JPH10304598A - Power source switching equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power source switching equipment which can surely exhibit hit-free switching function, also when abnormality is generated in feeders between a power source and a load. SOLUTION: Thyristor switches 43A, 43B as main switches are connected with parts between two input terminals 41A, 41B and a common output terminal 42. An (a) contact 44A of an electromagnetic switch is connected in parallel with the thyristor switch 43A. An (a) contact 44B of the other electromagnetic switch is connected in parallel with the thyristor 43B. Thus, a hit-free power source switching circuit is constituted. The thyristor switches 43A, 43B and the electromagnetic switches are controlled by a control part having instantaneous detection function of voltage drop and overcurrent detection function. The power source switching equipment is installed in the vicinity of a load 20. Input terminals 41A, 41B of the equipment are connected with power sources A, B via feeders 30A, 30B. Moreover, when abnormality is generated in the feeders 30A, 30B, hit-free switching of the power source is enabled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply switching device used for supplying power to a load such as a computer without interruption.

[0002]

2. Description of the Related Art Uninterruptible power supplies (10
It is required that an instantaneous voltage drop of msec or less is allowed) and high-quality power is used, and a CVCF device (or UPS) is generally used. In this case, a combination of a single device and a bypass circuit of the commercial power supply, or a parallel redundant system with a bypass circuit, is used to respond to instantaneous voltage drops and overloads (or short-circuit accidents on the load side) by instantaneous switching to improve reliability. May be secured. FIG. 3 shows a configuration example of a parallel redundant system with a bypass circuit.

In FIG. 3, reference numeral 10 denotes a power supply device, and reference numeral 20 denotes a load. The power supply device 10 is a CVCF device 1 connected in parallel.
1-1 to 11-3, commercial power supply bypass circuit 12, CVC
Switching contact 13 of electromagnetic switch for switching between F output and bypass output, thyristor switch 1 for instantaneous interruption switching
4 and the like, and is connected to the load 20 via a feed line 30 for one line.

Usually, CVCF devices 11-1 to 11-3 are used.
Is supplied to the load 20 via the switching contact 13 and the power supply line 30.

When a failure occurs in the power supply device 10 in this operating state, a voltage drop is detected instantaneously, and the thyristor switch 14 is turned on. In other words, the power supply is switched to the commercial power supply bypass circuit 12 without interruption. Subsequently, the switching contact 13 is switched to the bypass circuit 12 side. Thereafter, the bypass output is output via the switching contact 13. During this time, the faulty device is disconnected, and the thyristor switch 14 is turned on and the contact 13 is switched again. As a result, the apparatus is switched to the CVCF apparatus without any interruption.

When an overload occurs, the thyristor switch 14 is turned on in response to the detection of the overcurrent, and the thyristor switch 14 is switched to the commercial power supply bypass circuit 12 without interruption. In this state, the abnormal load is selectively shut off.
Switch to the VCF device side.

[0007]

As described above, the protection operation is quickly performed against a failure or an overload on the power supply device 10 side, and the power supply is supplied to the load 20 without interruption.
Even when the load 20 includes a computer (CPU) that is allowed to have an instantaneous voltage drop of 0 msec or less, the processing operation by the CPU is executed without delay.

However, in a wiring state in which the power supply device 10 and the load 20 which are located far apart from each other, for example, on different floors, are connected by the power supply line 30 for one line, when an abnormality occurs in the power supply line 30 portion. , There is a danger of brownouts or power outages,
The system needs to be reset and restarted.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a power supply switching device capable of properly exhibiting an instantaneous interruption switching function even when an abnormality occurs in a power supply line portion by performing power supply switching near a load. The purpose is to provide.

[0010]

SUMMARY OF THE INVENTION The present invention comprises two inputs individually assigned to two sets of power supplies having the same output conditions;
A common output terminal to which a load is connected, two sets of thyristor switches connected as a main switch between two input terminals and a common output terminal, and an a-contact are connected in parallel to these sets and are energized during overload. A switching circuit constituted by two electromagnetic switches, and a non-instantaneous interruption switching function for turning on the thyristor switch on the standby power supply instantaneously when an instantaneous voltage drop is detected, and then turning off the thyristor switch on the used power supply, And a control unit having an overcurrent protection function for turning off the thyristor switch on the power supply side after energizing the electromagnetic switch on the power supply side upon detecting an overcurrent, and installing the power supply near the load. The power supply can be switched without an instantaneous interruption even when a voltage drop occurs due to an abnormality in wiring between the power supply device installation point and the load installation point.

[0011]

FIG. 1 shows an embodiment of the present invention. In the figure, 20 is a load, 30A and 30B are feeders, 4
0 is a power supply switching device. The power supply switching device 40 includes two input terminals 41A and 41B and a common output terminal 42. The output terminal 42 is connected to the load 20, and one input terminal 41A is connected to one power supply line 30A. Power supply A via
A power source B is individually connected to the other input terminal 41B via one feeder line 30B. Thyristor switches (AC switches) 43A and 43B as main switches are connected between the two input terminals 41A and 41B and the common output terminal 42. Further, a contact 44A of an electromagnetic switch is connected in parallel with the thyristor switch 43A. Is connected in parallel with the thyristor switch 44B to the a contact 44 of another electromagnetic switch.
B are connected to each other to form a switching circuit.
The control section controls the turn-on and turn-off of the thyristor switches 43A and 43B and the opening and closing operations of the electromagnetic switch. The control unit is provided with an instantaneous voltage drop detection function and an overcurrent detection function, and performs instantaneous switching of power supply and overload protection. For the power supplies A and B, a CVCF device (or UPS) or a commercial power supply is used.

Next, the operation will be described. The power supply switching device 40 is installed near the load 20, and power supplies A and B
Are connected via considerably long power supply lines 30A and 30B. Now, it is assumed that power is supplied from the power source A to the load 20. At this time, if a failure occurs on the power supply A side,
A voltage drop is instantaneously detected, and the thyristor switch 43B is turned on within 10 msec or less, and thereafter, the thyristor switch 43a is turned off. That is, the power supply device 10B is switched to the power supply device 10B without any interruption. Such power supply switching without interruption is similarly performed when an abnormality occurs in the power supply line 30A (or 30B).

When an overload occurs, the electromagnetic switch on the side of the used power supply is energized in accordance with the detection of the overcurrent, and
Contact (for example, when power supply A is used, a contact 4
4A) is closed, and the thyristor switch 43A of the main switch is protected from overcurrent.

FIG. 2 shows power supplies 10A and 10B in which power supplies A and B are combined with a CVCF device and a commercial power supply bypass circuit.
This is the case where is used. The power supply device 10A (10B)
VCF device 11A (11B) and commercial power supply bypass circuit 1
2A (12B) are combined, and the switching is performed by a switching circuit 15A (15B).
The switching circuit 15A (15B) has a configuration similar to that of the conventional example (a configuration including a switching contact of an electromagnetic switch, a thyristor switch, and the like).

The operation mode of the instantaneous interruption switching in this case is, for example, the operation of the CVCF device 11A → the failure of the CVCF device 11A → the use of the bypass circuit 12A → the thyristor switch 43B.
The sequence is switched from turn-on to CVCF device 11B operation. With this operation mode, the power supply is automatically switched to a more reliable one without any interruption.

[0016]

As described above, according to the present invention, the instantaneous interruption switching circuit having the overcurrent protection function is installed near the load so that the power supply line to the power supply device is equivalent to two lines. Therefore, in addition to the failure of the power supply unit, it is possible to accurately perform the instantaneous interruption switching not only for the failure of the power supply line between the power supply unit and the load, but also in conjunction with overload protection. Power supply with high quality and high reliability can be expected.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing one embodiment of the present invention.

FIG. 2 is a circuit diagram showing a configuration example of a power supply device to which the present invention is applied.

FIG. 3 is a circuit diagram showing a conventional example.

[Explanation of symbols]

10A, 10B Power supply device 11A, 11B CVCF device 12A, 12B Commercial power supply bypass circuit 15A, 15B Switching circuit 20 Load 30A, 30B Power supply line 40 Power supply switching device 41A, 41B Input terminal 42 Output terminal 43A, 43B: Thyristor switch as main switch 44A, 44B: a contact of electromagnetic switch

Claims (1)

[Claims] 1. A main switch between two input terminals individually assigned to two sets of power supplies having the same output condition, a common output terminal to which a load is connected, and two input terminals and a common output terminal. Two sets of thyristor switches connected to each other and their a contacts are connected in parallel and are energized when overloaded.
A switching circuit composed of a plurality of electromagnetic switches, a thyristor switch on the standby power supply side is instantly turned on when an instantaneous voltage drop is detected, and a non-instantaneous interruption switching function for turning off the thyristor switch on the used power supply side. A control unit having an overcurrent protection function for turning off the thyristor switch on the power supply side after energizing the electromagnetic switch on the power supply side at the time of current detection, and being installed near the load. Power switching device.