L01.01: Electrical Power System Orientation

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  1. Daily increases and decreases in generation and load, lightning and...
    ...other "naturally occurring" events, equipment failure and maintenance activities affect the balance.
  2. Without the balance of load and generation, the system...
    ...may become unstable and alrge scale blackouts can occur
  3. The customer demand for electricity (load) is constantly...
    ...changing throughout the day
  4. Peak electrical loads occur approx. at...
    • 11:30AM; and
    • 5:30PM to 8:00PM
  5. The minimum demand for electricity occurs...
    ...Sunday at 3:00AM
  6. Demand peaks are dependent on various factors including...
    • location
    • time of day
    • type of load
    • time of year
    • weather
  7. Random, small variations in frequency are normal, as loads come on and off and...
    ...generators modify their output to follow demand changes
  8. Large deviations in frequency can cause the speed of generators to fluctuate, leading to...
    ...vibrations that can damage generator turbine blades and other equipment
  9. Failure to match generation to demand, when generation exceeds demand, causes the...
    ...frequency of and AC power system to increase
  10. Failure to match generation to demand, when generation is less than demand, causes the...
    ...frequency of and AC power system to deccrease
  11. The frequency of Hydro One's AC power system is...
    ...60 cycles per second (60 Hertz)
  12. Extreme low frequencies cause by insufficient generation can trigger automatic...
    • ...under-frequency load shedding, which takes blocks of customers off-line in order to prevent the total collapse of the system
    • Image Upload
  13. Power is utilized in two different ways:
    • Three-phase
    • Single-Phase
  14. Power plants produce three different phases of...
    ...AC power simultaneously
  15. Power plants produce 3-phases of AC power, which synchronized and...
    ...offset by 120 degrees
  16. There are ______ coming out of every generator connected to the transmission grid
    ...three wires...
  17. A transmission tower typically has 3 wires connected to it, known as a single transmission line or circuit, but...
    ...it actually has three phases
  18. Single-phase refers to...
    ...the utilization of one of three phases
  19. In 3 phase power, at any given moment, one of the three phases is...
    ...nearing peak
  20. As one of three phases is always nearing peak, high-power three phase motors and equipment have...
    ...even power output
  21. As earth is a good conductor, it makes...
    ...a good return path for electrons
  22. The power system uses ______ as a return path or ground in the power system.
    the Earth
  23. The ground wire (or fourth wire) provides and low impedance path for...
    ...return and fault current to the TS
  24. Alternating Current (AC) is...
    ...oscillating power
  25. Direct current (DC) refers to a steady...
    ...stream of electrons that flow in one direction only
  26. In DC power, electrons flow in once direction only, from the...
    ...negative to the positive terminal of at a battery
  27. It is easy to convert __ power to __ power
    AC; DC
  28. Large electrical generators produce 3-phase...
    ...AC power
  29. Large electrical generators produce 3-phase AC power; conversion to...
    DC power involves and extra step (and is expensive)
  30. DC is only economically feasible for...
    ...very long lines such as Hydro Quebec (750kV)
  31. Transformers must have AC to operate.  The grid depends on transformers to...
    ...change the voltage of lines for either transmission or distribution.
  32. Advantages of AC power over DC power include:
    • Transformers need AC power to operate
    • Large Generators produce AC power
    • Conversion to AC power is easy
    • Conversion to DC power takes an extra step
    • Conversion to DC power is expensive
    • DC is only economically feasible for very long lines
  33. Ontario's Electrical power system is..
    ...one of the largest in North America
  34. Ontario's Electrical system covers_____ km2
    640,000 km2
  35. Ontario's Electrical system as ___ Tx Stations
    273 Tx Stations
  36. Ontario's Electrical system has ____ km of Tx Lines
    28,500 km
  37. Ontario's Electrical system has ____km of Underground Cable
    272 km
  38. In 2003, electricity transmitted in Ontario was...
    152 TWh
  39. In 2003, electricity transmitted in Ontario was transmitted to a total of ____ customers
    12 million customers
  40. In 2003, electricity transmitted in Ontario was transmitted to a total of ____ Hydro One customers
    1 million customers
  41. In 2003, Ontario had the capacity to generate _______ of power
    30,000 MW
  42. In 2003, Ontario had the capacity to generate 30,000 MW of power, which ___% was owned by...
    ...OPG
  43. Ontario's Interconnections has approximately ______ of import/export capability
    3000 MW
  44. Electricity is produce by spinning and electromagnet...
    ...inside a coil of wire in a generator to create a flow of electrons
  45. Hydroelectric stations use falling water to keep ______ spinning
    the electromagnet spinning
  46. Water power is used extensively in most power systems by:
    (1)____________________________
    (2) the backed up water produces the necessary head, or difference in elevation, required to power a generator (the flow of the river water becomes the driving force)
    (3)The water, at the higher level, is channeled down a pipe or "penstock", striking the blades of a turbine runner at the bottom
    (4) The turbine is a type of water wheel connected to the generator
    (5) The runner and generator rotating together provide the power for the production of electricity
    (6) The water then passes out through the draft tube to the trail race and joins the main stream of the rive
    (1) a dam is erected at a suitable location on a waterway
  47. Water power is used extensively in most power systems by:
    (1)A dam is erected at a suitable location on a waterway
    (2) __________________________
    (3)The water, at the higher level, is channeled down a pipe or "penstock", striking the blades of a turbine runner at the bottom
    (4) The turbine is a type of water wheel connected to the generator
    (5) The runner and generator rotating together provide the power for the production of electricity
    (6) The water then passes out through the draft tube to the trail race and joins the main stream of the rive
    ...(2) the backed up water produces the necessary head, or difference in elevation, required to power a generator (the flow of the river water becomes the driving force)
  48. Water power is used extensively in most power systems by:
    (1)A dam is erected at a suitable location on a waterway
    (2) the backed up water produces the necessary head, or difference in elevation, required to power a generator (the flow of the river water becomes the driving force)
    (3)______________________________
    (4) The turbine is a type of water wheel connected to the generator
    (5) The runner and generator rotating together provide the power for the production of electricity
    (6) The water then passes out through the draft tube to the trail race and joins the main stream of the river
    ...(3) The water, at the higher level, is channeled down a pipe or "penstock", striking the blades of a turbine runner at the bottom
  49. Water power is used extensively in most power systems by:
    (1)A dam is erected at a suitable location on a waterway
    (2) the backed up water produces the necessary head, or difference in elevation, required to power a generator (the flow of the river water becomes the driving force)
    (3)The water, at the higher level, is channeled down a pipe or "penstock", striking the blades of a turbine runner at the bottom
    (4) ______________________________
    (5) The runner and generator rotating together provide the power for the production of electricity
    (6) The water then passes out through the draft tube to the trail race and joins the main stream of the river
    (4) The turbine is a type of water wheel connected to the generator
  50. Water power is used extensively in most power systems by:
    (1)A dam is erected at a suitable location on a waterway
    (2) the backed up water produces the necessary head, or difference in elevation, required to power a generator (the flow of the river water becomes the driving force)
    (3)The water, at the higher level, is channeled down a pipe or "penstock", striking the blades of a turbine runner at the bottom
    (4) The turbine is a type of water wheel connected to the generator
    (5) _____________________________
    (6) The water then passes out through the draft tube to the trail race and joins the main stream of the river
    (5) The runner and generator rotating together provide the power for the production of electricity
  51. Water power is used extensively in most power systems by:
    (1)A dam is erected at a suitable location on a waterway
    (2) the backed up water produces the necessary head, or difference in elevation, required to power a generator (the flow of the river water becomes the driving force)
    (3)The water, at the higher level, is channeled down a pipe or "penstock", striking the blades of a turbine runner at the bottom
    (4) The turbine is a type of water wheel connected to the generator
    (5) The runner and generator rotating together provide the power for the production of electricity
    (6) _______________________
    (6) The water then passes out through the draft tube to the trail race and joins the main stream of the river
  52. Several generators usually are in operation at the same site.  This supplies...
    ...flexibility for complete utilization of the water available
  53. As hydroelectric generators can be started up and shutdown very quickly, they are suitable for...
    both base loading and peak loading
  54. Base loading is...
    ...the constant part of the load
  55. Peak loading is...
    ... the extra power part of the load that is only required at high demand periods
  56. While the generator is condensed, it is possible to...
    ...quickly control water flow through the turbine by adjusting the gates
  57. When a generator is condensed, it is...
    ...synchronized to the system and the wicket gates are closed
  58. Thermal electric generating is supplied by...
    steam, caused by the heating of water
  59. In thermal generation, the heating of water (to create steam) is accomplished by...
    • burning of fossil fuels
    • release of heat from the splitting of an uranium atom
  60. In a station using coal to heat water:
    (1) ______________________________
    (2)When This water turns to steam, it moves at high speed and pressure to operate a turbine.
    (3)the steam pushes the blades of the turbine, which is connected to a shaft or rotor, causing the rotor to spin.-the spinning rotor is A large electromagnet that produces rotating magnetic fields.
    (4) These fields move across coils of wire in the generator to produce electricity.
    (5) the steam from the turbine is cooled and condensed back to water by using cooling water from the river or lake. it is then reused in the boiler.
    (1)Finely crushed coal is burned in A large industrial furnace with walls lined with water-filled tubes to generate steam.
  61. In a station using coal to heat water:
    (1)Finely crushed coal is burned in A large industrial furnace with walls lined with water-filled tubes to generate steam.
    (2)__________________________
    (3)the steam pushes the blades of the turbine, which is connected to a shaft or rotor, causing the rotor to spin.-the spinning rotor is A large electromagnet that produces rotating magnetic fields.
    (4) These fields move across coils of wire in the generator to produce electricity.
    (5) the steam from the turbine is cooled and condensed back to water by using cooling water from the river or lake. it is then reused in the boiler.
    (2)When This water turns to steam, it moves at high speed and pressure to operate a turbine.
  62. In a station using coal to heat water:
    (1)Finely crushed coal is burned in A large industrial furnace with walls lined with water-filled tubes to generate steam.
    (2)When This water turns to steam, it moves at high speed and pressure to operate a turbine.
    (3)the steam pushes the blades of the turbine, which is connected to a shaft or rotor, causing the rotor to spin.-the spinning rotor is A large electromagnet that produces rotating magnetic fields.
    (4) ______________________
    (5) the steam from the turbine is cooled and condensed back to water by using cooling water from the river or lake. it is then reused in the boiler.
    (4) These fields move across coils of wire in the generator to produce electricity.
  63. In a station using coal to heat water:
    (1)Finely crushed coal is burned in A large industrial furnace with walls lined with water-filled tubes to generate steam.
    (2)When This water turns to steam, it moves at high speed and pressure to operate a turbine.
    (3) ______________________________
    (4) These fields move across coils of wire in the generator to produce electricity.
    (5) the steam from the turbine is cooled and condensed back to water by using cooling water from the river or lake. it is then reused in the boiler.
    (3)the steam pushes the blades of the turbine, which is connected to a shaft or rotor, causing the rotor to spin.-the spinning rotor is A large electromagnet that produces rotating magnetic fields.
  64. In a station using coal to heat water:
    (1)Finely crushed coal is burned in A large industrial furnace with walls lined with water-filled tubes to generate steam.
    (2)When This water turns to steam, it moves at high speed and pressure to operate a turbine.
    (3)the steam pushes the blades of the turbine, which is connected to a shaft or rotor, causing the rotor to spin.-the spinning rotor is A large electromagnet that produces rotating magnetic fields.
    (4) These fields move across coils of wire in the generator to produce electricity.
    (5) ______________________________
    (5) the steam from the turbine is cooled and condensed back to water by using cooling water from the river or lake. it is then reused in the boiler.
  65. Nuclear power is produced in the following manner:
    (1) ____________________________
    (2)Heavy water, that is constantly being pumped through the fuel channels in the reactor, takes the heat from the fuel bundles up to boilers above the reactor
    (3) In the boilers, the heated heavy water heats up ordinary water to make steam
    (4)The discharged steam is condensed using cooling water from a lake and returned to the boilers to repeat the process
    (1)The heat has to be moved to boilers to make steam (In a CANDU® reactor, heavy water is used)
  66. Nuclear power is produced in the following manner:
    (1)The heat has to be moved to boilers to make steam (In a CANDU® reactor, heavy water is used)
    (2) __________________________
    (3) In the boilers, the heated heavy water heats up ordinary water to make steam
    (4)The discharged steam is condensed using cooling water from a lake and returned to the boilers to repeat the process
    (2)Heavy water, that is constantly being pumped through the fuel channels in the reactor, takes the heat from the fuel bundles up to boilers above the reactor
  67. Nuclear power is produced in the following manner:
    (1)The heat has to be moved to boilers to make steam (In a CANDU® reactor, heavy water is used)
    (2)Heavy water, that is constantly being pumped through the fuel channels in the reactor, takes the heat from the fuel bundles up to boilers above the reactor
    (3) ____________________
    (4)The discharged steam is condensed using cooling water from a lake and returned to the boilers to repeat the process
    (3) In the boilers, the heated heavy water heats up ordinary water to make steam
  68. Nuclear power is produced in the following manner:
    (1)The heat has to be moved to boilers to make steam (In a CANDU® reactor, heavy water is used)
    (2)Heavy water, that is constantly being pumped through the fuel channels in the reactor, takes the heat from the fuel bundles up to boilers above the reactor
    (3) In the boilers, the heated heavy water heats up ordinary water to make steam
    (4)______________________
    (4)The discharged steam is condensed using cooling water from a lake and returned to the boilers to repeat the process
  69. An electrical grid (Tx system) may be interconnected with other systems, thereby enabling...
    ...one system to help another suffering power shortage or an interruption
  70. A large interconnected system has_______ and _________ to adverse the affects of losing generation or transmission service.
    • more generation
    • more inertia
  71. Inertia is the resistance of any physical object to any change in its motion (including change in direction.  In other words, it...
    is the tendency of object to keep moving in a straight line at constant linear velocity, or to keep still
  72. The Ontario grid is connected with other grid systems in...
    • Manitoba
    • New York
    • Michigan
  73. Providing electricity involves:
    • real time assessment
    • control and coordination or electricity production at generators
    • moving electricity across an interconnected network of Tx lines
    • delivery of electricity to millions of customers via Dx network
  74. Electricity flow at close to the speed of...
    • ...light
    • 186,000 miles/second
    • 297,600 km/second
  75. Electricity is not economically storable in large quantities (i.e. batteries), therefore...
    ...electricity must be produced the instant it is used
  76. Electricity flows freely along all available paths from...
    ...generators to the loads in accordance with the laws of physics
  77. Electricity flows freely from generators to loads, dividing among all connected flow paths in the network, in inverse...
    ...inverse proportion to the impedance (resistance plus reactance) or each path
  78. A typical electrical power system includes:
    1. __________________
    2. Generating Switchyard
    3. Transmission Line
    4. Switching Station
    5. Large Transformer Station
    6. Step-down Transformer Station
    7. Distribution Station
    1. Generating Statio
  79. A typical electrical power system includes:
    1. Generating Station;
    2. _______________;
    3. Transmission Line;
    4. Switching Station;
    5. Large Transformer Station;
    6. Step-down Transformer Station;
    7. Distribution Station
    2. Generating Switchyard;
  80. A typical electrical power system includes:
    1. Generating Station;
    2. Generating Switchyard;
    3. ______________;
    4. Switching Station;
    5. Large Transformer Station;
    6. Step-down Transformer Station;
    7. Distribution Station
    3. Transmission Line
  81. A typical electrical power system includes:
    1. Generating Station;
    2. Generating Switchyard;
    3. Transmission Line;
    4. _______________;
    5. Large Transformer Station;
    6. Step-down Transformer Station;
    7. Distribution Station
    4. Switching Station
  82. A typical electrical power system includes:
    1. Generating Station;
    2. Generating Switchyard;
    3. Transmission Line;
    4. Switching Station;
    5. _________________;
    6. Step-down Transformer Station;
    7. Distribution Station
    5. Large Transformer Station
  83. A typical electrical power system includes:
    1. Generating Station;
    2. Generating Switchyard;
    3. Transmission Line;
    4. Switching Station;
    5. Large Transformer Station;
    6. _______________;
    7. Distribution Station
    6. Step-down Transformer Station
  84. A typical electrical power system includes:
    1. Generating Station;
    2. Generating Switchyard;
    3. Transmission Line;
    4. Switching Station;
    5. Large Transformer Station;
    6. Step-down Transformer Station;
    7. ____________________
    7. Distribution Station
  85. A typical hydro electric generating Station (GS) includes:
    1. _____________
    2. Generators
    3. Turbine Runner
    4. Scroll Case
    5. Draft Tube
    6. Tailrace
    1. Penstocks
  86. A typical hydro electric generating Station (GS) includes:
    1. Penstocks
    2. ____________
    3. Turbine Runner
    4. Scroll Case
    5. Draft Tube
    6. Tailrace
    2. Generators
  87. A typical hydro electric generating Station (GS) includes:
    1. Penstocks
    2. Generators
    3. ______________
    4. Scroll Case
    5. Draft Tube
    6. Tailrace
    3. Turbine Runner
  88. A typical hydro electric generating Station (GS) includes:
    1. Penstocks
    2. Generators
    3. Turbine Runner
    4. ____________
    5. Draft Tube
    6. Tailrace
    4. Scroll Case
  89. A typical hydro electric generating Station (GS) includes:
    1. Penstocks
    2. Generators
    3. Turbine Runner
    4. Scroll Case
    5. ________________
    6. Tailrace
    5. Draft Tube
  90. A typical hydro electric generating Station (GS) includes:
    1. Penstocks
    2. Generators
    3. Turbine Runner
    4. Scroll Case
    5. Draft Tube
    6. ________________
    6. Tailrace
  91. Elements within a GS switchyard are generally used to transfer power from...
    • ...a low voltage to a high voltage, and connect to the Tx System
    • Image Upload
  92. After electric power is generated at a low voltage, the power is...
    • ...stepped up to a higher voltage by the transformer
    • Image Upload
  93. After electric power is generated at a low voltage, the power is stepped up to a higher voltage by the transformer, then the circuit...
    ...circuit passes through a breaker (i.e. OCB)
  94. At a GS, between the Step-Up Transformer and the Circuit Breaker, there are surge arrestors.  One arrestor is connected...
    ...between each transformer high voltage terminal and ground.
  95. At a GS, between the Step-Up Transformer and the Circuit Breaker, there are surge arrestors.  These surge arrestors is must be located...
    ...located as close as possible to the transformer to provide maximum protection to the windings against lighting strikes and a switching surges
  96. Name 4 types of breakers:
    • 1. OCB
    • 2. ABB
    • 3. Vacuum Breakers
    • 4. SF6 Breakers
  97. Circuit breakers can be opened and closed by the controller or...
    ...opened automatically by protective relay schemes
  98. Circuit breakers can be opened and closed by the controller or opened automatically by protective relay schemes if...
    ...a fault occurs in any part of the adjacent lines or associated quipment
  99. In a GS yard, next to the breaker is a steel structure on which are mounted three disconnect switches who's function...
    ...is to provide a point of separation for isolation and protection of personnel working
  100. Disconnect switches may be operated individually or...
    ...simultaneously (Gang Operation) through mechanical linkages from one control
  101. In a GS yard, adjacent to the disconnect switches are Grounding Switches, which provide...
    ...isolation and remove any electrical charge that may be on the Tx line after it is isolated
  102. Tx Conductors are installed on steel towers to steel arms by...
    hanging or suspension type insulators
  103. Most towers are constructed to carry one or more circuits, with each circuit consisting of...
    three phases (i.e. conductors)
  104. What size lines are installed on steel towers?
    230kV to 500kV
  105. What lines are installed on Steel/Wood Structures?
    115kV lines
  106. Lines below 115kV are usually installed on structures made of:
    • Wood
    • Concrete
    • Steel
    • Fibreglass
  107. Conductors are made of copper or aluminium. Aluminium...
    ...aluminium conductors have a steel core to provide mechanical strength
  108. Sky Wires are installed at the top of towers.  Their function is to...
    ...protect power conductors from direct lightning strikes
  109. A Sky Wire ins connected to ground at regular intervals to...
    ...conduct the lightning charges to earth.
  110. A BUS is a group of conductors to which...
    ...several pieces of equipment or circuits are connected.
  111. In a Large TS, Coordinating Gaps are designed and adjusted to allow...
    ...high voltage [due to lightning] to "spill" over to ground
  112. The operation of Coordinating gaps will likely cause...
    ...protective devices to operate, which will cause a power outage
  113. In a Large TS, and Air Blast Circuit Breaker is designed to open and close electrical circuits.  The contacts open...
    ...under a blast of very dry, high pressure air designed to extinguish ARC.
  114. In a Large TS, usually located adjacent to a heavy load centre where a number of transmission circuits terminate.  It contains a Step-Down Transformer that drops voltage from...
    ...from 230 kV and 500 kV down to 115 kV
  115. In a Large TS, a Switchgear is a...
    ...a compact assembly of switching devices for the control of a smaller distribution network
  116. In a Large TS, a Synchronous Condenser is a rotating machine [much like a generator], whos purpose is to...
    ...to control, correct or regulate the power factor at the station for all conditions of load
  117. In a Large TS, a Capacitor Coupler gives the operator...
    ...an indication of the voltage on that circuit & provide information used for relaying and metering.
  118. In a Small TS, a Step-Down Transformer drops voltage down so if can be carried to Dx stations and industrial plants (or other direct customers).  The out put voltage is typically...
    dropped to 27.6kV or 44kV
  119. In a Small TS, 3 Potential Transformers (PT’s) are connected to the line or bus. Similar in function to the capacitor, their purpose is...
    ...to give a voltage indication to the operator and reduce high voltage to 115 V for metering and protective relaying.
  120. In a Small TS, a High-voltage disconnect switch may be operated...
    ...operated manually or automatically by remote control
  121. In a Small TS, after the disconnect switch, power travels through a...
    ...circuit breaker
  122. In a Small TS, after power travels through the Circuit breaker, it...
    ...reaches the Step-Down Transformer
  123. In a Small TS, after power is stepped-down at the transformer, power travels to...
    ...a Low Voltage Switchgear
  124. In a Small TS, a Low Voltage Switchgear contains breakers, switches, & fuses.  It can then break-off power to service:
    • a large local industry [which will likely contain its own step-down]
    • a grounding transformer – used for protection of the system
    • a 27.6kV Dx circuit via reactors & potheads
    • Dx Station – through a cable, pothead, disc. Switches and 27.6 kV circuit
  125. A pothead is a device that brings three conductors out of...
    ...a cable without allowing moisture to seep in and destroy the insulation
  126. Dx Stations step voltages down to...
    12.5kV to 4.8kV
  127. A fuse consists of a tube which houses a link designed to...
    ...melt when carrying abnormally high current, thus opening the circuit
  128. Feeders from a Dx station will be equipped with Fused Disconnect Switches.  These allow the fuses to blow on a troubled feeders circuit without...
    ...affecting other circuits or parts of the Dx system
  129. When power reaches residential customers and small businesses, Pole Top and Padmount transfoermers reduce the voltage to:
    • 120V for lighting and small appliances
    • 240V for ranges, heaters, and small motors
    • 600V for large motors
  130. Certain GS' changing load causes objectionable changes in downstream river elevations. A dam will be constructed to regulate the discharge to an even flow. The pond ormed by this dam is...
    known as the afterbay, and is fed by the tailrace
  131. A turbine of any kind is used to drive a generator is know as...
    ...a Turbo-Generator
  132. When demand for power is extremely high, it is often cheaper to...
    ...purchase power from the interconnections for short periods than start up the less efficient thermal units
  133. The first commercial electricity in Ontario was produced by water power.  Electricity is controlled by...
    ...a series of switches and breakers
  134. Primary sources of Generation are:
    • Nuclear
    • Hydroelectric
    • Thermal
  135. Alternative Sources of Generation are:
    • interconnections with neighbouring utilities and non-utility generators
    • renewable power (i.e. Wind Turbines, Solar Panels)
    • Emergency Power (diesel generators)

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Author:
Sarah7755
ID:
314077
Filename:
L01.01: Electrical Power System Orientation
Updated:
2016-01-13 20:03:33
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Electrical Power System Orientation
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Electrical Power System Orientation
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