JPH0721071Y2 - Uninterruptible power supply output synchronizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to an uninterruptible power supply, which relates to such an uninterruptible power supply and which provides a relatively uniform output waveform to the uninterruptible power supply. In particular, the present invention relates to an uninterruptible power supply output synchronizer in which a commercial power supply waveform before a power failure and an output waveform using a battery as a power source after a power failure are output in synchronization.

(Prior Art) Conventionally, for example, in a system such as a personal computer or an FA device, a power supply such as an abnormal voltage drop caused by an unexpected power outage of a commercial power supply or an unsuitable load on the side of another user during its operation. An uninterruptible power supply is used to deal with an accident, but as shown in FIG. 2, such an uninterruptible power supply 1 normally receives an alternating current input from a commercial power input terminal 2,
Generally, the battery 4 is charged via the charger 3, the direct current thus stored is converted by the inverter 5, and the alternating current is output to the output terminal 7 via the switching means 6.

(Problems to be solved by the invention) However, when a power failure occurs, that is, when the power supply system is switched, the waveform output is not necessarily continuous. The output waveform of the conventional uninterruptible power supply 1 is often as shown in FIG. 4, but the frequency of appearance of such a waveform is 1/2. The above output waveform does not have good continuity between the commercial power supply waveform 8 and the inverter output waveform 9 before the occurrence of a power failure, and when it is remarkable, the phases in the waveform are opposite to each other in this manner. In that case, magnetic saturation occurred when the power supply system was switched, and a large inrush current sometimes flowed to the load. For example, even with a transformer of about 5 A, a rush current of 100 A or more flows, which sometimes has a serious adverse effect on the load.

The present invention has been made to solve the above problems, and an object thereof is to provide an uninterruptible power supply output synchronizer in which the inrush current at the time of switching the power supply system is suppressed to a minimum.

(Means for Solving Problems) In a device that converts the output of a battery by an inverter and outputs it to an alternating current, the positive side is a pulse for reporting the positive side and the negative side of an AC waveform supplied from a commercial power source. Input phase detection circuit that outputs from the reporting terminal and the negative side reporting terminal, an odd number wave that generates a positive side power supply waveform via the inverter when a square wave power source abnormality occurs, and a negative side power supply waveform via the inverter And an even-numbered wave to be divided into two phases, and a waveform divided by the two-phase division circuit is selected by a pulse of the input phase detection circuit immediately before the power supply abnormality, and the commercial power supply waveform and the power supply abnormality are selected. The feature is that the synchronization with the output waveform at the time is brought close.

(Operation) The input position detection circuit detects a pulse waveform for detecting the positive side and the negative side of the commercial power supply until a power failure and outputs it to the two-phase division circuit. The two-phase division circuit divides the square wave output from the square wave generation circuit into an odd-numbered wave and an even-numbered wave by a well-known waveform division method and can output them as drive pulses of an inverter. The inverter is adapted to shift the phase of the waveform to the positive side or the negative side by inputting either the odd-numbered wave or the even-numbered wave. When a power failure occurs, the input position detection circuit outputs the pulse waveform immediately before the power failure to the two-phase division circuit. The two-phase division circuit selects the number wave corresponding to the pulse waveform. The selected number wave is input to the inverter that starts operation due to a power failure. This determines the phase of the first waveform of the inverter. The waveform obtained as described above is shown in FIG. The waveform as shown in the figure suppresses the inrush current to the load to a minimum.

(Embodiment) Next, an uninterruptible power supply output synchronizer according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an example of an uninterruptible power supply output synchronizer of the present invention, in which 11 is an input terminal of an input phase detection circuit, which is indirectly connected to a commercial power output terminal 12. The AC waveform 13 of 100V is normally input here. Reference numeral 14 is an input phase detection circuit, which is formed by, for example, a comparator. This input phase detection circuit 14 outputs respective pulses 17 and 18 for reporting the time of its positive side 15 and negative side 16 of the AC waveform 13 supplied from the commercial power source to the positive side reporting terminal 19 and the negative side reporting terminal 20. . Reference numeral 21 is a square wave generating circuit, which outputs a square wave 22. Reference numeral 23 is a two-phase dividing circuit, which is formed by using, for example, a D flip-flop. This two-phase dividing circuit 23
Divides the inputted square wave 22 into an odd-numbered wave 24 and an even-numbered wave 25, and selectively outputs each of them to the odd-numbered wave output terminal 26 and the even-numbered wave output terminal 27. Output selection is made by pulse 17 and pulse 18 to enable (enable) either the odd-numbered wave output terminal 26 or the even-numbered wave output terminal 27. The waveform thus selected becomes a drive pulse for the switching elements at both ends 28 and 29 of the primary coil of the inverter.

Next, an example of the operation of the uninterruptible power supply output synchronizer of the present invention during a power failure will be described.

When the commercial power supply terminates with a waveform on the negative side such as the waveform 8 in FIG. 3 and a power failure occurs, a pulse 18 is generated from the negative side notification terminal 20 by the input position detection circuit 11 immediately before this power failure ("H Then, it is input to the two-phase division circuit 23. Further, the two-phase division circuit 23 permits the waveform output from the output terminal to the inverter due to a power failure. At this time, the drive pulse to the inverter is the square wave 22 from the square wave generation circuit 21.
Is divided by a two-phase division circuit 23, and an odd number wave 24 is selected. In this way, in the event of a power failure, a synchronized AC output can be obtained from the inverter.

(Effects of the Invention) As described above, the uninterruptible power supply output synchronizer of the present invention is capable of preventing the occurrence of a power failure such as a power failure and switching the power supply.
Since an alternating current with the waveforms of the commercial power supply and the uninterruptible power supply synchronized is output, there is no inrush current from the uninterruptible power supply, and therefore high-quality alternating current that does not adversely affect the load can be supplied. It has a remarkable effect on the industry.

[Brief description of drawings]

1 is a block diagram of an embodiment of the uninterruptible power supply output synchronizer of the present invention, FIG. 2 is a block diagram of an example of a conventional uninterruptible power supply, FIG. 3 is a diagram showing a normal waveform, and FIG. FIG. 6 is a diagram showing an abnormal waveform. In the figure, 14: input phase detection circuit, 21: square wave generation circuit, 23: 2
Phase division circuit.

Claims (1)

[Scope of utility model registration request] 1. A device for converting an output of a battery by an inverter and outputting it to an alternating current, wherein a pulse for reporting a positive side and a negative side of an alternating current waveform supplied from a commercial power source is a positive side reporting terminal and a negative side, respectively. An input phase detection circuit that outputs from the notification terminal, an odd number wave that generates a positive side power supply waveform through the inverter when a square wave is in the power supply abnormality, and an even number wave that generates a negative side power supply waveform through the inverter. And a waveform divided by the two-phase division circuit by the pulse of the input phase detection circuit immediately before the power supply abnormality, and a commercial power supply waveform and an output waveform at the time of power supply abnormality. An uninterruptible power supply output synchronizer characterized by close synchronization of