Power System Operations
Power System Operations
Power System Operations
NOVEMBER 2012
ENGR. D. ALPIS
POWER PLANT
A power station or power plant is a facility for the generation of electric power. 'Power plant' is also used to refer to the engine in ships, aircraft and other large vehicles. Some prefer to use the term energy center because it is more accurately describes what the plants do, which is the conversion of other forms of energy, like chemical energy, gravitational potential energy or heat energy into electrical energy.
POWER PLANT
At the center of nearly all power stations is a generator, a rotating machine that converts mechanical energy into electrical energy by creating relative motion between a magnetic field and a conductor. The energy source harnessed to turn the generator varies widely. It depends chiefly on what fuels are easily available and the types of technology that the power company has access to.
a. STEAM TURBINE plants use the pressure generated by expanding steam to turn the blades of a turbine. b. GAS TURBINE plants use the heat from gases to directly operate the turbine. Natural gas fuelled turbine plants can start rapidly and so are used to supply "peak" energy during periods of high demand, though at higher cost than base-loaded plants.
TWO TYPES OF HYDRAULIC TURBINES a) Impulse Type use for high-heads and low volume, example is the Pelton wheel. b) Reaction Type use for low-heads and high volume, examples are Francis and Kaplan.
TYPES OF HYDRO-ELECTRIC PLANT
a) Run-of-river using pondage or steam flow as it occurs, more power can be generated in a rainy season than in dry season. b) Plant with storage capacity associated with a large water reservoir. This permits regulated supply of water so that the power output is constant throughout the year.
3. Diesel Power Plant a plant of internal combustion engine (ICE) prime-mover using diesel as fuel in producing energy. 4. Windmill Plant using a series of windmills as prime-mover.
3. Regulating Plant plant capable of carrying load for the time interval either during off-peak or peak periods and usually responds to changes in system frequency.
4. Reserve or Stand by Plant for peak or system deficiencies.
where : Wnet = Wt - WP
Overall Efficiency (eo)
= e t x eg
HR =
xK
1. Connected Load (CL) it is the sum of all continuous rating of all utilization equipment in the consumer premises connected to the supply system. 2. Maximum Demand (or Peak Load) (MD) it is the greatest demand of load on the power station during a given period. 3. Average Load (AL) the average of loads occurring on the power station in a given period, sometimes called average demand.
4. Demand Factor (DF) it is the ratio of maximum demand on the power station to its connected load.
Div. Factor DF =
L.F. =
8.Capacity Factor (CF) it is the ratio of actual energy produced to the maximum possible energy that could have been produced during a given period.
C.F. = TEP I.C. x P r
9.Nameplate or Capacity Rating is the ability to carry load under conditions specify by the manufacturer.
10. Capability Rating is the maximum output of equipment obtained by test under specific operating condition (not specified by manufacturer)
11. Plant Use (or Output) Factor it is the ratio of the energy generated to the product of plant capacity and the number of hours for which the plant was in operation.
P.U.F =
TEP I.C. x Sr