JP2001268819A - Power supply unit and feeding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply unit and a feeding method having a simple structure, reducing the amount of generated noise, supplying DC while preventing instantaneous disconnection in the event of power failure in an AC power supply, and supplying DC to a load while preventing excessive current from flowing through the load. SOLUTION: AC voltage supplied from an external AC power supply ACV is rectified by a rectifier RECT1, and a secondary battery B is charged when rectified voltage occurs. The AC voltage supplied by the AC power source ACV is supplied to an electrical apparatus 2. When the AC voltage generated by the AC power supply ACV reach a prescribed lower limit level, a diode D1 is reverse-biased, and the secondary battery B is not discharged. On the other hand, when the AC voltage generated by the AC power supply ACV has not reached the prescribed lower limit level, the diode D1 is forward-biased, and the secondary battery B starts discharging, and the current is supplied to the electrical apparatus 2 through the diode D1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a power supply device and a power supply method, and more particularly to an uninterruptible power supply and an uninterruptible power supply method.

[0002]

2. Description of the Related Art Uninterruptible power supplies that supply power instead of a commercial power supply when a power supply from a commercial power supply or the like is cut off are widely used. An uninterruptible power supply is a rectifier that rectifies AC power supplied from a commercial power supply or the like,
A storage battery that is charged by the current generated by the rectification by the rectifier, a DC-AC converter that converts a DC voltage generated by the storage battery into an AC voltage, and monitors the presence or absence of a power outage. A switch for connecting the converter and the load;

[0003]

However, no power is supplied to the load until a switch connects the DC-AC converter to the load after the power failure is detected, and a so-called instantaneous interruption occurs. . Therefore, the load may not operate normally. In order to shorten the period in which the instantaneous interruption occurs, a method in which the switch is configured by a semiconductor switching element such as a thyristor is considered. However, since a semiconductor switching element such as a thyristor connects a DC-AC converter and a load only when a trigger signal or the like indicating that an instantaneous interruption is detected is supplied, the instantaneous interruption period must be set to zero. Is almost impossible.

[0004] Further, a DC-AC converter generally has a configuration in which a power supply line to which a DC voltage is applied is intermittently connected using a switching element, and thus generates noise. Also, by providing the uninterruptible power supply with a DC-DC voltage,
The configuration of the uninterruptible power supply is complicated and large.

At the moment when the DC-AC converter and the load are connected by the switch, there is a danger that an excessively large current flows from the DC-AC converter to the load.
There is a risk that the load will be destroyed.

The present invention has been made in view of the above circumstances, and provides a power supply apparatus and a power supply method for supplying a direct current without substantially causing an instantaneous interruption when an AC power supply fails. With the goal. Another object of the present invention is to provide a power supply device and a power supply method that have a simple configuration and generate less noise. It is another object of the present invention to provide a power supply device and a power supply method for supplying a direct current when an alternating current power supply is interrupted by preventing a sudden excessive current from flowing to a load.

[0007]

In order to achieve the above object, a power supply device according to a first aspect of the present invention comprises: an AC relay means for supplying an externally supplied AC voltage to an external device; A rectifier that rectifies an AC voltage to generate a rectified voltage; a secondary battery that is charged when the rectifier generates a rectified voltage; and a determination unit that determines whether the AC voltage has reached a predetermined lower limit. And the determining means
And discharging means for supplying a current discharged by the secondary battery to the external device when it is determined that the AC voltage has not reached the lower limit value.

[0008] Such a power supply device supplies a DC voltage generated by a secondary battery to an external device when the AC voltage does not reach the lower limit value (for example, when a power failure occurs). Therefore,
Such a power supply device does not need to include a DC-AC converter serving as a noise generation source, and has a simple configuration.

[0009] The external device may rectify the AC voltage supplied from the AC relay means to generate a rectified voltage. In this case, the determination unit may determine that the direction from the secondary battery to the external device is sequentially between one end of the secondary battery and a node of the external device that is generating the rectified voltage. A rectifying element connected so as to be in the same direction, and the discharging means includes a current path for supplying a current discharged by the secondary battery to the external device via the rectifying element. You may. According to such a power supply device, the discharge of the secondary battery starts immediately as soon as the AC voltage falls below the sum of the voltage between both ends of the secondary battery and the forward voltage of the rectifying element. do not do.

The determination means may include, for example, means for outputting a control signal indicating a result of determining whether or not the AC voltage has reached a predetermined lower limit. In this case, for example, the discharging unit obtains the control signal output by the determining unit, and when the obtained control signal indicates a determination result that the AC voltage has not reached the lower limit value, What is necessary is to form a discharge current path for connecting the secondary battery and the external device to each other, and to substantially cut off a path for supplying the AC voltage to the external device by the AC relay means.

If the discharging current path includes an inductor connected between the secondary battery and the external device, a counter electromotive force generated in the inductor from the moment when the secondary battery starts discharging. The power prevents a sudden and excessive supply of current to an external device.

The AC relay means includes, for example, a primary winding and a secondary winding. When the AC voltage is supplied between both ends of the primary winding, an induced voltage is induced in the secondary winding. And a pair of AC supply current paths for connecting both ends of a secondary winding of the transformer and the external device to each other and bypassing the secondary battery. In this case, the secondary winding of the transformer shall constitute the inductor, and the rectifier rectifies an induced voltage induced in the secondary winding of the transformer to generate a rectified voltage,
The discharging means includes, for example, a first control terminal and a first current path constituting the AC supply current path.
A first switching element for interrupting the first current path in accordance with the control signal supplied to the control terminal of the second control terminal; a second control terminal; and a second current path constituting the discharge current path. A second switching element for interrupting the second current path in accordance with a signal supplied to the second control terminal, wherein the determining means determines that the AC voltage has not reached the lower limit value. When showing the results, the first
A control signal is output to the first control terminal such that the current path is substantially interrupted, and a control signal is output to the second control terminal such that the second current path is substantially conducted. May be provided. Thereby, an abnormal operation such as chattering caused by a mechanical switch is avoided.

The discharging means includes a first control terminal, and a first current path connected between the AC voltage supply source and the external device to constitute the AC relay means. A first switching element for interrupting the first current path according to the control signal supplied to a first control terminal;
A second switching element comprising: a control end of the first current path; and a second current path constituting the discharge current path, wherein the second switching element interrupts the second current path according to a signal supplied to the second control end; Wherein the determining means outputs a control signal such that the first current path is substantially cut off when the AC voltage does not reach the lower limit value. There may be provided a means for outputting to the control terminal, a control signal for outputting the control signal to the second control path such that the second current path is substantially conducted. Again,
An abnormal operation such as chattering caused by a mechanical switch is avoided.

The first switching element is, for example,
A source and a drain forming both ends of the first current path;
The second switching element may include, for example, a source and a drain forming both ends of the second current path, and a first field-effect transistor having a gate that forms the first control terminal. And a second field-effect transistor having a gate that forms the second control terminal.

The rectifier has a common terminal, an input terminal, and an output terminal. The rectifier rectifies the AC voltage applied between the input terminal and the common terminal to provide a rectifier between the output terminal and the common terminal. May generate the rectified voltage. In this case, the AC relay unit includes a pair of power supply lines that connect the common terminal and the input terminal of the rectifier and the external device to each other, and the control unit acquires the control signal acquired by the discharge unit.
When the determination result indicates that the AC voltage has not reached the lower limit value, a discharge current path connecting the secondary battery and the external device to each other via a node including a common terminal of the rectifier is provided. The power supply line that connects the input terminal of the rectifier and the external device to each other may be substantially cut off. This simplifies the configuration of the power supply device as compared to a case where the rectifier includes a pair of input terminals for receiving the supply of the AC voltage and a pair of output terminals for generating the rectified voltage.

Further, a power supply device according to a second aspect of the present invention is an AC relay means for supplying an externally supplied AC voltage to an external device, and rectifies the AC voltage to generate a rectified voltage. A rectifier, a secondary battery charged by a current generated by a rectified voltage generated by the rectifier, and a control signal indicating a determination result by determining whether the AC voltage has reached a predetermined lower limit value. When the control signal output by the external determination device is obtained, and the obtained control signal indicates a determination result indicating that the AC voltage has not reached the lower limit, the secondary battery and the external device are connected to each other. Forming a discharging current path to be connected to supply the current discharged by the secondary battery to the external device, and substantially providing a path for the AC relay means to supply the AC voltage to the external device. Interception Comprising a discharge means for the, characterized in that.

In such a power supply device, when the external determining device determines that the AC voltage does not reach the lower limit value, it supplies the external device with the DC voltage generated by the secondary battery. Therefore, such a power supply device does not need to include a DC-AC converter serving as a noise generation source, and has a simple configuration.

In a power supply method according to a third aspect of the present invention, an AC relay step of supplying an externally supplied AC voltage to an external device, and rectifying the AC voltage to generate a rectified voltage. A rectifying step, a charging step of charging an electric charge when a rectified voltage is generated in the rectifying step, a determining step of determining whether the AC voltage has reached a predetermined lower limit value, and the determining step includes: A discharging step of, when it is determined that the voltage has not reached the lower limit value, supplying a current flowing by discharging the charge charged in the charging step to the external device.

According to such a power supply method, when the AC voltage does not reach the lower limit value (for example, when a power failure occurs), a DC voltage generated by the secondary battery is supplied to an external device.
Therefore, in such a power supply method, there is no need to perform DC-AC conversion for generating noise, and the configuration is simplified.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an embodiment of the present invention will be described below with reference to a DC UPS (Uninterruptible Power).
Supply) will be described as an example.

(First Embodiment) FIG. 1 is a circuit diagram showing a configuration of a DC UPS according to a first embodiment of the present invention. As shown, the DC UPS 1 has a rectifier R
ECT1, a diode D1, a secondary battery B, and a charging control unit CS, and a pair of AC input terminals;
It has a pair of AC output terminals and a DC output terminal comprising a positive electrode and a negative electrode.

The rectifier RECT1 is composed of, for example, a bridge-type rectifier circuit, and has a pair of input terminals and an output terminal composed of a positive electrode and a negative electrode. Rectifier RECT1
Rectifies the AC voltage applied between its own input terminals, and rectifies the rectified voltage obtained by the rectification between both terminals of its own output terminal (however, the positive electrode of the output terminal does not become lower in potential than the negative electrode) So). Each input terminal of the rectifier RECT1 is connected to each AC input terminal of the DC UPS 1 on a one-to-one basis, and connected to each AC output terminal of the DC UPS 1 on a one-to-one basis. The positive terminal of the output terminal of the rectifier RECT1 is
The positive terminal of the DC output terminal of the DC UPS 1 is connected to the positive terminal of a drive terminal in + of the charge control unit CS, which will be described later. The negative terminal of the output terminal of the rectifier RECT1 is connected to the negative terminal of the DC output terminal of the DC UPS 1 and the charge control. Negative electrode in of drive terminal of unit CS
-Connected to

The diode D1 has an anode and a cathode. The anode of the diode D1 is connected to the positive electrode of the secondary battery B, and the cathode is connected to the positive electrode of the DC output terminal of the DC UPS1.

The charge control section CS has a drive terminal and a charge terminal. The drive terminal has a positive electrode in + and a negative electrode in-, and the charge terminal has a positive electrode out + and a negative electrode out-. The positive terminal in + of the drive terminal of the charge control unit CS is
The output terminal of the rectifier RECT1 is connected to the positive terminal, and the negative terminal in- of the drive terminal is connected to the negative terminal of the output terminal of the rectifier RECT1. The positive electrode out + of the charging terminal of the charging control unit CS is connected to the positive electrode of the secondary battery B, and the negative electrode out− of the charging terminal is connected to the negative electrode of the secondary battery B.

The charge control section CS has a positive terminal in +
And negative electrode in− (however, positive electrode in +
Is applied so as to have a higher potential than the negative electrode in-) and the negative terminal ou is driven from the positive terminal out + of the charging terminal.
A current for charging the secondary battery B flows to t−.

The charge control unit CS has a positive terminal out of the charging terminal.
The magnitude of the current flowing from + to the negative electrode out− is controlled so that the secondary battery B is charged under appropriate conditions. In order to determine appropriate conditions for charging the secondary battery B, the charge control unit CS includes, for example, a positive terminal out + and a negative terminal out of a charging terminal.
−, The magnitude of the electromotive force generated by the secondary battery B is detected, and based on the detection result, the current flowing from the pole out + to the negative electrode out− is detected. Determine the size.

The secondary battery B has a positive electrode and a negative electrode, and performs charge and discharge of electric charge. The positive electrode of the secondary battery B is connected to the anode of the diode D1 and the positive electrode out + of the charging terminal of the charging control unit CS as described above, and the negative electrode of the secondary battery B is connected to the negative electrode of the DC output terminal of the DC UPS1, It is connected to the negative terminal out- of the charging terminal of the charging control unit CS. Note that the magnitude of the electromotive force generated by the secondary battery B is a DC
The value is set to be smaller than a value obtained by subtracting the magnitude of the forward voltage of the diode D1 from the expected magnitude of the peak value of the AC voltage to be applied between the AC input terminals of S1.

Next, the operation of the DC UPS 1 for supplying power to the electric equipment 2 to which power is supplied will be described.
However, as shown in FIG. 1, the electric device 2 includes a pair of AC input terminals, a DC input terminal including a positive electrode and a negative electrode, a rectifier RECT2, and a capacitor C1.
Rectifier RECT2 has, for example, substantially the same configuration as rectifier RECT1. Each input terminal of the rectifier RECT2 is connected to each AC input terminal of the electric device 2 on a one-to-one basis. A capacitor C1 is connected between both electrodes of the output terminal of the rectifier RECT2, and a circuit or the like constituting each part of the electric device 2 is connected between both electrodes of the output terminal of the rectifier RECT2. Further, the positive terminal of the output terminal of the rectifier RECT2 is connected to the positive terminal of the DC input terminal of the electric device 2, and the negative terminal of the output terminal of the rectifier RECT2 is connected to the negative terminal of the DC input terminal of the electric device 2.

Then, each AC output terminal of the DC UPS 1 and each AC input terminal of the electric equipment 2 are connected one-to-one, and the DC UP
The positive terminal of the DC output terminal of S1 is connected to the positive terminal of the DC input terminal of the electric device 2, the negative terminal of the DC output terminal of the DC UPS 1 is connected to the negative terminal of the DC input terminal of the electric device 2, and each AC input terminal of the DC UPS1. In the meantime, as shown in FIG. 1, it is assumed that a single-phase AC voltage is applied from an external AC power supply ACV. It is assumed that the magnitude of the peak value of the single-phase AC voltage is equal to or more than the sum of the magnitude of the electromotive force of the secondary battery B and the magnitude of the forward voltage of the diode D1.

Then, the rectifiers RECT1 and RECT2
Each rectifies the single-phase AC voltage applied between the AC input terminals of the DC UPS 1 and generates a rectified voltage between its own output terminals. The rectified voltage generated between the two electrodes at the output terminal of the rectifier RECT2 is smoothed by the capacitor C1, and the rectified voltage of the rectifier RECT2 is smoothed by the capacitor C1.
Each part of the electric device 2 is driven. In addition, rectifier RECT
The rectified voltage generated between the two poles of the output terminal of the first terminal is also the capacitor C
The smoothed rectified voltage of the rectifier RECT1 also contributes to the driving of each unit of the electric device 2.

Further, as a result of the rectifier RECT1 generating a rectified voltage, the positive terminal in + of the drive terminal of the charge control unit CS becomes higher in potential than the negative terminal in-, and the charge control unit CS is driven. Then, the positive terminal out + of the charging terminal of the charging control unit CS
From the above, a current flows through the positive electrode and the negative electrode of the secondary battery B in that order to the negative electrode out− of the charging terminal of the charge control unit CS, and the secondary battery B is charged.

The magnitude of the rectified voltage of the rectifier RECT2 smoothed by the capacitor C1 is equal to the DC UPS
It becomes approximately equal to the peak value of the single-phase AC voltage applied between one AC input terminal. Therefore, when the potential of the negative electrode of the secondary battery B is used as a reference, the voltage at the connection point between the positive electrode of the output terminal of the rectifier RECT2 and the capacitor C1 is higher than the voltage of the positive electrode of the secondary battery B. Therefore, the diode D1 is reverse-biased, and the current path from the connection point between the positive terminal of the output terminal of the rectifier RECT2 and the capacitor C1 to the positive terminal of the secondary battery B is substantially cut off. In addition, there is substantially no path through which the secondary battery B discharges electric charges.

Next, the peak value of the single-phase AC voltage applied between the AC input terminals of the DC UPS 1 is smaller than the sum of the magnitude of the electromotive force of the secondary battery B and the magnitude of the forward voltage of the diode D1. (For example, it is assumed that the single-phase AC voltage is not substantially applied between the AC input terminals of the DC UPS 1).

In this case, the magnitude of the rectified voltage of the rectifier RECT2 smoothed by the capacitor C1 is also smaller than the sum of the magnitude of the electromotive force of the secondary battery B and the magnitude of the forward voltage of the diode D1. Therefore, the connection point between the positive electrode of the output terminal of the rectifier RECT2 and the capacitor C1 has a lower potential than the voltage of the positive electrode of the secondary battery B, and the diode D1 is forward-biased. As a result, a current path is formed from the positive electrode of the secondary battery B to each part of the electric device 2 via the diode D1 and returns to the negative electrode of the secondary battery B, and the secondary battery B discharges.

By repeating the operation described above,
DC UPS1 is used when the peak value of the single-phase AC voltage applied between its own AC input terminals is smaller than the sum of the magnitude of the electromotive force of secondary battery B and the magnitude of the forward voltage of diode D1. , The electric power is supplied from the secondary battery B to the electric device 2.

For example, when the capacitor C1 causes a so-called capacity loss and the smoothing is not substantially performed, the peak value of the single-phase AC voltage applied between the AC input terminals of the DC UPS 1 becomes secondary. Even if it is equal to or greater than the sum of the magnitude of the electromotive force of the battery B and the magnitude of the forward voltage of the diode D1,
In some cases, the voltage of the positive electrode at the output terminal of the rectifier RECT2 is lower than the sum of the magnitude of the electromotive force of the secondary battery B and the magnitude of the forward voltage of the diode D1.

However, also in this case, the diode D 1 is forward-biased, and power is supplied from the secondary battery B to the electric device 2. Therefore, each unit of the electric device 2 receives the supply of power from the DC UPS 1 without being affected by the fact that the capacitor C1 does not perform smoothing. Similarly, when the electric device 2 does not include the capacitor C1, each unit of the electric device 2 supplies the power from the DC UPS 1 without being affected by the absence of the capacitor C1 to be smoothed. receive.

The configuration of the DC UPS 1 is not limited to the above. For example, the DC UPS 1 may have a configuration as shown in FIG. 2, in the DC UPS 1 having the configuration of FIG. 2, the cathode of the diode D1 is connected to the negative electrode of the secondary battery B, and the anode is
It is connected to the negative electrode of the DC output terminal of DC UPS1. The positive electrode of the secondary battery B is not connected to the diode D1, but is connected to the positive electrode of the DC output terminal of the DC UPS1. The negative electrode of the secondary battery B is connected to a rectifier RECT1 or a DC UPS1.
Is not connected to the DC output terminal of The configuration of each of the other parts is substantially the same as the configuration of FIG.

As shown, each pole of the DC output terminal and each AC output terminal of the DC UPS 1 of FIG. 2 have substantially the same connection relationship as that shown in FIG. It is assumed that a single-phase AC voltage is applied from an external AC power supply ACV between the AC input terminals of the DC UPS 1 while being connected to the respective poles of the DC input terminal and the respective AC input terminals. Then, both rectifiers RECT1 and RECT2 rectify the single-phase AC voltage to generate rectified voltages. As a result, the charging control unit CS is driven, and the secondary battery B is charged. Further, each part of the electric device 2 is driven by a voltage obtained by smoothing the rectified voltages generated by the rectifiers RECT1 and RECT2 by the capacitor C1.

When the magnitude of the peak value of the single-phase AC voltage is equal to or more than the sum of the magnitude of the electromotive force of the secondary battery B and the magnitude of the forward voltage of the diode D1, the diode D1 is reverse-biased, and The current path from the negative electrode of the secondary battery B to the connection point between the negative electrode at the output terminal of the rectifier RECT2 and the capacitor C1 is substantially cut off. Accordingly, there is substantially no path through which the secondary battery B discharges electric charges.

Next, it is assumed that the peak value of the single-phase AC voltage applied between the AC input terminals of the DC UPS 1 falls below the sum of the magnitude of the electromotive force of the secondary battery B and the magnitude of the forward voltage of the diode D1. I do. In this case, the diode D1 is forward-biased, a current path is formed from the positive electrode of the secondary battery B, flows through each part of the electric device 2, returns to the negative electrode of the secondary battery B via the diode D1, and the secondary battery B is Perform discharge.

Accordingly, in the DC UPS 1 having the configuration shown in FIG. 2, the peak value of the single-phase AC voltage applied between its own AC input terminals also depends on the magnitude of the electromotive force of the secondary battery B and the forward voltage of the diode D1. When the value becomes smaller than the sum of the values, the power is supplied from the secondary battery B to the electric device 2.

Further, even when the capacitor C1 does not substantially perform smoothing or when the electric device 2 does not include the capacitor C1, the voltage of the positive electrode at the output terminal of the rectifier RECT2 is equal to the electromotive force of the secondary battery B. When the magnitude is smaller than the sum of the magnitude and the magnitude of the forward voltage of the diode D1, the diode D1 is forward-biased. Therefore, power is supplied from the secondary battery B to the electric device 2.

Note that the DC UPS 1 having the configuration shown in FIGS.
May further include a smoothing capacitor connected between both poles of the DC output terminal. Accordingly, when the voltage of the positive electrode at the output terminal of the rectifier RECT2 is smaller than the sum of the magnitude of the electromotive force of the secondary battery B and the magnitude of the forward voltage of the diode D1, the diode D1 is more reliably forward-biased.

(Second Embodiment) FIG. 3 is a circuit diagram showing a configuration of a DC UPS 3 according to a second embodiment of the present invention. As shown, the DC UPS 3 includes a rectifier RECT1, a secondary battery B, a charging control unit CS, a coil L, a power failure monitoring unit REF, and a switching element SWD.
And has a pair of AC input terminals and a power output terminal composed of a positive electrode and a negative electrode. The rectifier RECT1, the secondary battery B, and the charge control unit CS are substantially the same as those in the configuration of FIG. However, in the configuration of FIG. 3, the magnitude of the electromotive force of the secondary battery B may be equal to or smaller than the desired magnitude of the peak value of the target AC voltage applied between the AC input terminals of the DC UPS 3.

Each input terminal of the rectifier RECT1 is connected to a DC UP
Each AC input terminal of S3 is connected one-to-one. The positive terminal of the output terminal of the rectifier RECT1 is connected to the positive terminal in + of the drive terminal of the charge control unit CS, and the negative terminal of the output terminal of the rectifier RECT1 is connected to the negative terminal in− of the drive terminal of the charge control unit CS.
And a terminal b2 of the switching element SWD which will be described later. Positive electrode out of charging terminal of charging control unit CS
+ Is connected to the positive electrode of the secondary battery B. Charge control unit C
The negative electrode out- of the charging terminal of S is the negative electrode of the secondary battery B,
The output terminal of the rectifier RECT1 is connected to the negative electrode and the terminal b2 of the switching element SWD.

The coil L is connected between the positive electrode of the secondary battery B and a later-described terminal a2 of the switching element SWD. The power failure monitoring unit REF includes a comparator and the like, and includes a pair of reference terminals and a control output terminal.
The power failure monitoring unit REF determines whether or not the voltage between its own reference terminals has reached a predetermined lower limit, and outputs a predetermined control signal from its own control output terminal when it determines that the voltage has not reached the lower limit. .

The switching element SWD is composed of, for example, a relay having two circuits and four contacts, and has a control input terminal cont.
And terminals acom, a1, a2, bcom, b1 and b
2 is provided. When the control signal is not supplied to the control input terminal cont of the switching element SWD, the switching element SWD switches between the terminal acom and the terminal a1 and the terminal bc
om and the terminal b1 are made conductive, and between the terminal acom and the terminal a2 and between the terminal bcom and the terminal b2 are cut off. On the other hand, when a control signal is supplied to the control input terminal cont, the terminals acom-a2 and bcom-b2 are made conductive, and the terminals acom-a1 and bcom-b
1 is substantially shut off. The control input terminal cont
And terminals acom, a1, a2, bcom, b1 and b
2 is substantially insulated.

Terminal cont of switching element SWD
Is connected to the control output terminal of the power failure monitoring unit REF.
The terminal acom is connected to the positive terminal of the power output terminal of the DC UPS 3. The terminal bcom is connected to the negative terminal of the power output terminal of the DC UPS 3. The terminals a1 and b1 are connected one-to-one to a pair of AC input terminals of the DC UPS 3. The terminal a2 is connected to the positive electrode of the secondary battery B via the coil L as described above. The terminal b2 is connected to the negative electrode of the output terminal of the rectifier RECT1 and the negative electrode of the secondary battery B as described above.

Next, the operation in which the DC UPS 3 supplies power to the electric equipment 4 having the configuration shown in FIG. 3 will be described. As shown in FIG. 3, the configuration of the electric device 4 is substantially the same as the configuration of the electric device 2 of FIG. However, a pair of ends forming each AC input terminal in the electric device 2 of FIG. 1 form a pair of power input terminals of the electric device 4 in FIG. Further, the electric device 4 in FIG. 4 does not necessarily have a DC input terminal.

As shown, the positive terminal of the power output terminal of the DC UPS 3 is connected to one of the power input terminals of the electric equipment 4, and the negative terminal of the power output terminal of the DC UPS 3 is connected to the electric equipment 4.
It is assumed that a single-phase AC voltage having a peak value equal to or higher than the lower limit value is applied from an external AC power supply ACV between the AC input terminals of the DC UPS 3.
Then, the rectifier RECT1 rectifies the single-phase AC voltage applied between the AC input terminals of the DC UPS 3, and generates a rectified voltage.

At this time, the power failure monitoring unit REF does not supply a control signal. As a result, conduction is established between the terminal acom and the terminal a1 of the switching element SWD, and the terminal bcom
The terminal a1 and the terminal a2 are also substantially electrically disconnected, the terminal acom and the terminal a2 are substantially disconnected, and the terminal bcom and the terminal b2 are also substantially disconnected.

Accordingly, the single-phase AC voltage applied between the AC input terminals of the DC UPS 3 is also applied between the respective power input terminals of the electric device 4. Therefore, the rectifier RECT2
This also rectifies this single-phase AC voltage to generate a rectified voltage. Further, the charging control unit CS is driven by the rectified voltage generated by the rectifier RECT1, and the secondary battery B is charged.
The rectifier REC smoothed by the capacitor C1
Each part of the electric device 4 is driven by the rectified voltage of T2.

Next, it is assumed that the peak value of the single-phase AC voltage applied between the AC input terminals of the DC UPS 3 becomes a value that does not reach the lower limit value. In this case, the power failure monitoring unit REF switches from its own control output terminal to the control input terminal con of the switching element SWD.
Supply a control signal to t. As a result, the terminal acom and the terminal a2 of the switching element SWD conduct, the terminal bcom and the terminal b2 also conduct, the terminal acom and the terminal a1 are substantially cut off, and the terminal bcom and the terminal b2. It is also substantially shut off with b1.

As a result, from the positive electrode of the secondary battery B, the coil L and one of the power input terminals of the electric device 4 flow through each part of the electric device 4, and from the other of the power input terminals of the electric device 4, the secondary battery B A current path returning to the negative electrode is formed, and the secondary battery B discharges. However, at the moment when the discharge is started, a back electromotive force is generated in the coil L in a direction that hinders the supply of current from the secondary battery B to the electric device 4, so that the coil L suddenly flows from the secondary battery B to the electric device 4. As the back electromotive force of the coil L attenuates, the magnitude of the current flowing from the secondary battery B to the electric device 4 increases.

By repeating the operation described above,
The DC UPS 3 supplies power from the secondary battery B to the electric device 4 when the peak value of the single-phase AC voltage applied between its own AC input terminals does not reach the predetermined lower limit.

The configuration of the DC UPS 3 is not limited to the above. For example, the DC UPS 3 may have a configuration as shown in FIG. As shown in the drawing, in the DC UPS 3 having the configuration shown in FIG.
And the terminal b2 of the switching element SWD. The positive electrode of the secondary battery B is not connected to the coil L, and the positive electrode ou of the charging terminal of the charging control unit CS.
t +, the positive terminal of the output terminal of the rectifier RECT1, and the terminal a2 of the switching element SWD. Secondary battery B
Of the rectifier RECT1 and the switching element SW
Not connected to D. The configuration of each of the other units is substantially the same as the configuration of FIG.

As shown, each pole of the power supply output terminal of the DC UPS 3 of FIG. 4 has substantially the same connection relation as the connection relation shown in FIG. In the connected state, it is assumed that a single-phase AC voltage having a peak value equal to or higher than the above-described lower limit is applied between the AC input terminals of the DC UPS 3 from an external AC power supply ACV.

Then, the rectifier RECT1 rectifies the single-phase AC voltage to generate a rectified voltage, so that the charging control unit CS is driven and the secondary battery B is charged. Further, since the power failure monitoring unit REF does not supply the control signal, the single-phase AC voltage applied between the AC input terminals of the DC UPS 3 is also applied between the power input terminals of the electric device 4. Therefore, the rectifier RECT2 also generates a rectified voltage, and each unit of the electric device 4 is driven.

Next, it is assumed that the peak value of the single-phase AC voltage applied between the AC input terminals of the DC UPS 3 in FIG. 4 becomes a value that does not reach the lower limit value. In this case, since the power failure monitoring unit REF supplies a control signal from its own control output terminal, the secondary battery B
A current path flows from the positive electrode to the respective parts of the electric device 4 via one of the power input terminals of the electric device 4 and returns from the other of the power input terminals of the electric device 4 to the negative electrode of the secondary battery B via the coil L. The secondary battery B is formed and discharges. However, since the back electromotive force generated by the coil L from the moment when the discharge is started,
The magnitude of the current flowing from the secondary battery B to the electric device 4 is:
It increases as the back electromotive force of the coil L decreases. Therefore, when the peak value of the single-phase AC voltage applied between its own AC input terminals does not reach the predetermined lower limit, the DC UPS 3 having the configuration of FIG. Power supply.

The rectifier RECT1 is not limited to those shown in FIGS. 1 to 4, but may be, for example, those shown in FIG. The rectifier RECT1 shown in FIG. 5 has an input terminal, a common terminal, and an output terminal, rectifies an AC voltage applied between its own input terminal and the common terminal, and outputs a rectified voltage obtained by rectification to its own output. It occurs between the end and the common end (provided that the output end does not have a lower potential than the common end). The rectifier RECT1 in FIG. 5 may be configured by, for example, a half-wave rectifier circuit.

When the rectifier RECT1 is as shown in FIG. 5, the switching element SWD is connected to the terminals bcom, b1
It is not necessary to provide the control input terminal cont and the terminals acom, a1 and a2 as shown in FIG. And among the parts of DC UPS3,
In the configuration of FIG. 3, a point to be connected to the negative terminal of the output terminal of the rectifier RECT1 is a common terminal of the rectifier RECT1,
It is assumed that the DC UPS 3 is connected to the negative terminal of the power output terminal. In addition, it is assumed that a portion of each unit of the DC UPS 3 that should be connected to the terminal b1 of the switching element SWD in the configuration of FIG. 3 is also connected to the common terminal of the rectifier RECT1.

As shown, each pole of the power supply output terminal of the DC UPS 3 of FIG. 5 has substantially the same connection relation as the connection relation shown in FIG. In the connected state, it is assumed that a single-phase AC voltage having a peak value equal to or higher than the above-described lower limit is applied from an external AC power supply ACV to each AC input terminal of the DC UPS 3 in FIG. Then, this single-phase AC voltage is applied to the input terminal of the rectifier RECT1.
Applied between common ends.

In this case, if the peak value of the single-phase AC voltage applied between the AC input terminals of the DC UPS 3 is equal to or more than the above lower limit, the connection between the terminal acom and the terminal a1 of the switching element SWD is conducted. , The terminal acom and the terminal a2 are substantially shut off. Therefore, the single-phase AC voltage applied between the input terminal and the common terminal of the rectifier RECT1 is applied between the respective power input terminals of the electric device 4.

Next, if the peak value of the single-phase AC voltage applied between the AC input terminals of the DC UPS 3 is a value that does not reach the lower limit value, the terminals acom and a of the switching element SWD are connected.
1 is substantially cut off, and terminals acom and a2
Is substantially conducted. As a result, the current flows from the positive electrode of the secondary battery B to each part of the electrical device 4 via the coil L and one of the power input terminals of the electrical device 4, and from the other of the power input terminals of the electrical device 4 to the negative electrode of the secondary battery B And a current path that returns is formed,
The secondary battery B discharges.

When the rectifier RECT1 has an input terminal, a common terminal, and an output terminal, the rectifier RECT1 converts the rectified voltage obtained by the rectification so that the output terminal does not become higher in potential than the common terminal and outputs its own output. It may occur between the end and the common end. In this case, DC UPS 3 may have the configuration shown in FIG.

That is, as shown in FIG. 6, the switching element SWD does not need to have the terminals acom, a1 and a2, and as shown in FIG.
What is necessary is just to have the terminals bcom, b1 and b2. Then, of the components of the DC UPS 3, in the configuration of FIG. 4, the portion to be connected to the positive terminal of the output terminal of the rectifier RECT1 is connected to the common terminal of the rectifier RECT1 and the positive terminal of the power output terminal of the DC UPS 3. And DC U
In each part of PS3, in the configuration of FIG. 4, a point to be connected to the terminal a1 of the switching element SWD is a rectifier R
It is assumed that it is connected to the common end of ECT1.

As shown, each pole of the power supply output terminal of the DC UPS 3 of FIG. 6 has substantially the same connection relation as the connection relation shown in FIGS. It is assumed that a single-phase AC voltage having a peak value equal to or greater than the above-described lower limit is applied from an external AC power supply ACV to each of the AC input terminals of the DC UPS 3 in FIG.

If the peak value of the single-phase AC voltage applied between the AC input terminals of the DC UPS 3 is equal to or greater than the lower limit, the terminals bcom and b of the switching element SWD
1 and the terminal bcom and the terminal b2 are substantially cut off. Therefore, the single-phase AC voltage applied between the input terminal and the common terminal of the rectifier RECT1 is applied between the respective power input terminals of the electric device 4.

On the other hand, if the peak value of the single-phase AC voltage applied between the AC input terminals of the DC UPS 3 does not reach the lower limit, the terminals bcom and b of the switching element SWD are connected.
1 is substantially cut off, and the terminal bcom and the terminal b2
Is substantially conducted. As a result, the electric power flows from the positive electrode of the secondary battery B to each part of the electric device 4 via one of the power input terminals of the electric device 4, and from the other of the power input terminals of the electric device 4 via the coil L to the negative electrode of the secondary battery B Is formed, and the secondary battery B discharges.

(Third Embodiment) FIG. 7 is a circuit diagram showing a configuration of a DC UPS 5 according to a third embodiment of the present invention. As shown, the DC UPS 5 includes a power failure monitoring unit REF, an inverter INV, a transformer T, a capacitor C2, a secondary battery B, transistors Q1 and Q
2, a resistor R1 to R3, and a diode D2, and has a pair of AC input terminals and a power output terminal including a positive electrode and a negative electrode. The power failure monitoring unit REF
The secondary battery B is substantially the same as the one in the configuration of FIG. 3, and the diode D2 has, for example, the substantially same configuration as the diode D1 in the configuration of FIG. However, the power failure monitoring unit REF outputs a predetermined high-level voltage from its own control output terminal as a component of the control signal. When a control signal is not supplied (that is, when a high-level voltage is not output from the control output terminal), a predetermined low-level voltage is output.

The transformer T has a primary winding and a secondary winding. Both ends of the primary winding of the transformer T are connected one-to-one to the respective AC input terminals of the DC UPS 5. One end of the secondary winding is connected to the positive electrode of the power output terminal of the DC UPS 5, and the other end is connected to the positive electrode of the secondary battery B.

As described above, the positive electrode of the secondary battery B is connected to the other end of the secondary winding of the transformer T that is not connected to the power output terminal of the DC UPS 5, and B
Is connected to a source of the transistor Q2 described later. The capacitor C2 is connected across the secondary winding of the transformer T.

The inverter INV has an input terminal and an output terminal, and generates the above-described high-level voltage at its own output terminal when the above-mentioned low-level voltage is supplied to its own input terminal.
When a high-level voltage is supplied to its own input terminal, a low-level voltage is generated at its own output terminal. Inverter INV
Is connected to the control output terminal of the power failure monitoring unit REF, and the output terminal of the inverter INV is connected to the transistor Q1.
Are connected to a gate described later.

The transistors Q1 and Q2 are
n-channel enhancement type MOSFET (Metal-Ox
ide-Silicon Field Effect Transistor), each having a gate, a source, and a drain. The transistors Q1 and Q2 are turned on when the voltage of each gate is the high-level voltage described above with reference to the potential of each source (that is, each transistor substantially conducts between its drain and source). And Further, when the voltage of each gate is the low-level voltage described above with reference to the potential of each source, the transistors Q1 and Q2 are turned off (that is, the respective drains and sources are substantially cut off). And

The gate of the transistor Q1 is connected to the output terminal of the inverter INV, the source of the transistor Q1 is connected to the negative electrode of the power output terminal of the DC UPS 5, and the drain of the transistor Q1 is connected to the secondary battery B. Is connected to the positive electrode. The gate of the transistor Q2 is
The source of the transistor Q2 is connected to the negative electrode of the secondary battery B, and the drain of the transistor Q2 is connected to the DC UPS5.
Is connected to the negative electrode of the power output terminal of the power supply.

The resistor R1 is connected between the gate of the transistor Q1 and the source of the transistor Q1.
The resistor R2 is connected between the gate of the transistor Q2 and the source of the transistor Q2. Resistor R3
Are cascaded with the diode D2 to form a series circuit. Of the two ends of the series circuit formed by the resistor R3 and the diode D2, the end near the anode of the diode D2 is connected to the negative electrode of the secondary battery B, and the end near the cathode of the diode D2 is DC. It is connected to the positive terminal of the power supply output terminal of UPS5.

Next, the operation in which the DC UPS 5 supplies power to the electric equipment 4 having the configuration shown in FIG. 3 will be described.

As shown in FIG. 7, a positive electrode and a negative electrode of a power output terminal of the DC UPS 5 are connected one-to-one to respective power input terminals of the electric equipment 4, and an external AC is connected between the AC input terminals of the DC UPS 5. It is assumed that a single-phase AC voltage having a peak value equal to or higher than the above lower limit value is applied from the power supply ACV.

Then, the power failure monitoring unit REF receives the gate of the transistor Q2 and the inverter I from its own control output terminal.
A low-level voltage constituting a control signal is supplied to the input terminal of the NV. The inverter INV outputs a high-level voltage from its output terminal to the gate of the transistor Q1 as a result of the low-level voltage being supplied to its own input terminal.

As a result, the transistor Q1 turns on and the transistor Q2 turns off. Then, from the secondary winding of the transformer T, the positive terminal of the power output terminal of the DC UPS 5, the electric device 4, the negative terminal of the power output terminal of the DC UPS 5, the transistor Q
A current path is formed through one source-drain to the secondary winding of the transformer T. Therefore, the AC voltage induced in the secondary winding of the transformer T by the single-phase AC voltage applied across the primary winding of the transformer T via the AC input terminal of the DC UPS 5 Supplied to.

On the other hand, as a result of the AC voltage being induced in the secondary winding of the transformer T, of the two ends of the secondary winding of the transformer T, the end connected to the positive electrode of the secondary battery B is connected. When the potential becomes higher than that at the other end, a current flows from the secondary winding of the transformer T to the secondary winding of the transformer T via the secondary battery B and the diode D2. Therefore, the secondary battery B is charged.

Next, it is assumed that the peak value of the single-phase AC voltage applied between the AC input terminals of the DC UPS 5 becomes a value that does not reach the lower limit value. Then, the power failure monitoring unit REF sends the gate of the transistor Q2 and the inverter I from its own control output terminal.
A high-level voltage is supplied to the input terminal of the NV, and the inverter INV supplies a low-level voltage from its own output terminal to the gate of the transistor Q1.

As a result, the transistor Q2 turns on and the transistor Q1 turns off. Then, in order from the positive electrode of the secondary battery B, the secondary winding of the transformer T, the positive electrode of the power output terminal of the DC UPS 5, the electric device 4, the negative electrode of the power output terminal of the DC UPS 5, and the drain-source of the transistor Q2. Thus, a current path leading to the negative electrode of the secondary battery B is formed. Therefore, the DC voltage generated by the secondary battery B is supplied to the electric device 4. However, at the moment when the secondary battery B starts discharging, a back electromotive force is generated in the secondary winding of the transformer T in a direction that prevents the current supply from the secondary battery B to the electric device 4. Abrupt current rush from the secondary battery B to the electric device 4 does not occur, and the magnitude of the current flowing from the secondary battery B to the electric device 4 increases as the back electromotive force decreases.

By repeating the operation described above,
The DC UPS 5 supplies power from the secondary battery B to the electric device 4 when the peak value of the single-phase AC voltage applied between its own AC input terminals does not reach the predetermined lower limit. On the other hand, when the peak value of the single-phase AC voltage applied between its own AC input terminals has reached a predetermined lower limit, the DC UPS 5 receives the single-phase AC voltage applied between the AC input terminals of the DC UPS 5. A voltage appearing across the secondary winding of the transformer T as a result of the phase alternating voltage being transformed by the transformer T is supplied to the electric device 4.

The configuration of the DC UPS 5 is not limited to the above. For example, the DC UPS 5 may have a configuration as shown in FIG. As shown in FIG. 8, in the DC UPS 5 having the configuration of FIG.
2 is connected to the negative electrode of the power supply output terminal of the DC UPS 5, and the end of the diode D2 close to the cathode is connected to the positive electrode of the secondary battery B. The negative electrode of the secondary battery B is connected to one end of the secondary winding of the transformer T that is not connected to the power output terminal of the DC UPS 5, and the positive electrode of the secondary battery B is It is connected to the drain of transistor Q2. The gate of the transistor Q1 is connected to the output terminal of the inverter INV, and the drain of the transistor Q1 is connected to the DC UPS.
5, and the source of the transistor Q1 is connected to the negative electrode of the secondary battery B.
The gate of the transistor Q2 is connected to the control output terminal of the power failure monitoring unit REF, the drain of the transistor Q2 is connected to the positive electrode of the secondary battery B, and the source of the transistor Q2 is connected to the power output terminal of the DC UPS 5. Is connected to the positive electrode. The configuration of each of the other units is substantially the same as the configuration of FIG.

As shown, each pole of the power supply output terminal of the DC UPS 5 of FIG. 8 has substantially the same connection relation as the connection relation shown in FIG. In the connected state, it is assumed that a single-phase AC voltage having a peak value equal to or greater than the above-described lower limit is applied from an external AC power supply ACV between the AC input terminals of the DC UPS 5.

In this case, since the transistor Q1 is turned on and the transistor Q2 is turned off, the transformer T1 is applied by the single-phase AC voltage applied across the primary winding of the transformer T via the AC input terminal of the DC UPS 5. The AC voltage induced in the secondary winding is supplied to the electric device 4. The transformer T
Of the secondary winding of the transformer T, one end of the secondary winding connected to the negative electrode of the secondary battery B has a lower potential than the other end. , The transformer T
Flows from the secondary winding of the transformer T to the secondary winding of the transformer T via the diode D2 and the secondary battery B, and the secondary battery B is charged.

Next, assuming that the peak value of the single-phase AC voltage applied between the AC input terminals of the DC UPS 5 becomes a value that does not reach the lower limit, in this case, the transistor Q2 is turned on,
The transistor Q1 turns off. Then, from the positive electrode of the secondary battery B to the drain-source of the transistor Q2, the positive electrode of the power output terminal of the DC UPS 5, the electric device 4, the DC UPS
A current path to the negative electrode of the secondary battery B through the negative electrode of the power output terminal 5 and the secondary winding of the transformer T is formed in this order. Therefore, the DC voltage generated by the secondary battery B is supplied to the electric device 4. However, since the back electromotive force is generated in the secondary winding of the transformer T from the moment the secondary battery B starts discharging, the magnitude of the current flowing from the secondary battery B to the electric device 4 is It increases as the power decays.

Accordingly, when the peak value of the single-phase AC voltage applied between its own AC input terminals does not reach the predetermined lower limit, the DC UPS 5 of FIG. Supply power to the On the other hand, when the peak value of the single-phase AC voltage has reached the predetermined lower limit, the DC UP
The voltage appearing across the secondary winding of the transformer T as a result of the single-phase AC voltage applied between the AC input terminals of S5 being transformed by the transformer T is supplied to the electric device 4.

Further, each of transistors Q1 and Q2 may be formed of a p-channel enhancement type MOSFET. Transistors Q1 and Q2 are p
In the case where the DC UPS 5 is configured by a channel enhancement type MOSFET, it is sufficient that the DC UPS 5 has, for example, the configuration illustrated in FIGS. 9 and 10.

In the configuration shown in FIG.
1 is connected to the control output terminal of the power failure monitoring unit REF, and the drain of the transistor Q1 is connected to the DC UPS
5 is connected to the negative electrode of the power supply output terminal, and the source of the transistor Q1 is connected to the positive electrode of the secondary battery B.
The gate of the transistor Q2 is connected to the output terminal of the inverter INV, and the drain of the transistor Q2 is
Connected to the positive electrode of the secondary battery B, the transistor Q2
Is connected to the negative electrode of the power output terminal of the DC UPS 5. The configuration of each of the other units is substantially the same as the configuration of FIG.

In the configuration shown in FIG. 10, the gate of transistor Q1 is connected to the control output terminal of power failure monitoring unit REF, and the source of transistor Q1 is connected to DC UPS.
5, and the drain of the transistor Q1 is connected to the negative electrode of the secondary battery B. The gate of the transistor Q2 is connected to the output terminal of the inverter INV, the source of the transistor Q2 is connected to the positive terminal of the secondary battery B, and the drain of the transistor Q2 is connected to the positive terminal of the power output terminal of the DC UPS 5. It is connected. The configuration of each of the other units is substantially the same as the configuration in FIG.

Then, in the configuration of FIG. 9 and FIG.
The transistors Q1 and Q2 are turned on when the voltage of their respective gates with respect to the potential of their respective sources is a low level voltage, and the voltage of their respective gates with respect to the potential of their respective sources is a high level voltage. It shall be turned off each time.

As shown in FIGS. 9 and 10, each pole at the power output end of the DC UPS 5 having the configuration of FIG. 9 or FIG.
Is connected to each pole of the power input terminal of the electric device 4 so as to take substantially the same connection relationship as shown in FIG. It is assumed that a single-phase AC voltage having a peak value equal to or greater than the lower limit value is applied. In this case, the transistor Q1
Turns on and the transistor Q2 turns off, the transformer T
The AC voltage induced in the secondary winding of the transformer T by this single-phase AC voltage applied across the primary winding is supplied to the electric device 4. Further, as a result of the AC voltage being induced in the secondary winding of the transformer T, the secondary battery B is charged.

On the other hand, if the peak value of the single-phase AC voltage applied between the AC input terminals of the DC UPS 5 becomes a value that does not reach the lower limit, in this case, the transistor Q2 turns on,
Since the transistor Q1 is turned off, the DC voltage generated by the secondary battery B is supplied to the electric device 4. However, due to the back electromotive force generated in the secondary winding of the transformer T from the moment when the secondary battery B starts discharging, the electric equipment 4
The magnitude of the current flowing to increases as the back electromotive force attenuates.

Therefore, the DC UP of the configuration of FIGS.
S5 also supplies power from the secondary battery B to the electric device 4 when the peak value of the single-phase AC voltage applied between its own AC input terminals does not reach the predetermined lower limit. on the other hand,
When the peak value of the single-phase AC voltage has reached the predetermined lower limit, the single-phase AC voltage applied between the AC input terminals of the DC UPS 5 is transformed by the transformer T as a result of the transformer T. The voltage appearing across the secondary winding is supplied to the electric device 4.

Further, DC UPS 5 may have the configuration shown in FIG. The DC UPS 5 having the configuration shown in FIG.
As shown in the drawing, (1) the transistor Q2 is formed of a p-channel enhancement type MOSFET, and (2) the drain of the transistor Q2 is connected to the portion where the source of the transistor Q2 is to be connected in the configuration of FIG. In the configuration of FIG. 7, the source of the transistor Q2 is connected to a point to which the drain of the transistor Q2 is to be connected. (3) The gate of the transistor Q1 is
Instead of being connected to the power failure monitoring unit REF via the inverter INV, it is connected to the gate of the transistor Q2 and (4) is substantially the same as the configuration shown in FIG. 7 except that it does not include the resistor R2. Have the same configuration. However, in the configuration of FIG. 11, the power failure monitoring unit REF outputs a predetermined low level voltage from its own control output terminal as a control signal, and outputs a predetermined high level voltage when the control signal is not supplied. I do.

The DC UPS 5 may have the configuration shown in FIG. The DC UPS 5 having the configuration shown in FIG.
As shown in the figure, (5) the transistor Q2 is formed of an n-channel enhancement type MOSFET, and (6) the drain of the transistor Q2 is connected to the portion where the source of the transistor Q2 is to be connected in the configuration of FIG. In the configuration of FIG. 10, the source of the transistor Q2 is connected to the portion to which the drain of the transistor Q2 is to be connected, and (7) no resistor R2 is provided.
(8) The gate of the transistor Q2 is connected to the inverter IN
It has substantially the same configuration as that shown in FIG. 10 except that it is connected to the gate of the transistor Q1 instead of being connected to the power failure monitoring unit REF via V.

As shown in FIGS. 11 and 12, each pole of the power output terminal of the DC UPS 5 having the configuration of FIG. 11 or FIG.
An external AC power source is connected between the AC input terminals of the DC UPS 5 while being connected to the respective poles of the power input terminal of the electric device 4 so as to have substantially the same connection relationship as that shown in FIG. It is assumed that a single-phase AC voltage having a peak value equal to or higher than the lower limit described above is applied from ACV. In this case, the transistor Q
1 is turned on and the transistor Q2 is turned off, so that the AC voltage induced in the secondary winding of the transformer T by this single-phase AC voltage applied across the primary winding of the transformer T 4. Further, as a result of the AC voltage being induced in the secondary winding of the transformer T, the secondary battery B is charged.

On the other hand, if the peak value of the single-phase AC voltage applied between the AC input terminals of the DC UPS 5 becomes a value that does not reach the lower limit, in this case, the transistor Q2 is turned on,
Since the transistor Q1 is turned off, the DC voltage generated by the secondary battery B is supplied to the electric device 4. However, due to the back electromotive force generated in the secondary winding of the transformer T from the moment when the secondary battery B starts discharging, the electric equipment 4
The magnitude of the current flowing to increases as the back electromotive force attenuates.

Therefore, the DC U of the configuration shown in FIGS.
When the peak value of the single-phase AC voltage applied between its own AC input terminals does not reach the predetermined lower limit value,
The electric power is supplied from the secondary battery B to the electric device 4. On the other hand, when the peak value of the single-phase AC voltage has reached the predetermined lower limit, the transformer T is a result of the single-phase AC voltage applied between the AC input terminals of the DC UPS 5 being transformed by the transformer T. The voltage appearing across the secondary winding of T is supplied to the electric device 4.

7 to 12, of the transistors Q1 and Q2, those formed of an n-channel enhancement type MOSFET are formed of NPN bipolar transistors having a base, an emitter and a collector. It may be replaced by something. Also, a p-channel enhancement type MOSF
The ET may be replaced with a PNP bipolar transistor having a base, an emitter and a collector.

However, in this case, when any of the transistors Q1 and Q2 is composed of a MOSFET, the base, the emitter and the collector are connected to the portion where the gate, source and drain are to be connected. Shall be. When the transistors Q1 and Q2 are composed of NPN-type bipolar transistors, each of the transistors Q1 and Q2 is turned on when the voltage of its own base with respect to the potential of its own emitter is a high level voltage,
It is assumed that each of the bases is turned off when the voltage of its base with respect to the potential of its own emitter is a low level voltage. On the other hand, when the transistors Q1 and Q2 are composed of PNP-type bipolar transistors, each of the transistors Q1 and Q2 is turned on when the voltage of its base with respect to the potential of its own emitter is a low level voltage, and the potential of each emitter is referenced. It is assumed that each of the bases is turned off when the voltage of its own base is a high level voltage.

(Fourth Embodiment) FIG. 13 is a circuit diagram showing a configuration of a DC UPS 6 according to a fourth embodiment of the present invention. As shown, the DC UPS 6 includes a power failure monitoring unit REF, a secondary battery B, transistors Q3 and Q4, resistors R4 to R6, diodes D3 and D4.
And has a pair of AC input terminals and a power output terminal composed of a positive electrode and a negative electrode.

The secondary battery B is substantially the same as that in the configuration of FIG. 3 and includes diodes D3 and D4.
Are the diodes D in the configuration of FIG. 1, for example.
1 has substantially the same configuration. The positive electrode of the secondary battery B is connected to the anode of the diode D3, and the negative electrode of the secondary battery B is connected to the negative electrode of the power output terminal of the DC UPS 6.

Power failure monitoring unit REF in the configuration of FIG.
Is composed of a comparator and the like, and has a pair of reference terminals and a pair of control output terminals outa and outb. The power failure monitoring unit REF determines whether or not the voltage between its own reference terminals has reached a predetermined lower limit. Then, when it is determined that the voltage has reached, the control output terminal outa outputs a high-level voltage as a control signal, and the control output terminal outa
A low level voltage is output from tb. On the other hand, when it is determined that the voltage has not reached, a low level voltage is output from the control output terminal outa, and a high level voltage is output as a control signal from the control output terminal outb.

Each reference end of the power failure monitoring unit REF in FIG.
It is connected one-to-one to the AC input end of DC UPS 6.
The control output terminal outa of the power failure monitoring unit REF is connected to a gate of the transistor Q3, which will be described later. The control output terminal outb of the power failure monitoring unit REF is connected to a gate of the transistor Q4, which will be described later.

The transistors Q3 and Q4 are both
It is composed of an n-channel enhancement type MOSFET and has a gate, a source and a drain, respectively. The gate of the transistor Q3 is connected to the power failure monitor REF
The source of the transistor Q3 is connected to one of the AC input terminals of the DC UPS 6, and the drain of the transistor Q3 is connected to the DC
It is connected to the positive terminal of the power output terminal of PS6. The gate of the transistor Q4 is connected to the control output terminal o of the power failure monitoring unit REF.
utb, the source of the transistor Q4 is connected to the positive electrode of the power output terminal of the DC UPS 6, and the drain of the transistor Q4 is connected to the cathode of the diode D3.

The anode of the diode D4 is connected to the source of the transistor Q4, and the cathode of the diode D4 is connected to the drain of the transistor Q4.

[0111] The resistor R4 is connected between the gate of the transistor Q3 and the source of the transistor Q3.
The resistor R5 is connected between the gate of the transistor Q4 and the source of the transistor Q4. Resistor R6
Is connected between the anode and the cathode of the diode D3 to form a parallel circuit with the diode D3.

As shown in FIG. 13, the power supply output terminal of the DC UPS 6 of FIG. 13 has substantially the same connection relationship as the connection relationship shown in FIG. It is assumed that a single-phase AC voltage having a peak value equal to or greater than the above-described lower limit is applied from an external AC power supply ACV to each AC input terminal of the DC UPS 6 in a state where the single-phase AC voltage is connected to each pole of the input terminal. In this case, since the transistor Q3 is turned on and the transistor Q4 is turned off, the single-phase AC voltage supplied from the AC power supply ACV is supplied to the electric device 4. Also,
During a period in which one end of the AC power supply ACV connected to the transistor Q3 has a higher potential than the other end,
Diode D4 is forward biased. Therefore, a current returns from the AC power supply ACV to the AC power supply ACV through the source-drain of the transistor Q3, the diode D4, the resistor R6, and the battery B in order, and the secondary battery B is charged.

On the other hand, if the peak value of the single-phase AC voltage applied between the AC input terminals of the DC UPS 6 becomes a value that does not reach the lower limit, in this case, the transistor Q4 is turned on,
Since the transistor Q3 is turned off, the DC voltage generated by the secondary battery B is supplied to the electric device 4.

Accordingly, the DC UPS 6 having the configuration shown in FIG.
When the peak value of the single-phase AC voltage applied between its own AC input terminals does not reach the predetermined lower limit, the secondary battery B
To supply electric power to the electric device 4. On the other hand, when the peak value of the single-phase AC voltage has reached the predetermined lower limit,
The single-phase AC voltage applied between the AC input terminals of the DC UPS 6 is supplied to the electric device 4.

The configuration of the DC UPS 6 is not limited to the above. For example, the diode D4 may be configured by a parasitic diode included in the transistor Q4. The transistors Q3 and Q4 both have p
It may be constituted by a channel enhancement type MOSFET. In this case, the DC UPS 6 may have, for example, a configuration as shown in FIG.

In the configuration of FIG. 14, the positive electrode of the secondary battery B is connected to the positive electrode of the power output terminal of the DC UPS 6, and the negative electrode of the secondary battery B is connected to the cathode of the diode D3. Control output terminal out of power failure monitoring unit REF
a is connected to the gate of the transistor Q4, and the control output terminal outb is connected to the gate of the transistor Q3. The drain of the transistor Q3 and the source of the transistor Q4 are both connected to the negative terminal of the power output terminal of the DC UPS 6. The drain of the transistor Q4 is connected to the anode of the diode D3. The anode of the diode D4 is connected to the source of the transistor Q4, and the cathode of the diode D4 is connected to the drain of the transistor Q4. The configuration of the other parts is substantially the same as the configuration of FIG.

As shown in FIG. 14, the power supply output terminal of the DC UPS 6 having the configuration shown in FIG. 14 has substantially the same connection relationship as the connection relationship shown in FIG. Suppose that it is connected to each pole of the input terminal. In this state, if the peak value of the single-phase AC voltage applied between the AC input terminals of the DC UPS 6 from the AC power supply ACV is equal to or greater than the above lower limit, the transistor Q3 is turned on and the transistor Q4 is turned off. Therefore, a single-phase AC voltage supplied by the AC power supply ACV is supplied to the electric device 4. AC power supply AC
During a period in which one end connected to the transistor Q3 is lower in potential than the other end, the diode D
4 is forward biased. For this reason, the AC power supply AV passes through the battery B, the resistor R6, the diode D4, and the drain-source of the transistor Q3 sequentially from the AC power supply ACV.
A current returning to the CV flows, and the secondary battery B is charged. On the other hand, when the peak value of the single-phase AC voltage supplied by the AC power supply ACV does not reach the lower limit, the transistor Q4 is turned on and the transistor Q3 is turned off, so that the DC voltage generated by the secondary battery B is It is supplied to the electric device 4.

Accordingly, the DC UPS 6 having the configuration shown in FIG.
When the peak value of the single-phase AC voltage applied between its own AC input terminals does not reach the predetermined lower limit, the secondary battery B
To supply electric power to the electric device 4. On the other hand, when the peak value of the single-phase AC voltage has reached the predetermined lower limit,
The single-phase AC voltage applied between the AC input terminals of the DC UPS 6 is supplied to the electric device 4.

[0119]

As described above, according to the present invention, a power supply apparatus and a power supply method for supplying a direct current without substantially causing an instantaneous interruption when an AC power supply is interrupted are realized. . Further, according to the present invention, a power supply device and a power supply method that have a simple configuration and generate less noise are realized. Further, according to the present invention, a power supply apparatus and a power supply method for supplying a direct current when an alternating current power supply is stopped by preventing an excessively large current from flowing to a load are realized.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a configuration of a DC UPS according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram showing a configuration of a modification of the DC UPS of FIG. 1;

FIG. 3 is a circuit diagram showing a configuration of a DC UPS according to a second embodiment of the present invention;

FIG. 4 is a circuit diagram showing a configuration of a modification of the DC UPS of FIG. 3;

FIG. 5 is a circuit diagram showing a configuration of a modified example of the DC UPS of FIG. 3;

FIG. 6 is a circuit diagram showing a configuration of a modified example of the DC UPS of FIG. 3;

FIG. 7 is a circuit diagram showing a configuration of a DC UPS according to a third embodiment of the present invention.

FIG. 8 is a circuit diagram showing a configuration of a modification of the DC UPS of FIG. 7;

FIG. 9 is a circuit diagram showing a configuration of a modification of the DC UPS of FIG. 7;

FIG. 10 is a circuit diagram showing a configuration of a modified example of the DC UPS of FIG. 7;

FIG. 11 is a circuit diagram showing a configuration of a modified example of the DC UPS of FIG. 8;

FIG. 12 is a circuit diagram showing a configuration of a modification of the DC UPS of FIG. 9;

FIG. 13 is a circuit diagram showing a configuration of a DC UPS according to a fourth embodiment of the present invention.

FIG. 14 is a circuit diagram showing a configuration of a modified example of the DC UPS of FIG.

[Explanation of symbols]

 1, 3, 5, 6 DC UPS 2, 4 Electric equipment ACV AC power supply B Secondary battery C1, C2 Capacitor CS Charge control unit D1 to D4 Diode INV Inverter L Coil T Transformer Q1 to Q4 Transistor R1 to R6 Resistor RECT1 , RECT2 Rectifier REF Power failure monitoring unit SWD Switching element

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02M 7/08 H02M 7/08 F term (Reference) 5G003 AA01 BA01 DA05 GA01 5G015 FA13 GB02 HA15 JA01 JA05 JA06 JA08 JA11 JA15 JA32 JA55 5H006 CA02 CB03 CC04 CC08 DC05 FA04 5H030 AS03 BB09 BB26 FF41 5H410 BB04 CC02 CC03 CC05 CC09 CC10 DD02 EA11 EA28 EB01 EB37 EB40 FF03 FF22 LL04 LL18

Claims (10)

[Claims] 1. An AC relay means for supplying an externally supplied AC voltage to an external device, a rectifier for rectifying the AC voltage to generate a rectified voltage, and charging when the rectifier generates a rectified voltage. A secondary battery to be determined, determining means for determining whether or not the AC voltage has reached a predetermined lower limit, when the determining means determines that the AC voltage has not reached the lower limit, And a discharging means for supplying a current discharged by the secondary battery to the external device. 2. The external device rectifies an AC voltage supplied from the AC relay unit to generate a rectified voltage. The determination unit includes one end of the secondary battery and the external device. A rectifying element connected between the secondary battery and a node that is generating the rectified voltage so that a direction from the secondary battery toward the external device is a forward direction. The power supply device according to claim 1, further comprising: a current path for supplying a current discharged by the secondary battery to the external device via the rectifying element. 3. The control device according to claim 2, wherein the determining unit outputs a control signal indicating a result of determining whether the AC voltage has reached a predetermined lower limit. The discharging unit outputs the control signal. Acquiring a control signal, and when the acquired control signal indicates a determination result that the AC voltage has not reached the lower limit, a discharge current path connecting the secondary battery and the external device to each other. The power supply device according to claim 1, wherein the power supply device is formed to substantially cut off a path for supplying the AC voltage to the external device by the AC relay unit. 4. The power supply device according to claim 3, wherein the discharge current path includes an inductor connected between the secondary battery and the external device. 5. The AC relay means comprises a primary winding and a secondary winding, and when the AC voltage is supplied between both ends of the primary winding, induces an induced voltage in the secondary winding. A pair of AC supply current paths that connect both ends of the secondary winding of the transformer and the external device to each other bypassing the secondary battery, and The secondary winding constitutes the inductor, the rectifier rectifies an induced voltage induced in the secondary winding of the transformer to generate a rectified voltage, and the discharging unit performs a first control. End and a first line constituting the AC supply current path.
A first switching element for interrupting the first current path according to the control signal supplied to the first control end; a second control end; and the discharging current path. A second switching element configured to interrupt the second current path in accordance with a signal supplied to the second control terminal. Output a control signal such that the first current path is substantially cut off to the first control terminal, when the signal indicates a determination result that the lower limit value has not been reached, and The power supply device according to claim 4, further comprising: means for outputting a control signal to the second control terminal such that a current path is substantially conducted. 6. A first control terminal connected to a first control terminal, a supply source of the AC voltage, and the external device to constitute the AC relay means.
A first switching element for interrupting the first current path according to the control signal supplied to the first control terminal; a second control terminal; and the discharging current path. A second switching element configured to interrupt the second current path in accordance with a signal supplied to the second control terminal. Output a control signal such that the first current path is substantially cut off to the first control terminal, when the signal indicates a determination result that the lower limit value has not been reached, and The power supply device according to claim 3, further comprising: a means for outputting a control signal to the second control terminal such that a current path is substantially conducted. 7. The first switching element according to claim 1, wherein:
Source and drain at both ends of the current path of
A first field-effect transistor having a gate serving as a control terminal of the second current path, wherein the second switching element has a source and a drain forming both ends of the second current path, and the second control terminal. 7. The power supply device according to claim 5, further comprising a second field-effect transistor including: 8. The rectifier has a common terminal, an input terminal, and an output terminal. The rectifier rectifies the AC voltage applied between the input terminal and the common terminal, and connects the output terminal to the common terminal. The AC relay means includes a pair of power supply lines connecting the common terminal and the input terminal of the rectifier and the external device to each other, and the discharging means has acquired the rectified voltage. When the control signal indicates a determination result that the AC voltage has not reached the lower limit value, a discharge that connects the secondary battery and the external device to each other via a node including a common terminal of the rectifier. 5. The power supply device according to claim 3, wherein a power supply line that connects an input terminal of the rectifier and the external device to each other is formed substantially by forming a current path for use. 9. An AC relay means for supplying an externally supplied AC voltage to an external device, a rectifier for rectifying the AC voltage to generate a rectified voltage, and a rectifier voltage generated by the rectifier. A secondary battery that is charged by current, and obtains a control signal output by an external determination device that outputs a control signal indicating a determination result by determining whether the AC voltage has reached a predetermined lower limit value, When the acquired control signal indicates a determination result that the AC voltage has not reached the lower limit, a discharge current path connecting the secondary battery and the external device to each other is formed to form the secondary battery. Discharging means for supplying a current discharged by a battery to the external device, and the AC relay means substantially interrupting a path for supplying the AC voltage to the external device. Do Power supply. 10. An AC relaying step of supplying an externally supplied AC voltage to an external device, a rectifying step of rectifying the AC voltage to generate a rectified voltage, and a rectifying voltage generated in the rectifying step. A charging step of charging the electric charge; a determining step of determining whether the AC voltage has reached a predetermined lower limit; and the determining step determines that the AC voltage has not reached the lower limit. And a discharging step of supplying a current flowing by discharging the charge charged in the charging step to the external device.