JP3461678B2 - DC power supply device and control method thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC power supply device and method having a backup function suitable for use as a communication power supply.

[0002]

2. Description of the Related Art Since a power supply device for communication such as a telephone is not allowed to cut off power, it is equipped with a storage battery as a backup power supply for supplying power to a load circuit at the time of power failure or failure of the regular power supply. Recently, in order to improve the reliability of the storage battery power source, there is a storage battery in which a plurality of storage battery cells are connected in series and connected in parallel to perform a redundant operation. In this case, for example, two parallel storage batteries are alternately discharged every few months until the discharge is close to the discharge end voltage, and the deterioration thereof is determined.

A typical conventional DC power supply device of this kind is shown in FIG. In FIG. 3, reference numeral 1 is an AC power source such as a commercial power source, and 2 is a rectifying device having a control function of rectifying the AC power source from the AC power source 1 to generate a constant output voltage. Generally, a small-sized one that switches a switching semiconductor element such as a power MOSFET by high-frequency pulse width control is used. 3 is a backflow prevention element, 4 is a load circuit including a DC-DC converter and a load connected to its output side, 5 is a power supply line from the rectifier 2 to the load circuit 4, and 6A and 6B are connected in parallel. A redundantly operated storage battery, 7 is a selective discharge circuit for the storage batteries 6A and 6B, 8 is a CPU that gives a signal for operating the selective discharge circuit 7 or a control signal for controlling the charging circuit 21, 22 and 23 are charging resistors, 24 And 25 are diodes for backflow prevention.

The charging circuit 21 is a constant voltage control unit 21A for charging the storage batteries 6A and 6B to a predetermined voltage.
And a constant current controller 21B for applying a constant current to the storage batteries 6A and 6B. The constant voltage control unit 21A of the charging circuit 21 uses the output voltage of the rectifier 2 and the storage batteries 6A and 6B.
It shares the voltage difference with the terminal voltage. For example, if the output voltage of the rectifying device 2 is controlled to be approximately 15.5V and the floating charging voltage of the storage batteries 6A and 6B is set to about 13.5V, the charging circuit 21 outputs about 2V in this floating charging state.
A voltage drop occurs, and power consumption corresponding to the product of the voltage and the charging current is performed.

The storage battery 6A is in a floating charge state, and the storage battery 6B is discharged to the discharge end voltage, which is the lowest voltage at which the storage battery 6A does not discharge any more, in order to judge its deterioration, and then is charged again. Assuming that the voltage returns to the original voltage after a charging time of about 10 to 20 hours, the constant current control unit 21B during that time performs a constant current charge on the storage battery 6B, and thus initially functions as a dropper with a large resistance. However, the resistance decreases as charging progresses. Therefore, in addition to the power consumption of the constant voltage controller 21A, the constant current controller 21B during this period consumes a considerable amount of power.

Further, as a result of the occurrence of a failure on the input power source side such as a rectifying device, the storage batteries 6A and 6B supply power to the load circuit 4 during the power failure period, and as a result, the storage batteries 6A and 6B reach the discharge end voltage, for example, 10.2V. When the storage battery 6A and 6B in this state are charged, the charging circuit 21 bears a voltage of a little over 5V at the beginning of charging, which results in considerable power consumption.

[0007]

As is clear from the above description, since considerable power loss occurs in the conventional charging circuit, not only the efficiency of the entire power supply device is lowered, but also the device is generated due to heat generation. There are problems such as making it difficult to downsize.

[0008] Furthermore, since the power loss of the charging circuit is large during the period for charging the storage battery after discharging when the power failure is restored on the input power supply side or when the deterioration of the storage battery is determined, the charging circuit consumes much more power than the normal floating charging period. Due to these short power failures and the increase in power capacity during the charging period after the deterioration determination,
There is no choice but to increase the output capacity of the rectifying device 2, and it is difficult to suppress the power capacity to 50 VA, which has a low power-receiving contract fee.

[0009]

According to a first aspect of the present invention, in order to solve the above problems, a rectifier for converting AC input power into DC power and a power supply in which a backflow prevention element is inserted. A load circuit connected to the output of the rectifier through a line, and a backup power supply point of a power supply line between the backflow prevention element and the load circuit, connected through respective switch elements, and connected in parallel with each other. Power supply line between the output terminal of the rectifying device and the backflow prevention element, comprising: two or more sets of storage batteries provided to supply power to the load circuit without interruption. And a plurality of unidirectional impedance circuits connected between the respective positive and negative electrodes of the storage battery, and a voltage drop across the unidirectional impedance circuit, Regardless of the size of the terminal voltage of the storage battery, the terminal voltage of each of the storage batteries is detected in order to reduce the charging power loss to a predetermined constant voltage value or less, and the most of the detected voltages is detected. C for controlling the rectifying device to output a voltage higher than the terminal voltage of the storage battery having a low voltage value by a predetermined voltage
A DC power supply device including a PU is provided.

According to a second aspect of the present invention, in order to solve the above-mentioned problems, in the first aspect, when the DC power is supplied from the output terminal of the rectifying device to the load circuit, the CPU
Provides a DC power supply device that turns off the switch element to prevent power from being supplied from the storage battery to the load circuit.

According to a third aspect of the present invention, in order to solve the above-mentioned problems, in the first or second aspect, when the output voltage of the rectifying device drops below a predetermined set voltage, the CPU causes the switch element to operate. The present invention provides a DC power supply device that turns on the power supply to supply power from the storage battery to the load circuit.

According to a fourth aspect of the present invention, in order to solve the above-mentioned problems, in any one of the first to third aspects, the parallel connection is performed when the output voltage of the rectifying device drops below a predetermined set voltage. When the terminal voltages of the two or more storage batteries are different, the CPU first turns on the switch element connected to the storage battery having a high terminal voltage, and when the terminal voltages of the storage batteries become substantially equal, A DC power supply device for turning on the switch element connected to the storage battery having a substantially equal voltage.

According to a fifth aspect of the present invention, in order to solve the above-mentioned problems, in any one of the first to fourth aspects, a switch means is connected in series to each of the plurality of unidirectional impedance circuits, and the CPU is The present invention provides a DC power supply device that disperses charging power by sequentially closing the switch elements and sequentially charging the storage batteries when the power supply recovers from the input power source.

A sixth aspect of the present invention is, in order to solve the above-mentioned problems, according to any one of the first to fifth aspects, a selective discharge circuit is provided between terminals of the storage battery, and the CPU includes:
Disclosed is a DC power supply device that periodically or irregularly supplies a discharge signal to the selective discharge circuit to sequentially discharge the storage batteries and determine deterioration from the discharged state.

According to a seventh aspect of the present invention, in order to solve the above-mentioned problems, a DC power supply device that sequentially performs deterioration determination and charging of another storage battery after completion of charging of the storage battery for which deterioration determination has been performed in the sixth aspect. Is provided.

According to a eighth aspect of the present invention, in order to solve the above-mentioned problems, in the sixth or seventh aspect, a switch means is connected in series to each of the plurality of unidirectional impedance circuits, and any one of the storage batteries is connected. The CPU provides a DC power supply device that turns off the switch means when discharging and determining its deterioration.

In order to solve the above-mentioned problems, a ninth aspect of the present invention provides the direct-current power supply device according to the fifth or eighth aspect, wherein the CPU turns off the switch means during a battery deterioration determination test. is there.

According to a tenth aspect of the present invention, in order to solve the above-mentioned problems, in any one of the first to ninth aspects, the unidirectional impedance circuit is a DC power supply device including a resistor and a diode connected in series. Is provided.

In order to solve the above-mentioned problems, the eleventh aspect of the present invention is connected to the output of the rectifier through a rectifier that converts AC input power into DC power and a power supply line in which a backflow prevention element is inserted. Load circuit, and two or more sets of storage batteries connected in parallel to each other, which are connected to backup power supply points of a power supply line between the backflow prevention element and the load circuit through respective switch elements. Then, in the control method of the DC power supply device for supplying power to the load circuit uninterruptibly, the terminal voltage of each of the storage batteries is detected, and the terminal voltage of the storage battery and the rectifier of the lowest of the detected voltages. The voltage difference from the output voltage is set to be equal to or less than a predetermined small fixed value capable of reducing charging loss regardless of the terminal voltage of the storage battery. The present invention provides a method of controlling a DC power supply device, which is characterized by controlling a rectifying device.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram for explaining a first embodiment of the present invention, and the same symbols as those shown in FIG. 3 indicate corresponding members. In FIG. 1, reference numerals 9 and 10 denote first and second unidirectional impedance circuits composed of a resistor having an appropriate value and a diode such as a Schottky barrier diode having a small forward drop. A constant current circuit is constructed in cooperation with the controlled rectifying device 2. Further, 11 and 12 are switch elements whose on / off are controlled by the CPU 8 such as a computer, and semiconductor elements such as FETs or bipolar transistors are used.

Next, before describing the operation of this DC power supply device, the characteristics of the operation will be described. The terminal voltage of each storage battery that is operated in a redundant manner is detected, and the storage battery 6A or the storage battery 6A having a lower detection voltage is detected. The rectifier 2 is controlled so as to output a voltage higher than the terminal voltage of 6B by a predetermined voltage (for example, 1.0 V), and constant current charging with small power loss is performed through the charging path having a very simple structure. However, the switch elements 11 and 12 are members newly provided to enable this.

First, a state in which electric power is supplied to the load circuit 4 while the storage batteries 6A and 6B are floating-charged will be described. When the set voltage of the floating charge is, for example, about 13.5V, and the terminal voltages of the storage batteries 6A and 6B are both about 13.5V, the CPU 8 outputs the output voltage of the rectifier 2 from 13.5V. Is controlled to a voltage higher by a predetermined voltage, for example, 14.5V higher by 1.0V. The output voltage is input to the DC / DC converter (not shown) of each communication line of the load circuit 4 through the backflow prevention element 3, and the unidirectional impedance circuits 9 and 1 are also provided.
The charging current is the storage batteries 6A, 6B through the charging path consisting of 0
Flows to. At this time, the unidirectional impedance circuits 9 and 1
If the impedance of 0 is R, the charging current i _c is 1
Since V / R and R are constant, the charging current i _c becomes a constant current, and the storage batteries 6A and 6B are charged with a constant current.

At this time, the output voltage of the rectifier 2 is 1
Since it is 4.5V, and the terminal voltages of the storage batteries 6A and 6B are both about 13.5V, the voltage drop of the unidirectional impedance circuits 9 and 10 is about 1.0V, and the power loss thereof is 1V. Since it is the product of the voltage of 0.0 V and the charging current, it is clear that if the charging current is set to the same level as in the conventional case, it becomes smaller than in the conventional case. This means that the output voltage of the rectifying device 2 can be lowered by 1 V or more compared with the conventional one, so that the rectifying device 2
The efficiency can be improved, and at the same time, the output capacity can be reduced. Further, since the rectifying device 2 and the unidirectional impedance circuits 9 and 10 form a constant current circuit, a complicated charging circuit as in the past can be omitted.

Next, while performing the floating charging,
A battery deterioration determination test shall be conducted on a regular basis. With the signal from the CPU 8, if only one of the switches 7B and 7C of the selective discharge circuit 7, here the switch 7B, is closed for a predetermined time,
The storage battery 6A is discharged through the discharge circuit 7A until the discharge end voltage value is almost reached, and the CPU 8 determines whether the storage battery 6A is deteriorated based on whether the discharge state is normal or abnormal. CPU8
When it is determined that the storage battery 6A is normal, the output voltage of the rectifying device 2 is set to a predetermined voltage value, for example, 1 V in this example, which is lower than the discharge end voltage value of 10.2 V of the storage battery 6A having the lower voltage. If it is set to 0.0V, the voltage will be higher by 1.0V 1
Control to 1.2V.

Therefore, in this case, the output voltage of the rectifier 2 becomes a voltage of 11.2V, and the voltage drop of the unidirectional impedance circuit 9 becomes about 1.0V even at the initial charging of the storage battery 6A. The power loss is much smaller than before. At this time, the terminal voltage of the storage battery 6B is maintained at approximately 13.5 V, so the diode of the unidirectional impedance circuit 10 is reverse biased. Therefore, the storage battery 6B is not discharged to the output point X side of the rectifier 2. Then, as the charging voltage of the storage battery 6A becomes higher, the CPU 8 always controls the rectifying device 2 so as to output a voltage higher by 1.0V, which is a predetermined voltage value than the charging voltage of the storage battery 6A. Therefore, the storage battery 6A
The voltage drop of the unidirectional impedance circuit 9 is always about 1.0 V regardless of the increase in the charging voltage of the.

What is important here is that at least the switch element 12 is turned off, that is, opened when the storage battery 6A is discharged. The reason for this is that the output voltage of the rectifying device 2 in the initial stage of charging is 11.2 V, and the voltage at the backup power supply point Y of the power supply line 5 is
This is because the terminal voltage of the storage battery 6B is lower than 13.5 V, so that the storage battery 6B is prevented from being discharged to the load circuit 4. Therefore, in the case of battery deterioration judgment test,
Prior to the test, at least the switch element 11 or 12 connected to the storage battery on the non-test side needs to be turned off. This is done by the software of the CPU 8.

In this charging state, as the set discharge voltage value of the storage battery 6 A, for example, 10.2 V which is the discharge end voltage value, increases, the output voltage of the rectifying device 2 also increases under the control of the CPU 8. As the output voltage of the rectifier 2 increases,
Although the input voltage of the load circuit 4 also rises, since the DC-DC converter included in the load circuit 4 performs a constant voltage operation, a constant voltage is effectively supplied to the load. Also,
If the load allows voltage fluctuation within a certain range, a local power source such as a DC-DC converter may not be required.

The case where the battery deterioration determination test of the storage battery 6B is performed is exactly the same as the case of the storage battery 6A, so the description is omitted. However, after the deterioration determination, the storage battery 6A is charged to about 13.5V which is almost fully charged. Immediately after that, the battery deterioration determination test of the storage battery 6B is performed.

Next, a case where a power failure or a failure occurs on the input power source side including the rectifying device 2 will be described. Rectifier 2
When the output voltage of the rectifier 2 drops below a predetermined voltage value, the CPU 8 detecting the output voltage of
The input power source side determines that there is a power failure, and if the terminal voltages of the storage batteries 6A and 6B are substantially equal, the switch elements 11 and 12 are given an ON signal at about the same time to turn them ON, and at the same time the rectifying device 2 is stopped. When the switch elements 11 and 12 are turned on, the storage batteries 6A and 6B start supplying power to the load circuit 4 via the switch elements 11 and 12, respectively. In the floating charging state, the charging voltages of the storage batteries 6A and 6B are substantially equal, but during the transient charging process immediately after the battery deterioration determination test of any of the storage batteries, there is a difference in the terminal voltage of the storage batteries 6A and 6B. .

As described above, when the terminal voltages of the storage batteries 6A and 6B are not equal to each other, the switch element 11 or 12 connected to the storage battery having the higher terminal voltage is first turned on to transfer the storage battery to the load circuit 4. When electric power is supplied and the terminal voltage of the storage battery drops to a value approximately equal to the voltage of the other storage battery, the other switching element 12 or 1
1 is turned on, and power supply is also started from the storage battery. The switch elements 11 and 12 are preferably FETs, and if necessary, a Schottky barrier diode having a small forward drop may be connected in series.

Then, when the recovery from the power failure or the failure on the input power source side is prolonged and the terminal voltage of the storage batteries 6A and 6B drops to the discharge end voltage, the CPU 8 causes the switching elements 11 and 12 to operate.
An off signal is applied to both of them to turn them off, so that these switch elements also function as a conventional overdischarge preventing switch. . Further, regardless of the terminal voltages of the storage batteries 6A and 6B, when the input power supply side normally returns, the CPU
Reference numeral 8 applies an OFF signal to the switch elements 11 and 12 to turn them off, that is, to open them. CPU8 is storage battery 6
The rectifier 2 is controlled so as to detect the terminal voltages of A and 6B and output a voltage higher than the terminal voltage of the lower storage battery by a predetermined voltage as described above. In this case, these terminal voltages are controlled. Are substantially equal to each other, power is supplied to the load circuit 4 at an output voltage higher than the terminal voltage of the storage batteries 6A and 6B by a predetermined voltage, and the storage batteries 6A and 6B are supplied with a constant current through the unidirectional impedance circuits 9 and 10, respectively. To charge. At this time, the unidirectional impedance circuits 9, 10
The voltage drop across the voltage is approximately the predetermined voltage, and if the voltage is set to, for example, 1.0 V, the power loss during this charging period can be made considerably smaller than in the conventional case. In addition, the storage batteries connected in parallel and operated redundantly have three, four, ...
... The same applies to the case of N pieces.

Next, another embodiment of the present invention will be described with reference to FIG. This is the FE connected in series to each of the unidirectional impedance circuits 9 and 10 in the embodiment shown in FIG.
It is characterized in that switching means 13 and 14 such as T are connected and ON / OFF control is performed as follows.

When the input power source is restored from a power failure, both storage batteries 6A and 6B are simultaneously charged with a constant current through the unidirectional impedance circuits 9 and 10 as described above.
The output capacity of the rectifier 2 has to be increased, which can be very disadvantageous in terms of economy. In addition, the fact that the output capacity of the rectifying device 2 must be increased means that the input capacity becomes large, and from the aspect of contracted power, the load capacity must be limited in accordance with the restoration from the power failure.

Therefore, in this embodiment, one of the switch means 13 and 14 connected in series with the unidirectional impedance circuits 9 and 10 is turned on by the ON signal from the CPU 8 when the power supply recovers from the input power supply side, and the other is turned off. In the state, that is, in the open state, only one of the storage batteries 6A or 6B is first charged, and after the charging is completed, the other switch means is closed to charge the other storage battery. By performing such charging, charging power is dispersed.
Even when the number of parallel storage batteries is N, by sequentially turning on and off the switching means and performing sequential charging, the charging power for a single time during charging can be reduced to approximately 1 / N. It is possible.

Further, an advantage of this embodiment is that the storage battery 6
This means that the battery deterioration determination tests of A and 6B can be performed accurately. In order to accurately measure the discharge current of the storage batteries during the deterioration determination test, if the storage battery to be subjected to the deterioration determination test is 6A, the CPU 8 uses the discharging switch 7
An ON signal is given to B to close it, and at the same time, the switch means 13
An off signal is given to the terminal to open it. By turning off the switch means 13, the rectifying device 2 and the storage battery 6A are disconnected from each other, and the charging current is prevented from flowing when the storage battery 6A is discharged, whereby the discharge current can be accurately measured. Then, when the deterioration determination is performed, the storage battery 6A is charged again, so CP
U8 gives an ON signal to the switch means 13 to turn it on, and at the same time gives an OFF signal to the switch 7B to open it. When semiconductor elements such as FETs and transistors are used as the switch means, unidirectional semiconductor elements such as diodes can be omitted from the unidirectional impedance circuits 9 and 10.

In the power supply system of the present invention, the storage battery having a higher terminal voltage that has been floating-charged has a period in which it is not charged due to the battery deterioration determination, but this period is 10 to 20 hours at the longest. As such, there is practically no adverse effect. In addition, the voltage value of each part described above is
This is merely an example, and it goes without saying that an arbitrary voltage may be used.

[0037]

As described above, the present invention eliminates the conventional charging circuit having a constant voltage and constant current function, and the rectifying device has the terminal of the lowest voltage battery among the batteries connected in parallel. Since a voltage higher than the voltage by a predetermined voltage is output, constant-current charging with low power loss can be performed using an inexpensive unidirectional impedance circuit with an extremely simple configuration consisting of a resistor and a diode connected in series. ,
Since the output voltage of the rectifier can be lowered, the efficiency can be improved accordingly.

In addition, since the voltage borne by the charging path can be made lower than that of a conventional charging circuit having a constant voltage and constant current function, the power loss thereof can be considerably reduced, and not only the efficiency but also the size reduction. Is possible.

Furthermore, since the charging path is provided with the switch means and the opening / closing control is performed, the charging power of the storage battery after the recovery from the power failure on the input power source side can be dispersed, so that the input capacity of the DC power supply device can be reduced. There is a large drop in practical use.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a first embodiment of the present invention.

FIG. 2 is a diagram for explaining a second embodiment of the present invention.

FIG. 3 is a diagram for explaining a conventional example.

[Explanation of symbols]

1 ... AC input power supply 2 ... Rectifier 3 Backflow prevention element 4 ... Load circuit 5 ... Power supply line 6A, 6B ... Storage battery 7 ... Selective discharge circuit 8 ... CPU 9, 10 ... Unidirectional impedance circuit 11, 12 ... Switch element 13, 14 ... Switch means

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Kii 1-18-1 Takada, Toshima-ku, Tokyo Inside Orizin Electric Co., Ltd. (72) Inventor Seiichi Muroyama 3-19-3 Nishishinjuku, Shinjuku-ku, Tokyo No. 2 Nihon Telegraph and Telephone Corporation (72) Inventor Takashi Yamashita 3-19-2 Nishishinjuku, Shinjuku-ku, Tokyo Nihon Telegraph and Telephone Corporation (56) Reference JP-A-4-281339 (JP, A) ) JP-A-6-342327 (JP, A) JP-A-60-28731 (JP, A) Actual Kaihei 1-64938 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02J 7/00-7/34 H02J 1/00

Claims (11)

(57) [Claims] And 1. A rectifier for converting an AC input power into DC power, and a load circuit connected through via interpolated power supply line of the backflow prevention device to an output of the rectifier, and the reverse current prevention element Power to and from the load circuit
Each backup power supply point on the
Is connected through switch elements, comprises a, and two or more sets of storage batteries connected in parallel to each other, in a DC power supply for supplying power uninterruptible to said load circuit, wherein an output terminal of the rectifier reflux Between the protection element
And said power supply line, and a plurality of unidirectional impedance circuit connected between each of the positive electrode also <br/> the negative electrode of the battery, the voltage drop across said unidirectional impedance circuit,
Regardless of the terminal voltage of the storage battery, charging power
Below a certain fixed voltage value that can reduce loss
To detect the battery respective terminal voltages,
DC power supply, comprising: a CPU that controls the rectifying device to output a voltage that is higher than the terminal voltage of the storage battery having the lowest voltage value among the detected voltages by a predetermined voltage. apparatus. 2. The CPU according to claim 1, wherein when the DC power is supplied from the output terminal of the rectifier to the load circuit, the CPU turns off the switch element to supply power from the storage battery to the load circuit. A DC power supply device, characterized in that it is prevented from being supplied. 3. The CPU according to claim 1, wherein when the output voltage of the rectifying device drops below a predetermined set voltage, the CPU turns on the switch element to shift the storage battery to the load circuit. Power will be supplied
DC power supply and wherein the Unisuru. 4. The terminal voltage of the two or more sets of storage batteries connected in parallel according to any one of claims 1 to 3, when the output voltage of the rectifying device drops below a predetermined set voltage. When different, the CPU first turns on the switch element connected to the storage battery having a high terminal voltage, and when the terminal voltage of the storage battery becomes substantially equal,
Before connecting to the storage battery whose terminal voltage is almost equal
A DC power supply device characterized by turning on a switch element . 5. The switch unit according to claim 1, wherein a switch means is connected in series to each of the plurality of unidirectional impedance circuits, and the CPU has an input power source side.
After the power failure of
A DC power supply device, characterized in that charging power is dispersed by sequentially charging a pond . 6. The CPU according to claim 1, further comprising a selective discharge circuit provided between terminals of the storage battery,
Periodically or irregularly sends a discharge signal to the selective discharge circuit.
A DC power supply device, characterized in that the storage battery is sequentially discharged to determine deterioration from the discharged state . 7. The method of claim 6, deterioration after completion of charging performed the storage battery of the determination, the DC power supply apparatus characterized by sequentially performing the charging and deterioration determination of other batteries. 8. The method according to claim 6 or 7, wherein a switch means is connected in series to each of the plurality of unidirectional impedance circuits, and any one of the storage batteries is discharged to determine its deterioration. The DC power supply device, wherein the CPU turns off the switch means. 9. The CPU according to claim 5, wherein during the battery deterioration determination test, the CPU is the switch.
A DC power supply device characterized in that the switch means is turned off . 10. The DC power supply device according to claim 1, wherein the unidirectional impedance circuit includes a resistor and a diode connected in series. A rectifying device 11. converts AC input power to DC power, and a load circuit connected through via interpolated power supply line of the backflow prevention device to an output of the rectifier device,
Electric power between the backflow prevention element and the load circuit
The backup power supply point of the supply line, each of the scan
A control method of a DC power supply device, comprising: two or more sets of storage batteries connected in parallel to each other , which are connected through an switch element, and which supplies power to the load circuit without interruption. Detect the terminal voltage of the storage battery which is the lowest of those detected voltages and the rectification device
The voltage difference with the output voltage is the magnitude of the terminal voltage of the storage battery.
However, it is possible to reduce charging loss regardless of
A method for controlling a direct-current power supply device , comprising controlling the rectifying device such that the rectifier device is controlled to a predetermined value or less .