JP2016136814A - Power conversion device and control method for power conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power conversion device and control method for the device, capable of suppressing occurrence of malfunction while reducing a system stop time.SOLUTION: A power conversion device 10 for converting power that is supplied from a power supply device and has a predetermined voltage, to power having a desired voltage differing from the predetermined voltage to supply the converted power to a load includes: a conversion unit 14 for converting input power having the predetermined voltage to power having the desired voltage to output the converted power; a sensor unit 15 for measuring a characteristic value on the power output from the conversion unit 14; and a control unit 18 for controlling the conversion unit 14's power conversion on the basis of the characteristic value measured by the sensor unit 15. The control unit 18 stops the conversion unit 14's power conversion, when a period of time in which the characteristic value is out of a predetermined range exceeds a predetermined threshold; and continues the conversion unit 14's power conversion, when the period of time is within the predetermined threshold.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a power conversion device and a method for controlling the power conversion device.

  A rectifier system that converts AC power supplied from commercial power into DC power of a desired voltage and supplies it to a load device is generally known. When the voltage of the DC power supplied from the rectifier system matches the voltage that can be handled by the load device, the DC power is directly supplied from the rectifier system to the load device.

  On the other hand, there may be a mismatch in voltage, such as when the voltage of the DC power supplied from the rectifier system is higher than the voltage that the load device can handle. In this case, a power conversion device such as a DC-DC converter that transforms the voltage of the DC power supplied from the rectifier system into a voltage that can be supported by the load device is provided between the rectifier system and the load device. The arrangement method is known (for example, refer to Patent Document 1).

Japanese Patent Application Laid-Open No. 09-065651

  The DC-DC converter device described in Patent Document 1 discloses a technique that enables constant voltage control in a wide input voltage range. However, a technique for dealing with a change in voltage on the output side of the DC-DC converter device is not disclosed.

  If an overload state occurs due to some cause on the output side of the DC-DC converter device, the voltage on the output side of the DC-DC converter device may decrease. For example, when a load device that exceeds the capacity of the DC-DC converter device is mistakenly connected to the DC-DC converter device, the voltage on the output side of the DC-DC converter device may decrease. Further, when the + terminal and the − terminal arranged at the output side of the DC-DC converter device, the output terminal of the DC-DC converter device, or the input terminal of the load device are close to each other, both terminals are used for some reason. It is conceivable that conduction occurs between the two and the voltage on the output side of the DC-DC converter device decreases.

  Generally, when the voltage on the output side of the DC-DC converter device decreases due to an overload state, the output of power from the DC-DC converter device is stopped, and control for protecting the DC-DC converter device is performed. Has been done.

  However, in the above-described control, the DC-DC converter device is frequently stopped, and a maintenance person rushes to the site to restart the load device to which power is supplied from the DC-DC converter device and the DC-DC converter device. There was a problem that the system stopped until it was done. On the other hand, if the DC-DC converter device does not stop, there is a problem that the DC-DC converter device and its peripheral devices may be defective due to heat generation in an overload state.

  The present invention has been made to solve the above-described problem, and provides a power conversion device and a method for controlling the power conversion device that can reduce the system stop time and suppress the occurrence of problems. For the purpose.

In order to achieve the above object, the present invention provides the following means.
A power conversion device according to a first aspect of the present invention is a power conversion device that converts power of a predetermined voltage supplied from a power supply device into a desired voltage having a value different from the predetermined voltage and supplies the converted voltage to a load device. A conversion unit that converts the input power of the predetermined voltage into power of the desired voltage and outputs the power, a sensor unit that measures a characteristic value related to the power output from the conversion unit, and a measurement by the sensor unit And a control unit that controls power conversion in the conversion unit based on the characteristic value that is set, and the control unit is configured to operate when a period during which the characteristic value is out of a predetermined range exceeds a predetermined threshold value. Stops conversion of power by the conversion unit, and continues conversion of power by the conversion unit when the period is within the predetermined threshold.

  The power conversion device control method according to the second aspect of the present invention is a power conversion method for converting power of a predetermined voltage supplied from a power supply device into a desired voltage having a value different from the predetermined voltage and supplying the power to a load device. A method for controlling an apparatus, comprising: a measuring step of receiving a power supply of a predetermined voltage and measuring a characteristic value related to the power of the desired voltage converted by a conversion unit; and a period during which the characteristic value is out of a predetermined range. A determination step for determining whether or not a threshold value has been exceeded, and a stop step for stopping the conversion of power by the conversion unit when it is determined that the period during which the characteristic value is outside the predetermined range has exceeded a predetermined threshold value; It is characterized by having.

  According to the power conversion device and the control method of the present invention, when the characteristic value related to the power output from the conversion unit is out of the predetermined range, the power conversion is performed when the time period out of the characteristic value is within the predetermined threshold. The power supply to the load device can be continued without stopping.

  On the other hand, when the above-described period exceeds a predetermined threshold, the conversion of power is stopped and the supply of power to the load device is stopped, so that the occurrence of problems due to the supply of power can be suppressed. Examples of the trouble due to the supply of electric power include a trouble such as a failure due to heat generated in the conversion unit or the load device.

  In the first aspect of the invention, the predetermined threshold is shorter than a period required from the occurrence of a short circuit to the release thereof in a wiring for supplying electric power disposed between the conversion unit and the load device. It is preferable.

  By setting the predetermined threshold in this way, it is possible to suppress the occurrence of defects. For example, when connecting the above-mentioned wiring to the terminal of the power converter or load device, if a tool or the like is accidentally dropped during the operation and it is short-circuited between + and-, the characteristic value falls from the predetermined range. Come off. At this time, in order to safely remove the tool, it is necessary to stop the power converter, and by setting a predetermined threshold shorter than the period required until the short circuit is released, a large current is generated in the converter and the tool. It is possible to suppress the occurrence of problems caused by continuing to flow.

In the first aspect of the invention, it is preferable that the predetermined threshold is longer than a period from when the characteristic value is out of the predetermined range until the load device stops.
By setting the predetermined threshold in this way, it becomes easy to stably supply power to the load device. For example, when an excessive number of load devices are connected to the capacity of the power conversion device, the characteristic value falls outside a predetermined range. At this time, by setting the predetermined threshold longer than the period until the load device stops, the load device is stopped before the conversion unit is stopped. Then, the load by the connected load device decreases, the characteristic value returns to a predetermined range, and the power supply to the load device can be maintained.

  In the first aspect of the invention, the characteristic value is a voltage, and the control unit, when a period during which the characteristic value is smaller than a lower threshold value of the predetermined range exceeds the predetermined threshold value, It is preferable that the conversion of power by the conversion unit is stopped and the conversion of power by the conversion unit is continued when the period is within the predetermined threshold. By using the voltage as the characteristic value in this way, a measuring device such as a voltmeter can be used as the sensor unit, and the characteristic value can be easily measured.

  In the first aspect of the invention, the characteristic value is a current, and the control unit determines that the period when the characteristic value is larger than the upper threshold value of the predetermined range exceeds the predetermined threshold value. It is preferable to stop the power conversion by the conversion unit and continue the power conversion by the conversion unit when the period is within the predetermined threshold. By using the current as the characteristic value in this way, a measuring device such as an ammeter can be used as the sensor unit, and the characteristic value can be easily measured.

  In the first aspect of the present invention, an output-side blocking unit capable of blocking an inflow of electric power to the conversion unit by control by the control unit is further provided on the load device side than the sensor unit, and the conversion unit It is preferable that a plurality of conversion units having at least the sensor unit and the output-side blocking unit are arranged in parallel.

  By providing a plurality of conversion units in this way, for example, even if a failure occurs in one conversion unit, power can be supplied from the remaining conversion units to the load device. For example, by providing redundancy to the number of conversion units, power can be supplied more stably.

  In addition, by providing the output-side blocking unit, it is possible to suppress the power output from other conversion units from flowing into the conversion unit in which the problem has occurred even if the conversion unit has a problem. In other words, when the control unit detects that a malfunction has occurred in the conversion unit, the control unit performs control to block the inflow of power to the output-side cutoff unit corresponding to the conversion unit. Thereby, it can suppress that the electric power output from the other conversion unit wraps around in the conversion part which generate | occur | produced the malfunction.

  In the first aspect of the present invention, it is preferable that a distribution unit having a power storage unit capable of charging and discharging part of the electric power of the desired voltage is further provided on the load device side of the conversion unit.

  By providing the distribution unit having the power storage unit in this manner, for example, when a power fuse that prevents inflow of excessive current is provided in the load device, the above-described fuse is utilized by using the power stored in the power storage unit. Can be melted.

  According to the power conversion device and the method for controlling the power conversion device of the present invention, when the characteristic value related to the power output from the conversion unit is out of the predetermined range, the power conversion is performed when the time period out of the characteristic value is within the predetermined threshold. Will not stop. Therefore, there is an effect that the supply of power to the load device is continued, in other words, the system stop time can be shortened and the occurrence of problems can be suppressed.

It is a model diagram explaining the whole structure containing the power converter device which concerns on one Embodiment of this invention. It is a schematic diagram explaining the structure of the power converter device of FIG. It is a flowchart explaining the control in the power converter device of FIG. It is a graph explaining the relationship between the electric current in the electric power output from the power converter device of FIG. 1, and a voltage. It is a graph explaining the length of predetermined threshold value PT.

  A power converter according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the power conversion device 10 of the present embodiment supplies DC power of a desired voltage (48 V in the present embodiment) to an ICT device (load device) 40 together with a rectifier (power supply device) 30. is there. Note that the load device to which the power conversion device 10 supplies power may be the ICT device 40 as described above, or may be a device that consumes power, such as other electronic devices, and is particularly limited. is not.

  The rectifier 30 receives commercial power (three-phase AC, 200 V) supplied from the system power 35 and outputs 200 V DC power. The rectifier 30 is provided with a storage battery 31 capable of charging and discharging DC power. In addition, as the rectifier 30, the well-known AC-DC converter etc. which convert alternating current power into direct-current power can be used, and the form in particular is not limited. Moreover, as the storage battery 31, what is necessary is just to be able to charge and discharge, and the kind is not specifically limited.

  The power conversion device 10 functions as a DC-DC converter that converts 200V DC power supplied from the rectifier 30 into 48V DC power and supplies it to the ICT device 40. In the present embodiment, description will be made by applying to an example in which a distribution board (distribution unit) 21 is independently arranged between the power conversion apparatus 10 and the ICT apparatus 40. It may be arranged integrally with the conversion device 10 and is not particularly limited.

  As shown in FIG. 2, the power conversion device 10 is mainly provided with a plurality of conversion units 11 and a control unit 18. The conversion unit 11 is mainly provided with an input filter 12, an input side blocking unit 13, a conversion unit 14, a sensor unit 15, an output side blocking unit 16, and an output filter 17.

  The conversion unit 11 is arrange | positioned in parallel in the power converter device 10, and each converts 200V DC power supplied from the rectifier 30 into 48V DC power. In FIG. 2, one conversion unit 11 is shown for ease of explanation, but actually, a plurality of conversion units 11 are arranged in parallel.

  The number of conversion units 11 is preferably such that the total capacity of each conversion unit 11 is larger than the total load of the ICT device 40 connected to the power conversion device 10. Furthermore, it is more preferable that the total of the capacities of the respective conversion units 11 is the number obtained by adding one unit to the number of units equal to the total load of the ICT device 40 connected to the power conversion device 10.

  The control unit 18 controls power conversion in the conversion unit 11. The control unit 18 is input with measurement signals such as voltage and current in 200 V DC power supplied to the conversion unit 11 and 48 V DC power output from the conversion unit 11. Moreover, the voltage signal measured by the sensor part 15 mentioned later is also input.

  The input filter 12 is a filter disposed on the input side of the conversion unit 14 and removes components that may cause problems with power conversion from the 200 V DC power supplied to the conversion unit 14. .

  The input side blocking unit 13 is disposed on the input side of the conversion unit 14 and prevents a large current exceeding the allowable range of the conversion unit 14 from flowing into the conversion unit 14. In the present embodiment, description will be made by applying to an example in which the input-side blocking unit 13 is a power fuse that prevents inflow of a large current by fusing, but other elements that exhibit the same function such as a semiconductor switch are used. May have been.

  The conversion unit 14 is a DC-DC converter that converts 200V DC power supplied from the rectifier 30 into 48V DC power. The power conversion in the conversion unit 14 is controlled by a control signal input from the control unit 18. As the conversion unit 14, a known DC-DC converter configuration can be used, and the type and configuration are not particularly limited.

  The sensor unit 15 is disposed between the conversion unit 14 and the output-side blocking unit 16 and measures the voltage of 48V DC power supplied from the conversion unit 14. A voltage measurement signal measured by the sensor unit 15 is output to the control unit 18 described above. As the sensor unit 15, a known measuring unit can be used as long as it is a sensor that measures voltage, and the type and form of the sensor element are not limited.

  The output side blocking unit 16 is disposed on the output side of the conversion unit 14 and prevents a large current from flowing into the conversion unit 14 (backflow) based on a control signal input from the control unit 18. . In the present embodiment, description will be made by applying to an example in which the output-side blocking unit 16 is a semiconductor switch that performs a blocking operation by a control signal. However, the present invention is not limited to a semiconductor switch, and other switches that perform a blocking operation by a control signal. May be used.

  The output filter 17 is a filter disposed on the output side of the conversion unit 14 and removes components that may affect the operation of the ICT device 40 from the 48 V DC power supplied to the ICT device 40. is there.

  As the above-described input filter 12 and output filter 17, those having a known configuration can be used as long as they have filter performance corresponding to the characteristics of the conversion unit 14, the ICT device 40, and the like. The type is not limited.

  The distribution board 21 distributes 48V DC power supplied from the power converter 10 to the plurality of ICT devices 40. In FIG. 1, an example in which one ICT device 40 is connected to the distribution board 21 is displayed for easy explanation. A capacitor (power storage unit) configured to charge a part of 48V DC power supplied to the ICT device 40 to the distribution board 21 and supply the charged power to the ICT device 40 22 is provided.

Next, the operation and control in the power conversion device 10 having the above configuration will be described.
When the conversion from 200V DC power to 48V DC power is started in the power conversion device 10, the control unit 18 converts the 48V converted 48V output from the sensor unit 15 as shown in the flowchart of FIG. Processing for obtaining a measurement signal indicating the measurement voltage of the DC power is performed (S10: measurement step).

  When acquiring the measurement signal, the control unit 18 performs a process of determining whether or not the period P during which the value of the measurement voltage indicated by the measurement signal is lower than the lower threshold (predetermined range) TL exceeds the predetermined threshold PT. (S20: Determination step). In the present embodiment, description will be made by applying to an example in which the value of the lower threshold value TL is 30V and the predetermined threshold value PT is 1 second. The value of the lower threshold value TL is set to an appropriate value according to the specification of the target device that receives power supply from the power conversion device 10, and may be a voltage higher than the above-described 30V. However, it may be a low voltage and is not particularly limited.

Here, the relationship between the voltage and current of the DC power supplied from the power converter 10 will be described with reference to FIG. The vertical axis of the graph in FIG. 4 is voltage, and the horizontal axis is current.
The power conversion device 10 supplies power of a voltage (48V) determined with a predetermined accuracy when the current ranges from 0 to I1. When the current is in the range from I1 to less than I2, the voltage decreases linearly to V2 (for example, 41 V), and when the current reaches I2, the voltage decreases toward 0. Therefore, for example, when a short circuit occurs somewhere between the power conversion device 10 and the ICT device 40, the current supplied from the power conversion device 10 increases to I2.

Further, the predetermined threshold PT will be described with reference to FIG. The horizontal axis of the graph in FIG. 5 indicates time, and the origin indicates the time when the value of the measured voltage falls below the lower threshold value TL.
In the present embodiment, description will be made by applying to an example in which the predetermined threshold PT is set to about 1000 ms. By setting in this way, the predetermined threshold value PT is reduced when the excessive number of ICT devices 40 are connected to the capacity of the power conversion device 10 as shown in FIG. It becomes longer than the period PT2 (several tens of ms) from when the value falls below the side threshold value TL to when the ICT device 40 stops. Furthermore, in the connection work of the wiring which supplies the electric power arrange | positioned between the power converter device 10 and the ICT apparatus 40, it becomes shorter than the period PT1 (several tens of seconds) required from the occurrence of a short circuit to the release thereof.

  Returning to FIG. 3, when it is determined that the period P lower than the lower threshold value TL exceeds the predetermined threshold value PT (in the case of YES), the control unit 18 stops power conversion with respect to the conversion unit 14. A process of outputting a control signal is performed (S30: stop step).

  In the determination process of S20, when it is determined that the period P that is lower than the lower threshold value TL is within the predetermined threshold value PT (in the case of NO), the control unit 18 performs a process of continuing the power conversion by the conversion unit 14. Perform (S40).

  When the process of S30 or the process of S40 is performed, the control unit 18 returns to S10 again and repeats the above process. This repetition may be performed continuously or may be performed discretely at a predetermined time interval, and is not particularly limited.

  In addition, the ICT device 40 is provided with a power fuse that prevents inflow of excess current by fusing when the supplied 48V DC power current becomes excessive. When the power conversion device 10 is stopped for some reason, the voltage of the supplied DC power may decrease and the current may increase (see FIG. 4).

  In this case, if the capacitor 22 provided in the distribution board 21 is not provided, the electric power necessary to blow the power fuse is not supplied, and an excessive current may be supplied to the ICT device 40. There is. On the other hand, when the capacitor 22 is provided on the distribution board 21, electric power necessary to blow the power fuse is supplied, and the power fuse can be easily blown.

  According to the power conversion device 10 having the above configuration, when the voltage of the DC power of 48V output from the conversion unit 14 is lower than the lower threshold TL, the power is supplied when the lower period P is within the predetermined threshold PT. The power supply to the ICT device 40 is continued without stopping the conversion.

  On the other hand, when the above-described period P exceeds the predetermined threshold value PT, the power conversion is stopped and the power supply to the ICT device 40 is stopped. . That is, it is possible to supply stable power regardless of voltage fluctuation on the ICT device 40 side, and it is possible to suppress the occurrence of defects. Here, as a malfunction due to the supply of power, for example, a malfunction such as a failure due to heat generated in the conversion unit 14 or the ICT device 40 can be exemplified.

  By making the length of the predetermined threshold PT about 1000 ms, it becomes easy to stably supply power to the ICT device 40. For example, when an excessive number of ICT devices 40 are connected to the capacity of the power conversion device 10, the voltage of 48V DC power falls below the lower threshold value TL. At this time, by setting the predetermined threshold value PT longer than the period P until the ICT device 40 stops, the ICT device 40 is stopped before the conversion unit 14 is stopped. Then, the load by the connected ICT device 40 decreases, and the voltage of 48V DC power returns to the lower threshold value TL or more, and the power supply to the ICT device 40 can be maintained.

  Furthermore, for example, when the above-mentioned wiring is connected to the terminal of the power conversion device 10 or the ICT device 40, if a tool or the like is accidentally dropped during operation and it is short-circuited between + and-, 48V The voltage of the DC power is below the lower threshold value TL. At this time, in order to remove the tool safely, it is necessary to stop the power conversion device 10, and by setting the predetermined threshold value PT shorter than the period required for releasing the short circuit, the conversion unit 14 and the tool are large. It is possible to suppress the occurrence of problems due to the continued flow of current.

  By providing a plurality of conversion units 11, for example, even if a failure occurs in one conversion unit 11, power can be supplied from the remaining conversion units 11 to the ICT device 40. Further, by providing redundancy to the number of conversion units 11, power can be supplied more stably.

  In addition, by providing the output-side blocking unit 16, even if a malfunction occurs in the conversion unit 14, it is possible to suppress that the power output from the other conversion unit 11 wraps around the conversion unit 14 in which the malfunction has occurred. That is, when the control unit 18 detects that a problem has occurred in the conversion unit 14, the control unit 18 controls the output side blocking unit 16 corresponding to the conversion unit 14 to block power inflow. Thereby, it can suppress that the electric power output from the other conversion unit 11 wraps around in the conversion part 14 which generate | occur | produced the malfunction.

  In the above-described embodiment, the sensor unit 15 is described as being applied to an example of a sensor that measures voltage. However, the sensor unit 15 is a sensor that measures current in addition to a sensor that measures voltage. Also good.

  In this case, in the determination process of S20, a process of determining whether or not the period P during which the value of the measurement current indicated by the measurement signal exceeds the upper threshold (predetermined range) TU has exceeded the predetermined threshold PT is performed. When it is determined that the period P exceeding the upper threshold TU exceeds the predetermined threshold PT (in the case of YES), the process proceeds to step S30, and when the period P exceeding the upper threshold TU is determined to be within the predetermined threshold PT If (NO), the process proceeds to step S40.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, description has been made by applying to an example in which 200V DC power is converted to 48V DC power. However, the voltage value of power input to the power conversion device 10 or the voltage of output power is described. The value may be other values and is not particularly limited.

  DESCRIPTION OF SYMBOLS 10 ... Power converter, 11 ... Conversion unit, 18 ... Control part, 14 ... Conversion part, 15 ... Sensor part, 16 ... Output side interruption | blocking part, 21 ... Distribution board (distribution part), 30 ... Rectifier (Power supply) Device), 40 ... ICT device (load device), S10 ... measurement step, S20 ... determination step, S30 ... stop step

Claims (8)

A power conversion device that converts power of a predetermined voltage supplied from a power supply device into a desired voltage having a value different from the predetermined voltage and supplies the converted voltage to a load device,
A converter that converts the input power of the predetermined voltage into the power of the desired voltage and outputs the power;
A sensor unit for measuring a characteristic value related to the power output from the conversion unit;
Based on the characteristic value measured by the sensor unit, a control unit for controlling the conversion of power in the conversion unit,
Is provided,
The control unit stops conversion of power by the conversion unit when a period in which the characteristic value is out of a predetermined range exceeds a predetermined threshold, and when the period is within the predetermined threshold, A power converter characterized by continuing the conversion of power by the converter.   The said predetermined threshold value is shorter than the period required from generation | occurrence | production of a short circuit to the cancellation | release in the wiring which supplies the electric power arrange | positioned between the said conversion part and the said load apparatus. Power conversion device.   The power converter according to claim 1, wherein the predetermined threshold is longer than a period from when the characteristic value is out of the predetermined range until the load device stops. The characteristic value is a voltage,
When the period during which the characteristic value is smaller than the lower threshold value of the predetermined range exceeds the predetermined threshold value, the control unit stops power conversion by the conversion unit, and the period is the predetermined value. The power conversion device according to any one of claims 1 to 3, wherein the conversion of the power by the conversion unit is continued when the value is within the threshold value. The characteristic value is current,
When the period during which the characteristic value is greater than the upper threshold value of the predetermined range exceeds the predetermined threshold value, the control unit stops power conversion by the conversion unit, and the period is the predetermined value. The power conversion device according to any one of claims 1 to 3, wherein the conversion of the power by the conversion unit is continued when the value is within a threshold value. On the load device side of the sensor unit, an output side blocking unit capable of blocking the inflow of electric power to the conversion unit by control by the control unit is further provided,
6. The power conversion device according to claim 1, wherein a plurality of conversion units including at least the conversion unit, the sensor unit, and the output-side blocking unit are arranged in parallel.   The power conversion device according to claim 6, further comprising a distribution unit including a power storage unit capable of charging and discharging a part of the electric power of the desired voltage on the load device side of the conversion unit. . A method for controlling a power conversion device that converts power of a predetermined voltage supplied from a power supply device into a desired voltage having a value different from the predetermined voltage and supplies the converted voltage to a load device,
A measurement step of receiving a power supply of a predetermined voltage and measuring a characteristic value related to the power of the desired voltage converted by the conversion unit;
A determination step of determining whether or not a period during which the characteristic value falls outside the predetermined range exceeds a predetermined threshold;
When it is determined that the period during which the characteristic value is outside the predetermined range has exceeded a predetermined threshold, a stop step of stopping the conversion of power by the conversion unit;
A method for controlling a power conversion apparatus comprising:

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