Guide to specification of hydraulic turbine control systems

EN following parallel vote

Leitfaden zur Spezifikation der Regelungssysteme für hydraulische Turbinen

Guide pour la spécification des régulateurs des turbines hydrauliques

Vodilo za določanje krmilnih sistemov vodnih turbin (IEC 61362:1998)

General Information

Status
Withdrawn
Publication Date
31-Mar-1999
Withdrawal Date
19-Apr-2016
Current Stage
9900 - Withdrawal (Adopted Project)
Start Date
19-Apr-2016
Due Date
12-May-2016
Completion Date
20-Apr-2016

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SLOVENSKI STANDARD
SIST EN 61362:1999
01-april-1999
9RGLOR]DGRORþDQMHNUPLOQLKVLVWHPRYYRGQLKWXUELQ ,(&
Guide to specification of hydraulic turbine control systems
Leitfaden zur Spezifikation der Regelungssysteme für hydraulische Turbinen
Guide pour la spécification des régulateurs des turbines hydrauliques
Ta slovenski standard je istoveten z: EN 61362:1998
ICS:
27.140 Vodna energija Hydraulic energy engineering
SIST EN 61362:1999 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

CEI
NORME
IEC
INTERNATIONALE
61362
INTERNATIONAL
Première édition
STANDARD
First edition
1998-03
Guide pour la spécification des régulateurs
des turbines hydrauliques
Guide to specification of hydraulic turbine
control systems
 IEC 1998 Droits de reproduction réservés  Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun any form or by any means, electronic or mechanical,
procédé, électronique ou mécanique, y compris la photo- including photocopying and microfilm, without permission in
copie et les microfilms, sans l'accord écrit de l'éditeur. writing from the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http: //www.iec.ch
CODE PRIX
Commission Electrotechnique Internationale
PRICE CODE XA
International Electrotechnical Commission
Pour prix, voir catalogue en vigueur
For price, see current catalogue

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61362 © IEC:1998 – 3 –
CONTENTS
Page
FOREWORD . 5
INTRODUCTION . 7
Clause
1 General. 11
1.1 Scope and object . 11
1.2 Normative references. 11
2 Terms, definitions, symbols and units . 13
2.1 General definitions . 13
2.2 List of terms, definitions, symbols and units. 13
2.3 Terms relating to the plant and the machines . 15
2.4 Terms relating to the control system. 17
3 Control system structure. 29
3.1 Main control functions . 29
3.2 Configurations of combined control systems . 31
3.3 Configurations of servo-positioners . 37
3.4 Multiple control. 37
4 Performance and components of the control systems . 39
4.1 Modeling and digital simulation. 39
4.2 Characteristic parameters for PID-controllers . 45
4.3 Other parameters of the control systems . 47
4.4 Functional relationship between servo-positioners . 51
4.5 Actual signal measurement . 53
4.6 Manual control . 57
4.7 Linearization . 57
4.8 Follow-up controls. 57
4.9 Optimization control . 59
4.10 Monitoring parallel positioning of amplifiers . 59
4.11 Provision of actuating energy . 59
4.12 Power supply for electronic control systems. 69
4.13 Operational transitions . 69
4.14 Safety devices/circuits. 73
4.15 Supplementary equipment . 75
4.16 Environmental suitability of governor components. 79
4.17 Electromagnetic compatibility . 79
5 How to apply the recommendations . 81
Data sheets 6.1a to 6.6d . 83 to 103
Annex A – Definitions . 105

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61362 © IEC:1998 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_________
GUIDE TO SPECIFICATION OF HYDRAULIC TURBINE
CONTROL SYSTEMS
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International Organization
for Standardization (ISO) in accordance with conditions determined by agreement between the two
organizations.
2) The formal decisions or agreements of the IEC on technical matters, express as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61362 has been prepared by IEC technical committee 4: Hydraulic
turbines.
The text of this standard is based on the following documents:
FDIS Report on voting
4/119/FDIS 4/142/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
Annex A forms an integral part of this standard.
The contents of the corrigendum of March 2000 have been included in this copy.

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61362 © IEC:1998 – 7 –
INTRODUCTION
Recent developments have led to more stringent control system requirements with respect to
power frequency regulation and to isolated network operation. These requirements essentially
concern the primary control, which due to the use of modern, mostly electronic components,
can be tasked with some additional control functions. Also the primary control responds to a
superimposed large network control system (secondary control).
This guide mainly deals with primary control specifications; additional tasks are covered but the
guide does not elaborate on specific details.
Specifically the primary control can include some or all of the following functions:
– unit start-up and shut-down;
– idling before synchronizing and after separation from the network and synchronizing;
– isolated network operation;
– parallel operation on large networks in speed control and power output control mode;
– head water level and/or flow control;
– operating mode transitions;
– monitoring and safety functions.
The guide also deals with aspects of the actuating energy supply.
The controlled system in a hydroturbine control loop, i.e., the respective transfer function, is
characterized by:
– the unit(s), i.e. turbine(s) and generator(s);
– the water passage system;
– the network to which the unit(s) is (are) connected;
– the modes of operation as mentioned above.
The parameters of the primary control system (speed governor, power output governor, etc.)
are to be carefully matched to the prevailing system conditions in order to:
– achieve adequate stability;
– satisfy performance requirements with respect to damping, response and accuracy;
– provide safety with respect to limitations in hydraulic transients, etc.
To achieve the above, in many cases modeling and simulations are valuable. The guide refers
to some important aspects in this respect.
Since the governors have to be able to cope with a range of conditions, it is suitable practice to
specify that a certain range for the setting of parameters is available in the governors. The
guide follows this practice in the relevant part.

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61362 © IEC:1998 – 9 –
Specifically, in this guide, the performance-relevant definitions refer to the PID-controller,
which can be implemented by analog or digital means. With appropriate microcomputer
technology, higher control algorithms also can be implemented. Although it is deemed difficult
to set up specific rules at the time of the issue of this guide, the general criteria for the
adequate performance of a control system are essentially independent of the control strategy
used. This means that they remain applicable as described in this guide and that the PID-
controller can be regarded and used as a reference governor to gauge the control performance
of a system.
The guide makes reference to IEC 60308 on hydraulic turbine control systems. It relies on it for
the methods of system identification and verification of performance, etc. It is the intention of
this guide to supplement IEC 60308 by recommending performance criteria and ranges for the
setting of parameters.
To facilitate the setting up of specifications, this guide also includes data sheets, which are to
be filled out by the customer and the vendor in the various stages of the project and the
contract.

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61362 © IEC:1998 – 11 –
GUIDE TO SPECIFICATION OF HYDRAULIC TURBINE
CONTROL SYSTEMS
1 General
1.1 Scope and object
This guide includes relevant technical data necessary to describe hydraulic turbine control
systems and define their performance. It is aimed at unifying and thus facilitating the bidding
specifications and technical bids. It will also serve as a basis for setting up technical
guarantees.
In case of separate vendors for different segments of a system, the interface between them is
especially important.
The guide is not confined to the control loop functions proper but includes all important
functions of a control system, i.e., it also treats sequencing functions, etc. Hydraulic turbine
control is thus understood to include:
– speed, power, water level and discharge control for reaction and impulse-type turbines
including double regulated machines;
– means of providing actuating energy;
– safety devices for emergency shut-down, etc;
– environmental performance criteria.
The guide aids the selection of some important parameters to be specified and checked in
relation to the different types of installations.
Excluded topics are acceptance tests, specific test procedures and guarantees.
1.2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this International Standard. At the time of publication, the editions
indicated were valid. All normative documents are subject to revision, and parties to agreement
based on this International Standard are encouraged to investigate the possibility of applying
the most recent editions of the normative documents indicated below. Members of IEC and ISO
maintain registers of currently valid International Standards.
IEC 60068-2-6:1995, Environmental testing – Part 2: Tests – Test Fc: Vibration (sinusoidal)
IEC 60308:1970, International code for testing of speed governing systems for hydraulic
turbines
IEC 61000-3-2:1995, Electromagnetic compatibility (EMC) – Part 3: Limits – Section 2: Limits
for harmonic current emissions (equipment input current ≤16 A per phase)
IEC 61000-3-3:1994, Electromagnetic compatibility (EMC) – Part 3: Limits – Section 3:
Limitation of voltage fluctuations and flicker in low-voltage supply systems for equipment with
rated current ≤16 A

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61362 © IEC:1998 – 13 –
IEC 61000-4-1:1992, Electromagnetic compatibility (EMC) – Part 4: Testing and measurement
techniques – Section 1: Overview of immunity tests
CISPR 11:1990, Limits and methods of measurement of electromagnetic disturbance
characteristics of industrial, scientific and medical (ISM) radio-frequency equipment
ISO 3448:1992, Industrial liquid lubricants – ISO viscosity classification
2 Terms, definitions, symbols and units
2.1 General definitions
This guide uses as far as possible the terms and definitions of IEC 60308. For clarification, the
simplified differential equation of the idealized PID-governor as used in this guide in
comparison with that of an idealized PI-governor used in IEC 60308 is given in annex A.
For the purpose of this International Standard the following definitions, as well as the
definitions given in IEC 60308, apply.
2.1.1
differential equation
equation describing the dynamic system behavior in the time-domain, as shown in annex A.
2.1.2
transient response
system response (output) to a step change of the input.
2.1.3
frequency response
dynamic response of the linearized system to a sinusoidal change of the input signal derived
from the differential equation by applying the Fourier transformation.
2.1.4
transfer function
dynamic response of the linearized system to an arbitrary variation of the input signal derived
from the differential equation by applying the Laplace transformation.
2.2 List of terms, definitions, symbols and units
Sub- Term Definition Symbol Unit
clause
2.2.1 Rated Subscript indicating the rated operation point of the system. r –
2.2.2 Subscript indicating maximum or minimum values of any term. max. –
Maximum
Minimum min.
2.2.3 Deviation of any term from a steady-state value –
Deviation Δ
2.2.4 Guide vanes Subscript associating a quantity to wicket gate ga –
2.2.5 Subscript associating a quantity to runner ru –
Runner
2.2.6 Nozzle Subscript associating a quantity to nozzle nz –
2.2.7 Subscript associating a quantity to deflector de –
Deflector

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61362 © IEC:1998 – 15 –
2.3 Terms relating to the plant and the machines
Sub-
Term Definition Symbol Unit
clause
–1
2.3.1 Specific energy Specific energy of hydraulic water available between the high- J ⋅ kg
E
and low-pressure side sections of the machine
of machine
2.3.2 Turbine head H =E/g definition of E, see 2.3.1 m
H
g = acceleration due to gravity.
–2
  = 9,81 m⋅s (at sea level)
2.3.3 Discharge Volume of water per unit time flowing through any section in 3 –1
Q m ⋅ s
the system
2.3.4 Number of revolutions per unit time
Rotational –1
n t ⋅ min
speed
2.3.5 Cycles per second f Hz
Frequency
2.3.6 Generator Generator power measured at generator terminals P W
G
output
2.3.7 Moment of Moment of inertia for calculation of fly-wheel effect. 2
kg ⋅ m
I
2 2
I = M D /4 = MR
inertia of mass
(M = mass, D = diameter of gyration,
R = radius of gyration)

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61362 © IEC:1998 – 17 –
2.4 Terms relating to the control system
Sub-
Term Definition Symbol Unit
clause
2.4.1 Controlled Variable which has to be controlled as speed n, output P ,
G
water level h:
variable
– absolute, dimensional value X var.

– relative deviation from a steady-state x

value, x = ΔX/X
r
x –
Rotational speed
n
x –
Output
p
x –
Water level
h
2.4.2 A signal which can be set by an external adjustment:
Command
signal
– absolute, dimensional value C var.
c –
– relative deviation from a steady-state value, c = ΔC/C
r

Rotational speed c
n

Output c
p

Water level c
h
2.4.3 Stroke of the main servomotor which moves the gate/runner
Servomotor
stroke blades/nozzles/deflectors
– absolute value Y m
y –
– relative deviation from a steady-state value, y = ΔY/Y
max
2.4.4 Controlled Adjusting range for the setting of the controlled variable with
an average setting of the permanent droop:
variable range
– maximum value of the controlled variable for Y/Y = 0 X –
max max
– minimum value of the controlled variable for Y/Y = 1,0 X –
min min
(see figure 1)
X
X
X
max
X
max
Y
Y
0
Y
Y max
max
1,0
X
min
X
min
IEC  320/98
Fig. 1
Figure 1 – Controlled variable range

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61362 © IEC:1998 – 19 –
Sub-
Term Definition Symbol Unit
clause
2.4.5 Governor output Output signal at the governor = input signal of the following
servo-positioner
signal
Relative deviation from a steady-state value s –
2.4.6 Output signal of Output signal of a pilot servo-positioner = input signal of
the following main servo-positioner
a pilot servo-
positioner
Relative deviation from a steady-state value –
s
v
2.4.7 droop graph: A graph showing the relative controlled variable as a function of the
relative servomotor stroke/the relative output under steady-state conditions (see figure 2).
X
X
b
b s
b b
pp s
Y P
Y P
, ,
0
Y P
1,0 Ymax rP
max r
Fig. 2
IEC  321/98
Figure 2 – Permanent droop
Sub- Term Definition Symbol Unit
clause
2.4.8 Permanent Slope of the droop graph (see figure 2):
droop
– at a specific point of operation, %
b
p
– defined by the end values of the droop graph b %
s
2.4.9 Proportional Proportional amplification, defined by the step of the governor K –
p
1)
transient function with b = 0, p = 0, T = 0 and input signal x = 1
gain
p p v
(see figure 3)
1)
Reciprocal value of the temporary speed droop, b , as per 5.3.5 of IEC 60308.
t

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61362 © IEC:1998 – 21 –
Y
Y
K
Kp
p
t
t
0
T
Ti
d
IEC  322/98
Fig. 3
Figure 3 – Integral time constant
Sub-
Term Definition Symbol Unit
clause
2.4.10 Integral action Time constant of the integral action of the governor, defined by T s
i
1)
time the slope of the governor step response curve with b = 0,
p
T = 0 and input signal x = 1 (see figure 3)
D
2)
2.4.11 Derivative Time constant of the derivative action of an idealized PID- T s
d
governor according to annex A. T can be realized
action time
v
approximately only by a derivative term multiplied by a first-
3)
order delay according to the transfer function of the
derivative part
k T p
D ⋅ 1d
1 + T p
1d
For small values of T p, then
1v
T = K ⋅ T
d D 1d
The step response of an idealized PID-governor according to
annex A, the proportional and integral term being zero, is
shown in figure 4.
1)
Damping time as per 5.3.4 of IEC 60308, T = K /K , K integral gain. T ⋅ T (IEC 60050-351).
d p I I
d i
2)
Realization also by second-order delay.
3)
T = K /K (IEC 60050-351) in parallel structured governors with gain adjustment, K = differential gain.
d D P D
In IEC 60308, no derivative action time is defined.

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61362 © IEC:1998 – 23 –
Y
y
0,63 K
0,63 K pD K v
K
KD p K v
t
t
0
T
1d
T
1v
IEC  323/98
Fig. 4
Figure 4 – Derivative time constant
Sub-
Term Definition Symbol Unit
clause
2.4.12 Dead band The maximum band between two values inside of which the i –
x
variation of the controlled variable does not cause any
governing action (see figure 5).
X
X
i
x
i
x
Y
Y
0
YY
1,0 mamaxx
IEC  324/98
Fig. 5
Figure 5 – Dead band
Sub-
Term Definition Symbol Unit
clause
2.4.13 One-half of the dead band i /2 –
Insensitivity
x
2.4.14 Minimum servo- The opening/closing time for one full servo-motor stroke at T , T s
g f
maximum velocity cushioning times disregarded (see figure 6).
motor opening/
closing time

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61362 © IEC:1998 – 25 –
Y
Y
Y
max
Y
max
1,0
t
t
0
TT
ff
T
Tg
a
IEC  325/98
Fig. 6
NOTE – In case of stepped opening/closing velocities a diagram may be provided.
Figure 6 – Minimum servomotor opening/closing time
Sub-
Term Definition Symbol Unit
clause
2.4.15 The reciprocal value of the slope of the curve showing the T s
Time constant
y
of the servo- servomotor velocity dy/dt as a function of the relative deviation
1)
of the position of the control valve, s, s , from the zero
positioner
v
position related to s, s = 1 (s, s = 1 theoretical relative spool
v v
stroke in the absence of feedback) (see figure 7)
1)
Servomotor response time as per 5.3.1 of IEC 60308.
ddy
y
ddt
t
1
1
T
y2
T 2
y
11
11
T
T T
g 1
g Ty
y1
1,0 s,s
v
s,s
v
1
1
T
fT
f
Fig. 7
IEC  326/98
Figure 7 – Time constant of the servo-positioner

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61362 © IEC:1998 – 27 –
Sub-
Term Definition Symbol Unit
clause
2.4.16 Amplifier dead The maximum band between the main servo-positioner i –
a
defined positions which can occur for a constant input signal
band
(see figure 8)
Y
Y
Y
max
Y
max
1,0
ii
a
a
0
1,0 s,s
v
,
s s
v
Fig. 8 IEC  327/98
Figure 8 – Amplifier dead band
Sub-
Term Definition Symbol Unit
clause
2.4.17 Amplifier One-half of the dead band i /2 –
a
inaccuracy
2.4.18 Control system Time interval between a specified change in speed or T s
q
command signal and the first detectable movement of the
dead time
servomotor (see figure 9)
yy
10%
≥ 10 %
T
q
T
a
t
0 t
IEC  328/98
Fig. 9
Figure 9 – Control system dead time

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61362 © IEC:1998 – 29 –
Sub-
Term Definition Symbol Unit
clause
2.4.19 Actuating energy Required energy for one servomotor stroke under the E N · m
R
minimum required pressure p = E /V
R R S
3
2.4.20 Servomotor Oil volume of the servomotors V m
S
volume
3
2.4.21 Tripping oil Oil volume of the pressure tank at the tripping point V m
T
volume (between p and p , see figure 20)
T R
3
2.4.22 Usable oil volume Usable oil volume between p and p V m
O min R u
(figure 20)
3
2.4.23 Residual (not Oil volume of the pressure tank after a full-load shut-down V m
res
usable) oil volume from the tripping point
(figure 20)
1)
2.4.24 Design oil Design pressure of the oil pressure tank p Pa
D
pressure
1)
2.4.25 Operating oil Operating oil pressure under normal operating condition p Pa
O
pressure
1)
2.4.26 Tripping oil When the tripping pressure p is reached after a full-load p Pa
T T
pressure emergency shut-down, it implies p < p < p < p
R T O D
1)
2.4.27 Minimum required Minimum required pressure in the oil servo system p Pa
R
pressure
1)
The unit bar is also used.
3 Control system structure
In the hydraulic turbine control, various tasks can be specified with varying priority. Realization
leads to certain typical control system structures and in turn to some basic rules to be adhered
to.
Such typical arrangements are compiled for clarification.
3.1 Main control functions
In hydraulic turbine control, these major control functions can be distinguished:
– speed control;
– power output control;
– level control;
– opening and flow control.
In some systems combinations of these control functions also occur.

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61362 © IEC:1998 – 31 –
3.1.1 Speed control
The purpose of the speed control basically is to maintain constant frequency. In the various
modes of operation this means that:
– in the isolated network mode, the actual speed and therefore the frequency corresponds to
the command signal setting;
– in the operation on the grid, where the speed is determined by the network frequency, the
speed control contributes to the network frequency control through the permanent droop
and the dynamic characteristics of the controlled system;
– in the idling mode (before synchronization and after separation from the network), the
actual speed corresponds to the command signal or the existing network frequency with
some slip.
3.1.2 Power output control
The power output control with a separate power governor is applied with the unit connected to
the grid, its purpose is to control the power output of the unit according to a power command
signal irrespective of head variations. Any frequency variations influence the power level
additionally via the permanent droop.
It is noted that in the cases where head variations can be ignored, a closed loop power output
control, i.e., a power output governor, may not be necessary. In such a case, linearization
between command signal and power output may suffice (see 3.2.1). In this case also, any
frequency variations influence the power level additionally via the permanent speed droop.
3.1.3 Level/flow/opening control
The purpose of a level/flow/opening control is to keep the level, flow or opening constant or to
make it follow a command signal.
3.2 Configurations of combined control systems
In combined systems, each control function can be assigned to a separate controller. However,
the controllers all actuate the same main servo-positioner through the opening setpoint.
Thereby, a bump-free switch-over between modes requires attention. In case of separate
controllers, parameters shall be set according to the respective control loop. Level and power
output control, etc, are often incompatible with the maintenance of speed in an isolated
network. The speed governor always remains functional for safety reasons, e.g., to take over in
the case of a load rejection.
3.2.1 Parallel structure
Two governors are arranged in parallel and actuate one or several servo-positioners via a
selector or a summing point. If a selector is applied, it often includes a max./min. function for
the speed control loop to prevail in the case of a load rejection.

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61362 © IEC:1998 – 33 –
If a summing point is applied, the switching of signals is avoided, but the power output
governor then influences speed control additionally and shall be set to ensure stability.
x
n
Speed governor
c
n
Selector or
y
summing
Servo-positioner
x
p
point
Power output governor
c
p
IEC  329/98
Figure 10 – Control system with speed and power output governor in parallel
The configuration according to figure 10 is often used in peak-load power stations.
x
n
Speed governor
c
n
Selector or
Servo-positioner y
summing Linearization
point
c
p
IEC  330/98
Figure 11 – Control system with speed governor and
power command signal in parallel
Figure 11 shows an arrangement with speed governor and power command signal in parallel
according to 3.1.2.
x
n
Speed governor
c
n
Selector or
y
summing
Servo-positioner
x
h
point
Water level controller
IEC  331/98
c
h
Figure 12 – Control system with speed governor and level controller in parallel

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61362 © IEC:1998 – 35 –
3.2.2 Series structures
Power output governor or level controller precede the speed governor. They actuate the speed
signal setter of the speed governor (figure 13) or the opening limiter (figure 14).
c
n
c
p
Selector or
y
Power output governor
summing Speed governor Servo-positioner
x
p
point
x
n
IEC  332/98
Figure 13 – Governing system with power output and speed governor in series
The power output governor actuates the speed signal setter of the speed governor.
Opening limiter
x
h
Water level controller
c
h
x
n
Speed
y
Servo-positioner
governor
c
n
IEC  333/98
Figure 14 – Governing system with level controller and speed governor in series
The level controller actuates the opening limiter of the speed governor.
The configurations of figures 13 and 14 are typical examples. However, there are also
configurations with the power output controller acting on the opening limiter of the speed
governor or with the level controller acting on the speed signal setter. In the power output and
the level control mode, the spee
...

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