JPH0686567A - Power conversion apparatus - Google Patents

Abstract

PURPOSE:To enable operations of maintenance and inspection to be performed safely without stopping power supply to a load by constructing a power converting section and a detection and drive circuit by a plurality of units and providing, in a rear portion of each unit, a cooling fan and a circuit connecting portion that effects connection when the unit is inserted. CONSTITUTION:A converter 5, an inverter 7 and DC capacitor 6 are constituted of a plurality of (N) units 23A-23N having the same rating and a capacity that is 1/N of an installed capacity. These units 23A-23N are stacked in a box-shaped body in a freely drawable manner, and conductors connected to a bus bar provided in a rear portion of the box-shaped body are projected from rear portions of the respective units 23A-23N. In each of the units 23A-23N, a detection and drive circuit 10 and a cooling device 11 are incorporated and a multi-conductor connector for connecting the detection and drive unit 10 to an external control circuit 12 is provided. With this constitution, operations of maintenance and inspection can be performed safely without stopping power supply to a load 9 by sequentially drawing the units 23A-23N.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power conversion device,
In particular, the present invention relates to a power conversion device capable of inspecting and exchanging components and the like of a power conversion device and increasing / decreasing a rated capacity without stopping power supply to a load.

[0002]

2. Description of the Related Art As is well known, converters and inverters require a cooling device for cooling the heat generated from power semiconductor elements constituting these power conversion devices. In particular, this heat increases as the capacity of the power converter increases, so that the cooling device adopts the forced air cooling method or the forced water cooling method. FIG. 4 shows a conventional uninterruptible power supply device in which an inverter as a power conversion device is incorporated.

In FIG. 4, 1 is an AC input power source, 2 is a storage battery for backup in case of an abnormality such as a power failure or momentary voltage drop of the AC input power source 3, 3 is a main AC input circuit breaker, and 4 is a main DC input circuit breaker. 5 is a converter for converting the electric power supplied from the AC input power source 1 into DC power, and 6 is this converter 5
DC capacitor that smoothes the DC voltage converted by
Is an inverter for inversely converting the DC power converted by the converter 5 or the DC power from the storage battery 2 into AC power, 8 is a main AC output circuit breaker, and 8a is a parallel bus bar.

Further, 9 is a load such as an electronic computer, 10 is a detection / drive circuit for driving the converter 5 and the inverter 7 to detect the voltage / current of each part, and 11 is the converter 5
A cooling device that cools the heat generated from the elements of the inverter 7 and the inverter 7, and a control circuit unit 12 that controls the converter 5 and the inverter 7.

In the uninterruptible power supply configured as described above, when the AC input power supply 1 is normal, the AC power supplied from the AC input power supply 1 is input to the converter 5 via the circuit breaker 3. With this converter 5,
Converted to DC power. A part of this DC power charges the storage battery 2 via the main DC breaker 4, and most of the DC power is converted back to AC power by the inverter 7, and the load 9 via the AC output breaker 8 Is powered.

On the other hand, when an abnormality (for example, a power failure or an instantaneous voltage drop) occurs in the AC input power source 1, the converter 5 shifts the gate to block the gate, and the DC power from the storage battery 2 receives the DC input breaker. It is supplied to the inverter 7 via 4 and supplies AC power to the load 7. In this way, power is supplied to the load 7 without interruption. For the cooling device 11 used in this uninterruptible power supply, forced air cooling is generally adopted, and a cooling fan is used.

Next, FIG. 5 shows an AC output switch 14 and a thyristor switch instead of the AC output breaker 8 shown in FIG.
FIG. 3 is a diagram showing an example of an uninterruptible power supply device to which 15 is connected and a function of switching AC power supplied through a backup AC input circuit breaker 13 and AC power from the inverter 7 without interruption is added.

In FIG. 5, the inverter 7 is operated in synchronization with the AC input power source 1, and should the inverter 7 operate,
When a failure occurs, the AC output switch 14 is switched to switch the power supply from the AC input power supply 1 without interruption. Through this series of operations, power supply to the load 9 is performed without interruption. Therefore, since the thyristor switch 15 having a short-time rating is used, the amount of heat generated is small, but the converter 5 and the inverter 7 generate heat due to continuous energization, and are therefore always cooled by the cooling device 11.

By the way, since the cooling fan incorporated in the cooling device 11 uses a motor as a drive source and a bearing incorporated in the rotary shaft, it is inspected about once every two years. Parts must be replaced if necessary. Further, the DC capacitor 6 connected to the converter 5 and the inverter 7 is also required to be inspected once every 5 to 7 years and replaced if necessary in order to improve the reliability of the power supply of the UPS. Is.

[0010]

However, the power conversion device thus configured has the following problems associated with the inspection and replacement work.

(1) In the uninterruptible power supply device shown in FIG. 4, the operation of the device must be stopped, and in order to continue supplying power to the load 9, the increased capacity of the stopped device is used as the bus 8
a must share. Therefore, in the case of a parallel redundant operation system with two uninterruptible power supplies, redundancy is lost.

(2) In the uninterruptible power supply system shown in FIG. 5, power is continuously supplied from the AC input power supply 1 to the load 9 via the backup AC breaker 13 and the AC output switcher 14. However, if the AC input power source 1 is
When an abnormality such as a power failure or an instantaneous voltage drop occurs, the load 9 cannot be supplied with power. (3) Even if the device is stopped for inspection, the live line part connected to the AC input power source 1 and the bus bar 8a remains inside the device, making inspection and replacement work difficult.

Further, not only this inspection / replacement work problem, but also after the completion of the equipment, if the load capacity increases by 10 to 20%, one more device is added, or it is commensurate with it. Must be replaced with a larger capacity device.

Therefore, the object of the present invention was made in view of the drawbacks of such a conventional power converter, and the apparatus is stopped even when the cooling fan, the DC capacitor, etc. are inspected and replaced. It is an object of the present invention to provide a power conversion device that is safe and has no restrictions on work by a live line part and that can easily increase the capacity of equipment.

[0015]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a power supply which is provided with a conversion section composed of a converter and an inverter, and a detection / drive circuit for driving the conversion section and detecting a voltage / current. In the converter, the converter and detection
The drive circuit is composed of a plurality of units that are one-several of the installed capacity, and this unit is housed in a box so that it can be pulled out in multiple stages. It is characterized in that a connecting part and a cooling fan are provided.

[0016]

[Function] During maintenance / inspection, by pulling out a plurality of units in order, necessary work can be performed safely and easily without stopping power supply to the load.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a main circuit single wire connection diagram showing a power conversion device of the present invention, and is a diagram corresponding to FIG. 4 showing a conventional technique.
Therefore, the same elements as those in FIG.

In FIG. 1, on the load side of the main AC input circuit breaker 3, a plurality of (note; 6 in FIG. 1) AC input circuit breakers 20A, 20B ... 20N for inspection are respectively connected in parallel. Similarly, on the load side of the main DC input or the circuit breaker 6, six inspection DC input circuit breakers 21A, 21B ... 21N are also connected in parallel. On the other hand, the main AC output circuit breaker 8
Also on the power supply side of the, six AC output circuit breakers 22A, 22B for inspection
22 N are connected in parallel.

Of these, each of the AC input breakers for inspection 20A,
20B ... 20N has a current carrying capacity of about 6 of that of the main AC input circuit breaker 3.
It is one-third. Furthermore, DC input circuit breaker for each inspection
The current carrying capacity of 21 A is about one sixth of that of the main DC input circuit breaker 4, and the current carrying capacity of each inspection AC output circuit breaker 22A, 22B ... 22N is about one sixth of that of the main AC output circuit breaker 8. ing.

Among these circuit breakers, the load side of the AC input circuit breaker 20A for inspection and the DC input circuit breaker 21A for inspection and the power source side of the AC output circuit breaker 22A for inspection are connected to the converter 5A via a disconnecting section. Inverter 6A and DC capacitor 6A
The conversion unit consisting of is connected. This conversion unit
The drive circuit 10A and the cooling device 11A are incorporated into a unit 23A indicated by a dotted line. This unit 23A has
A multi-core connector for connecting the detection / driving unit 10A and the external control circuit 12 is provided as indicated by a disconnection symbol.

Similarly, on the load side of the AC input breaker 20B for inspection and the DC input breaker 21B for inspection and on the power supply side of the AC output breaker 22B for inspection, a converter, an inverter and a DC capacitor are connected via a disconnecting section. Is connected. This converter is incorporated in the unit 23B indicated by the dotted line together with the detection / drive circuit and the cooling device.

In this way, the next unit 23C is connected to the load side of the inspection AC input circuit breaker 20N and the inspection DC input circuit breaker 21N and the power source of the inspection AC output circuit breaker 22N connected at the final stage. The side is connected to a converter including a converter, an inverter, and a DC capacitor via a disconnector. This converter is incorporated in the unit 23N indicated by the dotted line together with the detection / drive circuit and the cooling device. Next, FIG. 2 is a perspective view showing a state where the power conversion device connected as shown in FIG. 1 is housed in the box 30.

In FIG. 2, at the front end on the left side of the box body 30,
A door 31 is provided, and a control circuit unit 31 composed of a printed wiring board is attached to the back surface of the door 31.
One side of the flat cable 35 is connected to the hinge side of 31.

The box body 30 is composed of three surfaces in the left-right direction. Of these, the right end box body 30c accommodates the main AC output circuit breaker 8 in the lower stage, the storage battery 2 in the middle stage, and the upper stage in the upper stage. Each main AC input circuit breaker 3 is housed.

An AC input breaker 20A for inspection is housed at the left end at the upper end of the middle box 30b, and a DC input breaker 21A for inspection and AC for breaker are provided on the right side of the AC input breaker for inspection 20A. The output breaker 22A is housed in order. On the further right side of the inspection AC output circuit breaker 22A, the inspection AC input circuit breaker 20B, the inspection DC input circuit breaker 21B and the inspection AC output circuit breaker 22B shown in FIG. 1 are housed in order. Further to this right is the unit to which these circuit breakers are connected.
An AC output breaker 22C for inspection connected to the unit 23C housed under 23B is housed in order.

Similarly, a check AC input circuit breaker 20D is accommodated from the left side at the upper end of the left box 30a, and a check DC input circuit breaker and a check are provided on the right side of the check AC input circuit breaker 20D. AC input circuit breakers for inspection are accommodated, and the AC input circuit breakers for inspection 20N shown in FIG.
DC input circuit breaker for inspection 21N and AC output circuit breaker for inspection 22
N are stored in order.

Among these circuit breakers, the unit 23 is arranged in order from the bottom in the lower part of the circuit breaker housed in the intermediate box body 30b.
The A, 23B and the unit 23C are housed in such a manner that they can be drawn out in order via the left and right rails 32A, and the box body 30a at the left end also houses the units 23D, 23E and the unit 23N which can be drawn in order from the top.

Each of these units 23A, 23B, 23C, 23
Handles 23a are attached to the left and right on the front surfaces of D, 23E, and 23N, and a connector 44 is attached to the lower middle portion.
The connector connected to the right end of the flat cable 35 is inserted into the connector 44. Box 30a and box 30
A rectangular exhaust port 33 is formed on each ceiling plate b. FIG. 3 is a view showing the units 23A ... 23N shown in FIG. 2, (a) is a plan view, (b) is a front view, (c) is a rear view, and (d) is a right side view.

In FIG. 3, at the rear end of the unit 23A (23N), at the left end in the plan view of FIG. 3 (a), the male side connected to the load side of the AC input circuit breaker 20A (20N) for inspection. The conductor 40 is projected. On the right side of the conductor 40, a male-side conductor 41 connected to the inspection DC breaker 21A is projected, and on the right side of the rear end of the unit 23A (23N), the inspection AC output breaker 22A (22N). A conductor 42 connected to the power source side of the is protruded. Behind these conductors 40, 41, 42,
A female not-shown connecting part to which these conductors 40, 41, 42 are fitted is attached to the rear part of the boxes 30a, 30b, and these connecting parts are provided at the rear part of the boxes 30a, 30b. Not connected to a common conductor.

Above each conductor 40, 41, 42, each unit
Three fans 34, which discharge the cooling air warmed by a semiconductor element (not shown) housed inside 23A (23N) to the rear, are arranged side by side. Next, a procedure for inspecting each unit 23A (23N) in the power conversion device thus configured will be described.

Referring now to FIG. 1, the main AC input circuit breaker 3,
Main DC input breaker 4 and main AC input breaker 8 are ON,
Circuit breakers for other inspections 20A, 21A, 22A ... 20N, 21N, 22
It is assumed that N is also in the ON state and AC power is being supplied to the load 9. When the capacity of the load is ⅔ or less of the output capacity of the uninterruptible power supply, for example, it is possible to supply power to the load even if only the unit 23A is pulled out.

At this time, first, the inspection breaker 22A is turned off from the on state. This makes unit 23A
Turns off the inspection DC input circuit breaker 21A, and further turns off the inspection AC input circuit breaker 20A.

Finally, the connector 23 at the tip of the control cable 35 shown in FIG. 2 is pulled out from the connector 44 to disconnect the unit 23A from other units. Further, by pulling the handle 23a for pulling out the unit 23A shown in FIG. 3, the conductors 40, 41 and the conductor 42 of the unit 23A are pulled out from the female side connecting portion on the box side, respectively.
Is guided by the pull-out rail 32A and pulled out.

Then, the pulled-out unit 23A is removed from the box body 30b by a lifter, and the cooling fan 34 and the DC capacitor 6A are inspected and replaced if necessary. When this inspection / replacement is completed, it is stored again in the box 30b, the control cable 35 and the connector 44 are connected, and the AC input circuit breaker 20A for inspection is connected.
With the inspection breaker 21A turned on, the converter 5A,
Check the operating state of the inverter 7A. Finally, by turning on the inspection AC output circuit breaker 22A,
Power the load at 23A.

Similarly, the other units 23B ... 23N also operate the circuit breakers and units in the same order so that the cooling device inside the uninterruptible power supply and the direct current are supplied even while the load 9 is being supplied with power. Capacitors can be inspected and replaced.

Further, in the connection diagram shown in FIG. 1, when the number of units is four and the capacity of the load 9 is sufficient according to the initial plan, only four units are installed first and the capacity of the load 9 is set after the installation. It is possible to easily cope with the increase in the load capacity by adding the units 23E and 23N at the time of increase.

In the above embodiment, the power converter is
Although it has been described with respect to the uninterruptible power supply, for example, it may be a variable voltage variable frequency power supply, and in the above embodiment, the description has been given with respect to a unit in which the converter and the inverter are combined, but the converter and the inverter are different. It may be a unit.

[0038]

As described above, according to the present invention, in the power conversion device including the conversion unit including the converter and the inverter, and the detection / drive circuit for driving the conversion unit and detecting the voltage / current, the conversion unit and the detection unit are detected.・ Driving circuit is a multiple of the installed capacity
It is composed of a plurality of units, and this unit is housed in a box so that it can be pulled out in multiple stages, and the rear part of this unit is provided with a connection part and a cooling fan that are connected to the power supply side and the load side by inserting this unit. At the time of maintenance and inspection,
Since the plurality of units are drawn out in order to perform the work, it is possible to obtain the power conversion device that can perform the required work safely and easily without stopping the power supply to the load.

[Brief description of drawings]

FIG. 1 is a main circuit single wire connection diagram showing an embodiment of a power conversion device of the present invention.

FIG. 2 is a perspective view showing an embodiment of the power conversion device of the present invention.

FIG. 3 is a diagram showing a unit that is a component of the power conversion device of the present invention, in which (a) is a plan view and (b) is a front view.
(C) is a rear view and (d) is a right side view.

FIG. 4 is a main circuit single wire connection diagram showing an example of a conventional power conversion device.

FIG. 5 is a main circuit single wire connection diagram showing an example of a conventional power conversion device different from that of FIG.

[Explanation of symbols]

1 ... AC input power source, 2 ... Storage battery, 3 ... Main AC input circuit breaker, 4 ... Main DC input circuit breaker, 5A ... Converter, 6A ...
DC capacitor, 7A ... Inverter, 8 ... Main AC output circuit breaker, 9 ... Load, 10A ... Detection / drive circuit, 11A ... Cooling device, 20A (20N) ... Main AC input circuit breaker for inspection, 21A (21
N) ... DC input circuit breaker for inspection, 22A (22N) ... AC output circuit breaker for inspection, 23A (23N) ... Unit, 40, 41, 42 ...
Conductor, 34 ... fan.

Claims (1)

[Claims] 1. A power converter comprising a converter and a converter including an inverter, and a detection / drive circuit for driving the converter and detecting a voltage / current, wherein the converter and the detection / drive circuit have an installed capacity. This unit is composed of a plurality of units, and this unit is housed in a box so that it can be pulled out in multiple stages. The unit is inserted into the rear of this unit and connected to the power supply side and the load side, and the cooling section. An electric power converter comprising a fan for use.