Method and system for adjusting internal inverter voltage of X-ray machine power supply

Abstract

The invention discloses an X-ray machine power supply internal inversion voltage adjusting method and system, and relates to the technical field of inversion voltage stabilization, and the method comprises the steps: carrying out the partition division of a PWM output frequency through setting different target voltages, and carrying out the switching control through a hysteretic curve; the numerical value of the feedback voltage is measured through a voltage divider, and adjustment and stabilization are carried out through a PID algorithm; voltage gears output by a set target are judged, and waveforms are output at different PWM frequencies; according to the invention, the contradictory relation between the internal inversion boost control precision of the X-ray machine power supply and the maximum power is solved, the influence of the PWM output frequency on the power and precision is considered, and the precision and high efficiency of the X-ray machine power supply are ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inverter voltage stabilization, in particular to an X-ray machine power supply inverter voltage stabilization method and system. BACKGROUND

[0002] The X-ray machine power supply needs to be boosted by inverter to obtain high-voltage output to drive the Q tube to emit X-rays. The voltage output by the power supply affects the accuracy of X-ray output, and also affects the power and efficiency.

[0003] By changing the inverter output waveform, the device design can be optimized, and the working efficiency and accuracy of the X-ray machine power supply can be improved. The PWM frequency is one of the key factors affecting the size of the ripple, and increasing the frequency can reduce the output ripple, thereby increasing the accuracy. However, increasing the frequency will increase the heat of the MOS tube in the inverter circuit, affecting the output power and efficiency.

[0004] In summary, optimizing the PWM wave output of the inverter power supply has important application value in improving device accuracy, increasing output power, and achieving energy saving and emission reduction.

[0005] For example, the existing patent with publication number CN102412726 discloses a full-bridge soft-switching medical X-ray machine high-voltage DC power supply, which includes a full-bridge inverter circuit, an LLC series resonant circuit, a high-frequency high-voltage transformer, a voltage doubler rectifier circuit, and a control module, which realizes high-voltage and high-power DC output. However, this design has a fixed frequency, and does not take into account the size of the output ripple under different target powers. Therefore, the present application provides an X-ray machine power supply internal inverter voltage regulation method and system. SUMMARY

[0006] The purpose of the present application is to provide an X-ray machine power supply internal inverter voltage regulation method and system to solve the problems raised in the background art.

[0007] To achieve the above purpose, the present application provides the following technical scheme: an X-ray machine power supply internal inverter voltage regulation method, comprising the following steps: S1, dividing the PWM output into multiple gears of different frequencies according to different set voltages; S2, using a hysteresis curve to determine the threshold voltage for jumping up or down the gear; S3, measuring the current actual voltage by a resistor voltage divider; S4, calculating the PID output value from the set voltage and the actual voltage by a PID regulator; S5, outputting PWM with different frequencies according to the current frequency gear and the PID output value.

[0008] The present application further improves that the specific steps of S1 include: S11, the power supply is divided into multiple voltage gears G1, G2, G3, G4 according to different set voltages V1, V2, V3,..., and multiple voltage thresholds V1, V2, V3,.... S12, multiple voltage gears are output by PWM with multiple frequencies f1, f2, f3, f4, respectively.

[0009] The further improvement of the application is that the specific step S2 comprises: S21, the hysteresis curve threshold is set as ±u, that is, when being lower than V1-u, V2-u, V3-u,..., the voltage gear G1, G2, G3 is jumped into, and when being higher than V1+u, V2+u, V3+u,..., the voltage gear G2, G3, G4 is jumped into.

[0010] The further improvement of the application is that the specific step S3 comprises: S31, the voltage is divided by using a resistor to obtain a divided voltage; S32, the actual voltage value is calculated by using an ADC to collect the divided voltage.

[0011] The further improvement of the application is that the specific step S4 comprises: S41, the set voltage su and the measured voltage pu are sent into a PID regulator; S42, the proportional error err is calculated according to err=Kp*(su-pu); S43, the error value err is accumulated, and the integral term item is obtained according to item=item+Ki*err; S44, the previous error is err_1, and the differential term dtem is calculated according to dtem=Kd*(err-err_1); S45, the proportional term err, the integral term item and the differential term dtem are added to obtain the final adjustment output.

[0012] The further improvement of the application is that the specific step S5 comprises: S51, according to the G1, G2, G3 gears of the current output voltage, the PID output value is converted into a PWM duty cycle output with the PWM frequencies f1, f2, f3, respectively.

[0013] In another aspect, the application provides an internal inverter voltage regulation system of an X-ray machine power supply, comprising: A partition gear shifting module is used to switch different gears according to a hysteresis curve by a set voltage; A voltage measurement module is used to collect a voltage value of a current high voltage output; A PID module is used to obtain a voltage adjustment by comparing the measured voltage value with the set voltage value. The PWM output module is used for outputting a PWM waveform with a corresponding frequency and duty cycle according to given parameters.

[0014] The further improvement of the application is that the partition shifting module comprises a partition unit and a hysteresis switching unit, the partition unit is used for generating a plurality of preset PWM frequency values, and the hysteresis switching unit is used for detecting a set voltage value and comparing the set voltage value with a threshold value.

[0015] The further improvement of the application is that the voltage measurement module comprises a resistance voltage dividing unit and an ADC acquisition unit, the resistance voltage dividing unit is used for dividing a high voltage to a voltage range that can be acquired by the ADC acquisition unit, and the ADC acquisition unit is used for acquiring the voltage after voltage division and sending the voltage to a processor.

[0016] The further improvement of the application is that the PID module comprises an error calculation unit, an integral calculation unit and a differential calculation unit, the error calculation unit is used for calculating a difference value between a current voltage and a target set voltage, the integral calculation unit is used for calculating an accumulated error value, and the differential calculation unit is used for calculating a difference between a current error value and a previous error value.

[0017] The further improvement of the application is that the PWM output module comprises a frequency generation unit and a duty cycle generation unit, the frequency generation unit is used for generating a waveform with a specified frequency according to a frequency gear, and the duty cycle generation unit is used for generating a specified duty cycle according to an output value of the PID module.

[0018] Compared with the prior art, the application has the following beneficial effects: The application firstly obtains different PWM output frequencies by dividing different voltage intervals, in a low voltage interval, due to the influence of a switching period, a higher PWM frequency can improve an output voltage ripple, thereby increasing the precision of an X-ray machine power supply, and in a high voltage interval, due to the influence of increased power and current, a lower PWM frequency can improve the heating degree of an inverter circuit MOS tube under the premise of ensuring output precision, thereby improving the efficiency of the X-ray machine. By setting a high-precision ADC measurement voltage and a PID calculation, negative feedback regulation is realized through a PID algorithm, thereby realizing fast and accurate voltage output regulation and ensuring the precision of the X-ray machine power supply. BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application, and are incorporated herein for purposes of explanation and are not intended to limit the application. In the drawings: Figure 1 The flowchart of the embodiment of the application; The flowchart of the embodiment of the application;Figure 2 is a schematic diagram of the method in the embodiment of the present application; Figure 3 is a framework diagram of the system in the embodiment of the present application. DETAILED DESCRIPTION

[0020] The technical solutions of the present application will be described in detail below with reference to the drawings and specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solutions of the present application, and are not limitations of the technical solutions of the present application. In the case of no conflict, the technical features in the embodiments of the present application and the embodiments can be combined with each other.

[0021] The term "and / or", only describes the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " generally represents that the associated objects before and after it are in an "or" relationship.

[0022] Embodiment 1 Figure 1 and Figure 2 The flowchart and schematic diagram of the internal inverter voltage regulation method of the power supply of the X-ray machine disclosed in the embodiment are respectively shown, and the steps are as follows: S1, the power supply is divided into three voltage gears G1, G2 and G3 according to different set voltages; S11, the power supply is divided into three gears G1, G2 and G3 according to different set voltages, and 50kV and 100kV are taken as voltage thresholds between the three gears; S12, the three voltage gears are respectively taken as three different frequencies of 32kHz, 25kHz and 20kHz as the frequency of PWM output.

[0023] S2, the threshold voltage of jumping up or down gear is determined by using a hysteresis curve, and the threshold value of the hysteresis curve is set to ±10kV; S21, when the current gear is G1, the target voltage su is set to jump into G2 gear when 60kV≤su<110kV, and to jump into G3 gear when u>110kV; S22, when the current gear is G2, the target voltage su is set to jump into G1 gear when su<40kV, and to jump into G3 gear when u>110kV; S23, when the current gear is G3, the target voltage su is set to jump into G1 gear when su<40kV, and to jump into G3 gear when 40kV≤u<90kV.

[0024] S3, the current actual voltage is measured by a resistance voltage divider; S31, using 5700MΩ and 570kΩ resistors for voltage division, to obtain a voltage division voltage in a ratio of 1:10000; S32, using an ADC to collect the voltage division voltage, and calculating the actual voltage value by multiplying 10000.

[0025] S4, calculating a PID output value by a PID regulator from a set voltage and an actual voltage; S41, sending the set voltage su and the measured voltage pu into the PID regulator; S42, calculating a proportional term error err according to err=Kp*(su-pu) with a proportional coefficient Kp; S43, calculating an integral term item according to item=item_1+Ki*err by successively accumulating the error value err with an integral coefficient Ki and a previous integral value item_1; S44, calculating a differential term dtem according to dtem=Kd*(err-err_1) with a differential coefficient Kd and a previous error err_1; S45, adding the proportional term err, the integral term item and the differential term dtem to obtain a final adjustment output.

[0026] S5, outputting a PWM corresponding to different frequencies according to a current frequency gear and the PID output value; S51, converting the PID output value into a PWM duty cycle output according to the G1, G2 and G3 gears of the current output voltage with a PWM frequency of 32kHz, 25kHz and 20kHz respectively.

[0027] In summary, the embodiment of the present application first divides the target voltage according to a hysteresis curve to obtain different corresponding PWM frequencies, so as to meet the accuracy and efficiency under different power requirements; and then calculates a PID result from the measured actual voltage and the target voltage to form a negative feedback regulation PWM output duty cycle, and combines the different PWM frequencies to output different corresponding PWM waves, so as to realize accurate and effective control of the output voltage.

[0028] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can be in the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the present application can be in the form of a computer program product implemented on one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

[0029] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 means for functionally implementing the steps in one or more flow or blocks

[0030] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 means for functionally implementing the steps in one or more flow or blocks

[0031] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 means for functionally implementing the steps in one or more flow or blocks

[0032] The embodiments of the present application described above are merely intended to illustrate the principles of the present application, and should not be taken in a limiting sense. Rather, they are merely intended to illustrate the principles of the present application. Various modifications of the above-described embodiments of the present application can be made by those skilled in the art without departing from the spirit and scope of the present application.

Claims

1. A method for regulating the internal inverter voltage of an X-ray generator power supply, characterized by: It comprises the following steps: S1, divide the PWM output into multiple positions with different frequencies according to different set voltages; S2, use a hysteresis curve to determine the threshold voltage for jumping up or down a position; S3, measure the current actual voltage through a resistance voltage dividing circuit; S4, calculate the PID output value from the set voltage and the actual voltage through a PID regulator; S5, output PWM with different frequencies according to the current frequency position and the PID output value.

2. The internal inverter voltage regulation method for an X-ray generator power supply according to claim 1, characterized in that: The specific steps of S1 include: S11, divide the power supply into multiple voltage positions G1, G2, G3, G4, etc. according to different set voltages with V1, V2, V3, etc. as multiple voltage thresholds; S12, output PWM with multiple frequencies f1, f2, f3, f4, etc. for the multiple voltage positions respectively.

3. The internal inverter voltage regulation method for an x-ray generator power supply according to claim 1, characterized in that: The specific steps of S2 include: S21, set the hysteresis curve threshold to ±u, i.e. jump into the G1, G2, G3, etc. voltage positions when below V1-u, V2-u, V3-u, etc., and jump into the G2, G3, G4, etc. voltage positions when above V1+u, V2+u, V3+u, etc.

4. The internal inverter voltage regulation method for an x-ray generator power supply according to claim 1, characterized by: The specific steps of S3 include: S31, use resistance to divide voltage and get a divided voltage; S32, use ADC to collect the divided voltage and calculate the actual voltage value.

5. The internal inverter voltage regulation method for an x-ray generator power supply according to claim 1, characterized by: The specific steps of S4 include: S41, send the set voltage su and the measured voltage pu into the PID regulator; S42, Kp is the proportional coefficient, calculate the proportional error err according to err=Kp*(su-pu); S43, the previous integral value is item_1 and Ki is the integral coefficient, accumulate the error value err successively, get the integral item item according to item=item_1+Ki*err, and record item_1 for next calculation; S44, the previous error is err_1 and Kd is the differential coefficient, calculate the differential item dtem according to dtem=Kd*(err-err_1), and record err_1 for next calculation; S45, add the proportional item err, the integral item item, and the differential item dtem to get the final adjustment output.

6. The internal inverter voltage regulation method for an x-ray generator power supply according to claim 1, wherein: The specific steps of S5 include: S51, according to the G1, G2, G3, etc. positions of the current output voltage, convert the PID output value to PWM duty cycle output with the PWM frequencies f1, f2, f3, etc. respectively.

7. An internal inverter voltage regulating system for an X-ray machine power supply, characterized in that: It comprises the following modules: Partition shifting software module; Voltage measurement hardware module; PID software module; PWM output software module.

8. The internal inverter voltage regulation system for an x-ray generator power supply of claim 7, wherein: The partition shifting module comprises a partition software unit and a hysteresis switching software unit.

9. The internal inverter voltage regulation system of the power supply of the X-ray machine according to claim 7, characterized in that: The voltage measurement hardware module comprises a resistance voltage dividing hardware unit and an ADC collection hardware unit.

10. The internal inverter voltage regulation system for an x-ray generator power supply of claim 7, wherein: The PID software module comprises a proportional calculation software unit, an integral calculation software unit, and a differential calculation software unit.

11. The internal inverter voltage regulation system for an x-ray generator power supply of claim 7, wherein: The PWM output software module comprises a frequency generation software unit and a duty cycle generation software unit.

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