Daria Nemashkalo

Bio: Daria Nemashkalo is an academic researcher from University of Twente. The author has contributed to research in topics: Time domain & Filter (signal processing). The author has an hindex of 2, co-authored 4 publications receiving 6 citations.

Practical Consideration on Power Line Filter Design and Implementation

Abstract: Electromagnetic interference filters have been studied extensively and proven to be a complex subject, with no single easy solution or rule of thumb. Typical filtering solutions for differential mode disturbances originating from a switched mode power supply are investigated in this paper. A simple T-shape filter model is used to derive an insertion loss equation that is dependent on source and load impedance, which allows to predict filter performance in more realistic settings compared to typical 50/50 Ω measurement setups. It concurs with observations made in a case study that changing filter orientation could increase filter performance.

Mode Decomposition in Multichannel Time-Domain Conducted Emission Measurements

Abstract: A conventional conducted emission test provides insufficient information in terms of differential and common mode interferences. Only the normal mode interference can be measured, which complicates the design or optimization process for a power line filter if needed. Moreover, measurements performed with conventional test receivers are time-consuming and only one measurement channel is available. In this paper, a measurement approach for digital mode decomposition is presented using multiple channels simultaneously. Results obtained with the proposed approach are compared with regular active and passive separation networks.

Multi-Channel Time-Domain EMI Evaluation of Dominant Mode Interference for Optimized Filter Design in Three-Phase Systems

Abstract: This paper describes optimal three-phase filter design based on the measured dominant mode of interference. The modes of interference are determined by simultaneously measuring currents and voltages in all phases in time domain, using a multi-channel digitizer. The measured results are evaluated in frequency domain after fast Fourier transform. While usual electromagnetic compatibility measurement equipment is evaluating only one single channel, the described multi-channel technique allows rapid estimation of dominant modes, for stationary loads, but also for cyclo-stationary, transient and nonlinear loads. Using this method, the topology of power line filter for sufficient suppression of a specific mode of interference from commercial of the shelf three-phase power converter is estimated.

Multichannel Time-Domain Measurements for EMI Filter Optimization in All-Electric Aircraft

Abstract: All-electric aircraft present a new electromagnetic environment in which electromagnetic interference filtering is playing an important role. Together with a maximum take-off weight, the critical need exists for the optimized filtering solutions. A conventional conducted emission test provides insufficient information for the filter design and implementation since it evaluates only normal mode interference and only the total noise that is present in the system can be measured. This paper presents the measurement procedure using multichannel time-domain measurements to evaluate differential and common mode interference that propagate towards both sides of the system in the powertrain of all-electric aircraft. By implementing the described technique, the optimal volume, weight, and placement of filters can be found.

Why Not(ch)

Abstract: The paper presents an alternative EMI filtering solution. Drawbacks of low-frequency differential mode filters are discussed and a solution for mitigating given disadvantages is proposed. A need for filter optimization based on a dominant mode of interference and terminating impedances has been addressed, as well as a novel optimization parameter - the applicable frequency band of the filter. Applying a broadband filter to a narrowband interference proved to be an immoderate solution with respect to weight, volume, and price of the filter. On the contrary, the proposed narrowband notch filter, while providing attenuation comparable to a conventional low-pass filter, has significantly smaller weight and volume.

Capacitors Mutual Inductance Modeling and Reduction

Abstract: In this paper modeling of EMI filter capacitors and modeling of mutual couplings between them is presented. The modeling has been done using 3D electromagnetic software CST MWS. Three capacitor models have been proposed and verified experimentally. All proposed models during verification have shown that their performance is high enough to enable PCB mounted capacitor modeling and mutual inductance modeling between capacitors. Additionally several mutual inductance reduction techniques have been proposed, measured and modeled.

Practical Consideration on Power Line Filter Design and Implementation

Abstract: Electromagnetic interference filters have been studied extensively and proven to be a complex subject, with no single easy solution or rule of thumb. Typical filtering solutions for differential mode disturbances originating from a switched mode power supply are investigated in this paper. A simple T-shape filter model is used to derive an insertion loss equation that is dependent on source and load impedance, which allows to predict filter performance in more realistic settings compared to typical 50/50 Ω measurement setups. It concurs with observations made in a case study that changing filter orientation could increase filter performance.

Mode Decomposition in Multichannel Time-Domain Conducted Emission Measurements

Abstract: A conventional conducted emission test provides insufficient information in terms of differential and common mode interferences. Only the normal mode interference can be measured, which complicates the design or optimization process for a power line filter if needed. Moreover, measurements performed with conventional test receivers are time-consuming and only one measurement channel is available. In this paper, a measurement approach for digital mode decomposition is presented using multiple channels simultaneously. Results obtained with the proposed approach are compared with regular active and passive separation networks.

The Changing Electromagnetic Environment Onboard All-Electric Aircraft, an EMC Perspective

Abstract: All-electric aircraft (AEA) is an emerging subject, due to its environmental contributions and economical appeal, thus, such technology is progressing at a fast pace towards commercial applications. The changing electromagnetic environment (EME) which such aircraft will endure, encompass not only current technologies, but will experience new EMI effects, originating from future mobile communication, power conversion, and increase in air-traffic. As a consequence of an operation relying solely on electric and electrical systems (avionics), together with the implementation of a high-power electric powertrain, AEA will experience increased levels of EMI. Therefore, to regulate the EMI changes onboard AEA, current aerospace standards must be assessed in order to identify possible limitations and bottlenecks. This paper presents an insight into the future EME, its EMC issues, and the intricacies towards the implementation of AEA for regional commercial flights.

Multichannel EMI filter performance assessment

Abstract: Electromagnetic interference filters are being characterized in terms of their insertion loss. CISPR 17 provides measurement procedures for assessing normal, common, and differential mode insertion loss. Respectively, this requires three different setups to fully characterize the filter. This paper shows an alternative to the CISPR 17 setup resulting in a time-efficient measurement approach that allows the evaluation of all modes of insertion loss of the filter in a single measurement setup. Furthermore, it is extended to an approximate worst-case measurement, as in CISPR 17. Complimentary, the suggested setup is used to perform insertion loss measurements of a filter including line impedance stabilization networks, to assess the more realistic performance of the filter in the conducted emission test.