This
device automatically control load distribution (proportional distribution
method) of plural number of generators. In this auto load-sharing controller,
minimum operation control for receiving power and high output operation control
for generators can be selective. At parallel operation of power receiving and
plural number of generators, received power is controlled and distribution
control is done depending on load. In the case the load is increased and
reached almost maximum capacity of generator, insufficient amount of power is
automatically born by power receiving.
When parallel
operation of generators alone is done, frequency control as well as generator
number control and distribution control are done. When this device is used
together with synchronizing device, power factor regulator and reactive power
distribution device, synchronization of and parallel operation of generator can
be done.
Description
of operation:
1. Isolation transducer circuit.: To obtain the voltage
signal in the range of 0~2.5V, DC current that is proportional to AC power is
input, pulse width modulated, isolated by a photo coupler, and is passed
through smoothing circuit.
2. Input voltage and frequency: input voltage is isolated by PT and passed
through effective value circuit to convert it into DC voltage (AC 150V/DC1.5V).
As for frequency detection, ¼ dividing is done after wave forming to be used as
the interval of input frequency.
3. A/D converter circuit: A total of seven circuits of five power
circuits, one voltage circuit, and A/D reference input are analog/digital
converted in the prescribed order by 13-bit A/D converter.
4. Control Input circuit: control input such as key set, effluent
designation, start destination and the like are isolated by the photo coupler
and taken inside.
5. Power receiving constant control value-Analog output: analog output is
operational at WRT=100% /DC 1mA, after the power receiving constant power value
under present control is transmitted to analog by D/A transmitter through
insulated circuit.
6. Alarm and start command output: alarm is output in the
event of generator inverse power or governor system failure erroneous designation.
Alarm output for error command is provide with timer 10S.this timer is compose
of software manner.
Stat
command; when receiving power exceeds WHG for more than 1 minute, generator
start is output. This is of or output with next generator start output
(instantaneous action).a timer (10 minutes) used here is composed of hard-ware
manner.
7. Control output: control output signal such as overload separation
designation possible and separation command are output respectively after
various conditions including load power, control input born by the generator
and the like are judged CPU.
8. Governor control output: when each generator output has a difference
of more than neutral zone compared with respective control target, generator
output is controlled by 15R and 15L signal so that it is maintained within
neutral zone.
9. CPU circuit: burden of each generator, load power, and frequency
are calculated. Power receiving constant power control and generator target
control are executed by control signal such as governor control, overload command,
start command, start command, and separation command according to the control
signal input from outside.
Interpretation
of the control data input by function key, and pulse width control of 15R and
15L signal are done too.
3.29
Maintenance of ALS:
Daily
inspection is not required especially. Take case of the following items
periodically.
Remove
dust adhered to this device
Check
the device for presence of loosened wiring and mounting machine screws.
Check
relays if they are replaced with correct interval.
Replacement
and maintenance interval of relays
Manufacture
and model number of the relay used (MY2, DC 24V,OMRON) make plug socket
connection
Working
condition and service life
Load
MM4XP (DC 100/110V), service life: 2 million times, open/close frequency: One /
20sec., estimated service life: approximately 460 days.
Replacement
and maintenance interval: replacement and maintenance of relays should be done
every year.
Replacement
and maintenance interval of relays: with this device, relays are arranged on
the interval print plate. Open body inside to conduct replacement and
maintenance of relays .take due care are that time so that dust may not enter
into device inside.
Remove
set screws (at four locations) at the side of terminal board, withdraw print plate
from the motherboard fixed at lower portion in the box, and replace the relay.
Remove
relay fixture for each relay. After replacement, restore this relay fixture. At
this moment, check if fixtures hook is surely engaged with socket of the relay.
Upon
completion, mount print plate to the motherboard by machine screws.
large reduction of the operating energy. These
breakers are available for indoor or outdoor applications, the latter being in
the form of breaker poles housed in ceramic insulators mounted on a structure.
Current
interruption in a high-voltage circuit-breaker is obtained by separating two contacts
in a medium, such as SF6, having excellent dielectric and arc
quenching properties. After contact separation, current is carried through an
arc and is interrupted when this arc is cooled by a gas blast of sufficient
intensity.
Gas
blast applied on the arc must be able to cool it rapidly so that gas
temperature between the contacts is reduced from 20,000 K to less than 2000 K
in a few hundred microseconds, so that it is able to withstand the transient recovery voltage that is applied across
the contacts after current interruption. Sulphur hexafluoride is generally used
in present high-voltage circuit-breakers (of rated voltage higher than 52
kV).In the 1980s and 1990s, the pressure necessary to blast the arc was
generated mostly by gas heating using arc energy. It is now possible to use low
energy spring-loaded mechanisms to drive high-voltage circuit-breakers up to
800 kV. Bearing: Supports revolving parts for stable revolution
The
synchronous generator most commonly used, the revolving –armature type AC exciter
is installed on the shaft used for DC excitation of the field coil. The output
is converted to DC with the silicon rectifier for supply to the coil.
No. of
Revs. And Poles
The relation between revolution speed and frequency
in generators is represented by the following formula
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