Abstract: In the first startup of the unit No.1 of the Anhui Huadian Suzhou Power Generation Corporation Limited, due to the operators had not sufficient experiences about the plasma oilfree ignition, the amplitude of the adjustment was overlarge, which leaded the variation of the parameters of the main steam was overlarge, and further caused the low pressure differential expansion to be larger and to cause tripping. The reasons of the tripping were analyzed; the adjustment method was improved, so the turbine rolling in the second startup of the unit was successful.

Key words: plasma ignition, oil-free start-up, turbine rolling, low pressure differential expansion, trip