JP2655151B2 - Uninterruptible power supply synchronizer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an uninterruptible power supply synchronizing apparatus which gives a relatively uniform output waveform to an uninterruptible power supply, and particularly to a commercial uninterruptible power supply before the power outage. The present invention relates to an uninterruptible power supply synchronizer for synchronizing and outputting a power supply waveform and an output waveform using a battery after a power failure as a power supply.

(Prior Art) Conventionally, in a system such as a personal computer and a factory automation (FA) device, a power supply such as an abnormal power failure due to an unexpected power failure of a commercial power supply or an improper load on a customer side during the operation thereof. An uninterruptible power supply is used to cope with the accident. As shown in FIG. 2, such an uninterruptible power supply 1 normally uses the AC input from the commercial power input terminal 2 to charge the charger 3. In general, the DC stored in the battery 4 is converted by the inverter 5, and the AC is output to the output terminal 7 through the switching terminal 6.

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

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and has as its object to provide an uninterruptible power supply synchronizer that suppresses inrush current when switching power supply systems to a minimum.

(Means for Solving the Problems) An uninterruptible power supply synchronizing apparatus according to the present invention is a device for converting an output of a battery by an inverter to output an alternating current, wherein an AC waveform supplied from a commercial power source has a positive side and a negative side. An input phase detection circuit that outputs a pulse for notifying the time of each side from the positive side notification terminal and the negative side notification terminal, and divides a square wave into an odd wave and an even wave and outputs them to the odd wave output terminal and the even wave output terminal A two-phase dividing circuit, and an output for permitting one of the outputs of the two-phase dividing circuit by the output of the input phase detecting circuit and outputting the selected waveform to one of the opposite control input terminals of the inverter. The feature is that it comprises a selection circuit.

(Operation) The square wave output from the square wave generation circuit is divided into odd-numbered waveforms and even-numbered waveforms by a two-phase division circuit, and the divided waveforms are output to separate terminals. On the other hand, when the input phase detection circuit detects the positive side and the negative side of the power supply waveform, it also outputs a pulse waveform to separate terminals. Thus, one of the odd-numbered square wave and the even-numbered square wave is selected by the output selection circuit, and one of them is output to the inverter.This selection is made by the output of the input phase detection circuit, and is obtained as described above. The waveform is shown in FIG. As shown in the figure, in this waveform, the waveform 8 before the power failure and the inverter output waveform 10 have the same phase, and the inrush current is minimized.

Embodiment Next, an uninterruptible power supply 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 synchronizer of the present invention, FIG. 2 is a block diagram of an example of an uninterruptible power supply,
FIG. 3 is a diagram showing a normal waveform, and FIG. 4 is a diagram showing an abnormal waveform. In the figure, reference numeral 11 denotes an input terminal of an input phase detection circuit, which is indirectly connected to a commercial power output terminal 12. It is connected, and an AC waveform 13 of usually 100 V is input here. Reference numeral 14 denotes an input phase detection circuit formed of, for example, a comparator. This input phase detection circuit 14 outputs each pulse 17 and 18 for notifying the time of the positive side 15 and the negative side 16 of the AC waveform 13 supplied from the commercial power supply to the positive side notification terminal 19 and the negative side notification terminal.
Output to 20. Reference numeral 21 denotes a square wave generating circuit which outputs a square wave 22. Reference numeral 23 denotes a two-phase dividing circuit which is formed by using, for example, a D flip-flop. This two-phase dividing circuit 23 converts the input square wave 22 into an odd-numbered waveform 24 and an even-numbered waveform 25.
And output to the odd-numbered waveform output terminal 26 and the even-numbered waveform output terminal 27, respectively. Reference numeral 28 denotes an output selection circuit, which is formed so as to enable either the output terminal 29 or the output terminal 30 by the pulses 17 and 18. The waveform selected in this manner becomes a drive pulse for the switching elements at both ends of the primary coil of the inverter.

Next, an example of the operation of the uninterruptible power supply synchronizing apparatus according to the present invention will be described. When a commercial power supply ends with a negative waveform such as a waveform 8 in FIG. 18 is generated (“H” level), and the odd-numbered waveform output terminal 29 of the output selection circuit 28 is enabled. At this time, a square wave 22 is output from the square wave generation circuit 21. After being divided by the two-phase division circuit 23, the odd wave 24 is output to the output terminal 29 by the above function of the output selection circuit 28. You. The outputted odd-numbered wave 24 becomes a drive pulse for the switching element of the inverter as described above, and thus an AC output synchronized with the inverter is obtained at the time of a power failure.

(Effect of the Invention) As described above, the uninterruptible power supply synchronizer of the present invention
In a device that converts an output of a battery with an inverter and outputs an alternating current, a pulse for reporting a positive side and a negative side of an AC waveform supplied from a commercial power supply is output from a positive side notification terminal and a negative side notification terminal, respectively. An input phase detection circuit, a two-phase division circuit for dividing a square wave into an odd wave and an even wave, and outputting the divided waves to an odd wave output terminal and an even wave output terminal, and the two-phase division circuit based on an output of the input phase detection circuit. An output selection circuit that enables any of the outputs of the inverter and outputs the selected waveform to one of the opposing control input terminals of the inverter. Industrially remarkable effects are obtained such that a high-quality current can be supplied from the device without an inrush current, and thus does not adversely affect the load.

[Brief description of the drawings]

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

Claims (1)

(57) [Claims] In an apparatus for converting an output of a battery by an inverter to output an alternating current, a pulse for reporting a positive side and a negative side of an AC waveform supplied from a commercial power supply is supplied to a positive side reporting terminal and a negative side, respectively. An input phase detection circuit that outputs from the side notification terminal, a two-phase division circuit that divides a square wave into an odd wave and an even wave and outputs the odd wave output terminal and the even wave output terminal, and an output of the input phase detection circuit. An uninterruptible power supply synchronizer, comprising: an output selection circuit that permits any one of the outputs of the two-phase division circuit and outputs the selected waveform to one of the opposite control input terminals of the inverter.