JPS62104435A - Non-interruption electric source - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an uninterruptible power supply.

B8 Summary of the Invention The present invention provides an uninterruptible power supply that supplies power from a battery in place of the AC w source during a power outage, in which the DC output of a forward converter is boosted to a predetermined voltage and reversed. In addition to being input to the converter, the DC output of the forward converter is boosted to a voltage lower than the DC input voltage of this inverse converter and is supplied to the battery, and when the AC power supply is normal, the boosted output of the forward converter is reverse converted. By configuring the battery to supply power to the load, and in the event of a power outage of the AC power source, the charging power of the battery is reversely converted to supply power to the load, a dedicated battery charging device is not required, and a single device is used. The input power factor has been improved by a total of 9, and the capacity of the open-side transformer can be reduced.

C0 Prior Art Conventional uninterruptible power supplies employ a DC switch type and a floating charging type. A DC switch-type uninterruptible power supply device converts the AC output of the AC power supply into DC power using a forward converter when the AC power supply is normal, supplies the DC power to the load via an inverse converter, and converts the AC output of the AC power supply into DC power via a reverse converter. The battery is charged by a charger that converts the output forward, and when the AC power supply fails, the DC input of the inverse converter is switched to the battery side by a DC switch to supply power to the load. In addition, floating charging method uninterrupted t1! The L source device connects in parallel a battery and an inverter that inversely converts DC power to the output side of a forward converter whose output voltage can be adjusted and supplies AC power to the load. The converter is phase-controlled to supply desired DC power to the inverter while charging the battery, and when the AC power supply is interrupted, the charging power of the battery is inversely converted to complete the supply.

D0 Problems to be Solved by the Invention The above-mentioned uninterruptible power supply device using the DC switch method has the disadvantage that a dedicated charging device for the battery is required, which increases the size of the device. Further, a control device is required to switch the DC switch in the event of a power outage of the AC power source, resulting in problems such as the overall configuration of the device being extremely complicated.

The above-described floating charging type uninterruptible power supply device has a drawback of poor input power factor because the phase of the forward converter is controlled. For this reason, there were problems such as the need to increase the capacity of the transformer provided on the input side of the forward converter.

The present invention was developed in view of the above points, and eliminates the need for a dedicated battery charger and DC switch, reduces the capacity of the transformer, and eliminates fluctuations in the output voltage during power outages and power restorations. The purpose is to provide an uninterruptible power supply device that can supply power without interruption.

Means for Solving the E0 Problem The present invention comprises a forward converter that connects diodes in a bridge to convert all AC power from a commercial power supply into direct current power, and boosts the DC output of this forward converter to a predetermined voltage. a first chopper circuit that boosts the DC output of the forward converter to a voltage lower than the output voltage of the first chopper circuit; a battery; a diode having an anode connected to the battery and a cathode connected to a DC input terminal of an inverter; and a diode for inverting the DC output of the first chopper circuit when the commercial power supply is normal.

The present invention is characterized by comprising an inverter that inversely converts the DC output of the battery and supplies it to the load during a power outage of the power source.

20 Functions In the device configured as described above, when the commercial power supply is normal, the DC output of the first chopper circuit is inversely converted to supply power to the load, and during a power outage, the load is charged by the DC output of the second chopper circuit. The charged battery power is reversely converted and power is supplied to the load. In this way, the first. A second chopper circuit is provided to boost the DC output of the forward converter, eliminating the need for phase control of the forward converter, improving the input power factor of the device, and reducing the capacity of the input-side transformer. . Also, 1st. By controlling the second chopper circuit, the DC input voltage of the inverter can be kept higher than the charging voltage of the battery, so that there is almost no fluctuation in the output voltage at the time of power failure or power restoration.

G. Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, reference numeral 1 denotes a forward converter for converting alternating current (CMC) power introduced from a commercial power source (not shown), and is constructed by, for example, connecting all diodes in a bridge. The positive output end of the forward converter 1 is connected to the inverse converter 4 via the DC reactor 2a and the anode and cathode of the diode 3a, and is connected to the battery 5 via the DC reactor 2b and the anode and cathode of the diode 3b. is connected to the positive terminal of the A first chopper circuit 7a that boosts the DC power to a predetermined voltage is connected to a common connection point 6 between the DC reactor 2& and the diode 3a. A second chopper circuit 7b that boosts the DC power to a voltage lower than the output voltage of the first chopper circuit 7 is connected to a common connection point 8 between the DC reactor 2b and the diode 3b. A common connection point 9 between the diode 3b and the battery 5 is connected to an anode of a diode 3c, and a cathode of the diode 3c is connected to the inverter 4. The voltage on the cathode side of the diode 3c is input to the first matching circuit 101L.

The first matching circuit 1.0a matches the set voltage vSl of the first reference voltage setter 111L and the cathode side voltage of the diode 3C, and sends the deviation output to the first automatic voltage adjustment circuit 12a. do. The first automatic voltage adjustment circuit 12 & controls all switching of the first chopper circuit 7a so that the deviation output of the first matching circuit 10 & becomes zero. As a result, the voltage on the cathode side of the diode 3c (DC input side of the inverter 4) is kept constant at the set voltage VS1. The voltage on the anode side of the diode 3c is applied to the second matching circuit 1. It is input to Ob. A second matching circuit 10b matches the set voltage vS of the second reference voltage setter 11b and the anode side voltage of the diode 3c, and sends the deviation output to the second automatic voltage adjustment circuit 12b. do. This second automatic voltage adjustment circuit 12b controls the switching of the chopper circuit 7b of WJ2 so that the deviation output of the second matching circuit 10b becomes zero. As a result, the anode side voltage of the diode 3c (terminal voltage of the battery 5) is kept constant at the set voltage vS. The AC output side of the inverter 4 is connected to a load 13.

Next, the operation of the nine devices constructed as described above will be described. First, when the commercial power supply (not shown) is normal, the output voltage of the forward converter 1 is boosted by the first chopper circuit 7a, and is supplied to the inverse converter 4 via the diode 3IL. At this time, the DC input voltage of the inverter 4 and the first reference voltage setting device 11
The first automatic voltage adjustment circuit 12 & controls the switching of the first chopper circuit 7ai so that the deviation output of & becomes zero.

As a result, the DC input voltage of the inverter 4 is kept constant at the set voltage vS of the first reference voltage setter 11 &, and stable AC power is supplied to the load 13. Further, when the commercial power supply (not shown) is normal, the output voltage of the forward converter 1 is boosted by the second chopper circuit 7b, and the output voltage of the forward converter 1 is boosted by the second chopper circuit 7b.
(supplied to the battery 5 via r. At this time, the charging pressure of the battery 5 and the second reference voltage setting device 11
The second automatic voltage adjustment circuit 12b performs switching control of the second chopper circuit 7bf so that the deviation output of the second chopper circuit 7bf becomes zero. As a result, the pressure of 911t of battery 5 is
The set voltage VS.

The set voltage V of the second reference voltage setter 11b is lower than
S, is kept constant. Next, if the commercial power supply (not shown) is out of power, 1. Second chopper circuit 7&.

7b is stopped, and the charging voltage of battery 5 is supplied to inverter 4 via diode 3c.

At this time, the inverter 4 connects the battery 5 to the diode 3C.
The DC power led through the converter is reversely converted to supply power to the load 13.

As mentioned above, in the event of a power outage, the output of the forward converter 1 is converted to DC power boosted by the first chopper circuit 7a, and the battery 5
Since the inverter 4 is driven by the photoelectric energy of , stable alternating current 1 can be supplied to the full load 13 without being affected by power outages. Furthermore, when the power is restored, the DC output of the forward converter 1 is boosted by controlling the switching of the first chopper circuit 7a, and the DC power is then transferred to the inverse converter 4.
is supplied to Also, the voltage on the DC input side of the inverter 4 (cathode side of the diode 3c) is 1! of the total battery δ! Since the voltage is also controlled to a high level (VSl>VSz), there is almost no voltage fluctuation during a power outage or power restoration, and stable power can be supplied to the load. Furthermore, since the forward converter 1 does not perform phase control, the capacity of the transformer on the commercial side can be reduced.

E Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) Since a forward converter whose phase cannot be controlled is used, and the DC output of the forward converter is boosted by the first and second chopper circuits, the input power factor of the device is improved, making it possible to improve the input power factor of the device. The capacitance of the DC switch can be reduced, and an inexpensive diode can be used in place of the DC switch.

(2) First. By controlling the second chopper circuit, the input voltage of the inverter can be kept high as well as the charging voltage of the battery, so the operation of the diode in item (1) above allows the output to be output during a power outage or when power is restored. Voltage fluctuations are almost eliminated.

(3) There is no need to provide a dedicated battery charger and a DC switch to switch to the battery side in the event of a power outage.

[Brief explanation of drawings]

The drawing is a circuit diagram showing an embodiment of the present invention. 1... Forward converter, 4... Inverse converter, 5... Batch y-17h, 7b... Chopper circuit, ioa, 1. O
b... Matching circuit, lla, llb... Reference voltage setter, 12a. 12 b... Automatic voltage adjustment circuit, 13... Load.

Claims (1)

[Claims] A forward converter formed by bridge-connecting diodes and converting AC power from a commercial power source into DC power; a first chopper circuit that boosts the DC output of the forward converter to a predetermined voltage; and a DC output of the forward converter. a second chopper circuit that boosts the voltage to a voltage lower than the output voltage of the first chopper circuit; a battery that is charged by the DC output of the second chopper circuit; A diode connected to the DC input terminal of
The device is characterized by comprising an inverter that inversely converts the DC output of the first chopper circuit when the commercial power supply is normal, and inversely converts the DC output of the battery and supplies it to the load when the power supply is out of power. Uninterruptible power supply.