Modeling of operating modes of relay protection in electrical networks with insulated neutral

This work aims to study relay protection and automation in insulated neutral networks to identify additional criteria for choosing the type of earthing. To calculate the single-phase earth fault currents as a function of the operating modes of the electrical substation, the 10 kV network of the electrical substation was simulated in the software package. The advantages and disadvantages of centralized and non-centralized protections are shown. The paper presents the sequence of actions necessary for the correct operation of directional zero sequence protection

Destruction of electrical insulating structures of electric motors during various drying techniques

The paper discusses the problem of drying electric motors in a humid environment. The study considers the influence of oven, current, electroosmotic, convective-electroosmotic drying methods on defect formation in electrical insulating materials of electric motors. Thermal oven drying destroys the insulation system of electric motors for an order of magnitude higher than other methods and has a lot of negative consequences. The electroosmotic and convective-electroosmotic drying processes do not have disadvantages of thermal drying methods, or these disadvantages are kept to a minimum. It is shown that electroosmotic and convective-electroosmotic drying result in a uniform distribution of moisture content in the volume of electrical insulating materials. This reduces the likelihood of dangerous stresses and subsequent cracking. Electroosmotic and convective-electroosmotic drying have little effect on defect formation processes in the insulation system of electric motors and, thus, almost do not reduce the service life of electric motors