JPS59194673A - power supply - Google Patents

Abstract

PURPOSE:To reduce the variation in the current of an inverter of operative side in two stages and to decrease the variation in the load voltage by interrupting all switching elements of a defective inverter by a defect signal for the prescribed period, and interrupting an AC switch after the prescribed period. CONSTITUTION:If an inverter 1-1 becomes defective, defect detecting means in a device 5-1 detects it, and first forcibly interrupts the switching element connected to all arms of the inverter 1-1. Then, an AC switch 2-1 is opened after several cycles of the responding time of a normal inverter voltage control system by switch OFF signal generating means disposed in the device 5-1, and disconnects the defective inverter 1 from the output bus.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power supply device used in an uninterruptible power supply device, etc., in which a plurality of AC power supplies including inverters are connected in parallel.

The configuration of a prior art device of this type will be explained with reference to FIG. 1-1.1-2 is an inverter, and its switching elements include, for example, a reverse-blocking three-terminal thyristor with a forced extinguishing auxiliary thyristor, a transistor, and a gate Kuhn-off thyristor. 2-1.2-2 is an AC switch, for example, a semiconductor switching element such as a transistor, a thyristor, or a transistor, or a mechanical switch such as a contactor is conveniently used. 3-1.3-2 is a series reactor, and 4-1.4-2 is a parallel capacitor, each of which constitutes a filter. 5-1 and 5-2 are devices for detecting failures in the inverters 1-1 and 1-2 and disconnecting the AC switches 2-1 and 2-2, and 10 is a load. From the fault detection device/fuku 5-1.5-2 to the inverter i-
There is no control signal path shown by a dotted line connecting i, 1-2 in the prior art.

FIG. 2 is a diagram showing electric sewing of the required part of the power supply on one side of FIG. 1, and FIG. 3.4 is a vector diagram.

Next, the operation of the prior art shown in FIG. 1 will be explained using FIGS. 2 to 4. In Fig. 2, vI is the output voltage of the inverter,
■□ is the current flowing before the filters 3 and 4, that is, the inverter output sleep current. Vx is the voltage drop of the series reactor 3, Io is the current flowing to the capacitor 4, vL is the load wake-up pressure, and ■ is the shared load current. In Figure 1, 2
When two inverters 1 and 1-2 are operated in parallel and load 10 is 100% load, the vector diagram when each inverter shares 50% of the load current I'fc is shown in Figure 3. It becomes like this. The absolute value of the load voltage vL is IV Ll = 1.0, the absolute value of the load voltage is l'Ll = o, 5 load power ratio = o, 7, t flowing to capacitor 4, I C/7) The absolute value is II cl =
0.3, the absolute value of the inverter output current ■1 is I
I11=0.37. At this time, since the inverter is controlled so that its output VL is constant, the series reactor 3 is considered to be almost only the reactance.
If the impedance is 0.28 degrees, the inverter output DC current ■ and the direct pressure drop V in the series reactor 3 will be delayed by 90 degrees with respect to the inverter output DC current 11, resulting in the vector ■ in Figure 3. .

The absolute one shift is IVXI=lI Ilx o, 2=o, o 74.

In this situation, if one inverter-1 fails for some reason, the device t5-1 detects this failure and switches the AC switch 2-1 to disconnect the output from the parallel bus.
When cut, the vector diagram on the healthy side becomes as shown in Figure 4. @ In Figure 4, vector vL" I= ■I is the condition before the failure, that is, the same load voltage, inverter output DC, and inverter output voltage as in Figure 3. AC switch 2 on the faulty machine side -1 is cut off, the output current of the inverter 2-2 on the healthy side changes from the load current ■1, which had been shared by the four deceased devices, to 11 and becomes II.

In other words, the output current of the healthy inverter 1-2 suddenly changes to 11. At the same time, the load voltage suddenly changes from vL to vLl because there is an actance drop Vx1. Therefore, the magnitude of the output voltage v'ivL suddenly changes by about 10% to IV L,l.

As described above, the conventional technology has the disadvantage that when one inverter is disconnected due to acid 1, the DC flowing to the healthy inverter operated in parallel changes suddenly, resulting in a large change in the load voltage. was there.

This invention eliminates the drawbacks of the prior art described above, and even if one inverter operating in parallel fails and is disconnected,
The purpose of this is to prevent fluctuations in the voltage supplied to the load from becoming large, and its configuration includes means for extinguishing all switching elements of a failed inverter for a predetermined period of time in response to a signal from a means for detecting a failure of the inverter, and a means for extinguishing all switching elements of the failed inverter for a predetermined period of time by a signal from a means for detecting a failure of the inverter. It is characterized by having a means for later viewing the AC switch.

An example of this hilarious example will be explained below. Figure 5.6 is a vector diagram illustrating the operation of Jin's light.

Assume that one of the inverters 2-1 in FIG. 1 has failed as described above. At this point, the fault 1 extraction means located inside the device 5-1 in FIG.
-1 switching elements connected to all arms! I
jlJ a cut. At this time, the ° control wholesale signal meridian is the first
Indicated by the dotted line in the figure. Next, the switch-on signal generation means in the device 5-1 causes the AC switch 2 to turn on after a cycle which is the response time of the Torihama inverter compression suppression system 1.
-1 and disconnect the faulty inverter 1-1 from the output bus.

This operation sequence will be explained with reference to FIGS. 5 and 6. Figure $5 is a vector diagram when all arms of the faulty inverter 1-1 are cut off by J, and in the figure, VL.

It, , and VI are the load voltage, load current, and inverter output current, respectively, in FIG.

In this case, the inverter 1-1 will be disconnected from the output bus, but the filters 3, 4 on the failed inverter 1-1 side. The AC switch is in the subsequent state, and in particular, the parallel capacitor 4-1 becomes a load for the healthy inverter 1-2. Therefore, inverter 1 on the healthy side
The output DC of 2 is obtained by adding IC and IL to II.
becomes. At this point, the load voltage is increased and the actance drop V is determined, vLX! It changes from to vLl, but its absolute value is IV, ,
l = about 0.98, and the change ridge is small.

The inverter 1-1 maintains its output voltage vLI at a constant level after each cycle due to its output constant voltage control system. vL,
The goods are controlled so that l = lvLl.

After this output voltage transient fluctuation is stabilized, that is, after a predetermined period of time, the AC switch 2-1 is turned off, and the inverter 1-1 and filter 3-1.4-1 are disconnected from the output bus. A vector diagram at this time is shown in FIG.

4. The output current of the inverter 1-2 on all sides is the current I flowing to the capacitor 4-1 on the faulty side. decrease by I from ■
becomes. As a result, the load tonden is III.

1vL, 1=IVL1 Kara, itI row! J 7 ri)
Le 3-2 (r) 'J Ttance drop IvX21
is subtracted by lvL, l, but this change is lv Lzl
= about 0.95.

In the above practical example, the inverter failure detection means and the means for cutting off the AC switch may be any means in the prior art, and the means for extinguishing all the switching elements of the inverter may be a known extinguishing means, and the extinguishing means may be used for a predetermined period of time. felling,
Each operation may be carried out by known technical means such as a timer.

As explained above, the present invention includes means for extinguishing all switching elements of a failed inverter for a predetermined period of time in response to a change signal from an inverter failure detection means, and means for cutting off the AC switch for a predetermined period of time. Therefore, even if one inverter fails, by making small changes in the sleep current of the inverter on the construction side in two stages, it is possible to reduce the amount of variation in load solder pressure compared to conventional technology. effective.

[Brief explanation of the drawing]

FIG. 1 is a 1q path diagram of a conventional device, and a circuit diagram to which points and fa are added is an embodiment of the present invention. 2 to 4 are explanatory diagrams of the operation of the conventional installation, and FIGS. 5 and 6 are explanatory diagrams of the operation of the present invention. 1-1.1-2...Inverter, 2-1.2-2...
・AC switch, 3-1.3-2...1 giant column reactor, 4-1.4-2...parallel capacitor, 5-1.5
In the figures, the same reference numerals indicate parts corresponding to the same Id. Agent: Masu Oiwa H and No. 5 N/L2 Procedural amendment (self-abandonment) 59315 Showa year/Monday/Japanese Patent Office Commissioner R' is ',<'a,j 1, Indication of case Patent application No. 1983-68574 2,
Title of the invention: Power supply device 3, relationship to the amended case Patent applicant address: 2-2-3 Marunouchi, Chiyoda-ku, Tokyo Name (601) Mitsubishi Electric Corporation Representative Jinhachibe Katayama 4, Agent 5. Subject of amendment (1) Scope of claims in the specification (2) Detailed explanation of the invention in the specification (2) On page 4, line 12, "current goes to IT" is corrected to "current goes to Ig." (4) On page 5, lines 5 and 6, "means for extinguishing the arc for a predetermined time, after the predetermined time" has been replaced with "means for extinguishing the arc instantly and after a predetermined time after extinguishing the arc." (Correction: ``Means for extinguishing the arc for a predetermined period of time, after this predetermined time'' in lines 17 to 18 of page 7 of the same paragraph).
"After a predetermined period of time after the arc is extinguished." (6) Claims characterized by the three characters ``small'' that say ``Small change in two steps'' from page 7, line 20 to page 8, line 1 A series reactor and a parallel capacitor on the output side of the inverter In a power supply device in which multiple AC power supplies each having an AC switch connected to the load are connected in parallel to each other, an inverter failure detection means, and a signal from the detection means detects all switching elements of the failed inverter. A power supply device comprising means for extinguishing the arc, and means for cutting off the AC switch after a predetermined period of time.

Claims (1)

[Claims] In a power supply device in which an AC power supply device in which an AC switch is connected to the output side of the inverter via a series reactor and a parallel capacitor is connected in parallel to multiple loads, an inverter failure detection means is used, and a signal from this detection means is used to detect a failure inverter. A power supply device comprising means for extinguishing all switching elements for a predetermined period of time, and means for cutting off the AC switch after the predetermined period of time.