Plant Term 2

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  1. What is WPP. Where is it used
    • Worker Protection Practices
    • The rules and procedures that govern how equipment is isolated
    • -used at all integrated generating stations
  2. How are PSSP/WPP boundaries identified
    • On the station one line diagram with a dotted line
    • in the Joint Local Operating Order
  3. Who holds O/A for PSSP equipment at generating stations
    BCH FVO T&D Control Centre
  4. Who holds O/A for WPP equipment at generating stations
    Generation staff at site
  5. What is the procedure for establishing work protection for equipment located on the WPP side of the WPP/PSSP boundary
    • The PO assigns O/R UTAI the appropriate one-line perimeter isolating device to a WPP Cat D worker
    • The WPP worker then performs his Isolation and LockOut
  6. What are 2 methods of isolation for work on equipment in WPP area that requires isolation in PSSP area
    • GOI Procedures
    • -the FVO PIC can issue a GOI
    • -the isolating device is located in a distant remote location
    • Transfer of O/A Procedures
    • -The isolating device is located in the same station/switchyard(PSSP side)
  7. What are 2 methods of isolation for work on equipment in PSSP area that requires isolation in WPP area
    • PSSP Procedures
    • -The WPP PIC can issue a GOI
    • -the isolating device is located in switchyard(WPP side), but PSSP work site is in a distant remote location
    • WPP Procedures
    • -transfer of O/A to a WPP Cat D worker
    • -isolating device is located in switchyard(PSSP side), but PSSP work site is in distant remote location
  8. What Operating Order defines O/A and O/R of NPRF facilities
  9. Who retains O/A of station service at generating stations
    The Generation Region
  10. Who retains O/R on the WPP side at generating stations
    T&D FVO Control Centre (PO)
  11. What is procedure for assigning O/R of station service facilities
    PO assigns O/R UTAI appropriate one-line perimeter device to a WPP Cat D worker
  12. What is purpose of protection
    • To remove a fault before it takes down the entire system
    • It is able to detect the fault and clear it through fault clearing devices (CBs)
  13. What is difference between a protection system and a protection scheme
    • Protection System is each individual protective arrangement
    • Protection Scheme is the whole co-ordinated combination of each individual protection arrangement
  14. What is Selectivity(pertaining to protective relaying)
    Only a minimum portion of the power system should be disconnected to isolate a fault
  15. What is Security(pertaining to protective relaying)
    Schemes must be able to discrimminate between signals which require action, and those that do not
  16. What is Reliability(pertaining to protective relaying)
    Ability to operate without failure whenever a fault or abnormal condition exists
  17. What is Coordination(pertaining to protective relaying)
    Schemes must relate to each other so they operate in the right order
  18. What are 2 types of redundant protection?Why
    • Primary Protection and Standby Protection(backup)
    • -increased dependability
    • -one protection may be removed for maintenance and the equipment reamain protected
  19. What happens to current and voltage in a fault condition
    • Current will rise
    • Voltage will fall
  20. What are two reasons for utilizing instrument transformers
    • Provides useable quantities of voltage and current for:
    • metering and control
    • protective relays
  21. What is a VT
    Voltage Transformer: provides low value of voltage proportional to system voltage(120v)
  22. What is a CT
    Current Transformer: provides low value of current proportional to system current(5 A)
  23. With respect to a CT, what is burden
    The amount of load connected to the secondary of the CT (ohmic value)
  24. How does exceeding burden impact a CT
    Could saturate the CT, no longer accurately reflect system current
  25. Can VT secondaries be opened when they are energized
    Yes. But the concern is what relays use this information and what impact that would have on the system
  26. Can CT secondaries be opened when they are energized
    No. Dangerous voltages could occur damaging equipment and/or workers
  27. What is a Protection Zone
    • The section of power system that a particular protection covers
    • defined by the system they protect
    • boundaries determined by the location of CTs
  28. What is a Tripping Zone
    • The section of power system that is tripped by protection
    • boundaries determined by the CB locations
  29. What is overlap(pertaining to protection)
    Protection zones are typically 'overlapped' to prevent the possibility of unprotected areas
  30. What is breaker fail protection
    • A generator zone protection senses a generator fault and initiates protection operation. If the CB fails to open, 'Breaker Fail' protection operates to trip the adjacent zone
    • Breaker fail monitors for fault current flow through the CB that failed to open
  31. What is purpose of relay targets
    • Provide a record of the relay's operation
    • Electromechanical relay targets = 'flag' drops down
    • Digital relays = LED lights indicate operation
  32. What are symmetrical components
    Used for analysis of 3 phase electrical power systems using vectors for the three phase quantities
  33. What is meant by Positive Sequence
    • Generators produce positive sequence voltage and current
    • Currents and voltages have a positive phase rotation
    • Each phase is equal in magnitude
    • Under balanced conditions only positive sequence exists
  34. What is meant by Negative Sequence
    • May exist in addition to positive sequence if conditions become unbalanced due to unbalanced loads or a fault
    • Unbalanced currents and voltages between phases result in Negative Sequence (negative phase rotation)
  35. What is meant by Zero Sequence
    • When conditions are unbalanced and there is a path to ground, positive, negative, and Zero Sequence quantities will exist
    • For zero sequence, phase quantities are equal in magnitude and in phase
  36. What 2 relays are used to detect stator phase to ground faults
    • Zero Sequence Overvoltage Relay
    • Third Harmonic Voltage Differential Relay
  37. What relay is used to detect stator phase to phase faults
    Differential Relays(87)
  38. How is a generator protected from overspeed
    • The governor will respond to limit overspeed
    • Overspeed Tripping Relay(12) will operate if the governor fails
  39. How is a generator protected from motoring
    • Reverse Power Relay(32) protects the unit(detects power flow INTO the generator)
    • This Relay is blocked when the unit is in Sync/Cond
  40. What electrical protective relays are in place on a generating step-up transformer
    • Differential protection(87):
    • Current Differential
    • Ground Differential
  41. What non-electrical protective relays are in place on a generating step-up transformer
    • Gas Relays(63)
    • Sudden Pressure Relays(63)
    • Conservator low oil device
    • Oil Temperature
    • Winding Temperature
    • Pressure Releif devices
  42. Why is it important to detect a field ground on a synchronous generator? Which relay
    • A loss of symmetrical magnetic flux will result(shaft vibration and overheating of windings)
    • 2 field grounds will cause a short circuit unbalance on field windings
    • Ground Detector relay(64)
  43. What is meant by 'loss of field'? Which relay
    • A loss of excitation
    • Leads to a decrease in terminal voltage, loss of field strength, loss of electrical synchronization
    • A generator with loss of excitation will draw MVARs (motoring)
    • Field Relay(40)
  44. Describe importance of detecting 'loss of field'
    What helps protect against this
    • Prevents generator from losing synchronism to system and tripping off
    • Magnetic field around field windings becomes too weak from under-excitation to maintain electrical synchronization
    • Possibly lead to pole slip
    • Resultant loss of MW could lead to system breakup and major outage
    • MEL - Minimum Excitation Limiter prevents excitation from reaching underexcited condition
  45. What is a RAS
    • Remedial Action Scheme
    • Automatic protection system designed to detect abnormal or predetermined system conditions, and take actions to maintain reliability
  46. What is purpose of RAS
    • Maintain angular stability
    • Control frequency
    • Prevent thermal overload
    • Voltage control
  47. What is the most typical RAS scheme
    • Generation Shedding(GenShed)
    • Immediately disconnects generator to reduce amount of power being transmitted on to the system following a transmission contingency
    • Maintains angular stability
  48. How is GenShed armed
    • TC's responsibility
    • Automatically through EMS TSA-PM
    • Flashing 'c' beside CB indicates GenShed armed
  49. What alarms would GenShed send. What is plan of action
    • Other related CB Open alarms
    • Action plan:
    • Determine if Unit can be restarted(not locked out)
    • Determine if transmission line is 'in'
    • Attempt to restart and synchronize
  50. What OO documents Station Alarms
  51. What is difference between station alarms and analog alarms
    • Station alarms: Station alarms which ring at stations are telemetered to the BCHydro Control Centre EMS
    • Analog alarms: generated solely within the BCHydro Control Centre EMS through Alarm Application
  52. Who determines the priorities for alarms at BCHydro Generating stations
    • BCHydro Generation Line of Business(GLoB)
    • 3G-XXX-02
  53. What is a Priority 1 Alarm
    • Status of breaker/disconnect or other equipment has changed
    • Color code=RED
  54. What is a Priority 2 Alarm
    • Analog Alarms - PO action required
    • Includes alarms where PO action required on remote equipment(creep, overload alarms) *CROW entry required if can not clear alarm*
    • Color Code=Brown
  55. What is a Priority 3 Alarm
    • Urgent alarm requiring immediate maintenance response
    • Call field staff
    • Enter in CROW
    • Color Code=Purple
  56. What is a Priority 4 Alarm
    • Semi-urgent alarm
    • Call field staff between 8:00-22:00 7 days/week
    • Enter in Crow
    • Color Code=Dark Green
  57. What is a Priority 5 Alarm
    • Non-urgent alarm
    • Enter in CROW
    • No call out required
    • Color Code=Light Green
  58. What is a Priority 6 Alarm
    • Information Only
    • No need to enter in CROW or call out unless alarm relates to a Station Security event
    • Color Code=Black
  59. What is a Priority 7 Alarm
    Nuisance alarms are moved to Priority 7
  60. What is a Priority 8 Alarm
  61. T or F - Priority of an alarm may become higher based on other associated alarms that come in at the same time
  62. What is primary difference in callout procedures for emergency conditions versus non-emergency conditions
    • Emergency: The PO will call out crews first and call the Standby Manager at the first opportunity
    • Non-emergency: The Standby Manager shall be contacted first(he will decide on best course of action)
  63. What can single generating unit trips be caused by
    • Generator Protection Operations
    • Generation Shedding (GenShed)
  64. What is the PO's response to a generator trip
    • Restore water flows
    • Aid the GC in replacing the generation
    • Aid the TC and GO in any voltage issues
    • Attempt to resync the unit but not load it
    • Investigate the cause of outage, report to PSOSE, enter in CROW
  65. What is an Islanding Event
    • A pocket of generation and load operating at a given frequency, but which is no longer synchronously tied to the rest of the system
    • -loss/outage of transmission facility
    • -PO should not make generation changes without GC and TC approval
    • -OO=7T-10
  66. What is a Blackstart
    Starting a generating unit without an external source of station service
  67. When might a PO be asked to blackstart a generating station
    • Asked by the GC and TC to Blackstart a station as the first step in restoration activities
    • A disturbance has de-energized a large area of the BES
  68. What is a typical Blackstart procedure
    • Obtain a source of station service(typically backup diesel gen)
    • Put through an Auto-Start on the unit
    • Open all generating station switchyard CBs
    • Close generator unit CB to energize step-up transformer(sync-bypass)
    • Continue to sync generators to one another under direction of the GC and TC
  69. What are the Remote Blackstart plants
    • REV - Revelstoke
    • CMS - Chekamus
    • COM - Clowhom
    • ASH - Ash River
    • RPG - Rupert Gas
    • SON - Seton
  70. What type of environmental incident is the PO responsible to report
    Environmental violations relating to Water Conveyance
  71. What is a Water Conveyance instruction
    • Instructions to operate NPRF facilities
    • PSOSE initiates all WC instructions
  72. Who maintains O/R of SEV NPRFs
    • T&D FVO maintains O/R
    • Because SEV SPOGs can be remotely operated
  73. Can the PO operate NPRF facilities without notifying PSOSE
    • Yes
    • For flood routing, dam safety operation, maintaining a steady forebay
    • Enter into 'WC Implementation Creation'
  74. What is purpose of paper based Log
    'Other' operations and captured information not already logged in SCADA, DCM, CM, or CROW requires proper hand written Logging
  75. What is recorded on a paper based Log
    • 'Anything' not captured using electronic logging
    • Shift Change notes
    • Record of O/Rs assigned
    • Entry/Exit and Manchecks
    • Critical water levels and flows
    • Callout info
  76. What does SCADA stand for
    • Supervisory Control And Data Acquisition
    • OO=1T-34
  77. Explain SCADA
    • From a central location:
    • -SCADA monitors, controls, alarms plants, alarms regional electric systems
    • Provides supervisory control of switchyard equipment, generators, spillway facilities
    • Provides telemetry back to control centres(MW, MVAR, KV, Amps, Freq)
  78. What are 4 key functions of SCADA
    • Telemetry: communication of data
    • Status Reporting: reports change of status of a device
    • Alarm Reporting: reports corresponding alarm points to control centre
    • Supervisory Control: allows remote operation of devices
  79. What are 3 major components of SCADA
    • Master Station: the control centre (FVO & SIO)
    • Remote Terminal Units(RTUs): the send/receive point at the station or equipment
    • Communication Facility: Microwave signals/towers, power line carriers, etc
  80. What is CM?  Purpose?
    • Commercial Management
    • Delivers specific NPRF intstructions
    • Stores data for all water conveyances
    • Provides a clear record of NPRF facility movements
    • GLoB (BCH Generation Line of Business) is the owner
    • OO=1T-53
  81. What is DCM?  Purpose?
    • Dispatch and Compliance Monitoring
    • Delivers specific generator instructions
    • Security measures built in to protect from trans. marketers
    • GLoB (BCH Generation Line of Business) is the owner
    • OO=1T-56
  82. What does CROW stand for
    Control Room Operations Window
Card Set:
Plant Term 2
2014-05-12 11:33:00
Plant Term

Plant Term 2
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