Abstract: Taking the 330 MW extraction and condensing steam turbine generator set of a power plant as the research object, the effects of five retrofit schemes, including low-pressure cylinder cutting, high-pressure and low-pressure bypass modification, adding heat storage tanks, electric boilers and absorption heat pumps, on the safe operation feasibility range and thermoelectric decoupling ability of heating units were calculated and analyzed. The thermodynamic model of the case unit was established by EBSILON, and the energy consumption of each retrofit scheme was simulated and calculated. Results show that the five retrofit schemes can expand the safe operation feasible region of the cogeneration unit, among them, the maximum heating capacity increase of the unit is the largest under the two-stage bypass transformation plan. Except for the low-pressure cylinder cutting retrofit, the thermoelectric decoupling ability has been improved to varying degrees under the other four schemes, with the electric boiler renovation scheme having the strongest thermoelectric decoupling ability when the electric heating load is low. Under the same conditions, the coal consumption of each retrofit scheme from high to low is electric boiler, two-stage bypass, low-pressure cylinder cutting cylinder, heat storage tank and absorption heat pumps.