2. At present …
Monitoring of high-voltage equipment produced in the following
modes:
- Mode "off-line” – when disconnected from the network.
- Mode "on-line" – in operation under operating voltage.
Disadvantages of the mode "off-line" :
• long periods between tests, during which failures occur;
• the need for repair;
• not according to the individual measured parameters to the actual
parameters under operating voltage;
• test maintained equipment, in accordance with the instructions.
Disadvantages of the mode of "on-line" :
- the lack of methods of control of some parameters ;
2
3. At present
After defining the defect to a dangerous level (when operating
under operating voltage, the "on-line") to find the place of
formation of the defect
and
resolve it
diagnose of high voltage equipment are also produced
in the mode:
«off-line»
3
4. system «SIGMA»
The fundamental properties of the system :
1. produces diagnosis in complex control equipment groups
according to their functional purpose;
2. controls any number of equipment of substations, switchgear and
represents a single complex.
3. produces simultaneous control of the technical condition and
analysis of a large group of diagnostic parameters, allowing to
increase the reliability of condition monitoring;
4. forms conclusions about the technical condition and degree of
danger of defects;
5. determines a residual operation time in the formation and
development of defects;
6. works in real time, in a cyclic mode in the rate of flow of the
process and provides information about the technical condition of
the equipment to the operational personnel.
7. integrates into other systems that gives the most complete picture
of the technical condition of objects;
4
5. system «SIGMA»
the system allows you to:
to obtain the values
of the diagnostic
parameters actually
describing the
technical condition
of the equipment
to optimize the
mode of operation
of the equipment in
accordance with its
technical condition
prevent
accidents
5
6. system «SIGMA»
System «SIGMA» is primarily intended for monitoring of the main
high-voltage equipment, the most susceptible to developing defects.
Such equipment at the substation or electrical distribution equipment
include:
• power (auto)transformers ,
• shunt reactors,
• cable lines,
• measuring transformers of current and voltage,
• the capacitors are connected,
• switches,
• the surge arresters,
• electric motors / generators.
6
7. system «SIGMA»
Technical condition of control objects is determined by a group of
diagnostic parameters.
Reliability assessment of technical condition depends on the number and
function of the diagnostic parameters, as well as from mathematical models of
the linkages of diagnostic parameters. The more parameters involved in the
analysis and definition of a technical condition of objects, the higher the
reliability indicators of a technical condition of objects, the more reliable are
the results.
The largest number of diagnostic parameters is monitored at the control
power (auto)transformers, reactors, generators, gas insulated switchgear.
A smaller number of diagnostic parameters is observed during monitoring of
surge arresters, power cables and measuring transformers of voltage and
current.
What makes this different from the others?
7
8. system «SIGMA»
A simplified block diagram of algorithm of the system functioning
Xi – measured parameter; Xs – standard parameter;
Xd – level of danger defect; ta – predicted time of failure. 8
9. system «SIGMA»
The operation of the system
As noted earlier (see frames 2,3) the system can work in
a mode "off-line" and "on-line". The appropriate mode is
selected by personnel operating the controlled equipment.
The system work automatically on the two cyclic levels of
diagnostics:
- The first level is implemented in cases when all measured
diagnostic parameters are normalized values, Xi<Xs. The time
intervals between the measurement cycles of diagnostic
parameters are set by the operator in selecting the mode of
diagnosis.
- The second level is implemented in cases where at least
one of the measured diagnostic parameters exceeds normalized
values, XI>Xs.
9
10. system «SIGMA»
Block diagram of the system used with the equipment grouplowerlevel
ofsystem
average level
of system
upper level
of system
Transformer power
gas-insulated
switch
transformer
measuring
clutch
cable
surge
protector
converter
commutatorserver of system
commutator
module I/o data
measuring PD
gasanalyzer
weatherstation
AMS
local area network
sensor PD
sensor
electric motors
temperature
sensor
inlet of gas
analyzer
sensor density,
temperature and
gas pressure 10
11. system «SIGMA»
Resistance to failure
The law of aging of the object
Rf(t) = R0 [1- (t/tres)α], where
Rf - resistance to failure;
R0 – resistance to failure at t = 0
t – the current time;
tres – time between failures;
α – rate of aging.
af t = 0 resistance to failure Rf = 1.
at t = tрес resistance to failure Rf = 0.
Xi - measured diagnostic parameter,
Xn - normalized diagnostic parameter,
m - an indicator of the degree of danger.
The dependence of the resistance to failure
of Rf from the life time t in the formation of
various defects.
Residual life time Dtres = tf1 - td1
𝜶 = 𝟐 + (
𝑿 𝒊
𝑿 𝒏
𝑵
𝒊=𝟏 ) 𝒎
11
12. system «SIGMA»
The software system allows you to:
• to carry out the processing and analysis of signals
from equipment of the middle and lower levels of
system;
• to transmit data to adjacent systems (process
control system, relay protection and automation)
and upper level according to standard protocols
IEC 60870-5 101/104 , IEC-61850;
• to provide secure access to data and
management.
• maintain records of system operation;
• keep a log of events;
• to determine the technical condition of the
monitored objects;
• to determine the severity of the defect;
• provide the results of the processing to AWS
engineer;
12
17. system «SIGMA»
Visualization of the results of the PD control of power transformer 110 kV
Visualization of the results of the H2 control of power transformer 110 kV
17
18. system «SIGMA»
Thank you !
Limited Liability Company
«Energy.Microelectronics.Automatics»
2, Fedoseeva, Novosibirsk. 630089, Russia
ema.ru vvp@ema.ru +7 913 911 51 47
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