Are Inductive Current Transformers Performance Really Affected by Actual Distorted Network Conditions? An Experimental Case Study. The aim of this work is to assess whether actual distorted conditions of the network are really affecting the accuracy of inductive current transformers. The study started from the need to evaluate the accuracy performance of inductive current transformers in offnominal conditions, and to improve the related standards. In fact, standards do not provide a uniform set of distorted waveforms to be applied on inductive or lowpower instrument transformers. Moreover, there is no agreement yet, among the experts, about how to evaluate the uncertainty of the instrument transformer when the operating conditions are different from the rated ones. To this purpose, the authors collected currents from the power network and injected them into two offtheshelf current transformers. Then, their accuracy performances have been evaluated by means of the wellknown composite error index and an approximated version of it. The obtained results show that under realistic nonrated conditions of the network, the tested transformers show a very good behavior considering their nonlinear nature, arising the question in the title. A secondary result is that the use of the composite error should be more and more supported by the standards, considering its effectiveness in the accuracy evaluation of instrument transformers for measuring purposes.

A lowcost online estimator for switchmode power supplies with saturating ferritecore inductors Ferritecore inductors are largely used in switchmode power supplies (SMPSs) and can be fruitfully exploited also when working in partial saturation. Several behavioral models have been recently proposed to represent both inductance and power losses in saturation conditions. In this paper we exploit this kind of models for estimating online relevant features of the SMPS inductor, such as current ripple and power loss, which are difficult to monitor through acquisition of easilymeasurable quantities only. The method works at electrical steadystate, but is able to follow the thermal transients. Models are implemented on a lowcost microcontroller and tests are performed on a boost converter, for different operating conditions.