After water from the south reaches Beijing Tuancheng Lake, some of the water is used to supply the population in the surrounding area, and the surplus is transferred by the Jingmi feeder canal over 100 km to the Miyun reservoir for storage. Due to the elevation of the reservoir, the surplus water from the south must be pumped several meters upward through a set of nine pump stations.
Compared with the sluice gate control on the main canal, monitoring the pump stations for the Miyun reservoir storage regulation project is more complicated. “Water quality information must be quickly collected at critical control points for water transfer and transmitted in real time,” explains Hao. “This is required to carry out engineering safety monitoring of osmotic pressure, earth pressure, joint metering, and the underground water level.”
To enable this monitoring, Hefei Sanli implemented 60 Simatic PCS 7 AS 410 controllers. Profibus and Profinet were also integrated for communication, which is necessary for monitoring various process variables. Thanks to the high-performance Simatic PCS 7 AS 410 control systems, the status point data are collected in less than one second and transferred to the remote database in less than two seconds. Additionally, the CPU module has a mean time between failures (MTBF) of over 100,000 hours, guaranteeing availability of more than 99%.
For monitoring critical facilities such as gate stations, redundancy is a major challenge. The Simatic PCS 7 AS 410 helps ensure reliable data transmission with its paralleled hot standby function and redundant Profibus structure in which racks, power supply modules, CPU modules, and synchronous modules all have the same configuration. If one segment of the network is down, the communication can be rerouted through the remaining functional network sections.