Evaluation of possible variants of backup methods of starting reversible pump-turbine motor-generator sets at the zagorsk pumped-storage station in a pump mode

1. As a rule, a backup starting device differing fundamentally from the primary one is provided for at multiple-set PSSs with high-power reversible sets (single capacity of 100 MW and more) regardless of the type and number of the primary starting devices. 2. The use as a backup method of asynchronous connection of high-power reversible sets to the total line voltage cannot be recommended, since such connection has a negative effect on the stability of the power pool and, furthermore, requires taking special design measures which lead to a considerable increase of cost of the motor-generator with a simultaneous decrease of its reliability. 3. Under conditions of an operating station, when selecting the backup starting method it is necessary to take into account the impossibility of a major rearrangement of the electrical equipment and expansion of its composition. 4. The results of tests at the Zagorsk PSS and calculations at the Moscow Power Institute confirm the prospects of using as a backup theasynchronous-synchronous method of starting from an adjacent reversible set, which provides simplicity and reliability of asynchronous starting and minimum current loads at the stage of synchronous frequency acceleration.