We have considered influence of surface complex of current noise on the operations of group protection from single-phase closing to the ground in circuit 6-35 kilovolt with isolated neutral terminal of mountain enterprise. We also have analyzed actions of noise operations of protections in different conditions of circuit: in normal state of working, when short circuit and single-phase closing to the ground arise on protectable connection.
It is necessary to use considerably highomed resisters because of there are requirements to restrict over voltage by voltage 6-35 kilovolts with the resistive ground neutral to the same meaning in the networks. It makes usage of traditional protection from ground short circuit based on a current curve principle is inefficacious. Special characteristics of current curve the type RXIDG realized on digital relay are offered to use for these purposes. For these protections valuation of sensibility was done and the fields of using for opposite dependence characteristics in dependence on dimensions of networks was viewed. There is necessity for these devices of protections nonlinear characteristic of current curve under perfect tooling for protection of the networks 6-35 kilovolts considerably highomed ground neutral ground short circuit in the article.
The work is dedicated to the creation of a specialized test bench for the study of microprocessor-based (MB) relay protection and automation (RPA) devices. The information about the electrical circuit diagram and its functional capabilities is given. Research and study of the operation of relay protection and automation devices is supposed to be carried out in two stages. The first stage is carried out on a personal computer using specialized software. The second stage - studies using a specialized test bench containing a physical model of the electrical network and a specific MB RPA device. The test bench allows to simulate various conditions - from normal load to emergency modes. It is possible to test protections against interphase blocking, asymmetrical load modes, ground fault protections, and emergency control schemes. This method allows to clarify theoretical knowledge and develop primary skills of working with such devices.
