Note: Descriptions are shown in the official language in which they were submitted.
2~2~77
POWER SUPPLY TRSTING SYSTEM FOR NON-UTILITY POWER ~N~RATORS
AND SO ON
BACKGROUND OF THE IN~NTIoN
Field of the Invention
The present invention relates to a power supply testing
syste~ for non-utility power generators, etc. This testing
system, for instance, is used to test the power output of an
non-utility power generator provided in a high-rise
building, etc. in order to cope with such an emer~ent
situation as power breakdown.
Prior Art
Referring to Figure 6, there is illustrated a typical
system heretofore available in the art, in which three tanks
10 to be powered are provided, because a non-utility power
g2nerator to be subjected to power supply testing is
generally o~ a three-phase AC type.
Within each or the tank 10 there i5 located a main
electrode 15,'thë lower portion of which is supported on the
bottom of the tank 10 through an insulator 100.
Around the main electrode 14 there is located a
cylindrical insulator 16 which is vertically displaceable,
2~12~77
and the tank 10 is filled with a resistive liquid 12. The
tank 10 and main electrode 14 are connected to a non-utility
powder generator, not shown, by way of an output cable 104.
Then, a current is supplied between the tank 10 and the
main electrode 14 for the required time to test the power
generator for its output characteristics.
Load is regulated by the ver-tical displacement of the
insulator 16, and the resistive liquid 12 heated during
testing is pumped out by a pump 40 and fed through drain
pipes 110 and 112 to a radiator 42 wherein it is cooled down
and whence it is then returned to the tank 10 through supply
pipes 106 and 108.
With the above-mentioned prior art testing system,
however, there is a variation of as large as 15 ~ in the
liquid temperature rise between the tanks 10 to be powered
during testing.
For that reason, the resistance (or current) values of
the tanks 10 are so varied that a serious difficulty is
encountered in keeping the load, an important fac-tor for
testing, well-balanced. This in turn makes it very difficult
to perform a powder supply testing accurately.
When a certain tank 10 or electrode 14 breaks down
during testing, the testing should immediately be stopped.
In other word~, even a brea~down of one tank renders the
tssting system unserviceable.
In view of the foregoing, it is therefore an object of
this inven-tion to provide a power supply testing system
; - 2 -
2~2~7~
which assures a simple but accurate power supply testing and
con-tinues to work even when a certain tank or electrode
breaks down during testing.
SUMMARY OF THE INVENTION
In order to achieve the above-mentioned object, the
testing system according to this invention is constructed as
~ollows.
Referring to Fig. 1, there is shown a general embodi~ent
of the testing syste~ according to this invention.
As iliustrated, located above a common unit 20 are a
plurality o~ tank units 18 to be powered, each including a
tank 10 to be powered, a main electrode 14 and a movable
insulator 16. How many the tank units 18 are located is
determined by the number of phases of a non-utili-ty power
generator. At least one additional tank unit 18 is provided
for spare purposes.
The tank 10 is filled with a resistive liquid, and
includes a depending main electrode 14 which is supported
above. This electrode 14 is powered by a non-utility power
generator, etc. to be tested.
Between the tank 10 and the main electrode 14 there is
interposed the movable insulator 16 for regulating the
amount of a current passed therebetween.
~ ach or the tank 10 receives an inlet pipe 24 for
feeding the resistive liquid 12 to it, which branches off
2~2~77
from a main supply pipe 22. As can also be understood from
Fig. 1, each or the inlet branch 24 is provided with a flow
rate regulator member 26 for regulating the flow rate of the
resistive liquid 12.
According to this invention, the resist.ive liquids 12
filled in the tanks 10 for regular service can be maintained
at a substantially constant temperature, since the resistive
liquid 12 filled in the tank unit 18 for spare purposes
(which undergoes no temperature rise even during testing) is
distributed to the resistive liquids 12 contained in the
tank units 18 for regular service, so that their temperature
increases can be leveled out.
Further, at least one tank unit 18 provided for spare
purposes assures that the testing syste~ can continue -to
work even when a certain tank 10 or electrode 14 breaks
down.
Still further, the regulator 26 for regulating the flow
rate of the resistive liquid 12 attached to each tank 10
makes it possible to provide a more accurately controlled
leveling-out of the liquid temperature ri~es in the tanks
10 .
BRI~F DESCRIPTION OF TH~ DRAWINGS
The present invention will now be explained specifically
but not exclusively with re~erence to the accompanying
drawings, in which: -
g
2~2~77
Figure 1 i5 a general front view of o~e pre~erredembodiment according to this in~e~tion,
Figure 2 is a side view of Fig. 1,
Figure 3 is a piping circuit view showing details of the
flow passages of a resistive liquid,
Figures 4 and 5 are piping circuit views providing an
illustration of how the resistive liquid flowing through the
passages works, and
Figure 6 i9 a schematic view of one conventional system.
D~TAILRD EXPLANATION OF THE PREF~RRED EBMODIM~NTS
Referring to Fig. 1 showing a general structure of the
testing system according to this invention, four tank units
18 to be powered are located above a common unit 20.
Of these tank units, one is a spare, because a generally
available power generator is of a three-phase AC type.
~ ach or the tank unit 18 includes a substantially
cylindrical tank 10 to be powdered, which is located above
the common unit 20, a depending main electrode 14 housed in
the tank 10, and a movable insulator 16 interposed between
the tank 10 and the main electrode 14. The tank 10 is filled
with a resi~tive liquid 12, for which water i~ usually
employed.
It is noted that the tank 10 is provided on its upper
end with an overflow receiver me~ber 11 to accommodate to
the expansion of ~the resistive liquid 12 heated at an
2~2~477
initial stage of testing, thereby ensuring that a water
leakage is prevented, contributing to greater safety.
The tank 10 and main electrode 14 are both in
cylindrical forms for permitting a current to be smoothly
supplied between them.
The common unit 20 serves to collect the resistive
liquids 12 located above it and feed them to a radiator 42
to be described later.
The common unit 20 also serves to receive an amount of
air produced in the tanks 10 in operation and carry it to
the spare tank 10 for venting. This is because when much air
ic entrained in the tank 10, an arc occurs during testing,
putting load in a state so ill-balanced that no accurate
testing is achievable.
It is understood that an inlet pipe 24 covered with an
insulating material such as Teflon extends from above into
the tank 10, supporting the main electrode 14.
As illustra-ted in Fig. 1, the inlet pipe 24 is provided
at its upper end with a connecting terminal bar 32 through
an insulator 30. The bar 32 is in turn connected with a
cable of the non-utility power generator to be tested to
supply a current between the main electrode 14 and the tank
10 .
As again shown in Fig. 2, t~e movable insulator 16
interposed between the tank 10 and the main electrode 14 is
supported by an elevator 34.
As the movable insulator 16 is vertically displaced by
-- 6 --
2 ~ 7 ~
the elevator 34, the areas of the electrode 14 and tank 10
capable of being powered are varied to regulate the amount
of the current supplied.
Above the tanks 10 there is located a co~mon expansion
tank 36, which is connected with a plurality of the inlet
pipes 24 by way of fle~sible hoses 38 resistant to voltage
and corrosion.
The expansion tank 36 is provided with a main supply
pipe 22 for supplying the resistive liquid 12, and between
the e~pansion tank 36 and each flexible hose 38 there is
mounted a regulator valve 26 for regulating the flow rate of
the resistive liquid 12 flowing toward the inlet branch 24.
The common unit 20 located below the tanks 10 is
provided with a drain pipe 28 for draining off the resistive
liquid 12, said drain pipe 28 being equipped with a pump 40.
The drain pipe 28 is connected to the radiator 42 having
its outlet side connected with the main supply pipe 22 (see
Fig~. 1 and 3).
The resistive liquids 12 heated in the tanks 10 are Eed
through the drain pipe 18 to the radiator 42 in which they
are combined together and heat-exchanged or cooled down.
A~terwards, the combined and cooled liquid is again
distributed to ~the tanks 10 through the associated flexible
hoses 38 and inlet branches 24.
In this case, the regulator valve 26 o~ the spare tank
unit 18 is so closed that the resistive liquids 12 can
circulate through the remaining tank units 18.
2~ 7~
Although the resistive liquid 12 does not circulate
through the spare tank 10 as mentioned above, it is
distributed from the spare tank 10 to the resistive liquids
12 contained in the other tanks 10, so that the temperatures
of the resistive liquids 12 in the three tanks 10 in
operation can be substantially leveled out in cooperation
with the flow rate regulation achieved by the aforesaid
regulator valves 26. Thus, the loads on the tanks remain so
well-balanced that an accurate testing can be performed.
In order to prevent the temperature of the resistive
liquid 12 from exceeding the predeter~ined value during
operation, the radiator 42 is cooled by a fan 44.
It is understood that the resistive liquid 12, i~
required, may be filtered through a filter 46 ~especially
when the testing system is used for a high-voltage testing).
Referring to Fig. 3 showing a detailed circuit through
which the resistive liquid 12 is to flow, the drain pipe 28
attached to the common unit 20 is connected at the other
side to the inlet side of the radiator 42 through the pump
~0 .
The radiator 42 i5 also connected on the outlet side
with the main supply pipe 2Z.
Each or the inlet pipe 24 branching of~ from the main
supply pipe 22 is provided with the flow rate regulator
valve 26.
A liquid reservoir 54 containing a large amount of the
re~istive liquid 12 includes downwardly extending intake
7 ~
pipes 56 and 58, the former of which is connected to the
main supply pipe 22 by way of a pump 60 as well as pipes 62,
64 and 66.
Through a changeover valve 61 and a pipe 65, the pump 60
is connected to the main supply pipe 22 through which the
resistive liquid 12 leaving the radiator 42 flows.
The pipes 64 and 76 are connected with changeover valves
~0 and ~8, respectively.
Connected between the changeover valve ~0 and the pipe
76 is a pipe 72 which is in turn connected with a radiator
~4 and the filter 46. The changeover valve 78 is connected
on the other side with a water purifier 82.
The intake pipe 58 is connected to a spray pipe 86
through a pump 84.
Reference will now be made to how the flowing circuit
works. As illustrated, the resistive liquid 12 (or tap
water~ is pumped out from within the reservoir 54 through
the i~take pipe 56 (or from a tap 88), and is then supplied
through the pipes 62 and 72, radiator ~4, filter 46 and pipe
66 (if r~quired, through the water purifier 82) to the main
supply pipe 22, whence it is filled into the tanks 10
through the associated inlet branches 24.
As the tanks 10 are filled with the resistive liquids
12, the power generator connected to the tank~ 10 and main
electrodes 14 by way of cables, not shown, is put in
opera-tion and tested for a given time.
By way of example, a power output testing may be carried
g
2~2~47P~
out for about 3 hours with a power generator having an
output of 1000 KVA, a power factor Qf 0.8, a voltage of 415
V and a current value of 642.6 A.
During the testing, the resistive liquids 12 are fed by
the circulating-pump 40 from within the tanks 10 to the
radiator 42 through the draîn pipe 28, in which they are
combined together and cooled down. Afterwards, the combined
and cooled liquid is again supplied to the tanks 10 through
the main supply pipe 22 and then the inlet branches 24.
In the meantime, the fan 44 is driven while the
resistive liquid 12 is pumped out of the reservoir 54 by a
pump 84 and blown onto the radiator 42 from an injecting
nozzle 90 through the intake pipe 58 and spray pipe 86.
Then, the temperature of the resistive liquid 12 in each
tank 10 is so sensed to control the rotation of the fan 44
that it is always kept constant.
In the present invention, it is to be noted that since
the resistive liquid 12 is circulated for reuse, it is
likely to be contaminated with impurities in each tank 10
during testing.
If the resistive liquid 12 decreases in purity by
contamination with impurities (esp. during a high-voltage
testing), then its conductivlty increases, causing trouble
to the power output testing.
Such contamination has a particularly serious influence
upon the high-voltage testing, since the resistive liquid 1
used there~or is pure water.
-- 10 --
2 ~ 7 7
In the illus-trated embodiment, therefore, the resistive
liquid 1~ may be flushed during the testing.
For flushing, the valves 61 and 67 are changed over, as
illustrated in Fig. 3, to supply the resistive liquid 1~
cooled down in the radiator 42 to the pipe 6~ thrc~gh the
pipe 65 by the pump 60, whence it is supplied through the
pipe 72 to the separate radiator ~4 for further cooling.
The resistive liquid 12 leaving the radiator 74 is
supplied through the pipe 72 to the filter 46 in which it is
filtered. If required, it is further supplied to the water
purifier 82 in which its purity is increased.
The resistive liquid 12 with an increased purity is
supplied thxough the pipe 66, main supply pipe 22 and inlet
branches 24 into the tanks 10.
According to the instant embodiment as detailed above,
there are provided four tank units 18 leading to the common
unit 20. Of these tank units, one is used for spare
purposes~ The resistive liquid contained in this spare unit
can be u~ed to substantially level out the temperatures of
the liquids contained in the remaining three tanks 10 in
operation.
Thus, the tanks' internal resistivities are kept so
constant that the loads thereon can be leveled out, making
it pos~ible to test a non-utility power generator
accurately.
The flow rate of the resistive liquid 12 ~upplied to
each tank 10 is so controlled by the associated flow rate
-- 11 --
2~2~77
regulator valve 26 that its temperature can be controlled
more accurately.
Including the spare tank unit 18, the instant testing
system can continue to work by changeover operation, even
when a certain tank 10 or electrode 14 breaks down during
testing.
Since the resistive liquid 12 is not circulated through
the spare tank 10, it i5 also possible to vent air from the
common tank 20 through the spare tank.
It is therefore unlikely that air may be entrained in
the tanks 10 in operation, contributing to greater safety
during testing.
Whether or not the resistive liquid 12 is contaminated
with impurities can easily be ascertained by seeing through
the spare tank 10.
Since the main electrode 14 is supported at its upper
portion by the inlet pipe 24 and disposed within the
associated tank 10 in a depending manner, it is so
unnecessary to form any hole through the bottom of the
common tank 20 that the liquid is most unlikely to leak from
the common unit 20.
It w.ill be understood that while the present invention
has been described specifically with reference to its
speci~ically preferred embodiment, many modifications or
changes may be pos~ible within the scope o~ the invention
de~ined by -the appended claims.
- 12 -
