Columbia Automation Systems completely upgraded a paper machine drive system, providing system design, hardware, software, project management, and start-up. The original system was comprised of a line shaft and several analog drives. The upgraded system is a fully digital drive system interfaced with other mill systems complete with on-machine operator interfaces and control room human machine interfaces (HMI).
ORIGINAL SYSTEM
Analog drives and DC motors
Sectionalized wet end
Line shaft from dryers to the reel drum
Pushbuttons and potentiometer operator controls
Drive system monitoring with analog meters, pilot lights, and annunciation panels
PROJECT GOALS
The project goals were accomplished over several short shutdowns to allow production goals to be met throughout the project
Remove line shaft and sectionalize the machine.
Upgrade to digital drive system from analog.
Upgrade operator controls from pushbuttons and potentiometers to a networked system of touch screen panels (on the machine) and HMI computers (in the control rooms).
Revise the control scheme to make the couch the master with progressive draw from wet end to dry end.
NEW EQUIPMENT
AC motors and drives for sections previously driven by the line shaft
Common DC Bus supply with regenerative unit for AC drives
Digital front ends on existing analog DC drives
Supervisory control system for the drives
Touch screen panels (one per section) on the machine
HMI computers (wet end control room, dry end control room, drive room)
Dedicated trending computer with high speed real time and historical trends
IMPLEMENTATION
Installed new supervisory controller and upgraded several wet end analog drives to digital. Installed touch screens on wet end. Temporarily hardwired interlocks and analog signals to remaining analog drives.
Installed new AC drive line up for dryers, breaker stack, calendars, and reel. Pre-commissioning was accomplished with motors temporarily placed behind the machine.
Starting at the reel drum and working toward the wet end, the line shaft was systematically broken and a new motor installed and commissioned on short shutdowns. With each new motor and drive, a touch screen was added for operator control.
Concurrent to the installation of new AC motors and drives, the remaining analog DC drives were upgraded with digital front ends. Additional touch panels were installed for operator control. Hardwired signals and interlocks were removed.
Communication interfaces were installed to interlock the drive system with other machine control systems.
