Monitoring of railroad wagons is important for logistical processes, but above all for safety. One of the key parameters to be monitored is the temperature of the axle box and the bearings in the bogie. The problem with monitoring these parameters is the harsh environment and lack of power supply. In our research, we present a power supply system for a WSN node monitoring the bogie parameters. Knowing the operating conditions, we built a power supply system using a piezoelectric energy harvester. The harvester consists of three piezoelectric elements placed on a double arm pendulum beam. The circuit was modeled in the Comsol Multiphysics environment and then built and tested in laboratory conditions. After confirming energy efficiency, the system was tested on a freight car bogie during an 8 h trip. At typical car vibration frequencies (4–10 Hz), the system is able to generate 73 uW. Combined with an energy buffer of 1000 mAh (3.7 V), it can power a WSN node (based on the nRF5340 chip) for 13 years of operation.

This paper aims to present new trends in energy-harvesting solutions pertaining to wearable sensors and powering Body Area Network nodes. To begin, we will present the capability of human beings to generate energy. We then examine solutions for converting kinetic and thermal energy from the human body. As part of our review of kinetic converters, we survey the structures and performance of electromagnetic, piezoelectric, and triboelectric systems. Afterward, we discuss thermal energy converters that utilize the heat generated by humans. In the final section, we present systems for converting energy from the electromagnetic waves surrounding a person. A number of these systems are suitable for use as wearables, such as RF harvesters and micro photovoltaic cells.

This article investigates energy harvesting methods designed to capture energy from the alternating magnetic field surrounding a current-carrying conductor. The study focuses on the use of piezoelectric transducers in both monolithic and bimorph configurations. Experimental tests were conducted using vibrating beam structures composed of a single-layer piezoelectric material as well as bimorph piezoelectric composites, both utilizing lead zirconate titanate (PZT) as the active material. The results demonstrate a significant improvement in energy harvesting efficiency when using the bimorph configuration. Specifically, the bimorph-based system generated a peak voltage of 4.26 V and a current of 127.16 μA, resulting in an RMS power output of 272.48 μW. The operating principles, signal conditioning strategies, and structural differences in the evaluated designs are discussed in detail. The outcomes indicate the potential of such systems for powering autonomous sensors in low-power industrial monitoring applications.

This following article presents the concept of a cheap universal capacitive sensor for partial discharge (PD) measurement. The authors checked the effectiveness of the device prototype on a MV air-insulated switchgear. For this purpose, a combination of a widely used Transient Earth Voltage (TEV) sensor and a detector with Junction Field-Effect Transistor (JFET) was used. The paper presents the results of PD measurements with TEV sensors depending on the phase of the supply voltage. The conducted experiment is the basis for developing the functionality of the sensor and further research.

Artykuł opisuje alternatywne metody pomiaru wyładowań niezupełnych w aparaturze średniego napięcia, takie jak optyczne, ultradźwiękowe oraz elektryczne. W części poświęconej systemom optycznym przedstawiono zasady działania czujników opartych na detekcji promieniowania świetlnego towarzyszącego WNZ. Omówiono również zastosowanie pomiarów ultradźwiękowych do rejestrowania emisji akustycznej, a następnie przybliżono techniki elektryczne takie jak TEV, HFCT oraz anteny VHF/UHF. Podkreślono znaczenie wyboru właściwej metody w kontekście czułości, dokładności oraz możliwości zastosowania w różnych warunkach eksploatacyjnych aparatury średniego napięcia.