KR20080067833A - Uninterruptible power supply system - Google Patents

Abstract

An uninterruptible power supply system is provided to reduce a size of the device by using only one transformer for supplying the power to a load. An interruptible power supply system includes a transformer(21), a rectification circuit(22), a smoothing circuit(23), an output voltage detection circuit(24), a pulse control circuit(25), a driving circuit(26), and first and second power supply lines(27,28). The rectification circuit rectifies a voltage transformed by the transformer. The smoothing circuit smooths the rectified voltage. The output voltage detection circuit detects the smoothed voltage of DC power. The pulse control circuit generates a pulse control signal by comparing the voltage in the output voltage detection circuit and a predetermined reference voltage. The driving circuit generates a driving signal for controlling a switch by using the pulse control signal. The first and second switches are formed in a first power supply line and a second power supply line, respectively, so as to perform switching in correspondence with the driving signal.

Description

Uninterruptible Power Supply {UNINTERRUPTIBLE POWER SUPPLY SYSTEM}

1 is a control circuit block diagram of a conventional uninterruptible power supply.

2 is a control circuit block diagram of an uninterruptible power supply apparatus according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

21: transformer 22: rectifier circuit

23: smoothing circuit 24: output voltage detection circuit

25 pulse control circuit 26 drive circuit

27: first switch 28: second switch

29: first reverse current blocking circuit 30: second reverse current blocking circuit

The present invention relates to an uninterruptible power supply, and more particularly, to an uninterruptible power supply that performs a transformer with two transformers for two power supply lines to achieve a compact size and a reduction in manufacturing cost.

UNINTERRUPTIBLE POWER SUPPLY SYSTEM, as the term implies, refers to a power supply to prevent a system down at the load side in case of an emergency, ie power failure.

As such, the uninterruptible power supply is usefully applied to a large computer room that prevents data loss or a medical system that requires continuous operation even in a power failure.

In general, uninterruption is performed through two completely independent power supply lines, and typical methods include an online method, an offline method, a line interactive method, and the like.

Then, the conventional uninterruptible power supply will be described here.

1 is a control circuit block diagram of a conventional uninterruptible power supply.

As shown in Figure 1, it is composed of a first power supply line and a second power supply line.

The first power supply line includes a first transformer 1 receiving a first power supply and dropping a voltage corresponding to a winding ratio, a first rectifying circuit 2 rectifying the dropped voltage, and smoothing the rectified voltage. A first smoothing circuit (3) to be provided, a first output voltage detecting circuit (4) for detecting the voltage of the DC power supply being smoothed and output, and a pulse wave output from the first output voltage detecting circuit (4). A first pulse control circuit 5 for generating a pulse control signal when it is determined to be a power failure or a low voltage compared with the set reference voltage, and a first drive circuit for generating a drive signal for controlling a switch by the pulse control signal; The furnace 6 and a first switch 7 for switching in response to the drive signal.

In addition, the second power supply line provided to be symmetrical with the first power supply line may include a second transformer 11 receiving a second power supply and dropping the voltage corresponding to the winding ratio, and a second rectifying the dropped voltage. A rectifying circuit 12, a second smoothing circuit 13 for smoothing the rectified voltage, a second output voltage detecting circuit 14 for detecting a voltage of the DC power supply which is smoothed and output, and a second output voltage detecting circuit A second pulse control circuit 15 for generating a pulse control signal when the pulse wave is output from the pulse wave 14 and is determined to be a power failure or a low voltage compared with a preset reference voltage; A second drive circuit 16 for generating a drive signal for controlling and a second switch 17 for switching in response to the drive signal.

As such, the first switch 7 and the second switch 17 are positioned at the front end of the first transformer 1 and the second transformer 11, respectively. Switching to ensure the stability of the power supply.

However, since the power supply circuits having two identical structures are formed, in particular, the bulky transformers 1 and 11 are provided for each power supply line, so that the devices are not only bulky but also have to be configured for each power supply line. There was a disadvantage that the manufacturing cost increases.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, in which two input windings are insulated and connected in parallel so that each power supply line can be transformed in one transformer, thereby making it possible to achieve compactness in manufacturing volume and manufacturing cost. An uninterruptible power supply can be achieved.

One aspect for achieving the above object of the present invention, the first power supply line; A second power supply line; A transformer formed at a constant winding ratio while the input side winding of the first power supply line, the input winding of the second power supply line, and the output side winding are insulated from each other; A rectifier circuit for rectifying the voltage transformed by the transformer; A smoothing circuit for smoothing the rectified voltage; An output voltage detection circuit for detecting a voltage of the smoothed and output DC power supply; A pulse control circuit for generating a pulse control signal by comparing the voltage detected by the output voltage detection circuit with a preset reference voltage; A driving circuit for generating a driving signal for controlling a switch by the pulse control signal; And a first switch formed in the first power supply line and a second switch formed in the second power supply line so as to perform switching in response to the driving signal.

In this case, it is preferable that the apparatus further forms a first reverse current blocking circuit and a second reverse current blocking circuit for blocking a voltage flowing back from the transformer at each front end of the transformer of the first power supply line and the second power supply line. The supply source of the second power supply line may be a battery, and the charging source of the battery may be a first power supply line or a separate power supply line.

Power loads such as servers and medical systems are supplied with power to the first power supply line or the second power supply line through a changeover switch, and the first power supply line is supplied with commercial power for stability and the second power supply. Lines are typically built to be powered from other substations. That is, in a state in which power is supplied from the first power supply line, when the power supplied from the first power supply line is unstable, power is supplied to the power load through the second power supply line after detecting the power supply. Maintain its stability.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

2 is a control circuit block diagram of an uninterruptible power supply apparatus according to an embodiment of the present invention.

As shown in FIG. 2, the transformer 21 is configured to perform a transformer in one transformer 21 for the first power supply line and the second power supply line. In other words, the transformer 21 is composed of two input windings and an output winding which are insulated from each other.

Accordingly, only one rectifier circuit 22 for rectifying the voltage dropped by the transformer 21 and one smoothing circuit 23 for smoothing the rectified voltage are provided.

In addition, the output voltage detection circuit 24 which detects the voltage of the DC power being smoothed and output, compares the voltage detected by the output voltage detection circuit 24 with a preset reference voltage and generates a pulse control signal corresponding thereto. The pulse control circuit 25 and the drive circuit 26 which generate | occur | produce the drive signal for controlling a switch by this pulse control signal also have the structure provided only one by one.

Meanwhile, a first switch 27 is formed in the first power supply line, and a second switch 28 is formed in the second power supply line so as to perform switching in response to the driving signal.

In addition, a first reverse current blocking circuit 29 and a second reverse current blocking circuit 30 for blocking a voltage flowing back from the transformer 21 are respectively provided at the front end of the transformer 21 of the first power supply line and the second power supply line. ) Are formed respectively.

The battery may be used as a power supply source of the second power supply line. The battery may be charged through a separate power supply line, or may be charged through the first power supply line. That is, charging is performed using DC power that is transformed, rectified, and smoothed through the first power supply line, and the inverter circuit (not shown) when power is supplied through the charged battery (second power supply line). You can also use the method of converting the AC power back to the power supply through the power supply).

The uninterruptible power supply device of the present invention configured as described above is supplied with a commercial power supplied from the first power supply line when the device operates normally, and supplies the power to the power load. That is, the commercial power supply is made while the first switch 27 is turned on. At the same time, the second switch 28 is also maintained in an on state. Since the input power is switched to two in this way, the voltage per turn is output by the two voltage dividers. This method can be applied to all circuit methods of the switching power supply circuit.

The transformed voltage is converted into a DC power source through rectification through a diode or bridge diode and smoothing by a capacitor and a resistor. This DC power is supplied to the power load.

On the other hand, the output voltage detection circuit 24 detects the voltage of the DC power supply (output voltage) and compares the reference voltage and the output voltage when the power failure or the reference voltage (set voltage) is lower than the pulse control circuit 25. To feed. In response, the pulse control circuit 25 converts an output pulse corresponding to the output voltage into a frequency or pulse width and outputs the converted pulse. In this case, the pulse width modulation may be achieved through a conventional comparator. In response to the frequency or pulse width signal, the driving circuit 26 outputs a driving signal (switch on / off) to the first switch 27 and the second switch 28. Accordingly, the on / off of the first switch 27 and the second switch 28 is performed to supply power from the first power supply line or the second power supply line.

The present invention is not limited to the above-described embodiments, and it will be apparent that many modifications are possible by those skilled in the art within the technical spirit of the present invention.

As described above, according to the present invention, since a single transformer is used, a circuit configured at the rear of the transformer is also configured with only one circuit (rectifier circuit, smoothing circuit, output voltage detection circuit, pulse control circuit, and driving circuit). In addition, the assembly cost can be reduced and the production cost can be reduced, and since a single transformer is used, it can be usefully applied to mobile equipment by making a compact volume. For example, it can be usefully applied to communication repeaters, backup PCs, medical equipment, and the like.

Claims (4)

A first power supply line; A second power supply line; A transformer formed at a constant winding ratio while the input side winding of the first power supply line, the input winding of the second power supply line, and the output side winding are insulated from each other; A rectifier circuit for rectifying the voltage transformed by the transformer; A smoothing circuit for smoothing the rectified voltage; An output voltage detection circuit for detecting a voltage of the smoothed and output DC power supply; A pulse control circuit for generating a pulse control signal by comparing the voltage detected by the output voltage detection circuit with a preset reference voltage; A driving circuit for generating a driving signal for controlling a switch by the pulse control signal; And A first switch formed in the first power supply line and a second switch formed in the second power supply line so as to perform switching in response to the driving signal; Uninterruptible power supply comprising a. 2. The apparatus of claim 1, further comprising a first reverse current blocking circuit and a second reverse current blocking circuit for respectively blocking a voltage flowing back from the transformer at each of the front ends of the transformers of the first power supply line and the second power supply line. Uninterruptible power supply. 3. The uninterruptible power supply according to claim 1 or 2, wherein a source of the second power supply line is a battery. The uninterruptible power supply of claim 3, wherein the charging source of the battery is a first power supply line or a separate power supply line.

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