JP2010154613A - Dc power supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a DC power supply device reducing a power loss compared with a conventional device by controlling the number of rectifier units and operating the rectifier units in a high power conversion efficiency when the DC power supply device mounting a plurality of rectifier units for converting AC power into DC power is operated at an inefficient load rate. <P>SOLUTION: This DC power supply device has: a plurality of rectifier units connected in parallel to output terminals for outputting DC power; a wiring breaker arranged between the rectifier units and the AC power supply per rectifier unit; a current sensor for measuring a current value of the DC output power and outputting a measured current value; and an operation unit number control section for obtaining the number of rectifier units at which the loss for converting AC into DC becomes the smallest for each of rectifier units with a current value, and controlling so that the DC power can be outputted from the number of operating rectifier units. The operating number control section makes opening/closing control of the wiring breaker connected to the rectifier units so as to correspond to the number of operating units. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a DC power supply device used in a communication building, a data center, or the like.

A DC power supply device is usually configured by connecting a plurality of rectifier units in parallel to a load (see, for example, Patent Document 1 and Patent Document 2).
Since each rectifier unit is connected in parallel with the load, each of the load currents connected to the load in parallel is uniformly supplied. For example, when 100 A is supplied to the load, if five rectifier units are provided in parallel, each rectifier unit supplies power by 20 A.
JP 2006-311736 A JP 2007-318949 A

  However, when actually operating the DC power supply device, it is necessary to operate all rectifier units in the DC power supply device, assuming that the load current is always maximized. It may be necessary to operate at a rate (output current / rated current). Generally, when the rectifier unit is operated at a low load factor, the power conversion efficiency is low, and extra power loss may occur in the power conversion in the rectifier unit.

  The present invention has been made in view of such circumstances, and in the case where a DC power supply device equipped with a plurality of rectifier units that convert AC power into DC power is operating at an inefficient load factor, the load current is An object of the present invention is to provide a direct current power supply device that can operate a rectifier unit with high power conversion efficiency by controlling the number of rectifier units that output power, and can reduce power loss as compared with the prior art.

  A DC power supply device according to the present invention includes a plurality of rectifier units connected in parallel to an output terminal that outputs DC power, and a wiring provided between the rectifier unit and an AC power source for each of the rectifier units. A circuit breaker, a current sensor that measures the current value of the DC output power, and outputs the current value of the DC output power, and the loss when the rectifier unit is converted from AC to DC by the current value is minimized. An operating number control unit that controls the output number of the rectifier units to be controlled so that DC power is output from the rectifier units of the operating number, and the operating number control unit corresponds to the operating number Further, the switching control of the circuit breaker connected to the rectifier unit is performed.

  The DC power supply device according to the present invention is characterized in that the operating number control unit inputs the current value at a preset period and calculates the operating number of the rectifier units.

  The DC power supply device of the present invention is further provided with a voltage sensor that is provided at the output terminal, measures a voltage value of the output terminal, and outputs a voltage value, and the operating number control unit has a preset threshold voltage And the voltage value, and when the voltage value deviates from the threshold voltage, all the rectifier units are put into operation.

  The DC power supply device of the present invention is further provided with a voltage sensor that is provided at the output terminal, measures a voltage value of the output terminal, and outputs a voltage value, and the operating number control unit has a preset threshold voltage When the voltage value deviates from the threshold voltage, one or a predetermined number of rectifier units are sequentially activated until the voltage value exceeds the threshold voltage. It is characterized by that.

  The DC power supply device of the present invention includes an operating number table in which the current value of the DC output power and the operating number of the rectifier unit with the smallest loss when converted into converted DC at the current value are set in correspondence with each other. The operation number of the rectifier unit corresponding to the current value from the current sensor is read from the operation number table, the calculation unit for obtaining the operation number of the rectifier unit, and the operation number obtained by the calculation unit And a control unit for controlling the circuit breaker.

  The DC power supply device according to the present invention includes a loss table in which the operating number control unit associates a current value output per rectifier unit with a power loss in the case of the current value, and a current from the current sensor. The current value is divided by the number of currently operating rectifier units to obtain a first current value of the output current per unit, and the power loss corresponding to the first current value is represented in the loss table. The current value from the current sensor is divided by the number obtained by increasing or decreasing the current operating number by one to obtain the second and third current values, respectively, and the second and third current values are obtained. The power loss corresponding to each is read from the loss table, and when the power loss at the first current value is smaller than the power loss at the second and third current values, the current operating number is calculated. If the power loss in the reduced number is small, subtract to the number with the smallest power loss, while if the power loss in the increased number is small, increase to the number with the smallest power loss. A calculating unit that outputs the number of small power losses obtained as the number of operating rectifier units, and a control unit that controls the circuit breaker in correspondence with the operating number obtained by the calculating unit. Features.

  As described above, according to the present invention, even when the load power fluctuates and the load current flowing through the load (the output current output from the DC power supply device) decreases, the loss at the time of conversion is the most in the reduced output current. The number of operating rectifier units with a small current is obtained, and the circuit breaker inserted between the AC power source and the rectifier unit is controlled so as to be the number of operating units. The rectifier unit can be operated with a small number of operating units, and excessive energy consumption can be suppressed as compared with the conventional case.

  In addition, according to the present invention, when the voltage drops across the measurement period, the rectifier unit in which the operation number control unit is not operating is operated unconditionally, so the load power increases and the load current increases rapidly. Even in this case, the output voltage can be maintained at a voltage level required for the load.

<First Embodiment>
Hereinafter, the DC power supply device according to the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration example of a DC power supply device according to the first embodiment of the present invention.
As shown in this figure, the DC power supply device 1 according to the present embodiment inputs AC power from a commercial power source (AC power source) 100 and supplies DC power to the load facility 200 at a constant voltage. Yes.
The DC power supply device 1 includes a circuit breaker (circuit breaker for wiring) 2-1, circuit breaker 2-2, circuit breaker 2-3,..., Circuit breaker 2-n, rectifier unit 3-1, rectifier unit 3-2. , Rectifier unit 3-3,..., Rectifier unit 3-n, current sensor 4, current measuring unit 5, voltage sensor 6, voltage measuring unit 7, and operating number control unit 8.
Each of the rectifier unit 3-1 to the rectifier unit 3-n is provided in parallel to the load facility 200, each output is connected at the connection point A, and each input is the circuit breaker 2-1 to the circuit breaker 2. -N is connected to the commercial power source 100 through each of the -n. That is, each rectifier unit has its input connected to the commercial power source 100 via a circuit breaker.

The current sensor 4 is provided, for example, between the connection point A and the output terminal 9 (any position may be used as long as the load current supplied from the DC power supply device 1 to the load facility 200 can be measured). The current value of the load power output from the output terminal 9 is measured, and the measured current value is output to the current measuring unit 5.
The current measurement unit 5 reads the input current value at a predetermined measurement cycle set in advance, and outputs it as current value data to the operating number control unit 8.
The voltage sensor 6 measures, for example, the voltage value of the output terminal of the current sensor 4 (in order to measure the voltage value of the output voltage output from the output terminal 9) The measured voltage value is output to the voltage measuring unit 7.
The voltage measuring unit 7 reads the input voltage value at a predetermined measurement cycle, and outputs it to the operating number control unit 8 as voltage value data.

  The number-of-operations control unit 8 uses the current value data input from the current measurement unit 5 to operate the rectifier that minimizes the loss when converting from AC to DC in each of the rectifier units 3-1 to 3-n. The number of units is obtained, and control is performed so that a DC voltage is output from the rectifier of the obtained number of operating units.

Next, the operation number control unit 8 in FIG. 1 will be described with reference to FIG. FIG. 2 is a conceptual diagram showing the configuration of the operating number control unit 8 in FIG.
The operating number control unit 8 includes an input unit 11, a calculation unit 12, a timer 13, a storage unit 14, and a control unit 15.
The control unit 15 provides, via the input unit 11, an operating number table in which the current value of the load current and the operating number at which the efficiency of conversion from alternating current to direct current becomes the minimum at this current value are indicated. The data is read and stored in the storage unit 14 before the operation of the DC power supply device.
In addition, the control unit 15 stores the load power current value input from the current measurement unit 5 in the storage unit 14 corresponding to the read time, and the load power current value corresponding to the latest time in the control cycle. Is read from the storage unit 14 and output to the calculation unit 12.

The timer 13 counts the time, and outputs a cycle notification signal to the control unit 15 when the operation number control unit 8 has reached the control cycle for controlling the number of operating rectifier units.
The calculation unit 12 reads the number of operating units corresponding to the current value of the load power input from the control unit 15 in the control cycle from the operating unit table of the storage unit 14.

  As described above, as shown in FIG. 3, the operation number table shows the correspondence between the current value of the load current and the number of stopped units that have the smallest power loss at the current value of the load power. It is a table to show. In the operating number table of FIG. 3, n = 8 rectifier units of the DC power supply device are shown. In this figure, although the number of stops is shown, it may be formed so as to show the number of operating units.

A method for creating this table will be described below.
Each of the rectifier units 3-1 to 3-n is voltage control (CV) targeting the same voltage, and a plurality of them are connected in parallel and all outputs are connected in common. The current value obtained by dividing the current value of the load power to be divided by the number of operating units is evenly distributed and output.
The load current IL output from the DC power supply is divided by the number of the minimum number of operating units or more that can be supplied in total, and the output current of each rectifier unit for each different number of operating units is calculated.

For example, in the case of the maximum load current IL that can be supplied by one unit, the output current output from each rectifier unit is obtained as I _{un ′} by the following equation.
Iun _' = IL / n', Iun _' = IL / (n'-1), ..., Iun _' = IL
Here, the output current _{Iun ′} indicates the output current of each rectifier unit when the rectifier unit n _′ is operated.

Then, the calculated power loss P corresponding to each output current is read from the “load current-loss power” characteristic of the rectifier unit, multiplied by the number of rectifier units when divided, and the total power loss for each unit is calculated. Is calculated. That is, when the output current is I _{un ′} , the obtained power loss P _un ′ is multiplied by n ′ to calculate the total power loss in the DC power supply device. Then, the smallest number of total power loss is set as the number of operating load currents IL, and this number of operating units is subtracted from the total number of rectifier units to obtain the number of stopped units.

  From the load current IL that can be output by one rectifier unit to the maximum load current IL that can be output by the number of all rectifier units installed in the DC power supply unit, it is calculated for each predetermined load current range, An optimum operating number that minimizes the total power loss at the load current IL is obtained, the number of rectifier units that correspond to the load current IL, and stop at the load current IL is shown, and an operating number table is created.

Next, an operation example of the DC power supply device according to the first embodiment will be described with reference to FIGS. 1 to 3.
The storage unit 14 will be described in a state where the operating number table shown in FIG. 3 has already been read.
a. The current measuring unit 5 reads the current value of the load power output from the current sensor 4 for each preset period and outputs it to the operating number control unit 8.
The control unit 15 writes the current value of the input load power in the storage unit 14 corresponding to the input time.
b. When a signal indicating a control cycle is input from the timer 13, the control unit 15 corresponds to the time closest to the current time and the current value of the load power stored in the storage unit 14, that is, the latest current value. Read and output to the calculation unit 12.
c. The computing unit 12 reads out the number of stops corresponding to the input current value of the load power from the operating number table of the storage unit 14 and outputs it to the control unit 15.
d. Since the number of the rectifier units in which the circuit breaker is open (non-conducting state), that is, the number of stops in the DC power supply device at the present time, that is, the number of stops is the same as the number of stops input from the arithmetic unit 12, Close (conducting state) and open (non-conducting state) control of each circuit breaker is performed.
B. ~ D. This process is performed for each cycle and each control cycle. a. Is performed in a preset cycle shorter than the control cycle.

In the above d, for example, when there are eight rectifier units 3-1 to 3-8 in the DC power supply and the number of units currently stopped is three (3-1 to 3-3), the number of stopped units Are input from the calculation unit 12 as four units, the control unit 15 opens the circuit breaker 2-4 of the rectifier unit 3-4 in numerical order, stops the rectifier unit 3-4, and rectifier units 3-1 to 3-3. 4 units up to -4 are stopped. On the other hand, when the number of stops is input from the arithmetic unit 12 as two units, the control unit 15 closes the circuit breaker 2-3 of the rectifier unit 3-3 in order of numbers, operates the rectifier unit 3-3, and rectifier unit 3 Control is performed to stop two units -1 and 3-2.
As described above, according to the present embodiment, the load power supplied to the load facility 200 can be operated in the state where the total loss of the rectifier unit provided in the DC power supply device is the smallest, and wasteful energy is reduced. Consumption can be suppressed.
In the present embodiment, as shown in the table of FIG. 3, when the load current value is 0, all circuit breakers corresponding to 8 rectifier units are opened, and all rectifier units are opened. It is configured to be in a stopped state. However, even when the current value of the load current is 0, the circuit breaker corresponding to the seven rectifier units is opened so that it is included when the total loss of the rectifier units is the smallest when the number of operating units is one. The circuit breaker corresponding to one rectifier unit may be closed, and at least one rectifier unit may be in an operating state even when the current value of the load current is zero.

In addition, when the load power suddenly decreases and the load current increases at a time other than the time when the operation number control process is performed in the control cycle, the supply power is insufficient in the current operating number, and the DC power supply device The voltage value of the output voltage at the output terminal decreases from the constant voltage value Vn. In FIG. 4, the horizontal axis indicates time, and the vertical axis indicates the voltage value of the output voltage at the output terminal 9.
When the control unit 15 constantly detects the voltage value data input from the voltage measurement unit 7 and detects that the voltage value data has decreased from the constant voltage value Vn and has become less than the preset voltage value VL. In order to operate a preset number of rectifier units (one unit or a plurality of units including all units), the circuit breakers connected to the corresponding rectifier units are closed. In the following description, the number of rectifier units provided in the DC power supply apparatus is eight, 2-1 to 2-8.

For example, when operating rectifier units one by one, when the rectifier units 3-1 to 3-3 are operating, the control unit 15 opens when detecting that the output voltage is less than the voltage value VL. The circuit breakers are closed in numerical order, that is, the circuit breakers 2-4 are closed.
Thereby, when the rectifier unit 3-4 operates, the load power is supplied to the load facility 200 by the rectifier units 3-1 to 3-4.
Moreover, when the output voltage is less than the voltage value VL in the result of supplying the load power to the load facility 200 by the four rectifier units by the above-described processing, the control unit 15 determines that the output voltage is less than the voltage value VL. When it is detected that the circuit breaker is disconnected, the circuit breakers that have been disconnected are closed in numerical order, that is, the circuit breakers 2-5 are closed. In this way, the control unit 15 sequentially operates the rectifier units until the output voltage becomes equal to or higher than the voltage value VL.

Further, when the rectifier units are operated in units of a plurality of units, for example, two units at a time, when the rectifier units 3-1 to 3-3 are operating, the control unit 15 has an output voltage of less than the voltage value VL. When this is detected, the open circuit breakers are closed in numerical order, that is, the circuit breakers 2-4 and 2-5 are closed.
Thereby, when the rectifier units 3-4 and 3-5 are operated, load power is supplied to the load facility 200 by the rectifier units 3-1 to 3-5.
Moreover, when the output voltage is less than the voltage value VL in the result of supplying the load power to the load facility 200 by the five rectifier units by the above-described processing, the control unit 15 determines that the output voltage is less than the voltage value VL. When it is detected that the circuit breaker has become open, the circuit breakers that are open are closed in numerical order, that is, the circuit breakers 2-6 and 2-7 are closed. In this way, the control unit 15 sequentially operates the rectifier units until the output voltage becomes equal to or higher than the voltage value VL.

When all the rectifier units are operated, when the rectifier units 3-1 to 3-3 are operating, the control unit 15 opens when detecting that the output voltage is less than the voltage value VL. Close all the circuit breakers that are, that is, close the circuit breakers 3-2 to 2-8.
Thereby, when the rectifier units 3-4 to 3-8 are operated, load power is supplied to the load facility 200 by the rectifier units 3-1 to 3-8.
As described above, when the load power increases at the time when the number of operating units is controlled in the control cycle (that is, when the control of b. To d. Is performed) and the output voltage becomes less than the voltage value VL, the control is performed. The unit 15 sets the output voltage so that the output voltage becomes equal to or higher than the voltage value VL. ~ D. Regardless of the operation number control processing in, control is performed to close the circuit breaker according to the voltage value of the output voltage.
However, when the control period is reached, b. ~ D. , I.e., the number-of-operations control process is newly performed, b. ~ D. This process is repeated.
By detecting the change in the voltage value of the output voltage described above and adding a process for controlling the number of operating rectifier units, the load power changes abruptly at times other than when the number of operating units is controlled in the control cycle. However, rated power can be supplied to the load facility 200 without significantly reducing the output voltage.

<Second Embodiment>
Hereinafter, the DC power supply device according to the second embodiment of the present invention will be described with reference to the drawings. The configuration of the second embodiment is the same as that of the first embodiment shown in FIG. 1 except that the number of operating units calculated by the calculation unit 12 and the calculation unit 12 stored in the storage unit 14 are different. Only the table used for calculating the number of operating units is different.
Hereinafter, the points of the second embodiment different from the first embodiment will be described.
As shown in FIG. 5, the table stored in the storage unit 14 includes the output current I _{LS of} one rectifier unit (output current of 0% to 100% with respect to the rated current) I _LS and the output current I _LS . It is a loss table with which power loss P _{loss at the} time of output is matched.
The loss table is also input from the outside via the input unit 11 and written and stored in the storage unit 14 in advance before the DC power supply device operates.
The control unit 15 detects the number of operating rectifier units from the number of circuit breakers that are closed, and outputs the detected number of operating rectifier units to the arithmetic unit 12 as the current number of operating rectifier units n _{t. Is} output to the calculation unit 12 as the total current _ILt of the current value data.

Hereinafter, an operation example of the operation number calculation process in the calculation unit 12 will be described with reference to the flowchart of FIG. 6. In the following processing, the total number of rectifier units provided in the DC power supply device is n _all .
When the total current _ILt is input, the calculation unit 12 inputs the current operating number _nt and the total current _ILt from the control unit 15 (step S1), and the input total current _ILt is input to the operating unit. Divide by n _t to calculate a unit load current I _Ltn per rectifier unit (step S2).
Then, the arithmetic unit 12, the power loss _{P Lossn} corresponding to the calculated unit load current _{I Ltn,} read by searching the loss table (step S3).

Next, the calculation unit 12 adds 1 to the current operating number n _t , divides the total current I _Lt by n (= n _t +1), and performs a predetermined digit number processing (for example, rounding off). To calculate a unit load current I _{Ltn + 1} per rectifier unit (step S4).
Then, the calculation unit 12 searches the loss table for the power loss P _{lossn + 1} corresponding to the calculated unit load current I _{Ltn + 1} and reads it (step S5).

Next, the arithmetic unit 12 subtracts 1 from the current operating number n _t , divides the total current I _Lt by n (= n _t −1), and processes a predetermined number of digits (for example, rounding off). To calculate a unit load current _ILtn-1 per rectifier unit (step S6).
The operating section 12 is the power loss _{P lossn-1} corresponding to the unit load current I _Ltn-1 calculated ,,, read by searching the loss table (step S7).

After calculating the unit load current I _{Ltn + 1} and the unit load current I _Ltn−1 , the calculation unit 12 determines whether or not the power loss P _{lossn + 1} is larger than the power loss P _lossn (step S8), and the power loss P _{lossn + 1} is If it is greater than the power loss P _lossn , the process proceeds to step S10, and if the power loss P _{lossn + 1} is smaller than the power loss P _lossn , the process proceeds to step S9.
When the power loss P _{lossn + 1} is larger than the power loss P _lossn , the calculation unit 12 determines whether n is n _all (step S10), and when n is n _all , the operation exceeds n _all. Since the number cannot be increased, the process proceeds to step S12.

On the other hand, when the power loss P _{lossn + 1} is smaller than the power loss P _lossn , the arithmetic unit 12 determines whether or not the power loss P _lossn−1 is larger than the power loss P _lossn (step S9), and the power loss P _{lossn−. If 1} is greater than power loss P _lossn , the process proceeds to step S12. If power loss P _{lossn + 1} is less than power loss P _lossn , the process proceeds to step S11.
When the power loss _Plossn-1 is larger than the power loss P _lossn , the calculation unit 12 determines whether n is 1 (step S11). When n is 1, the number of operating units is determined from n = 1. Since it cannot be decreased, the process proceeds to step S6. When n is not 1, the process proceeds to step S6.

Through the processing described above, the calculation unit 12 outputs the number of operating units corresponding to the smallest power loss P to the control unit 15 (step S12).
For example, when the power loss P _lossn is the smallest, the calculation unit 12 _outputs the current operation number nt as the operation number of the calculation result to the control unit 15, and when the power loss P _{lossn + 1} is the smallest, the current operation number nt + m When the power loss P _lossn-1 is the smallest, the current operation number nt-m (m is step S6) is output to the control unit 15 as the operation number as the operation result. Is output to the control unit 15 as the number of operating results.
Thereby, the control part 15 performs the switching control of a circuit breaker so that it may become the operation number input from the calculating part 12, similarly to 1st Embodiment.

Further, as shown in FIG. 7, the order of the processes of steps S4 and S5 and steps S6 and S7 in the flowchart of FIG. 6 is interchanged, and similarly, the order of steps S9 and S8 is interchanged, and the power loss P _lossn 6 is _first determined whether the power loss is less than the power loss P _lossn−1 , and then it is determined whether the power loss is smaller than the power loss. The number of operating rectifier units with the smallest loss can be obtained.
Also, as shown in FIG. 8, step S8 is performed between step S5 and step S6 in the flowchart of FIG. 6, and step S9 is performed between step S7 and step S12 to increase the number of operating units. If the power loss decreases, only the process of increasing the number of operating units sequentially is performed. On the other hand, if the power loss decreases when the number of operating units decreases, only the process of decreasing the number of operating units is performed. Even if the processing is performed in the order shown in the flowchart of FIG. 8, the number of operating rectifier units with the smallest power loss can be obtained in the same manner as the processing of the flowchart of FIG.
Further, as shown in FIG. 9, the order of the processes of steps S4 and S5 and steps S6 and S7 in the flowchart of FIG. 6 is changed, and step S9 is performed between steps S7 and S4. Step S8 is performed between step S5 and step S12, and when power loss is reduced when the number of operating units is reduced, only processing for sequentially reducing the number of operating units is performed. On the other hand, if the power loss decreases when the number of operating units is increased, only the process of increasing the number of operating units is performed. Even if the processing is performed in the order shown in the flowchart of FIG. 9, the number of operating rectifier units with the smallest power loss can be obtained as in the processing of the flowchart of FIG. 6.

  In the second embodiment, the number of rectifier units that operate in response to load power is controlled so that the power loss of each rectifier unit is minimized. it can.

  1 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into the computer system and executed, thereby executing the number of operating units. The calculation process and the operation control of the rectifier unit may be performed. The “computer system” here includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

It is a block diagram which shows the structural example of the DC power supply device by the 1st Embodiment of this invention. It is a block diagram which shows the structural example of the operation number control part 8 of FIG. In 1st Embodiment, the calculating part 12 is a conceptual diagram which shows the structure of the operation number table used for the calculation process of the operation number of a rectifier unit. It is a wave form diagram explaining the process of the control part 15 when the output voltage of a DC power supply device increases rapidly. In 2nd Embodiment, it is a conceptual diagram which shows the structure of the loss table which the calculating part 12 memorize | stored in the memory | storage part 14 uses for calculation of the number of operation. It is a flowchart which shows the operation example of the calculation process of the calculating part 12 in 2nd Embodiment of the operation number of a rectifier unit. It is another flowchart in which the calculating part 12 in 2nd Embodiment shows the operation example of the calculation process of the operation number of a rectifier unit. It is another flowchart in which the calculating part 12 in 2nd Embodiment shows the operation example of the calculation process of the operation number of a rectifier unit. It is another flowchart in which the calculating part 12 in 2nd Embodiment shows the operation example of the calculation process of the operation number of a rectifier unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... DC power supply device 2-1, 2-2, 2-3, 2-n ... Circuit breaker 3-1, 3-2, 3-3, 3-n ... Rectifier unit 4 ... Current sensor 5 ... Current measurement part DESCRIPTION OF SYMBOLS 6 ... Voltage sensor 7 ... Voltage measurement part 8 ... Active number control part 9 ... Output terminal 11 ... Input part 12 ... Calculation part 13 ... Timer 14 ... Memory | storage part 15 ... Control part 100 ... Commercial system power source 200 ... Load equipment

Claims (6)

A plurality of rectifier units connected in parallel to an output terminal that outputs DC power;
For each rectifier unit, a circuit breaker provided between the rectifier unit and the AC power source,
A current sensor that measures the current value of the DC output power and outputs the current value of the DC output power; and
Based on the current value, the number of operating units of the rectifier unit that minimizes the loss when converting the AC from each AC of the rectifier units is determined, and the number of operating units that is controlled so that DC power is output from the rectifier units of the operating units A control unit, and
The DC power supply device characterized in that the operating number control unit performs opening / closing control of a circuit breaker connected to the rectifier unit so as to correspond to the operating number.   2. The DC power supply device according to claim 1, wherein the operating number control unit inputs the current value at a preset period and calculates the operating number of the rectifier units. A voltage sensor that is provided at the output terminal, measures a voltage value of the output terminal, and outputs a voltage value;
The operating number control unit compares a preset threshold voltage with the voltage value, and when the voltage value deviates from the threshold voltage, all the rectifier units are set in an operating state. Item 5. The DC power supply device according to Item 1 or Item 2. A voltage sensor that is provided at the output terminal, measures a voltage value of the output terminal, and outputs a voltage value;
The operating number control unit compares a preset threshold voltage with the voltage value, and when the voltage value deviates from the threshold voltage, one or a preset number of rectifier units are replaced with the voltage value. The DC power supply device according to claim 1, wherein the DC power supply device is sequentially operated until the voltage exceeds the threshold voltage. The operating number control unit is
An operating number table in which the current value of the DC output power and the operating number of the rectifier unit with the smallest loss when converting to DC at the current value are set correspondingly,
The number of operating units of the rectifier unit corresponding to the current value from the current sensor is read from the operating unit table, and a calculating unit for obtaining the number of operating rectifier units;
The DC power supply device according to any one of claims 1 to 4, further comprising: a control unit that controls the circuit breaker in correspondence with the number of operating units obtained by the calculation unit. The operating number control unit is
A loss table that associates the current value output per rectifier unit with the power loss in the case of the current value;
The current value from the current sensor is divided by the number of currently operating rectifier units to obtain a first current value of the output current per unit, and the power corresponding to the first current value The loss is read from the loss table, and the current value from the current sensor is divided by the number of current operating units that are increased or decreased by one to obtain the second and third current values, respectively. When the power loss corresponding to each of the third current values is read from the loss table and the power loss at the first current value is smaller than the power loss at the second and third current values, the current operating number is calculated as the result. When the power loss in the reduced number of units is small, the number of units with the smallest power loss is subtracted. On the other hand, if the power loss in the increased number is small, the smallest A calculation unit increases to the number to be had power loss, and outputs the number of smallest obtain a power loss as number of operating the rectifier unit,
The DC power supply device according to any one of claims 1 to 4, further comprising: a control unit that controls the circuit breaker in correspondence with the number of operating units obtained by the calculation unit.

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