This paper presents the overall concept of a wideband and cost-effective current sensor. The sensor consists of a paralleled Hall-based current sensor (LEM) and a wideband current transformer (CT). A significant improvement of the band range and the moderate cost of the proposed sensor enable it to be used both to measure the instantaneous value in order to precisely plot the current and to obtain signals for a closed-loop control system of high-frequency power electronic converters. The sensor should be considered as an Augmented LEM Current Sensor (ALCS), which allows it to measure low- and high-frequency current signals. Finally, it allows for the measurement of a bipolar current up to 40 A. The overall cost of the sensor, along with the previously mentioned benefits, is an important feature of the proposed sensor. The present paper presents the analytical concept of the sensor (ALCS), a theoretical approach using simulation analysis, and the experimental results, which clearly demonstrate the wide range of the sensor in dynamic and static measurements.

The article proposes a method of measuring losses in magnetic elements for medium-frequency power electronics, up to 200 kHz. In the method, the measurement of losses is carried out under voltage–current operating conditions of the inductive element similar to practical applications, adjustable in a wide range. A proposed three-source converter (TSC) allows one to generate proper operating conditions for the inductor. The TSC has been simulated and verified under laboratory conditions.

The article proposes a method to measure core losses in magnetic elements for medium-frequency power electronics circuits working in conditions close to those in many real industrial circuits: supplied with square-wave voltage and working in linear magnetic region. The article presents analytical considerations regarding the proposed method. The proposed method allows determining core losses in power inductor with only voltage and current measurement - no additional EMF-measuring winding is needed. The method is based on the inductor model, which allows determining losses in the core, while at the same time enables obtaining a time-domain response consistent with rectangular voltage excitation measurements. The method was tested using the real industrial inductor with a copper litz winding and low-loss core (e.g. nanocrystalline core) at various operating points.

This article presents a method for determining the essential source current in a single-phase, linear ac circuit with periodic, non-sinusoidal voltage and current waveforms. The instantaneous power of the source in the primary circuit is expressed as the product of voltage and current determined using Fourier series. After shifting the source voltage and current waveforms in time and decomposing them into even and odd components, the source active power is decomposed. Essential and detrimental source currents are distinguished, as well as the active powers associated with these currents, i.e. essential and detrimental source active power. The essential source current ensures the delivery of the essential active power to the load. This power is irreversibly converted to another form of power in the load. The remaining components of the source current are detrimental components that degrade the source operating conditions and should be eliminated from the source current. Eliminating detrimental source active power, which is converted into heat in the load, requires supplying active power to a compensator. Formulas are derived to determine the currents and active powers of the source, compensator, and load after compensation. It was found that after compensation the operating conditions of the source improve. An example of calculation of the essential source current and compensator current, as well as the quantities associated with them, is presented.

W pracy przedstawiono koncepcję szerokopasmowego i niskokosztowego czujnika prądu przeznaczonego zwłaszcza do zastosowań w energoelektronice. Prezentowany czujnik składa się z równolegle połączonych czujnika prądu wykorzystującego efekt Halla (typu LEM) oraz przekładnika prądowego. Szerokie pasmo czujnika (poczynając od składowej stałej) i umiarkowany koszt budowy predestynują to urządzenie do wykorzystania zarówno w pomiarach i rejestracji przebiegów prądu, jak i w zamkniętych układach regulacji systemów energoelektronicznych. Wykonano i przetestowano układ doświadczalny pozwalający na pomiar prądów bipolarnych o maksymalnym natężeniu do 40 A. Zaprezentowano podstawy teoretyczne i wyniki prac laboratoryjnych obejmujących badania statyczne i dynamiczne proponowanego czujnika.