JP2697320B2 - Inverter device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter device such as an inverter device in an instantaneous interruption bypass system for supplying power to a computer.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram showing a conventional inverter device. In the drawing, reference numeral 1 denotes an inverter, which receives a DC power from a battery (not shown) to a DC input line 2 and outputs a predetermined frequency and frequency. Voltage, 3 phase in this example, 60 [H
z] and 100 [v] and are supplied to a load such as a computer (not shown) via the output switch 3 and the feeder line 4. Reference numeral 5 denotes a thyristor switch (a so-called bypass switch) serving as an opening / closing means, which is operated to perform a collective opening / closing operation.
The single-pole switches 6, 7 and 8 are provided. Each of the single-pole switches 6 to 8 is configured by connecting thyristors 6a, 6b to 8a, and 8b, whose main circuit electrodes 9 are electronically controlled to open and close, in antiparallel as shown in the figure. 10 is connected to a commercial power supply (not shown) (three-phase, 60 [Hz], 100 [v]),
This is a commercial power supply line that supplies power to the load via the thyristor switch 5 and the power supply line 4. 11 is each thyristor 6a ~
A gate circuit 8b provides a switching signal collectively to the gate 8b, and a synchronization control circuit 12 controls the synchronization between the voltage of the commercial power supply and the output voltage of the inverter 1.

Next, the operation will be described. Normally, the thyristor switch 5 is open, and the inverter 1 supplies AC power to the load via the output switch 3 while being synchronously controlled by the synchronous control circuit 12 with the commercial power supply. When the supply of power is hindered due to a failure of the inverter 1 or the like, the main circuit electrodes 9 of the thyristors 6a to 8b are made conductive by the gate circuit 11 and the thyristor switch 5 is closed. Continue power supply due to momentary interruption. Also, control is performed such that an overcurrent such as an inrush current of a load is automatically switched to a commercial power supply to supply an overcurrent from the commercial power supply at the same time as the occurrence of an overcurrent, and control is switched to the inverter 1 again when the load returns to normal. At this time, since the output voltage of the inverter 1 is controlled so as to synchronize with the commercial power supply, the fluctuation of the supply voltage to the load is prevented.

[0004]

Since the conventional inverter device is constructed as described above, even if the thyristor breaks down while the power is supplied from the inverter 1 and becomes conductive, it cannot be known. There is a problem that the electric potential on the power supply line 10 side and the electric potential on the power supply line 4 side remain in contact with each other. In addition, since the thyristor switch 5 is constituted by a thyristor, it is not possible to visually confirm the opening / closing operation.
It was not possible to check whether the thyristor switch 5 could reliably open and close when needed, while the inverter 1 was operating.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an inverter device which can detect that the electronic switching element of the switching means has failed and is in a conductive state even during the operation of the inverter. Still another object of the present invention is to provide an inverter device capable of confirming the operation of the switching means without disturbing the supply voltage to the load during the operation of the inverter.

[0006]

SUMMARY OF THE INVENTION An inverter device according to the present invention comprises a voltage of an AC power supply capable of supplying power to a load to which power is supplied from the inverter via switching means, an output voltage of the inverter, and a power supply. Controlling the phase difference between the main circuit electrodes of the electronic switching element of the switching means,
The voltage between the main circuit electrodes is detected.
In addition, the switching means is configured so that a single-pole switch having a plurality of poles can be opened and closed at least for each pole, and a single-pole switch of the switching means is controlled by controlling the phase difference between the voltage of the AC power supply and the output voltage of the inverter. And a voltage between the poles of the single-pole switch is detected.

[0007]

When power is supplied from the inverter to the load, the switching means is normally open. In this state, when a voltage is applied between the main circuit electrodes of the electronic switching element by changing the phase difference between the voltage of the AC power supply and the voltage of the inverter, if the electronic switching element fails and becomes conductive, the voltage between the main circuit electrodes is reduced. No voltage is generated, and if the electronic switching element is normal, a voltage is generated between the main circuit electrodes. By detecting this voltage, it is determined whether the electronic switching element has failed and is conducting. be able to. In addition, during the operation of the inverter, the phase difference between the voltage of the AC power supply and the voltage is applied between the poles of each single-pole switch of the switching means, and the single-pole switch of the switching means is opened and closed to open the single-pole switch. The operation of the single-pole switch can be confirmed by detecting the voltage between the poles. In addition, since opening and closing are performed at least for each single-pole switch, a sneak circuit due to opening and closing of the single-pole switch does not occur, and fluctuation of the supply voltage to the load can be prevented.

[0008]

[Embodiment 1] FIG. 1 is a connection diagram showing an embodiment of the present invention. In the figure, reference numeral 21 denotes a transformer as voltage detecting means, and a thyristor 6 connected in anti-parallel is provided.
The primary winding side is connected to each main circuit electrode 9 of the single-pole switch 6 constituted by a and 6b, and detects a voltage between the main circuit electrodes 9 of each thyristor. 22 is a single-phase full-wave rectifier circuit provided on the secondary winding side of the transformer 21, 23 is a reference voltage,
Reference numeral 24 denotes an output voltage of the single-phase full-wave rectifier circuit 22 and a reference voltage 23.
And outputs a voltage when the reference voltage 23 is higher. A frequency meter 25 indicates the frequency of the output voltage of the comparator 24. Although not shown, transformers 21 to 25 are similarly provided between the main circuit electrodes 9 of the single-pole switches 7 and 8.

[0009] Then late with reference to the waveform diagrams of FIGS. 2 to 4
The operation in the failure detection mode will be described. Each thyristor 6
When detecting the faults a to 8b, a higher-level control circuit (not shown) sends a synchronous control circuit 12 as a phase difference control means.
And a control is performed so that the phase difference between the voltage of the commercial power supply and the output voltage of the inverter 1 becomes a predetermined value. As a result, a predetermined voltage is applied between the poles of the thyristor switch 5, that is, between the main circuit electrodes 9 of the thyristors 6a to 8b.

The single-pole switch 6, that is, the thyristor 6a,
When both 6b are normal, the output voltage waveform 31 of the single-phase full-wave rectifier circuit 22 becomes a single-phase full-wave rectified waveform as shown in FIG. The voltage waveform 32 of the reference voltage 23 is shown in FIG.
As shown in (a), it is set to a constant value lower than the peak value of the output voltage waveform 31. The comparator 24 compares the output voltage of the single-phase full-wave rectifier circuit 22 with the reference voltage 23 and outputs a voltage when the reference voltage 23 is higher.
The output waveform 33 has a frequency of 120 as shown in FIG.
[Hz] is output as a pulse, and the frequency meter 25 counts the number of the pulses, and indicates 120 [Hz] as the frequency.

When one of the thyristors 6a and 6b of the single-pole switch 6 fails and is in a conductive state, the output voltage waveform 31 of the single-phase full-wave rectifier circuit 22 and the output waveform 33 of the comparator 24 are shown in FIG. ) And (b), each has a single-phase half-wave rectification and a square wave with a frequency of 60 [Hz], and the frequency meter 25 indicates 60 [Hz].

When both the thyristors 6a and 6b of the single-pole switch 6 fail and are in a conductive state, the output voltage waveform 31 of the single-phase full-wave rectifier circuit 22 and the output waveform 33 of the comparator 24 are shown in FIG. ) And (b), the output voltage waveform 31 outputs zero and the output waveform 33 outputs a constant value.
The frequency meter 25 indicates 0 [Hz].

The same applies to the frequency meters 25 operated by the voltage detected by the transformers 21 (not shown) provided in the other single-pole switches 7 and 8, respectively. It is possible to know whether or not 8c has failed and is in a conductive state.

Embodiment 2 FIG. FIG. 5 is a connection diagram showing another embodiment of the present invention. In the drawing, reference numeral 41 denotes a two-pole thyristor switch constituted by two single-pole switches 6 and 7, each of which is connected to a single gate by a gate circuit 42. Conduction control can be performed independently for each of the thyristors 6 a to 7 b constituting the pole switches 6 and 7. The other configuration is the same as that of the embodiment shown in FIG. 1 except that the power supplied to the commercial power supply line 10 is a single-phase alternating current. .

In one embodiment of FIG. 1, each thyristor 6
Although it has been known whether or not a through 8b have failed and become conductive, in the other embodiment of FIG. 5, the output voltage of the inverter 1 is prevented from being disturbed during the operation of the inverter 1. While the opening / closing operation of the thyristor switch 41 can be confirmed.

Next, the operation in the operation test mode will be described. The thyristor switch 41 is open during normal operation, that is, when the inverter 1 supplies power to the load via the output switch 3 and the power supply line 4.
In this state, the soundness of the operation of the thyristor switch 41 is checked for each of the single-pole switches 6 and 7. An operation test mode signal is given to the synchronous control circuit 12 as the phase difference control means in the same manner as in the failure detection mode in the embodiment of FIG. 1 so that the phase difference between the voltage of the commercial power supply and the output voltage of the inverter 1 becomes a predetermined value. Is controlled so that As a result, a predetermined voltage is applied between the poles of the single-pole switch 6 and the single-pole switch 7 of the thyristor switch 41.

In this case, since the single-pole switches 6 and 7 are both open (non-conducting), the output voltage waveform 31 of the single-phase full-wave rectifier circuit 22 and the output waveform 33 of the comparator 24 are shown in FIGS. In the same manner as shown in b), the frequency meter 25 indicates 120 [Hz].

Subsequently, when only the thyristor 6a is turned on by controlling the gate circuit 42, the single-phase full-wave rectifier circuit 2
2 output voltage waveform 31, comparator 24 output waveform 3
3 is the same as that shown in FIGS. 3 (a) and 3 (b). Since the frequency meter 25 indicates 60 [Hz], the thyristor 6a
Operation can be checked for soundness. Similarly, thyristor 6b,
7a and 7b are individually turned on one by one, and the soundness of the operation is confirmed by checking whether or not the frequency meter 25 indicates 60 [Hz].

In the embodiment shown in FIG. 5, the operation is confirmed in units of the single-pole switches 6 and 7, for example, the thyristors 6a and 6b are simultaneously turned on for the single-pole switch 6, and the output of the single-phase full-wave rectifier circuit 22 is set. The voltage waveform 31 and the output waveform 33 of the comparator 24 are the same as the waveforms shown in FIGS. 4A and 4B, and it may be checked whether or not the frequency meter 25 becomes 0 [Hz]. Further, the thyristor 6a and the thyristor 7a are simultaneously turned on so that the frequency
Can be confirmed by indicating 60 [Hz]. As described above, in the embodiment of FIG. 5, each of the thyristors 6a to 7b or at least the single-pole switch 6,
Since the operation is checked while opening and closing individually every 7 so as to prevent a sneak path from being generated, it is possible to prevent a disturbance from being applied to the output voltage of the inverter 1 during operation.

In each of the embodiments shown in FIGS. 1 and 5, the thyristor switches 5 and 41 are configured by connecting two thyristors in antiparallel to form the single-pole switches 6 and 7, etc. The number of series and parallel elements of the thyristor may be any number. Further, for example, when the single-pole switch 6 is composed of four thyristors in which two thyristors in series are connected in antiparallel, the transformer 21 detects the voltage between the main circuit electrodes 9 of the thyristors in series. As
In the embodiment of FIG. 1, four transformers 21 may be provided for each single-pole switch so that detection can be performed for each element connected in series, or two thyristors connected in series can be collectively detected. You may make it detect.

In the embodiments shown in FIGS. 1 and 5, the frequency meter 25 is used to indicate the frequency of the voltage of the transformer 21, but the output waveform 33 of the comparator 24 is used.
The output waveform 33 may be smoothed through a low-pass filter, paying attention to the fact that changes as shown in FIGS. 2 to 4, and the output waveform 33 may be determined based on the level of this output voltage.
The waveform of the secondary voltage of the transformer 21 may be directly observed with, for example, a CRT oscillograph without providing the transformers 21 to 25. Further, the detection of the voltage between the main circuit electrodes 9 of each thyristor or the like can be performed not by the transformer 21 but by a photointerrupter, an insulating amplifier, a resistive voltage divider or the like, or by directly taking out the voltage.

Of course, the electronic switching element is not limited to a thyristor, but may be a GTO, a transistor, or other electronic switching element.

[0023]

According to the first aspect of the present invention, a voltage is applied between main circuit electrodes of an electronic switching element constituting an opening / closing means by controlling a phase difference of a voltage between an AC power supply and an inverter. Since the voltage between the electrodes is detected, it is possible to know that the electronic switching element has failed and is conducting even during the operation of the inverter.

According to the second aspect of the present invention, the open / close means is configured to open and close a plurality of single-pole switches at least for each pole, and controls a single-phase switch by controlling a phase difference of a voltage between the AC power supply and the inverter. A voltage is applied between the poles of the pole switch to detect the voltage between the poles of the single pole switch, so that the operation of the opening / closing means is checked while preventing the fluctuation of the supply voltage to the load during the operation of the inverter. be able to.

[Brief description of the drawings]

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

FIG. 2 is a waveform diagram illustrating the operation of one embodiment of the present invention.

FIG. 3 is a waveform diagram illustrating the operation of one embodiment of the present invention.

FIG. 4 is a waveform diagram illustrating the operation of one embodiment of the present invention.

FIG. 5 is a connection diagram showing another embodiment of the present invention.

FIG. 6 is a connection diagram showing a conventional inverter device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inverter 4 Power supply line 5 Thyristor switch 6-8 Single pole switch 6a-8b Thyristor 9 Main circuit electrode 10 Commercial power line 12 Synchronous control circuit 21 Transformer 22 Single-phase full-wave rectifier circuit 23 Reference voltage 24 Comparator 25 Frequency meter 41 Thyristor switch 42 Gate circuit

Claims (2)

(57) [Claims] And 1. A inverter supplying power to a load, is constituted by electronic switching element for opening and closing between the main circuit electrode electronically includes a main circuit electrode pair, the inverter
And switching means when the power supply is in an open state to the load from the time of the power non-supplied from the inverter to the load, and the ac power you supply AC power to the load through the switching means, from the inverter While supplying power to the above load
A failure detection mode for inspecting the electronic switching element for failure.
In over de, a phase difference control means for controlling the phase difference between the output voltage and the voltage of the AC power supply of the inverter generates a voltage between the main circuit electrodes of the pair, in the failure detection mode, the 1 and a voltage detecting means for detecting the voltage between the main circuit electrodes pairs, detection by the voltage detecting means in the failure detection mode
Based on the results, it is determined whether the electronic switching element has failed.
An inverter device characterized in that it is turned off . 2. An inverter for supplying electric power to a load, and a plurality of single-pole switches, each of which is constituted by an electronic switching element and can be opened and closed at least individually, are provided .
And switching means from over data when power supply to the load is in an open state, when power is not supplied from the inverter to the load, the AC and power source for supplying power to the load through the switching means, said from the inverter Supply power to the load
Operation test mode for checking the operation of the above single pole switch
In a phase difference control means for generating a voltage between poles of the single-pole switch to control the phase difference between the output voltage and the voltage of the AC power supply of the inverter, in the operation test mode, the single-pole switches and a voltage detecting means for detecting the voltage of the machining gap, among the single-pole switches in the operation test mode
A part of the gap between the electrodes is made conductive, and the voltage detecting means
The operation of the single-pole switch is confirmed based on the detection result.
An inverter device characterized in that: