Motor Bus Transfer Applications Issues and Considerations

Based on the May 2012 Report of the IEEE Power System Relaying Committee Rotating Machinery Protection Subcommittee

and IEEE Std C37.96-2012 Guide for AC Motor Protection, Clause 6.4 Motor bus transfer (MBT)

• Introduction
• Why Transfer Motor Load Sources
• Basic Application Configurations
  • Primary-Backup
  • Main-Tie-Main
  • Multiple-Option Source Selection
• Motor Bus Transfer Classification – Methods & Modes
  • Automatic and Manual
  • Closed Transition Method – Hot Parallel Transfer
  • Open Transition Method – Fast, In-Phase, Residual w/Case Study
  • Open Transition Modes – Simultaneous, Sequential
• Transfer Initiate, Inadvertent External Operation, Lockouts
• Load Shed During Transfer
• Conditions Across Normally Open Startup or Bus Tie Breaker – Before / During Transfer
  • Effects of a Fault
  • Out-of-Step (OOS) Generator Trip
  • System Separation between Incoming Supply Sources
  • Supply Source Transformer Winding Phase Shift
  • Transient Effects upon Disconnect of Motor Loads
  • Motor and Load Characteristic Effects on MBT
• Resultant V/Hz Limits – ANSI Standard C50.41-2012
• Bus Transfer Spin Down Testing, Acceptance Testing, Setting Considerations
• Spin Down Analysis & Settings Calculations – Case Study
• Sequential vs. Simultaneous Transfer, The Need for Speed – Case Study
• IEEE Fast Transfer Sync Check Relay Performance Test Protocol Results
• IEEE Residual Voltage Transfer Relay Performance Test Protocol Results
• Motor Bus Transfer System Dynamic Performance Test Protocol Results and Observations
• A Motor Bus Transfer Torque Ratio Criterion applied to Live Open Transition Transfers Under Normal Operating Load Conditions – Observations and Conclusions
• Test Results from Modeling of Transient Currents and Torques on Motors during Residual Voltage Motor Bus Transfer
• Conclusions

Speaker(s): CEO, Beckwith Electric Co., Inc.,

Location:
Room: Conference Room 4C & 4D
Bldg: Bechtel Tower
3000 Post Oak Blvd
Houston, Texas
77056