JP7158319B2 - power supply - Google Patents

Description

The present invention relates to a power supply device for supplying a large current to an inductive load.

2. Description of the Related Art As a power supply for supplying a large current to an inductive load such as a magnetic field generator, a capacitor storage power supply is known (see, for example, Patent Document 1). A capacitor storage power supply stores a large amount of energy in advance in a capacitor, operates a discharge switch to discharge the capacitor, and supplies the discharged current to a coil serving as an inductive load.

A large-current switch such as a gap switch or an ignitron is used as the discharge switch. FIG. 4 shows a power supply device 100B having a gap switch 21. As shown in FIG. Power supply device 100</b>B further includes capacitor 22 , charging resistor 23 , charger 24 , protective reactor 25 , crowbar circuit 26 , and discharging circuit 27 .

After the capacitor 22 is charged by the charger 24 via the charging resistor 23, the power supply device 100B turns on the gap switch 21 to transfer the discharge current of the capacitor 22 to the inductive load 200 connected to the output terminals T1 and T2. supply to

In the power supply device 100B, the output terminals T1 and T2 may become open due to poor connection or poor contact of the inductive load 200, but in the case of the gap switch 21, there was no particular problem.

On the other hand, in recent years, there has been a demand for switches to be made of semiconductors in order to improve the stability of switches and reduce running costs. If a semiconductor switch (for example, a thyristor) is used instead of the gap switch 21, it is necessary to connect a voltage equalizing resistor in parallel with the semiconductor switch.

However, in the above configuration, when the output terminals T1 and T2 are in an open state, the charged voltage of the capacitor leaks through the equalizing resistors, resulting in a high voltage at the output terminals T1 and T2.

As shown in FIG. 5, when the output terminals T1 and T2 are open, when the charger 24 is turned _on at time t11 to start charging the capacitor 22, the charged voltage Vc of the capacitor 22 rises and the output terminal T1 , T2 also rises.

When the semiconductor switch is turned _on at time t12, the charging voltage Vc of the capacitor 22 is applied to the output terminals T1 and T2 while a high voltage is generated at the output terminals T1 and T2. It rises greatly beyond Vc. The reason why the output current appears at time t12 is that floating capacitance exists _on the output terminals T1 and T2.

As a result, in a conventional power supply device using a semiconductor switch, when the output terminals T1 and T2 are in an open state, a high voltage is generated at the output terminals T1 and T2, which may cause damage or failure of components in the power supply device 100B. have a nature. In addition, in order to avoid damage or failure of parts due to high voltage, it is necessary to select excessive parts, leading to an increase in cost.

JP-A-7-192918

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a power supply device capable of suppressing generation of a high voltage at the output terminal when the output terminal is in an open state. .

In order to solve the above problems, the power supply device according to the present invention includes:
A power supply for supplying output current to an inductive load, comprising:
an output terminal to which the inductive load is connected;
a capacitor that outputs a discharge current as the output current;
a charger for charging the capacitor;
a semiconductor switch interposed in a discharge current path between the capacitor and the output terminal;
a first voltage equalizing resistor connected in parallel to the semiconductor switch;
a detecting means for detecting whether the output terminal is in an open state;
a control unit that controls the charger;
with
The control unit
causing the charger to start pre-charging, performing a self-diagnosis as to whether or not the output terminal is in an open state based on the detection result of the detecting means, and stopping the pre-charging when it is diagnosed that the output terminal is in an open state; a first charging process;
and a second charging process of causing the charger to perform main charging so that the charging voltage reaches a predetermined voltage value when the self-diagnosis does not determine that the battery is in an open state. and

According to this configuration, the control unit causes the charger to start pre-charging, performs self-diagnosis as to whether or not the output terminal is in an open state, and stops pre-charging when it is diagnosed as being in an open state. , it is possible to suppress the generation of a high voltage at the output terminal when the output terminal is in an open state.

In the above power supply,
The detection means is
a first voltage detection means for detecting an output terminal voltage generated at the output terminal;
a second voltage detection means for detecting the charging voltage of the capacitor;
has
The control unit controls the charger according to the detection results of the first voltage detection means and the second voltage detection means, and controls the output end voltage to a predetermined level when the first charging process is performed. By comparing with a threshold value, it is possible to perform self-diagnosis as to whether or not the output terminal is in an open state.

In the above power supply,
The control unit
It is preferable that the pre-charging is switched to the main charging without stopping the charging of the capacitor when the self-diagnosis does not determine that the capacitor is in an open state.

In the above power supply,
The semiconductor switch is composed of a plurality of thyristors connected in series,
The first pressure-equalizing resistor may be composed of a plurality of resistors connected in parallel to each of the plurality of thyristors.

In the above power supply,
further comprising a crowbar circuit provided between the semiconductor switch and the output terminal;
The crowbar circuit is
a series circuit consisting of a diode and a resistor;
a second voltage equalizing resistor connected in parallel to the diode;
can be configured to provide

ADVANTAGE OF THE INVENTION According to this invention, the power supply device which can suppress that a high voltage arises in an output terminal when an output terminal is an open state can be provided.

1 is a circuit diagram of a power supply device according to the present invention; FIG. FIG. 4 is a diagram showing the operation of the power supply device according to the present invention when the output terminal is in an open state; FIG. 5 is a diagram showing the operation of the power supply device according to the present invention when the output terminal is in a normal state; 1 is a circuit diagram of a conventional power supply; FIG. FIG. 10 is a diagram showing the operation of a conventional power supply device when the output terminal is in an open state;

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a power supply device according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a power supply device 100A according to one embodiment of the present invention. The power supply device 100A supplies a large current to the inductive load 200 connected to the output terminals T1 and T2. The inductive load 200 has a secondary coil (not shown) connected to a strong magnetic field generator.

The power supply device 100A includes a capacitor 1, a charging resistor 2, a charger 3, a semiconductor switch 4, a protective reactor 5, a first voltage equalizing resistor 6, a crowbar circuit 7, a discharging circuit 8, a first voltage Detector 9 , second voltage detector 10 , and controller 11 .

Capacitor 1 is composed of one or more capacitors. One end of capacitor 1 is connected to the high potential side of charger 3 via charging resistor 2 , and the other end of capacitor 1 is connected to the low potential side of charger 3 . The charger 3 outputs a DC voltage under the control of the controller 11 to charge the capacitor 1 .

The semiconductor switch 4 is composed of one or a plurality of thyristors connected in series. The anode side of the semiconductor switch 4 is connected to one end of the capacitor 1 , and the cathode side of the semiconductor switch 4 is connected to the output terminal T 1 on the high potential side via the protective reactor 5 . That is, the semiconductor switch 4 is interposed in the discharge current path between the capacitor 1 and the output terminal T1.

A first voltage equalizing resistor 6 is connected in parallel with the semiconductor switch 4 . For example, when the semiconductor switch 4 is composed of a first thyristor, a second thyristor, and a third thyristor, the first pressure equalizing resistor 6 is connected in parallel to the first resistor and the second thyristor, which are connected in parallel to the first thyristor. and a third resistor connected in parallel to the third thyristor. Each of the first to third resistors is composed of one or more resistors.

The crowbar circuit 7 includes a series circuit composed of a diode 12 and a resistor 13 and a second voltage equalizing resistor 14 connected in parallel to the diode 12 . The cathode side of the diode 12 is connected to the connection point between the semiconductor switch 4 and the protective reactor 5, and the anode side of the diode 12 is connected via the resistor 13 to the output terminal T2 on the low potential side. Diode 12 is composed of one or a plurality of diodes connected in series. The second voltage equalizing resistor 14 is composed of one or more resistors, like the first voltage equalizing resistor 6 . That is, when the diode 12 is composed of a plurality of diodes, each resistor constituting the second voltage equalizing resistor 14 is connected in parallel to each of the plurality of diodes.

Discharge circuit 8 comprises a series circuit consisting of switch 15 and resistor 16 . The discharge circuit 8 forms a discharge current path for the capacitor 1 by, for example, turning on the switch 15 in the event of an abnormality. The switch 15 is composed of a semiconductor switch such as an IGBT. One end of the discharge circuit 8 is connected to one end of the capacitor 1 and the other end of the discharge circuit 8 is connected to the other end of the capacitor 1 .

The first voltage detection means 9 detects the output terminal voltage Vo generated at the output terminals T1 and T2. The detection result of the first voltage detection means 9 is output to the control section 11 at a predetermined cycle. Although the first voltage detection means 9 is provided after the protection reactor 5 in this embodiment, it may be provided before the protection reactor 5 and after the crowbar circuit 7 .

A second voltage detection means 10 detects a charging voltage Vc of the capacitor 1 . The detection result of the second voltage detection means 10 is output to the control section 11 at a predetermined cycle.

The controller 11 controls the charger 3 and the semiconductor switch according to the detection result (the voltage value of the output terminal voltage Vo) of the first voltage detection means 9 and the detection result (the voltage value of the charging voltage Vc) of the second voltage detection means. 4 is controlled. Control unit 11 executes a first charging process and a second charging process as control of charger 3 .

In the first charging process, the control unit 11 causes the charger 3 to start pre-charging, and performs self-diagnosis whether or not the output terminals T1 and T2 are open during the pre-charging period at predetermined intervals, Pre-charging is stopped when it is diagnosed that it is in an open state. Self-diagnosis is performed by comparing the voltage value of the output terminal voltage Vo with a predetermined threshold value (for example, 5% of the rated value of the charging voltage Vc).

In the second charging process, the controller 11 causes the charger 3 to perform main charging so that the charging voltage Vc becomes the predetermined voltage value V1. If the control unit 11 does not diagnose that it is in the open state within the pre-charging period, the second charging process (main charging) is performed without stopping the charging of the capacitor 1 .

For example, as shown in FIG. 2, when the output terminals T1 and T2 are open, the control unit 11 turns on the charger 3 at time t1 to start pre-charging the capacitor _1. When the charging voltage Vc of the capacitor 1 is Rise. In addition, since the charging voltage Vc leaks to the output terminals T1 and T2 via the first voltage equalizing resistor 6, the output terminal voltage Vo also rises.

The control unit 11 starts pre-charging of the capacitor 1, starts self-diagnosis, and compares the output terminal voltage Vo with a predetermined threshold value. _When the output end voltage Vo reaches the threshold value at time t2, the control unit 11 diagnoses that the output ends T1 and T2 are open, turns off the charger 3, and stops pre-charging of the capacitor 1. FIG. Thereby, it is possible to suppress the generation of high voltage at the output terminals T1 and T2.

As shown in FIG. 3, when the output terminals T1 and T2 are in a normal state (not in an open state), the controller 11 turns on the charger 3 to start pre-charging the capacitor ₁ at time t1. While the charging voltage Vc increases, the output terminal voltage Vo does not increase.

Therefore, the control unit 11 performs the _second charging process (main charging) at time t3 without diagnosing that the output terminals T1 and T2 are open during the pre _- charging period ₍ time t1 to time t3). to start. At this time, the control unit 11 shifts from the first charging process (pre-charging) to the second charging process (main charging) without stopping the charging of the capacitor 1 . Note that the ratio between the pre-charging period and the main charging period can be changed as appropriate.

At time t4, when control unit 11 turns off charger 3 and turns on semiconductor switch ₄ , the discharge current of capacitor 1 is connected to output terminals T1 and T2 via semiconductor switch 4 and protective reactor 5. supplied to an inductive load 200 .

As a result, according to the power supply device 100A according to the present embodiment, the control unit 11 causes the charger 3 to start pre-charging, performs self-diagnosis as to whether the output terminals T1 and T2 are open, and determines whether the output terminals T1 and T2 are open. Since the pre-charging is stopped when it is diagnosed as such, it is possible to suppress the generation of a high voltage at the output terminals T1 and T2 when the output terminals T1 and T2 are in the open state.

As a result, it is possible to avoid damage or failure of parts in the power supply device 100A due to high voltage, and excessive selection of parts becomes unnecessary. For example, a resistor with a smaller power capacity than the conventional one can be used as the second voltage equalizing resistor 14 .

In addition, since the power supply device 100A can suppress the generation of high voltage at the output terminals T1 and T2 as described above, the DC withstand voltage test of the output terminals T1 and T2 is unnecessary. The DC withstand voltage test is performed, for example, by continuously applying a DC voltage 1.4 times the rated voltage to the output terminals T1 and T2 for one minute. Eliminating the DC withstand voltage test eliminates the need to select components for the DC withstand voltage test, thereby reducing component costs.

In addition, since the power supply device 100A can detect an abnormality (that a high voltage is generated at the output terminals T1 and T2) before outputting the discharge current, failures and accidents due to poor withstand voltage of the inductive load 200 can be prevented. can be prevented.

Although the embodiments of the power supply device according to the present invention have been described above, the present invention is not limited to the above embodiments.

A power supply device according to the present invention comprises an output terminal, a capacitor, a charger for charging the capacitor, a semiconductor switch interposed in a discharge current path between the capacitor and the output terminal, and a second capacitor connected in parallel to the semiconductor switch. 1. The configuration can be changed as appropriate if it includes a voltage equalizing resistor, a detection means for detecting whether or not the output terminal is in an open state, and a control section for controlling the charger.

The control unit causes the charger to start pre-charging, performs self-diagnosis as to whether or not the output terminal is in an open state, and stops pre-charging when it is diagnosed as being in an open state. If the second charging process is executed to cause the charger to perform main charging when it is not diagnosed that the battery is in the open state in the diagnosis, the configuration can be changed as appropriate.

The control unit can be configured to perform a self-diagnosis as to whether or not the output terminal is in an open state even during the second charging process, and to stop main charging when it is diagnosed that the output terminal is in an open state.

It is preferable that the controller shifts from pre-charging to main charging without stopping the charging of the capacitor when the self-diagnosis does not determine that the capacitor is in an open state. , charging may be temporarily stopped.

Although the threshold in the self-diagnosis can be changed as appropriate, it is preferable to set the threshold to 10% or less of the rated value of the charging voltage Vc from the viewpoint of suppressing the parts cost.

100A power supply device 1 capacitor 2 charging resistor 3 charger 4 semiconductor switch 5 protection reactor 6 first voltage equalizing resistor 7 crowbar circuit 8 discharge circuit 9 first voltage detection means 10 second voltage detection means 11 control section 12 diode 13 resistor 14 2 equalizing resistor 15 switch 16 resistor 200 inductive load

Claims (4)

A power supply for supplying output current to an inductive load, comprising:
an output terminal to which the inductive load is connected;
a capacitor that outputs a discharge current as the output current;
a charger for charging the capacitor;
a semiconductor switch interposed in a discharge current path between the capacitor and the output terminal;
a first voltage equalizing resistor connected in parallel to the semiconductor switch;
a first voltage detection means for detecting an output terminal voltage generated at the output terminal;
a second voltage detection means for detecting the charging voltage of the capacitor;
a control unit for controlling the charger according to detection results of the first voltage detection means and the second voltage detection means ;
with
The control unit
By causing the charger to start pre-charging and comparing the output terminal voltage with a predetermined threshold value , self-diagnosis as to whether or not the output terminal is in an open state is performed. a first charging process for stopping pre-charging;
and a second charging process of causing the charger to perform main charging so that the charging voltage reaches a predetermined voltage value when the self-diagnosis does not determine that the battery is in an open state. and power supply. The control unit
2. The power supply device according to claim 1 , wherein when said self-diagnosis does not diagnose an open state, said pre-charging is shifted to said main charging without stopping charging of said capacitor. The semiconductor switch is composed of a plurality of thyristors connected in series,
3. The power supply device according to claim 1, wherein said first voltage equalizing resistor comprises a plurality of resistors connected in parallel to each of said plurality of thyristors. a protective reactor interposed in the discharge current path, having one end connected to the semiconductor switch and the other end connected to the high potential side of the output terminal;
A crowbar circuit provided between the semiconductor switch and the output terminal,
The crowbar circuit is
a series circuit consisting of a diode and a resistor;
a second voltage equalizing resistor connected in parallel to the diode;
with
A cathode side of the diode is connected to a connection point between the semiconductor switch and the protective reactor, and an anode side of the diode is connected to a low potential side of the output terminal via the resistor . The power supply device according to any one of claims 1 to 3 .

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