Optimization calculation method for main steam pressure of turboset under variable working conditions

The invention provides a turboset main steam pressure optimization calculation method under variable working conditions. The method comprises the following steps: setting a reference working condition, determining power of a generator, and changing main steam pressure; assuming a comprehensive valve position variable quantity, and calculating changed main steam flow, high-pressure cylinder efficiency, effective power of a water feeding pump and new steam extraction pressure; the low-pressure cylinder steam exhaust amount, the heater outlet water temperature, the steam extraction flow of each stage, the main steam heat absorption amount, the reheat steam heat absorption amount and the condenser heat release amount are calculated, and new generator power is obtained; comparing the power of the new generator with the power of the generator under the reference working condition, and judging whether to finish to turn to the next step or not; and the different heat consumption rates obtained through variable workin