Fuel cell voltage monitoring system

Introduction
ECN-Engineering & Services has developed a modular voltage monitoring system. It's primary function is to protect the individual cell voltages of fuel cell systems. The VMS is a modular concept: VMS- modules can be connected in series as long as the total DC voltage is below 500 Volt DC. Each VMS module contains 40 analog inputs. The module can operate stand alone or as part of a control system, controlled via a CAN-interface.

1/2 19 inch rack containing 5 VMS-boards

Specification's VMS-board:

• Maximum common mode voltage range per VMS module +150 Volt DC
• Maximum common mode voltage range total VMS system is 500 Volt DC
• Sample rate for all cells: 2 samples per second
• Input channel voltage range 0..- 5.0 Volt DC
• Cell voltage resolution: ca 5 milli-Volt
• Absolute accuracy: < 15 milli-Volt (measured at a common mode voltage of 40 Volt), if reference (signal ground) connected in the middle of the stack, <10 milli-Volt can be guaranteed
• Galvanic isolated CAN transceiver(>500 Volt DC)
• CAN-interface maximum baud rate 500kBaud
• Galvanic isolated RS232 serial port(>500 Volt DC)
• Common mode rejection (60 dB at 100KHz)
• Power supply: 24 Volt DC (isolation between input/output > 1500 Volt), power consumption typical 4 watt
• 2 solid state output contacts: programmable for "warning" alarm and "fatal" alarm
• Cell voltage connector at the front: 50 pole high density 'D' connector
• The boards contain a 8051 compatible microprocessor which is programmable and can be adapted to fulfill custom-specific functionality
• Operational temperature range: 0- 50 Gr. Celsius (-20 to +70 on request)

Euro size VMS board

Contact: Klaas Berkhof (+31 22 456 4225)