COMBINING THE ENTIRE COMPLEX OF POWER GRID PROTECTIONS IN A CIRCUIT BREAKER WITH LINEAR AND NONLINEAR LOADS

Circuit breakers in low-voltage power grids are the most common elements of the entire protection system. Therefore, their important quality is autonomy, which is understood as the ability to perform their protective functions when connected only to the power part of the power grid. That is why in most cases, circuit breakers use such protections, for the construction of which information from current sensors is sufficient. Such protections include protection against phase-to-phase and single-phase short-circuit currents and against overload currents. For the implementation of other, more complex types of protection, such as protection against remote short circuits, protection of backup failures of feeder circuit breakers, protection against neutral conductor breaks and the resulting overvoltages, devices that do not meet the requirements are used. This is due to the fact that in order to build these complex protections, information from current sensors alone is not enough – information about the network voltage, power, etc. To do this, it is necessary to develop such methods for building complex protections, for the implementation of which information from current sensors alone is sufficient. At the same time, the necessary reliability of network protection with both linear and nonlinear loads must be maintained. This paper presents methods for constructing the entire complex of protection of power grids with both linear and nonlinear loads in a circuit breaker. To construct the entire complex of protections, information is used only from the current sensors of the circuit breaker