MICRO HYDROELECTRIC POWER
PLANT WITH CHAIN TURBINE
Nguyen Minh Duy
Content
1.
2.
3.
4.
Overview about hydroelectric power plant
Analysis chain turbine
Governor using for chain turbine
Work in the future
Hydropower to Electric Power
Potential
Energy
Electrical
Energy
Electricity
Kinetic
Energy
Mechanical
Energy
Hydropower to Electric Power
How Hydropower Works



Water from the reservoir
flows due to gravity to
drive the turbine.
Turbine is connected to a
generator.
Power generated is
transmitted over power
lines.
How Hydropower Works (2)



A water turbine that cover the energy of flowing
or falling water into mechanical energy that
drives a generator, which generates electrical
power. This is a heart of hydropower power plant.
A control mechanism to provide stable electrical
power. It is called governor.
Electrical transmission line to deliver the power
to its destination.
Vietnam Hydroelectric Potential
Vietnam Hydroelectric Potential (2)



Vietnam, the nation yearly average of rainfall is
about 1,861mm.
There are more than 2,200 big-to-small rivers
and streams. So Vietnam is rich hydropower
resource.
Vietnam is agricultural country (agriculture:
20.1%). This is a goal to invest SHP.
Sizes of Hydropower Plants






Pico hydroelectric plant
 Up to 10kW, remote areas away from the grid
Micro hydroelectric plant
 Capacity 10kW to 300kW, usually provided power
for small community or rural industry in remote
areas away from the grid
Small hydroelectric plant
 Capacity 300kW to 1MW
Mini hydroelectric plant
 Capacity above 1MW
Medium hydroelectric plant
 15 - 100 MW usually feeding a grid
Large hydroelectric plant
 More than 100 MW feeding into a large electricity
grid
Micro Hydropower Systems
Many creeks and rivers are permanent,
they never dry up, and these are the most
suitable for micro-hydro power production
 Micro hydro turbine could be a waterwheel
 Newer turbines : Pelton wheel (most
common)
 Others : Turgo, Crossflow and various
axial flow turbines

Turbine Classified
Impulse Turbines
Uses the velocity of the water to move the
runner and discharges to atmospheric
pressure.
 The water stream hits each bucket on the
runner.
 High head, low flow applications.
 Types : Pelton turbine, Turgo turbine

Pelton Turbine
Turgo Turbine
Reaction Turbines
Combined action of pressure and moving
water.
 Runner placed directly in the water stream
flowing over the blades rather than striking
each individually.
 Lower head and higher flows than
compared with the impulse turbines.

Francis Turbine
Kaplan Turbine
Turbine Selection Chart
Chain Turbine




It is a gravity machine
It is built up of two
parallel chain systems
joint together at the
chains with a series of
buckets.
The flow rater entering
the buckets is controlled
by the water valve
through a motor to open
or close the valve.
Buckets fill full of water
go down to bring to rotary
sprocket system.
Analysis of the Chain Turbine


With flow rate is
1m3/s, and the head is
20m.
Assume H1=19m,
H2=1m, the diameter
of the sprocket is 1m.
Analysis of the Chain Turbine (2)

The gross power output:
Pgross  QgH gross  1000 1 9.81 20  196kW

Apply the principle of work and energy with the bucket of chain
turbine:
1
1
mgh0  mv02  mght  mvt2
2
2

The maximum speed of bucket
vt  2gH1
The angular velocity the sprocket would be
v
9.75
  op 
 19.5rad / sec
R
0.5

The rotational speed of the sprocket would be

rpm 
  60 9.4  60

 186.2  186rpm
2
2
Analysis of the Chain Turbine (3)

Number of buckets in chain turbine
(2 H1  D)Q 4.02
N

vopQ1
Q1
Number of
buckets
The volume of a
bucket (m3)
8
0.50
10
0.40
12
0.36
Analysis of the Chain Turbine (4)

The power output is
2
Pout  T  Qvopr  Qvop

The power out of the turbine shaft
2
Pout  Qvop
 1000 1 9.752  95.1kW

The efficiency of the chain turbine is given by

Pout
95.1kW

 0.49
Pgross 196kW
Analysis of the Chain Turbine (5)
Rotational velocity of sprocket depends on
the distance of between two shafts of
turbine H1.
 Rotational velocity of turbine shaft is slow,
so it cannot directly connect with
generator. It need a power transmission
 Efficiency of chain turbine is low.

Advantages of Chain Turbine
It is run-of-river power plant.
 Do not worry about the turbidity of water.
 There is no danger of cavitations.
 It is simple to construct, repaired and
maintenance.

Disadvantages of Chain Turbine
 The
slow rotation of chain turbine leads to
high speed ratios when connect to generator
at 600 rpm – 1500 rpm.
 This chain turbine operation is very noise.
 Structure of turbine is very big
Governor
 To maintain the generator at a constant 50Hz
frequency, it is necessary to maintain the generator
shaft at a constant rotational speed.
 In the independent hydroelectric power plant, the
rotational speed of the micro hydro power generator
can be change when loads are added or subtracted
from the electrical system.
N0  p
f 
120
Governor (2)




The system frequency can be maintained constant by eliminating the
mismatch between generator and load.
Governor is to receipt the frequency signal from the output of generator.
And it is compared with standard frequency signal.
From these results, governor output signal is coming-out to control the
valve of water at the entrance to the turbine.
Transfer Function Block Diagram of Hydro Plant

KP

TW

K IS

K PS
power system gain constant (Hz/p.u)
nominal starting time of water in penstock (s)
integral gain constant for servo system
proportional gain controller constant for servo motor
Governor Transfer Function

Chain Turbine transfer function
 Tw

water starting time at full load
Pm
1  Tw s

G 1  0.5Tw s
Tw 
So transfer function of chain turbine is
LU r 1  2  g  1

 0.022s
gH
9.81  20
Pm
1  Tw s
1  0.022 s


G 1  0.5Tw s 1  0.011s
Generator Transfer Function



Assume nominal load PL  90kW
Frequency 50Hz
The latter load assumption yields
D

PL
90kW

 0.018 p.u / Hz
fPR 50 Hz  100kW
So, the system gain constant and time constant are given by
1
K P   55.55Hz / p.u
D
TP 

2H
2 1

 2.22s
fD 50  0.018
The transfer function of generator
G p (S ) 
Kp
1  sT p

55.55
1  2.22 s
Transient responses of system for step changes
in load, showing deviations in system frequency
Transient responses of system for step changes in load,
(1.5kW) for different integral gain value, showing
deviations in system frequency (1)
Transient responses of system for step changes in load,
(1.5kW) for different integral gain value, showing
deviations in system frequency (2)
Transient responses of system for step changes in load,
(1.5kW) for different integral gain value, showing
deviations in system frequency (1)
Transient responses of system for step changes in load,
(1.5kW) for different integral gain value, showing
deviations in system frequency (2)
Governor Discussion
It is more flexible than classical governor.
 This governor effectively eliminate the
frequency deviations due to load
disturbances for different nominal
loadings of the system
 It is importance as the saved water can
be used for irrigation.

Work in the Future


In China, YiuHwa Engineering Company is building a hydroelectric
power plant with chain turbine to experiment and research with
capacity 200kW.
This plant has two turbines and built with head 20m and flow rate
1.03m3/sec