3. Network Overview Ethernet 3 Sets of Redundant Processors perform all PMS logic. Time Sync Processor Performs logging functions and Time Control HMI Servers and Clients Some Remote I/O chassis on “ S2” ControlNet Network Some Remote I/O chassis on “S1” ControlNet Network Some Remote I/O chassis on “ Fast” ControlNet Network All Processors on Separate “Processor” ControlNet Network Field devices connect serially. Gemstarts Serial to Ethernet Converters Breakers. Multilin and Micrologic MCP’s and ICSS and GCP’s
4. External Device Connection Example Remote Enclosure Multilin Serial to TCP Converter S1 CNET Fiber to Other Enclosure Fast CNET Fiber to Other Enclosure Ethernet Fiber to Other Enclosure Micrologic Serial to TCP Converter Gemstart Gemstart Gemstart SWG Control Panels Serial RS485 for Modbus Serial RS485 for Modbus Hardwire I/O DIRIS Hardwire I/O Including Load Shedding Signals Sync-Link Fiber to Other Enclosure S1 Rack Fast Rack
5. Network Protocol Information 1 Sync-Link Fiber (max 300m Typical <100m) Fiber (max 300m Typical <100m) Sync-Link 1 Ethernet/IP Modbus TCP TCP/IP HTTP Fiber Cat-5 Twisted pair Ethernet cable Ethernet Many Modbus RTU 2 wire shielded twisted pair 2 wire shielded twisted pair Serial 4 CIP over ControlNet Fiber (max 3000m Typical 300m) Coaxial shielded cable (max 1000m typical <100m) ControlNet Number of Networks Protocols Used by Network Media Outside Enclosure Media In Enclosure Network
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10. Communication Devices Located in I/O Racks Prosoft Modbus RTU communication module. Allows ControlLogix racks to communicate with modbus RTU devices over RS485. 1756-MCMR Prosoft Modbus TCP communication module. Allows ControlLogix racks to communicate with Modbus TCP devices over Ethernet. 1756-MNETR Allen-Bradley Controlnet Redundant communication module. Allows ControlLogix racks to communicate over ControlNet protocol. Used in all remote racks and in main processor racks to control I/O. 1756-CNBR Allen-Bradley Ethernet Communication module. Allows ControlLogix racks to communicate over Ethernet via Ethernet/IP protocol. Used in main processor racks to share data and communicate with HMI. 1756-ENBT Description Device
14. Emergency Load Shed Example A C B Output: 12MW Reserve: 13MW Output: 20MW Reserve: 5 MW Output: 15MW Reserve 10MW 1. All Generators connected and loaded as shown. 2. Gen A is lost, 15MW of generation must be compensated for in the system. 3. No load is shed as Gen B and C pick up load from their reserve. Example 1 Output: 0MW Reserve: 0MW Output: 23MW Reserve: 2MW Output: 24MW Reserve: 1MW
15. Emergency Load Shed Example A C B Output: 20MW Reserve: 5MW Output: 20MW Reserve: 5 MW Output: 20MW Reserve 5MW 1. All Generators connected and loaded as shown. 2. Gen A is lost, 20MW of generation must be compensated for in the system. 3. Total loads shed: 20MW – 5MW (genC reserve) – 5MW(genB reserve) = 10MW. Example 2 Output: 0MW Reserve: 0MW Output: 25MW Reserve: 0 MW Output: 25MW Reserve 0MW
16. Gradual Load Shed Example A Output: 20MW Reserve Capacity: 5MVA Gradual Shed Threshold: 2MVA Gradual Shed Delay: 5s 1. Generator is connected to a bus and loaded as shown. Gradual Shed Threshold is configured as shown (2MVA) by the operator. 2. Generator Output increases such that Reserve MVA < Threshold MVA 3. One connected load is shed to attempt to unload generator 4. After 5s delay, if Reserve MVA < Threshold MVA then shed next load. If Reserve MVA > Threshold MVA then continue monitoring. Output: 24MW Reserve Capacity: 1MVA Gradual Shed Threshold: 2MVA Gradual Shed Delay: 5s
17. Underfrequency Shed A C BUS A U/F 1. Two Generators connected as shown. Bus A and C are isolated. Underfrequency Settings: Enabled = TRUE Block Size = 5MW Shed Retry Timer = 5s 2. Bus Underfrequency Alarm A becomes active. 3. 5MW of load attached to genA is shed. 4. After 5s, if U/F is still active, 5MW additional load is shed. If U/F is not active, continue monitoring.
