Study And Realization Of The Energy-Efficiency Control Strategies For Variable-Frequency Constant Pressure Multi-Pump Parallel Water-Supply System

In the development course of human society,demand for water-supply is always the core demand of life and production.Multi-pump parallel water-supply system based on variable frequency technique is widely used because of its flexibility.However,the inappropriate control of number and rotational speed in many water-supply system makes the system operate in low efficiency and result in huge energy waste.Therefore,the multipump water supply system still has a lot of optimization space in terms of control strategy.In this thesis,the energy efficiency optimal control strategy of the parallel-pump group is deeply studied and analyzed from the perspective of energy saving optimization.Firstly,for the water-supply system consisting of same water pump operating in parallel,the efficiency model of the pump system is established.To maximize the efficiency of the parallel pumps in operation,the appropriate mathematical analysis is taken and the best-efficiency control strategy meeting different hydraulic demands is put forward.And then,for the water-supply system which is composed of pumps of different types,the precise energy consumption model is established.To minimize the total power consumption of the pump system under the premise of meeting different hydraulic demand,an improved differential evolution algorithm is adopted and the optimal control strategy with the lowest energy consumption is proposed.Finally,based on the proposed optimal control strategy,a multi-pump parallel variable-frequency constant-pressure water-supply system is designed,and its hardware and software implementation is elaborated.In order to verify the optimal energy-efficiency strategies proposed in this thesis,related experiments and simulations were designed.For the pump set consisting of different type pumps,the optimizations of control strategies for different working condition in real system are simulation based on MATLAB.For the pump set consisting of the same type pumps,the experiment platform is designed and the experiment are carried out under different hydraulic.Experiments and simulation results show that the system designed can realize stable and reliable operation.Meanwhile,the results verify the feasibility and stability of the optimal energy-efficiency control strategies proposed and further illustrates the huge potential for energy saving optimization in terms of control strategy and the good application value in the multi-pump parallel variable frequency water supply system.