Hydel Power

Hydro Electric Power  ( Hydel Power )

When the blades of turbines is turned and water flow through the turbine which is connected by shaft of the generator then hydro electric power is generated

Complete mechanism of Hydro Power(turbine coupled with generator)

Main component:

There are following like Dam, Reservoir, Large buffer tank, Penstock and Power houses are the main component of the Hydro Electric generation. In the Powerhouse Turbines, Generators, Step Up Transformer and different complicated circuits for protection and safety of high power generators are used.

Categories:

Large Hydel Plant:

50MW to 1000 MW(Large Cities)

Small Hydel Plant:

1 MW to 50MW (Small Cities)

Mini Hydel Plant:

100kW to 1000KW(Towns)

Micro Hydel Plant:

< 100kW(Rural Community)

Pico Hydel Plant:

<5KW (Individual Home)

Efficiency

The efficiency of plant can be calculated by following formula.

Power _ Delivered = 7. H. dQ/dt = Kilowatts

H = head in meter

DQ/dt = rate of discharge in m³/sNormally hydel plant efficiency id about 75%.

Types of Generator

Ø Permanent magnet DC generator (PMDC)

Ø Alternator (Synchronous Generator)       

Ø Induction Generator

Ø Synchronous reluctance Generator

There are the following important point: 

Ø  Sinusoidal output

Ø  Good voltage regulation

Ø  Rugged and easy to maintain

Ø  Simple to fabricate

Ø  High efficiency 

Ø  Cost effective for given power

Ø  Ease of servicing/operation

Ø  Safety

Ø  Reliability

Which one is Best: 

Among of all the Induction generator is batter w.r.t. others but with poor voltage regulation. Voltage regulation is improved simply by using governors in parallel to the actual load.

Water energy:

Lots of energy in the water no one bear the  water energy (in flood season). Human can use this energy by his benefits to build the hydro plant. In the hydro plant energy of water enhance which depends upon two factors. Ø  Head

 Ø  Flow

The head is vertically high and large to increase the flow of water through  turbine for maximum output.
The flow is the amount of water that’s flows in one second.

                   Energy = m.g.h

m = mass of water = Kg
g = acceleration due to gravity = 9.81 m/s²
h = height = meter

                           Energy = ρ. Q. g. h joules

ρ = density of water = Kg/m³
Q = discharge = m3
g = acceleration due to gravity = 9.81 m/s²
h = height = meter

                          Power = ρ. dQ/dt. g. h joules

ρ = density of water = Kg/m³
dQ /dt = rate of discharge = m³/s
g = acceleration due to gravity = 9.81 m/s2
h = height = meter
1 Kilowatt-Hour = 1000 watts x 3600 seconds = 3.6e⁶
watt-second = 3.6e⁶ Joules
1 m³ = 1000 liters
Let the efficiency of hydro power is 70 to 75%.

                        Power _ Delivered = 7. H. dQ/dt = Kilo watts

h = Head in meters
dQ/dt = Rate of discharge in m3/s.

Turbine:

Turbine is the one of the most important part for generating the electricity from hydro power. Its like a machine that’s converts the potential energy of water into the mechanical energy. As the time pass different types of turbine are formed for different criteria.

Ø  Impulse turbines for high heads.Ø  Reaction turbines for low heads.Ø  Submersible propeller turbines.
Some of the turbines are Elton, crossflow, turbo, Francis, Harris
etc.

Generator:

Induction and synchronous generators are used in the power houses to generate electricity. Induction generators are more reliable for far areas. The 3 phase induction motor can be used as a generator.

In some application the use to synchronous and dc generator are very pro-motive.

  

Load Control:
Control the load is one of the most and complicated phenomena e.g when load increase suddenly effect the generator and the vibration of the shaft of the generator increase more chances to break the baring of the turbine which is to expensive. We control the load or fill full the demand the require load by increase the water flow from wicket gates and change the angle of fans of the turbine. The opening of wicket gates and changing of fan’s angle controlled by governor with the most efficient combination.

In the power houses deals with MW power so the controlling of load is done by most  complicated electronic circuit’s and monitored by experts.

Changing of load mean disturb the speed which also effect the voltage and frequency.

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