JPH0441740Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a switching device in an uninterruptible power supply when a switching command is generated when a sequence power supply is lost while power is being supplied from an inverter device.

B. Overview of the invention The present invention uses sequence power loss detection to ensure that switching is performed even when a switching signal is generated at the time of sequence power loss when power is being supplied from an inverter in an uninterruptible power supply. The device is provided with a circuit and a capacitor that discharges a charge according to the output signal of this circuit and uses it as a switching signal.

C. Prior Art Figure 2 shows the configuration of a conventional switching device. When a switching command is output from a control device 4 to an output circuit 5 consisting of a relay, the contacts of the output circuit 5 are closed and an electromagnetic contact is made. A switching signal is output to the device 3. For example, if the electromagnetic contactor 3 is connected to the inverter device 2 side, upon receiving this switching signal, it is switched to the bypass power supply 1 side,
Power is supplied to the load from a bypass power supply 1.

D Problems to be Solved by the Invention In general, the control device 4 is driven by a control power supply 6, and the output signal of the output circuit 5 is supplied by a sequence power supply 7. This is because noise is generated on the power supply side when the contacts of the output circuit 5 operate, and a separate power supply is used to prevent the control device 4 from malfunctioning or malfunctioning due to this noise. .

By the way, in such a device, when power is being supplied from the inverter device 2 side, when an accident occurs in the inverter device 2 and a switching command is output from the control device 4, the sequence power source 7 may be turned off for some reason. If it is lost, even if a switching command is issued and the contact of the output circuit 5 is closed, a switching signal will not be output to the electromagnetic contactor 3, so the contactor 3 will not operate. Therefore, there is a problem that switching from the inverter device 2 to the bypass power supply 1 is not possible.

E Means for solving the problem This invention provides a power loss detection circuit for the sequence power supply in the switching device of the uninterruptible power supply,
The output of this detection circuit is applied to an output circuit to issue a switch turn-on command, and a capacitor that is constantly charged is provided on the sequence power supply side.

F Effect When sequence power is lost, the power loss detection circuit detects this loss and issues a switching command to the output circuit. The output circuit turns on the switch in response to this switching command, discharges the charge stored in the capacitor, and outputs a switching signal to the electromagnetic contactor to switch from the inverter device side to the bypass power source side.

G. Embodiment An embodiment of the present invention will be described below in detail based on FIG. 1. The same reference numerals as in FIG. 2 indicate the same parts.
The explanation will be omitted.

10 is a control device, and this control device 10 includes, in addition to a switching circuit 11 that outputs a switching command based on an external command as in the conventional case, a power loss detection circuit 12 and an OR circuit 13 provided to realize the present invention. have. The power loss detection circuit 12 is connected to the sequence power supply 7.
It constantly monitors the power supply, detects it when power is lost, and outputs an output. C is a capacitor, and this capacitor C is connected to the sequence power supply 7 and is constantly charged. D is a reverse current blocking diode, which is connected in series with the sequence power supply 7 and the switch SW of the output circuit 5, and normally prevents the capacitor C from discharging. Note that the electromagnetic contactor 3 used is of a mechanical latch type.

The operation of the present invention configured as described above will be explained.

During normal operation, the contacts of the electromagnetic contactor 3 are closed between A and B, and the load is connected to the inverter device 2.
It is powered by more power. If an accident occurs in the inverter device 2 during this power supply, the control device 10 detects this and gives a command to the switching circuit 11. Switching circuit 1
1 outputs a switching command to the output circuit 5 via the OR circuit 13 based on this command, closes the switch SW, and issues this switching command to the electromagnetic contactor 3 to the contacts I to C. Thereafter, the load is supplied with power from the bypass power supply 1.

Next, when the load is being supplied with power from the inverter device 2, for some reason the sequence power supply 7
Suppose that the is lost. The power loss detection circuit 12 detects this loss and outputs the power to the output circuit 5 via the OR circuit 13.
and close the switch SW. Therefore, the charge on the capacitor C that is being charged to the polarity shown in the diagram is transferred to the switch SW by closing the switch SW.
It discharges through the SW and issues a switching command to the electromagnetic contactor 3. The electromagnetic contactor 3 switches its contact to the bypass side by the discharge signal of the capacitor C,
It remains latched by the mechanical system.

H. Effects of the Invention According to the present invention, when the sequence power supply is lost, the electromagnetic contactor 3 is immediately switched to the bypass power supply side, so there is no possibility that switching cannot be performed due to the loss of the sequence power supply as in the conventional case.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing one embodiment of the present invention;
The figure is a configuration diagram of a conventional switching device. 10...control device, 11...switching circuit, 12...
...Power loss detection circuit, 13...OR circuit, D...
Backflow blocking diode, C...capacitor.

Claims (1)

[Scope of utility model registration request] In a device that outputs a switching signal to a magnetic contactor via an output circuit connected to a sequence power supply in response to a switching command from a control device connected to a control power supply, and switches the power supply between an inverter device and a bypass power supply. The electromagnetic contactor is of a mechanical latch type, and the sequence power supply is provided with a power loss detection circuit that outputs a switching command to the output circuit when the power supply is lost, and furthermore, a capacitor is provided at the front stage of the output circuit, and a capacitor discharges from the capacitor. What is claimed is: 1. A switching device for an uninterruptible power supply, comprising: a reverse current blocking diode.