JP7043352B2 - Power supply and rotating anode X-ray tube device - Google Patents

Description

Embodiments of the present invention relate to a power supply device and a rotating anode X-ray tube device.

In a motor connected to an inverter of a three-phase AC power supply, as a method of determining whether or not there is a phase loss in the output current from the inverter to the motor, a current transformer is conventionally provided on the output side of the inverter and the output of the current transformer is used. Information was received by the inverter control device, and the presence or absence of phase loss was determined.

Japanese Unexamined Patent Publication No. 10-233184

On the other hand, it has been desired to determine the presence or absence of phase loss without using a current transformer.

An embodiment of the present invention provides a power supply device and a rotating anode X-ray tube device capable of determining the presence or absence of phase loss without using a current transformer.

One embodiment includes a three-phase AC power supply, an inverter connected to the three-phase AC power supply, and an inverter control device connected to the inverter to control the output of the inverter, and is driven by an output current from the inverter. The inverter has an output current detection unit that detects the current of each phase output to the motor, and the inverter control device receives a detection value signal of the output current detection unit. Therefore, it is a power supply device having a phase loss determination unit for determining a phase loss from the detected value signal.
Further, one embodiment is a rotary anode wire tube device including a rotary anode X-ray tube and the power supply device for driving the motor of the rotary anode X-ray tube.

FIG. 1 is a block diagram showing a configuration of a power supply device according to an embodiment. FIG. 2 is a flowchart showing a motor type determination process. FIG. 3 is a flowchart showing a phase loss determination flow. FIG. 4 is a graph showing the relationship between the output current value and the threshold value in the phase loss determination flow. FIG. 5 is a schematic configuration diagram of a rotating anode X-ray tube device according to an embodiment.

Hereinafter, the rotary anode X-ray tube apparatus according to the embodiment will be described in detail with reference to the drawings. In addition, in order to clarify the description, the drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the actual embodiment, but this is merely an example, and the present invention is provided. It does not limit the interpretation. Further, in the present specification and each figure, the same reference reference numerals may be given to the components exhibiting the same or similar functions as those described above with respect to the above-mentioned figures, and the overlapping detailed description may be omitted as appropriate. ..

First, the rotary anode X-ray tube device 1 according to the embodiment will be described with reference to FIGS. 1 to 5.
As shown in FIG. 5, the rotating anode X-ray tube device 1 includes a rotating anode X-ray tube 2 and a power supply device 21.
As shown in a schematic cross section in FIG. 5, the rotating anode X-ray tube 2 includes a vacuum enclosure 3, a rotating anode structure 5 housed in the vacuum enclosure 3, a fixed shaft 7, and a cathode 9. It is provided with a stator coil 11 provided on the outside of the vacuum enclosure 3.
The inside of the vacuum enclosure 3 is held in a vacuum.

The rotating anode structure 5 includes an anode target 12, an anode target support 13, and a drive rotor 15.
The anode target 12 has an umbrella-like appearance, and an anode target layer 12a is formed on the outer surface thereof.
The anode target support 13 has a bottomed cylindrical shape, and the anode target 12 is fixed to the bottom 13a side.
A drive rotor 15 is fixed to the outer peripheral portion of the cylindrical anode target support 13.

The cathode 9 is attached inside the vacuum enclosure 3 towards the anode target layer 12a and includes a filament 17 as an electron emitting source to emit electrons.
The fixed shaft 7 is arranged via a bearing 14 provided inside the anode target support 13 and the drive rotor 15, and rotatably supports the rotary anode structure 5.
A current is supplied to the stator coil 11 from a power supply device 21 described later, and the rotating anode structure 5 rotates together with the drive rotor 15 due to the electromagnetic force generated in the stator coil 11. In the present embodiment, the motor 19 is composed of the stator coil 11 and the drive rotor 15.

Next, the power supply device 21 will be described.
As shown in FIG. 1, the power supply device 21 includes a commercial AC power supply 23, an inverter 25, and an inverter control device 27.
The commercial AC power supply 23 is a 200 V (volt) three-phase AC power supply.
The inverter 25 is provided with input terminals R, S, and T on the input side connected to the commercial AC power supply 23, and is connected to each of the three phases by the input terminals R, S, and T. A noise filter (not shown) is provided between the commercial AC power supply 23 and the inverter 25.
The output terminals U, V, and W of each phase of the inverter 25 are connected to the terminals 1, 2, and 3 of the stator coil (motor) 11.

The inverter 25 includes an output conversion unit 29, an output current detection unit 31, and a current signal output unit 33. The output conversion unit 29 receives the control signal from the inverter control device 27 and converts the current output from the inverter into a predetermined voltage and current value.
The output current detection unit 31 detects the current of each phase output from each output terminal U, V, W. For example, the current value (ampere) of each phase is constantly detected, and the detected current value is the current. It is converted into a signal by the signal output unit 33 and transmitted to the inverter control device 27.

The inverter control device 27 is a microcomputer (microcomputer), which controls the drive of the inverter 25 and determines the open phase of the output current of the inverter. The inverter control device 27 includes a drive program storage unit 35, a type-specific data storage unit 37, a type determination unit 39, a comparison unit 41, a phase loss determination unit 43, and a timer 45.
A predetermined program for controlling the output current of the inverter 25 is stored in the drive program storage unit 35. For example, the control program of the inverter 25 that operates the rotary anode X-ray tube 2 during the initial operation, the normal operation, the type determination program, and the like is stored.
In the type determination program, for example, the output current of the inverter 25 is output at three-phase 200V for E seconds, then at 100V for F seconds, and then at 120V for G seconds. E seconds is, for example, 1 second, F is 0.5 seconds, and G is 10 seconds, but these values are arbitrary and are not limited.

The type-specific data storage unit 37 stores current data such as a current waveform and a maximum current value when the rotary anode X-ray tube 2 of each type is driven by the type determination program stored in the drive program storage unit 35. There is. That is, the current data output from the inverter 25 is different for each type of rotating anode X-ray tube 2, and the current data of each type of rotating anode X-ray tube 2 is obtained in advance by an experiment, and the data storage unit for each type is obtained. It is stored in 37. In this embodiment, the current data of the three types of rotating anode X-ray tubes 2 are stored. The three types of rotary anode X-ray tubes 2 are type 1, type 2, and type 3, respectively.

As shown in FIG. 4, in type 1, the maximum current value I ₀ of each phase when output from the inverter 25 at 200 V is, for example, 1 A, and the maximum current value I ₀ of type 2 is 0, 9 A. , The maximum current value I ₀ of the type 3 is 0, 8A. Further, the threshold value K of the current value stored in advance is, for example, 0.9A for type 1, 0.8A for type 2, and 0.7A for type 3.

The type determination unit 39 matches the current data such as the current waveform or the maximum current value I ₀ of any of the above-mentioned corresponding rotating anode X-ray tubes 2 as compared with the current data stored in the type-specific data storage unit 37. It is determined whether or not to do so, and any of the above-mentioned type 1, type 2, and type 3 is determined. The current data determined by the type determination unit 39 compares, for example, only the maximum current value I ₀ of each phase or only the voltage V (volt) when the inverter 25 outputs 200 V for E seconds and then outputs 100 V for F seconds. You may.

In the comparison unit 41, the current value I detected by the output current detection unit 31 when the current is output from the inverter 25 to the motor 19 during normal drive operation is changed to the type of the rotary anode X-ray tube 2 determined by the type determination unit 39. It is compared whether it is less than or equal to the threshold value K set accordingly or less than the threshold value K. In this embodiment, it is compared whether or not the current value I is equal to or less than the threshold value K.
The open phase determination unit 43 determines whether or not the current value I compared by the comparison unit 41 described above is equal to or less than the threshold value within the time set by the timer 45 for each of the three phases. Then, when the current value I does not exceed the threshold value K within the set time, that is, when the current value I is always equal to or less than the threshold value K within the set time, it is determined that the phase is open.

Next, the flow of phase loss determination in the power supply device 21 will be described. First, the type determination of the rotating anode X-ray tube 2 and the setting of the threshold value will be described with reference to FIG.
As shown in FIG. 2, after the start, the type determination program stored in the drive program storage unit 35 is executed in step S1. The type determination program is executed by outputting to the inverter 25 connected to the rotating anode X-ray tube 2 at three-phase 200V for E seconds, then outputting at 100V for F seconds, and then outputting at 120V for G seconds.

In step S2, the output current detection unit 31 of the inverter 25 detects the current value I of each phase, and outputs the detected current value I to the inverter control device 27 via the current signal output unit 33 (see FIG. 1). ). The type determination unit 39 of the inverter control device 27 compares with the current data for each type stored in the data storage unit 37 for each type.
Specifically, from the comparison between the detected current value I and the current data for each type, it is determined in step 3 whether or not it is type 1, and if it is not type 1, it is determined in step S4 whether or not it is type 2. If it is not 2, it is determined in step S5 whether or not it is type 3, the threshold value K of each type determined in step S6 is determined, and the process ends. As described above, the threshold value K is preset for each type.
If it does not belong to any of the types, the inverter control device 27 cannot determine the type, and the threshold value K is not set.

Next, the phase loss determination flow will be described with reference to FIG.
After the start, the timer is set in step S21. The timer sets, for example, 360 degrees in electrical angle, that is, one cycle of frequency. The setting of the timer may be 180 degrees or 480 degrees in terms of electric angle, and is not particularly limited to 360 degrees as long as it is 180 degrees or more.
Next, in step S22, the output current detection unit 31 of the inverter 25 detects the current value I, and in step S23, the detection is continuously performed for a certain period of time until a predetermined time elapses. The current value I is detected for each of the U, V, and W phases.

In step S24, whether or not the current value I detected by the comparison unit 41 is equal to or less than the threshold value K is compared, and in the phase absence determination unit 43, the current value I of the predetermined phase continues to be equal to or less than the threshold value K within a predetermined time. In other words, if the current value I has never exceeded the threshold value K within a predetermined time, it is determined that the phase is open, a phase open flag is set in the predetermined phase in step S25, and the phase open flag is set in step S26. The inverter control device 27 transmits a drive stop signal to the inverter 25 to stop the drive of the inverter 25.

On the other hand, if the detection current I exceeds the threshold value K within a predetermined time in step S24, the timer 45 is reset in step S21 and steps 23 to 24 are repeated to detect the current until the predetermined time elapses. It is determined whether or not the value I is equal to or less than the threshold value.
As described above, in the phase openness determination flow in steps S21 to 26, the current value I output to the stator coil 11 is constantly and continuously monitored by the output current of the inverter 25, and whether or not the threshold value K is exceeded is determined by the three phases. Monitor each phase.

According to the present embodiment, as shown in FIGS. 1 and 3, the inverter 25 has a current detection unit 31 for detecting the current I of each phase output to the stator coil (motor) 11, and is an inverter control device. Since the phase loss determination unit 43 determines the phase loss by the current I, the phase 27 can determine the presence or absence of the phase loss in the power supply device 21 without using a conventional current transformer. Further, since an expensive current transformer is not used for the determination of the open phase, the manufacturing cost can be reduced and the erroneous determination due to the failure of the current transformer can be prevented.

Since the current detected by the current detection unit 31 has a current value I, it is easy to detect.
As shown in steps S21 to 24 of FIG. 3, the output current detection unit 31 constantly detects the current while the inverter 25 is being driven, and the phase loss determination unit 43 constantly receives the detection value signal from the output current detection unit 31. Since the open phase is determined, the open phase can be monitored at all times.
Since the phase loss determination unit 43 sets the threshold value K and determines whether or not the current value I is equal to or less than the threshold value K, the configuration is simple and the phase absence determination can be easily performed.
The inverter control device 27 stores the current data for each type of the rotating anode X-ray tube (motor) in the data storage unit 37 for each type, and sets a threshold K according to the type for each type of the rotating anode X-ray tube. Therefore, it is possible to prevent erroneous detection caused by different types of rotating anode X-ray tubes (motors).

One embodiment described above is presented as an example and is not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

For example, in the embodiment, the stator coil 11 of the rotating anode X-ray tube 2 has been described as an example as a motor, but the present invention is not limited to this, and any motor driven by a three-phase AC current may be another type of motor. May be.
The output current detection unit 31 detects not only the current value I but also the voltage V of each phase, and the phase loss determination unit 43 detects whether or not the detected voltage V exceeds a set threshold value. May be.

1 ... Rotating anode X-ray tube device, 2 ... Rotating anode X-ray tube, 11 ... Stator coil (motor),
19 ... Motor, 21 ... Power supply device, 21 ... Power supply device, 25 ... Inverter, 27 ... Inverter control device, 31 ... Output current detection unit, 35 ... Drive program storage unit, 37 ... Type-specific data storage unit, 39 ... Type determination Unit, 41 ... Comparison unit, 43 ... Phase loss determination unit, 45 ... Timer.

Claims (3)

Three-phase AC power supply and
With the inverter connected to the three-phase AC power supply,
A power supply device including an inverter control device connected to the inverter and controlling the output of the inverter, and driving a motor by an output current from the inverter.
The inverter has an output current detection unit that detects the current value of the current of each phase output to the motor.
The inverter control device receives a detection value signal of the output current detection unit, determines a phase absence determination unit from the detected value signal , and type-specific data storing current data for each type of a plurality of motors. Has a storage unit and
The open phase determination unit sets a threshold value, and determines that the phase is open when the current value is always below the threshold value or smaller than the threshold value within a predetermined time.
The inverter control device specifies the type of the motor by comparing the detected value signal received from the inverter with the current data of the data storage unit for each type before the phase loss determination unit determines, and the threshold value is specified. A power supply that is a threshold set for each type of motor . The first aspect of the present invention, wherein the output current detection unit constantly detects a current while the inverter is being driven, and the phase absence determination unit constantly receives the detection value signal from the current detection unit to determine the phase absence. Power supply . The motor is a rotary anode X-ray tube motor, and is a rotary anode X-ray tube device including the rotary anode X-ray tube and the power supply device according to claim 1 or 2 .

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