JPH0523795U - Power supply - Google Patents

Abstract

(57) [Summary] [Objective] The number of parts is smaller than that of the conventional device, and the device is simple and compact. [Structure] An input rectifier 2 for rectifying an input power source, first and second smoothing capacitors 14, 15 each having one end connected to each of positive and negative output terminals 2p, 2n of the rectifier 2, and a low voltage of the input power source. A connection selector 16 in which the other ends of the capacitors 14 and 15 are connected to the output terminals 2n and 2p, respectively, and the other ends of the capacitors 14 and 15 at the time of high voltage of the input power source are directly connected,
Two switching elements 9 and 1 for an inverter that are connected in series between the output terminals 2p and 2n and switch alternately
0, two DC cut / inverter power supply capacitors 17, 18 connected in series between the output terminals 2p, 2n, the connection point of the switching elements 9, 10 and the capacitors 17, 1
The primary winding 12a is provided between the connection point of 8 and the secondary winding 12
and an output transformer 12 having a load connected to b.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a power supply device having an inverter configuration which can be used with, for example, two types of AC power supplies of three-phase 200V system and 400V system.

[0002]

[Prior Art]

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

In the figure, 1a, 1b, and 1c are two types of three-phase AC power sources of low voltage (three-phase 200V system) and high voltage (three-phase 400V system). Phase input terminals, 2 are input rectifiers having 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 ends of the capacitors 4 and 5 are connected in series, and one end of the capacitor 6 is connected to the negative output terminal 2n of the rectifier 2.

Reference numerals 7 and 8 denote two connection switching devices. The switching device 7 switches between parallel and series connection of the capacitors 3 and 4, and the switching device 8 switches between parallel and serial connection of the capacitors 5 and 6. Be done. Reference numerals 9 and 10 denote two switching elements for an inverter, which are connected in series between the positive and negative output terminals 2p and 2n, each of which is composed of a transistor, an IGBT and the like, and constitutes an inverter together with the capacitors 3 to 6.

Reference numeral 11 denotes one DC-cutting capacitor whose one end is connected to a connection point of one ends of the capacitors 4 and 5, and 12 is a primary winding 12 a for connecting the other end of the capacitor 11 and the switching elements 9 and 10. An output transformer 13 provided between the transformer 12 and the point is an inductive load connected to the secondary winding 12b of the transformer 12. The capacitors 3 to 6 are usually formed of large-capacity electrolytic capacitors in order to sufficiently smooth the output of the rectifier 2. Further, the capacitor 11 is provided mainly for blocking a large direct current to prevent the magnetic bias of the transformer 12, 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, and the switch 8 is connected to the capacitor 5 , 6 having terminals e and f connected to the other end and capacitors g and h connected to one ends of the capacitors 6 and 5, respectively.

When the input power source is a low voltage power source of 200 V system, the switching device 7 is connected to the terminals a and c as well as the terminals b and d by manual or automatic switching, and the switching device 8 is connected to the switching device 8. The terminals e and g are connected and the terminals f and h are connected.

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

When the switching element 9 is turned on, a current flows through the parallel circuit of the switching element 9, the primary winding 12a, the capacitor 11 and the capacitors 5 and 6 until the capacitor 11 is charged, and the capacitors 3 and 4 are charged. Discharge, 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, the parallel circuit of the capacitors 3 and 4, the capacitor 11, the primary winding 12a, and the switching element 10 are charged until the capacitor 11 is charged. A current flows, the capacitors 5 and 6 are discharged, and the stored energy is supplied to the load 13 via the secondary winding 12b. Then, since switching of the switching elements 9 and 10 is repeated alternately, high-frequency AC power supply of inverter operation is performed to the load 13 based on the stored energy of the capacitors 3 to 6.

Next, when the input power source is a high-voltage power source of 400 V system, only the terminals a and b are connected to the switching device 7 and only the terminals e and f are connected to the switching device 8 by manual or automatic switching. To be done. 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.

Further, the switching elements 9 and 10 alternately switch based on the control signal of the control device, as in the case of the low voltage power supply. When the switching element 9 is turned on, a current flows in the 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 is discharged to store the stored energy. Are supplied to the load 13.

When the switching element 10 is turned on, a current flows through the series circuit of the capacitors 3 and 4, the capacitor 11, the primary winding 12a, and the switching element 10, and the series circuit of the capacitors 5 and 6 is discharged. The stored energy is supplied to the load 13. Then, 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 accumulated energy of the capacitors 3 to 6 as in the case where the input power supply is the low voltage power supply. Is done.

[0014]

[Problems to be solved by the device]

 In the case of the conventional apparatus of FIG. 2, smoothing of the output of the rectifier 2 and large-capacity and large-sized four capacitors 3 to 6 used for the inverter power supply are required, and two switchers 7 and 8 are required, and the number of parts However, there is a problem that it is complicated and large in size.

Even when the input power source is other than a three-phase AC power source such as a single-phase AC power source, the same problem as described above occurs because the configuration of the input rectifier is different. An object of the present invention is to provide a power supply device having a simple and compact inverter configuration, which has a large capacity, a large capacity capacitor, and a switching device.

[0016]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, in a power supply device of the present invention, an input rectifier for rectifying an input power source, and first and second smoothing capacitors having one ends connected to positive and negative output terminals of the rectifier, respectively. , One connection switcher that connects the other end of both smoothing capacitors at low voltage of the input power supply to the negative and positive output terminals of the input rectifier, and directly connects the other end of both smoothing capacitors at high voltage of the input power supply. , And two switching elements for the inverter that are connected in series between the positive and negative output terminals of the input rectifier and switch alternately, and two DC cuts connected in series between the positive and negative output terminals of the input rectifier. An output transformer in which a primary winding is provided between the connecting point of both the inverter power supply capacitor and both switching elements and the connecting point of both DC cut and inverter power supply capacitor, and the load is connected to the secondary winding. Provided with a door.

[0017]

[Action]

 In the case of the power supply device of the present invention configured as described above, two large-capacity and large-sized smoothing capacitors are connected to the input rectifier at the input of a low-voltage power supply by switching one connection switch. It is connected in parallel between the negative output terminals and is connected in series between the positive and negative output terminals of the input rectifier when the high voltage power supply is input. The output of the input rectifier is properly smoothed by the parallel circuit and the series circuit of both smoothing capacitors when the low voltage power supply or the high voltage power supply is input.

Further, the smoothed direct current uniformly charges the two small-capacity and small-capacitors for direct-current cutting and inverter power supply.

Then, due to the alternating switching of the two switching elements, both DC cut / inverter power supply capacitors are alternately discharged, and the stored energy is alternately supplied to the load via the output transformer. Inverter operation AC power is supplied. Therefore, with a simple and compact configuration that uses two large-capacity and large-capacitors and one switch, AC power supply for inverter operation can be performed when a low-voltage power supply or a high-voltage power supply is input.

[0020]

【Example】

 One embodiment will be described with reference to FIG. 1, the same reference numerals as those in FIG. 2 indicate the same or corresponding ones, and the points different from the conventional device in FIG. 2 are the following points (a), (a) and (c). (A) In place of the four capacitors 3 to 6 in FIG. 2, two smoothing capacitors 14 and 15 that only smooth the output of the rectifier 2 are provided, and one end of the capacitor 14 is connected to the positive output terminal 2p, One end of the capacitor 15 is connected to the negative output terminal 2n.

(A) A single connection switching device 16 is provided instead of the two connection switching devices 7 and 8 of FIG. 2, and the terminals i and j of this switching device 16 are connected to the other ends of the capacitors 14 and 15. Then, the terminals k 1 and l 2 are connected to the negative and positive output terminals 2n and 2p. (C) Instead of the capacitor 11 of FIG. 2, two DC cut / inverter power supply capacitors 17 and 18 which form an inverter together with the switching elements 9 and 10 are provided, and both ends of the series circuit of the capacitors 17 and 18 are positive. , Negative output terminals 2p and 2n. The capacitors 14 and 15 for smoothing the output of the rectifier 2 are formed of large-capacity and large-sized electrolytic capacitors, like the capacitors 3 to 6 in FIG.

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

When the input power source is a low voltage power source of 200 V system, the switching device 16 is connected to the terminals i and k as well as the terminals j and l 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, and the output of the rectifier 2 is sufficiently smoothed by the large-capacity parallel circuit of the capacitors 14 and 15.

Further, the smoothed outputs of the capacitors 14 and 15 uniformly charge the capacitors 17 and 18. 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. To be done.

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 to discharge the capacitor 18, and the stored energy is secondary. It is supplied to the load 13 via the winding 12. Then, switching of the switching elements 9 and 10 is repeated alternately, and since the capacities of the capacitors 17 and 18 are almost the same as those of the capacitor 11 of FIG. High-frequency AC power supply for inverter operation similar to the conventional one is supplied to 13.

Next, when the input power source is a high voltage power source of 400 V system, the terminals i and j of the switch 16 are connected by manual or automatic switching. At this time, capacitors 14 and 15 are connected in series between the positive and negative output terminals 2p and 2n, and the series circuit of the capacitors 14 and 15 increases the breakdown voltage and smoothes the output of the rectifier 2.

Further, the smoothed outputs of the capacitors 14 and 15 uniformly charge the capacitors 17 and 18. Then, when the switching elements 9 and 10 are turned on, a current flows through the same loop as in the case of the low voltage power supply, the capacitors 17 and 18 are discharged, the secondary winding 12b supplies power to the load 13, and the load 13 drives the inverter. High-frequency AC power is supplied for operation.

Therefore, as a large-capacity and large-capacity capacitor, only two capacitors 14 and 15 having a withstand voltage of 200V are provided, and one switch 16 is used to connect the capacitors 14 and 15 according to the 200V-system and 400V-system of the input power source. By switching the connection of 15 in parallel or in series, both 200V and 400V power supply can be performed. Although the capacitors 17 and 18 have a higher breakdown voltage than the capacitor 11 of FIG. 2, for example, they may have a small capacity, and are sufficiently smaller and smaller than the capacitors 14 and 15 and the capacitors 3 to 6 of FIG.

By the way, in the above embodiment, the low voltage and high voltage of the input power source are the three-phase 200V system and the 400V system, but two kinds of various voltages of single phase and multiphase are the low voltage and the high voltage. Of course, the voltage may be used.

[0030]

[Effect of the device]

 Since the present invention is configured as described above, it has the following effects. By switching one connection switching device 16 based on low voltage and high voltage of the input power source, the first and second smoothing capacitors 14 and 15 are connected in parallel between the positive and negative output terminals 2p and 2n of the input rectifier 2. Connected by switching in series, the output of the input rectifier 2 is properly smoothed by the capacitors 14 and 15 when the input power supply is at low voltage and high voltage, and the DC output and the capacitor for inverter power supply 17 are provided by the smoothed output of the capacitors 14 and 15. , 18 are charged, and the energy stored in the capacitors 17, 18 is supplied to the load 13 via the output converter 12 by the alternating switching of the switching elements 9, 10 that form an inverter together with the capacitors 17, 18, so that the rectifier There are only two large capacitors, large capacitors necessary for smoothing 2, capacitors 14 and 15, and the internal circuit based on the low voltage and high voltage is used. The connection switching can be performed by only one switching device 16 becomes simple and small number of parts than conventional equipment is low.

[Brief description of 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 1st, 2nd smoothing capacitor 16 Connection changer 17,18 DC cut and capacitor for inverter power supply

Claims (1)

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