JP4151242B2 - Commercial power latch system for uninterruptible power supply system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a commercial power supply latch device for a continuous commercial power supply type uninterruptible power supply that can continue the supply or interruption of power from a commercial power supply to a load even when a control power supply fails.
[0002]
[Prior art]
FIG. 4 is a circuit diagram showing a first conventional example of a continuous commercial power supply uninterruptible power supply. This first conventional circuit has a configuration in which a normally closed contact 2 is inserted between a parallel connection circuit of a load 10 and a backup power supply 9 and a commercial power supply 1 and this normally closed contact 2 is driven by a control power supply 8. However, the control power supply 8 is a power supply that supplies operation power to various control circuits provided in the uninterruptible power supply. In the always commercial power supply type uninterruptible power supply apparatus shown in the first conventional circuit of FIG. 4, AC power is supplied from the commercial power source 1 to the load 10 via the normally closed contact 2 that is closed. The backup power source 9 is composed of, for example, a combination of a power converter and a battery. Normally, the battery is charged with AC power from the commercial power source 1. If the commercial power source 1 fails, the power stored in the battery is stored. To the load 10. At this time, the control power supply 8 issues an opening command to the normally closed contact 2 to open it, thereby preventing the power from the backup power supply 9 from flowing back to the commercial power supply 1.
[0003]
In addition, even when the commercial power source 1 is operating normally, if the supply of AC power from the commercial power source 1 to the load 10 is to be stopped, the normally closed contact 2 is opened by giving a drive command to the control power source 8. .
FIG. 5 is a circuit diagram showing a second conventional example of a commercial power supply type uninterruptible power supply. This second conventional circuit is configured such that a normally open contact 3 is inserted between a parallel connection circuit of a load 10 and a backup power supply 9 and a commercial power supply 1 and the normally open contact 3 is driven by a control power supply 8. However, the control power supply 8 supplies the operating power to the various control circuits provided in the uninterruptible power supply device in the same manner as in the first prior art circuit described above. In the continuous commercial power supply type uninterruptible power supply device shown in the circuit of the second conventional example of FIG. 5, a drive command is given to the control power supply 8 to close the normally open contact 3, and AC power from the commercial power supply 1 is supplied to the load 10. Supply.
[0004]
[Problems to be solved by the invention]
In the first prior art circuit of FIG. 4 described above, for example, when the commercial power source 1 fails and the backup power source 9 supplies power to the load 10, the normally closed contact 2 must be opened. When 8 fails, power for keeping the normally closed contact 2 open is lost, so that the normally closed contact 2 is in a closed state. Alternatively, the normally closed contact 2 is closed when the control power supply 8 fails even though the normally closed contact 2 is opened to cut off the power from the commercial power supply 1 to the load 10. 1 and the load 10 are connected.
[0005]
In the second conventional circuit shown in FIG. 5, if the control power supply 8 fails while the commercial power supply 1 is supplying AC power to the load 10, the normally open contact 3 loses its operating power and opens. That is, although the commercial power source 1 is normal, the power supply to the load 10 is interrupted and a power failure state occurs.
Therefore, an object of the present invention is to maintain the state before and after the failure of the control power supply, even when the control power supply fails in the open / closed state of the contact inserted between the commercial power supply and the load and driven by the control power supply. Is to make it.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the commercial power supply latch device of the continuous commercial power supply type uninterruptible power supply device of the present invention comprises:
A first contact that is normally closed and driven by a control power source that supplies control power to the uninterruptible power supply is connected in series with a second contact that is normally open of the electromagnetic relay to form a series contact circuit.
Insert this series contact circuit between the commercial power supply and the parallel connection circuit of the load and backup power supply,
When the output of the control power supply is zero, the load side of the series contact circuit is selected, but when driven by the control power supply, the switching contact for selecting the commercial power supply side of the series contact circuit;
A series connection circuit of a diode and a capacitor inserted between the switching contact and the other end of the commercial power supply,
A coil of the electromagnetic relay is connected in parallel to the capacitor.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a circuit diagram showing an embodiment of the present invention. In this embodiment circuit, the first contact 12 that is driven by the control power supply 18 to open the circuit, but is closed when the output of the control power supply 18 is zero, and the second contact 13 that is normally opened to the electromagnetic relay are provided. A series contact circuit 11 is configured by connecting in series, and this is inserted between the commercial power supply 1 and the load 10. A backup power supply 9 is connected to the load 10 in parallel.
[0008]
A switching contact 14 capable of selecting either of them is connected to both ends of the series contact circuit 11, and the other end of the series contact circuit 11 is connected to the commercial power supply 1 via a series circuit of a diode 15 and a capacitor 17. Is connected to one end. The switching contact 14 selects the commercial power supply 1 side of the series contact circuit 11 when driven by the output of the control power supply 18, but the load 10 side of the series contact circuit 11 when the output of the control power supply 18 is zero. Operate to select. The coil 16 of the electromagnetic relay provided with the second contact 13 is connected to the capacitor 17 in parallel.
[0009]
FIG. 2 is a circuit diagram showing the state where the AC output of the commercial power supply is cut off in the embodiment circuit shown in FIG. 1, and the control power supply 18 drives the first contact 12 to open it. However, since the output from the control power supply 18 to the switching contact 14 is zero, the switching contact 14 selects the load 10 side as shown. Therefore, the coil 16 is not excited and the second contact 13 is open.
[0010]
Therefore, when the control power supply 18 fails and its output becomes zero in the state of FIG. 2, the first contact 12 is simply switched to the closed state, and the switching contact 14 does not move, so the second contact 13 Maintain the same state. That is, even if the control power supply 18 breaks down when the output of the commercial power supply 1 is cut off, the output of the commercial power supply 1 is kept cut off.
[0011]
FIG. 3 is a circuit diagram showing a state in which the AC output of the commercial power supply is supplied to the load in the embodiment circuit shown in FIG. 1. In this case, the output of the control power supply 18 is zero and the first contact 12 is shown. Since the control power source 18 drives the switching contact 14 to switch to the commercial power source 1 side of the series contact circuit 11, the path of the commercial power source 1 → the switching contact 14 → the diode 15 → the capacitor 17 → the commercial power source 1 The current flows to excite the coil 16 and close the second contact 13. Therefore, AC power from the commercial power source 1 is applied to the load 10.
[0012]
When the connection between the commercial power source 1 and the load 10 is completed, a command is given to the control power source 18 and the switching contact 14 is switched from the load 10 side to the commercial power source 1 side. Therefore, the second contact 13 is kept closed.
Even if the control power supply 18 breaks down and the output becomes zero in this state, the first contact 12 continues to be closed, and the switching contact 14 also remains in the state where the contact is on the load 10 side. The AC power from the power source 1 continues to be supplied to the load 10.
[0013]
【The invention's effect】
In the conventional commercial power supply type uninterruptible power supply, the contact inserted between the commercial power supply and the load is driven by the control power supply, so the connection state between the commercial power supply and the load is normal. There was a problem that it was different from when the control power supply failed. On the other hand, in the present invention, even if the control power source fails while the commercial power source is supplying AC power to the load, the commercial power source can continue to supply AC power as it is. On the contrary, the output of the commercial power source is cut off. In this case, even if the control power supply fails, the AC output of the commercial power supply continues to be cut off, so that the commercial power supply can be latched.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing an embodiment of the present invention. FIG. 2 is a circuit diagram showing a state where an AC output of a commercial power supply is cut off in the embodiment circuit shown in FIG. Fig. 4 is a circuit diagram showing a state in which an AC output of a commercial power supply is supplied to a load in the embodiment circuit shown in Fig. 4 Fig. 4 is a circuit diagram showing a first conventional example of an uninterruptible power supply system with constant commercial power supply 5] Circuit diagram showing a second conventional example of a continuous commercial power supply uninterruptible power supply [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Commercial power supply 2 Normally closed contact 3 Normally open contact 8, 18 Control power supply 9 Backup power supply 10 Load 11 Series contact circuit 12 First contact 13 always closed Second contact 14 normally opened 14 Switching contact 16 Coil

Claims (1)

A first contact that is normally closed and driven by a control power source that supplies control power to the uninterruptible power supply is connected in series with a second contact that is normally open of the electromagnetic relay to form a series contact circuit.
Insert this series contact circuit between the commercial power supply and the parallel connection circuit of the load and backup power supply,
When the output of the control power supply is zero, the load side of the series contact circuit is selected, but when driven by the control power supply, the switching contact for selecting the commercial power supply side of the series contact circuit;
A series connection circuit of a diode and a capacitor inserted between the switching contact and the other end of the commercial power supply,
A commercial power supply latch device for a continuous commercial power supply uninterruptible power supply, wherein the coil of the electromagnetic relay is connected in parallel to the capacitor.

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