Sea Floor Cabled Observatory Instrument Power Control and Monitoring----A newly design of generic cabled observatory instrument power health status monitoring and control unit, considerations, implementation and practice

Abstract:

Sea floor cabled observatory is a multidisciplinary research platform, there are variety instruments connecting observatory, whose power consumption vary from a few watts to a few hundreds watts. Those instruments power supply status require to be carefully remotely controlled and monitored. The basic parameters include controlling instrument on and off, monitoring instrument power supply health status such as voltage, current and ground fault etc., those data are critical for both properly instrument operating and data quality control. Ocean networks Canada (ONC) is continuing to extend its NEPTUNE and VENUS observatories and is keeping build new observatories. A compact generic power control and monitoring unit was designed and build to meet those requirements. The unit is small enough (120Lx75Wx15H mm) to fit inside most pressure house. This small unit includes the following functions:

• Power on/off switch
• Voltage and current monitoring
• Over/under voltage automatic protection
• Over current automatic shunt down
• Ground fault monitoring
• Soft start and Inrush current control
• Mechanical relay isolation control for power supply
• External DC/DC convertor temperature monitoring and control interface
• RS422 addressable for units in daisy chain

It had been successfully used for variety projects such as ONC Smart Ocean project, such as neutrino telescope project, regional circulation moorings and smart ocean observatories, more than 20 mini junction boxes had been build based on this design, and controlling close to 200 instruments.