromagnetic compatibility

The Electromagnetic Compatibility (EMC) means the ability of equipment to function satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbances to other equipment in that environment. There are different methods how to check if given electrical device complies with specific emission or immunity standards. This work is focused only on radiated emissions because that is one of the hardest tests to pass when we are talking about EMC. Standard EN 55015 shows limits and methods of measurement of radio disturbance characteristics of electrical lighting and similar equipment. In this work we tested six different LED lighting devices (from LED panels to LED light bulbs) with four radiated emission measurement methods: with log-periodic antenna in Semi-anechoic chamber (SAC) — primary method; using Coupling / Decoupling Network (CDN); with biconical antenna in Riga Technical University (RTU) hallway; with monopole antenna in enterprise SIA MassPortal custom made chamber.

Troubleshooting of Matrix Frequency Converter Conducted and Radiated Emissions

Troubleshooting of Matrix Frequency Converter Conducted and Radiated Emissions Matrix converter inherently exhibits sinusoidal input current waveforms and has less stressful output voltage waveforms, but it is causing problems with conducted and radiated emissions. This paper deals with matrix converter emitted disturbances from point of view of electromagnetic compatibility (EMC) standard EN61800-3 and allocates the sources of undesirable emissions using standard equipment used for EMC assessment according to variety international EMC standards and discusses methodology of troubleshooting flow, using low cost equipment available in almost every laboratory of Industrial Electronics and Electrical Engineering.