1 introduction
The frequency conversion velometer took one kind
of highly effective energy conservation the electrical machinery
speeder, because of it higher performance price compared to, obtained
the more and more widespread application in the factory. The
maintenance, the service, the test frequency conversion velometer work
changes day by day importantly, thus causes the frequency conversion
velometer service to test the platform to become the application
domain essential equipment. The Lai steel automation department
designed in 2002, sets up the frequency conversion velometer service
to test the platform. The frequency conversion velometer service
tests the platform mainly to be composed by two parts, service part
and measurement component.
2 frequency conversion velometers service
partial compositions
Formerly several time serviced the frequency
changer the experience to look that, with the strong electricity
correlation component, the high efficiency component, the power unit
as well as the corresponding actuation partial electric circuits
damage frequency was higher, certainly will be able to appear various
breakdown phenomenon in the later service process, the performance if
the corresponding electronic circuit concerns. The electronic
installation service process seeks a corresponding breakdown process.
In the service process, we or should persist take the person
primarily, the equipment as the auxiliary principle, fully displays
person's subjective initiative, reduces the service cost, obtains from
the breakdown phenomenon, analyzes the circuitry, the succession
relations, the work process, discovers each kind of possibility
existence the breakdown spot, then with the aid of some service
check-out facilities, the definite breakdown spot, the definite
breakdown primary device, (including determines the nature of with
quota target), then seeks the corresponding component to carry on the
replace, makes the equipment to restore its inherent performance
index.
Service process including following several aspects:
The first step, around inquired the user frequency changer the
breakdown phenomenon, has the external environment change including
the breakdown. For example, power source exceptionally
undulation, load change.
The second step, according to user's breakdown description, the
analysis possibly creates this kind of breakdown the reason.
The third step, opens the equipment which services, confirmed
the procedure which damages, the feasibility which the analysis
service restores.
The fourth step, according to is damaged the component the
working position, through reads the electric circuit, analyzes the
electric circuit principle of work, discovers damages the component
the reason, as well as some related electronic circuits.
The fifth step, seeks the correlation the component to carry on
the replace.
The sixth step, all possibly creates the breakdown in the
determination, all reasons all remove in the situation, the circular
telegram carries on the experiment, is making this step of time,
general request all external conditions all have, and cannot cause the
breakdown further to magnify.
The seventh step, in the equipment work normal situation, may
enter the next procedure, the system test.
2.1 services the platform
(1) logical analyzer: The logical analyzer has
many inputs channel, reflected was measured the signal level the
logical condition and the corresponding time, namely by the measuring
point binary code, the logical analyzer may simultaneously to the
logical level signal, the data bus signal, the address bus signal, the
chip input output and so on the multichannel digital signal logical
relations carry on the test and the comparison, fixed time tests the
function using the measuring instrument itself transient state,
catches the narrow pulse around the disturbance and the test point
profile, the logical analyzer specially suits to the numeral logic
circuit carries on the test and the analysis.
(2) simulates the oscilloscope: The oscilloscope is uses
for "the freeze" a simulated signal or changes the signal as necessary
the effective tool, may act according to on the display monitor the
static profile to analyze its characteristic, and selects the scale
according to the fluorescent screen on check to survey its parameter
value, through uses the oscilloscope, may measure signal extremely
real, direct-viewing reflection on screen, is advantageous for the
serviceman to measure the signal carries on the quota and the
qualitative analysis.
(3) transistor graphical representation meter:
Use: The test selects and matches the high efficiency
tube, the service high efficiency power source, UPS and so on.
Appendix 1: Integrated circuit voltage transmission
characteristic test panel use: The test selects and matches the
digital circuit, services each kind of digital intelligence measuring
appliance; Appendix 2: The field effect tube pairs the
test panel, the use: Selects and matches the field effect tube;
Appendix 3:0-3KV high pressure test panel.
(4) graphical representation meter: Tests the
GTR module and so on
(5) linear integrated circuit intelligence
parameter analyzer: Selects and matches the test to transport
puts and so on the linear circuit, the service calls the heavy
measuring appliance, the signal processing board.
(6) table model digital electric bridge:
Tests precise R, C, L, the service precision instrument, the
communication installment and so on
(7) general programming: The revision
copy each kind of program memory, services the computer, the
intelligent instrument measuring appliance as well as the intelligent
instrument instrumented data backup.
(8) integrated circuit reflectoscope reflector:
Tests each kind of digital integrated circuit, main
parameter: Brings the RS232 connection and programming decipher
software
(9) intelligent verification signal
generating device: Verification measuring instrument and so on, Japanese white light.
3 frequency conversion velometers
measurement component composition
The measurement component function was to already
the frequency conversion velometer performance test which serviced
completes. Through the inspection and the exchange, tests the
frequency changer the best load or the alternating current machine.
The our company frequency changer power from big arrives
slightly, each kind of specification all exists after, completes in
the service, if uses the same level power the electrical machinery to
do the load experiment, this need provides each kind of model
electrical machinery this is not realistic, also is unscientific.
According to the frequency changer operating instructions,
generally request the frequency changer load not to be lower than the
rated power 10%, we may consider the electrical machinery realizes
below 15kw with 3kw about the rank frequency changer load.
Realizes below 150kw with the 15kw electrical machinery the rank
frequency changer load. In view of the frequency changer load
electrical machinery cannot the idling situation, be allowed to use a
magnetic powder brake to simulate the electrical machinery load, the
magnetic powder brake may change the magnetic powder through the
change input voltage the gap, thus achieves the change load the goal.
The realization simulation frequency changer uses the scene the
goal, certainly also needs to examine other some assistances
parameter, like input voltage, electric current, output voltage,
electric current, as well as three-phase balanced situation, output
wave shape harmonic component. Below tests the platform to need
the equipment measuring appliance:
(1) three phase ac electrical machinery: Main
parameter: 3kW, 15kW
(2) magnetic powder brake: Main
parameter: 350N.m
(3) electric current sensor: Main
parameter: In the survey scope 0-50A, outputs 0-50Ma, the Beijing branch sea
(4) voltage pick-up: Main parameter:
In the survey scope 0-1000V, outputs 0-100mA
(5) simulates the electric current
demonstration table head: Main parameter: 0-50A, inputs
0-50mA
(6) simulates the voltage demonstration
table: Main parameter 0-1000V, inputs 0-100mA
(7) i=3 reduction gear
(8) small water pump: Use:
Magnetic powder brake cooling.
(9) 16 16 channels A/D transformation card: Main parameter: Inputs 0-10V
(10) 16 D/A transformation card: Main
parameter: Outputs 0-10V
(11) signal partial: The input, the
output signal respectively are the 0-10v voltage signal, the 0-20mA
electric current signal, the switch quantity and the pulse signal
(12) computer 1
(13) multi-purpose printer 1
4 systems characteristics
(1) the system structure is
reasonable, easy to operate;
(2) suits to each kind of brand frequency changer
carries on the service and the test;
(3) inputs the output signal completely, the
system composition is nimble;
(4) uses composition closed-loop control system
and so on the frequency changer and intelligence signal generating
device unit, simulates the scene input-output device.
(5) carries on the service and the test to the
many kinds of instruments measuring appliance;
(6) may carry on the test and the service to the
general module;
(7) to services, the test data carries on
processing, the demonstration and the printing.
5 concluding remark
Since the frequency conversion velometer service
has tested the platform to set up, overhauls frequency changer many,
to safeguards the production smoothly to carry on has played the
comparatively major role, simultaneously saves massively for the Lai
steel egressed the maintenance cost.
Reference
Measuring instrument instruction for use
Author synopsis
Zhou Yaozhong (1948-) senior
engineer in 1982 graduated from the Lai steel TV
University electronic technology specialty, was engaged in the
measuring appliance and the industrial automation work for a long
time.
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