JP2010154614A - 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 rate. <P>SOLUTION: This DC power supply device has: a plurality of rectifier units connected in parallel between output terminals for receiving inputted AC power and outputting DC power; a current sensor for measuring a current value of the DC power and outputting a current value of the DC power; 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 with a current value, and controlling so that the DC power can be outputted from the number of operating rectifier units. The DC power supply device compares a detected voltage value obtained by dividing an output voltage by the rectifier unit, with a reference voltage to control the output voltage, and outputs the output voltage via a diode. The operation number control section controls the voltage division ratio to control the operation of the rectifier 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 always necessary to operate all the rectifier units in the DC power supply device assuming that the load current becomes maximum. There are cases where it is necessary to operate at a low load factor (output current / rated current). However, 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.

  The DC power supply device of the present invention measures the current value of the DC power, a plurality of rectifier units connected in parallel between an AC power input and an output terminal that outputs DC power, and the DC power A current sensor that outputs a current value, and the current value determines the number of operating rectifier units that minimizes the loss of conversion from AC to DC in each rectifier unit. A control unit for controlling the number of operating units to be output, and the rectifier unit compares a detected voltage value obtained by dividing the output voltage of the output unit by a voltage dividing circuit with a preset reference voltage, and outputs an output voltage. The output voltage is output through the diode, and the operation number control unit controls the voltage dividing ratio of the voltage dividing circuit, thereby controlling the operation of the rectification unit corresponding to the operation number. And wherein the Ukoto.

  In the DC power supply device of the present invention, the operating number control unit controls the voltage dividing ratio of the voltage dividing circuit, increases the detected voltage value compared to before voltage division, and outputs the voltage value of the output voltage during operation. The supply of DC power from the rectifier unit is stopped by lowering the voltage compared to the voltage.

  In the DC power supply device of the present invention, the voltage dividing circuit is configured by connecting resistors in series, and a switch is connected in parallel with any of the resistors, and the operating number control unit is the switch The voltage dividing ratio of the voltage dividing circuit is controlled by controlling opening / closing of the voltage dividing circuit.

  The DC power supply device according to the present invention is characterized in that the detected voltage value is set so that the voltage value of the output voltage is included in an input voltage range of a load in which the load operates.

  In the DC power supply device of the present invention, the operating number control unit includes an operating number table in which the current value of the DC power and the operating number of the rectifier unit having the smallest power loss at the current value are set correspondingly. 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 controller for controlling the switch.

  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 calculation unit that outputs the number of small power losses obtained as the number of operating rectifier units, and a control unit that controls the switch in correspondence with the number of operating units determined by the calculation unit. Features.

  As described above, according to the present invention, even when the load resistance changes and the load current flowing through the load (the output current output from the DC power supply) decreases, the rectifier unit having the smallest power loss in the reduced output current. By reducing the output voltage of the rectifier unit that is not operated so that it becomes this operating number, the rectifier unit can be easily operated with a number with good conversion efficiency. Energy consumption can be suppressed.

  Further, according to the present invention, the diode has a voltage value obtained by subtracting the forward voltage drop value of the diode from the output voltage value of the rectifier unit that does not operate the output voltage of the DC power supply device even if the load current suddenly increases. It can turn on and the load can maintain the required voltage level.

<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 receives AC power from a commercial power source (AC power supply) 100, and DC power is supplied to the PFC unit 2-1b via the FIL unit 2-1a. The DC power stabilized by the DC-DC unit 2-1c controlled by the negative feedback circuit and supplied to the load facility 200 is supplied to the load facility 200.
The DC power supply device 1 includes a rectifier unit 2-1, a rectifier unit 2-2, a rectifier unit 2-3,..., A rectifier unit 2-n, a current sensor 3, a current measuring unit 4, and an operating number control unit 5. Have.

Each of the rectifier unit 2-1 to the rectifier unit 2-n is provided in parallel between the commercial power source 100 and the load facility 200, and each output is connected at a connection point A. The input is connected to the commercial power source 100.
The current sensor 3 is provided between the connection point A and the output terminal 9, measures the current value of the load current output from the output terminal 9, and outputs the measured current value to the current measuring unit 4.

The current measuring unit 4 reads the input current value at a predetermined measurement cycle, and outputs it as current value data to the operating number control unit 5.
The number-of-operating-unit control unit 5 uses the current value data input from the current measuring unit 4 to operate the number of rectifiers that minimizes power loss when performing direct-current to direct-current conversion of each of the rectifier units 2-1 to 2-n. Then, control is performed so that DC power is output from the rectifiers of the determined number of operating units.

Each of the rectifier unit 2-1 to rectifier unit 2-n has the same configuration. Hereinafter, the configuration of the rectifier unit will be described with reference to the rectifier unit 2-1, but the other rectifier units 2-2 to 2- n also has the same configuration as that of the rectifier unit 2-1 described below.
The rectifier unit 2-1 includes an FIL unit 2-1a, a PFC unit (rectifier circuit having a power factor improving function) 2-1b, an αC-DC unit 2-1c, a voltage dividing circuit 2-1d, and a conversion control unit 2- 1f and a diode 2-1g.
The FIL unit 2-1a is composed of a low-pass filter, and removes noise superimposed on the waveform of the alternating current input from the commercial power source 100. The PFC unit 2-1b is a rectifier circuit having a power factor improvement function by high-frequency switching.
The DC-DC unit 2-1c is input according to the duty ratio of the drive pulse output from the conversion control unit 2-1f (ratio of the “H” level period and the “L” level period in one cycle of the pulse). DC voltage corresponding to the duty ratio is converted to a DC voltage having a stable voltage value.

  In the voltage dividing circuit 2-1d, for example, resistors R1 (resistance value r1), R2 (resistance value r2), and R3 (resistance value r3) are output via the output of the DC-DC unit 2-1c (diode 2-1g). Switch 2 is connected in series between the positive side terminal of the rectifier unit and the negative side terminal of the rectifier unit. At the connection point P of the resistors R2 and R3 and the negative side terminal of the rectifier unit, the switch 2 -1e is connected in parallel with the resistor R3. The divided voltage output from the voltage dividing circuit 2-1d is a voltage at a connection point Q between the resistors R1 and R2. When the switch 2-1e is opened (non-conducting state), the divided voltage value at the connection point Q is Vins = Vh · (r2 + r3) where Vh is the voltage output from the DC-DC unit 2-1c. ) / (R1 + r2 + r3). On the other hand, when the switch 2-1e is closed (conducting state), the resistor R3 is canceled, so that the divided voltage value at the connection point Q is Vdis = Vh · (r2 ) / (R1 + r2). Here, a switch is used, but a relay, a contactor, a semiconductor switch (for example, a transistor), or a circuit breaker that can be opened and closed by an external signal may be used.

Here, by setting the resistance values of the resistors R1 to R3 so that Vdis> Vins at the same Vh, the conversion control unit 2-1f closes the switch 2-1e (conduction state). ) To open (non-conducting state), the voltage value of the output voltage of the rectifier unit 2-1 is controlled to a lower voltage value than in the closed state.
The conversion control unit 2-1f includes an amplifier circuit 2-1f1, a comparator 2-1f2, a drive circuit 2-1f3, a reference voltage source 2-1f4, and a triangular wave generation circuit 2-1f5.
The amplifier circuit 2-1f1 controls the divided voltage value input from the voltage dividing circuit 2-1d and the reference voltage value output from the internal reference voltage source 2-1f4 (the output voltage is controlled to a preset voltage value). And the difference is amplified and output to the comparator 2-1f2 in the next stage.
In the amplifier circuit 2-1f1, the reference voltage value is applied to the non-inverting input terminal (+), the resistor R4 is connected between the inverting input terminal (−) and the output terminal, and the resistance is connected to the inverting input terminal (−). The divided voltage value is input via R5.

The comparator 2-1f2 compares the voltage value obtained by amplifying the difference between the reference voltage value and the divided voltage value by the amplifier circuit 2-1f1 with the voltage value of the triangular wave output from the triangular wave generation circuit 2-1f5. The drive circuit 2-1f3 is a pulse in which the time width of the voltage value of the triangular wave exceeding the amplified voltage value is “H” level and the time width of the voltage value of the triangular wave less than the amplified voltage value is “L” level. Output for.
The drive circuit 2-1f3 outputs the input pulse as a drive pulse to the DC-DC unit 2-1c.
The DC-DC unit 2-1c increases the voltage value of the output voltage as the period of the “H” level becomes longer in the duty ratio (duty ratio) of the input drive pulse.

That is, if the divided voltage value output from the voltage dividing circuit 2-1d is higher than the reference voltage, the conversion control unit 2-1f determines that the voltage value of the preset output voltage is output, and the DC-DC The period of the “H” level of the drive pulse for the part 2-1c is shortened.
For this reason, when the detection voltage value rises by opening the switch 2-1e from the closed state, the conversion control unit 2-1f is less than the preset output voltage value during operation, and the diode 2-1g A drive pulse is output to the DC-DC unit 2-1c so that the DC-DC unit 2-1c outputs a voltage value (standby voltage value) that turns off.
Since the output of the DC-DC unit 2-1c is connected at the connection point A through the diode, the rectifier unit 2-1 that has stopped the output of the DC power is connected from the closed to the open state. Since the output voltage is a standby voltage value, and the diode 2-1g is turned off lower than the operating voltage value output by another operating rectifier unit, the diode 2-1g has an anode-to-cathode direction. A state in which no current flows is made, and the DC power output is stopped.
Therefore, the operation number control unit 5 controls each rectifier unit switch to open / close so that the calculated operation number is obtained, thereby setting each switch unit to an operating state or a standby state.
That is, the operating number control unit 5 controls the voltage dividing ratio of each voltage dividing circuit of the rectifier units 2-1 to 2-n, increases the detected voltage value compared to before voltage dividing, and sets the voltage value of the output voltage. The DC power output of the rectifier unit is stopped by lowering it compared to the output voltage during operation.
In the present embodiment, the B contact type switch 2-1e is used in the voltage dividing circuit 2-1d. However, the A contact type switch of the voltage dividing circuit 2-1d described in the frame Z is used. It is good also as a structure using 2-1e.
That is, in the voltage dividing circuit 2-1d in the frame Z, the detected voltage value input to the inverting input terminal (−) of the amplifier circuit 2-1f1 is output from the connection point Q between the resistors R2 and R3. Is done. The switch 2-1e is connected between a connection point P between the resistors R1 and R2 and a connection point Q between the resistors R2 and R3. Therefore, when the voltage dividing circuit 2-1d of the frame Z is used, contrary to the switching control of the switch described above, when the rectifier unit is put into operation, the switch 21e is opened and the output voltage of the rectifier unit is opened. The output voltage is output from the rectifier unit. On the other hand, when the rectifier unit is stopped, the switch 21e is closed, the detected voltage value is increased compared to the operating state, the output voltage of the rectifier unit is decreased to the standby voltage value, and the diode 2-1g Is turned off and the DC power output of the rectifying unit is stopped.

Next, the operation number control unit 5 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 5 in FIG.
The operating number control unit 5 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 reads, via the input unit 11, the operating number table in which the current value of the load current and the operating number that minimizes the power loss at the current value are indicated, and the storage unit 14. Are stored in advance before the operation of the DC power supply.
Further, the control unit 15 stores the current value of the load power input from the current measurement unit 4 in the storage unit 14 in time series corresponding to the read time, and when calculating the number of operating units in the control cycle, The current value of the load power corresponding to the latest time is read from the storage unit 14 and output to the calculation unit 12.

The timer 13 counts the time, and outputs the cycle notification signal to the control unit 15 when the operation cycle control unit 8 controls the operation unit number of rectifiers.
The calculation unit 12 reads the number of operating units corresponding to the current value of the load current 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 operating number table is configured to stop the rectifier unit in order to obtain the current value of the load current and the operating number with the smallest power loss at this load current ( It is a table which shows a response | compatibility with the number of stops. 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 2-1 to 2-n is connected to a plurality of the rectifier units 2-1 to 2-n in parallel for the purpose of voltage control (CV) with a constant and the same voltage as a target. The current value obtained by dividing the load current output by the number of operating units is distributed evenly 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 rectifier 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 (for example, a table showing the loss corresponding to the load current), and the rectifier is divided into each. Multiply the number of units to calculate the total power loss for each unit. 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 number of rectifier units with the smallest 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 ILunit 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 ILmax 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 4 reads the current value of the load current output from the current sensor 4 for each preset period and outputs it to the operating number control unit 5.
The control unit 15 writes the current value of the input load current 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 current stored in the storage unit 14, that is, the latest current value. Read and output to the calculation unit 12.
d. The calculation unit 12 reads out the number of stops corresponding to the current value of the input load current from the operating number table of the storage unit 14 and outputs it to the control unit 15.
e. In the current DC power supply device, the control unit 15 has the same number of stops as input from the calculation unit 12, so that the voltage divider circuit switches in each rectifier unit are closed (conductive state) and open (non-conductive state). I do.
B. ~ E. This process is performed for each cycle and each control cycle. a. Is repeatedly performed at a preset control cycle period.

In the above e, for example, when the DC power supply device has eight rectifier units 2-1 to 2-8, and the number of currently stopped units is three (2-1 to 2-3), Are input from the arithmetic unit 12 as four units, the control unit 15 opens the switches in the voltage dividing circuit of the rectifier unit 2-4 in numerical order, and outputs four units from the rectifier units 2-1 to 2-4. Set to the stop state. On the other hand, when the number of stops is input from the calculation unit 12 as two units, the control unit 15 closes the switches in the voltage dividing circuit of the rectifier unit 2-3 in numerical order, operates the rectifier unit 2-3, and operates the rectifier unit. Control is performed to stop the output of two units 2-1 and 2-2.
As described above, according to the present embodiment, the load current supplied to the load facility 200 operates in the state where the total loss of the current units provided in the DC power supply device is the smallest, that is, the state where the power conversion efficiency is the highest. It is possible to suppress wasteful consumption of electrical energy.
In this embodiment, as shown in the table of FIG. 3, when the load current is 0, all the units, that is, the switches of the eight rectifier units are opened, and the output of all the rectifier units is stopped. It is the composition which becomes a state. However, even when the current value of the load current is 0, the switches of each of the seven rectifier units are opened so that the total loss of the rectifier units is the smallest when the number of operating units is one. The switch of the rectifier unit may be closed, and even when the current value of the load current is 0, at least one rectifier unit may be in an operating state.

Further, as shown in FIG. 4, each rectifier unit has a characteristic that the output voltage decreases as the load capacity of the connected load equipment 200 increases (impedance decreases).
For example, if two units of rectifier units 2-1 and 2-2 are provided in the DC power supply device and each rectifier unit is operating at 40% output, it operates at 80% output with one rectifier unit. Since the conversion efficiency is better, it shows a state in which one of the rectifier units 2-1 is operated. Here, the load factor [%] is a ratio of the load current value output from the rectifier unit to the unit maximum output current value of the rectifier. In FIG. 4, the horizontal axis represents output, and the vertical axis represents output voltage.

Line L1 indicates the output characteristic of the rectifier unit 2-1 that outputs the load current, and line L2 indicates the output characteristic of the rectifier unit 2-2 that stops the output of the load current.
At this time, when the load capacity is suddenly reduced and the load current is increased except at the time of performing the operation number control process in the control cycle, the current operation number (one of the rectifier units 2-1) is insufficient in the load current. Then, the voltage value of the output voltage at the output terminal of the DC power supply device decreases from the constant voltage value Vn (operating voltage value).
Here, the standby voltage value of the output voltage output from the rectifier unit that has stopped operating is set as the voltage value V <b> 1 that falls within the operating range voltage range of the load facility 200.

As a result, even if the load capacity of the load facility 200 suddenly increases, the load current increases, and the operating voltage value that is the voltage value of the output voltage of the rectifier unit in the operating state decreases from the constant voltage value Vn, When the voltage value decreases to the voltage value V1, the diode of the stopped rectifier unit is turned on and the current starts to flow, so that all the rectification units in the DC power supply device start the operation with the output voltage as the voltage value V1. It becomes a state of sharing and supplying.
As a result, even if the load capacity changes abruptly, the voltage value V1 of the operating range voltage is supplied from the DC power source to the load facility 200, so that the load facility 200 will not stop due to a change in the load current. Instead, as shown in FIG. 5, a stable operating state can be maintained until the number of operating units is controlled in the next control cycle. In FIG. 5, the horizontal axis represents time, and the vertical axis represents the voltage value of the output voltage.

In order to perform the above-described operation, the output voltage of the rectifier unit is set to the voltage value V1, that is, Vins = V1 · (r2 + r3) / (r1 + r2 + r3) and Vcon = Vn · (r2) / (r1 + r2) Therefore, it is necessary to set the resistance value r1 of the resistor R1, the resistance value r2 of the resistor R2, and the resistance value r3 of the resistor R3.
Thereby, the detected voltage value is set so that the voltage value V1 is included in the voltage range in which the load facility 200 operates.

<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. 6, 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 closed switches, outputs the current number of operating rectifier units n _t to the computing unit 12, and simultaneously, measures the current measuring unit 5. _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. 7. 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 opening / closing control of a switch so that it may become the working number input from the calculating part 12, similarly to 1st Embodiment.

Further, as shown in FIG. 8, the order of processing of steps S4 and S5 and step S6 and S7 in the flowchart of FIG. 7 is changed, and similarly, the order of steps S9 and S8 is changed, and the power loss P _lossn is changed. 7 is _first determined whether or not the power loss is less than the power loss P _lossn−1 , and then it is determined whether or not the power loss is smaller than the power loss. The number of operating rectifier units with the smallest loss can be obtained.
Further, as shown in FIG. 9, step S8 is performed between step S5 and step S6 in the flowchart of FIG. 7, 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. 9, the number of operating rectifier units with the smallest power loss can be obtained as in the processing of the flowchart of FIG. 7.
Also, as shown in FIG. 10, the order of processing of steps S4 and S5 and steps S6 and S7 in the flowchart of FIG. 7 is changed, step S9 is performed between step S7 and step S4, and step 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. 10, the number of operating rectifier units with the smallest power loss can be obtained as in the processing of the flowchart of FIG. 7.

  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 graph which shows a response | compatibility with the output [%] and output voltage of each 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 ... Rectifier unit 2-1a ... FIL part 2-1b ... PFC part 2-1c ... DC-DC part 2-1d ... Voltage dividing circuit 2-1e: Switch 2-1f: Conversion control unit 2-1f1: Amplifier circuit 2-1f2: Comparator 2-1f3: Drive circuit 2-1f4: Reference voltage source 2-1f5 ... Triangular wave generation circuit 3 ... Current sensor 4 ... Current measuring unit 5 ... Number of operating units control unit 9 ... Output terminal 11 ... Input unit 12 ... Calculation unit 13 ... Timer 14 ... Storage unit 15 ... Control unit 100 ... Commercial power source 200 ... Load facility

Claims (6)

A plurality of rectifier units connected in parallel with an output terminal for inputting AC power and outputting DC power;
A current sensor that measures the current value of the DC power and outputs the current value of the DC power;
The number of operating rectifier units that minimize the loss of conversion from AC to DC in each rectifier unit according to the current value, and the number of operating units is controlled so that DC power is output from the rectifier units of the operating number And
The rectifier unit compares a detection voltage value obtained by dividing its own output voltage by a voltage dividing circuit with a preset reference voltage, controls the output voltage, and outputs the output voltage via a diode, The DC power supply device, wherein the operation number control unit controls operation of the rectification unit corresponding to the operation number by controlling a voltage dividing ratio of a voltage dividing circuit.   The operating number control unit controls the voltage dividing ratio of the voltage dividing circuit, increases the detected voltage value compared to before voltage dividing, and reduces the voltage value of the output voltage compared to the operating output voltage. The DC power supply device according to claim 1, wherein the operation of the rectifier unit is stopped by the operation. The divided circuit is configured by connecting resistors in series, and a switch is connected in parallel with any of the resistors,
3. The DC power supply device according to claim 1, wherein the operating number control unit controls the voltage dividing ratio of the voltage dividing circuit by controlling the switching of the switch. 4.   The detection voltage value is set so that the voltage value of the output voltage is included in a voltage range in which the load can operate (input voltage range of the load). The direct current power supply device described. The operating number control unit is
An operating number table in which the current value of the DC power and the operating number of the rectifier unit with the minimum conversion loss 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;
5. The DC power supply device according to claim 1, further comprising: a control unit that controls the switch according to the number of operating units calculated 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,
5. The DC power supply device according to claim 1, further comprising: a control unit that controls the switch according to the number of operating units calculated by the calculation unit.

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