Nonlinear head-sensitive hydroelectric generation scheduling in competitive electricity market

This paper presents an effective method for solving the nonlinear head-sensitive hydroelectric generation scheduling in competitive electricity market. The algorithm used is developed for solving a class of constrained dynamic optimization problems. First the powerhouse input-output characteristics of hydro power plants are achieved offline. This problem is formulated and solved using mixed-integer linear programming that takes into account both the non-linearity characteristic and the head loss effect. Second the hourly scheduling is solved in order to maximize the hydroelectric power plant profit from selling energy in the spot market or by means of bilateral contracts. This problem, due the nonlinear characteristics of the objective function, is formulated and solved using dynamic programming within mixed-integer programming techniques. The method is applied to a real hydro power plant of the Portuguese utility. Results demonstrate the efficiency and optimality of our method for this application. Also, some operational strategies, according to the objective function nonlinearity, are pointed out.