Upload
sandip-de
View
240
Download
6
Embed Size (px)
Citation preview
8/8/2019 Micro Hydro Testing
http://slidepdf.com/reader/full/micro-hydro-testing 1/6
Fundamental Characteristics of Test Facility for Micro
Hydroelectric Power Generation System
T. Sakurai1, H.Funato
2and S.Ogasawara
3
1 Tomoyuki Sakurai and 2 Hirohito Funato/Utsunomiya University Department of Electrical and Electronic Engineering 7-1-2 Yoto,Utsunomiya, Tochigi, Japan 321-8585
3Ogasawara Satoshi/Hokkaido University Department of System Science and Informatics zyonishi 9-chome kita-ku kita14,
Sapporo, Hokkaido, Japan 060-0814
Abstract-This paper proposes a test facility for micro hydraulic
generation system. Micro hydraulic generation system is very
difficult to exam their characteristics including hydraulic turbine
because water flow in various conditions is necessary but it is very
difficult to realize in laboratory. In this paper water flow is
realized using general purpose pump that can add pressure to
water flow to simulate water drop. From obtained experimentalresults, a simulation model of hydro turbine was built in order to
establish high efficiency control system.
Index Terms - Micro hydroelectric power generation, IPM
synchronous generator, turbine model, MPPT.
I. I NTRODUCTION
Recently global warming becomes big problem. Therefore the
development of the clean energy that does not discharge CO2 is
strongly expected. Micro hydroelectric power generation is one
of the attract choices(1) ~ (4)
. Micro hydraulic power generation is
with small, simple facilities and has stable output. The authors
have studied a new micro hydraulic power generation with
simple mechanism and high efficiency. The proposed system
was tested in a real river (5)(6)
. Micro hydraulic generation system
is very difficult to exam their characteristics including hydraulic
turbine because water flow in various conditions is necessary
but it is very difficult to realize in laboratory. This paper
proposes a new test facility for micro hydraulic generation
system. In this system, a water flow is realized using general
purpose pump that can add pressure to water flow to simulate
water drop. Fundamental characteristics are obtained using the
proposed facility toward high efficiency micro hydraulic
generation system.
II. SYSTEM CONFIGURATION
Outline of the proposed test facility for micro hydroelectric
power generation system is shown in Fig.1. The top right corner
of Fig.1 shows the inside of the generation system box
connected to a hydraulic turbine. Configuration of the test
facility is show in Fig.2. The water tank can save water then the
saved water is drawn in general purpose submersible pump and
supplied to a hydraulic turbine through the hose. Pressure gauge
and flow meter are installed in the upper part at the hose.
Therefore its pressure head and velocity head can be calculated
using measured pressure and flow. A general-purpose
centrifugal pump is used as reversible pump-turbine. The
centrifugal pump is one of the most popular pumps which can
generate pressure by centrifugal force caused by the turn of the
impeller. The exit of the reversible pump-turbine is connected
with the hose to a water tank. The provided machine energy by ahydraulic turbine is sent to an IPM synchronous generator
through the shaft then electric power is generated. A torque
meter is installed between a hydraulic turbine and IPM
synchronous generator so that efficiency of hydraulic turbine
and IPM synchronous generator can be measured separately.
Ratings of the centrifugal pump used as a hydraulic turbine and
the rating of IPM synchronous generator as motor operation is
shown in table 1.
The electric connection of micro hydroelectric power
generation system is shown in Fig.3. A general-purpose inverter
drives submersible pump and a diode rectifier is connected to dc
bus to establish the bus voltage. A PWM rectifier is connected to
IPM synchronous generator. Because it is difficulty to make a
big effective head physically in experiments, the water pump
with variable pump speed with inverter can raise pressure and
give effective head equivalently. A PWM rectifier is used to
realize variable-speed operation of the IPM synchronous
generator and load is connected to the dc bus. Because the
generated power is not controlled in the experimental system, a
diode rectifier is connected in parallel to resistive load. The
diode rectifier supplies the difference between load power and
generated power. Therefore in case of no generation power, the
load power is supplied entirely by the diode rectifier. Then the
increase of generated power cause decrease of supply power
from diode rectifier. The generated power is measured by thedigital power meter inserted between the IPM synchronous
generator and PWM rectifier. The controller is composed of
FPGA (Field Programmable Gate Array) combined with CPU
core so that position–sensor less control and maximum power
tracking control can be implemented in the near future(6) (7)
.
III. EXPERIMENT RESULT
As shown in Fig.2, effective head is equivalently realized by
pressurized water flow made by submersible pump with
8/8/2019 Micro Hydro Testing
http://slidepdf.com/reader/full/micro-hydro-testing 2/6
Fig.1. Outline of the micro hydroelectric power generation system.
Fig.2. Configuration of the test facility micro hydroelectric power generation
system.
TABLE I
RATIONS OF HYDRAULIC TURBINE AND GENERATOR
Fig.3. Electric connection.
adjustable speed. Frequency of submersible pump can be
regulated from 0 to 50Hz. The height from the hose of the upper
part duct to a hydraulic turbine is 1.41m as shown in Fig.2. This
becomes potential head h. Pressure head h p and velocity head hv
can calculate from pressure P and flow Q measured with a
pressure gauge and the flow meter in the hose. h la is the loss of
head of the hose from a submersible pump to a pressure gauge. It
can be calculate from shape of the hose and the water flow of the
hose. Total head H of the whole system is
H = h + h p+ hv + hla. (1)
The head at the hydraulic turbine input becomes
H t = h + h p + hv − hlb. (2)
hl b is the head of loss of the hose from a pressure gauge to ahydraulic turbine. The water flowing into the hydraulic turbine
turns the runner anticlockwise direction seeing from the
generator side and generates electricity. Because IPM
synchronous generator is operated by simple V/f control, speed
of IPM synchronous generator and hydraulic turbine is decided
by PWM rectifier frequency. Because IPM synchronous
generator has 6 poles and the frequency of the PWM rectifier
can be regulated input from 0 to 50Hz, this means revolving
speed can be controlled from 0 to 1,000 rpm.
The relationship between water flow Q and revolving speed of
submersible pump under fixed generator frequency f g is shown
in Fig.4. Fig.4 (a) shows pressure P and (b) shows total head H .
Total head H is calculated from Eq. (1). From Fig.4, it is clear
that increase of revolving speed of submersible pump causes
increase of water flow and pressure. This results in increase of
total head. In Fig.(4) (a), when water flow Q is 200l/min, the
higher the generator frequency become, the bigger the resistance
of hydraulic turbine becomes. On the other hand, when water
flow Q is almost 500l/min, the resistance of the hydraulic
turbine at f g of 10Hz is higher than that at f g of 40Hz. In Fig.(4)
(b), the shape of curve is quite similar to that in Fig.4 (a) so that
it is clear that total head depends on pressure head.
The ratio of each head for total head at f g of 20Hz are shown in
Fig.5. The increase of revolving speed causes the increase of
total head. As mentioned previously, the increase of total head iscaused by increase of pressure. From Fig.5, it is clear that the
higher the total head becomes, the smaller the ratio of potential
head becomes and the bigger the ratio of pressure head becomes
because potential head is constant. The ratio of velocity head is
very small (less than 2%) so that the velocity head will be
ignored in the following of this paper.
Characteristics of hydraulic turbine in case of fixed generator
frequency f g ( f g =10, 20, 30, 40, 50Hz) are shown in Fig.6. The
horizontal axis is the head H t . The left vertical axis is power and
the right vertical axis is efficiency. The hydraulic turbine input
power P i, hydraulic turbine output power P t and hydraulic
turbine efficiency η t = P t P i are plotted in each graph. Hydraulicturbine input power P i is calculated by P i= 9.8QH t . In the
following, “head” means hydraulic turbine input head H t .
Hydraulic turbine output power P t is calculated by the product of
revolving speed and toque measured by toque meter. From
experimental results, it is clear that input and output power of
hydraulic turbine increase linearly. The characteristics of
hydraulic turbine efficiency change depending on frequency as
shown in Fig.6. From Fig.6(a), (b) and (c) maximum efficiency
point can be observed at 2.3m of the head at 10Hz of f g , 2.2m of
the head at 20Hz of f g and 4.1m of the head at 30Hz of f g
discharge 0.5 m3/min rated power as motor operation 1.5 kW
total head 12.7 m frequency 72.5 Hz
water power 1.85 kW poles 6
pump eff. 55 %
IPM synchronous generator hydraulic turbine
pressure gauge
submersible
pump
flow meter
torque
meter
hydraulic
turbine
water hose
water tank
hydraulic
turbine
IPM
synchronous
generator
pressure gauge flow meter
water tank
submersible pump IPM synchronous generator
torque meter
hydraulic turbine
water hose: water flow
shaft 1.2 m
pressure gauge flow meter
water tank
submersible pump IPM synchronous generator
torque meter
hydraulic turbine
water hose: water flow: water flow
shaft 1.2 m
IPMSG
power
meter
Inv.
PWM
Rec.Load
submersible pump hydraulic turbine
IPMSG
power
meter
Inv.
PWM
Rec.Load
submersible pump hydraulic turbine
8/8/2019 Micro Hydro Testing
http://slidepdf.com/reader/full/micro-hydro-testing 3/6
0.00
2.00
4.00
6.00
8.00
10.00
12.00
0 100 200 300 400 500 600
flow Q [l/min]
t o t a l h e a d H [ m ]
fg=50Hz
fg=40Hz
fg=30Hz
fg=20Hz
fg=10Hz
0%
20%
40%
60%
80%
100%
1.24 2.09 3.26 4.64 6.11 7.80 9.38total head H [m]
loss of head [m]
velocity
head [m] pressure
head [m]
potential
head [m]
(a) pressure VS. flow
(b) total head VS. flow
Fig.4. Flow characteristic (constant generator frequency)
Fig.5. Ratio of each head (generator frequency f g = 20 Hz)
respectively. In case of Fig.6(d) and (e), maximum efficiency
point can not be observed because there may be at the higher head. From Fig.6(d), the output power of 402W is obtained at
the head of 9.25m.
Characteristics of generator in case of fixed generator
frequency f g ( f g =10, 20, 30, 40, 50Hz) are shown in Fig.7. The
horizontal axis is the head H t . The left vertical axis is power and
efficiency. The generator input power (= hydraulic turbine
output power P t ), the output power P g and efficiency η g = P g /P t
are plotted in each graph. The generator power is measured by
digital power meter. In the case when the generator power is
negative in Fig.7(a), the generator loss is not covered by
hydraulic turbine input power so that part of loss power is
supplied from PWM rectifier. The generator efficiency is
calculated only when the generator output power becomes
positive. From Fig.7, generator input power and output power
increase approximately linearly. In case of Fig.7(a), the
generator output power becomes negative to all head region so
that it is impossible to get electric power. From Figs.7(b), (c),
(d) and (e), generator efficiency increases according to theincrease of the head. From Fig.7(d), the maximum generator
efficiency of 76% and more then 300W generator output power
are obtained. In these experiments, the generator efficiency is
lower than its maximum efficiency because the voltage
coefficient of V/f control was not optimized. Therefore the
generator efficiency may be improved if optimized coefficient is
employed.
Each power and efficiency of hydraulic turbine and generator
for fixed generator frequency f g are shown in Fig.8. These
curves are calculated from Fig.6 and 7. The horizontal axes are
the head H t . Fig.8(a) shows the hydraulic turbine output power
P t , (b) shows the generator output power P g , (c) shows the
hydraulic turbine efficiency η t and (d) shows the generator efficiency η g . From Fig.8(a), it clear that the slope of the
hydraulic turbine output power depends on generator frequency.
This result in the optimum operation frequency should be
selected to get the maximum output power from hydraulic
turbine at a certain head. In Fig.8(b) the similar result was
obtained because generator output power depends on turbine
output power. From Fig.8(c), it is observed that each operation
speed has optimum head to get maximum efficiency of
hydraulic turbine. In Fig.8(d), the higher the head becomes, the
more the efficiency improved.
Each power and efficiency of hydraulic turbine and generator
for fixed head are shown in Fig.9. The horizontal axis is thegenerator frequency f g . Fig.9(a) shows hydraulic turbine output
power P t , (b) shows generator output power P g , (c) shows
hydraulic turbine efficiency η t and (d) shows generator
efficiency η g respectively. Because it is difficult to make
experiments at fixed head, Fig.9 is obtained from Fig.8 to
observe power and efficiency at certain head. From Fig.9(a),
when the head is over 3m, there is the optimum frequency to get
maximum turbine output power. The higher the head becomes,
the higher the optimum frequency is. Similar result can be
observed for IPM generator output power from Fig.9(b). From
Fig.9(c), the optimum generator frequencies f g to get maximum
hydraulic turbine efficiency become 24Hz, 30Hz, 37 Hz and
42Hz for the heads of 3m, 5m, 7m and 9m respectively. From
Fig.9(d), the optimum generator frequencies f g to get maximum
generator become 30Hz and 40Hz for the heads of 5m and 7m
respectively.
IV. SIMULATION MODEL OF HYDRO TURBINE FOR MXIMUM
EFFICIENCY
From obtained result, a simulation model of hydro turbine can
be built in order to establish maximum efficiency control. Using
established simulations, the control algorithm can be considered
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0 100 200 300 400 500 600
flow Q [l/min]
p r e s s u r e P [ M P a
fg=50Hz
fg=40Hz
fg=30Hz
fg=20Hz
fg=10Hz
8/8/2019 Micro Hydro Testing
http://slidepdf.com/reader/full/micro-hydro-testing 4/6
-100
0
10 0
20 0
30 0
40 0
50 0
60 0
70 0
80 0
90 0
0.00 2.00 4.0 0 6.00 8.0 0 10.00
turbine input head H t [m ]
t u r b i n e i n p u t - o u t p u t p o w e r [ W ]
0
0. 1
0. 2
0. 3
0. 4
0. 5
0. 6
t u r b i n e e f f i c i e n c y
P i
P t
η t
turbine input power Pturbine output power Pturbine efficiency
turbine input power P i
turbine output power P t
turbine efficiency η t
turbine input power Pturbine output power Pturbine efficiency
turbine input power P i
turbine output power P t
turbine efficiency η t
t u r b i n e e f f i c i e n c y
t u r b i n e i n p u t - o u t p u t p o w e r [ W ]
-100
0
10 0
20 0
30 0
40 0
50 0
60 0
70 0
80 0
90 0
0.00 2.00 4 .00 6.00 8.0 0 10 .00
turbine input head H t [m ]
t u r b i n e i n p u t - o u t p u t p o w e r [ W ]
0
0. 1
0. 2
0. 3
0. 4
0. 5
0. 6
t u r b i n e e f f i c i e n c y
P i
P t
η t
t u r b i n e i n p u t - o u t p u t p o w e r [ W ]
t u r b i n e e f f i c i e n c y
-100
0
10 0
20 0
30 0
40 0
50 0
60 0
70 0
80 0
90 0
0 .00 2.00 4.0 0 6.00 8.00 10.00
turbine input head H t [m ]
t u r b i n e i n p u t - o u t p u t p o w e r [ W ]
0
0 .1
0 .2
0 .3
0 .4
0 .5
0 .6
t u r b i n e e f f i c i e n c y
P i
P t
η t
t u r b i n e i n p u t - o u t p u t p o w e r [ W ]
t u r b i n e e f f i c i e n c y
-100
0
10 0
20 0
30 0
40 0
50 0
60 070 0
80 0
90 0
0.00 2.00 4.0 0 6.00 8.0 0 10 .00
turbine input head H t [m ]
t u r b i n e i n p u t - o u t p u t p o w e r [ W ]
0
0. 1
0. 2
0. 3
0. 4
0. 5
0. 6
t u r b i n e e f f i c i e n c y
P i
P t
η t
t u r b i n e i n p u t - o u t p u t p o w e r [ W ]
t u r b i n e e f f i c i e n c y
-100
0
10 0
20 0
30 0
40 050 0
60 0
70 0
80 0
90 0
0.00 2.00 4 .00 6.00 8 .00 10 .00
turbine input head H t [m ]
t u r b i n e i n p u t - o u t p u
t p o w e r [ W ]
0
0. 1
0. 2
0. 3
0. 4
0. 5
0. 6
t u r b i n e e f f i c
i e n c y
P i
P t
η t
t u r b i n e i n p u t - o u t p u t p o w e r [ W ]
t u r b i n e e f f i c i e n c y
-200
-100
0
10 0
20 0
30 0
40 0
50 0
0.00 2 .00 4.0 0 6 .00 8 .00 10 .00
turbine input head H t [m ]
g e n e r a t o r i n p u t - o u t p u t p o w e r [ W ]
P g
P t
generator input power P t
generator output power P g
generator eff iciency η g
generator input power P t
generator output power P g
generator eff iciency η g
g e n e r a t o r i n p u t - o u t p u t p o w e r [ W ]
-200
-100
0
10 0
20 0
30 0
40 0
50 0
0.0 0 2 .00 4.00 6.00 8 .00 1 0 .00
turbine input head H t [m ]
g e n e r a t o r i n p u t - o u t p u t p o w e
[ W ]
0
0. 1
0. 2
0. 3
0. 4
0. 5
0. 6
0. 7
0. 8
g e n e r a t o r e f f i c i e n c
η gP g
P t
g e n e r a t o r i n p u t - o u t p u t p o w e r [ W ]
g e n e r a t o r e f f i c i e n c y
-200
-100
0
10 0
20 0
30 0
40 0
50 0
0.0 0 2 .00 4.00 6.00 8.0 0 1 0.0 0
turbine input head H t [m ]
g e n e r a t o r i n p u t - o u t p u t p o w e r
[ W ]
0
0. 1
0. 2
0. 3
0. 4
0. 5
0. 6
0. 7
0. 8
g e n e r a t o r e f f i c i e n cg
P g
P t
g e n e r a t o r i n p u t - o u t p u t p o w e r [ W ]
g e n e r a t o r e f f i c i e n c y
-200
-100
0
10 0
20 0
30 0
40 0
50 0
0.00 2 .00 4.00 6.00 8.0 0 1 0.0 0
turbine input head H t [m ]
g e n e r a t o r i n p u t - o u t p u t p o w e
[ W ]
0
0. 1
0. 2
0. 3
0. 4
0. 5
0. 6
0. 7
0. 8
g e n e r a t o r e f f i c i e n c yη g
P g
P t
g e n e r a t o r i n p u t - o u t p u t p o w e r [ W ]
g e n e r a t o r e f f i c i e n c y
-200
-100
0
100
200
300
400
500
0.00 2.00 4.00 6.00 8.00 10.00
turbine input head Ht [m]
g e n e r a t o r i n p u t -
o u t p u t
p o w e r [ W
]
0
0.1
0.2
0.3
0.40.5
0.6
0.7
0.8
g e n e r a t o r e f f i c i e n c yg
P g
P t
g e n e r a t o r i n p u t - o u t p u t p o w e r [ W ]
g e n e r a t o r e f f i c i e n c y
(a) generator frequency f g = 10 Hz
(b) generator frequency f g = 20 Hz
(c) generator frequency f g = 30 Hz
(d) generator frequency f g = 40 Hz
(e) generator frequency f g = 50 Hz Fig.6. Characteristic of hydraulic turbine.
(a) generator frequency f g = 10 Hz
(b) generator frequency f g = 20 Hz
(c) generator frequency f g = 30 Hz
(d) generator frequency f g = 40 Hz
(e) generator frequency f g = 50 Hz Fig.7. Characteristic of generator.
8/8/2019 Micro Hydro Testing
http://slidepdf.com/reader/full/micro-hydro-testing 5/6
8/8/2019 Micro Hydro Testing
http://slidepdf.com/reader/full/micro-hydro-testing 6/6
and testes, then the result can be feedback to experiments to
verify the obtained algorithm. One example of simulation of
PSIM is shown in Fig.10 which is same configuration to
experimental system. The hydro turbine model is composed of a
look-up table which has two inputs (water flow and speed of
generator) and one output (torque) and external control load
with inertia. Using this simulation model, the maximum
efficiency control will be considered.
V. CONCLUSIONS
This paper proposes a new test facility for micro hydraulic
generation system and to get fundamental characteristics. In the
examinations, characteristics of the hydraulic turbine and
generator are measured by several effective head equivalentlyrealized by submersible pump to adjust revolving speed. Output
power of 402W and maximum efficiency of 51% are obtained
for hydraulic turbine. Output power of over 300W and
maximum efficiency of 76% are obtained for generator. From
obtained experimental results, a simulation model of hydro
turbine was built. Using this simulation model, the maximum
efficiency control will be considered. This work was partially
supported by Grant-in-Aid for Scientific Research (c)
(KAKENHI) provided by Japan Society for the Promotion of
Science.
R EFERENCES
[1] T. Kikuchi R. Ozawa, J. Itsumi, and H. Tajima: "Reserch of micro
hydraulic power generation",2001 National Convention Record, IEE
Japan,Vol.7, pp.3099(2001-3)
[2] T. Mori, K. Itako, and T. Kimura: "Practical Use of small Scale(about 1kW
)Hydroelectric Power Generation in Consideration of Environment",2002
National Convention Record, IEE Japan,Vol.7, pp.134(2002-3).
[3] Y. Kainuma, K. Yukita, Y. Goto, and K. Ichiyanagi: "A Basic Study of
Micro Generator by changing Number of Poles", 2006 National
Convention Record, IEE Japan,Vol.6, pp.32(2006-3)
[4] C. Marinescu, L. Clotea, M. Cirstea, I. Serban, C. Ion: "CONTROLLINGVARIABLE LOAD STAND-ALONE HYDROGENERATORS",
IECON, pp.2554-2559 (2005)
[5] S. Ogasawara, H. Funato, H. Takakamo, K. Kunio, K. Kazuo, T. Kobayasi:"Fundamental Experiment of a Micro Hydroelectric Power Generation
System Using an IPM Synchronous Generator", IEEJ-IAS Technical
Meeting on Semiconductor Power Converter, SPC-07-59(2007) [6] T. Sakurai, H. Funato, S. Ogasawara, K. Kunio, K. Kazuo, T.
Kobayasi:"Fundamental Experiment of a Siphon Type MicroHydroelectric Power Generation System Using an IPM Synchronous
Generator", IEEJ-IAS Technical Meeting on Semiconductor Power
Converter, SPC-08-84(2008)
[7] H. Takada and S. Ogasawara: "A Position-Sensorless IPM Motor Drive
System Using Field Prgramble Gate Array With CPU Core", IEEJ-IAS
Technical Meeting on Semiconductor Power Converter, SPC-04-28(2004
)
hydro turbine model
Fig.10. One example of simulation