Abstract
The scientific article presents alternative resource-saving protections developed for various electrical installations. The creation of resource-saving relay protection devices for electrical installations against short circuits without the use of metal-intensive current transformers (CT) with metal cores began in the 1960s and remains relevant to this day. The scientific novelty of the work lies in the further development of the theory of constructing protections on magnetically controlled contacts and inductive coils, based on measuring the values of magnetic field induction in protected electrical installations and increasing the reliability of thyristor voltage converters by comparing the volt-ampere characteristics of linear and nonlinear resistors. It is shown that the induction values are sufficient to detect interphase short circuits in electrical installations. In such protection devices, the magnetically controlled contact and the inductive coil simultaneously act as a current (voltage) sensor and a measuring protection device, responding to the magnetic field created by currents in the conductive busbars of electrical installations. To detect the magnetic field, the magnetically controlled contact and inductive coil are installed near the conductive busbars, observing the minimum permissible distance. The aim of the study is to develop new resource-saving protection for various electrical installations, which is an alternative to traditional current protection and also increases the reliability of existing electrical installations. This article proposes new design solutions for implementing protection against short circuits and current overload.