A soft magnetic MnZn-type ferrite is considered for high frequency applications. First, the morphological, structural, and chemical composition of the material are presented and discussed. Subsequently, by using a vibrating sample magnetometer (VSM), the hysteresis loops are recorded. The open magnetic circuit measurements are corrected by employing demagnetization factors, and by taking into consideration the local magnetic susceptibility. Finally, the hysteresis losses are estimated by the Steinmetz approach, and the results are compared with available commercial information provided by selected MnZn ferrite manufacturers. Such materials are representative in planar inductor and transformer cores due to their typically low losses at high frequency, i.e., up to several MHz, in low-to-medium power applications and providing high efficiency of up to 97%–99%.

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Most of the in-service power distribution transformers from the industrial electric facilities were designed to operate under pure sinusoidal state conditions. Nevertheless, the majority of the loads from modern electric installations are intrinsically nonlinear and consequently, they generate nonsinusoidal currents. These high-order harmonics (present into the current waveform spectrum) have a negative impact on the transformers thermal and electrical operating parameters and, ultimately, limit the machine loading capability. The paper quantitatively investigates the transformer behavior under distorted current conditions by developing a procedure for evaluating different relevant operating quantities (maximum permissible current, the hottest spot temperature, aging acceleration factor and the machine remaining lifetime). The computation relays on the international standard recommendation and mainly uses the load current harmonic spectrum and the transformer rated data. To reveal the proposed procedure performance, a distribution transformer of 400 kVA from an industrial plasterboard facility is investigated.

In modern low-voltage electrical installations, the predictive maintenance of the major electrical equipments involved in the power delivery process (transformers) or in the conversion of the electrical energy (especially electric motors) becomes mandatory. Thus, a high level of reliability and safety is assured for both the electric facility and operators. The proactive maintenance is to be non-invasively performed and mainly requires an infrared (IR) thermographic inspection and power quality analysis of the installation loads. A vibration investigation is also necessary for the motor drive systems. The paper critically studies the first two main maintenance procedures revealing their main characteristics, performances and limits. A case-study presents a 1000 kVA distribution transformer that supplies a bakery facility that comprised mainly heaters and inductions motors as loads.

Nowadays, Failure Mode and Effect Analysis (FMEA) is more present in any standard evaluation of a product or process. In automotive industry, the IEC 61508 Standard adapted the ISO 26262 restrictions for Electrical and Electronic Devices. Conducting an FMEA reduces the costs by focusing on preventing failures, improving safety and increasing customer satisfaction. This paper presents a case study of a FMEA on a CAN (Controller Area Network) Bus Harness considering the entire process from defining the scope and building the team, to the action plan that will reduce the Risk Priority Number below the acceptable risk value. Also, the brainstorming that identifies the possible failure modes is presented.