JP6532285B2 - Rectification device - Google Patents

Description

  The present invention relates to a rectifying device, and more particularly to a rectifying device used in a DC power supply system that supplies power from a storage battery to a communication facility at the time of a power failure.

  The electricity charge of the power purchased from the power company (purchased power) consists of the basic charge and the electricity charge. Among these, since the basic charge is a charge that is determined according to the contract power, it is possible to suppress the required contract power and reduce the basic charge by suppressing the purchased power at the peak when the power is required most instantaneously. It is possible (for example, refer to the following patent document 1). This applies to the power consumption of communication equipment including the radio base station.

  In the power supply system of the communication facility, as shown in FIG. 1, AC power from the commercial power source 1 (that is, power purchased from a power company) is converted by the rectifier 2 into DC power. The DC power from the rectifier 2 is supplied to the communication device 3 as a load (AR1). Further, the storage battery 4 is charged by the DC power from the rectifier 3 (AR2). The rectifier 2, the communication device 3 and the storage battery 4 are directly connected by, for example, a 48V bus (shown conceptually as node N in FIG. 1), and while the rectifier 3 is operating, the storage battery 4 is in a floating charge state. At the time of a power failure, the AC power from the commercial power source 1 can not be used, so the power from the storage battery 4 is supplied to the communication device 2.

JP, 2013-143867, A

  In the power supply system described above, the purchased power depends on the magnitude of the DC power output from the rectifier 2, but the magnitude of the DC power output from the rectifier 2 depends on the power consumption of the communication device 3 and the charge and discharge of the storage battery 4. It depends on the power. Then, in the above-described power supply system, at the time of power recovery immediately after recovery from the power failure, power consumption of the communication device and charging power of the storage battery are both increased, and a peak of purchased power may occur.

  The power consumption of the communication device increases at the time of power recovery because the temperature of the room is rising due to the heat generated from the communication device during a power failure, and at the time of power recovery, the air conditioner is operated with a high cooling function It is necessary to increase the power consumption of the air conditioner. Moreover, the reason that the charging power of the storage battery is large at the time of recovery is that the charging rate (SOC: State Of Charge) of the storage battery is decreasing due to discharge at the time of a power failure, and at the time of recovery, the SOC of the storage battery is restored accordingly It is necessary to charge the storage battery.

  The present invention has been made in view of the above problems, and in a direct current power supply system that supplies power from a storage battery to a load to a communication facility at the time of a power failure, rectification is capable of suppressing the peak of purchased power at the time of power recovery. It aims at providing an apparatus.

  The rectification device according to one aspect of the present invention is a rectification device used for a DC power supply system that supplies power from a storage battery to a load that is communication equipment when a power failure occurs in the AC power network, and the power failure occurs in the AC power network. When the AC power grid receives AC power from the AC power network to convert it into DC power and outputs the converted DC power toward the load and the storage battery, and when the AC power grid recovers, And control means for limiting the number of operating rectifier units.

  In the rectifier, the AC power from the AC power network is converted into DC power, and the number of operating the plurality of rectifier units outputting toward the load and the storage battery is limited at the time of power recovery. This limits the magnitude of AC power received from the AC power network by the plurality of rectifier units, so that the peak of purchased power (for example, power purchased from a power company via the AC power network) at the time of power recovery It can be suppressed.

  The control means may limit the number of operating the plurality of rectifier units so that the power output from the plurality of rectifier units toward the load and the storage battery does not exceed the predetermined power at the time of power recovery. This makes it possible to prevent the purchased power at the time of power recovery from exceeding the predetermined power (for example, the contract power).

  The control means may release the restriction on the number of operating the plurality of rectifier units when the current flowing from the plurality of rectifier units toward the load and the storage battery falls below a predetermined current. Thereby, the restriction of the number of operating the plurality of rectifier units can be canceled at an appropriate timing.

  The control means may limit the number of operating rectifier units so that the charging rate of the storage battery reaches a predetermined charging rate within a predetermined period of time after the recovery of the AC power network. Thereby, after the power recovery, the charging rate of the storage battery can be recovered within a predetermined period.

  In the rectifying device, the control means is based on a storage unit that stores power consumption of the load when no power failure occurs, a measurement unit that measures discharge power of the storage battery at the time of the power failure, and a measurement result by the measurement unit. Based on the calculation unit for calculating the charging rate of the storage battery at the end of the power failure, the power consumption of the load stored in the storage unit, the charging rate of the storage battery at the end of the power failure calculated by the computing unit, the predetermined charging rate, and the predetermined period And an adjusting unit that adjusts the number of operating rectifier units so that the charging rate of the storage battery reaches the predetermined charging rate within a predetermined period. In this way, the number of operating rectifier units can be appropriately adjusted so that the charging rate of the storage battery reaches the predetermined charging rate within the predetermined period.

  According to the present invention, it is possible to suppress the peak of purchased power at the time of power recovery in a DC power supply system that supplies power from a storage battery to a load at the time of a power failure.

It is a figure which shows schematic structure of the conventional DC-power-supply system. It is a figure which shows schematic structure of the rectifier concerning this embodiment. It is a figure which shows the hard block structure of a control part. It is a flowchart which shows an example of the process performed by a rectifier. It is a timing chart which shows operation of a direct-current power supply system notionally.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols and redundant description will be omitted.

  FIG. 2 is a view showing a schematic configuration of a DC power supply system 100 provided with the rectifier 10 according to the embodiment. The DC power supply system 100 includes the rectifying device 10 and the storage battery 4, and supplies power from the storage battery 4 to the communication device 3 when a power failure occurs in the commercial power supply 1.

  The DC power supply system 100 operates differently at the time of a power failure and at the time when it is not. At the time of power failure, a power failure occurs and power from the AC power network (power from the commercial power source 1) can not be used. The time when no power failure has occurred may be referred to as "normal time" hereinafter. The power from the commercial power source 1 is referred to as "purchased power Pu" because it is power that the DC power supply system 100 purchases from a power company or the like.

  The communication device 3 is a load that operates by receiving power, and is, for example, a communication facility such as a wireless base station. Since the communication device 3 generates heat, the communication device 3 is provided with an air conditioner (not shown). The power consumption of the air conditioner is included in the power consumption Pload of the communication device 3.

  In normal times, the power consumption Pload of the communication device 3 is covered by the output power Prc from the conversion unit 20 described later. On the other hand, at the time of a power failure, the power consumption Pload of the communication device 3 is covered by the power from the storage battery 4 (discharge power Pd described later).

  The power consumption Pload of the communication device 3 particularly increases at the time of power recovery for a while after the power failure recovers. That is, at the time of power recovery, a peak of the power consumption Pload of the communication device 3 may occur.

  Storage battery 4 is used, for example, to charge purchased power Pu. The power charged in the storage battery 4 is referred to as "charging power Pc". Further, the storage battery 4 supplies power to the communication device 3 by discharging, particularly at the time of a power failure. The electric power which the storage battery 4 discharges is called "discharge electric power Pd."

  At the time of a power failure, since the power consumption Pload of the communication device 3 is covered by the discharged power Pd from the storage battery 4, the SOC of the storage battery 4 decreases. In addition, at the time of power recovery, charging of storage battery 4 is performed to recover the lowered SOC. That is, the charging power Pc of the storage battery 4 is mainly generated at the time of power recovery and also increases.

  The rectifying device 10 is a power conversion device that converts AC power into DC power and outputs the DC power. The rectifying device 10 is electrically connected to the communication device 3 and the storage battery 4, converts it into AC power from the commercial power source 1, and outputs it to the communication device 3 and the storage battery 4. The rectifier 10 includes terminals T1 to T3, a converter 20, and a controller 30.

  The terminal T1 is an input terminal to which AC power (purchased power Pu) is input, and is connected to the commercial power supply 1. The terminal T2 is an output terminal for outputting DC power (power consumption Pload), and is connected to the communication device 3. The terminal T3 is an input / output terminal that receives DC power (discharge power Pd) or outputs DC power (charge power Pc), and is connected to the storage battery 4. Communication device 3 and storage battery 4 are electrically connected via terminals T1 and T2.

  The conversion unit 20 is a portion (AC / DC conversion unit) that converts AC power (purchased power Pu) input to the terminal T1 into DC power (output power Prc). Conversion unit 20 includes rectifier units 21-25. The rectifier units 21 to 25 are juxtaposed between the terminal T1 and the terminals T2 and T3. The rectifier units 21 to 25 receive the AC power (purchased power Pu) from the commercial power source 1 at normal times (that is, when no power failure occurs), convert the DC power into DC power (output power Prc). ) Is output to the communication device 3 and the storage battery 4. The output (power or current) of each of the rectifier units 21-25 may be fixed. The rectifier unit 21 is configured by combining, for example, a rectifier circuit and a voltage conversion circuit (boost circuit or high voltage circuit). The same applies to the rectifier units 22-25. Although five rectifier units 21 to 25 are shown in the example shown in FIG. 1, the number of rectifier units is not limited to this.

  The control unit 30 is a part (control means) that controls the conversion unit 20. The control unit 30 can control the rectifier units 21 to 25 included in the conversion unit 20 individually. For example, operation / stop of the rectifier units 21 to 25 (that is, whether to operate the rectifier units 21 to 25) is controlled by the control unit 30. Details of each element included in the control unit 30 will be described later.

  Here, the hardware configuration of the control unit 30 will be described with reference to FIG. As shown in FIG. 3, the control unit 30 physically includes one or more central processing units (CPUs) 41, a random access memory (RAM) 42 as a main storage device, and a read only memory (ROM) 43. Hardware such as a communication module 44 which is a data transmission / reception device, an auxiliary storage device 45 such as a semiconductor memory, an input device 46 which accepts user input such as a control panel (including operation buttons) or a touch panel, and an output device 47 such as a display Can be configured as a computer comprising The function of the control unit 30 is, for example, by reading one or a plurality of predetermined computer software (programs) on hardware such as the CPU 41, the RAM 42, and the like, under the control of the CPU 41, the communication module 44, the input device 46, This can be realized by operating the output device 47 and reading and writing data in the RAM 42 and the auxiliary storage device 45.

  In the DC power supply system 100, the purchased power Pu changes in accordance with the magnitude of the output power Prc of the conversion unit 20 (purchased power Pu = output power Prc when there is no conversion loss of the conversion unit 20), The magnitude of the output power Prc is determined by the power consumption Pload of the communication device 3 and the charge power Pc or the discharge power Pd of the storage battery 4. As described above, since the power consumption Pload of the communication device 3 and the charge power Pc of the storage battery 4 both increase at the time of power recovery, a peak of the purchased power Pu may occur.

  Therefore, control for suppressing the peak of purchased power Pu at the time of power recovery in DC power supply system 100 is realized by rectifying device 10.

  Specifically, the controller 30 limits the number of operating the plurality of rectifier units 21 to 25 at power recovery. The operating number indicates the number of rectifier units performing an operation to convert the purchased power Pu into the output power Prc. Limiting the number of operating units means reducing the number of operating units from the current number.

  The control unit 30 limits the number of operating the rectifier units 21 to 25 so that the output power Prc output from the rectifier units 21 to 25 to the communication device 3 and the storage battery 4 does not exceed a predetermined power at power recovery. .

  When the current Irc flowing from the rectifier units 21 to 25 toward the communication device 3 and the storage battery 4 falls below a predetermined current, the control unit 30 releases the restriction on the number of operating the rectifier units 21 to 25.

  After power recovery, control unit 30 limits the number of operating rectifier units 21 to 25 such that the SOC of storage battery 4 reaches a predetermined SOC within a predetermined period.

  In order to realize the control as described above, for example, control unit 30 includes storage unit 31, measurement unit 32, calculation unit 33, and adjustment unit 34.

  The storage unit 31 is a portion that stores various information necessary for control of the control unit 30. In particular, the storage unit 31 stores the power consumption Pload (power consumption Pload1 at normal time) of the communication device 3 when no power failure occurs. The normal power consumption Pload1 is calculated by, for example, a calculation unit 33 described later.

  The measurement unit 32 is a part that measures the discharged power Pd of the storage battery 4 at the time of a power failure. For example, measurement unit 32 detects a current value flowing from conversion unit 20 toward communication device 3 using current sensor 32a, and measures discharge power Pd based on the current value. More specifically, measuring unit 32 integrates discharge power Pd by integrating a value (power value) obtained by multiplying the detected current value by a voltage value (for example, the voltage value of terminal T2 detected by voltage sensor 32b). Can be measured. The measuring unit 32 can also detect a change (for example, a decrease) in the current value by using the current sensor 32a.

  The calculating unit 33 is a part that calculates the SOC of the storage battery 4 at the end of the power failure based on the measurement result by the measuring unit 32. For example, calculation unit 33 uses the fact that discharge power Pd is supplied from storage battery 4 to communication device 3 at the time of power failure, and based on the integrated value of the current value measured by measurement unit 32, etc. The SOC of the storage battery 4 is calculated. Further, the calculator 33 calculates the value of the power consumption Pload of the communication device 3. For example, the calculating unit 33 obtains an average value of current values measured by the measuring unit 32 at normal times, and calculates the power consumption Pload1 at normal time based on the average value of the currents and the like. The calculated normal power consumption Pload1 is stored in the storage unit 31.

  The adjustment unit 34 uses the normal power consumption Pload1 stored in the storage unit 31, the SOC of the storage battery 4 at the end of the power failure calculated by the calculation unit 33 (more specifically, the free capacity obtained based on the SOC), Based on the predetermined SOC described above and the predetermined period described above, the number of operating rectifier units 21 to 25 is adjusted so that the SOC of the storage battery 4 reaches the predetermined SOC within the predetermined period.

  For example, the output of each of the rectifier units 21 to 25 (here, the current value will be described) is 100A, the current corresponding to the power consumption Pload of the communication device 3 is 190A, and the free capacity of the storage battery 4 is 200Ah. A case will be described where it is required that the storage battery 4 be fully charged (that is, the predetermined SOC in this case is 100%) within 20 hours from that (that is, the predetermined period in this case is 20 hours). In this case, if the charging current to the storage battery 4 is 10 A or more, the charging time will be within 20 hours, so that the number of rectifier units to be operated is two (for example, the rectifier unit 21 and the rectifiers It is sufficient to decide as unit 22). At this time, when all the rectifier units 21 to 25 are operated, the charging power Pc of the storage battery 4 is large, and the outputs of the rectifier units 21 to 25 may be very large (at most 500 A). By operating only the unit 21 and the rectifier unit 22, it is possible to suppress the peak current to 200 A. If the power is used instead of the current, the number of operating the rectifier units 21 to 25 is determined and operated so that the output power Prc of the rectifier units 21 to 25 does not exceed the predetermined power.

  FIG. 4 is a flowchart showing an example of processing executed by the control unit 30. The processing of this flowchart is executed at the time of power recovery.

  First, control unit 30 calculates the SOC of storage battery 4 at the end of the power failure (step S1). This process is performed by the calculation unit 33 as described above.

  Next, the control unit 30 determines the number of operating the rectifier units 21 to 25 so that the output power Prc of the rectifier units 21 to 25 does not exceed the predetermined power (step S2). This process is performed by the adjustment unit 34 as described above.

  Next, the control unit 30 limits the number of operating the rectifier units 21 to 25 to operate the rectifier units 21 to 25 (step S3). This process is performed by the adjustment unit 34 as described above.

  And control part 30 judges whether a rectifier output current is less than a threshold (Step S4). For example, the measurement unit 32 executes this process based on the current value detected by the current sensor 32a.

  If the rectifier output current is less than the threshold in step S4 (step S4: YES), the control unit 30 releases the restriction on the number of operating rectifier units 21 to 25 (step S5), and ends the processing of the flowchart. This process is performed by the adjustment unit 34 as described above. If the rectifier output current is equal to or more than the threshold (step S4: NO), the control unit 30 returns the process to step S4 after waiting for a predetermined time (step S6).

  FIG. 5 is a timing chart conceptually showing the operation of DC power supply system 100. Referring to FIG. In FIG. 5, the purchased power of the DC power supply system 100 realized by the control of the control unit 30 (that is, the output power Prc of the rectifier units 21 to 25 when there is no conversion loss) is indicated by a solid line. As a comparative example, purchased power when there is no control of the control unit 30 is indicated by an alternate long and short dash line.

  At time t0 to t1, the DC power supply system 100 performs a normal operation. At this time, since the power consumption of the communication apparatus 3 is the power consumption when no power failure occurs (power consumption Pload1 at normal time), the purchased power is power consumption Pload1 at normal time.

  A power failure occurs at time t1 to t2. At this time, purchased power is zero. Moreover, since it is at the time of a power failure, the power consumption Pload of the communication apparatus 3 is covered by the discharge power Pd from the storage battery 4.

  After time t2, the power failure recovers, and power recovery occurs. At this time, the power consumption Pload of the communication device 3 and the charging power Pc of the storage battery 4 become large. If control by control unit 30 is not performed, as indicated by the one-dot and dash line, a peak of purchased power occurs, and at time t2 to t3, the peak exceeds the contract power. On the other hand, in the present embodiment, the number of operating the rectifier units 21 to 25 is limited by the control of the control unit 30. Thus, as indicated by the solid line, the purchased power is limited not to exceed the contracted power.

  At time t4, when the storage battery 4 finishes charging and enters a normal state (floating charge state), the measurement unit 32 detects a decrease in the current Irc, and the adjustment unit 34 limits the number of operating rectifier units 21 to 25. Cancel (return the number of operation to the normal number (5)).

  According to the rectifier 10 described above, the number of operation of the rectifier units 21 to 25 which convert purchased power Pu from the commercial power source 1 into output power Prc and output it to the communication device 3 and the storage battery 4 is at power recovery. It is limited (steps S2 and S3, times t2 to t4). Thus, the magnitude of the purchased power Pu received from the commercial power supply 1 as a whole by the rectifier units 21 to 25 is limited, so that the peak of the purchased power Pu of the DC power system 100 at the time of power recovery can be suppressed.

  The control unit 30 limits the number of operating the rectifier units 21 to 25 so that the output power Prc output from the rectifier units 21 to 25 to the communication device 3 and the storage battery 4 does not exceed a predetermined power at power recovery. (Steps S2 and S3). As a result, the purchased power Pu at the time of power recovery can be prevented from exceeding the predetermined power (for example, the contract power) (time t2 to t3).

  When the current Irc flowing from the rectifier units 21 to 25 toward the communication device 3 and the storage battery 4 falls below the predetermined current, the control unit 30 releases the restriction on the number of operating the rectifier units 21 to 25 (steps S4 to S6). Thereby, restriction | limiting of the number of operation of the rectifier units 21-25 can be cancelled | released with a suitable timing (time t4).

  After power recovery, control unit 30 limits the number of operating rectifier units 21 to 25 so that the SOC of storage battery 4 reaches a predetermined charging rate (for example, 100%) within a predetermined period (for example, within 20 hours) Steps S2 and S3). As a result, after the power recovery, the SOC of the storage battery can be recovered within a predetermined period (time t2 to t4).

  Control of the control unit 30 is realized, for example, by the cooperation of the storage unit 31, the measurement unit 32, the calculation unit 33, and the adjustment unit 34.

  Here, as a control method of the charging current of the storage battery 4, a method of charging the storage battery with a constant charging current by the period when the fully charged state is required using the charge and discharge control device can be considered. However, the communication device 3 such as a wireless base station basically does not have a charge / discharge control device for the storage battery 4. For this reason, the method using control by the rectifier 10 as described above is useful. According to this method, it is possible only by adding control software of the rectifying device 10, and there is an advantage that new hardware is not required. In addition, depending on the type of the storage battery 4, it is not necessary to develop each, so the cost can be reduced.

  Moreover, the rectifier 10 which concerns on this embodiment can make variable the number of the rectifier units to drive | work. For example, in the case of a DC power supply system 100 for a communication device 3 such as a wireless communication base station, power is usually supplied to the communication device 3 by a plurality of rectifier units including a redundant configuration. Also from this point of view, control of the rectifier 10 can be realized without the need for new hardware.

  As described above, according to the rectifying device 10, in the communication device 3 such as a wireless base station, it is possible to suppress the power at the time of power recovery which requires the most power instantaneously, and the storage battery 4 as a backup power supply It is possible to reduce the electricity charges while securing the charge of the Further, even if there is no charge / discharge control device for the storage battery 4, control of the conversion unit 20 in the rectifier 10 (for example, control of the number of operating the rectifier units 21 to 25) is necessary to add new hardware. As a result, it is possible to reduce the electricity charge of the existing communication device 3.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment. For example, the following modifications may be made to the embodiments of the present invention.

  For example, although the said embodiment was related to control of the conversion part 20 in the rectifier 10, when the charge / discharge control apparatus of the storage battery 4 is provided in DC power supply system 100 for communication apparatuses 3 like a wireless communication base station In this case, the amount of charge determined by the charge / discharge control device at the time of power recovery may be set to a current value that becomes the aforementioned threshold (such as step S4).

  When the output voltage of the conversion unit 20 (rectifier units 21 to 25) is variable, the peak current may be suppressed by controlling the voltage.

  Moreover, although the said embodiment provided the measurement part 32 and the adjustment part 34 for output current detection in the inside of the rectifier 10, they may be provided in the exterior of the rectifier 10. As shown in FIG.

  In addition, since the above-described embodiment instantaneously requires the most power at the time of power recovery, peak power is suppressed by controlling the charging current of the storage battery 4 to reduce the electricity charge. The load of the case is not limited to the radio base station (such as the communication device 3).

  Although the above embodiment assumes that peak power is generated at the time of power recovery, the use of an air conditioner in which power consumption fluctuates, the case where on / off control is performed on the communication device 3 itself, etc. When the communication device 3 is a device configuration that generates peak power during normal operation, it is necessary in cooperation with an external device such as an AC power measuring instrument or the on / off control unit of the communication device 3 along with discharge of the storage battery 4 The peak power may be suppressed by performing on / off control (operation / stop control) of the rectifier units 21 to 25 so as to supply power for a minute.

  DESCRIPTION OF SYMBOLS 1 ... Commercial power supply (AC electric power network), 3 ... Communication apparatus (load), 4 ... Storage battery, 10 ... Rectification apparatus, 21-25 ... Rectifier unit, 30 ... Control part, 31 ... Storage part, 32 ... Measurement part, 33 ... Calculation unit, 34 ... adjustment unit.

Claims (4)

A rectifier used in a DC power supply system for supplying power from a storage battery to a load which is communication equipment when a power failure occurs in an AC power network,
A plurality of rectifier units for receiving AC power from the AC power network and converting it into DC power when there is no power failure in the AC power network, and outputting the converted DC power toward the load and the storage battery;
Control means for limiting the number of operating the plurality of rectifier units at the time of power recovery of the AC power network;
Equipped with
The control means limits the number of operating rectifier units so that the charging rate of the storage battery reaches a predetermined charging rate within a predetermined period after the recovery of the AC power network.
Rectification device.   The control unit limits the number of operating the plurality of rectifier units such that the power output from the plurality of rectifier units toward the load and the storage battery does not exceed a predetermined power at the time of power recovery. The rectifier according to 1.   The said control means cancels | releases the restriction | limiting of the operation number of these rectifier units, when the electric current which flows to the said load and the said storage battery from these rectifier units is less than predetermined current. Rectification device. The control means
A storage unit for storing power consumption of the load when no power failure occurs;
A measurement unit that measures discharge power of the storage battery at the time of a power failure;
A calculation unit that calculates a charging rate of the storage battery at the end of the power failure based on the measurement result by the measurement unit;
The storage battery within the predetermined period based on the power consumption of the load stored in the storage unit, the charging rate of the storage battery at the end of the power outage calculated by the calculating unit, the predetermined charging rate, and the predetermined period An adjusting unit that adjusts the number of operating the rectifier units such that the charging rate of the battery reaches the predetermined charging rate;
including,
The rectification device according to any one of claims 1 to 3 .

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