Investigation of the reliability of the IPS of South in connection with the acquisition of new concentrated loads (part 1)

Abstract

The paper considers the matters of operational reliability of 500 – 220 kV trunk networks of the IPS of South and the impact of connection of new loads. As is shown in part 1 of the paper, at present the operating trunk networks have had the reliability level (the probability of failsafe operation) at 0.980, which corresponds to the duration of emergency conditions of networks at 175 hrs per annum. With the connection of new consumers the load on 500 – 330 kV trunk networks has increased significantly, which has sharply reduced their throughput capacity margin and lowered their operational reliability, particularly at periods of scheduled maintenance work on 500 kV networks. The transfer electric energy and power from the IJS of the South in additional new energy system on existing backbone networks in the range of 800 – 850 MW, especially in the summer (during the maintenance campaigns) significantly reduces their operational reliability considerably to the failsafe operation probability of 0.965. This extends the probable duration of emergency conditions of network up to 30 – 310 hrs a year and may become a source of systemic emergencies, especially in operating modes with scheduled repair of the main 500 kV power transmission lines that would predetermine a decline in the throughput capacity of the network. Loading the 500 – 330 – 220 kV trunk networks to levels close to the limit values in pre-emergency normal operating modes creates additional adverse conditions for their operation, as in these cases emergency shutdowns of even low criticality power transmission lines could stimulate development of systemic emergencies.