Low-carbon economic dispatch of regional electro-thermal coupled system considering dynamic constraints of CHP units

Abstract

The flexibility modification of Combined Heat And Power (CHP) units can enable the units to have fast electric output regulation capability, respond to grid auxiliary frequency regulation, and enhance the operational flexibility of regional electric and thermal coupling systems. Compared with the CHP unit constraint model established by the vertex convex combination method, the CHP dynamic constraint in the form of differential equations established by the mechanism modeling can reflect the unit variable states in real time and facilitate the mastering of the unit operation status. With the objective of optimal dispatch cost of the regional electro-thermal coupled system considering the carbon trading process, a low-carbon economic dispatch model of the regional electro-thermal coupled system considering the CHP dynamic constraint is established. Based on the sequential method framework, the finite element orthogonal configuration method is used to discrete the differential algebraic equations of the simulation layer, and the improved adaptive differential evolution algorithm is used to solve the nonlinear planning problem of the optimization layer. The algorithm verifies that the finite element orthogonal configuration method can obtain more accurate results with fewer discrete points, improve the solution speed, and verify that the CHP unit with fast electric output regulation can effectively improve the low-carbon operation of the system, which is also beneficial to the safe and stable operation of the unit.