... Fig.1 - Q-H Curve of the Variable Speed Pump In figure 1, a is the Q-H curve of which the pump runs with the rated speed n0, b is the Q-H curve of which the pump runs at the speed of n1, ... obtained by Q-H characteristic curve of the pump, HSi,j,k is the head of kth pump, ηi,j,k is the efficiency of kth pump whose expression can be obtained by the efficiency curve of the pump, ... to solve the optimal operation model of mixed-pump stations with the operating-mode adaptability. The outlet flow ,ijQP of each pump station is taken as the decision variable of the first...