A fuzzy-PID control strategy for water supply system with variable frequency and constant pressure is proposed

according to characters of system such as nonlinearity

randomicity

large inertia and pure lag.The control strategy combines the advantages of good dynamic response of fuzzy control and high regulation precision of PID control.If the error is small

control output will be determined by PID control algorithm.And if the error is large

control output will be determined by fuzzy control algorithm.The simulation experimental results show that this control strategy can solve the problem of unstable water pressure in water supply and well adapt to the variable model parameters of water supply system has broad application prospect in the city secondary water supply system.