JP2008228517A - Uninterruptible power supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an uninterruptible power supply device that can attain reduction in generation loss and longer service life for the components that constitute a converter part and an inverter part, while recovering from failures without problems, in feeding power to a load. <P>SOLUTION: The uninterruptible power supply device has a converter part 21, in which a plurality of converters are unitized and connected in parallel, and an inverter part 22 in which a plurality of inverters are unitized and connected in parallel. The input side of the inverter part 22 is connected to the DC output side of the converter part, while a storage battery 25 is connected to the DC output side of the converter part so as to be chargeable/dischargeable; and each converter unit in the converter part 21 and each inverter unit in the inverter part 22 are respectively individually subjected to operation stop control. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an uninterruptible power supply that supplies a stable power supply having a predetermined voltage and a predetermined frequency even when a commercial power supply is interrupted.

FIG. 4 is a configuration diagram of a conventional general uninterruptible power supply (UPS) system. Such an uninterruptible power supply includes a converter unit 11 that converts commercial AC power into DC, a storage battery 12 that stores electric power converted into DC, an inverter unit 13 that reversely converts DC into AC, and control and protection of the entire device. It is comprised by the control circuit part 14 which manages. When a power failure occurs in the commercial power supply, the converter unit 11 is stopped, DC power is supplied from the storage battery 12, and AC power is continuously supplied to the load by the inverter 13. When an internal failure occurs, it is detected by the control circuit and a stop command is output to the converter / inverter (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 9-252581

  In such a configuration, if a failure occurs in the apparatus, the converter or inverter is protected and stopped, so that the power supply to the load is hindered. Further, even if a failure is caused by a part of a product in a converter or an inverter, the entire uninterruptible power supply is stopped, and replacement / recovery measures are required. In addition, when selecting the equipment rating, converters and inverters with ratings that match the total capacity of all load facilities are selected. As a result, even when operated at light load, the entire UPS is in operation and all products are always in operation. There was a problem that power loss increased. In addition, since the loss to be consumed is released as heat, the rating selection of the air conditioner for cooling has also been affected.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an uninterruptible power supply capable of extending the service life and reducing generated loss of articles constituting a converter unit and an inverter unit and capable of recovering from a failure without hindering power supply to a load. It is in.

  The uninterruptible power supply apparatus of the present invention is a converter part in which a plurality of converters that convert AC to DC in a unit are unitized and connected in parallel, a storage battery that is connected to the DC output side of this converter part and can be charged and discharged, and A plurality of inverters for converting DC to AC in reverse are unitized and connected in parallel, the input side thereof is connected to the DC output side of the converter part, and the output side includes an inverter part connected to the load side, the converter The part and the inverter part are configured so that each converter unit and each inverter unit can be individually controlled to stop operation.

  In the present invention, each converter unit and each inverter unit may have an input part and an output part inserted and connected, and when the operation is stopped in units, the stop unit may be drawn out from the apparatus main body. .

  Further, in the present invention, the converter portion has a means for measuring the DC output current value, and obtains the required number of operation from the DC output current value and the rated value of each converter unit, and by comparison with the current operation number, It has control means for the converter part that performs increase / decrease control of the number of operating units.

  Further, in the present invention, the control means of the converter portion has a function of satisfying the DC output current value by starting the healthy converter unit that is stopped when the converter unit that is operating is stopped due to failure.

  In the present invention, the inverter portion has a means for measuring the AC output current value, and the required number of operating units provided with redundancy for one inverter unit from the AC output current value and the rated value of each inverter unit. And having an inverter partial control means for performing increase / decrease control of the number of operating units by comparison with the current number of operating units.

  Further, according to the present invention, the inverter partial control means activates a healthy converter unit that is stopped when the operating inverter unit is stopped by failure, and provides redundancy for one inverter unit with respect to the AC output current value. It has a function that satisfies the condition.

  According to the present invention, the converter portion and the inverter portion of the uninterruptible power supply are each divided into a plurality of unit configurations, and the number of units suitable for the load current are controlled to operate / stop, and the individual unit operation / Since it is possible to stop and remove the product, it is possible to extend the life of the product and reduce the generated loss, and it is possible to recover the failure without hindering the power supply to the load, further improving the reliability as an uninterruptible power supply. can do.

  Hereinafter, an embodiment of an uninterruptible power supply according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing the equipment configuration of the uninterruptible power supply in this embodiment. In this uninterruptible power supply apparatus, a converter circuit 21, a storage battery 25, and an inverter part 22 constitute a main circuit and supplies a stable power to a load 28. The converter part 21 is formed by connecting in parallel a plurality of converters CONV-1, CONV-2,. The storage battery 25 is connected to the DC output side of the converter portion 21 and is configured to be chargeable / dischargeable. The inverter portion 22 is connected in parallel to a plurality of unitized inverters INV-1, INV-2,... INV-n, each of which converts DC directly into alternating current, and the input side thereof is the DC output of the converter portion 21. The output side is connected to the load 28 side.

  Here, the converter part 21 and the inverter part 22 are respectively connected to each converter unit CONV-1, CONV-2,... CONV-n and each inverter unit INV-1, INV-2,. It is configured so that the operation stop control can be performed individually. In addition, each converter unit CONV-1, CONV-2,... CONV-n and each inverter unit INV-1, INV-2,. When the operation is stopped in units, the stop unit can be pulled out from the apparatus main body.

  The converter portion 21 has a DC output current value measuring means 23 and a converter portion control means 21C for increasing / decreasing the number of converter units CONV-1, CONV-2,. This control means 21C is a necessary operation of the converter unit that satisfies the DC output current value from the DC output current value of the converter portion 21 and the rated value of each converter unit CONV-1, CONV-2, ... CONV-n. Obtain the number of units, and increase / decrease the number of units in operation by comparing with the current number of units in operation. The converter partial control means 21C also has a function of starting a healthy converter unit that is stopped and satisfying the DC output current value when any of the converter units that are in operation is stopped due to failure.

  The inverter part 22 includes an AC output current value measuring means 24 and an inverter part control means 22C for increasing / decreasing the number of inverter units INV-1, INV-2,. Have. This control means 22C provided redundancy for one inverter unit from the AC output current value from the inverter portion 22 and the rated value of each inverter unit INV-1, INV-2, ... INV-n. Obtain the required number of operating units, and increase / decrease the number of operating units by comparing with the current operating number. Further, this inverter partial control means 22C, when any of the operating inverter units is stopped due to a failure, activates a healthy converter unit that is stopped to provide redundancy for one inverter unit with respect to the AC output current value. It also has the function of satisfying the raised state.

  As described above, the converter portion 21 and the inverter portion 22 have a plurality of units mounted in one uninterruptible power supply, and supply the necessary power to the load 28 by operating these units in parallel. To do. That is, the configuration can be changed to a necessary capacity by changing the number of units. The converter portion 21 and the inverter portion 22 have control means 21C and 22C, respectively, and can be operated and stopped as a single unit as will be described later. That is, it is possible to give selectivity to the operation / stop of the unit according to the actual load capacity condition and the unit failure information.

  Furthermore, each unit of the converter portion 21 and the inverter portion 22 is plug-in connected to the main circuit by the connector portion 26, and can be individually stopped and pulled out from the apparatus main body without stopping power transmission to the load. is there. That is, when exchanging the unit, the work can be performed without stopping the power transmission to the load.

  FIG. 2 shows an operation number control flow in the control means 21 </ b> C of the converter portion 21. In FIG. 2, first, the current value (DA) measured by the DC output current measuring unit 23 of FIG. 1 is captured (step 31). Next, the DC output current value (DA) is satisfied by dividing the DC output current value (DA) by the unit rated current values of the converter units CONV-1, CONV-2,... CONV-n. Therefore, the number of operating units required for this is calculated (step 32).

  The required number of operating units thus obtained is compared with the number of currently operating units (step 33). That is, the required number of operating units is subtracted from the current number of operating units. As a result, if the value is negative, the current number of operating units is insufficient, so that one additional converter unit is added (step 34). On the other hand, if the number is positive, the current number of operating units is excessive, so one converter unit is stopped (step 35).

  In this way, the required number of units is obtained from the measured DC output current value (DA), and the number of units required for the load is operated by constantly comparing this with the number of units currently operating. It becomes possible. For this reason, it becomes possible to reduce the deterioration of the converter unit and the power consumption loss without excessively operating the number of units when the load is light.

  In addition, even when a converter unit that is in operation is stopped due to a failure, it can be determined that the remaining number of operating units is insufficient with respect to the required number of operating units. Thus, it is possible to secure the necessary number of loads. Note that the shortage of direct current from when a unit failure occurs until another unit is operated is compensated by the storage battery 25. Therefore, it is possible to perform control to always secure units for a necessary direct current even when a unit failure occurs.

  FIG. 3 shows an operation number control flow in the control means 22 </ b> C of the inverter portion 22. In FIG. 3, first, the current value (AA) measured by the AC output current measuring unit 24 of FIG. 1 is captured (step 41). Next, by dividing this AC output current value (AA) by the rated current value of each unit of the inverter units INV-1, INV-2,... INV-n, and adding 1 to the redundant number, A required number of operating units satisfying the AC output current value (AA) and viewing the number of redundant operating units is calculated (step 42).

  The required number of operating units thus obtained is compared with the number of currently operating units (step 43). That is, the required number of operating units is subtracted from the current number of operating units. As a result, if it is negative, the current number of operating units is insufficient, so that one additional inverter unit is added (step 44). On the other hand, if it is positive, the current number of operating units is excessive, so one inverter unit is stopped (step 45).

  In this way, the required operating number including one redundant unit is obtained from the measured AC output current value (AA), and the load is made redundant by constantly comparing it with the number of currently operating units. It is possible to keep the number of units in operation. Therefore, it is possible to reduce the deterioration of the inverter unit and power consumption loss, and to ensure one redundant unit for the load capacity at all times. It becomes possible to do.

  In addition, even if the operating inverter unit fails and stops, it can be judged that the remaining number of operating units is insufficient with respect to the required number of operating units. Thus, it is possible to secure a necessary number of redundant loads. That is, even when a unit failure occurs, it is possible to ensure redundancy for one unit in addition to the necessary alternating current.

  Thus, since the converter part 21 and the inverter part 22 were divided | segmented into the some unit with the uninterruptible power supply device, it is possible to change a structure to a capacity | capacitance required for the load installation 28. FIG. Further, the stop location can be separated for each unit with respect to a part of the failure, and even when replacing the failed unit, the entire apparatus is not stopped, and the power supply to the load is not hindered. The number of units to be operated can be minimized according to the output DC current, and the number of units to be operated can always be controlled in the event of a unit failure. As a result, it is possible to reduce the number of products in operation, so that it is possible to extend the life of the products and reduce the power consumption loss.

It is a block diagram which shows one Embodiment of the uninterruptible power supply by this invention. It is a flowchart explaining operation | movement of the converter partial control means in one Embodiment same as the above. It is a flowchart explaining operation | movement of the inverter partial control means in one Embodiment same as the above. It is a block diagram explaining a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 Converter part 22 Inverter part 21C Converter part control means 22C Inverter part control means 23 DC output current measurement means 24 AC output current measurement means 25 Storage battery 26 Plug connection part 28 Load

Claims (6)

A converter part in which a plurality of converters each converting AC to DC are unitized and connected in parallel,
A storage battery that is connected to the DC output side of this converter and can be charged and discharged;
A plurality of inverters each for converting direct current into alternating current are unitized and connected in parallel, and their input side is connected to the DC output side of the converter part, and the output side includes an inverter part connected to the load side,
The uninterruptible power supply apparatus, wherein the converter part and the inverter part are configured so that the operation of each converter unit and each inverter unit can be controlled individually.   Each converter unit and each inverter unit has an input part and an output part inserted and connected, and when the operation is stopped in units, the stop unit can be pulled out from the apparatus main body. The uninterruptible power supply according to claim 1.   The converter section has a means for measuring the DC output current value, and obtains the required number of operating units from the DC output current value and the rated value of each converter unit. The uninterruptible power supply according to claim 1 or 2, further comprising control means for a converter portion for performing control.   The control means of the converter portion has a function of starting a healthy converter unit that is stopped and satisfying a DC output current value when a converter unit that is operating is stopped due to a failure. Uninterruptible power system.   The inverter part has a means for measuring the AC output current value, and obtains the required number of operating units with redundancy for one inverter unit from the AC output current value and the rated value of each inverter unit, The uninterruptible power supply according to claim 1 or 2, further comprising inverter partial control means for performing increase / decrease control of the number of operating units.   The inverter partial control means is a function that satisfies the state in which when the inverter unit in operation is stopped due to a failure, a sound converter unit that is stopped is started and the AC output current value is provided with redundancy equivalent to one inverter unit. The uninterruptible power supply according to claim 5.

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