Tae technologies powers up with reliable control system

Editor's Notes

• #6: This is a somewhat simplified explanation of what happens! There are about 50 subsystems on this machine (depending on the configuration) and the Vacuum PLC system is just one of them. We have 20% PLC controlled the remainder is LabVIEW using some National Instruments hardware for acquisition, critical timing and control functions. The Vacuum system using ControlLogix L85 is a good example of how to engineer a very complex system and to use creative programming techniques to simplify a complex problem. The 7 chambers are under an ultra high vacuum system with pressures around the 1E-9 Torr. We accomplish this by using a variety of pumping techniques including cryogenic and Titanium evaporation. The Vacuum PLC is therefore critical in the control and monitoring of a large number of systems to maintain the high quality vacuum and to deal with fault scenarios. A DC magnetic field is created along the vessel. Deuterium gas is injected into the Formation section and a sequence of high current discharges first ionizes the gas and then traps magnetic energy in the plasma creating a football shaped toroid. Both Toroids are propelled towards the center of the machine where they are held captive by Mirror fields. Neutral Beam injectors – basically high energy particle injectors – inject neutral 15keV hydrogen into the vessel where the atoms are ionized and create a circulating current in the Toroid. This current mains the internal magnetic fields and confines the plasma. If the beams terminate then the plasma disappears after a few 100us. So far we have sustained the plasma for 10ms limited by the stored energy on site. The current experiment is operating and had reached its Phase 1 goals. We’re currently operating on initial Phase 2 work in flaring the magnetic field lines into the Inner Divertor Chamber.
• #9: 7 main vessel chambers 8 Neutral Beam chambers Over 20 turbo pumps: 2 turbo on each divertor and central vessel (10) 1 turbo on each Formation and 8 NBI (10) Additional Turbo pumps used for some vacuum facing Diagnostic systems Vacuum control is distributed throughout the machine with about 40 pneumatic and analog input boxes connected via a fiber network to a ring system of 24-port predominately fiber switches. A single L85 controller and Ethernet modules is housed in a rack located in the server room. The Vacuum system has it’s own EtherNet/IP subnet for DIO and a connection onto the main control network for HMI and programming access.
• #10: Photos show the type of Gate Valves we control and monitor as well as Turbo Pumps and smaller angle valves. The Pneumatic system uses and SMC EX600 manifold and we also use their DI blocks to save on space. Gate Valves – Interfaced with pneumatics and DI Turbo pump – interfaced with TD20 Controller and Profibus via EtherNet/IP Gauges are power via 24V DC and interfaced to AI (0-10V)
• #11: Correct network design is critical to reliability. As we use predominately fiber optics to communicate to equipment we selected: N-Tron NT24K rack mount switch with 100FX and 1000SX fiber modules Handles EtherNet/IP without issue (as many manufactures do) Ring system at 1Gb allows for about 60 drops to equipment Pay attention to the number of IGMP groups on the subnet Server room switch interfaces to the Cisco core switches 1G/10G, VMware clusters and storage systems Vacuum system uses 192.168.0.0/24 for DIO but has separate HMI interface to main machine network
• #12: TODO
• #13: Although I cannot detail ALL of the plant I’m going to discuss one block of equipment – Turbo pump set. Gate valve is pneumatically operated with CDA and has open and close ports Open and close states are checked with SPDT microswitches providing 4-wire monitoring Angle valves have subset of these functions and so common code AOI can be reconfigured Turbo pumps runs at up to 45,000 RPM, risk of damage to equipment The Controller provides VFD power to Turbo and monitors states and faults Turbo Controller interfaced to the PLC using Profibus (AnyBus module) Gauges are power from +24V and output 0-10V in log scale (1-9V is valid) Gauge types used to configure logic to correctly scale engineering units Out of range detection used to signify gauge fault and this is used to check for gauge function before operating equipment Backing pump operation monitored by gauge Backing pump can also be monitored for faults using DI
• #14: TODO
• #24: Mention reliability and flexibility.