JPH051963Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a switching circuit that switches power supply to a load to a bypass side when an inverter device or the like of an uninterruptible power supply device fails.

B. Overview of the invention This invention applies a bypass switching command to an electromagnetic switching device by energizing a relay, and switches the power supply to a load from an inverter device to a bypass power supply. While connected to the control power supply, by connecting the relay contact to the bypass power supply and obtaining a bypass switching command, even if the control power supply or sequence power supply is lost, the load is reliably transferred to the bypass power supply side. be.

C. Prior Art An example of the circuit configuration of an uninterruptible power supply is shown in FIG. 2. In Fig. 2, 1 is an inverter device that converts DC to AC, 2 is an AC filter that shapes the output of the inverter 1 into a sine wave, and 3 is an electromagnetic switch that switches between the bypass power supply and the output of the AC filter 2. , 4 is a control device equipped with a failure detection function for the inverter device 1, and 5 is a bypass switching command generation unit which connects a transistor 5A to a control power source via a coil of a relay 5B, and connects a relay contact to a sequence power source. A bypass switching command is given to the electromagnetic switching device 3 when the circuit is closed.

With such a configuration, if a failure occurs in the inverter device 1 while in the inverter power supply state, this will be detected by the control device 4, and the bypass switching command generation section 5 will operate to switch the electromagnetic switching device 3. be exposed. That is, power is supplied to the load from the bypass power supply.

D Problems to be solved by the invention However, when the bypass switching command is issued from the control device 4, if the sequence power supply has already been lost,
The switching command will not be transmitted, and the electromagnetic switching device 3 will not operate. This is because the sequence power source and the control power source are generally separate from each other due to noise concerns.

E Means for Solving Problems The present invention connects a capacitor in parallel to the relay and switching element of the bypass switching command generating section, such as a series circuit of transistors, and when the control power supply fails, the charge in the capacitor is transferred to the relay. A diode is connected between the capacitor and the control power source so that the current flows to the switching element, and the relay contact is connected to the bypass power source.

F Effect The voltage of the control power supply is applied to the capacitor of the command generation section via the diode, and charging is performed. If a failure occurs in this state, the transistor is turned on, the relay is energized, and a command is given to the electromagnetic switch. As a result, the switching device operates and power is supplied to the load from the bypass power supply side. Even if the control power source or sequence power source is lost, the command is reliably output as the capacitor charging voltage becomes the relay drive voltage, and switching is performed reliably.

G Example Figure 1 shows an example of the present invention.
12 is a control device equipped with a failure detection function, and 12 is a bypass switching command generation unit. This command generation unit 12
is a transistor 12A that is turned off when a failure is detected in the control device 11, a transistor 12B as a switching element that is turned off when this transistor 12A is turned on, and a relay coil that is connected to this transistor 1.
2B, a diode 12D connected between the coil of the relay 12C and the control power source, and a diode 12D connected in parallel to the series circuit of the relay coil and transistor 12B, and charged by the control power source via the diode 12D. capacitor 1
2E, a resistor 12F connected between the cathode of the diode 12D and the collector of the transistor 12A, and a Zener diode 12G connected between the collector of the transistor 12A and the base of the transistor 12B. The contacts of the relay 12C are connected to a bypass power source, and when the contact is closed, a bypass switching command is given to an electromagnetic switch (see FIG. 2).

Next, the operation will be described. If a failure occurs in the inverter device (see FIG. 2) or the like, it is detected by the failure detection function of the control device 11. Upon this failure detection, the transistor 12A of the command generation section 12
is turned off, and transistor 12B is turned on. That is, relay 12C is activated. This relay 12
C is energized by the control device 11 when control power is lost.
Since the output of is also lost, transistor 12A is turned off and transistor 12B is turned on, which is caused by the charge on capacitor 12E. When the relay contact is closed, the voltage of the bypass power supply is applied to the electromagnetic switching device via this contact, and the power supply to the load is switched from the inverter device to the bypass power supply.

H. Effects of the invention As described above, according to the invention, the bypass switching command generating section (switcher driving section) is provided with a capacitor that is normally charged and serves as a power source in the event of a failure, while a relay contact is provided. By connecting to the bypass power supply and giving the bypass switching command to the electromagnetic switching device, even if the control power supply or sequence power supply is lost in the event of a failure, the switching command can be given to the electromagnetic switching device, ensuring that the load is It becomes possible to move to the bypass power supply side.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of a bypass switching circuit of an uninterruptible power supply according to the present invention, and FIG. 2 is a circuit diagram showing a conventional example. 11...control device, 12...bypass switching command generation section, 12A and 12B...transistor,
12C...Relay, 12D...Diode, 12
E...Capacitor, 12F...Resistor, 12G...
Zener diode.

Claims (1)

[Claims for Utility Model Registration] An electromagnetic switching device that switches power supply to a load from an inverter device to a bypass power source, a control device that is connected to a control power source and that detects a failure of the inverter device and outputs a detection signal, and A bypass switching command generating section is provided, which includes a switching element that is turned on by a signal, a relay connected in series to this switching element, and a relay contact that outputs a bypass switching command to the electromagnetic switching device when the relay is energized. In a bypass switching circuit for an uninterruptible power supply, a capacitor is connected in parallel to the series circuit of the relay and the switching element, and the capacitor is connected in parallel to the series circuit of the relay and the switching element so that the charge in the capacitor flows to the relay and the switching element in the event of a failure of the control power supply. In addition to connecting a diode between the capacitor and the control power source, the relay contact is connected to the bypass power source as a circuit configuration in which the switching element is made conductive by the control device output when the control power source is lost, and the bypass power source is given a bypass switching command. A bypass switching circuit for an uninterruptible power supply, characterized in that the power source is