WO2023115816A1

WO2023115816A1 - Analog and digital hybrid control-based high-voltage generator and control circuit and method therefor, and x-ray system

Info

Publication number: WO2023115816A1
Application number: PCT/CN2022/095454
Authority: WO
Inventors: 胡庆燚; 范声芳; 王万全; 陈飞
Original assignee: 苏州博思得电气有限公司
Priority date: 2021-12-24
Filing date: 2022-05-27
Publication date: 2023-06-29
Also published as: CN116390312A

Abstract

The present application relates to the field of X-rays, and specifically to an analog and digital hybrid control-based high-voltage generator and a control circuit and method therefor, and an X-ray system, comprising: a PID analog closed-loop control module, having the input end thereof connected to the output end of a feedback circuit and a reference voltage source, and used for outputting a frequency signal on the basis of error voltage between the voltage at the output end of a trimming circuit and reference voltage generated by the reference voltage source, the reference voltage being preset tube voltage of an X-ray tube; and a control unit, having the input end thereof connected to the output end of the PID analog closed-loop control module and the output end thereof connected to the input end of a driving circuit, and used for receiving the frequency signal output by the PID analog closed-loop control module, performing frequency division processing on the frequency signal, and outputting the frequency signal subjected to frequency division to the driving circuit. The heating problem of power devices such as an inverter is effectively avoided, damage of the high-voltage generator is reduced, and performance parameters of the high-voltage generator are maintained.

Description

High-voltage generator with analog and digital hybrid control, its control circuit, method and X-ray system

This application claims the priority of the Chinese patent application submitted to the China Patent Office on December 24, 2021, with the application number 202111598131.0, and the title of the invention is "Analog and Digital Hybrid Control High Voltage Generator Control Circuit and Method", the entire content of which is passed References are incorporated in this application.

technical field

The present application relates to the field of X-rays, in particular to an analog and digital hybrid controlled high-voltage generator, its control circuit, method and X-ray system.

Background technique

X-rays have important applications in the fields of disease diagnosis, non-destructive testing and security inspection. As the core component of X-ray generation, the high-voltage generator has very strict requirements on its performance parameters in practical applications, such as the output voltage rising edge time, high-voltage maximum power, exposure fluoroscopy duration, etc.

As shown in Figure 1, the output voltage of the high-voltage generator usually adopts a hardware simulation closed-loop method, and the closed-loop adjustment is realized by controlling the frequency of the drive circuit. However, during the exposure and fluoroscopy process using hardware simulation closed-loop, the inverter and other components will heat up severely, which may cause damage to the high-voltage generator.

Contents of the invention

Therefore, this application aims to solve the technical problem of serious heating of high-voltage generators in the prior art, thereby providing an analog-digital hybrid control high-voltage generator control circuit, including a drive circuit, an inverter and a trimming circuit connected in series in sequence, The output end of the trimming circuit is used to connect with the X-ray tube, the output end of the trimming circuit is connected with a feedback circuit, and the feedback circuit is used to collect and feed back the voltage at the output end of the trimming circuit; it also includes:

A PID analog closed-loop control module, the input end of the PID analog closed-loop control module is connected to the output end of the feedback circuit and the reference voltage source, and is used for between the voltage at the output end of the trimming circuit and the reference voltage generated by the reference voltage source The error voltage of the output frequency signal; wherein, the reference voltage is the tube voltage of the preset X-ray tube;

A control unit, the input end of the control unit is connected to the output end of the PID analog closed-loop control module, the output end of the control unit is connected to the input end of the drive circuit, and is used to receive the PID analog closed-loop control module The frequency signal is output, and the frequency signal is subjected to frequency division processing, and the frequency signal after frequency division is output to the driving circuit.

Optionally, the control unit includes a central processing unit, the input end of the central processing unit is connected to the output end of the PID analog closed-loop control module, the output end of the central processing unit is connected to the input end of the driving circuit connect.

Optionally, the control unit includes a micro-control unit, the input of the micro-control unit is connected to the output of the PID analog closed-loop control module, the output of the micro-control unit is connected to the input of the drive circuit connect.

Optionally, the trimming circuit includes a boost circuit and a rectifier circuit, the output terminal of the boost circuit is connected to the input terminal of the rectifier circuit, the boost circuit is connected to the inverter, and the rectifier circuit The output end of the circuit is connected with the feedback circuit, and the output end of the rectification circuit is used for connecting with the X-ray tube.

The present application also provides a high-voltage generator control method with analog and digital hybrid control, which is used to control the above-mentioned high-voltage generator control circuit. The method includes:

The PID analog closed-loop control module receives the reference voltage and the voltage at the output end of the trimming circuit, and outputs a frequency signal to the control unit based on the error voltage between the reference voltage and the voltage at the output end of the trimming circuit; wherein the reference voltage is generated by a reference voltage source , and is the tube voltage of the preset X-ray tube;

The control unit divides the frequency signal to obtain a divided frequency signal, and outputs the divided frequency signal to the driving circuit.

Optionally, before the control unit divides the frequency signal to obtain a frequency-divided frequency signal, and outputs the frequency-divided frequency signal to the drive circuit, it further includes:

Obtaining a reference voltage and a reference current; wherein, the reference current is a preset tube current of the X-ray tube.

Optionally, the control unit divides the frequency signal to obtain a divided frequency signal, and outputs the divided frequency signal to the drive circuit, including:

The control unit calculates a reference power based on the reference voltage and reference current;

When the reference power is less than or equal to the preset power, the control unit performs frequency division processing on the frequency signal to obtain a frequency signal after frequency division, and outputs the frequency signal after frequency division to the drive circuit.

Optionally, the method further includes: when the reference power is greater than a preset power, the control unit outputs the frequency signal to the driving circuit.

The present application also provides a high-voltage generator with analog and digital hybrid control, including the above-mentioned high-voltage generator control circuit, the high-voltage generator has a placement station, and the high-voltage generator control circuit is located on the placement station .

The present application also provides an X-ray system, which is characterized in that it includes: an X-ray tube;

Like the high-voltage generator controlled by analog and digital hybrid control above, the output end of the high-voltage generator is connected to the X-ray tube.

The technical solution of the present application has the following advantages:

The high-voltage generator control circuit with analog and digital hybrid control provided by this application, the frequency signal output by the PID analog closed-loop control module is used as the input of the control unit, which effectively improves the adjustment period of the digital closed-loop and shortens the stable period of the closed-loop control. The control unit divides the frequency signal output by the PID analog closed-loop control module to reduce the frequency input to the drive circuit, thereby effectively avoiding the heating problem of power devices such as inverters, reducing damage to the high-voltage generator, and maintaining the high-voltage generator. performance parameters.

Description of drawings

In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the specific embodiments or prior art. Obviously, the accompanying drawings in the following description The figures show some implementations of the present application, and those skilled in the art can obtain other figures based on these figures without any creative effort.

Fig. 1 is the structural representation of the high voltage generator control circuit in the prior art;

Fig. 2 is the structural representation of the control circuit of the high-voltage generator of Embodiment 1 of the present application;

Fig. 3 is the structural representation of trimming circuit in Fig. 2;

Fig. 4 is the flow chart of the control method of the high voltage generator of embodiment 2 of the present application;

Fig. 5 is the flowchart of step S102 in Fig. 4;

Fig. 6 is a schematic structural view of the high-voltage generator in Example 3 of the present application;

FIG. 7 is a schematic diagram of the X-ray structure in Example 3 of the present application.

Detailed ways

The technical solutions of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are some of the embodiments of the present application, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

In the description of the present application, it should be noted that the terms "first", "second", and "third" are used for description purposes only, and should not be understood as indicating or implying relative importance. In addition, the technical features involved in the different embodiments of the present application described below may be combined as long as they do not constitute a conflict with each other.

X-ray inspection is widely used in various industries, such as disease detection, non-destructive testing and security inspection. As the core component of X-ray generation, the high-voltage generator has extremely high requirements on its performance parameters in practical applications. The high-voltage generator mainly adopts the hardware simulation closed-loop method to realize the closed-loop regulation. As shown in Figure 1, the existing high-voltage generator control circuit includes a PID analog closed-loop control module 101, a drive circuit 102, an inverter 103, a trimming circuit 105 and a feedback circuit 105, and the input terminal and the feedback circuit of the PID analog closed-loop control module 101 105 is connected to a reference voltage source (not shown), and the PID analog closed-loop control module 101 generates a frequency signal based on the reference voltage output by the reference voltage source and the output voltage of the trimming circuit 105 fed back by the feedback circuit 105 to the drive circuit 102.

The hardware simulation closed-loop adjustment method has obvious advantages in dynamic response. The rise time of the tube voltage of the X-ray tube is relatively short. However, during exposure, fluoroscopy, etc., components such as the inverter will heat up severely, which may cause damage to the high-voltage generator.

Example 1

This embodiment provides a high-voltage generator control circuit with analog and digital hybrid control, as shown in Figure 2, including a PID analog closed-loop control module 101, a drive circuit 102, an inverter 103, a trimming circuit 104, a feedback circuit 105 and control unit 106 . Wherein, the drive circuit 102, the inverter 103 and the trimming circuit 104 are connected in series in sequence, the output end of the trimming circuit 104 can be connected with an X-ray tube (not shown), and the trimming circuit 104 outputs a high-voltage direct current to promote X-ray The tube emits X-rays. The output end of the trimming circuit 104 is connected to the input end of the feedback circuit 105, the input end of the PID analog closed-loop control module 101 is connected to the output end of the feedback circuit 105, and the feedback circuit 105 collects the trimming The voltage at the output terminal of the circuit 104 is fed back to the PID analog closed-loop control module 101 . It should be noted that, the voltage output by the trimming circuit 104 needs to reach a reference voltage, and the reference voltage is a preset tube voltage of the X-ray tube, that is, the voltage at both ends of the X-ray tube reaches the reference voltage before it can The X-ray tube is caused to generate X-rays.

The output terminal of the control unit 106 is connected to the drive circuit 102 , and the input terminal of the control unit 106 is connected to the output terminal of the PID analog closed-loop control module 101 . By using the frequency signal output by the PID analog closed-loop control module 101 (analog closed-loop) as the input signal of the control unit 106 (digital closed-loop), the adjustment period of the control unit 106 is effectively improved, and the closed-loop control stabilization period is shortened. The input terminal of the PID analog closed-loop control module 101 is also connected to a reference voltage source (not shown), and the reference voltage source generates a reference voltage input to the PID analog closed-loop control module 101, and the PID analog closed-loop control module 101 According to the reference voltage generated by the reference voltage source and the voltage at the output end of the trimming circuit 104 fed back by the feedback circuit 105 , a frequency signal is output to the control unit 106 . That is, the PID analog closed-loop control module 101 uses PID closed-loop control to generate the corresponding frequency signal and outputs it to the control unit 106 according to the voltage difference between the reference voltage and the voltage at the output terminal of the trimming circuit 104 . It should be noted that, the value of the reference voltage generated by the reference voltage source is equal to the value of the preset tube voltage of the X-ray tube.

After the control unit 106 receives the frequency signal output by the PID analog closed-loop control module 101, it can choose to perform frequency division processing on the frequency signal, divide the frequency signal into multiple low-frequency frequency signals, and then The low-frequency frequency signal is output to the driving circuit 102, which effectively reduces the operating frequency of the driving circuit 102, and avoids the heating problem of power devices such as the inverter 103 and the trimming circuit 104 under high frequency.

To sum up, the frequency signal output by the PID analog closed-loop control module 101 is used as the input signal of the control unit 106, which effectively improves the adjustment period of the digital closed-loop and shortens the stable period of the closed-loop control. The control unit 106 performs frequency division processing on the frequency signal output by the PID analog closed-loop control module 101 to reduce the frequency input to the drive circuit 102, thereby effectively avoiding power devices such as the inverter 103 The heating problem reduces the damage of the high voltage generator and maintains the performance of the high voltage generator.

In one embodiment, the control unit 106 includes a central processing unit (central processing unit, CPU) or a micro control unit (Microcontroller Unit, MCU). In the case that the control unit 106 includes a central processing unit, the input end of the central processing unit is connected to the output end of the PID analog closed-loop control module 101, and the output end of the central processing unit is connected to the input of the driving circuit 102. The terminals are connected, and the central processing unit is used to perform N times of frequency division processing on the frequency signal, so as to reduce the operating frequency of the driving circuit 102 .

In another embodiment, the control unit 106 includes a micro-control unit, the input of the micro-control unit is connected to the output of the PID analog closed-loop control module 101, and the output of the micro-control unit is connected to the The input end of the driving circuit 102 is connected, and the micro-control unit is used to perform N times of frequency division processing on the frequency signal, so as to reduce the operating frequency of the driving circuit 102 .

In yet another embodiment, as shown in FIG. 3 , the trimming circuit 104 includes a boost circuit 1041 and a rectifier circuit 1042, the output terminal of the boost circuit 1041 is connected to the input terminal of the rectifier circuit 1042, and the boost circuit 1041 is connected to the input terminal of the rectifier circuit 1042. The input end of the circuit 1041 is connected to the output end of the inverter 103, the output end of the rectification circuit 1042 is connected to the input end of the feedback circuit 105, and the output end of the rectification circuit 1042 is used to connect with the X-ray tube. The drive circuit 102 amplifies the frequency signal after receiving the frequency signal sent by the control unit 106 . The driving circuit 102 sends the amplified frequency signal to the inverter 103, so that the inverter 103 is turned on or off, and the inverter 103 converts direct current into alternating current. 103 sends the alternating current to the booster circuit 1041, and the booster circuit 1041 processes the alternating current, raises the voltage of the alternating current, and passes the raised alternating current to the rectification circuit 1042, and the rectification The circuit 1042 converts the AC power into a DC output.

The feedback circuit 105 collects the voltage output by the rectification circuit 1042 and feeds back the output voltage to the PID analog closed-loop control module 101 . The voltage output from the output terminal of the rectification circuit 1042 is output to the X-ray tube, and when the voltage output by the rectification circuit 1042 reaches a reference voltage, the X-ray tube generates X-rays. It should be noted that there may be an error between the voltage output by the rectification circuit 1042 and the reference voltage, but the error is within an acceptable range. That is, there is a small error between the tube voltage of the X-ray tube and the tube current of the X-ray tube and the preset tube voltage (reference voltage) and preset tube current (reference current).

In one or more embodiments, the PID analog closed-loop control module 101 includes a negative feedback module 1011 and an analog circuit 1012, the output of the negative feedback module 1011 is connected to the input of the analog circuit 1012, and the negative The positive pole of the feedback module 1011 is connected to the reference voltage source, and the negative pole of the negative feedback module 1011 is connected to the output terminal of the feedback circuit 105 for calculating the voltage at the output terminal of the rectification circuit 1042 and the voltage generated by the reference voltage source. The error voltage between the reference voltages, the analog circuit 1012 adopts PID closed-loop control to generate a corresponding frequency signal according to the error voltage.

This embodiment provides a high-voltage generator control circuit with analog and digital mixed control, which can simultaneously realize two adjustment modes of analog closed-loop and digital closed-loop. Compared with the existing circuit combining the two adjustment modes, it can reduce the volume.

Example 2

This embodiment provides a high-voltage generator control method with analog and digital hybrid control. FIG. 4 illustrates the control of the high-voltage generator control circuit with analog and digital hybrid control provided in Embodiment 1 according to some embodiments of the present application. flow chart. Although the processes described below include operations in a particular order, it should be clearly understood that the processes may also include more or fewer operations, which may be performed sequentially or in parallel. As shown in Fig. 4, the high voltage generator control method at least includes the following steps.

S101. The PID analog closed-loop control module receives a reference voltage and a voltage at the output end of the trimming circuit, and outputs a frequency signal to the control unit based on an error voltage between the reference voltage and the voltage at the output end of the trimming circuit.

As shown in Figure 2, a reference voltage source (not shown) generates the reference voltage and outputs it to the PID analog closed-loop control module 101, wherein the value of the reference voltage generated by the reference voltage source is normal to that of the X-ray tube The value of the voltage required for operation is the same. The feedback circuit 105 collects the voltage at the output end of the trimming circuit 104 and feeds it back to the PID analog closed-loop control module 101, and the PID analog closed-loop control module 101 receives the reference voltage and the voltage at the output end of the trimming circuit 104, According to the error voltage between the reference voltage and the voltage at the output terminal of the trimming circuit 104 , PID closed-loop control is used to generate a corresponding frequency signal and output it to the control unit.

S102. The control unit divides the frequency signal to obtain a divided frequency signal, and outputs the divided frequency signal to the driving circuit.

As shown in Figure 2, the control unit 106 receives the frequency signal output by the PID analog closed-loop control module 101, can perform frequency division processing on the frequency signal, and output the frequency signal after the frequency division processing to the A driving circuit 102, the driving circuit 102 amplifies the input low-frequency frequency signal, outputs the amplified frequency signal to the inverter 103 for subsequent processing, and finally outputs a voltage to drive the X-ray tube. The control unit 106 performs frequency division processing on the frequency signal, which can reduce the operating frequency of the drive circuit 102, thereby effectively avoiding the heating problem of the power devices such as the inverter 103, reducing damage to the high voltage generator, and maintaining high voltage Generator performance parameters.

In one or more embodiments, before step S102, the method further includes: acquiring a reference voltage and a reference current. Wherein, the reference voltage is a preset tube voltage of the X-ray tube, and the reference current is a preset tube current of the X-ray tube. The control unit calculates a reference power based on the reference voltage and the reference current. Wherein, the reference power is the product of the reference voltage and the reference current. As shown in FIG. 5, step S102 includes the following steps (S201-S203).

S201. Comparing the reference power and the preset power.

The preset power is the power preset by the system, and the host computer can be used to set the preset power, reference voltage (unit: kV) and reference current (unit: mA). The preset power is a power threshold for switching between analog and digital hybrid control. If the reference power is less than or equal to the preset power, perform step S202; if the reference power is greater than the preset power, perform step S203.

S202. The control unit performs frequency division processing on the frequency signal to obtain a frequency signal after frequency division, and outputs the frequency signal after frequency division to the driving circuit. S203. The control unit outputs the frequency signal to the driving circuit. According to exposure and perspective conditions, it is compatible with analog closed-loop and digital closed-loop working modes.

Example 3

This embodiment provides an analog and digital hybrid controlled high voltage generator, the high voltage generator has the analog and digital hybrid controlled high voltage generator control circuit of any one of the preceding embodiments. As one of the implementations, as shown in Figure 6, the high-voltage generator 201 has a placement station (not shown), and the analog and digital hybrid control high-voltage generator control circuit provided in Embodiment 1 is set at the placement station superior. When the high-voltage generator 201 is running, the high-voltage generator control circuit using the analog-digital hybrid control implements the analog-digital hybrid control high-voltage generator control method provided in Embodiment 2.

This embodiment also provides an X-ray system, as shown in Figure 6 and Figure 7, comprising a high-voltage generator 201 and an X-ray tube 202, the X-ray tube 202 has an anode 2021 and a cathode 2022, and the high-voltage generator The output end of 201 (that is, the output end of the rectifier circuit in Embodiment 1) is connected to the anode 2021 and cathode 2022 of the X-ray tube to drive the X-ray tube 202 to generate X-rays.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. However, the obvious changes or changes derived therefrom are still within the protection scope of the invention of the present application.

Claims

A high-voltage generator control circuit with analog and digital hybrid control, including a driving circuit, an inverter and a trimming circuit connected in series in sequence, the output end of the trimming circuit is used to connect with an X-ray tube, and the output end of the trimming circuit A feedback circuit is connected, and the feedback circuit is used to collect and feed back the voltage at the output end of the trimming circuit; it is characterized in that it also includes:

PID analog closed-loop control module, the input end of the PID analog closed-loop control module is connected with the output end of the feedback circuit and the reference voltage source, and is used for the difference between the voltage at the output end of the trimming circuit and the reference voltage generated by the reference voltage source Between the error voltage, the output frequency signal; wherein, the reference voltage is the tube voltage of the preset X-ray tube;

A control unit, the input end of the control unit is connected to the output end of the PID analog closed-loop control module, the output end of the control unit is connected to the input end of the drive circuit, and is used to receive the PID analog closed-loop control module The frequency signal is output, and the frequency signal is subjected to frequency division processing, and the frequency signal after frequency division is output to the driving circuit.
The high voltage generator control circuit according to claim 1, wherein the control unit comprises a central processing unit, the input end of the central processing unit is connected to the output end of the PID analog closed-loop control module, and the central processing unit The output terminal of the processor is connected with the input terminal of the driving circuit.
The high-voltage generator control circuit according to claim 1, wherein the control unit includes a micro-control unit, the input of the micro-control unit is connected to the output of the PID analog closed-loop control module, and the micro-control unit The output terminal of the control unit is connected with the input terminal of the driving circuit.
The high-voltage generator control circuit according to any one of claims 1-3, wherein the trimming circuit includes a boost circuit and a rectifier circuit, and the output terminal of the boost circuit is connected to the input terminal of the rectifier circuit , the input end of the boost circuit is connected to the output end of the inverter, the output end of the rectification circuit is connected to the input end of the feedback circuit, and the output end of the rectification circuit is used to communicate with the X Tube connection.
A high-voltage generator control method with analog and digital hybrid control, used to control the high-voltage generator control circuit described in any one of claims 1-4, characterized in that the method includes:

The PID analog closed-loop control module receives the reference voltage and the voltage at the output end of the trimming circuit, and outputs a frequency signal to the control unit based on the error voltage between the reference voltage and the voltage at the output end of the trimming circuit; wherein the reference voltage is Generated by the reference voltage source and is the preset tube voltage of the X-ray tube;

The control unit divides the frequency signal to obtain a divided frequency signal, and outputs the divided frequency signal to the driving circuit.
The high voltage generator control method according to claim 5, wherein the frequency signal is divided by the control unit to obtain a frequency signal after frequency division, and the frequency signal after frequency division is output to Before the drive circuit, it also includes:

Obtaining a reference voltage and a reference current; wherein, the reference current is a preset tube current of the X-ray tube.
The control method of the high-voltage generator according to claim 6, wherein the control unit performs frequency division processing on the frequency signal to obtain a frequency signal after frequency division, and outputs the frequency signal after frequency division to the drive circuit, including:

The control unit calculates a reference power based on the reference voltage and reference current;

When the reference power is less than or equal to the preset power, the control unit performs frequency division processing on the frequency signal to obtain a frequency signal after frequency division, and outputs the frequency signal after frequency division to the the drive circuit.
The high voltage generator control method according to claim 7, characterized in that the method further comprises:

When the reference power is greater than a preset power, the control unit outputs the frequency signal to the driving circuit.
An analog-digital hybrid controlled high-voltage generator, characterized in that it comprises the high-voltage generator control circuit described in any one of claims 1-4.
An X-ray system, characterized in that it comprises:

X-ray tube;

The high-voltage generator with analog and digital hybrid control according to claim 9, the output end of the high-voltage generator is connected with the X-ray tube.