The combined heat and power(CHP)units are operating in the mode of power determined by heat during the heating seasons in the “Three North” areas of China

which forms power and heat coupling operation constraints. This makes the system peak regulation capacity insufficient

which results in heavy wind power curtailment. A method is proposed which can decouple the power and heat operation constraint of CHP units based on heat storage of district heating network and buildings. The technical feasibility of the proposed method is analyzed by the estimation of the potential to enhance wind power integration and the comparison of the investment for several existing methods

and the technical implementation is given by constructing CHP dispatch model. The effects of power output and deep peak regulation ancillary service cost of each main entity are analyzed by applying the proposed method

with summarization and abstraction of the operation rules for the deep peak regulation ancillary service market

in the background of the pilot reform for the Northeast China peak regulation ancillary service market. Furthermore

the individual benefit of each main entity and overall benefits of the system by applying the proposed method are elaborated. The analysis above is verified by simulation cases

and the results show that CHP units are willing to actively participate in system peak regulation by utilizing the proposed method at the individual level

and optimal allocation of the scarce peak regulation resources can be realized at the overall level.