Plant Term 2

• Worker Protection Practices
• The rules and procedures that govern how equipment is isolated
• -used at all integrated generating stations

• On the station one line diagram with a dotted line
• in the Joint Local Operating Order

BCH FVO T&D Control Centre

Generation staff at site

• 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

• 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)

• 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

1J-11

The Generation Region

T&D FVO Control Centre (PO)

PO assigns O/R UTAI appropriate one-line perimeter device to a WPP Cat D worker

• 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)

• Protection System is each individual protective arrangement
• Protection Scheme is the whole co-ordinated combination of each individual protection arrangement

Only a minimum portion of the power system should be disconnected to isolate a fault

Schemes must be able to discrimminate between signals which require action, and those that do not

Ability to operate without failure whenever a fault or abnormal condition exists

Schemes must relate to each other so they operate in the right order

• Primary Protection and Standby Protection(backup)
• -increased dependability
• -one protection may be removed for maintenance and the equipment reamain protected

• Current will rise
• Voltage will fall

• Provides useable quantities of voltage and current for:
• metering and control
• protective relays

Voltage Transformer: provides low value of voltage proportional to system voltage(120v)

Current Transformer: provides low value of current proportional to system current(5 A)

The amount of load connected to the secondary of the CT (ohmic value)

Could saturate the CT, no longer accurately reflect system current

Yes. But the concern is what relays use this information and what impact that would have on the system

No. Dangerous voltages could occur damaging equipment and/or workers

• The section of power system that a particular protection covers
• defined by the system they protect
• boundaries determined by the location of CTs

• The section of power system that is tripped by protection
• boundaries determined by the CB locations

Protection zones are typically 'overlapped' to prevent the possibility of unprotected areas

• 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

• Provide a record of the relay's operation
• Electromechanical relay targets = 'flag' drops down
• Digital relays = LED lights indicate operation

Used for analysis of 3 phase electrical power systems using vectors for the three phase quantities

• 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

• 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)

• 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

• Zero Sequence Overvoltage Relay
• Third Harmonic Voltage Differential Relay

Differential Relays(87)

• The governor will respond to limit overspeed
• Overspeed Tripping Relay(12) will operate if the governor fails

• Reverse Power Relay(32) protects the unit(detects power flow INTO the generator)
• This Relay is blocked when the unit is in Sync/Cond

• Differential protection(87):
• Current Differential
• Ground Differential

• Gas Relays(63)
• Sudden Pressure Relays(63)
• Conservator low oil device
• Oil Temperature
• Winding Temperature
• Pressure Releif devices

• 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)

• 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)

• 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

• Remedial Action Scheme
• Automatic protection system designed to detect abnormal or predetermined system conditions, and take actions to maintain reliability

• Maintain angular stability
• Control frequency
• Prevent thermal overload
• Voltage control

• Generation Shedding(GenShed)
• Immediately disconnects generator to reduce amount of power being transmitted on to the system following a transmission contingency
• Maintains angular stability

• TC's responsibility
• Automatically through EMS TSA-PM
• Flashing 'c' beside CB indicates GenShed armed

• GEN DUMP RECEIVED
• 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

1T-38

• 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

• BCHydro Generation Line of Business(GLoB)
• 3G-XXX-02

• Status of breaker/disconnect or other equipment has changed
• Color code=RED

• 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

• Urgent alarm requiring immediate maintenance response
• Call field staff
• Enter in CROW
• Color Code=Purple

• Semi-urgent alarm
• Call field staff between 8:00-22:00 7 days/week
• Enter in Crow
• Color Code=Dark Green

• Non-urgent alarm
• Enter in CROW
• No call out required
• Color Code=Light Green

• Information Only
• No need to enter in CROW or call out unless alarm relates to a Station Security event
• Color Code=Black

Nuisance alarms are moved to Priority 7

Blank(spare)

True

• 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)

• Generator Protection Operations
• Generation Shedding (GenShed)

• 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

• 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

Starting a generating unit without an external source of station service

• 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

• 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

• REV - Revelstoke
• CMS - Chekamus
• COM - Clowhom
• ASH - Ash River
• RPG - Rupert Gas
• SON - Seton

Environmental violations relating to Water Conveyance

• Instructions to operate NPRF facilities
• PSOSE initiates all WC instructions

• T&D FVO maintains O/R
• Because SEV SPOGs can be remotely operated

• Yes
• For flood routing, dam safety operation, maintaining a steady forebay
• Enter into 'WC Implementation Creation'

'Other' operations and captured information not already logged in SCADA, DCM, CM, or CROW requires proper hand written Logging

• '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

• Supervisory Control And Data Acquisition
• OO=1T-34

• 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)

• 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

• 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

• 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

• 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

Control Room Operations Window