Short term hydrothermal scheduling with bilateral transactions via bundle method

This paper presents a dual approach to solve the short term hydrothermal scheduling (STHS) problem for systems under pool–bilateral markets. First of all, the bilateral transactions and the spot market trades are discriminated in the STHS model. Subsequently, the resulting problem is decomposed into one hydro and a set of electrical and thermal subproblems. The subproblems are solved analytically or by a primal-dual interior point method, whereas the dual problem is solved via bundle method. The commitment status of the generating units is considered known and an augmented Lagrangian is used to define the dual problem. Performance indices are used to analyze the potential of chosen combinations of pool and bilateral trades. The performance of the bundle method is compared to that of a conjugate gradient method. Results are presented for two test systems.