X-ray tube rotating anode control device

Abstract

The application provides an X-ray bulb rotating anode control device, which comprises a control console, a control unit, a drive circuit unit, a single-phase full-bridge inverter unit, an alternating current rectifier unit, an overcurrent detection unit and a motor; the output end of the control console is connected with the input end of the control unit, the output end of the control unit is connected with the first input end of the drive circuit unit; the output end of the drive circuit unit is connected with the first input end of the single-phase full-bridge inverter unit, the first output end of the single-phase full-bridge inverter unit is connected with the motor; the output end of the alternating current rectifier unit is connected with the second input end of the single-phase full-bridge inverter unit, the second output end of the single-phase full-bridge inverter unit is connected with the overcurrent detection unit; and the output end of the overcurrent detection unit is connected with the second input end of the drive circuit unit. Through the cooperative work of the control console, the control unit and the drive circuit, the device realizes real-time and accurate regulation and control of the rotating anode rotating speed, and meets the dynamic rotating speed switching under different inspection requirements.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a rotating anode control device for an X-ray tube. Background Technology

[0002] In the fields of medical imaging and industrial inspection, X-ray tubes are key components for acquiring high-quality images, and the operating status of their rotating anodes directly affects the performance of the tubes.

[0003] With the development of medical technology, medical X-ray machines are widely used in various medical institutions, leading to increasingly higher requirements for X-ray tubes. The demand for high-power X-ray tubes continues to grow. Low-speed tubes typically rotate at around 3000 rpm, while high-power, high-speed rotating anode X-ray tubes need to reach 10000 rpm to meet heat dissipation requirements. However, current technology struggles to flexibly switch between different rotation speeds and cannot adequately adapt to tubes of varying power.

[0004] Traditional X-ray tube rotating anode control methods have many problems. On the one hand, the control circuit cannot automatically adjust the anode rotation speed according to the tube model and operating power, resulting in uneven heating of the anode target surface and shortening the tube's service life. On the other hand, there is a lack of effective overcurrent detection and protection mechanisms, which can easily damage the tube and related circuit components when abnormal current occurs.

[0005] Therefore, developing an X-ray tube rotating anode control device that can flexibly switch rotation speeds and effectively protect the circuit has become an urgent problem to be solved. Utility Model Content

[0006] In view of the aforementioned problems, this application is made to provide an X-ray tube rotating anode control device that overcomes or at least partially solves the aforementioned problems, comprising a control console, a control unit, a drive circuit unit, a single-phase full-bridge inverter unit, an AC rectifier unit, an overcurrent detection unit, and a motor;

[0007] The output terminal of the control console is connected to the input terminal of the control unit, and the output terminal of the control unit is connected to the first input terminal of the drive circuit unit; the output terminal of the drive circuit unit is connected to the first input terminal of the single-phase full-bridge inverter unit, and the first output terminal of the single-phase full-bridge inverter unit is connected to the motor; the output terminal of the AC rectifier unit is connected to the second input terminal of the single-phase full-bridge inverter unit, and the second output terminal of the single-phase full-bridge inverter unit is connected to the overcurrent detection unit; the output terminal of the overcurrent detection unit is connected to the second input terminal of the drive circuit unit.

[0008] Optionally, the driving circuit unit includes an inverter and an optocoupler; the input terminal of the inverter is connected to the output terminal of the control unit; and the output terminal of the inverter is connected to the input terminal of the optocoupler.

[0009] Optionally, the single-phase full-bridge inverter unit includes four insulated-gate bipolar transistors; the gate of each insulated-gate bipolar transistor is connected to a protection diode; and the gate of each insulated-gate bipolar transistor is also connected to a gate capacitor discharge control circuit.

[0010] Optionally, the four insulated-gate bipolar transistors (IGBTs) are respectively a first IGBT, a second IGBT, a third IGBT, and a fourth IGBT; wherein the first and third IGBTs form the upper bridge arm, and the second and fourth IGBTs form the lower bridge arm; the collectors of the first and third IGBTs are connected to the positive terminal of the DC power supply, and the emitters of the second and fourth IGBTs are connected to the negative terminal of the DC power supply; the emitter of the first IGBT and the collector of the second IGBT are connected at a connection point designated as point 1, and the emitter of the third IGBT and the collector of the fourth IGBT are connected at a connection point designated as point 2; the motor is connected between points 1 and 2; the gate of each IGBT is connected to the drive circuit unit.

[0011] Optionally, the control unit includes an MCU, which is connected to the console via an RS232 interface; the output of the RS232 interface is connected to an interface protection circuit.

[0012] Optionally, the MCU is also connected to an external clock circuit, a power-on reset circuit, and a voltage divider sampling circuit.

[0013] Optionally, the input terminal of the rectifier unit is connected to a three-phase 380V AC power supply.

[0014] Optionally, the overcurrent detection unit includes two current sensor chips, which are used to detect the startup current and the inverter operating current, respectively; the overcurrent detection unit also includes a comparator and an OR gate circuit; when an overcurrent is detected, a fault signal is output to the control unit, and the control unit interrupts the drive signal output to protect the device.

[0015] Optionally, the single-phase full-bridge inverter unit is equipped with a temperature sensor, which is connected to the control unit.

[0016] Optionally, the motor is an X-ray tube rotating anode motor; the control device outputs pulses of different widths according to the X-ray tube model selected by the control console to drive the corresponding X-ray tube rotating anode motor to start in high-speed or low-speed mode.

[0017] This application has the following advantages:

[0018] In the embodiments of this application, addressing the problem that existing X-ray tube rotating anode control methods are difficult to flexibly switch between different rotation speeds and cannot well adapt to X-ray tubes of different power, this application proposes an X-ray tube rotating anode control device, including a control console, a control unit, a drive circuit unit, a single-phase full-bridge inverter unit, an AC rectifier unit, an overcurrent detection unit, and a motor; the output terminal of the control console is connected to the input terminal of the control unit, and the output terminal of the control unit is connected to the first input terminal of the drive circuit unit; the output terminal of the drive circuit unit is connected to the first input terminal of the single-phase full-bridge inverter unit, and the first output terminal of the single-phase full-bridge inverter unit is connected to the motor; the output terminal of the AC rectifier unit is connected to the second input terminal of the single-phase full-bridge inverter unit, and the second output terminal of the single-phase full-bridge inverter unit is connected to the overcurrent detection unit; the output terminal of the overcurrent detection unit is connected to the second input terminal of the drive circuit unit. This device achieves real-time and precise control of the rotating anode speed through the coordinated operation of the control console, control unit, and drive circuit, meeting dynamic speed switching requirements under different inspection needs (e.g., continuously adjustable from 3000-10000 rpm), completely solving the adaptability problem of traditional fixed speed solutions. It employs an optimized combination of an AC rectifier unit and a single-phase full-bridge inverter unit to achieve highly efficient power conversion (conversion efficiency improved by more than 15%), while simultaneously reducing system heat generation and energy consumption. Attached Figure Description

[0019] To more clearly illustrate the technical solution of this application, the drawings used in the description of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This invention provides a schematic diagram of the overall structure of an X-ray tube rotating anode control device.

[0021] Figure 2 A schematic diagram of the PC software console of an X-ray tube rotating anode control device provided in this application is shown;

[0022] Figure 3 This invention provides a schematic diagram of the MCU control circuit of an X-ray tube rotating anode control device.

[0023] Figure 4 This application provides a schematic diagram of the drive circuit for a rotating anode control device for an X-ray tube.

[0024] Figure 5 The diagram shows the drive waveform of an X-ray tube rotating anode control device provided in this application;

[0025] Figure 6 A schematic diagram of the integrated structure of the circuit units of an X-ray tube rotating anode control device provided in this application is shown. Detailed Implementation

[0026] To make the objectives, features, and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0027] The inventors discovered through analysis of existing technology that:

[0028] ① Existing rotating anode control systems mostly use a fixed frequency drive method, which cannot adjust the speed in real time according to the working status of the X-ray tube, resulting in energy waste during low-power applications and insufficient heat dissipation during high-power applications;

[0029] ② Traditional open-loop control schemes lack a speed feedback mechanism, and cannot automatically compensate for speed fluctuations when the load changes (such as bearing wear or insufficient lubrication), resulting in uneven temperature distribution on the target surface;

[0030] ③ The mainstream protection circuits on the market only have simple fuse protection functions, and the response speed is slow (>100ms), which cannot effectively suppress the damage of sudden overcurrent to expensive X-ray tube components;

[0031] ④ Different models of X-ray tubes require customized dedicated drive circuits, resulting in poor equipment compatibility and high upgrade and maintenance costs for hospitals.

[0032] Please refer to Figure 1 The diagram illustrates the structure of a rotating anode control device for an X-ray tube provided in this application.

[0033] Reference Figure 1 An X-ray tube rotating anode control device includes a control console, a control unit, a drive circuit unit, a single-phase full-bridge inverter unit, an AC rectifier unit, an overcurrent detection unit, and a motor.

[0034] The output terminal of the control console is connected to the input terminal of the control unit, and the output terminal of the control unit is connected to the first input terminal of the drive circuit unit; the output terminal of the drive circuit unit is connected to the first input terminal of the single-phase full-bridge inverter unit, and the first output terminal of the single-phase full-bridge inverter unit is connected to the motor; the output terminal of the AC rectifier unit is connected to the second input terminal of the single-phase full-bridge inverter unit, and the second output terminal of the single-phase full-bridge inverter unit is connected to the overcurrent detection unit; the output terminal of the overcurrent detection unit is connected to the second input terminal of the drive circuit unit.

[0035] It should be noted that this control device is a high-low dual-speed start-up control system for the rotating anode of an X-ray tube in an X-ray machine system. It is designed to solve the problem of uneven heating of the anode target surface and easy damage to the target surface of the X-ray tube during long-term high-power exposure.

[0036] It should be noted that the control unit includes an MCU. The user selects the X-ray tube model and sets the power level through the console. The console sends instructions to the MCU control unit to determine the start-up mode (high speed or low speed) of the rotating anode.

[0037] It should be noted that the control unit (MCU control circuit) receives instructions from the console, generates corresponding control signals (such as SPWM and FPWM pulses), and outputs high-speed or low-speed start-up capacitor switching signals ( / H_Speed ​​and / L_Speed). It monitors overcurrent fault signals (Motor_Fault) and interrupts drive signals to protect the system in abnormal situations.

[0038] It should be noted that the drive circuit unit converts the SPWM and FPWM signals generated by the MCU into drive signals to control the operation of the single-phase full-bridge inverter unit. By adjusting the rise and fall times of the pulses, the dead time of the inverter switching transistors is ensured to prevent short-circuit damage.

[0039] It should be noted that the single-phase full-bridge inverter unit converts the DC bus voltage into AC voltage to drive the rotating anode motor of the X-ray tube. It outputs AC voltages of different frequencies (e.g., 180Hz for high speed, 60Hz for low speed) according to the MCU's instructions, achieving high-speed / low-speed start-up switching.

[0040] It should be noted that the AC rectifier unit provides the bus voltage for the single-phase full-bridge inverter unit.

[0041] It should be noted that the overcurrent detection unit detects the inverter output current and bus current through a current sensor chip, generating overcurrent fault signals (Motor_OCP and INV_OCP). In the event of an overcurrent, a fault signal is sent to the MCU, triggering the protection mechanism and stopping the drive signal output.

[0042] It should be noted that the motor (X-ray tube rotating anode motor) serves as the load, rotating at high speed (approximately 10,000 rpm) or low speed (approximately 3,000 rpm) according to the instructions of the control system to ensure uniform heat dissipation from the anode target surface.

[0043] Working principle overview: The user selects the X-ray tube model and power settings via the control panel (refer to...). Figure 2 As shown, the MCU generates corresponding drive signals according to instructions, controlling the inverter to output suitable AC voltage and frequency. Simultaneously, the system monitors the current status in real time, immediately cutting off the drive signal in case of overcurrent to protect the inverter and the X-ray tube. By switching between high and low speed start-up modes, the heat dissipation requirements of the anode target surface under different power levels are met, thereby extending the X-ray tube's lifespan and improving system reliability.

[0044] In the embodiments of this application, addressing the problem that existing X-ray tube rotating anode control methods are difficult to flexibly switch between different rotation speeds and cannot well adapt to X-ray tubes of different power, this application proposes an X-ray tube rotating anode control device, including a control console, a control unit, a drive circuit unit, a single-phase full-bridge inverter unit, an AC rectifier unit, an overcurrent detection unit, and a motor; the output terminal of the control console is connected to the input terminal of the control unit, and the output terminal of the control unit is connected to the first input terminal of the drive circuit unit; the output terminal of the drive circuit unit is connected to the first input terminal of the single-phase full-bridge inverter unit, and the first output terminal of the single-phase full-bridge inverter unit is connected to the motor; the output terminal of the AC rectifier unit is connected to the second input terminal of the single-phase full-bridge inverter unit, and the second output terminal of the single-phase full-bridge inverter unit is connected to the overcurrent detection unit; the output terminal of the overcurrent detection unit is connected to the second input terminal of the drive circuit unit. This device achieves real-time and precise control of the rotating anode speed through the coordinated operation of the control console, control unit, and drive circuit, meeting dynamic speed switching requirements under different inspection needs (e.g., continuously adjustable from 3000-10000 rpm), completely solving the adaptability problem of traditional fixed speed solutions. It employs an optimized combination of an AC rectifier unit and a single-phase full-bridge inverter unit to achieve highly efficient power conversion (conversion efficiency improved by more than 15%), while simultaneously reducing system heat generation and energy consumption.

[0045] In one embodiment, the control unit includes an MCU, the structure of which can be found in the diagram below. Figure 3 The MCU communicates with the console via an RS232 interface; the output of the RS232 interface is connected to an interface protection circuit. The MCU is also connected to an external clock circuit, a power-on reset circuit, and a voltage divider sampling circuit.

[0046] It should be noted that this RS232 interface is equipped with multiple protection circuits: TVS transient suppression diodes (TVS1-TVS3) are used to absorb electrostatic discharge and surge voltage, gas discharge tube (GDT1) provides high voltage protection, thermistors (RT1-RT2) suppress current surges, and LED indicators (LED1-LED2) are equipped to display the communication status in real time. The MCU peripheral circuit includes an external clock circuit consisting of a crystal oscillator (XT1) and matching capacitors (C18-C19) to ensure system timing accuracy; a power-on reset circuit consisting of diodes (D1), resistors (R7), and capacitors (C6) to ensure reliable startup through RC delay characteristics; and a voltage divider sampling circuit consisting of voltage divider resistors (R6, R8), filter capacitors (C8), and Zener diodes (DZ1) to accurately acquire the analog signal output by the current sensor (U2). These circuits work together to enable the system to accurately switch between high and low speed modes (high-speed 180Hz / low-speed 60Hz FPWM output) and have real-time overcurrent detection and protection functions. When an abnormal current is detected, the drive signal is immediately cut off to ensure the safe and reliable operation of the rotating anode of the X-ray tube.

[0047] In one embodiment, the driving circuit unit includes an inverter and an optocoupler; the input terminal of the inverter is connected to the output terminal of the control unit; and the output terminal of the inverter is connected to the input terminal of the optocoupler.

[0048] In one specific embodiment, the structure of the driving circuit unit is described in reference to... Figure 4 The drive circuit unit mainly includes the following core components: Inverters (such as U1A-U1F): used to logically invert the SPWM and FPWM signals output by the MCU to generate complementary drive signals. Optocouplers (optical isolators): used to achieve high and low voltage isolation to prevent high voltage interference from the inverter from damaging the MCU control circuit. RC delay circuits (D1-D4, R1-R4, C1-C4, etc.): used to adjust the rise and fall times of the drive signals to ensure dead time control.

[0049] It should be noted that the drive signal generation process is as follows: FPWM signal processing (controlling inverter output frequency): After the FPWM signal is output from the MCU, it passes through inverters (U1A, U1B, U1C) to generate two complementary signals. These two signals pass through RC delay circuits composed of D2, R3, R4, C2 and D1, R1, R2, C1, respectively, to adjust the rise and fall times, forming a certain dead time. The adjusted signals are then optocoupled and output as drive signals DR1 and DR2 to drive the upper arm (Q1) and lower arm (Q3) of the full-bridge inverter. SPWM signal processing (controlling inverter output voltage amplitude): After the SPWM signal is output from the MCU, it passes through inverters (U1D, U1E, U1F) to generate two complementary signals. These two signals pass through RC delay circuits composed of D3, R12, R13, C3 and D4, R10, R11, C4, respectively, to adjust the rise and fall times, ensuring the dead time.

[0050] The adjusted signal is isolated by an optocoupler and outputs drive signals DR3 and DR4 to drive the other upper arm (Q2) and lower arm (Q4) of the full-bridge inverter.

[0051] It's important to note the purpose of dead-time control: When the inverter is operating, if the IGBTs of the upper and lower bridge arms are simultaneously turned on (i.e., "shoot-through"), it will cause a short circuit and burn out the power transistors. The RC delay circuit creates a brief time difference (dead time) between the complementary drive signals during switching, ensuring that one IGBT is completely turned off before the other turns on, thus preventing shoot-through.

[0052] It's important to note the purpose of optocoupler isolation: Since the inverter operates in a high-voltage (540V DC) environment, while the MCU is a low-voltage (e.g., 3.3V or 5V) control circuit, direct connection could lead to high-voltage crosstalk damaging the MCU. Optocouplers achieve electrical isolation through photoelectric conversion, ensuring that the high-voltage drive signal does not affect the low-voltage control circuit, thus improving system reliability.

[0053] It should be noted that the driving waveform example is referenced. Figure 5 ,in:

[0054] FPWM signal: Outputs a 180Hz square wave during high-speed startup and a 60Hz square wave during low-speed startup.

[0055] SPWM signal: follows the periodic changes of FPWM to modulate an approximately sinusoidal AC voltage, which drives the rotating anode motor of the X-ray tube.

[0056] In one embodiment, the single-phase full-bridge inverter unit includes four insulated-gate bipolar transistors (IGBTs); the gate of each IGBT is connected to a protection diode; and the gate of each IGBT is also connected to a gate capacitor discharge control circuit.

[0057] In one embodiment, the four Insulated Gate Bipolar Transistors (IGBTs) are a first IGBT, a second IGBT, a third IGBT, and a fourth IGBT; wherein the first and third IGBTs form the upper bridge arm, and the second and fourth IGBTs form the lower bridge arm; the collectors of the first and third IGBTs are connected to the positive terminal of the DC power supply, and the emitters of the second and fourth IGBTs are connected to the negative terminal of the DC power supply; the emitter of the first IGBT and the collector of the second IGBT are connected at a connection point designated as point 1, and the emitter of the third IGBT and the collector of the fourth IGBT are connected at a connection point designated as point 2; the motor is connected between points 1 and 2; and the gate of each IGBT is connected to the drive circuit unit.

[0058] It should be noted that the inverter process is as follows: (For ease of description, the first insulated-gate bipolar transistor, the second insulated-gate bipolar transistor, the third insulated-gate bipolar transistor, and the fourth insulated-gate bipolar transistor will be referred to as Q1, Q2, Q3, and Q4, respectively.)

[0059] By alternately switching the upper and lower IGBTs on the bridge arms, the DC voltage (540V) is inverted into AC voltage. For example:

[0060] When Q1 and Q4 are turned on, the current path is: HV+ → Q1 → Motor → Q4 → GND.

[0061] When Q3 and Q2 are turned on, the current path is: HV+ → Q3 → motor → Q2 → GND.

[0062] By rapidly switching, an alternating voltage is generated across the motor terminals.

[0063] It should be noted that high and low speed control:

[0064] High-speed mode: The MCU outputs a 180Hz FPWM square wave, driving the motor to approximately 10,000 rpm.

[0065] Low speed mode: The MCU outputs a 60Hz FPWM square wave to drive the motor to approximately 3000 rpm.

[0066] It should be noted that the protection mechanism is as follows:

[0067] The current sensor (U2) detects the motor current. If an overcurrent is detected, a fault signal (Motor_Fault) is triggered, and the MCU immediately shuts off the drive signal to protect the circuit.

[0068] In one embodiment, the input terminal of the rectifier unit is connected to a three-phase 380V AC power supply.

[0069] It should be noted that the input of the rectifier unit is directly connected to an industrial standard three-phase 380V AC power supply (380V effective line voltage, 50Hz frequency). This rectifier unit mainly consists of a three-phase rectifier bridge module (DM1), whose AC input terminals (L1, L2, L3) are connected to the power grid via fuses and EMI filters, and can withstand voltage fluctuations of ±10%. The pulsating DC after rectification is smoothed by a π-type filter composed of large-capacity electrolytic capacitors (C15, C16), outputting a DC bus voltage (HV+) of approximately 540V (380V×√2). To suppress voltage spikes during rectification, an absorption circuit consisting of a varistor and an RC snubber circuit (R11, D9, C5) is installed on the DC bus side, effectively protecting the power devices in the subsequent inverter unit. This design not only meets the stringent power stability requirements of medical X-ray machines, but its instantaneous power handling capacity of up to 20kW also provides ample energy for the subsequent single-phase full-bridge inverter.

[0070] In one embodiment, the overcurrent detection unit includes two current sensor chips, which are used to detect the startup current and the inverter operating current, respectively; the overcurrent detection unit also includes a comparator and an OR gate circuit; when an overcurrent is detected, a fault signal is output to the control unit, and the control unit interrupts the drive signal output to protect the device.

[0071] It should be noted that the overcurrent detection unit adopts a redundant detection architecture, containing two high-precision current sensor chips (U1, U2) to monitor different key nodes: U2 is connected in series in the inverter output circuit to specifically detect the starting current of the rotating anode of the X-ray tube; U1 is installed between the DC bus (HV+) and the inverter bridge arm to monitor the inverter operating current in real time. The output signals of the two sensors are conditioned by independent operational amplifiers (U4) and then sent to high-speed comparators (U3A, U3B) for comparison with preset thresholds—U3A compares the starting current, and U3B compares the inverter current. When either current exceeds the limit, the corresponding comparator outputs a high-level fault signal (Motor_OCP or INV_OCP), which is combined into a unified Motor_Fault signal by hardware or gate circuits composed of diodes (D10, D11). This signal is then level-shifted by the Darlington driver chip (U5) and sent to the GPIO interrupt pin of the MCU with a millisecond-level response speed. The MCU immediately executes the protection protocol: it stops the output of SPWM and FPWM drive signals and simultaneously cuts off the motor power supply circuit of relay K3, achieving triple protection (software interrupt + hardware shutdown + mechanical isolation). This hierarchical detection and fast response design can distinguish between overcurrent faults in the startup and operation phases, and also prevent IGBTs (Q1-Q4) from breaking down due to instantaneous overcurrent, significantly improving system reliability.

[0072] In one embodiment, the single-phase full-bridge inverter unit is equipped with a temperature sensor, which is connected to the control unit.

[0073] It should be noted that the single-phase full-bridge inverter unit integrates a high-precision digital temperature sensor (such as DS18B20 or PT100). Its probe is directly mounted on the heat sink of the IGBT modules (Q1-Q4) and communicates with the MCU control unit in real time via I2C or a single-bus interface. This sensor monitors the operating temperature of the power devices with an accuracy of ±0.5℃. The sampled data is converted by the MCU's built-in ADC and dynamically compared with a preset safety threshold (typically 85℃). When an over-limit temperature is detected, the MCU immediately activates a tiered protection strategy: first, it reduces the SPWM modulation depth to decrease heat generation; if the temperature continues to rise to the second-level threshold (e.g., 100℃), it completely shuts off the drive signal and triggers the hardware protection circuit (cutting off the inverter power supply via optocoupler isolation). Simultaneously, the temperature data is uploaded to the PC control console via an RS232 interface, displaying the real-time temperature curve and alarm information on the operating interface. This active temperature monitoring design effectively solves the performance degradation problem of IGBTs caused by excessive junction temperature under high current conditions, improving the response time of traditional over-temperature protection from seconds to milliseconds. Combined with air-cooled / liquid-cooled heat dissipation systems, it ensures the stable operation of the inverter unit under long-term high-power exposure.

[0074] In one embodiment, the motor is an X-ray tube rotating anode motor; the control device outputs pulses of different widths according to the X-ray tube model selected by the control console to drive the corresponding X-ray tube rotating anode motor to start in high-speed or low-speed mode.

[0075] In one specific embodiment, the motor has its rotor directly coupled to the anode target disk and is supported by special alloy bearings to achieve high-speed operation of 3000-10000 revolutions per minute.

[0076] It should be noted that the control device dynamically adjusts the control strategy by parsing the X-ray tube model command sent by the PC console (such as "DRX-2933HQ" high-speed X-ray tube or "DRX-2530L" low-speed X-ray tube): For high-speed X-ray tubes, the MCU outputs a 180Hz FPWM square wave signal, while the SPWM modulation pulse width increases to 25μs, enabling the single-phase full-bridge inverter to output a 400Vp-p / 180Hz AC voltage, driving the motor to accelerate to 10000rpm within 0.8 seconds; for low-speed X-ray tubes, it switches to a 60Hz FPWM mode, the SPWM pulse width is reduced to 15μs, and a 320Vp-p / 60Hz voltage is output, achieving a smooth start at 3000rpm. Each mode is equipped with an independent starting capacitor bank (C3 / C4), which is automatically switched under MCU control via relays (K1 / K2) to ensure optimal starting characteristics for rotors with different inertia. The system monitors the motor's back electromotive force in real time and dynamically corrects the PWM parameters through a closed-loop algorithm, keeping the speed fluctuation within ±1%. This allows for precise matching of the heat dissipation requirements of different X-ray tubes on the anode target surface, solving the problem of localized melting of the target surface caused by speed mismatch.

[0077] In one embodiment, please refer to Figure 6 The overall structure of a 380V AC rectifier circuit, a single-phase full-bridge inverter circuit, and an overcurrent detection circuit is shown.

[0078] It should be noted that the three-phase 380V mains power input, after rectification by the DM1 module and filtering by capacitors C15 and C16, yields a DC voltage of approximately 540VDC, HV+, which serves as the input bus voltage for the single-phase full-bridge inverter. R11, D9, and C5 form a bus voltage absorption circuit to absorb voltage spikes generated during the switching process. R9 and C1 form the absorption circuit for switch Q2, and R10 and C2 form the absorption circuit for switch Q4, preventing overvoltage damage to the IGBTs due to excessive voltage spikes during turn-off. The single-phase full-bridge inverter consists of four IGBT power transistors: Q1, Q2, Q3, and Q4. TVS1, TVS2, TVS3, and TVS4 are gate protection diodes for Q1, Q2, Q3, and Q4, preventing overvoltage damage to the IGBT gates.

[0079] It should be noted that R24, D1, D3, R1, R3, and Q5 constitute the gate capacitor discharge control circuit of Q1. During the Q1 turn-on process, the drive signal DR1 charges the gate capacitor of Q1 through R24, D1, and R1. During the Q1 turn-off process, the voltage on the gate capacitor of Q1 is rapidly discharged through R1, Q5, and GNDH1.

[0080] It should be noted that R26, D4, D5, R4, R7, and Q6 form the gate capacitor discharge control circuit of Q2. During the Q2 turn-on process, the drive signal DR2 charges the gate capacitor of Q2 through R26, D5, and R7. During the Q2 turn-off process, the voltage on the gate capacitor of Q2 is rapidly discharged through R7, Q6, and GNDL.

[0081] It should be noted that R25, D2, D6, R2, R5, and Q7 form the gate capacitor discharge control circuit of Q3. During the Q3 turn-on process, the drive signal DR3 charges the gate capacitor of Q3 through R25, D2, and R2. During the Q3 turn-off process, the voltage on the gate capacitor of Q3 is rapidly discharged through R2 and Q7 to GNDH1.

[0082] It should be noted that R27, D7, D8, R6, R12, and Q8 form the gate capacitor discharge control circuit of Q4. During the Q4 turn-on process, the drive signal DR4 charges the gate capacitor of Q4 through R27, D8, and R12. During the Q4 turn-off process, the voltage on the gate capacitor of Q4 is rapidly discharged through R12, Q8, and GNDH1.

[0083] It should be noted that L1 and L2 are two filter inductors for the inverter output, and U2 is a current sensor chip connected in series in the circuit from the inverter output to the X-ray tube anode. It is used to detect whether the starting current is normal. One output of the U2 current sensor is sent to comparator U3A for overcurrent detection. If there is an overcurrent during startup, comparator U3A outputs a high-level overcurrent fault signal Motor_OCP. This signal, along with the INV_OCP signal, is ORed with a gate composed of diodes D10 and D11 to output the Motor_Fault signal. Figure 3 After level conversion by U5, the signal is sent to the microcontroller. Upon receiving the Motor_Fault fault signal, the microcontroller immediately interrupts the output of the SPWM and FPWM drives to protect the inverter and X-ray tube. Another path of the current detection output from U2 is rectified and filtered by operational amplifier U4, diode D12, and capacitor C11 to obtain the analog sampling voltage COM_AD of the starting current. This analog voltage signal is then... Figure 3 The voltage divider circuit in the circuit sends the signal to the microcontroller for detection to ensure that the starting current is within the set range; otherwise, an error is reported and the output of the SPWM and FPWM drives is interrupted.

[0084] It should be noted that U1 is a current sensor chip, connected in series in the circuit of HV+, upper bridge arm, lower bridge arm, and 0V of the inverter, used to detect whether the inverter is operating with overcurrent. The current detection output of U1 is sent to comparator U3B for inverter overcurrent detection. If the inverter is operating abnormally with overcurrent, comparator U3B outputs a high-level overcurrent fault signal INV_OCP. This signal and the Motor_OCP signal are ORed by a gate composed of two diodes D10 and D11 to output the Motor_Fault signal. Figure 3 After level conversion by U5, the signal is sent to the microcontroller. Upon receiving the Motor_Fault fault signal, the microcontroller immediately interrupts the output of the SPWM and FPWM drives to protect the inverter and the X-ray tube.

[0085] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0086] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0087] The X-ray tube rotating anode control device provided in this application has been described in detail above. Specific examples have been used to illustrate the principle and implementation of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​this application. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A rotating anode control device for an X-ray tube, characterized in that, include: The control console, control unit, drive circuit unit, single-phase full-bridge inverter unit, AC rectifier unit, overcurrent detection unit, and motor; The output terminal of the console is connected to the input terminal of the control unit, and the output terminal of the control unit is connected to the first input terminal of the drive circuit unit. The output terminal of the drive circuit unit is connected to the first input terminal of the single-phase full-bridge inverter unit, and the first output terminal of the single-phase full-bridge inverter unit is connected to the motor. The output terminal of the AC rectifier unit is connected to the second input terminal of the single-phase full-bridge inverter unit, and the second output terminal of the single-phase full-bridge inverter unit is connected to the overcurrent detection unit. The output terminal of the overcurrent detection unit is connected to the second input terminal of the drive circuit unit.

2. The control device according to claim 1, characterized in that, The driving circuit unit includes an inverter and an optocoupler; The input terminal of the inverter is connected to the output terminal of the control unit; The output terminal of the inverter is connected to the input terminal of the optocoupler.

3. The control device according to claim 1, characterized in that, The single-phase full-bridge inverter unit includes four insulated-gate bipolar transistors; Each of the insulated gate bipolar transistors has a protection diode connected to its gate; Each of the insulated gate bipolar transistors is also connected to a gate capacitor discharge control circuit.

4. The control device according to claim 3, characterized in that, The four insulated-gate bipolar transistors are a first insulated-gate bipolar transistor, a second insulated-gate bipolar transistor, a third insulated-gate bipolar transistor, and a fourth insulated-gate bipolar transistor; wherein the first insulated-gate bipolar transistor and the third insulated-gate bipolar transistor are the upper bridge arms, and the second insulated-gate bipolar transistor and the fourth insulated-gate bipolar transistor are the lower bridge arms; The collectors of the first and third insulated-gate bipolar transistors are connected to the positive terminal of the DC power supply, and the emitters of the second and fourth insulated-gate bipolar transistors are connected to the negative terminal of the DC power supply. The emitter of the first insulated gate bipolar transistor is connected to the collector of the second insulated gate bipolar transistor, and the connection point is called the first point. The emitter of the third insulated gate bipolar transistor is connected to the collector of the fourth insulated gate bipolar transistor, and the connection point is called the second point. The motor is connected between the first point and the second point. The gate of each of the insulated gate bipolar transistors is connected to the drive circuit unit.

5. The control device according to claim 1, characterized in that, The input terminal of the rectifier unit is connected to a three-phase 380V AC power supply.

6. The control device according to claim 1, characterized in that, The overcurrent detection unit includes two current sensor chips, which are used to detect the startup current and the inverter operating current, respectively. The overcurrent detection unit also includes a comparator and an OR gate circuit; When an overcurrent is detected, a fault signal is output to the control unit, which then interrupts the drive signal output to protect the device.

7. The control device according to claim 1, characterized in that, The single-phase full-bridge inverter unit is equipped with a temperature sensor, which is connected to the control unit.

8. The control device according to claim 1, characterized in that, The motor is an X-ray tube rotary anode motor; The control device outputs pulses of different widths according to the X-ray tube model selected by the console, so as to drive the corresponding X-ray tube rotating anode motor to start in high-speed or low-speed mode.

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