Adding motor and converter to double-turbine regeneration system composed of backpressure extraction steam turbine(BEST) can make the BEST start more flexible. The operation and control measures of the system are introduced

and a series of system tests are carried out under different conditions during the unit commissioning.The results show that

the converter has relatively high accuracy on control of the BEST rotation speed

and the electric/power generation mode can be switched smoothly. Under accident conditions

the switching between the converter control and micro electro-hydraulic control system(MEH) control has the characteristics of rapid and small disturbance

which ensures the safety and stability of the unit operation. The above tests verify the actual controllability

safety

stability and reliability of the converter in the BEST in the feed water system. Through the economic calculation

the unit can save about 2.1 g/(kW·h) of standard coal when running at full load under THA condition

which has certain economic benefits.