With the increasingly prominent problem of load fluctuations in high proportion renewable energy grids

improving the fast load response ability of large-scaled thermal power units under full operating conditions has become an urgent need to maintain the safe and stable operation of the power system. Therefore

a rapid load change strategy combined with the high-pressure bypass transformation technology under the flexibility demand of supercritical power units is proposed. Firstly

the high-pressure bypass is added to the high-pressure regenerative system to flexibly change the steam extracted amount from turbine

thus to accelerate the energy supply rate of once-through boiler. Secondly

to adapt to the high ramping rate

a load change scheme is designed with the limitations of main steam pressure

temperature and their change rate that boiler can withstand at sliding-pressure operation mode and the decoupling of load-main steam pressure for unit. Finally

test on a 600 MW coal-fired thermal power unit shows that

the unit can successfully achieve a high load ramping rate of 3%Pe/min under full operating conditions. Moreover

the main steam pressure

position of main steam valve and other parameters are maintained stable. In addition

the load regulation ability of the unit with load ramping rate of 5% Pe/min is verified

confirming the effectiveness of the proposed load rapid regulation strategy.