Cooperative control system for fast scanning magnet power supply

Abstract

The invention provides a cooperative control system for a fast scanning magnet power supply, and relates to the technical field of scanning power supply control, the system comprises an error acquisition module, a dynamic module, a static module and a control module; the control module comprises a dynamic module switching control module and a closed-loop control module; the dynamic module and the static module are cascaded, and a circuit formed by cascading is connected between a scanning magnet power supply and a magnet load and provides driving current for the magnet load; the error acquisition module is used for acquiring a current error signal between an actual load current output to the magnet load and a current given target value; the dynamic module switching control module is used for controlling input and exit of a dynamic module by adopting hysteresis comparison logic based on the absolute value of the current error signal; and the closed-loop control module is used for stopping current error integral accumulation during the input period of the dynamic module and recovering the current error integral when the dynamic module exits working, and is used for simultaneously realizing an ultrahigh current change rate and high steady-state precision.

Description

Technical Field

[0001] This invention relates to the field of scanning power supply control technology, and more specifically, to a cooperative control system for a fast scanning magnet power supply. Background Technology

[0002] In advanced medical fields such as proton radiotherapy, point-beam scanning technology is the core of achieving precision treatment. This technology relies on a fast-scanning magnet power supply to drive a magnet coil to generate a rapidly and precisely changing magnetic field, guiding the particle beam to precisely target the tumor area point by point.

[0003] To improve treatment efficiency and ensure treatment accuracy, extremely stringent technical requirements are placed on fast-scanning magnet power supplies: achieving an extremely high rate of current change during the rapid current transition phase while maintaining extremely high steady-state accuracy during the current stabilization phase. This presents an inherent technical contradiction. To achieve a high rate of current change, a very high voltage needs to be applied across the load, based on the characteristics of the inductive load; while to achieve high steady-state accuracy, the power supply needs to possess precise low-voltage regulation capabilities and extremely low output ripple.

[0004] In related technologies, a common topology is to cascade high- and low-voltage power supply modules to address dynamic and static requirements respectively. However, the control strategies used are often relatively simple and difficult to handle the extreme performance requirements. For example, some solutions use a long timing method to control the activation time of the high-voltage module, but this open-loop approach struggles to accurately handle nonlinearities in load parameter changes or current rise, resulting in significant current errors at the switching point. Other solutions employ simple single-threshold switching logic, where the high-voltage module is switched off when the current error falls below a certain value. This approach is highly susceptible to signal noise or minor system oscillations in high-speed, high-precision systems, causing frequent and unstable start-ups and shutdowns of the high-voltage module near the switching point, which ultimately degrades system performance. Summary of the Invention

[0005] The problem solved by this invention is how to simultaneously achieve ultra-high current change rate and high steady-state accuracy.

[0006] To address the aforementioned problems, this invention provides a cooperative control system for fast-scanning magnet power supplies.

[0007] In a first aspect, the present invention provides a collaborative control system for a fast-scanning magnet power supply, comprising an error acquisition module, a dynamic module, a static module, and a control module; The control module includes a dynamic module switching control module and a closed-loop control module; The dynamic module and the static module are cascaded together, and the cascaded circuit is connected between the scanning magnet power supply and the magnet load to provide drive current to the magnet load. The error acquisition module is used to acquire the current error signal between the actual load current output to the magnet load and the current given target value; The dynamic module switching control module is used to control the activation and deactivation of the dynamic module based on the absolute value of the current error signal and employing hysteresis comparison logic. The closed-loop control module is used to stop the accumulation of current error integral during the operation of the dynamic module and to resume the accumulation of current error integral when the dynamic module is shut down.

[0008] Optionally, the dynamic module switching control module is specifically used to: control the dynamic module to start working when the absolute value of the current error signal is greater than a first preset threshold, and trigger the dynamic bridge switching-out signal to control the dynamic module to stop working when the absolute value of the current error signal is less than a second preset threshold, wherein the first preset threshold is greater than the second preset threshold.

[0009] Optionally, the closed-loop control module includes an outer-loop control module and an inner-loop control module; The outer loop control module takes the current error signal as input and outputs the target value of the current through proportional-integral control. The inner loop control module takes the inductor current error of each stage module branch as input and adjusts the output of each module branch through proportional-integral control. The module branch includes dynamic modules and static modules. The inductor current error is the difference between the inductor current of the module branch and the current given target value.

[0010] Optionally, the inner loop control module includes a proportional controller, which is configured to correspond to the static module and is used to determine the corresponding module branch output based on the inductor current error.

[0011] Optionally, the outer loop control module is also used to receive the dynamic bridge cut-out signal. When the dynamic bridge cut-out signal is negative, the current error integral accumulation is stopped; when the dynamic bridge cut-out signal is positive, the current error integral is resumed.

[0012] Optionally, the outer loop control module is also used to determine the linear integral coefficient based on the current given target value, and to perform current error integration based on the linear integral coefficient.

[0013] Optionally, the outer loop control module is also used to clear the integral accumulation value to zero when the target current value changes abruptly.

[0014] Optionally, the control module may also include an outer loop feedforward module; The outer loop feedforward module is used to generate the outer loop feedforward control quantity based on the target value of the current, and inject the outer loop feedforward control quantity into the output of the outer loop control module.

[0015] Optionally, the control module may also include an inner loop feedforward module; The inner loop feedforward module is used to generate the inner loop feedforward quantity based on the target value of the current, and inject the inner loop feedforward quantity into the output of the inner loop control module.

[0016] Optionally, the control module may also include a dynamic output limiting module; The dynamic output limiting module is used to dynamically adjust the upper and lower limits of the inner loop control module output according to the theoretical duty cycle in order to limit the sudden changes in the control quantity. The theoretical duty cycle is calculated from the current target value and the bus voltage.

[0017] The beneficial effects of the cooperative control system for fast-scanning magnet power supplies of the present invention are: The control module is divided into a dynamic module switching control module and a closed-loop control module, forming two independent but coordinated logic units: dynamic response and steady-state regulation. This allows for separate optimization of high-voltage drive and low-voltage current regulation. The dynamic module provides high voltage to support the rapid drive capability required for large current change rates; the static module features low noise and low ripple output characteristics, suitable for fine-tuning in the steady-state phase. Both modules are cascaded and connected to the load, dominating power supply in different operating phases, thus meeting the dual performance requirements of speed and stability from a physical architecture perspective.

[0018] The error acquisition module reflects the deviation between the actual output current of the magnet load and the given target value in real time, providing a unified and reliable decision-making basis for the dynamic module's activation or deactivation and the static module's feedback adjustment. The control module communicates with the error acquisition module, allowing control actions to be directly based on actual operating errors. This avoids the insufficient adaptability caused by open-loop timing or fixed-sequence switching, enhancing robustness to load parameter changes and operating condition disturbances. During the operation of the dynamic module, the closed-loop control module pauses the integral accumulation of current error to prevent integral saturation caused by large errors. When the dynamic module deactivates, the integral function is immediately restored, enabling the static module to quickly participate in regulation with a reasonable initial integral value. This effectively eliminates current overshoot and long recovery periods caused by integral saturation in traditional schemes, shortens the time required for the current to enter the steady-state error band, and ultimately achieves both ultra-high current change rate and high steady-state accuracy. Attached Figure Description

[0019] Figure 1 This is a system block diagram of a cooperative control system for a fast-scanning magnet power supply according to an embodiment of the present invention; Figure 2 This is a topology diagram of a cooperative control system for a fast-scanning magnet power supply according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the hysteresis comparison logic of the cooperative control system for a fast-scanning magnet power supply according to an embodiment of the present invention. Figure 4 This is a control block diagram of the closed-loop control of the cooperative control system for a fast-scanning magnet power supply according to an embodiment of the present invention. Figure 5 This is an ideal current response waveform diagram of the dynamic and static modules of the collaborative control system for fast scanning magnet power supply in an embodiment of the present invention when they work together. Detailed Implementation

[0020] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the accompanying drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0021] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0022] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this invention are used only to distinguish different devices, modules, or units, and are not intended to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0023] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0024] The names of the messages or information exchanged between the multiple devices in the embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0025] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a collaborative control system for a fast-scanning magnet power supply, including an error acquisition module, a dynamic module, a static module, and a control module; The control module includes a dynamic module switching control module and a closed-loop control module; The dynamic module and the static module are cascaded together, and the cascaded circuit is connected between the scanning magnet power supply and the magnet load to provide drive current to the magnet load. The error acquisition module is used to acquire the current error signal between the actual load current output to the magnet load and the current given target value; The dynamic module switching control module is used to control the activation and deactivation of the dynamic module based on the absolute value of the current error signal and employing hysteresis comparison logic. The closed-loop control module is used to stop the accumulation of current error integral during the operation of the dynamic module and to resume the accumulation of current error integral when the dynamic module is shut down.

[0026] The fast-scanning magnet power supply system of this invention mainly consists of a pre-stage rectifier and filter circuit, a dynamic module H-bridge 1, two staggered parallel static module H-bridges 2, and a magnet load 3. The DC bus voltage (VH) of the dynamic module is significantly higher than the DC bus voltage (VL) of the static module. The entire system is controlled by a digital controller 4.

[0027] The error acquisition module is used to collect the actual current of the magnet load in real time and compare it with the target current value issued by the upper system to generate a current error signal. This error signal can reflect the deviation between the current output and the expected target.

[0028] The dynamic module represents a high-voltage power conversion unit with a significantly higher voltage than the static module. It is used to apply a high voltage to the magnet load during rapid current changes to achieve an extremely high rate of current change (di / dt). The static module represents a low-voltage precision current regulator unit with a lower voltage and smaller output ripple, suitable for high-precision regulation during the current stabilization phase. Both are cascaded between the scanning magnet power supply and the magnet load, forming a composite power supply structure that balances dynamic response capability and steady-state control performance.

[0029] The control module is the core of realizing the dynamic-static coordination of the technical solution in the embodiments of the present invention. As shown in Figure 1, the control module represents a digital controller, which includes a dynamic module switching control module and a closed-loop control module. The control module is used to receive the current error signal from the error acquisition module and coordinate the working state of the two power modules according to the current error signal.

[0030] The dynamic module switching control module uses hysteresis comparison logic to judge the absolute value of the current error signal. For example, when the absolute value of the error is greater than a first preset threshold, the dynamic module is activated; when the absolute value of the error is less than a second preset threshold, the dynamic module is deactivated. The first preset threshold being greater than the second preset threshold forms a hysteresis interval. This effectively suppresses the problem of repeated start-stop of the dynamic module near the critical point caused by signal noise or small system oscillations due to measurement noise or small oscillations, greatly enhancing the system's operational stability under high current change rates.

[0031] The closed-loop control module pauses the integral accumulation of current error while the dynamic module is in operation; it immediately resumes the integral function when the dynamic module is out of operation. This avoids the phenomenon of integral saturation caused by the continuous action of large errors in traditional control, thereby preventing current overshoot at the moment the dynamic module switches off and achieving a smooth transition from high-voltage drive to low-voltage precision regulation.

[0032] In this embodiment, the control module is divided into a dynamic module switching control module and a closed-loop control module, forming two independent but coordinated logic units: dynamic response and steady-state regulation. This allows for separate optimization of high-voltage drive and low-voltage current regulation. The dynamic module provides high voltage to support the rapid drive capability required for large current change rates; the static module features low noise and low ripple output characteristics, suitable for fine-tuning in the steady-state phase. Both modules are cascaded and connected to the load, dominating power supply in different operating phases, thus meeting the dual performance requirements of speed and stability from a physical architecture perspective.

[0033] The error acquisition module reflects the deviation between the actual output current of the magnet load and the given target value in real time, providing a unified and reliable decision-making basis for the dynamic module's activation or deactivation and the static module's feedback adjustment. The control module communicates with the error acquisition module, allowing control actions to be directly based on actual operating errors. This avoids the insufficient adaptability caused by open-loop timing or fixed-sequence switching, enhancing robustness to load parameter changes and operating condition disturbances. During the operation of the dynamic module, the closed-loop control module pauses the integral accumulation of current error to prevent integral saturation caused by large errors. When the dynamic module deactivates, the integral function is immediately restored, enabling the static module to quickly participate in regulation with a reasonable initial integral value. This effectively eliminates current overshoot and long recovery periods caused by integral saturation in traditional schemes, shortens the time required for the current to enter the steady-state error band, and ultimately achieves both ultra-high current change rate and high steady-state accuracy.

[0034] Optionally, the dynamic module switching control module is specifically used to: control the dynamic module to start working when the absolute value of the current error signal is greater than a first preset threshold, and trigger the dynamic bridge switching-out signal to control the dynamic module to stop working when the absolute value of the current error signal is less than a second preset threshold, wherein the first preset threshold is greater than the second preset threshold.

[0035] In this embodiment, the dynamic module switching control module determines the working state of the dynamic module based on the comparison between the absolute value of the current error signal and two preset thresholds. The first preset threshold is the activation threshold of the dynamic module, and the second preset threshold is the deactivation threshold, with the former being greater than the latter, forming a hysteresis interval between them.

[0036] When the absolute value of the current error signal exceeds the first preset threshold, it indicates that the current output current is far from the target value and a high voltage drive is required to speed up the response. At this time, the dynamic module is put into operation. When the absolute value of the current error signal drops to below the second preset threshold, it indicates that the current has approached the target area and the high voltage drive is no longer necessary. The dynamic module then exits.

[0037] Because different thresholds are used for input and output, even if the current error fluctuates in the critical region due to measurement noise or minor oscillations, it will not cause the dynamic module to repeatedly start and stop. This hysteresis mechanism enhances the stability of the switching logic, avoids frequent jumps in control actions, and creates conditions for the smooth takeover of the subsequent static module. This control method can be implemented through comparator logic in a digital controller, and the two thresholds can be preset and stored in the control parameter table according to load characteristics and performance indicators.

[0038] like Figure 3 As shown in the figure, the first preset threshold TH_H is set to 15, and the second preset threshold TH_L is set to 10. In this embodiment, these two thresholds form a 5A hysteresis band, ensuring the stability of the control logic. When the current error ΔI decreases from a large value to below 10A, the dynamic module is switched off; and only when the error increases back to above 15A will the dynamic module be reactivated, effectively avoiding repeated jumps in the control logic caused by signal noise and other factors within the critical range of 10A to 15A.

[0039] Optionally, such as Figure 4 As shown, the closed-loop control module includes an outer loop control module and an inner loop control module; The outer loop control module takes the current error signal as input and outputs the target value of the current through proportional-integral control. The inner loop control module takes the inductor current error of each stage module branch as input and adjusts the output of each module branch through proportional-integral control. The module branch includes dynamic modules and static modules. The inductor current error is the difference between the inductor current of the module branch and the current given target value.

[0040] In this embodiment, the closed-loop control module consists of an outer-loop control module and an inner-loop control module, forming a dual-closed-loop structure. The outer-loop control module receives the current error signal I_err as input, which is the deviation between the actual current I_initial of the magnet load and the original current setpoint target value I_ref. The outer-loop PI controller, based on the current setpoint value I_ref and multiplied by an adjustable outer-loop feedforward coefficient Kpre_Io to compensate for most of the steady-state components, performs proportional-integral calculation on the current error signal I_err. Its output serves as the current reference command for the inner loop, i.e., the new current setpoint target value, to guide the inner loop adjustment.

[0041] The inner loop control module sets up independent adjustment channels for each branch in the static module. It takes the deviation (I_Lref-ILx) between the actual value of the inductor current ILx of each branch and the inner loop current reference command I_Lref as input, and generates corresponding drive signals through their respective inner loop PI controllers Kp_IL to adjust the conduction state of the power devices in each branch, thereby achieving dynamic balance and fast response of the current between branches.

[0042] The dual-loop structure decouples the total current control from the branch current sharing control. The outer loop focuses on overall steady-state performance, while the inner loop ensures coordinated operation between cascaded units. The control architecture can be implemented using a multi-channel control algorithm in a digital controller. The PI parameters of the outer and inner loops can be tuned separately according to the load inductance, the number of branches, and dynamic response requirements, thereby improving overall control performance.

[0043] Optionally, the inner loop control module includes a proportional controller, which is configured to correspond to the static module and is used to determine the corresponding module branch output based on the inductor current error.

[0044] In this embodiment, the outer loop control module employs a proportional-integral (PI) control algorithm to process the current error, where the integral operation is used to accumulate the change in current error over time. This eliminates residual deviations in the steady-state phase and improves the long-term stability of current tracking.

[0045] When the dynamic module is in the deactivated state, the outer loop control module activates the integral function to gradually approach the target value. During the activation of the dynamic module, integration is paused to prevent excessive accumulation of integral values ​​due to large errors. The activation and deactivation of the integral stage are controlled in conjunction with the operating status of the dynamic module, avoiding overshoot caused by integral saturation during switching.

[0046] In this embodiment, the inner loop control module includes a proportional controller, and the proportional controller is provided corresponding to each parallel branch of the static module. The proportional controller takes the inductor current error of the corresponding branch as the input, that is, the deviation between the actual inductor current of the branch and the inner loop current reference command, and generates a corresponding control output based on this error, which is used to adjust the power device drive signal of the corresponding module branch. This enables each branch to independently respond to its own current deviation, achieving dynamic current sharing and fast local regulation.

[0047] Optionally, the outer loop control module is further configured to receive a dynamic bridge cut-out signal. When the dynamic bridge cut-out signal is NO, the current error integration accumulation is stopped; when the dynamic bridge cut-out signal is YES, the current error integration is restored.

[0048] In this embodiment, the outer loop control module is further configured to receive a dynamic bridge cut-out signal, and the dynamic bridge cut-out signal is used to characterize the working state of the dynamic module. When the dynamic bridge cut-out signal is NO, it indicates that the dynamic module is in the working state. At this time, the outer loop control module pauses the integration accumulation of the current error to prevent the integration amount from saturating due to the continuous action of a large error; when the dynamic bridge cut-out signal is YES, it indicates that the dynamic module has exited the working state, and the outer loop control module immediately restores the integration function of the current error, enabling the integral term to participate in the steady-state regulation.

[0049] The linkage control between the integral link and the switching state of the dynamic module is realized, avoiding the problem of current overshoot at the moment of switching due to integral saturation in traditional control, which helps the static module quickly and smoothly take over the current regulation task. The dynamic bridge cut-out signal can be generated by the control module according to the hysteresis comparison logic and transmitted to the outer loop control module in the form of a digital level. The integral start-stop operation is achieved by setting or clearing the integral accumulator.

[0050] Optionally, the outer loop control module is further configured to determine a linear integral coefficient according to the current current given target value and perform current error integration according to the linear integral coefficient.

[0051] In this embodiment, the outer loop control module determines the corresponding linear integral coefficient Ki_Io according to the current current given target value I_ref, and performs integral operation on the current error with this coefficient , where T represents the sampling period and z represents the complex variable in the z-transform. The linear integral coefficient is not a fixed value, but is set in segments according to the interval where the current given target value is located to adapt to the non-linear characteristics presented by the magnet load at different working points.

[0052] When the current given target value is large, a smaller integral coefficient is adopted to suppress the integral speed and avoid overshoot in the response process; when the current given target value is small, a larger integral coefficient is adopted to accelerate the steady-state convergence. This enables the integral effect to be adaptively adjusted according to the working conditions, improving the steady-state regulation efficiency while maintaining dynamic stability.

[0053] This function can be implemented through table lookup or piecewise function. Multiple current ranges and their corresponding integral coefficients are pre-stored in the controller parameter area. During operation, the appropriate integral coefficient is automatically selected based on the real-time current target value and applied to the gain calculation of the integral stage.

[0054] Optionally, the outer loop control module is also used to clear the accumulated value of the integral element to zero when the target value of the current changes abruptly.

[0055] In this embodiment, the outer loop control module monitors changes in the target current value. When a step change in the target current value is detected, it is determined that the load operating point has shifted, and the accumulated value of the integral element is reset to zero. This prevents the integral value accumulated at the old operating point from interfering with the adjustment process of the new target value. If it is not reset, the original integral value may be opposite to the new error direction or too large, resulting in output response delay, reverse overshoot, or oscillation. By resetting the integral accumulated value at the step change moment, the controller starts responding to new commands from a zero initial integral state, improving the smoothness and convergence speed of the dynamic transition process.

[0056] A step change can be determined by comparing the current target value with that of the previous cycle. When the difference between the two exceeds a preset threshold, it is considered a step event. The integral clearing action is triggered by the control module, which directly sets the integral accumulator register to zero.

[0057] Optionally, such as Figure 4 As shown, the control module also includes an outer loop feedforward module; The outer loop feedforward module is used to generate the outer loop feedforward control quantity based on the target value of the current, and inject the outer loop feedforward control quantity into the output of the outer loop control module.

[0058] In this embodiment, the control module includes an outer loop feedforward module, which generates an outer loop feedforward control quantity based on the target value of the current, and superimposes the feedforward control quantity onto the output of the outer loop control module.

[0059] The outer loop feedforward control is used to compensate for most of the steady-state components based on the current setpoint I_ref and multiplied by an adjustable feedforward coefficient Kpre_Io.

[0060] The outer loop feedforward control quantity is obtained by multiplying the current setpoint target value by the feedforward gain coefficient, which can be set according to the equivalent resistance of the magnet load or offline calibration data.

[0061] Optionally, such as Figure 4 As shown, the control module also includes an inner loop feedforward module, which is used to generate an inner loop feedforward quantity based on the current given target value and inject the inner loop feedforward quantity into the output terminal of the inner loop control module.

[0062] In this embodiment, the control module includes an inner-loop feedforward module, which generates an inner-loop feedforward quantity according to the current given target value, and superimposes the inner-loop feedforward quantity on the output end of the inner-loop control module to participate in the inner-loop regulation together with the branch inductance current error signals of each branch.

[0063] The inner-loop feedforward quantity multiplies the real-time current given value I_ref by an adjustable inner-loop feedforward coefficient Kpre_IL to calculate the theoretical inner-loop feedforward quantity.

[0064] Optionally, as Figure 4 shown, it further includes a dynamic output limiting module; The dynamic output limiting module is used to dynamically adjust the upper and lower limits of the output of the inner-loop control module according to the theoretical duty cycle to limit the sudden change of the control quantity, where the theoretical duty cycle is obtained by calculating the current given target value and the bus voltage.

[0065] In this embodiment, the dynamic output limiting module sets dynamic upper and lower limits for the output of the inner-loop control module according to the theoretical duty cycle to prevent the sudden change of the control quantity during switching or disturbance. The theoretical duty cycle is calculated from the current given target value and the static module bus voltage, reflecting the steady-state drive level required to maintain the target current at the current operating point. It is used to constrain the output of the inner-loop control module to always be within a reasonable range, avoiding output saturation or overshoot caused by integral accumulation or error transients. Especially in the transition stage when the dynamic module exits and the static module takes over, it can effectively suppress current oscillation or overshoot. The upper and lower limit values are updated in real time with the theoretical duty cycle to make the limiting boundary match the actual working conditions, taking into account both the adjustment margin and stability.

[0066] The dynamic output limiting module receives the current given target value and the known bus voltage, calculates the theoretical duty cycle through a preset formula or a look-up table method, and generates the corresponding output limiting values accordingly.

[0067] As Figure 5 shown, the working process includes: in the initial state, the actual output current of the magnet load at t < t1 is a certain initial value, and the power supply output current is I_initial. At this time, the error acquisition module receives a new current given target value I_ref and calculates the corresponding current error signal I_err. The control module receives this current error signal I_err and judges whether the absolute value |I_err| is greater than the first preset threshold.

[0068] When the absolute value of the current error signal is greater than the first preset threshold, it enters the dynamic module startup stage (t1 - t2 stage). The dynamic module switching control module inserts the dynamic module to provide drive current to the magnet load together with the static module. At the same time, the closed-loop control module stops the integral accumulation of the current error signal to prevent integral saturation.

[0069] During the operation of the dynamic module, the control module continuously monitors the absolute value of the current error signal. In phase 2-t3, when this absolute value drops below the second preset threshold, the dynamic module switching control module exits the dynamic module. At this point, the closed-loop control module resumes its current error integration function, and the static module independently completes subsequent adjustments.

[0070] Throughout the process, the outer loop feedforward module generates an outer loop feedforward control quantity based on the target current value and injects it into the output of the outer loop PI controller; the inner loop feedforward module synchronously generates an inner loop feedforward quantity and injects it into the output of the inner loop controller. The dynamic output limiting module dynamically adjusts the upper and lower limits of the PI controller output based on the theoretical duty cycle calculated from the target current value and the bus voltage, limiting sudden changes in the control quantity.

[0071] If the target current value changes abruptly, the closed-loop control module resets the accumulated value of the integral terminator to zero. Simultaneously, it selects the corresponding linear integral coefficient based on the current target current value for subsequent integral calculations. The outer-loop control module receives the dynamic bridge cut-out signal and controls the start and stop of the integral accumulation based on its state, achieving smooth switching between the dynamic and static modules.

[0072] After time t3, under the control of the static module, the load current smoothly enters the preset ±1A target error band and stabilizes within a short period of time (t2~t3) until the end of the entire control cycle.

[0073] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc. In this application, the units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments of the present invention according to actual needs. Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated units described above can be implemented in hardware or as software functional units.

[0074] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A cooperative control system for a fast-scanning magnet power supply, characterized in that, It includes an error acquisition module, a dynamic module, a static module, and a control module; The control module includes a dynamic module switching control module and a closed-loop control module; The dynamic module and the static module are cascaded together, and the cascaded circuit is connected between the scanning magnet power supply and the magnet load to provide drive current for the magnet load. The error acquisition module is used to acquire the current error signal between the actual load current output to the magnet load and the current given target value; The dynamic module switching control module is used to control the activation and deactivation of the dynamic module based on the absolute value of the current error signal and using hysteresis comparison logic. The closed-loop control module is used to stop the accumulation of current error integral during the operation of the dynamic module and to restore the current error integral when the dynamic module is shut down.

2. The cooperative control system for a fast-scanning magnet power supply according to claim 1, characterized in that, The dynamic module switching control module is specifically used to: control the dynamic module to start working when the absolute value of the current error signal is greater than a first preset threshold, and trigger a dynamic bridge cut-out signal to control the dynamic module to stop working when the absolute value of the current error signal is less than a second preset threshold, wherein the first preset threshold is greater than the second preset threshold.

3. The cooperative control system for a fast-scanning magnet power supply according to claim 2, characterized in that, The closed-loop control module includes an outer loop control module and an inner loop control module; The outer loop control module takes the current error signal as input and outputs the current target value through proportional-integral control. The inner loop control module takes the inductor current error of each stage of the module branch as input and adjusts the output of each module branch through proportional-integral control. The module branch includes the dynamic module and the static module. The inductor current error is the difference between the inductor current of the module branch and the given target value of the current.

4. The cooperative control system for a fast-scanning magnet power supply according to claim 3, characterized in that, The inner loop control module includes a proportional controller, which is configured to correspond to the static module and is used to determine the corresponding module branch output based on the inductor current error.

5. The cooperative control system for a fast-scanning magnet power supply according to claim 3, characterized in that, The outer loop control module is also used to receive the dynamic bridge cut-out signal. When the dynamic bridge cut-out signal is negative, the current error integral accumulation is stopped; when the dynamic bridge cut-out signal is positive, the current error integral is resumed.

6. The cooperative control system for a fast-scanning magnet power supply according to claim 4, characterized in that, The outer loop control module is also used to determine the linear integral coefficient based on the current given target value, and to perform the current error integration based on the linear integral coefficient.

7. The cooperative control system for a fast-scanning magnet power supply according to claim 4, characterized in that, The outer loop control module is also used to clear the integral accumulation value to zero when the target value of the current undergoes a step change.

8. The cooperative control system for a fast-scanning magnet power supply according to claim 3, characterized in that, The control module also includes an outer loop feedforward module; The outer loop feedforward module is used to generate an outer loop feedforward control quantity based on the given target value of the current, and inject the outer loop feedforward control quantity into the output terminal of the outer loop control module.

9. The cooperative control system for a fast-scanning magnet power supply according to claim 3, characterized in that, The control module also includes an inner loop feedforward module; The inner loop feedforward module is used to generate an inner loop feedforward quantity based on the given target value of the current, and inject the inner loop feedforward quantity into the output terminal of the inner loop control module.

10. The cooperative control system for a fast-scanning magnet power supply according to claim 3, characterized in that, The control module also includes a dynamic output limiting module; The dynamic output limiting module is used to dynamically adjust the upper and lower limits of the output of the inner loop control module according to the theoretical duty cycle in order to limit the sudden changes in the control quantity. The theoretical duty cycle is calculated from the current given target value and the bus voltage.

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