JPH0562159U - Control power supply for uninterruptible power supply - Google Patents

Abstract

(57) [Summary] [Purpose] To reliably detect a rare short circuit of the transformer used for the control power supply of the uninterruptible power supply and prevent the system of the uninterruptible power supply from going down. [Structure] In the control power supply of the uninterruptible power supply, one system is connected from the commercial power supply to the load of the control power supply via the transformer, the rectifier circuit, and the smoothing circuit, and the other system is connected from the output of the uninterruptible power supply itself to the transformer. , A structure in which the smoothing circuit is connected in parallel via a rectifier circuit, a temperature detector is provided in the winding of the transformer, and the output of the temperature detector is connected to the control circuit of the UPS. Is characterized by.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 An uninterruptible power supply (hereinafter abbreviated as UPS) is a device that stably supplies power to a computer, an online system, etc. even if a commercial power supply fails.

In order for the UPS to stably supply power to the load even when a power failure occurs in the commercial power supply, the control power supply of the UPS itself also needs to be uninterrupted.

FIG. 5 is a block diagram showing an example of the structure of the UPS. 1 is a commercial power supply, 2 is an input circuit breaker, 3 is a rectifier circuit, 4 is a battery, 5 is an inverter circuit, and 6 is an output transformer. , 7 is a changeover switch, 8 is an output circuit breaker, 9 is a direct feed circuit, 10 is a load, and 11 is an inverter power transmission circuit. The control power supply requires not only the controller for controlling the entire system shown in FIG. 5 but also an isolated control power supply for driving the power semiconductor used in the inverter circuit.

The present invention is to provide a monitoring circuit in a control power source of a controller or a power semiconductor to improve the stability of the control power source.

[0005]

[Prior Art]

 FIG. 4 shows an example of the configuration of the UPS control power supply. Reference numeral 21 is a commercial power supply, 24 is a UPS output, 22 and 25 are transformers, 23 and 26 are rectifier circuits, 27 is a capacitor, and 28 is a control power supply load. One system is converted from an alternating current to a direct current from a commercial power source 21 via a transformer 22 and a rectifier circuit 23, smoothed by a capacitor 27, and supplied to a load 28 of a control power source. In the other system, the UPS output 24 is converted from AC to DC through a transformer 25 and a rectifier circuit 26, and is connected in parallel with a capacitor 27.

Power is supplied from the commercial power supply 21 to the load 28 when the UPS is started, and power is supplied from the UPS output 24 to the load 28 when the commercial power supply 21 is stopped. The transformers 22 and 25 are necessary to insulate the electric potential of the control power source from the commercial power source 21 and the UPS output 24 and to convert it into the voltage required by the load 28.

When a rare short circuit occurs in the transformer 25 in the circuit shown in FIG. 4, power is not supplied from the UPS to the load 28. However, when the commercial power supply is normal, the UPS is apparently operating normally because the commercial power supply 21 supplies power to the load 28. If a commercial power supply fails in such a state, power is not supplied to the load 28, the control power supply required by the UPS cannot be obtained, and the UPS is in a down state and cannot function as a UPS. Moreover, since a short-circuit current flows through the transformer 25, the transformer 25 is overheated, which may adversely affect other nearby devices and may cause a flame hazard.

Next, when a rare short circuit occurs in the transformer 22, electric power is supplied from the UPS output 24 to the load 28 while the UPS is in operation. However, if the UPS is stopped by periodical inspection or the like, the commercial power source 21 Since it cannot supply power from the load 28 to the load 28, the UPS cannot be started. Further, overheating due to the short circuit current is the same as in the case of the transformer 25.

Generally, a short circuit current of a transformer is generally detected by a thermal overcurrent relay for protection. However, in the case of a small capacity transformer, for example, a transformer of 10 kVA or less, even if a rare short circuit occurs, the short-circuit current is small, so the current for operating the thermal overcurrent relay does not flow, and the rare short circuit occurs. Cannot be detected. In addition, a small-capacity transformer is composed of wires with a small wire diameter, so there is the problem that rare short circuits are likely to occur.

[0010]

[Problems to be solved by the device]

 The present invention is intended to reliably detect a rare short circuit of a transformer used as a control power supply of an uninterruptible power supply and prevent a system down of the uninterruptible power supply.

[0011]

[Means for Solving the Problems]

 The control power supply of the uninterruptible power supply of the present invention is such that one system is connected to the load of the control power supply from the commercial power supply through the transformer, the rectification circuit, and the smoothing circuit, and the other system is connected to the output of the uninterruptible power supply itself. The smoothing circuit is connected in parallel via a transformer and a rectifier circuit, and a temperature detector is provided in the winding of the transformer, and the output of the temperature detector is connected to the control circuit of the uninterruptible power supply. It is characterized by

FIG. 2 is a perspective view of a transformer used as a control power supply of the uninterruptible power supply according to the present invention, and FIG. 3 is a circuit diagram showing its circuit configuration. Reference numeral 31 is an iron core, 32 is a winding wire, and 33 is a temperature detector. The function of the transformer is similar to that of a normal transformer, but the temperature detector 33 is wound in the winding to detect the temperature rise in the winding. By using a thermal fuse or bimetal for the temperature detector, it can be wound in the winding of the transformer.

[0013]

[Action]

 In the transformer having the configuration shown in FIGS. 2 and 3, when a rare short circuit occurs in the winding and a short-circuit current flows through the transformer, the temperature of the winding rises and the temperature detector 33 operates. By connecting the output of the temperature detector 33 to the portion performing the sequence control of UPS, the abnormality of the transformer can be detected.

When an abnormality is detected, the risk of an accident such as a power failure of the control power supply can be minimized by taking measures such as promptly replacing it with a normal transformer, and overheating of other nearby equipment. The adverse effects of and the danger of burning can be minimized.

[0015]

【Example】

 FIG. 1 shows a block diagram of a control power supply of an uninterruptible power supply device according to the present invention constructed by using the transformer shown in FIGS. The basic configuration is the same as that of the control power supply shown in FIG. 4, except that the transformers 41 and 42 shown in FIGS. 2 and 3 are used, and the outputs of the temperature detectors of the transformers 41 and 42 are different. It is connected to the sequence circuit 43. When an abnormality occurs in the transformers 41, 42, the abnormality indicator 44 can identify the abnormality and the location of the abnormality.

If an abnormality of the transformer 41 or 42 is displayed on the abnormality indicator 44, the abnormality can be promptly changed to a maintainable state according to the UPS system configuration (parallel redundant system, direct transmission without instantaneous interruption switching system, etc.). Replace the generated transformer. For example, in the UPS of the direct delivery non-interruption switching system shown in FIG. 5, power is supplied to the load by the direct delivery circuit 9, the inverter power transmission circuit 11 is stopped, and the transformer is replaced.

[0017]

[Effect of the device]

 Like the control power supply of the uninterruptible power supply according to the present invention, a transformer in which a temperature detector is wound around the winding is used, and the output of the temperature detector is connected to the UPS sequence control circuit to display an error indication. Even if a rare short circuit occurs in the control power supply transformer that is supplied with parallel power from the commercial power supply and the UPS output by control, the control power supply supplies an apparently normal voltage to the load. Therefore, the abnormality of the transformer of the control power supply, which was not recognized due to a rare short circuit, causes the system down of the UPS caused by the power failure of the control power supply due to the power failure of the commercial power supply, and the failure of re-output after the UPS is stopped due to the periodic inspection etc. It was previously possible to detect. Moreover, if an abnormality is detected, the transformer can be replaced promptly to minimize the adverse effects on the adjacent equipment due to overheating of the transformer and the risk of flame.

[Brief description of drawings]

FIG. 1 is a block diagram of a configuration example of a control power supply of an uninterruptible power supply according to the present invention.

FIG. 2 is a perspective view of an example of a transformer including a temperature detector in a winding used for a control power supply of an uninterruptible power supply according to the present invention.

FIG. 3 is a connection diagram of the transformer shown in FIG.

FIG. 4 is a block diagram showing an example of a control power supply of a conventional uninterruptible power supply.

FIG. 5 is a block diagram of a configuration example of a conventional uninterruptible power supply system.

[Explanation of symbols]

 1 Commercial power supply 2 Input breaker 3 Rectifier circuit 4 Battery 5 Inverter circuit 6 Output transformer 7 Changeover switch 8 Output breaker 9 Direct transfer circuit 10 Load 11 Inverter transmission circuit 21 Commercial power supply 22, 25 Transformer 23, 26 Rectifier circuit 24 Uninterruptible Power supply output 27 Capacitor 28 Control power load 31 Iron core 32 Winding 33 Temperature detector 43 Sequence circuit 44 Abnormality indicator

Claims (1)

[Scope of utility model registration request] 1. In a control power supply for an uninterruptible power supply, 1
The system was connected from the commercial power source to the load of the control power source via the transformer, the rectifier circuit and the smoothing circuit, and the other system was connected in parallel to the smoothing circuit from the output of the uninterruptible power supply itself via the transformer and the rectifier circuit. A control power supply for an uninterruptible power supply, characterized in that a temperature detector is provided in a winding of the transformer, and an output of the temperature detector is connected to a control circuit of the uninterruptible power supply.