JP2551403Y2 - Power supply - Google Patents

Description

[Detailed description of the invention]

[0001]

The present invention relates to, for example, a three-phase 200 V
The present invention relates to a power supply device having an inverter configuration that can be used with any of two types of AC power supplies, i.

[0002]

2. Description of the Related Art Conventionally, a power supply device having an inverter configuration of this type is configured as shown in FIG. 2 when an input power supply is a three-phase AC power supply.

In FIG. 1, reference numerals 1a, 1b, and 1c denote two types of low-voltage (three-phase 200V system) and high-voltage (three-phase 400V system) three-phase AC power supplies, which are selectively applied as input power supplies.
Phase input terminal, 2 is an input rectifier of a diode rectifier configuration,
3, 4, 5, and 6 are four smoothing and inverter power supply capacitors, one end of the capacitor 3 is connected to the positive output terminal 2p of the rectifier 2, one end of the capacitors 4 and 5 is connected in series, and the capacitor 6 is One end is a negative output terminal 2n of the rectifier 2.
It is connected to the.

[0004] Reference numerals 7 and 8 denote two connection switches. The switch 7 switches the connection of the capacitors 3 and 4 in parallel or in series. The switch 8 switches the connection of the capacitors 5 and 6 in parallel.
The series is switched. 9, 10 are positive and negative output terminals 2p,
Two switching elements for the inverter connected in series between 2n, each including a transistor, an IGBT, etc., and constitute an inverter together with the capacitors 3 to 6.

Reference numeral 11 denotes one DC cut capacitor having one end connected to a connection point between one end of the capacitors 4 and 5;
Is an output transformer in which a primary winding 12a is provided between the other end of the capacitor 11 and a connection point of the switching elements 9 and 10, and 13 is an inductive transformer connected to a secondary winding 12b of the transformer 12. It is a load. Note that the capacitors 3 to 6 are usually formed of large-capacity electrolytic capacitors, respectively, in order to sufficiently smooth the output of the rectifier 2. Further, the capacitor 11 is mainly provided to interrupt a large DC current to prevent the transformer 12 from being demagnetized, and is usually set to a small capacity.

On the other hand, the switch 7 has terminals a and b connected to the other ends of the capacitors 3 and 4 and terminals c and d connected to one ends of the capacitors 4 and 3, respectively. 6 has terminals e and f connected to the other ends and terminals g and h connected to one ends of the capacitors 6 and 5.

When the input power supply is a low-voltage power supply of 200 V system, the switch 7 is connected to the terminals a and c and the terminals b and d by manual or automatic switching.
The switch 8 has terminals e and g connected and terminals f and h.
Is connected.

At this time, capacitors 3 and 4 are connected in parallel and capacitors 5 and 6 are connected in parallel, and a parallel circuit of capacitors 3 and 4 and a parallel circuit of smoothing capacitors 5 and 6 are connected between positive and negative output terminals 2p and 2n. The circuit is connected in series and the output of the rectifier 2 is smoothed. Further, the switching elements 9 and 10 alternately perform high-frequency switching every half cycle of the set power supply AC of the load 13 according to a control signal of a control device (not shown).

When the switching element 9 is turned on, a current flows through a parallel circuit of the switching element 9, the primary winding 12a, the capacitors 11 and the capacitors 5 and 6 until the capacitor 11 is charged, and the capacitors 3 and 4 are turned on. Discharge occurs and the stored energy is supplied to the load 13 via the secondary winding 12b.

When the switching element 9 is turned off and the switching element 10 is turned on, a current flows through the parallel circuit of the capacitors 3 and 4, the capacitor 11, the primary winding 12a, and the switching element 10 until the capacitor 11 is charged. Then, the capacitors 5 and 6 discharge, and the stored energy is supplied to the load 13 through the secondary winding 12b. Since the switching of the switching elements 9 and 10 is alternately repeated, high-frequency AC power is supplied to the load 13 by the inverter operation based on the energy stored in the capacitors 3 to 6.

Next, when the input power supply is a high-voltage power supply of a 400 V system, only the terminals a and b are connected to the switch 7 and only the terminals e and f are connected to the switch 8 by manual or automatic switching. You. At this time, the capacitors 3 to 6 are connected in series between the positive and negative output terminals 2p and 2n to increase the breakdown voltage and smooth the output of the rectifier 2.

The switching elements 9 and 10 alternately switch on the basis of a control signal from the control device, as in the case of the low-voltage power supply. When the switching element 9 is turned on, a current flows through a series circuit of the switching element 9, the primary winding 12a, the capacitor 11, and the capacitors 5 and 6, and the series circuit of the capacitors 3 and 4 discharges. 13 is supplied.

When the switching element 10 is turned on, the series circuit of the capacitors 3 and 4 and the capacitors 11 and
A current flows through the primary winding 12a and the switching element 10 to discharge the series circuit of the capacitors 5 and 6, and the stored energy is supplied to the load 13. Since the high-frequency switching of the switching elements 9 and 10 is alternately repeated, the high-frequency AC power supply of the inverter operation is supplied to the load 13 based on the energy stored in the capacitors 3 to 6 as in the case of the low-voltage power supply. Done.

[0014]

The conventional apparatus shown in FIG. 2 requires four large-capacity, large-sized capacitors 3 to 6 used for smoothing the output of the rectifier 2 and for the inverter power supply, and two switchers 7. , 8 and there is a problem that the number of parts is large and complicated and large.

When the input power supply is other than a three-phase AC power supply such as a single-phase AC power supply, the same problem as described above occurs because only the configuration of the input rectifier is different. SUMMARY OF THE INVENTION It is an object of the present invention to provide a simple and compact power supply device having a small number of large-capacity, large-sized capacitors and switches.

[0016]

In order to achieve the above object, in the power supply device of the present invention, an input rectifier for rectifying an input power and one end is connected to each of positive and negative output terminals of the rectifier. The other ends of the first and second smoothing capacitors are connected to the negative and positive output terminals of the input rectifier when the input power supply is at a low voltage, and the other ends of the smoothing capacitors are directly connected when the input power supply is at a high voltage. One connection switching device, two switching elements for an inverter which are connected in series between the positive and negative output terminals of the input rectifier and alternately switch, and are connected in series between the positive and negative output terminals of the input rectifier. A primary winding is provided between the connection point of the two DC cut and inverter power supply capacitors and the connection point of the two switching elements and the connection point of the both DC cut and inverter power supply capacitors. There and an output transformer connected.

[0017]

In the power supply device of the present invention configured as described above, two large-capacity and large-sized smoothing capacitors are switched by one connection switch to correct the input rectifier when the low-voltage power supply is input. , Is connected in parallel between the positive and negative output terminals of the input rectifier when a high voltage power supply is input. Then, the output of the input rectifier is appropriately smoothed by the parallel circuit and the series circuit of the both smoothing capacitors, regardless of whether the low-voltage power supply or the high-voltage power supply is input.

Furthermore, the two smooth and formed direct currents uniformly charge the two small-capacity and small-sized direct current cut and inverter power supply capacitors.

By alternately switching the two switching elements, the capacitors for both DC cut and inverter power supply are alternately discharged, and the stored energy is alternately supplied to the load via the output transformer. Of the inverter operation. Therefore, with a simple and small configuration in which two large-capacity and large-sized capacitors are used and one switch is used, AC power supply for inverter operation can be performed when a low-voltage power supply or a high-voltage power supply is input.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment will be described with reference to FIG. 1, the same reference numerals as those in FIG. 2 denote the same or corresponding elements, and the points different from the conventional apparatus in FIG. 2 are the following points (A), (A), and (C). (A) Instead of the four capacitors 3 to 6 in FIG. 2, two smoothing capacitors 14, which only smooth the output of the rectifier 2,
15, one end of the capacitor 14 is connected to the positive output terminal 2p, and one end of the capacitor 15 is connected to the negative output terminal 2n.

(A) Instead of the two connection switches 7 and 8 in FIG. 2, one connection switch 16 is provided, and the terminals i and j of this switch 16 are connected to the other ends of the capacitors 14 and 15. Then, the terminals k and l are connected to the negative and positive output terminals 2n and 2p. (C) In place of the capacitor 11 of FIG. 2, two DC cut and inverter power supply capacitors 17 and 18 constituting an inverter together with the switching elements 9 and 10 are provided.
Both ends of the series circuit of the capacitors 17 and 18 are connected to the positive and negative output terminals 2p and 2n. The capacitors 14 and 15 for smoothing the output of the rectifier 2 are capacitors 3 to 3 in FIG.
As in the case of 6, it is formed by a large-capacity, large-sized electrolytic capacitor.

The capacitors 17 and 18, which are used both for preventing the transformer 12 from demagnetizing and for the inverter power supply, are set to have the same small capacity as the capacitor 11 of FIG. further,
The primary winding 12a of the transformer 12 is provided between a connection point of the capacitors 17 and 18 and a connection point of the switching elements 9 and 10.

When the input power supply is a low-voltage power supply of 200V system, the terminals i and k and the terminals j and l are connected to the switch 16 by manual or automatic switching. At this time, the capacitors 14 and 15 are connected in parallel between the positive and negative output terminals 2p and 2n.
With the large-capacity parallel circuit of 5, the output of the rectifier 2 is sufficiently smoothed.

The capacitors 17, 18 are charged uniformly by the smoothed outputs of the capacitors 14, 15. When the switching element 9 is turned on, a current flows through the switching element 9, the primary winding 12a, and the capacitor 18 to discharge the capacitor 17, and the stored energy is supplied to the load 13 via the secondary winding 12b. .

When the switching element 9 is turned off and the switching element 10 is turned on, a current flows through the capacitor 17, the primary winding 12a, and the switching element 10, and the capacitor 18 is discharged. 12
Is supplied to the load 13 via the. The switching of the switching elements 9 and 10 is alternately repeated, and the capacitance of the capacitors 17 and 18 is substantially the same as that of the capacitor 11 of FIG. Then, the high-frequency AC power supply of the inverter operation similar to the conventional one is performed.

Next, when the input power supply is a high voltage power supply of a 400 V system, the terminals i and j are connected to the switch 16 by manual or automatic switching. At this time, the positive and negative output terminals 2
Capacitors 14 and 15 are connected in series between p and 2n, and the withstand voltage is increased by the series circuit of the capacitors 14 and 15 so that the output of the rectifier 2 is smoothed.

The capacitors 17 and 18 are uniformly charged by the smoothed outputs of the capacitors 14 and 15. When the switching elements 9 and 10 are turned on, current flows through the same loop as in the case of the low-voltage power supply, and the capacitor 1
7 and 18 are discharged to load 1 from the secondary winding 12b.
3 and the load 13 is supplied with high-frequency AC power supplied by inverter operation.

Therefore, only two capacitors 14 and 15 having a withstand voltage of 200 V system are provided as a large-capacity and large-sized capacitor.
By switching the connection of the capacitors 14 and 15 in parallel or in series according to the system and the 400 V system,
Any power supply of the V system can be performed. The capacitors 17,
For example, the capacitor 18 has a higher withstand voltage than the capacitor 11 in FIG. 2, but may have a small capacity, and has a sufficiently small capacity and small size compared to the capacitors 14, 15 and the capacitors 3 to 6 in FIG.

In the above-described embodiment, the low voltage and the high voltage of the input power source are three-phase 200 V system and 400 V system.
Needless to say, two kinds of single-phase and multi-phase voltages may be set to the low voltage and the high voltage.

[0030]

The present invention is configured as described above and has the following effects. By switching one connection switch 16 based on the low voltage and high voltage of the input power source, the first and second smoothing capacitors 14 and 15 are connected in parallel and in series between the positive and negative output terminals 2p and 2n of the input rectifier 2. The output of the input rectifier 2 is appropriately smoothed by the capacitors 14 and 15 when the input power supply is at a low voltage or a high voltage, and the DC cut and inverter power supply capacitors 17 and 18 are provided by the smoothed outputs of the capacitors 14 and 15. Charge
The energy stored in the capacitors 17 and 18 is supplied to the load 13 via the output converter 12 by alternately switching the switching elements 9 and 10 constituting an inverter together with the capacitors 17 and 18, so that the large amount necessary for smoothing the rectifier 2 is obtained. Capacitor, large capacitor is replaced by capacitor 14,
15, only one switch 16 can be used to switch the internal connection based on the low voltage and the high voltage. The number of parts is smaller than that of the conventional device, and the device is simpler and smaller.

[Brief description of the drawings]

FIG. 1 is a connection diagram of an embodiment of a power supply device of the present invention.

FIG. 2 is a connection diagram of a conventional device.

[Explanation of symbols]

 2 Input rectifier 2p Positive output terminal 2n Negative output terminal 9,10 Switching element 12 Output transformer 12a Primary winding 12b Secondary winding 13 Load 14,15 First and second smoothing capacitor 16 Connection switch 17,18 DC cut and capacitor for inverter power supply

Claims (1)

(57) [Scope of request for utility model registration] 1. An inverter-type power supply device that operates by using two types of low-voltage and high-voltage AC power supplies as input power supplies by switching internal connections, comprising: an input rectifier that rectifies the input power; First and second smoothing capacitors each having one end connected to a negative output terminal, and the other end of each of the two smoothing capacitors being connected to the negative and positive output terminals of the input rectifier when the input power supply is at a low voltage; A connection switch for directly connecting the other ends of the both smoothing capacitors when the input power supply is at a high voltage; and two switching elements for an inverter which are connected in series between the positive and negative output terminals of the input rectifier and alternately switch. 2 connected in series between the positive and negative output terminals of the input rectifier.
A primary winding is provided between the connection point of the two switching elements and the connection point of the two DC cut and inverter power supply capacitors, and a load is connected to the secondary winding. Power supply with an output transformer.