Energy and Power Engineering, 2013, 5, 63-67
doi:10.4236/epe.2013.54B012 Published Online July 2013 (
Analysis and Application of Hydropower Real-time
Performance Calculation
Dequn Feng1, Zhiwei Wang2, Pengbo Ma2, Wenqing Wang2
1Xi’an Electric Power College, Xi’an, China
2Xi’an Thermal Power Research Institute, Xi’an, China
Received March, 2013
The hydropower running and performance can be displayed and analyzed by the real-time remote system. Real-time
performance data of the hydraulic turbine unit can be obtained through the analysis of real-time operating data of the
hydraulic turbine unit. It can not only guide significance for long-term operation of hydraulic turbine unit, but also pro-
vide a reference for improving the Hydropower hydro efficiency, economic dispatch of hydraulic turbine unit and per-
formance comparison before and after the overhaul.
Keywords: Hydropower Units; Performance Analysis; Efficiency
1. Introduction
Same type of hydraulic turbines could have different
turbine efficiency due to different design and manufac-
turing level or defects caused during production or in-
stallation process. It is quite important to manage to
make full use of water resources and improve the ec
nomic performance of hydropower station by under-
standing the actual running efficiency of hydraulic tur-
bines and avoiding turbine operation at low efficiency
2. Power Plants Production Real-time
Monitoring System
A power plant or power generation group production real
time monitoring system (hereinafter referred to as the
system) the realization of the data acquisition, real-time
transmission site, centralized storage and hydroelectric
station of on-line performance calculation and analysis
For power plants or electricity power generation groups,
the production real-time monitoring system (hereafter
referred as System) realizes the on-site data collection
and real-time transmission, as well as the centralized data
storage and online performance calculation and analysis
of hydropower stations[1].
To ensure the accuracy and reliability of the real-time
performance calculation, raw data to be collected from
the control system in hydropower stations directly. Based
on IEC60870-5-101 or IEC60870-5-104 standard proto-
col, instant data is collected from the designated measur-
ing points of the control system[2].
Data collection needs to consider the following: must
ensure that data is collected in time accuracy of seconds;
data to be buffered and stored locally in case of lack of
transmission bandwidth or interruption caused by any
abnormal condition, and the data must be loaded back
automatically upon network link restoration.
3. Calculation of the Performance of
Hydropower Stations
Lots of problems could incur to apply the performance
data of the model machine on a prototype, as the opera-
tion characteristic curve of the hydraulic turbines is cal-
culated based on the experimental model machine, where
the prototype differs from the model machine in many
ways, such as installation precision, the scale effect be-
tween the two, quality differences of the turbines (espe-
cially rotations) from manufacturing and so on. The tur-
bine performance calculation in accordance with the
"GB/T 20043-2005 Field acceptance is tested to deter-
mine the hydraulic performance of hydraulic turbine,
storage pumps and pump-turbine"[3].
Normally the long-term and instant performance mon-
itoring is unable to be achieved as the turbine operation
efficiency test is typically carried out after performance
defects appear or upon overhaul.
Under the guidance of "DL/T 262-2012 thermal power
unit coal consumption online guide to the calculation of"
and in accordance with GB/T 20043-2005 standard, real-
time calculation of the performance of hydropower sta-
tions can be achieved[4]. The performance of hydraulic
turbines is calculated online: first calculate out the main
Copyright © 2013 SciRes. EPE
economic index of the hydropower station based on
real-time running data, and then, by applying the histori-
cal data, the curve of the economic indicators of the hy-
draulic turbines are produced. The numbers and installa-
tion positions of measuring points required to calculate
the performance are determined based on the analysis of
the site condition. The System accomplishes the online
performance calculation of hydraulic turbines, and the
analysis results can be used as the basis of judgment and
decision making over the real-time economic situation
for power plants.
3.1. Hydraulic Turbines’ Stage Efficiency of
Calculation Principle
Hydraulic turbines’ stage efficiency is the ratio between
turbine shaft power and water power. Considering the
difficulty in measuring the turbine shaft power, the effi-
ciency of the hydraulic turbine units can be calculated
out by applying the same method as that in the prototype
efficiency experiment, and then the efficiency of hydrau-
lic turbines can be produced by converting and calculat-
ing the characteristic efficiency curve of the turbine
power generator.
Hydraulic turbine unit efficiency is defined as follows
slj st
100 QgH
 (1)
Hydraulic turbine efficiency is described as
100 /
lj fdj
slj st
 (2)
Hydraulic Turbine power generation water consump-
tion is defined as
Ne—A generator output power, MW;
NTO—Hydraulic turbines’ input power, MW;
ŋg—Generator efficiency, %;
ηslju—The efficiency of the Hydraulic turbine units, %;
ηslj—hydraulic turbine efficiency, %;
bsljt—hydraulic Turbine power generation water con-
sumption, kg/(Kwh)
Ne—Power generation active power, MW;
Qslj—Hydraulic Turbine water flow, m3/s;
ρ—Over the water density, kg/m3;
g—Acceleration of gravity, 9.8066, m/s2;
Hst—Working head, m
3.2. Data Processing
Based on the actual situation of hydropower stations,
parameters to be collected for on-line calculation include:
output power of the power generator, water flow rate
passing through, working head of the turbine and so on;
Parameters that are not able to be collected on-line such
as the acceleration of gravity, water density, the effi-
ciency of the power generator etc. can be applied based
on pre-defined value from design, and can then be de-
termined by evaluating their effects according to formula
(1) ~ (3) and processed at final stage where the calcula-
tion result is corrected eventually.
It is recommended that the real-time data be taken at
the last 2 minutes average value (taking into account of
any data mismatch and/or fluctuations) and the data
real-time rationality verification be adopted, so as to
avoid input the calculation module any abnormal data
caused by poor communication or bad data collection.
The actual data verification methods vary by the charac-
teristics of parameters. Whenever a key data is replaced,
data is to be screened and filtered to avoid any potential
impact on the result. The way of data screening and fil-
tering should be carried according to the actual calcula-
tion method, effect of parameters, background profes-
sional knowledge etc. The calculation to be done against
the actual situation, avoiding un-representative results
due to poor data stability caused by low workload, start
and stop operation and so on.
3.3. On-line Cal cu l a ti o n S o f tw a r e
On-line calculation should adopt the approach making
use of modular software tools capable of on-line calcula-
tions. This software tools is required to be able to con-
figure the reasonable calculation frequency flexibly, with
easy and quick ways of achieving calculation method,
capable of measuring the irrational cases inside the ma-
thematical logic, diversified logical determination and
rich mathematical processing function, reversing back
calculations where necessary, stable and reliable running,
and with the ability to control strictly the data reading
time and time sequence during calculation.
4. Engineering Applications
The System operates at one hydropower station in Xinji-
ang: the power station was designed to adopt runoff type
turbines that intake water. Having the fall of 218.5 m, it
was developed in 2 stages. The biggest water head of the
turbine in the first stage is 105.8 m by design and rated at
100.8 m, while the smallest water head was designed as
100.7 m, with rated flow at 34.65 m3/s; the biggest water
head in the second stage was designed as 102.2 m, rated
at 100.8 m, and the smallest one is 100.7 m.
Production real-time monitoring system realizes in-
stant data remote acquisition and online calculation of
the hydropower main index[5]. The running and eco-
nomic situation of the unit can be monitored by operation
Copyright © 2013 SciRes. EPE
Copyright © 2013 SciRes. EPE
and management staff at real time[6]. station, the System processes key parameters and displays
on screen the running status in real time. Display is rendered
based on the actual situation on site, in the way varies by
specific interested parameters, as shown in Figures 1-4.
4.1. Real-time Performance Display
With regard to the physical layout of the hydropower
Figure 1. Hydropower run-time performance of the screen.
Figure 2. Hydropower run-time system.
Figure 3. The a station forebay run screen.
Figure 4. Power generation load and hydroelectric generating efficiency curve.
4.2. Unit Performance Comparison
The System calculates performance data of the hydraulic
power station such as the efficiency of hydraulic turbines,
turbine units, water consumption for power generation
etc. The efficiency and relevant parameters of the turbine
units in the second stage is analyzed for the workload
between 30~31MW and 27 MW.
Analyzing the historical data, it indicates there’s no
much difference on the performance of hydraulic tur-
bines within certain time range; analysis is done on data
in a period of the latest two months and the result are
shown in below Tables 1 and 2.
As the load increases, the motor efficiency is improved;
the motor efficiency could be adjusted on low loads; if
motor efficiency is 97.5%, the turbine efficiencies after
adjustment are: 96.04%, 95.76%, 93.47%, 95.88% re-
Referring to the performance curve of turbines in hy-
dropower station (Figure 5), it’s clear that the online
calculations of hydraulic turbine efficiency is in accor-
dance with the basic trend of the design curve, with the
best efficiency when turbines working at 27~29 MW.
Table 1. 30 MW performance comparison.
Item Unit 1 2 3 4
Power generation MW 30.70 30.71 30.7730.60
The water level m 1818.2 1818.0 1818.21818.4
Over the water flow m3/s 33.81 33.70 33.5734.03
Working water
pressure m 100.15 100.15 100.15100.15
Water consumption for
power generation m3/kwh 3.96 3.94 3.933.98
hydraulic turbine
efficiency % 95.45 95.84 96.3793.34
displacement mm 82.67 80.25 79.6384.92
Table 2. 27 MW performance comparison.
Item Unit 1 2 3 4
Power generation MW 26.94 27.35 27.76 27.25
The water level m 1818.2 1818.6 1817.21818.2
Over the water flow m3/s 29.03 29.56 29.6529.41
Working water
pressure m 101.5 101.5 101.5 101.5
Water consumption for
power generation m3/kwh 3.87 3.91 3.98 3.89
hydraulic turbine
efficiency % 97.52 97.23 94.91 97.35
displacement mm 71.78 70.88 71.70 73.56
Figure 5. Hydropower run-time performance of the screen.
Figure 6. Hydropower run-time performance of the screen.
The water density is considered as constant value tak-
ing into account that full workload time of the turbine
units are very close. The working water heads take the
same value as well, referring to Tables 1 and 2, the water
levels of the front pool remain around 1818 m with no
much difference, and all the turbine intake centre lines
are around 1708 m. By evaluating one month capacity
and water consumption figure of the power generation in
various workloads of the No.1 and No.3 units, taking
about 8000 sets of data each measuring point, compari-
son chart of the capacity and water consumption of the
power generation in various workloads of the No.1 and
No.3 units is produced in figure 6.
Figure 6 shows that No. 1 and No. 3 unit have similar
water consumption for power generation under 20 MW
load; both water consumption increases round 27 MW
load, and Unit No. 1 has a minimum consumption around
25.08 MW load while Unit No.3 has minimum consump-
tion around 27.09 MW. Comprehensive analysis indi-
cates that Unit No.1 should be put into operation when
load is low, while for heavy loads; the turbine efficiency
of Unit No. 3 is 1% higher than that of Unit No.1 even
the water consumption of Unit No.3 is higher.
In same way of comparison and analysis, relevant
characteristics such as relations appearing in curves be-
tween the power of hydraulic turbine and opening degree
Copyright © 2013 SciRes. EPE
D. Q. FENG ET AL. 67
of the guide vane valve within a unit can be produced.
5. Conclusions
Remote data collection of hydropower stations achieves
instant data analysis and display; resolve the online effi-
ciency calculation of the power of the hydraulic turbine
Through long-term operation practice, coupled with
the correct and reasonable approaches on data analysis,
the performance changes of turbines can be analyzed; not
only it provide the basis for the operation and manage-
ment staff to understand the performance of turbines and
make decisions, also it has significant guidance to sched-
ule optimization for power stations.
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Copyright © 2013 SciRes. EPE