M. Habrych

The Actual State and Prospects of a High Power Electron Beam Technology for Metallic and Non-Metallic Compositions Used in Electric Contacts and Electrodes

In the paper the actual state and prospects of applicability of a high power electron beam technology for manufacturing metallic as well as nonmetallic composite materials mostly for electric contacts and electrodes are presented and discussed

Control of the Singular Points Location for Miniature Switches with Magnetically Driven Contacts

This paper presents and discusses usefulness and possibility of control of the singular points location of a driving magnetic field under as structure considerations as well as selection of energizing magnet systems for miniature electromagnetic switches. The sample results of theoretical analysis and experimental testing concern selected reed switches with normally open contacts as well as a developed miniature switch with a metallic ball contact. It must be noted that the switch with the contact performed by means of the metallic tiny ball can be effectively used both as a change-over switch as well as a detector of the energizing magnetic field distribution under designing and assembling of any electromagnetic contact device preferably with an increased degree of integration and miniaturization.

Comparative performance study of the Hall sensor based directional ground fault protection in MV mining network with ineffective earthing

Paper presents and discusses the investigated results of performance of ground fault protections in common use in MV (6kV and 20kV) distribution mining networks with no-effective earthing. They are compared with efficiency of operation of a newly developed Hall sensor based directional ground fault protection. On the basis of the results the appropriate conclusions regarding applicability of the Hall sensor based protection in practice in MV networks are formulated. Streszczenie. W artykule omówiono wyniki badań działania powszechnie stosowanych zabezpieczeń ziemnozwarciowych sieci średniego napięcia w kopalnianych sieciach rozdzielczych 6kV i 20kV z nieskutecznie uziemionym punktem neutralnym. Porównano je z efektywnością działania, w tych samych warunkach, nowoopracowanego kierunkowego zabezpieczenia hallotronowego. Sformułowano odpowiednie wnioski i zalecenia praktyczne odnośnie do możliwości wykorzystania tego typu zabezpieczenia w praktyce. (Badania porównawcze efektywności pracy kierunkowego, ziemnozwarciowego zabezpieczenia hallotronowego, w górniczej sieci średniego napięcia, pracującej z nieskutecznie uziemionym punktem neutralnym).

Applicability of Rogowski coils made in PCB HDI technology in power system protections

The paper discusses the possibility of obtaining the required parameters of Rogowski coils when apply of printed circuit board high density technology. Selected results of investigations are presented and examples of Rogowski coils for use in electrical power system protections are given.