JPH10117476A - Rectifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rectifier, which is capable of preventing the concentration of current in a specific current path by balancing the currents in positive and a negative pole-side current path in each of non-insulated rectifiers which are connected in parallel. SOLUTION: In the after stages of rectifying circuits 12a, 12b of non-insulated rectifiers 11a, 11b of a rectifying equipment 1, reactors X1a, X2a and reactors X1b, X2b, each of which is constituted of a coil dividedly wound around one and the same iron core, are serially connected to the positive and the negative pole sides respectively. Due to this structure, currents in a positive and a negative pole-side current path are balanced in each of the non-insulated rectifiers 11a, 11b, and the concentration of current in a specific current path can be prevented and thereby current larger than the rated one is prevented form flowing into diodes D1, D3, D7, D9 of the rectifying circuits 12a, 12b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rectifier, and more particularly to a rectifier in which a plurality of non-insulated rectifiers each having a rectifier circuit and a DC converter are connected in parallel.

[0002]

2. Description of the Related Art FIG. 2 shows a circuit configuration of a conventional rectifier in which two non-insulated rectifiers each having a rectifier circuit and a DC converter circuit are connected in parallel. In FIG. 1, the rectifier 2 includes two non-insulated rectifiers 21a and 21b connected in parallel.

[0003] The non-insulated rectifier 21a is a rectifier circuit 12a.
a, DC chopper circuit 22a, filter capacitor C
1 and a block diode D6. The rectifier circuit 12a is a circuit that converts an AC voltage supplied from the AC power supply 5 into a DC voltage, and performs full-wave rectification by four diodes D1 to D4 connected in a bridge.

[0006] The DC chopper circuit 22 a
This circuit is connected to the output stage a and converts the DC voltage output from the rectifier circuit 12a into DC voltages having different voltage values. The DC chopper circuit 22a is a step-down chopper circuit that obtains an output voltage having a voltage value lower than the input voltage, and includes a switching element S1 such as a transistor, a flywheel diode D5, and a reactor X3.

The DC voltage converted to a desired voltage value by the DC chopper circuit 22a is supplied to a filter capacitor C1, which is connected to an output stage of the DC chopper circuit 22a.
And the load 6 via the block diode D6.

The other non-insulated rectifier 21b
Has a circuit configuration similar to that of the non-insulated rectifier 21a as shown in FIG. Accordingly, a DC voltage is supplied to the load 6 connected to the rectifier 2 from the two non-insulated rectifiers 21a and 21b connected in parallel.

[0007]

However, such a conventional rectifier 2 has the following problems.

That is, as shown in FIG.
In the case of a cycle in which a negative voltage is applied to a point, the current path in the non-isolated rectifier 21a extends from the AC power supply 5 to the positive electrode side of the load 6 via the diode D2, the switching element S1, the reactor X3, and the block diode D6. ,
AC power supply 5 from the negative side of load 6 via diode D3
Return to The current path in the non-insulated rectifier 21b at this time conforms to the current path in the non-insulated rectifier 21a.

However, at this time, the current path on the negative electrode side of the non-insulated rectifier 21a is connected to the other non-insulated rectifier 2a.
The path may return to the AC power supply 5 via the diode D9 of 1b. The same applies to the current path on the negative electrode side in the non-insulated rectifier 21b. The same applies to a cycle in which a negative voltage is applied to point A and a positive voltage is applied to point B.

For this reason, in a cycle in which the current path on the negative electrode side is concentrated on one side and a positive voltage is applied to the point A and a negative voltage is applied to the point B, the current is supplied to the diode D3 or the diode D9. In the case of a cycle in which a negative voltage is applied to point B and a positive voltage is applied to point B, there is a problem that a current higher than the rated current flows in diode D1 or diode D7.

Further, in order to solve the above problem, FIG.
As shown in (1), a method is known in which transformer circuits 32a and 32b are provided in front of the rectifier circuits 12a and 12b, and the AC power supply 5 and the rectifier circuits 12a and 12b are insulated by transformers T1 and T2. The provision of the transformers T1 and T2 has a problem that the power efficiency is reduced, the mass of the device is increased, or the device is increased in size.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and balances the currents flowing through the current paths on the positive electrode side and the negative electrode side for each non-insulated rectifier connected in parallel. It is another object of the present invention to provide a rectifier that prevents current from concentrating on a specific current path.

[0013]

A rectifier according to the present invention includes a rectifier for converting an AC voltage supplied from an AC power supply into a DC voltage, and a rectifier connected downstream of the rectifier to convert the DC voltage into a voltage. A plurality of non-insulated rectifiers having a DC conversion circuit for converting to different DC voltages are connected in parallel between the AC power supply and the load, and a predetermined DC voltage is applied to the load from each of the non-insulated rectifiers. Wherein each of the non-insulated rectifiers is provided at a subsequent stage of the rectifier circuit.
A first reactor and a second reactor formed by coils wound by being divided into the same magnetic core are connected in series to a positive electrode side and a negative electrode side, respectively, and a positive electrode side and a negative electrode are connected to each non-insulated rectifier. It is characterized in that the current flowing in the current path on the side is balanced.

Therefore, according to the rectifier of the present invention, the first reactor and the second reactor formed by the coil divided and wound on the same magnetic core are provided at the subsequent stage of the rectifier circuit of each non-insulated rectifier. Since the reactor and the reactor are connected in series to the positive and negative electrodes, respectively, the current flowing in the positive and negative current paths can be balanced for each non-insulated rectifier, and the current to a specific current path can be balanced. Concentration can be prevented, and a current exceeding a rating can be prevented from flowing through a specific circuit element. As a result, the reliability of the rectifier can be improved. In addition, since there is no need to provide a transformer circuit and a transformer is unnecessary, the power efficiency decreases, the mass of the device increases,
Alternatively, the problem of an increase in the size of the device can be solved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to FIG. First, the configuration will be described.

FIG. 1 is a circuit diagram of a rectifier 1 to which the present invention is applied. In the figure, the same components as those in the circuit diagram of the rectifier 2 (see FIG. 2) shown as a conventional example are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 1, the rectifier 1 includes two non-insulated rectifiers 11a and 11b connected in parallel.

The non-insulated rectifier 11a includes a rectifier circuit 12
a, DC chopper circuit 13a, filter capacitor C
1 and a block diode D6. The DC chopper circuit 13a includes a switching element S1 such as a transistor, a flywheel diode D5,
And reactors X1a and X1b formed by coils wound separately on the same core for the positive electrode side and the negative electrode side.

The other non-insulated rectifier 11b
Has a circuit configuration similar to that of the non-insulated rectifier 11a as shown in FIG. Therefore, a DC voltage is supplied to the load 6 connected to the rectifier 1 from the two non-insulated rectifiers 11a and 11b connected in parallel. The above is the configuration of the rectifier 1 according to the present embodiment.

Next, the operation will be described. The rectifier 1
Are connected in parallel with non-insulated rectifiers 11a and 11b having the same circuit configuration.
The explanation will be made mainly with.

Rectifier circuit 12a of non-insulated rectifier 11a
Converts the AC voltage supplied from the AC power supply 5 into a DC voltage (full-wave rectification), and outputs the DC voltage to the DC chopper circuit 13a. In the DC chopper circuit 13a, the DC voltage supplied from the rectifier circuit 12a is reduced to a desired voltage value and supplied to the load 6 via the filter capacitor C1 and the blocking diode D6.

At this time, the reactors X1a and X1b are connected in series to the positive electrode side and the negative electrode side, respectively, in the DC chopper circuit 13a, and both the reactors X1a and X1b are connected.
b is formed by coils wound separately on the same core for the positive electrode side and the negative electrode side, so that both reactors X
1a and X1b minimize the occurrence of a deviation between the current flowing in the positive current path and the current flowing in the negative current path.

Therefore, it is possible to balance the current flowing in the current path on the positive electrode side of the non-insulated rectifier 11a with the current flowing in the current path on the negative electrode side. The same can be said for the other non-insulated rectifier 11b. Therefore, in the rectifier 1, each non-insulated rectifier 11
It is possible to balance currents flowing through the current paths on the positive electrode side and the negative electrode side for each of a and 11b. The above is the operation procedure of the rectifier 1 according to the present embodiment.

In this embodiment, the DC chopper circuits 13a, 13a of the non-insulated rectifiers 11a, 11b are used.
3b, a first reactor (reactor X1) is formed by dividing the reactor as a component into a positive electrode side and a negative electrode side.
a, X2a) and a second reactor (reactor X1b,
X2b) is provided, but the present invention is not limited to the above-described contents. The first and second coils formed of the same core and wound around the output stages of the rectifier circuits 12a and 12b (later stages) are provided. Reactors (reactors X1a, X2
a) and the second reactor (reactors X1b, X2b)
Are connected in series to the positive electrode side and the negative electrode side, respectively.

As described above, according to the rectifier 1 of the present embodiment, each of the non-insulated rectifiers 11a and 11
b, a reactor X formed by a coil divided and wound on the same iron core is provided downstream of the rectifier circuits 12a and 12b.
1a, X2a (first reactor) and reactor X1
b and X2b (second reactor) are connected in series to the positive electrode side and the negative electrode side, respectively, so that the current flowing through the current paths on the positive electrode side and the negative electrode side for each of the non-insulated rectifiers 11a and 11b is balanced. Therefore, it is possible to prevent a current from concentrating on a specific current path, and to prevent a current exceeding a rating from flowing through the diodes D1, D3, D7, and D9 of the rectifier circuits 12a and 12b. Further, since there is no need to provide a transformer circuit and a transformer is not required, problems such as a decrease in power efficiency, an increase in the mass of the device, and an increase in the size of the device can be solved.

As described above, the present invention has been specifically described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist thereof. Of course there is.

For example, in the rectifier 1 of the above embodiment, two non-insulated rectifiers 11a and 11b are connected in parallel, but the number of non-insulated rectifiers connected in parallel is two. The number is not limited to this, and may be any number as long as the number is plural.

Further, in the above-described embodiment, a step-down chopper circuit has been described as an example of a DC conversion circuit. However, this may be a step-up chopper circuit, and further, other than these DC chopper circuits. In other words, any circuit may be used as long as it converts an input DC voltage into DC voltages having different voltage values.

In the above embodiment, the magnetic core is an iron core. However, the present invention is not limited to the above description, and the material of the magnetic core may be silicon steel, permalloy, ferrite, or the like.

[0029]

According to the rectifier of the present invention, the first reactor and the second reactor formed by the coil divided and wound on the same magnetic core are provided downstream of the rectifier circuit of each non-insulated rectifier.
Are connected in series to the positive and negative electrodes, respectively, so that the current flowing to the positive and negative current paths can be balanced for each non-insulated rectifier, and the current to a specific current path can be balanced. Concentration can be prevented, and a current exceeding a rating can be prevented from flowing through a specific circuit element. As a result, the reliability of the rectifier can be improved. Further, since there is no need to provide a transformer circuit and a transformer is not required, problems such as a decrease in power efficiency, an increase in the mass of the device, and an increase in the size of the device can be solved.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a rectifier to which the present invention is applied.

FIG. 2 is a circuit diagram of a conventional rectifier (non-insulated type).

FIG. 3 is a circuit diagram of a conventional rectifier (insulation type).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rectifier 5 AC power supply 6 Load 11a, 11b Rectifier 12a, 12b Rectifier circuit 13a, 13b DC chopper circuit

Claims (1)

[Claims] 1. A rectifier circuit for converting an AC voltage supplied from an AC power supply into a DC voltage, and a DC converter circuit connected to a subsequent stage of the rectifier circuit and converting the DC voltage into DC voltages having different voltage values. A plurality of non-insulated rectifiers are connected in parallel between the AC power supply and the load, and a rectifier that supplies a predetermined DC voltage to the load from each of the non-insulated rectifiers. A first type rectifier is formed by a coil which is divided and wound on the same magnetic core at a subsequent stage of the rectifier circuit.
And the second reactor are connected in series to the positive electrode side and the negative electrode side, respectively, and for each of the non-insulated rectifiers, the current flowing in the current paths on the positive electrode side and the negative electrode side is balanced. Rectifier.