JPH0750200A - Inverter type x-ray high voltage device - Google Patents

Abstract

PURPOSE:To prevent the drop of the inverter output voltage and further the X-ray tube voltage, and to eliminate the flicker of radioscopy image by feeding the excessive charge stored in a smoothing capacitor of a converter (rectifier circuit) to an alternating current power source for regeneration at the time of switching the operation of an inverter type X-ray high voltage device from the photographing operation to the radioscopy operation. CONSTITUTION:An alternating current reactors 51-53 are connected between alternating current power sources U, V, W and a converter 1. Self-arc- extinguishing switching elements 10-15 are connected between the alternating current reactors and a positive and a negative sides of the converter direct current output, and diodes 20-25 are connected to these switching elements in reversed-parallel with each other to form a converter 1. Charge of a smoothing capacitor 6 for smoothing the output voltage of the converter can be fed for regeneration to the alternating current power source at the time of radioscopy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention converts an alternating current power source into direct current, converts this direct current into high frequency alternating current using an inverter, boosts its output voltage and rectifies it to generate a high direct current voltage. The present invention relates to an inverter type X-ray high voltage device that applies this to an X-ray tube to generate X-rays.

[0002]

2. Description of the Related Art Conventionally, an inverter type X-ray high voltage apparatus of this type has a commercial three-phase AC power source U, V, as shown in FIG.
An AC voltage from W is converted into a DC voltage by a three-phase full-wave rectifier circuit (hereinafter referred to as a converter) 1 ′ composed of thyristors 40 to 45, which is smoothed by a smoothing capacitor 6 and input to the inverter 2. The inverter 2 controls the phase difference and frequency of the inverter 2 by utilizing the resonance phenomenon between the resonance capacitor 7 and the leakage inductance, stray capacitance, etc. of the high-voltage transformer 5, so that the X-ray tube 4, which is a load, is controlled. A tube voltage is applied. That is, the AC voltage output from the inverter 2 is stepped up by the high-voltage transformer 5, converted into high-voltage DC by the high-voltage rectifier circuit 3, and converted into the X-ray tube 4.
Was being applied to.

Voltage applied to the X-ray tube 4 (tube voltage)
Are controlled as follows. First, converter 1
The control circuit (converter control circuit) 31 ′ of the converter 1 ′ of the converter 1 ′ is determined according to the target values S 5 and S 7 of the tube voltage and the target values S 6 and S 8 of the current (tube current) flowing through the X-ray tube 4. Target value S3 of output voltage (converter output voltage) and voltage of smoothing capacitor 6 (actual converter output voltage)
The gates of the thyristors 40 to 45 are controlled by the converter control signal S1 obtained from S4. The inverter 2 has
The converter output voltage (DC voltage) S4 obtained by being controlled by the converter control signal S1 is applied.

The control circuit (inverter control circuit) 32 of the inverter 2 has an actual tube voltage Vr and a tube voltage target value S5.
The inverter 2 is controlled by the inverter control signal S2 obtained from the phase difference obtained from S7 and the target value kVr of the tube voltage having the frequency. In the X-ray tube 4, a voltage (tube voltage) obtained by boosting the AC voltage from the inverter 2 thus controlled by the high-voltage transformer 5 and converting it by the high-voltage rectifier circuit 3.
Vr is applied. The tube current is controlled by adjusting the temperature of the filament of the X-ray tube 4 by a filament heating circuit (not shown).

Such an inverter type X-ray high-voltage device generally emits X-rays to a subject and transmits them through X-rays.
Both X-ray photography that captures X-rays on X-ray film (hereinafter simply referred to as radiography) and X-ray fluoroscopy (hereinafter simply referred to as fluoroscopy) that captures transmitted X-rays with an X-ray TV camera and observes them on a TV monitor. Applied to. Of these, in shooting, X
A sufficient X-ray dose is used for imprinting a high-quality image on the X-ray film, and a small X-ray dose is used for fluoroscopy so that continuous irradiation of X-rays does not harm the subject. In particular, the tube current has a large difference of 100 mA to 1000 mA at the time of photographing and 0.5 mA to 4 mA at the time of see-through.

Next, the operation of the above-mentioned conventional apparatus at the time of actual photographing or fluoroscopy will be described. First, the operator gives the target values S5 and S7 of the respective tube voltages and the target values S6 and S8 of the respective tube currents to the control target value determination circuit 33 'for photographing or fluoroscopy from an operating device (not shown). Next, the operator inputs either the imaging command signal R or the fluoroscopic command signal F to the control target value determination circuit 33 'in order to command the timing of imaging or fluoroscopy from the operating device.

As a result, the control target value determination circuit 33 'is
Target values S5 and S7 of the tube voltage depending on whether the image is taken or fluoroscopy.
And the target values S6 and S8 of the tube current, the converter 1
The target value S3 of the output voltage (converter output voltage) of 'to the converter control circuit 31', and the target value kV of the tube voltage
The r is input to the inverter control circuit 32.

The converter control circuit 31 'controls the thyristors 40 to 45 with a converter control signal S1 to its gate so that the target value S3 of the converter output voltage and the actual converter output voltage S4 match. Similarly, the inverter control circuit 32 controls the target value k of the tube voltage.
The switching elements 16 to 19 of the inverter 2 are controlled by the inverter control signal S2 so that Vr and the actual tube voltage Vr match, and a desired tube voltage is obtained.

[0009]

In the above-mentioned conventional apparatus, when the fluoroscopic mode and the radiographic mode are frequently switched and used, a drop in the tube voltage may occur and the fluoroscopic image observed on the television monitor may flicker. Hereinafter, this problem will be described in detail.

First, a method of controlling the tube voltage by changing the phase difference of inverter control will be described. FIG. 4 is a time chart showing the principle of controlling the output voltage of the inverter 2 by the phase difference of the inverter control signal S2. Each of the switching elements 16 to 19 of the inverter 2 in FIG. 3 delays the switching element 19 by a phase difference φ1 with respect to the switching element 16 as shown in FIGS. The switching element 18 is turned on and off by delaying the phase difference φ1. Further, the upper and lower switching elements, that is, the switching elements 16 and 17, and the switching elements 18 and 19
And turn on and off with a 90 ° phase shift.

At this time, a resonance current flows through the capacitor 7 connected to the output side of the inverter 2 and the leakage inductance of the high-voltage transformer 5, and each switching element 16-19.
And the currents flowing in the diodes 26 to 29 connected in anti-parallel are as shown by the solid lines in FIGS. 4 (e) to (h), respectively, and the output voltage of the inverter 2 is shown by the solid lines in FIG. 3 (j). Then, the output currents are shown by the solid lines in (i).

FIG. 5 shows the phase difference φ and the tube voltage Vr at this time.
Shows the relationship. As can be seen from FIG. 5, the smaller the phase difference φ is, the higher the tube voltage is output, and the phase difference φ is 1
The output becomes zero at 80 °. Further, the output voltage is different even when the tube current is large as in the case of photographing and when the tube current is small as in the case of fluoroscopy, even with the same phase difference φ. Further, in FIG. 5, the characteristics when the converter output voltage is low are shown by the solid line, and when the tube voltage is high, by the thin line. That is, curve a shows the characteristics when the converter output voltage is high at the time of see-through (small tube current), curve b shows the characteristics when the converter output voltage is low at the time of see-through (small tube current), and curve c shows the time when shooting ( Curve D shows the characteristics when the converter output voltage is high, and curve D shows the characteristics when the converter output voltage is low at the time of shooting (tube current is large).

Thus, a desired tube voltage can be obtained by changing the phase difference φ and the converter output voltage. For example, to obtain a certain value of tube voltage during fluoroscopy,
The converter output voltage may be lowered to have a phase difference of φ1, and the converter output voltage may be increased to have a phase difference of φ2 (φ2> φ1).

Next, returning to FIG. 4, the switching element 16 of the inverter 2 depends on the magnitude of the converter output voltage.
It will be explained that the current and voltage waveforms of ~ 19 are different. Figure 4
In, the thin line indicates the current or voltage of each part when the converter output voltage is high. When the converter output voltage is high, the phase difference is set to φ2, which is larger than φ1, and the overlapping of the switching elements 16 and 19 or the switching elements 17 and 18 is reduced, and the output voltage of the inverter 2 is set to the thin line in (j). By doing so, a desired tube voltage Vr is obtained as a result.

However, at this time, the currents shown by the thin lines in (e) to (h) flow through the switching elements 16 to 19 constituting the inverter 2. This is because not only the current for turning off the switching elements 16 and 17 and the turning on current for the switching elements 18 and 19 is large, but also the peak value of the current is large, so that the switching element 16 has a lower output voltage.
Loss and electromagnetic noise generated in the inverters 19 to 19 and the high voltage transformer 5 are extremely large.

Especially in the case of see-through, it is required to continuously output X-rays for about several seconds to several tens of minutes, and the device generates heat or is generated due to the loss generated in the inverter 2 or the high voltage transformer 5. There is a problem that electromagnetic noise has a bad influence on the fluoroscopic image on the TV monitor.

Therefore, in order to reduce the loss and noise generated in the inverter 2, the converter output voltage is appropriately adjusted according to the tube voltage and the tube current so that the phase difference φ is as small as possible and the output current of the inverter is as shown in FIG. As shown by the solid line in (i), it was necessary to optimize so as to smoothly change. That is, since the tube current is large in photography, the converter output voltage is set high, and in fluoroscopy, the converter output voltage is set low because the tube current is small.

FIG. 6 is a time chart for explaining the phenomenon in which the tube voltage drops and the fluoroscopic image flickers in such a conventional apparatus. In X-ray image diagnosis of a circulatory organ such as a digestive tract or a blood vessel, imaging and fluoroscopy may be alternately repeated as shown in FIGS. 6 (a) and 6 (b). Therefore, in order to minimize the loss and the electromagnetic noise as described above, the target value S3 of the converter output voltage is set as shown in FIG.
As shown in (c), it is changed according to the photographing command signal R and the fluoroscopic command signal F. However, in the conventional device of FIG. 3, the thyristors 40 to 45 constitute the converter 1 ′, and since the thyristors 40 to 45 cannot flow a current in the opposite direction in principle, the smoothing capacitor 6 is once charged. Charge is
It cannot be discharged unless output from the inverter 2 to the X-ray tube 4 side.

Therefore, the converter output voltage S4 cannot be lowered until the fluoroscopy is started even after the photographing is completed, and even when the fluoroscopy is started, the tube current is very small in the fluoroscopy, so that the converter output voltage S4 is reduced. It cannot be lowered at high speed (see FIG. 6 (d)).

The delay (e) of the voltage drop causes a response delay in the converter control circuit 31 ', and causes a drop (f) of the converter output voltage immediately after the actual fluoroscopy is started. If this dip (f) is large, the converter output voltage at that time becomes equal to or lower than the minimum converter output voltage required to obtain the desired tube voltage, and the tube voltage is sufficient even if the phase difference of the inverter 2 is zero. Is not obtained, and FIG. 6 (f)
As shown in, the tube voltage drops (g). This drop (g) appears as annoying flickering of the fluoroscopic image on the TV monitor, and significantly impedes medical image diagnosis.

An object of the present invention is to regenerate the electric charge accumulated in the smoothing capacitor to the AC power source side and to promptly lower the converter output voltage, thereby minimizing the loss of the inverter and the generation of electromagnetic noise. , No drop in voltage can always obtain a good tube voltage waveform,
That is, it is to provide an inverter type X-ray high voltage device which does not cause flicker in a monitor image.

[0022]

The above object is to provide a converter that receives an AC power source and rectifies it, a smoothing capacitor that smoothes the output voltage of this converter, and an inverter that converts the output of this smoothing capacitor into high-frequency AC. A high-voltage transformer that boosts the output voltage of the inverter; a high-voltage rectifier circuit that rectifies the output of the high-voltage transformer; and an X-ray that generates an X-ray when the output voltage of the high-voltage rectifier circuit is applied. In an inverter type X-ray high voltage apparatus comprising a line tube and an inverter control circuit for controlling the inverter so that a target tube voltage is input and the actual tube voltage is matched, a fluoroscopic command signal and an imaging command signal A desired command signal among them is input, and a control target value determination circuit that determines a target output voltage and a target tube voltage of the converter according to the input command signal, The converter control circuit that controls the converter so that the output voltage of the converter and the target output voltage match, and an AC reactor inserted between the AC power supply and the converter, the converter, Self-extinguishing switching elements respectively connected in the forward direction between the AC reactor and the converter positive-side output terminal and between the AC reactor and the converter negative-side output terminal, and reverse to these switching elements, respectively. It is achieved by comprising a diode connected in parallel.

[0023]

[Action] An AC reactor is connected between the AC power supply and the converter, and a switching element capable of self-extinguishing is connected between each of the AC reactor and the positive and negative sides of the converter DC output. Not only can the desired converter output voltage be obtained by configuring the converter by connecting diodes in antiparallel, respectively,
When looking through, the extra charge of the smoothing capacitor can be regenerated to the AC power supply side.

As a result, a drop in the converter output voltage that occurs when switching from photographing to fluoroscopy is suppressed, a good tube voltage waveform is always obtained, and flicker does not occur in the monitor image.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing an embodiment of an inverter type X-ray high voltage device according to the present invention. In this FIG.
Reference numerals 51 to 53 are AC reactors inserted in the respective phases of the three-phase AC power supplies U, V, W, 1 is connected to the AC reactors 51 to 53, and the AC voltage from the AC power supplies U, V, W is converted into a desired DC voltage. A converter for conversion, 6 is connected to the output end of the converter 1, a smoothing capacitor for smoothing the converter output voltage, 2 is connected an input end to the smoothing capacitor 6,
It is an inverter that converts the DC voltage charged in it into high-frequency AC.

Reference numeral 7 is a resonance capacitor inserted in one side of the output end of the inverter 2. The resonance capacitor 7 is for generating a resonance current with the leakage inductance of the high-voltage transformer 5 connected to the output end of the inverter 2 via the resonance capacitor 7. 3 is a high voltage rectifier circuit for rectifying the output voltage of the high voltage transformer 5,
4 is applied with the high DC voltage obtained by the high voltage rectifier circuit 3 and X
It is an X-ray tube that generates rays.

Reference numeral 33 designates a photographing command signal R and a fluoroscopic command signal F from an operating device (not shown), and target values S5, S7; S6, S of the tube voltage and the tube current for photographing and fluoroscopy, respectively.
8 is an input, and is a control target value determination circuit that outputs a target value S3 of the converter output voltage and a target value kVr of the tube voltage. The converter output voltage target value S3 is input to the converter 31 from the control target value determination circuit 33.
The converter control circuit outputs the converter control signal S1 for turning on and off the switching element of the converter 1 described later by comparing the output voltage S4 with the output voltage S4. 32, the target value kVr of the tube voltage is input from the control target value determination circuit 33, and the switching element of the inverter 2 described later is turned on so that the target value kVr matches the tube voltage Vr.
It is an inverter control circuit that outputs an inverter control signal S2 that is turned off.

Here, the converter 1 includes switching elements 10, 12, 1 which are respectively connected in the forward direction between the AC reactors 51 to 53 and the converter positive side output terminals.
4, and switching elements 11, 13 and 15 (which are capable of self-extinguishing) respectively connected in the forward direction between the AC reactors 51 to 53 and the converter negative side output end, and these switching elements 10 to 15. Each of the diodes 20 to 25 is connected in antiparallel.

The inverter 2 includes switching elements 16 and 18 respectively connected between the positive output terminal of the converter 1 and the output terminal of the inverter 2, the negative output terminal of the converter 1 and the output terminal of the inverter 2. And switching elements 17 and 19 respectively connected between the switching elements 16 and 19 and diodes 26 to 29 respectively connected in antiparallel to these switching elements 16 to 19.

In the above configuration, the AC voltage input from the AC power supplies U, V, W is input to the converter 1 via the reactors 51 to 53 inserted in each phase. At this time, the reactors 51 to 53 are the switching elements 10 to 1
The change in the potentials of the connection points R, S, T in FIG. 1 caused by the turning on and off of 5 smoothes the current input to the converter 1 from the AC power supplies U, V, W and, as a result, changes the converter output voltage. AC power supply U, V, W
It works to raise the voltage more than the peak value of AC voltage.

The converter 1 receives commercial AC voltage from the AC power supplies U, V, W, rectifies the AC voltage according to the operation of the converter 1 described later, and stores electric charges in the smoothing capacitor 6 as a DC voltage. The inverter 2 converts this DC voltage into a high-frequency AC voltage and generates a resonance current by the resonance capacitor 7 and the leakage inductance of the high-voltage transformer 5, whereby the secondary winding of the high-voltage transformer 5 is generated. A high frequency high voltage is applied to the connected high voltage rectifier circuit 3. The high-voltage rectifier circuit 3 rectifies this, converts it into a high-voltage DC voltage, and inputs it to the X-ray tube 4. As a result, X-rays are emitted from the X-ray tube 4.

Next, the operation of the converter 1 will be described in detail. Since the switching elements 10 to 15 of the converter 1 are respectively connected to the anti-parallel diodes 20 to 25, the diodes 20 to 25 form a full-wave rectification circuit, and the smoothing capacitor 6 has AC power sources U, V, and The voltage near the peak voltage of W is charged from the beginning.

Further, only one of the upper and lower switching elements 10, 11; 12, 13; 14, 15 of the converter 1 is always turned on, and is turned on at a frequency sufficiently higher than the frequencies of the AC power supplies U, V, W. Repeat off. For example, one of the switching element 10 on the upper side and the switching element 11 on the lower side is always turned on and the other is turned off.

At this time, if the period during which the switching element 11 is on is longer than the period during which the switching element 10 is on, the average potential of the connection point R is close to the negative potential of the smoothing capacitor 6, and the AC power source A large amount of current flows into the converter 1 from the U phase of U, V, W via the reactor 51. On the other hand, if the ON period of the switching element 10 is longer than the ON period of the switching element 11, the average potential of the connection point R is close to the positive side potential of the smoothing capacitor 6, and the AC power supply U from the converter 1 via the reactor 51. ，
The current starts to flow into the U phase of V and W. By thus controlling the switching elements 10 to 15 of the converter 1 to be turned on and off, the current flowing through the AC reactors 51 to 53 can be controlled.

When the phase voltages of the AC power supplies U, V, W and the currents of the AC reactors 51 to 53 are synchronized in this way, the power input to the converter 1 can be adjusted. As a result, the converter output voltage S4, that is, the voltage across the smoothing capacitor 6 can be controlled.

Similarly, the DC converter output voltage is turned on and off by turning on and off the switching element switches 10 to 15 of the converter 1.
It is also possible to regenerate the AC power sources U, V, W via 53. In this case, the converter 1 operates as a DC / AC converter as an inverter.

FIG. 2 is a time chart for explaining the operation and effect of the device of the present invention.

As shown in FIGS. 2A and 2B,
The photographing command signal R and the fluoroscopic command signal F are alternately turned on, and in response thereto, the control target value determination circuit 33 outputs the target value S3 of the converter output voltage and the target value kVr of the tube voltage ((c), (See (e)). The target value S3 of the converter output voltage in FIG. 2 (c) gives a higher voltage during imaging with a large tube current than in fluoroscopy with a small tube current, and as described with reference to FIG. The current changes smoothly, and the switching elements 16 to 19 of the inverter 2
It is decided to suppress the loss and electromagnetic noise generated in.

At this time, as described above, in FIG. 1, the converter 1 transfers the electric charge of the smoothing capacitor 6 to the AC power source U,
Since it has a function of regenerating to the V and W sides, the rectified voltage can be promptly dropped without supplying electric power from the inverter 2 to the X-ray tube 4 side (see (h) in FIG. 2D). .

Therefore, the response delay in the converter control circuit 31 as described with reference to FIG. 6 in the conventional device is reduced, and the converter output voltage does not drop after the fluoroscopy is started (FIG. 2 (d)). (See (i)). Therefore, there is no voltage drop in the tube voltage of FIG. 2 (f) (see (e) in FIG. 2 (f)), and a good tube voltage waveform can be obtained.

As a result, the flicker of the fluoroscopic image when switching from radiography to fluoroscopy, which has been a problem with conventional devices, is eliminated, and image information suitable for medical diagnosis can be obtained.

The converter 1 in the device of the present invention
In the above, even if all the switching elements 10 to 15 are turned off, the diodes 20 to 25 form a full-wave rectifier circuit, and an output voltage is generated up to the peak value of the AC voltage of the AC power supplies U, V, and W. Therefore, the operation of converter 1 basically controls the converter output voltage by boosting. In this respect, the output voltage characteristic is different from the conventional device shown in FIG.
Therefore, in the device of the present invention, the winding ratio of the high-voltage transformer 5 can be reduced as much as the voltage can be increased by the converter 1, and the output current of the inverter 2 can be further reduced. In this respect as well, the switching elements 16 to 19
The loss occurring in the high voltage transformer 5 can be suppressed, and as a result, the phase difference can be reduced to allow a smooth current to flow, and resonance loss and electromagnetic noise can be effectively reduced.

In the above embodiment, a three-phase AC power supply was used as an example of the AC power supply, but a single-phase AC power supply may be used. In this case, the switching element of the converter 1 and the anti-parallel diode group are four groups. Become.

Further, in FIG. 1, the switching elements 10 to 1 are
Although IGBTs (insulated gate bipolar transistors) 5 and 16 to 19 are shown, the invention is not limited to this, and bipolar transistors, MOSFETs, GTOs, MCTs, etc.
Any switching element can be used as long as it is a self-extinguishing switching element.

Further, the resonance capacitor 7 is not always required. The output circuit of the inverter 2 is a series resonance type as shown in the figure (a system in which a resonance capacitor and an inductance are connected in series to cause resonance).
Alternatively, a method of utilizing the resonance due to the leakage inductance of the high voltage transformer 5 and the capacity of the winding may be used, regardless of the configuration of the output side circuit of the inverter 2.

Furthermore, in the above embodiment, the inverter 2 controls the tube voltage by controlling the phase difference, but the invention is not limited to this, and the frequency and the switching element 16 of the inverter 2 are controlled.
Alternatively, a method of changing the on-periods of 19 to 19 may be used. Further, the reactors 51 to 53 are connected to the respective phases of the AC power supplies U, V and W.
Although the case where only the converter is inserted is shown as an example, another reactor or capacitor may be inserted so that the switching noise of the converter 1 is not returned to the AC power supplies U, V, W side.

[0047]

As described above, according to the present invention, not only can resonance loss and electromagnetic noise be reduced by suppressing the loss generated in the switching element of the inverter and the high voltage transformer, but also the charge of the smoothing capacitor can be changed to AC. It can be regenerated to the power supply side, which allows the converter output voltage to drop quickly, and the converter output voltage drop that occurs when switching from imaging to fluoroscopy can be suppressed, and a good tube voltage waveform can always be obtained. Therefore, there is an effect that flicker does not occur in the monitor image.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the device of the present invention.

FIG. 2 is a time chart for explaining the operation and effect of the same device.

FIG. 3 is a circuit diagram of a conventional device.

FIG. 4 is a time chart showing the principle of controlling the output voltage of the inverter by the phase difference of the inverter control signal in the inverter type X-ray high voltage device.

FIG. 5 is a graph showing a relationship between a phase difference of the same inverter and a tube voltage.

FIG. 6 is a time chart for explaining problems of the conventional device.

[Explanation of symbols]

 U, V, W 3-phase AC power supply 1, 1'converter 2 inverter 3 high-voltage rectifier circuit 4 X-ray tube 5 high-voltage transformer 6 smoothing capacitor 7 resonance capacitor 10-19 switching element 20-29 diode 31, 31 ' Converter control circuit 32 Inverter control circuit 33, 33 'Control target value determination circuit 40-45 Thyristor 51-53 AC reactor

Claims (1)

[Claims] 1. A converter for receiving an AC power supply and rectifying the AC power supply, a smoothing capacitor for smoothing an output voltage of the converter, an inverter for converting an output of the smoothing capacitor into a high frequency AC, and an output voltage of the inverter. A high-voltage transformer for boosting, a high-voltage rectifier circuit for rectifying the output of this high-voltage transformer, an X-ray tube to which the output voltage of this high-voltage rectifier circuit is applied to generate X-rays, and a target tube voltage are In an inverter type X-ray high voltage apparatus comprising an inverter control circuit for controlling the inverter so that the input tube voltage and the actual tube voltage match, a desired command signal of a fluoroscopic command signal and an imaging command signal is input. And a control target value determination circuit that determines a target output voltage and a target tube voltage of the converter according to the input command signal, and an output voltage of the converter. A converter control circuit that controls the converter so that the standard output voltage is matched, and an AC reactor that is connected between the AC power supply and the converter are provided, and the converter is the AC reactor and the converter positive. Switching elements connected in the forward direction between the AC output and the side output terminal, and between the AC reactor and the converter negative output terminal, and diodes respectively connected in anti-parallel with these switching elements. An inverter type X-ray high-voltage device comprising: