Autotransformer 1 AT Line 1 with quadrature regulation transformer 1 TPR Line 1 after replacement was commissioned at substation 750kV “Dniprovska”. The substation started to operate at its full capacity again. This will ensure stable energy supply to consumers of Dniprovskyi region and power output of Zaporizhzhya and South-Ukraine NPP in accordance with safety and reliability requirements.
As prescribed by the Power Plants Technical Operation Rules, an autotransformer after repair must operate fail-safe more than 72 hours. Since this test had been passed, the autotransformer was successfully commissioned.
“There was a necessity to replace equipment due to the damaged quadrature regulation transformer,” noted Oleksii Brekht, Deputy CEO and Chief Operational Officer. “The works to replace the equipment were performed by the employees of Dniprovska and Pivdenno-Zakhidna power systems within the unprecedentedly short period: 17 days. This was caused by the regime factors and conditions for ensuring reliable electricity supply to consumers of the integrated power system of Ukraine. Substation 750 kV “Dniprovska” constitutes a key element of the grid system connection 750 kV, so its stable and reliable operation is crucially important for Dniprovska power system in particular and the integrated power system of the state in whole,” – he stressed.
Moreover, to ensure the compatibility of new lines of the autotransformer and the quadrature regulation transformer with the current conditions of equipment configuration during the replacement, a current lead 15.75 kV was modified. Commissioning of new equipment together with modernization of the current lead 15.75 kV is an extremely responsible task. In particular, the support of the current lead coats with continuing screens should be isolated from structural metal sections using special knots, while the grounding of coats is performed only at one point. The accomplishment of the set task became possible thanks to the team work, high level of professionalism, experience and dedication of our employees.” Oleksand Postryhan, the head of substation 750 kV “Dniprovska,” commented on the event.
More than 80 specialists of Dnipropetrovsk regional operation center and personnel of Pivdenno-Zakhidna power system were involved in the project.
Voltage quadrature regulation is used to redistribute capacity flows between parallel power transmission lines 750 kV and 330 kV operating with a common electric connection via an autotransformer. The purpose of capacity flows redistribution is to optimize working regimes of a power grid and manage its load.
A current lead is an electric technical device used to transmit and distribute electricity. It consists of conductors insulated from grounded parts with solid dielectric materials, protection coats, branch devices, as well as supporting structures. A trunk current lead operates with the current range of 800-5000 A and is used to connect distribution current leads, power distributions points, panels and separate capacities of consumers. The application of current leads in electric grids allows creating safe and multipurpose electric grids, the form of which may be changed depending on the change in production technological processes.