U.S. patent application number 09/770375 was filed with the patent office on 2002-03-14 for uninterruptible duplexed power supply system, and unit plug-in structure for uninterruptible duplexed power supply system.
This patent application is currently assigned to Nihon Protector Co., Ltd.. Invention is credited to Imanishi, Tsurayoshi, Sakai, Setsuo.
Application Number | 20020031000 09/770375 |
Document ID | / |
Family ID | 18758582 |
Filed Date | 2002-03-14 |
United States Patent
Application |
20020031000 |
Kind Code |
A1 |
Sakai, Setsuo ; et
al. |
March 14, 2002 |
UNINTERRUPTIBLE DUPLEXED POWER SUPPLY SYSTEM, AND UNIT PLUG-IN
STRUCTURE FOR UNINTERRUPTIBLE DUPLEXED POWER SUPPLY SYSTEM
Abstract
It is an object of the present invention to provide an
uninterruptible duplexed power supply system that is highly
reliable and has excellent durability, with which a more compact
size and higher efficiency are both achieved, and with which a
malfunction of the power supply circuit can be repaired in a live
state. The present invention is characterized in that there are
provided a first unit 4 and a second unit 6 having their own power
supplies 1, a main component 10 to which the outputs of the first
unit 4 and second unit 6 are inputted is equipped with a secondary
DC output circuit 8 and a battery-side converter circuit 13, the
first unit 4 and the second unit 6 can be attached to and detached
from the main component 10 in a live state.
Inventors: |
Sakai, Setsuo;
(Amagasaki-shi, JP) ; Imanishi, Tsurayoshi;
(Amagasaki-shi, JP) |
Correspondence
Address: |
ARMSTRONG,WESTERMAN & HATTORI, LLP
1725 K STREET, NW.
SUITE 1000
WASHINGTON
DC
20006
US
|
Assignee: |
Nihon Protector Co., Ltd.
Amagasaki-shi
JP
|
Family ID: |
18758582 |
Appl. No.: |
09/770375 |
Filed: |
January 29, 2001 |
Current U.S.
Class: |
363/65 |
Current CPC
Class: |
H02M 7/003 20130101;
H02J 9/062 20130101; H02J 9/067 20200101; H02J 1/001 20200101; H02J
1/10 20130101; Y02P 80/10 20151101 |
Class at
Publication: |
363/65 |
International
Class: |
H02M 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 8, 2000 |
JP |
H12 (2000)-272478 |
Claims
What is claimed is:
1. An uninterruptible duplexed power supply system, comprising: a
first unit that uses a first power supply as its input source and
that houses a first primary circuit equipped with a switching
element on the output side; and a second unit that uses the first
power supply or a second power supply that is different from the
first power supply and that houses a second primary circuit
equipped with a switching element on the output side; wherein a
main component to which the outputs of the first unit and second
unit are inputted comprises: a primary winding of a high-frequency
transformer to which the first unit and the second unit are
connected via a connection component; a secondary DC output circuit
that is connected to a secondary winding of the high-frequency
transformer and supplies electrical power to a load; a PWM control
circuit for keeping the output from this secondary DC output
circuit at a constant voltage; and a battery-side converter circuit
that is connected via a tertiary winding of the high-frequency
transformer, is equipped with a switching element on the output
side, and is used for charging a rechargeable battery for backup in
the event of a power outage; wherein the first unit and the second
unit are removably installed in a live state between a connected
state in which they are electrically connected to the two primary
windings of the high-frequency transformer and a disconnected state
in which this connected state has been released; and wherein the
output signals from the PWM control circuit are controlled and
inputted to the gate circuits of the various switching elements of
the first unit, second unit, and battery-side converter
circuit.
2. The uninterruptible duplexed power supply system according to
claim 1, wherein, when the input source of either the first unit or
the second unit is a DC power supply, the number of turns of the
primary winding for connecting said first unit or second unit to
the high-frequency transformer is changed to a number of turns
corresponding to the DC voltage applied by said DC power
supply.
3. The uninterruptible duplexed power supply system according to
claim 1 or 2, wherein the first unit and the second unit are each
equipped with a load balancing terminal or a current balancing
terminal, and the load balancing terminals or current balancing
terminals of these units are connected to each other, or a
switching element drive pulse switching control circuit is provided
for switching the drive pulses for driving the switching elements
of the first unit and second unit, and the drive of the two units
is controlled by this switching element drive pulse switching
control circuit, whereby the loads of the two units are balanced,
or the two units are driven at a preset balancing ratio, or the two
units are driven at a balancing ratio programmed into the computer
that serves as the load.
4. The uninterruptible duplexed power supply system according to
any of claims 1 to 3, comprising: a malfunction detection circuit
for detecting a malfunction of the first unit or second unit; a
power outage detection circuit; an internal temperature detection
circuit for detecting the internal temperatures of the two units; a
cooling fan abnormal shutdown detection circuit for detecting the
abnormal shutdown of a cooling fan; an input current detection
circuit and current balancing detection circuit for the two units;
and a charging control circuit for detecting the state of the
rechargeable battery, such as the charge or discharge state of the
rechargeable battery, the battery temperature, the remaining
capacitance, or the estimated service life; and wherein maintenance
is performed by transferring the detection signals from all of the
above circuits by serial transfer to the computer that serves as
the load.
5. A unit plug-in structure in an uninterruptible duplexed power
supply system, wherein at least one of the first unit and second
unit according to claim 1 is structured such that it can be plugged
into a casing through an opening formed in the front thereof, the
unit is provided with a connector capable of connecting to or
separating from a connector provided to the casing side in the
course of the plugging-in or unplugging of the unit, and a plug-in
operation member for pushing and moving the front of the unit when
this unit is plugged in and for pulling and moving the unit when
this unit is unplugged is attached to the casing so as to be
swingable substantially around the horizontal axis.
6. The unit plug-in structure in an uninterruptible duplexed power
supply system according to claim 5, wherein the plug-in operation
member is equipped with a latching component that latches with a
latched component provided to the front of the unit when the
plug-in operation member is swung in the plug-in direction of the
unit and that unlatches when the plug-in operation member is swung
in the unplugging direction of the unit, and there is provided
fixing means for fixing the plug-in operation member to the casing
in a state in which the unit has been completely plugged in.
7. The unit plug-in structure in an uninterruptible duplexed power
supply system according to claim 6, the fixing means comprising: a
latched component that is provided to the casing; a latching
component provided to the plug-in operation member so as to be able
to latch and unlatch the latched component; and a slot provided to
a rotary shaft of the plug-in operation member so that the plug-in
operation member will be able to move up and down when the unit has
been completely plugged in.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an uninterruptible duplexed
power supply system for driving a load by the rectified output from
a commercial alternating current power supply (AC), for instance,
during normal operation and for driving the load by the output from
a direct current power supply such as a rechargeable battery in the
event of an abnormality such as a power outage, and more
particularly relates to an uninterruptible duplexed power supply
system used for the operation of critical devices such as burglar
alarms, fire alarms, communications systems, information systems
(such as server computers and factory automation personal
computers), precision medical devices, and automated machinery, and
to a unit plug-in structure for an uninterruptible duplexed power
supply system. "Power outage" as used herein refers to the cutoff
of the supply of power (current), such as when the power supplied
from an electric company is cut off, or when the supplied power is
cut off because a breaker is tripped, a device is unplugged, a wire
is cut, or the like.
[0003] 2. Description of the Related Art
[0004] Continuous, uninterrupted operation 24 hours a day for five
years, for example, is required of server computers and the like in
particular, and the power supply system shown in FIG. 9, for
instance, is typical of the structure thereof. This system
comprises an uninterruptible power supply (UPS) 90 connected to a
commercial AC power supply, two switching power supplies 91 and 92
to which the switching power supply that serves as the server
computer power supply is connected in parallel for the sake of
safety (duplexing), and two sets of diodes 93 and 94 for preventing
the current outputted from either of these switching power supplies
91 and 92 from sneaking into the other switching power supply, and
is designed so that electrical power can be supplied at all times
to the load. Therefore, if the switching power supply 91 should
suffer a malfunction due to a lightning surge, any of various
impulse surges, or the like being introduced into the AC input
line, then the other switching power supply 92 will take over and
be able to supply power to the load.
[0005] With the above structure, because the switching power
supplies 91 and 92 are connected in series to the uninterruptible
power supply 90, the total efficiency, which is obtained by
multiplying the 75 to 80% efficiency of the switching power
supplies 91 and 92 by the 75 to 80% efficiency of the
uninterruptible power supply 90, is only about 55 to 64%, so there
is a problem with energy loss.
[0006] Another problem is that because the uninterruptible power
supply 90 and the two switching power supplies 91 and 92 are all
separate components, not only is a large amount of space required,
but the cost is also high.
[0007] Also, the two diodes 93 and 94 for preventing sneak current
are required for each of the two switching power supplies 91 and
92, so a total of four or more diodes are required, which makes the
system bulkier and leads to lower efficiency through diode forward
loss.
[0008] The inventors have previously proposed a solution to the
above problems. This is discussed in Japanese Patent No. 2,702,048,
in which a primary circuit, equipped with a rectification circuit
for rectifying the alternating current from a commercial AC power
supply and switching elements or the like provided on the output
side of this rectification circuit, is connected to the primary
winding of a high-frequency transformer, a secondary DC output
circuit that supplies power to the load is connected to the
secondary winding of this high-frequency transformer, and a
battery-side converter circuit equipped with switching elements or
the like for operating according to the operating state of the
primary circuit is connected to the tertiary winding of the
high-frequency transformer. The result is an uninterruptible
switching regulator (uninterruptible duplexed power supply system)
that integrates the primary circuit (AC power supply circuit), the
battery-side converter circuit, the switching circuit provided on
the output side of these, and the secondary DC output circuit that
supplies power to the load.
[0009] Nevertheless, although the load can be driven on an
emergency basis by the battery-side converter circuit if the
primary circuit should suffer a malfunction, the damaged parts in
the malfunctioned primary circuit have to be replaced. This
replacement requires that the computer be temporarily shut down by
a specific operation, and the power supply then turned off, and
this shutdown operation is not only troublesome, but the computer
cannot be operated during the replacement work, resulting in the
problem that the safety and reliability of the power supply cannot
be fully ensured.
[0010] It is also difficult in structural terms to perform the
above-mentioned replacement of damaged parts in the primary circuit
right in the middle of (for a short time) the drive of the load by
the battery-side converter circuit.
[0011] Accordingly, the method that had to be adopted up to now was
to connect the above-mentioned uninterruptible switching regulator
(uninterruptible duplexed power supply system) in parallel, just as
with the switching power supplies 91 and 92 in FIG. 9. Furthermore
because the connection is in parallel, the diodes 93 and 94 in FIG.
9 are needed to prevent sneak current, and the only effect is that
the uninterruptible power supply (UPS) 90 is unnecessary, so there
is still room for improvement in terms of reducing the size so as
to take up less space, and lowering cost.
SUMMARY OF THE INVENTION
[0012] In light of the above situation, it is an object of the
present invention to provide an uninterruptible duplexed power
supply system that is highly reliable and has excellent durability,
with which a more compact size and higher efficiency are both
achieved, and with which a malfunction of the power supply circuit
can be repaired in a live state.
[0013] In order to achieve the stated object, the present invention
is characterized in that there are provided a first unit that uses
a first power supply as its input source and that houses a first
primary circuit equipped with a switching element on the output
side, and a second unit that uses the first power supply or a
second power supply that is different from the first power supply
and that houses a second primary circuit equipped with a switching
element on the output side, a main component to which the outputs
of the first unit and second unit are inputted comprises a primary
winding of a high-frequency transformer to which the first unit and
the second unit are connected via a connection component, a
secondary DC output circuit that is connected to a secondary
winding of the high-frequency transformer and supplies electrical
power to a load, a PWM control circuit for keeping the output from
this secondary DC output circuit at a constant voltage, and a
battery-side converter circuit that is connected via a tertiary
winding of the high-frequency transformer, is equipped with a
switching element on the output side, and is used for charging a
rechargeable battery for backup in the event of a power outage, the
first unit and the second unit can be installed or removed in a
live state between a connected state in which they are electrically
connected to the two primary windings of the high-frequency
transformer and a disconnected state in which this connected state
has been released, and the output signals from the PWM control
circuit are inputted to the gate circuits of the various switching
elements of the first unit, second unit, and battery-side converter
circuit.
[0014] Therefore, if the supply of power to the load is cut off due
to a power outage in the input of the first unit and second unit,
power can be instantaneously supplied from a rechargeable battery
and the load can be driven on an emergency basis, without being
shut down, for a time corresponding to the capacitance of the
rechargeable battery. Also the durability of the power supply
system can be enhanced compared to when only one unit is provided.
Because two units are provided on the primary side so that two
units are alternately driven, or when just one is driven during
normal operation and the other is driven for emergency use, for
example, and furthermore, even if one of the units should
malfunction, the other unit can provide drive, allowing the load to
be continuously driven even while the malfunctioning unit is being
repaired. A commercial AC power supply may be used as the input for
one of the two units, and the same commercial AC power supply as
above, or a different power supply, such as a generator, a solar
battery, or a rechargeable battery, may be used as the input for
the other unit. If the voltage of the primary circuit drops below a
specific voltage or drops to zero, then the switching element for
the battery-side converter operating with the rechargeable battery
as its input will switch from an idle or off state to an operating
state and supply power from the rechargeable battery to the load as
discussed above. The above-mentioned idle state refers to a state
in which the switching element repeatedly turns on and off in
synchronization with the switching element of the power supply
circuit, but current does not flow.
[0015] After the unit containing the malfunctioned primary circuit
has been removed, a unit containing a new (working) primary circuit
is installed and the commercial AC power supply is once again
turned on in a state in which the unit has been electrically
connected to the primary winding of the high-frequency transformer.
As a result, the switching element will switch to an idle or off
state to halt the supply of power to the load by the battery-side
converter circuit, and at the same time, the switching element of
the connected unit automatically switches to an operating state,
and the supply of power to the load by the battery-side converter
circuit is switched to the supply of power by the unit, at which
point the switching of the power supply circuits is concluded.
[0016] When the input source of either the first unit or the second
unit is a DC power supply, then the number of turns of the primary
winding for connecting the first unit or second unit to the
high-frequency transformer is changed to a number of turns
corresponding to the DC voltage applied by the DC power supply.
[0017] Using a DC power supply for the input source as above allows
the load to be driven by the DC power supply even if the commercial
AC power supply should be cut off.
[0018] The first unit and the second unit can each be equipped with
a load balancing terminal or a current balancing terminal, and the
load balancing terminals or current balancing terminals of these
units connected to each other, or a switching element drive pulse
switching control circuit can be provided for switching the drive
pulses for driving the switching elements of the first unit and
second unit, and the drive of the two units controlled by this
switching element drive pulse switching control circuit, thereby
balancing the loads of the two units, or driving the two units at a
preset balancing ratio, or driving the two units at a balancing
ratio programmed into the computer that serves as the load.
[0019] If there are provided a malfunction detection circuit for
detecting a malfunction of the first unit or second unit, a power
outage detection circuit, an internal temperature detection circuit
for detecting the internal temperatures of the two units, a cooling
fan abnormal shutdown detection circuit for detecting the abnormal
shutdown of a cooling fan, an input current detection circuit and
current balancing detection circuit for the two units, and a
charging control circuit for detecting the state of the
rechargeable battery, such as the charge or discharge state of the
rechargeable battery, the battery temperature, the remaining
capacitance, or the estimated service life, and if maintenance is
performed by transferring the detection signals from all of the
above circuits by serial transfer to the computer that serves as
the load, then the status of the uninterruptible duplexed power
supply system can be ascertained and appropriate steps taken.
[0020] The present invention also provides a unit plug-in structure
in an uninterruptible duplexed power supply system, wherein at
least one of the first unit and second unit according to claim 1 is
structured such that it can be plugged into a casing through an
opening formed in the front thereof, the unit is provided with a
connector capable of connecting to or separating from a connector
provided to the casing side in the course of the plugging-in of the
unit, and a plug-in operation member for pushing and moving the
front of the unit when this unit is plugged in and for pulling and
moving the unit when this unit is unplugged is attached to the
casing so as to be swingable substantially around the horizontal
axis.
[0021] Plugging the unit into the casing as above affords easy
replacement and maintenance of the unit. Also, the swing force of
the plug-in operation member is utilized as above so that the
connectors whose numerous contacts have been fitted together when
the unit was plugged in can be easily separated or connected. More
specifically, when the unit is plugged in, the front of the unit is
pushed and moved by the plug-in operation member, whereas when the
unit is unplugged, the unit is pulled and moved by the plug-in
operation member, which either connects or separates the
connectors.
[0022] The plug-in operation member may be equipped with a latching
component that latches with a latched component provided to the
front of the unit when the plug-in operation member is swung in the
plug-in direction of the unit and that unlatches when the plug-in
operation member is swung in the unplugging direction of the unit,
and fixing means may be provided for fixing the plug-in operation
member to the casing in a state in which the unit has been
completely plugged in.
[0023] This allows the plug-in operation member to be engaged with
and disengaged from the unit merely by swinging the plug-in
operation member as above. Also, fixing the plug-in operation
member to the casing by the fixing means in a state in which the
unit has been completely plugged in effectively avoids the problem
of the unit unintentionally coming unplugged.
[0024] The fixing means may comprise a latched component that is
provided to the casing, a latching component provided to the
plug-in operation member so as to be able to latch and unlatch the
latched component, and a slot provided to a rotary shaft of the
plug-in operation member so that the plug-in operation member will
be able to move up and down when the unit has been completely
plugged in.
[0025] With the above structure, the latching component of the
plug-in operation member can be latched to or unlatched from the
latched component on the casing side, and the unit fixed to or
unfixed from the casing, merely by moving the plug-in operation
member up or down in a state in which the unit has been completely
plugged in.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is an electrical circuit diagram of an
uninterruptible duplexed power supply system;
[0027] FIG. 2 is an electrical circuit diagram illustrating the
specific structure of the first unit (second unit) in the
uninterruptible duplexed power supply system;
[0028] FIG. 3 is an electrical circuit diagram illustrating the
specific structure of the battery-side converter circuit in the
uninterruptible duplexed power supply system;
[0029] FIG. 4 is an electrical circuit diagram illustrating another
structure of the first unit (second unit);
[0030] FIG. 5 is an electrical circuit diagram illustrating another
structure of an uninterruptible duplexed power supply system;
[0031] FIG. 6 illustrates an uninterruptible duplexed power supply
system, with (a) being a front view thereof and (b) a side
view;
[0032] FIG. 7 illustrates the first unit connection and
disconnection structure of the uninterruptible duplexed power
supply system, with (a) showing the state when the first unit has
been installed in the casing, (b) showing the state when the first
unit has been pulled forward, and (c) showing the state when the
first unit has been removed;
[0033] FIG. 8 is an oblique view showing the state just prior to
the installation of the removed first unit in the casing; and
[0034] FIG. 9 is a block diagram of the specific structure of a
conventional uninterruptible duplexed power supply system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] FIGS. 1 and 2 show a forward-type uninterruptible duplexed
power supply system. This uninterruptible duplexed power supply
system comprises a first unit 4 for rectifying the alternating
current from a commercial AC power supply 1 and outputting it to a
first primary winding N1a of a high-frequency transformer 3 via a
switching element 2 provided on the output side, a second unit 6
for similarly rectifying the alternating current from the
commercial AC power supply 1 and outputting it to a second primary
winding N1b of the high-frequency transformer 3 via a switching
element 5 provided on the output side, and two secondary DC output
circuits 8 and 9 that are connected in an electrically insulated
state to secondary windings N2a and N2b of the high-frequency
transformer 3 and that supply DC power to a load 7. A main
component 10 to which the outputs from the two units 4 and 6 are
inputted consists of the two primary windings N1a and N1b, the
high-frequency transformer 3, the secondary windings N2a and N2b,
the two secondary DC output circuits 8 and 9, and a battery-side
converter circuit 13. A forward type is shown here as the power
supply system, but a feedback type, full bridge type, half bridge
type, or the like may be used instead, and any type of power supply
system may be used.
[0036] There are provided a charging control circuit 14 and a
charging-use constant voltage circuit 15 connected via a tertiary
winding N3 of the high-frequency transformer 3, equipped with a
switching element 11 on the output side, and used for charging a
rechargeable battery 12 for backup in the event of a power
outage.
[0037] As shown in FIGS. 1 and 3, the battery-side converter
circuit 13 comprises the charging control circuit 14 for charging
the rechargeable battery 12, the charging-use constant voltage
circuit 15 for applying a constant voltage to this charging control
circuit 14, an anti-backflow diode 16 provided between this
charging-use constant voltage circuit 15 and the tertiary winding
N3, an FET 11 (switching element) that is operated by gate signals
from a gate circuit 17 and is connected to the tertiary winding N3
of the high-frequency transformer 3, a snubber circuit 18 provided
in order to absorb linking voltage or surge voltage affecting this
switching element 11, an anti-backflow diode 19 for preventing the
backflow of over current produced by induced voltage induced from
the units 4 and 6 to the battery-side converter circuit 13, and a
circuit cutoff fuse 20. 21 in the figure is a built-in diode of the
FET 11, and S is a temperature sensor for measuring the temperature
of the rechargeable battery 12.
[0038] The detected information from this temperature sensor S is
inputted to a microcomputer control circuit 62 (discussed below),
information such as the charge or discharge state of the
rechargeable battery 12, the remaining capacitance, and the
estimated service life is detected by the charging control circuit
14, and this various information is transferred to a CPU that makes
up part of the load 7 as serial signal output by a separately
provided microcomputer that makes up a charging control circuit
with the same structure as above. This transferred information may
be displayed on the display screen of the CPU.
[0039] Since the first unit 4 and the second unit 6 have identical
structures, only the first primary circuit A provided to the first
unit 4 (the second unit has a second primary circuit B) will be
described. As shown in FIG. 2, this circuit comprises a
rectification circuit 22 for rectifying the alternating current
from the commercial AC power supply 1, a surge current prevention
circuit 23, an active filter circuit 24 (may be omitted) that
serves to prevent higher-harmonic current, a smoothing capacitor 25
for storing the DC voltage from the active filter circuit 24, an
FET 2 (switching element) operated by gate signals from the gate
circuit 26 and connected to the primary winding N1a of the
high-frequency transformer 3, a snubber circuit 27 (may be omitted)
provided in order to absorb linking voltage or surge voltage
affecting this FET 2, an anti-backflow diode 28 for preventing the
backflow of over current produced by induced voltage from the
battery-side converter circuit 13 to the first primary circuit A of
the first unit 4, a limiting resistor 29 (may be omitted) for
limiting the over current, and a circuit cutoff fuse 30 (may be
omitted). 31 in the figure is a built-in diode of the FET 2, and NF
is a noise filter. The primary circuit A is provided with a power
outage detection circuit 32 for detecting a power outage from the
output of the rectification circuit 22, an internal temperature
detection circuit 33 for detecting the internal temperature from
information from a temperature sensor 33S that measures the
internal temperature, a current balancing circuit 36 for balancing
the input current value of the primary circuit B of the second unit
6 at a predetermined balancing ratio such that an input current
detection circuit 35 for detecting the input current detected by
the secondary winding of a current transformer 34, and the input
current thereof, are held at preset values, a malfunction detection
circuit 37 for detecting a malfunction of the FET from the output
of the FET 2 and the pulse signals of the gate circuit 26, and a
switching power supply circuit 39 for driving a cooling fan 38 or
ensuring a standby-use auxiliary power supply (+5 V). TH in the
figure is an output terminal for outputting the signals from the
internal temperature detection circuit 33, CP is an output terminal
for outputting the signals from the input current detection circuit
35, CBL is a current balancing terminal (may instead be a load
balancing terminal) for connecting the current balancing circuit 36
of the first unit 4 to the current balancing circuit 36 of the
second unit 6, UF is an output terminal for outputting the signals
from the malfunction detection circuit 37 in a state in which they
are electrically insulated by a phototransistor 40, PF is an output
terminal for outputting the signals from the power outage detection
circuit 32, F.ALM is an output terminal for outputting the signals
from the cooling fan 38, and P1 and P2 are output terminals of the
primary circuits A or B. Connecting the input/output terminal CBL
of the first unit 4 to the input/output terminal CBL of the second
unit 6 as above results in the load balancing of the first unit 4
and the second unit 6 by a predetermined balancing ratio, but the
two units 4 and 6 may be load-balanced by providing a switching
element drive pulse switching control circuit (not shown) for
switching the drive pulses for driving the switching elements of
the first unit 4 and the second unit 6, and controlling the drive
of the units 4 and 6 by this switching element drive pulse
switching control circuit, or the two units 4 and 6 may be driven
at a preset balancing ratio, or the two units 4 and 6 may be driven
at a balancing ratio programmed into the computer that serves as
the load 7. This balancing ratio may be set to any value.
[0040] The commercial AC power supply 1 was used for the inputs of
both the first unit 4 and the second unit 6, but a DC power supply
41 may instead be used as the input source for either the first
unit 4 or the second unit 6. In this case, the rectification
circuit 22, surge current prevention circuit 23, and active filter
circuit 24 of the primary circuit A or B are unnecessary. Also, the
number of turns of the primary winding N1a or N1b connected to the
high-frequency transformer 3 is changed to a number of turns
corresponding to the DC voltage applied by the DC power supply 41.
The output terminals in this case comprise P1 and P3. The rest of
the structure shown in FIG. 4 but not described is the same as that
in FIG. 2, with the same components labeled the same, and will not
be described again. The DC power supply 41 may be a generator, a
fuel cell, a solar cell, an atomic cell, or the like. The unit
whose input source is this DC power supply 41 may be used together
with the unit whose input source is the commercial AC power supply
1, or it may be used only when one of the units cannot be used due
to a power outage, damage, etc. Two units are provided in the
example given here, but three or more units may also be provided.
Increasing the number of units does make the system bulkier, but
benefits include greater output, reliability, and durability.
[0041] As shown in FIG. 1, the first unit 4 and the second unit 6
can be installed or removed between a connected state in which they
are electrically connected to the primary winding N1a or N1b of the
high-frequency transformer 3 and a disconnected state in which this
connected state has been released, which is accomplished by means
of a connector 42 (the connection component). Therefore, if the
first primary circuit A or the second primary circuit B should
malfunction due to a lightning surge, any of various impulse
surges, or the like, the primary circuit can be quickly and easily
replaced by removing the malfunctioning primary circuit A or B in
the above-mentioned disconnected state, and then attaching a new
primary circuit in a connected state by means of the connector 42.
When the new primary circuit is put in a connected state by the
connector 42, the backflow of over current caused by induced
voltage to the primary circuit A or B is prevented by the
anti-backflow diode 28, and current flowing to the smoothing
capacitor 25 can be controlled by the limiting resistor 29, so even
while the battery-side converter circuit 13 is operating, the first
unit 4 or the second unit 6 can be removed and installed in a live
state without any arcing of the connector 42 and fusion of the
contacts, or any damage to the electronic parts (elements, etc.)
that make up the primary circuit A or B. The above-mentioned
connector 42 consists of a male (or female) connector 42A provided
on the casing side (main component side), and a connector 42B
provided to the units 4 and 6 so as to allow connection to or
separation from this connector 42A.
[0042] The specific structure of a large-capacity uninterruptible
duplexed power supply system is shown in FIGS. 6(a) and (b). The
first unit 4, the second unit 6, and a battery unit 43 equipped
with the charging control circuit 14 and the rechargeable battery
12 are disposed in the upper, middle, and lower parts,
respectively, of a casing K with a vertical (up and down) dimension
T is 6U size (approximately 261 mm) and a horizontal (width)
dimension H of 4 slots (approximately 80 mm; available with up to
10 slots (approximately 200 mm)), but the dimensions of the units 4
and 6, the battery unit 43, and the casing K are not limited to
those given. With a small-capacity uninterruptible duplexed power
supply system, although not shown in the figure, the first unit 4
and the second unit 6 are next to each other in the horizontal
(width) direction of the casing K in which the vertical (up and
down) dimension is 3U size (approximately 130 mm) and a horizontal
(width) dimension of 4 slots (approximately 80 mm; available with
up to 10 slots (approximately 200 mm)), with the battery unit 43
disposed above or below the units 4 and 6, but the dimensions of
the casing K and the positions of the units are not limited to
those given here.
[0043] As shown in FIGS. 6(a) and (b), FIGS. 7(a), (b), and (c),
and FIG. 8, the first unit 4 and the second unit 6 (only the first
unit 4 is shown in the figures) are structured such that they can
be plugged into a casing through an opening formed in the front
thereof, the units 4 and 6 are provided with the connector 42B
capable of connecting to or separating from the male (or female)
connector 42A provided to the casing side (main component side) in
the course of the plugging-in of the units 4 and 6, and a plug-in
operation member 44, which is substantially U-shaped in front view,
for pushing and moving the fronts of the units 4 and 6 when the
units 4 and 6 are plugged in and for pulling and moving the units 4
and 6 when the units 4 and 6 are unplugged is attached to the
casing K so as to be swingable substantially around the horizontal
axis X of rotational shafts 45A of a pair of left and right
brackets 45 attached to the casing K.
[0044] A pair of left and right hook members 46 that are
substantially L-shaped in side view are attached as latched
components to the fronts of the units 4 and 6, there is provided a
pair of left and right pins 47 on inner surfaces of left and right
vertical plate portions of the plug-in operation member 44 as
latching components that latch these hook members 46 when the
plug-in operation member 44 is swung in the plug-in direction of
the units 4 and 6 and that unlatch when the plug-in operation
member 44 is swung in the unplugging direction of the units 4 and
6, and a fixing means is provided for fixing the plug-in operation
member 44 to the casing K in a state in which the units 4 and 6
have been completely plugged in.
[0045] The above-mentioned fixing means comprises a through hole 48
(the latched components) provided to the casing K, a latch 49
provided to the plug-in operation member 44 so as to be capable of
being plugged into and removed from this through hole 48, and slots
44A provided to the plug-in operation member 44 in order to allow
the plug-in operation member 44 to move up and down with respect to
the rotational shafts 45A in a state in which the units 4 and 6
have been completely plugged in.
[0046] Therefore, when the installed unit 4 or 6 is removed from
the casing K, first, the plug-in operation member 44 is left in its
current orientation (see FIG. 7(a)) and moved straight up by a
distance corresponding to the slots 44A, which removes the latch 49
from the through hole 48 (see FIG. 8) and releases the unit. When
the plug-in operation member 44 is swung upward in this state, as
shown in FIG. 7(b), the unit 4 or 6 is moved forward and, at the
same time, the connector 42B of the unit 4 to 6 is separated from
the connector 42A on the casing side. When the plug-in operation
member 44 is swung further upward, the pins 47 move upward from
grooves M of the hook members 46 and unlatch the unit, allowing the
unit 4 or 6 to be easily removed as shown in FIG. 7(c). When the
sequence is reversed and the unit 4 or 6 is plugged into the casing
K, first, the unit 4 or 6 is pushed into the casing K up to a
specific location. Then, the plug-in operation member 44 is swung
downward, causing the pins 47 to hit the tops of the hook members
46. When the plug-in operation member 44 is swung further from this
state, the pins 47 are engaged in the grooves M of the hook members
46 (see FIG. 7(b)) and, at the same time, both connectors 42A and
42B are connected to complete the plugging in of the unit 4 or 6,
and the plug-in operation member 44 is left in its current
orientation and moved downward, thereby fixing the unit 4 to 6 to
the casing K.
[0047] The above-mentioned limiting resistor 29 is provided in
order to output to the secondary DC output circuits 8 and 9 the
energy stored during the backup operation of the battery-side
converter circuit 13 by the smoothing capacitor 25 in order to save
the CPU processing contents in an internal backup memory in the
event that output cannot be supplied to the secondary DC output
circuits 8 and 9 for some reason during, such as a battery power
outage or a malfunction of the rechargeable battery 12, during the
backup operation of the battery-side converter circuit 13 that is
started as a result of interruption of AC output from the
commercial AC power supply 1 due to power outage and the like. The
smoothing capacitor 25 has an output time of about a few dozen
milliseconds. An advantage of providing the limiting resistor 29 is
that the above trouble can be eliminated, but this is not
absolutely necessary. Also, when the limiting resistor 29 is
provided, current will flow as charging current to the smoothing
capacitor 25 of the new unit when that unit is put in a connected
state by the connector 42, but because the current value is limited
by the limiting resistor 29, there will be no arcing, so this
current poses no problem.
[0048] As shown in FIG. 5, if the battery unit 43 is structured
such that it can be attached to and removed from the main component
10 via the connector 42, then the battery can be quickly replaced
merely by taking out the dead rechargeable battery 12 and plugging
in a new rechargeable battery 12. The rest of the structure shown
in the figure but not described is the same as that in FIG. 2, with
the same components labeled the same, and will not be described
again.
[0049] One (circuit 8 ) of the secondary DC output circuits 8 and 9
constitutes a first DC output circuit to which is connected a PWM
switching control circuit 50 for maintaining a constant voltage for
the load 7 equipped with a computer or the like equipped with a
CPU, a hard disk, other electronic circuits, etc., in which a
rectifying diode 51, a commutation diode 52, a smoothing coil 53,
and a smoothing capacitor 54 are connected to the secondary winding
N2a of the high-frequency transformer 3, and which supplies a
specific DC output current to the load 7. A DC/DC converter 55
allows the output from the circuit 8 to be taken off at a different
current value from the above-mentioned output. The other circuit 9,
although not necessary, constitutes a second DC output circuit in
which a magnetic amplifier 56, a rectifying diode 57, a commutation
diode 58, a smoothing coil 59, a smoothing capacitor 60, and a
control circuit 61 are connected to the secondary winding N2b of
the high-frequency transformer 3, allowing for the supply of power
at a constant voltage DC current different from that of the DC
output power from the circuit 8. Third and fourth DC output
circuits may also be provided as needed. Increasing the output in
this manner allows the DC output power to be varied as desired
according to the capacitance of the load 7 and other factors. Also,
using the PWM switching control circuit 50 to control the pulse
width of the gate signals outputted from the gate circuits 26 of
the units 4 and 6 allows a constant voltage to be maintained for
the load 7 via the first DC output circuit 8.
[0050] The three switching elements 2, 5, and 11 may be
synchronized so that control signals are always outputted from the
PWM switching control circuit 50 to the three gate circuits 26, 26,
and 17. Also, when the commercial AC power supply 1 is operating
normally, the switching elements 2 and 5 of the primary circuits A
and B may be put in an operating state and the switching element 11
of the battery-side converter circuit 13 put in an idle or off
state in synchronization with the switching elements 2 and 5, but
when the voltage from the commercial AC power supply 1 drops below
the specified level, the procedure is the reverse of the above,
with the switching elements 2 and 5 of the primary circuits A and B
being put in an idle or off state in synchronization with the
switching element 11, and the switching element 11 of the
battery-side converter circuit 13 put in an operating state.
[0051] A microcomputer control circuit 62, to which is inputted the
information from the five terminals (TH, CP, UF, PF, and F.ALM)
provided to each of the primary circuits A and B (for a total of 10
terminals), is connected to the load 7 by a bus 63 equipped with
serial transfer means (this bus is bi-directional in the figure,
but the transfer may be in just one direction, from the
microcomputer control circuit 62 to the load 7), and the charge and
discharge information from the charging control circuit 14 is
connected by a bus 63 and a bus 64 equipped with serial transfer
means. Therefore, the user can take the appropriate action if,
based on ten information from A to J and the charge and discharge
information from the charging control circuit 14, the various
displays are performed, such as a power outage display, a unit
malfunction display, a cooling fan malfunction display, a unit
internal temperature display, a display of the input current values
and balancing ratio of the units, or a display of the status of the
rechargeable battery 12, such as the state of charge of the
rechargeable battery 12, the battery temperature, the remaining
capacity, and the estimated service life. Also, drive pulse control
can be performed by a computer provided to the load 7 so that the
detected balancing ratio will be the predetermined balancing
ratio.
[0052] With a phase 1 of the present invention, the primary circuit
and the battery-side converter circuit are connected in parallel to
the load via a high-frequency transformer. As a result, the system
is more compact (takes up less space) and is more efficient, and
even if the primary circuit should malfunction due to lightning
surge, any of various impulse surges, or the like, power will be
supplied instantaneously from the rechargeable battery, so the load
can be driven continuously, without interruption, and reliability
is higher. Moreover, the malfunction of the primary circuit can be
eliminated quickly and easily merely by replacing the
malfunctioning primary unit with a new primary unit while the load
is in a drive state, which affords an uninterruptible duplexed
power supply system that is even more reliable. Furthermore,
because the entire unit is replaced, even an unskilled worker with
little electrical knowledge can replace the primary unit as long as
there is a new one, allowing the malfunction to be dealt with more
speedily. Also, a malfunction of the power supply circuit can be
eliminated in a live state, so the replacement is even faster.
[0053] If two units are provided on the primary side, such as when
two units are driven alternately, or just one is driven and the
other is reserved for emergency drive, then the durability of the
units will be better than when only one unit is provided. Moreover,
even if one unit malfunctions, continuous drive is afforded by the
other unit. Another advantage is that drive can be continued up
until the malfunctioning unit is repaired.
[0054] With a phase 2 of the present invention, one of the input
sources of the two units on the primary side is a DC power supply,
so even if the commercial AC power supply should be cut off, the
load can still be continuously driven by the DC power supply,
affording an uninterruptible duplexed power supply system with high
reliability.
[0055] With a phase 3 of the present invention, load balancing
terminals or current balancing terminals are provided to the first
and second units, and the load balancing terminals or current
balancing terminals of these units are connected to each other, or
a switching element drive pulse switching control circuit is
provided for switching the drive pulses for driving the switching
elements of the first unit and second unit, and the drive of the
two units is controlled by this switching element drive pulse
switching control circuit, thereby balancing the loads of the two
units, or driving the two units at a preset balancing ratio, or
driving the two units at a balancing ratio programmed into the
computer that serves as the load, and thereby achieving higher
efficiency.
[0056] With a phase 4 of the present invention, there are provided
a malfunction detection circuit for detecting a malfunction of the
first unit or second unit, a power outage detection circuit, an
internal temperature detection circuit for detecting the internal
temperatures of the two units, a cooling fan abnormal shutdown
detection circuit for detecting the abnormal shutdown of a cooling
fan, an input current detection circuit and current balancing
detection circuit for the two units, and a charging control circuit
for detecting the state of the rechargeable battery, such as the
charge or discharge state of the rechargeable battery, the battery
temperature, the remaining capacitance, or the estimated service
life, and maintenance is performed by transferring the detection
signals from all of the above circuits by serial transfer to the
computer that serves as the load. As a result, the status of the
uninterruptible duplexed power supply system can be ascertained,
appropriate action taken, and serious damage or the like
prevented.
[0057] With a phase 5 of the present invention, unit replacement or
maintenance of the machine containing the unit can be carried out
easily by plugging and unplugging the unit into and from the
casing. The connection and separation of the connectors whose
numerous contacts are fitted together are facilitated by utilizing
the swing force of the plug-in operation member when the unit is
plugged in and unplugged.
[0058] With a phase 6 of the present invention, the plug-in
operation member can be engaged with and disengaged from the unit
merely by swinging this plug-in operation member, allowing the
plug-in to be carried out more quickly. Also, fixing the plug-in
operation member to the casing by the fixing means in a state in
which the unit has been completely plugged in effectively avoids
the unintentional movement and unplugging of the unit.
[0059] With a phase 7 of the present invention, the latching
component of the plug-in operation member can be latched to the
latched component on the casing side, and the unit fixed to the
casing merely by moving the plug-in operation member up or down
when the unit has been completely plugged in. therefore, fixing and
releasing can be carried out more easily and quickly than when
screws are used, for example.
* * * * *