A novel micro power generation system to efficiently harvest hydroelectric energy for power supply to water intelligent networks of urban water pipelines

Recently, the spot utilization of surplus pressure in water pipelines to generate and supply energy to intelligent water networks using micro hydropower generation systems has gained significant attention. However, the mechanical seal which is generally adopted in traditional hydropower generators has friction loss and water leakage problems, causing low power generation efficiency and operation stability of generators. In this context, a novel integrated permanent magnet generator (IPMG) which replaces the traditional dynamic mechanical seal with a static seal is proposed. A finite element method based optimization approach is developed to enhance IPMG configurations under multiple design criteria. An IPMG prototype was subsequently manufactured, and its electricity generation performance under different rotation speeds and water velocities was tested. Also, the impacts of different key parameters on the IPMG performance were numerically investigated. The results revealed that the employment of permanent magnet generator helped IPMG to possess superior performance in completely eliminating friction loss and reducing leakage risk. Compared to the traditional generator, the startup water flow velocity of IPMG was effectively reduced so that the total operating hours were significantly extended by 35%. And its annual power generation can be increased by 35.8% for application in urban water supply pipelines.