The article presents the conditions of coordination of adjacent remote protections with remote start-up, considering the peculiarities of parameters, operating modes and operating conditions of partitioned branched distribution lines. The influence of parameters and modes of operation of such lines on the technical characteristics of these protections, in particular, on the range of control settings for resistance and operating time at the end of the range and the requirements for the linearity of time characteristics. It is recommended to use the results of the conducted research for adjustment of remote protections of partitioned lines with sources of distributed generation. In order to ensure the selective action of protection in different modes of operation of the lines and the convenience of choosing the settings of operation, the time characteristic of the protection must be linear. In addition, the linearity of the protection time characteristic allows the operation time value to be used to determine the distance to the short circuit location. Due to the need to debug the protection by the time of operation from the operation of the arresters and from burnout of the fusible insert fuses soldering in the event of a short circuit directly behind the fuse, the initial duration of protection should be 0.25…0.40 s.

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The article investigates the parameters of setting up adjacent remote protections with remote start-up, taking into account the peculiarities of operating modes and operating conditions of partitioned branched distribution lines. The influence of parameters and modes of operation of such lines on the range of adjustment of settings on resistance and time of operation at the end of a zone of action and requirements to linearity of time characteristics that allows to define distances to a place of short circuit on operation time is defined. The results for setting up remote protections of partitioned lines with sources of distributed generation are obtained: the conditions for adjusting the protection settings for resistance to operation are determined taking into account the parameters of the partitioned lines and the limits of adjusting the settings for resistance to secondary values are determined. The conditions for adjusting the settings by the time of operation and the limits of the time of operation of protection for most lines are determined. For selective operation of protection at the selected settings on time of operation unambiguity of time characteristics at change of sizes of working currents of protection on condition of ten percent accuracy of work of protection on resistance of operation is provided. The conditions for ensuring the selective operation of adjacent protections in the selected range of settings by the time of operation, taking into account the ratio of resistances and the difference in the time of operation are determined. The initial time of protection protection is substantiated for debugging of protection on time of operation against operation of overvoltage limiters and against burnout of fusible insert of fuses of branches and unsoldering at short circuit directly behind the fuse. The use of modern microprocessor protection devices will ensure, on the one hand, the accuracy of the resistance, linear and unambiguous dependence of the operating time on the resistance of the short circuit at different levels of currents and voltages, etc., and on the other hand - ease of maintenance.

When powered from a backup source, the short-circuit currents in the protected area are much lower than the current cutoff insert installed at the sectioning point, therefore, in this case, the current cutoff is ineffective. In cases where the maximum current directional protection (MCDP) does not provide the required sensitivity, it is advisable to use distance protection with dependent exposure on sectioned lines and lines from distributed generation sources (DGS) in a significant decrease in voltage on the DGS buses during external short circuits through a relatively large reactance of small and medium power. Different modes of operation of sectioned lines from DGS are characterized by a change in the direction of flow of the load current and short-circuit current. Therefore, on such lines, maximum current directional protections can be applied, which provide selective action of adjacent sets of line protection in different modes of their operation. The use of definite time protection leads to the accumulation of a long time delay for the protection installed on the main switch (especially when several sectioning switches are installed on the line), which complicates the coordination of the protection of the main sections of the lines from the protection of the supply substations. The article deals with the problems of improving relay protection for distribution networks with distributed generation sources (DGS). Paying attention to the peculiarities of protection operation under different operating modes of such networks, namely: normal and post-emergency. The protection of lines from DGS must meet the general requirements for ensuring the necessary sensitivity, selectivity of action for different types of damage. Difficulties in ensuring the required sensitivity when using overcurrent protection and current cutoff in such networks are caused by the low level of short-circuit currents from backup sources. The features of the implementation of relay protection in sectioned networks when they are powered from the DGS are given. The expediency of using remote triggering devices for distance protection to increase the sensitivity of protection of sectioned lines from DGS has been substantiated.

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