A double-loop adaptive control method and system for zero-flux current transformers
By employing a dual-loop adaptive control method that involves real-time adjustment of the outer loop integrator's limiting and the inner loop's feedforward compensation, the integral saturation and overshoot problems of zero-flux current transformers under dynamic current changes are solved, achieving high-precision and fast-response measurement results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA ELECTRIC POWER RESEARCH INSTITUTE CO LTD
- Filing Date
- 2026-03-03
- Publication Date
- 2026-07-14
AI Technical Summary
Existing zero-flux current transformers suffer from integrator saturation and dynamic overshoot when faced with dynamic current changes, leading to loss of measurement accuracy and system instability.
By acquiring the induced voltage signal of the detection coil in real time, the integral term limit of the outer loop PI regulator is dynamically adjusted using a monotonically decreasing nonlinear function. Combined with feedforward compensation, nonlinear dynamic management of the outer loop integral limit and model feedforward compensation of the inner loop are achieved, forming a dual-loop adaptive control.
It effectively prevents integral saturation, improves the dynamic stability and response speed of the system, maintains high-precision measurement, enhances the system's adaptability and robustness, and reduces transient flux error.
Smart Images
Figure CN122386643A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power system measurement technology, and specifically to a dual-loop adaptive control method and system for zero-flux current transformers. Background Technology
[0002] Zero-flux current transformers eliminate hysteresis and nonlinear effects by introducing feedback current to make the net ampere-turns in the magnetic core zero, thus achieving control over the primary current. I p It offers high-precision, high-bandwidth measurement capabilities. Its performance bottleneck primarily lies in the accuracy and robustness of error signal extraction.
[0003] In a typical dual-core zero-flux structure, such as Figure 2 As shown, two iron cores C1 and C2, made of identical material and of the same size, share the same excitation source, with their primary windings connected in reverse series. When the primary current... I p When = 0, the magnetization of the two iron cores is symmetrical; when I p When the bias magnetic field is 0, the bias magnetic field breaks the symmetry and produces an observable differential signal.
[0004] like Figure 3 As shown, the differential signal is processed to generate a feedback current. The system is balanced when the feedback current magnetomotive force cancels out the primary current magnetomotive force. The primary current can be calculated from the magnitude of the feedback current and the number of coil turns. The core of the signal processing system is a dual-loop architecture consisting of a "voltage / flux outer loop" and a "current inner loop". The outer loop (flux balance loop) calculates the static compensation current reference value based on the detection coil signal, while the inner loop (current tracking loop) is responsible for driving the power amplifier to output this current quickly and accurately.
[0005] Considering that the output capabilities of actuators in practical systems (such as power amplifiers) have physical limits (e.g., voltage and current range), it is necessary to limit the integrator to ensure that the command signal output by the controller does not exceed the actual range that the actuator can respond to, thus preventing the generation of unrealistic control commands. Existing technologies generally employ a strategy of PI controllers combined with fixed integral limiting. This approach performs well under steady-state or small-signal disturbances, but it has serious drawbacks when faced with rapid changes in primary current (such as power system short-circuit faults or power device switching): a sudden increase in outer-loop error causes the integrator to quickly enter deep saturation. The huge integral quantity accumulated during this process is slowly released after the disturbance subsides, causing severe overshoot and oscillation of the compensation current. This directly leads to instantaneous magnetic flux runaway (magnetic flux leakage) in the magnetic core, complete loss of measurement accuracy, and potential damage to subsequent precision detection circuits.
[0006] In general control theory, anti-saturation techniques (such as conditional integration and feedback clamping) and feedforward control have been widely applied. However, directly transplanting existing technologies to zero-flux transformers presents a fundamental mismatch: The outer-loop integrator of a zero-flux system accumulates the integral of the flux error. However, during dynamic processes, the flux error and compensation current are complexly coupled due to core nonlinearity (BH curve), winding distributed parameters, and loop delay. Common output clamping anti-saturation technology is a hysteresis compensation mechanism, typically operating only after the controller output has reached saturation. Therefore, its response is delayed and cannot handle flux imbalance risks at the nanosecond to microsecond level. Furthermore, the directly controllable variable of the system is the secondary compensation current, while the measured primary current is an uncontrollable disturbance input. Traditional feedforward based on the derivative of the setpoint fails here because changes in the primary current cannot be known in advance.
[0007] Therefore, existing solutions inherently contradict dynamic performance and stability. There is an urgent need for a collaborative control mechanism specifically designed for the physical characteristics of zero-flux transformers that can predict and proactively intervene in advance, in order to fundamentally eliminate integral saturation and dynamic overshoot under large signals. Summary of the Invention
[0008] To address the problems in the prior art, this invention provides a dual-loop adaptive control method for zero-flux current transformers, comprising: The induced voltage signal at both ends of the dedicated detection coil of the zero flux transformer is acquired in real time, and the absolute value or effective value of the induced voltage signal is calculated. Based on a pre-designed monotonically decreasing nonlinear function and the absolute or effective value of the induced voltage signal, the output limit value of the integral term in the outer loop PI regulator is dynamically and continuously adjusted to complete the nonlinear dynamic management of the outer loop integral authority. The induced voltage signal is used as a feedforward source to generate a feedforward compensation amount; the feedforward compensation amount is superimposed on the input terminal of the setpoint of the current inner loop regulator to complete the model feedforward compensation of the inner loop. The nonlinear dynamic management of the outer loop integral authority and the model feedforward compensation of the inner loop, through intelligent collaborative control, complete the dual-loop adaptive control of the zero-flux current transformer.
[0009] Furthermore, the induced voltage signal across the dedicated detection coil of the zero flux transformer is acquired in real time, and the absolute or effective value of the induced voltage signal is calculated, including: Real-time acquisition of the induced voltage signal across the dedicated detection coil of the zero flux transformer. The induced voltage signal By using the signal, the corresponding absolute value or effective value can be obtained. V 0_mag .
[0010] Furthermore, based on a pre-designed monotonically decreasing nonlinear function and the absolute or effective value of the induced voltage signal, the output limit value of the integral term in the outer loop PI regulator is dynamically and continuously adjusted to complete the nonlinear dynamic management of the outer loop integral authority, including: Design a monotonically decreasing nonlinear function. ; according to V 0_mag The magnitude of the output limit value of the integral term in the outer loop PI controller is dynamically and continuously adjusted. I lim ,Right now .
[0011] Furthermore, the induced voltage signal is used as a feedforward source to generate a feedforward compensation amount, including: The induced voltage signal V 0( t As a feedforward source, the feedforward source is multiplied by an adjustable feedforward gain coefficient. K ff Generate feedforward compensation amount .
[0012] Furthermore, the nonlinear dynamic management of the outer loop integral authority and the model feedforward compensation of the inner loop, through intelligent collaborative control, complete the dual-loop adaptive control of the zero-flux current transformer, including: When a large disturbance occurs in the system, the nonlinear dynamic management of the outer loop integral authority intelligently constrains the over-adjustment tendency of the outer loop regulator by dynamically tightening the integral limit; the inner loop model feedforward compensation provides the inner loop with additional instantaneous drive commands synchronized with the disturbance through the feedforward channel.
[0013] This invention also provides a dual-loop adaptive control system for zero-flux current transformers, comprising: The signal acquisition module is used to acquire the induced voltage signal at both ends of the dedicated detection coil of the zero flux transformer in real time, and to calculate the absolute value or effective value of the induced voltage signal. The outer loop control module is used to dynamically and continuously adjust the output limit value of the integral term in the outer loop PI regulator according to a pre-designed monotonically decreasing nonlinear function and the absolute or effective value of the induced voltage signal, thereby completing the nonlinear dynamic management of the outer loop integral authority. The inner loop control module is used to use the induced voltage signal as a feedforward source to generate a feedforward compensation amount; the feedforward compensation amount is superimposed on the setpoint input terminal of the current inner loop regulator to complete the model feedforward compensation of the inner loop. The adaptive control module is used for the nonlinear dynamic management of the outer loop integral authority and the model feedforward compensation of the inner loop. Through intelligent collaborative control, it completes the dual-loop adaptive control of the zero-flux current transformer.
[0014] Furthermore, the signal acquisition module includes: The signal acquisition submodule is used to acquire the induced voltage signal across the dedicated detection coil of the zero flux transformer in real time. The induced voltage signal By using the signal, the corresponding absolute value or effective value can be obtained. V 0_mag .
[0015] Furthermore, the outer loop control module includes: The function design submodule is used to design monotonically decreasing nonlinear functions. ; The dynamic adjustment submodule is used to adjust according to... V 0_mag The magnitude of the output limit value of the integral term in the outer loop PI controller is dynamically and continuously adjusted. I lim ,Right now .
[0016] Furthermore, the inner loop control module includes: The feedforward compensation quantity generation submodule is used to generate the induced voltage signal. V 0( t As a feedforward source, the feedforward source is multiplied by an adjustable feedforward gain coefficient. K ff Generate feedforward compensation amount .
[0017] Furthermore, the adaptive control module includes: The intelligent control submodule is used to dynamically manage the nonlinear integral limit of the outer loop when the system experiences a large disturbance, thereby intelligently constraining the over-adjustment tendency of the outer loop regulator by dynamically tightening the integral limit; the model feedforward compensation of the inner loop provides additional instantaneous drive commands synchronized with the disturbance to the inner loop through the feedforward channel.
[0018] This invention provides a dual-loop adaptive control method and system for zero-flux current transformers, which utilizes the physical quantity inherent in the zero-flux current transformer that directly reflects the instantaneous rate of change of magnetic flux—the induced voltage of the detection coil. V 0( t Simultaneously serving as an early warning signal for predicting integral saturation risk and a feedforward signal for implementing rapid compensation, the control strategy is upgraded from passive lag compensation to active prediction and coordination. Attached Figure Description
[0019] Figure 1 This is a flowchart illustrating a dual-loop adaptive control method for a zero-flux current transformer provided by the present invention. Figure 2 This is a schematic diagram of the dual-core differential structure involved in the present invention; Figure 3 This is a schematic diagram of the closed-loop control block diagram involved in the present invention; Figure 4 This invention relates to a schematic diagram of a dual-loop adaptive control principle. Figure 5 This is a schematic diagram of a dual-loop adaptive control system for a zero-flux current transformer provided by the present invention. Detailed Implementation
[0020] Numerous specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.
[0021] Example 1 To address the limitations of existing technologies, such as the inherent hysteresis of general anti-saturation strategies and the impracticality of traditional feedforward schemes due to the lack of effective real-time observation signals, this invention deeply integrates the real-time physical state of the magnetic core into the control system. This achieves predictive limiting of the outer-loop integrator and feedforward of the physical model for the inner loop, thereby ensuring both extremely high static accuracy and transient stability over a wide dynamic range. To achieve the above objectives, this invention provides a dual-loop adaptive control method for zero-flux current transformers, such as... Figure 1 As shown, it includes the following steps: Step S101: Real-time acquisition of the induced voltage signal at both ends of the dedicated detection coil of the zero flux transformer, and calculation of the absolute value or effective value of the induced voltage signal.
[0022] Real-time acquisition of the induced voltage signal across the dedicated detection coil of the zero flux transformer. According to Faraday's law of electromagnetic induction, this voltage is directly and linearly proportional to the rate of change of the instantaneous total magnetic flux Φ within the magnetic core, i.e. ∝ d Φ / dt This signal is the most direct and fastest electrical characterization of the rate at which the magnetic core deviates from its zero flux equilibrium point.
[0023] For the collected Perform necessary signal conditioning (such as filtering to suppress high-frequency noise) and calculate its absolute or effective value. V 0_mag , as an observation of the dynamic intensity and potential saturation risk of a quantitative system.
[0024] Step S102: Based on the pre-designed monotonically decreasing nonlinear function and the absolute or effective value of the induced voltage signal, the output limit value of the integral term in the outer loop PI regulator is dynamically and continuously adjusted to complete the nonlinear dynamic management of the outer loop integral authority.
[0025] Based on the results obtained in the previous step V 0_mag To implement an active anti-saturation strategy for the outer-loop integrator, specifically, a monotonically decreasing nonlinear function is designed. ;according to V 0_mag The magnitude of the output limit value of the integral term in the outer loop PI controller is dynamically and continuously adjusted. I lim ,Right now .
[0026] Its management logic is as follows: Steady-state / small-disturbance mode: when V 0_mag Below the preset safety threshold V th When the system is determined to be in a stable state, the function... Output a generous limiting value. I lim_max Under this constraint, the outer-loop integrator can function effectively, ensuring the system has extremely high static accuracy and the ability to adjust for small errors.
[0027] Large dynamic early warning mode: when V 0_mag Reaching or exceeding the threshold V th At this time, it indicates that the primary current is changing rapidly, the magnetic flux is deviating quickly from the equilibrium point, and there is a high risk of integrator saturation. At this point, the function... Automatically and continuously tighten the output limit value I lim ,and I lim Follow V 0_mag The output limit decreases as the input increases. This mechanism proactively reduces the maximum output limit of the integrator before it enters deep saturation due to a large error signal and begins to accumulate ineffective control quantities. This fundamentally prevents the integral saturation phenomenon under the traditional fixed-limit strategy and achieves proactive protection of "early warning equals limit".
[0028] Step S103: Use the induced voltage signal as a feedforward source to generate a feedforward compensation amount; superimpose the feedforward compensation amount onto the given value input terminal of the current inner loop regulator to complete the model feedforward compensation of the inner loop.
[0029] In parallel, the induced voltage signal As a feedforward source, the feedforward source is multiplied by an adjustable feedforward gain coefficient. K ff Generate feedforward compensation amount This compensation amount is then directly added to the setpoint input of the inner current loop regulator.
[0030] The physical basis of this operation lies in: Proportional to the rate of change of magnetic flux d Φ / dt According to the system model, the ideal compensation current required to offset sudden changes in the primary current changes in a rate proportional to the flux change. Therefore, the feedforward path essentially injects the real-time dynamic information of the magnetic core directly and rapidly into the inner loop (current tracking loop) in the form of a small component (or trend) of the compensation current. This effectively bypasses the inherent computational and response delay of the outer loop PI regulator, providing the power amplifier stage with a "predictive" drive command synchronized with the disturbance trend, thereby greatly improving the system's tracking speed and dynamic response capability to rapidly changing currents.
[0031] In step S104, the nonlinear dynamic management of the outer loop integral authority and the model feedforward compensation of the inner loop are combined through intelligent collaborative control to complete the dual-loop adaptive control of the zero flux current transformer.
[0032] This invention enables intelligent collaboration between the outer and inner loops, rather than allowing them to work independently.
[0033] Dual-loop adaptive control principle, such as Figure 4 As shown, when the system encounters a large disturbance, the nonlinear dynamic management of the outer loop integral limit intelligently constrains the "over-adjustment" tendency of the outer loop regulator by dynamically tightening the integral limit, preventing it from failing due to saturation or even producing negative effects.
[0034] At the same time, the inner loop's model feedforward compensation provides the inner loop with additional, disturbance-synchronized instantaneous drive commands through the feedforward channel, enabling it to still achieve strong and rapid response capabilities even when the outer loop output is constrained.
[0035] This collaborative mechanism, where the outer loop actively yields power to prevent saturation while the inner loop achieves fast feedforward response, transforms the dual-loop control system from a traditional cascade structure that may contradict each other during dynamic processes into an organic whole with consistent goals and intelligent dynamic power allocation. Ultimately, the system, while ensuring absolute stability and no overshoot, pushes its dynamic response performance close to the physical limits of the power stage hardware itself.
[0036] Example 2 With a rated current The present invention will be described in detail using a zero-flux current transformer with a nanocrystalline alloy core as an example.
[0037] 1. System Architecture and Signal Acquisition like Figure 2 As shown, the system hardware includes: a detection coil, a signal conditioning circuit (including a low-pass filter and a programmable gain amplifier), an analog-to-digital converter (ADC), a digital processor (such as a DSP or FPGA), a digital-to-analog converter (DAC), a power amplifier, and a feedback coil. The core innovation lies in the processor's control algorithm.
[0038] Detection coil induced voltage V 0( t After conditioning, the signal is fed into the ADC. In the digital domain, its absolute value is first calculated and then passed through a first-order low-pass filter to suppress switching noise, resulting in the amplitude signal used for decision-making. V 0_mag At the same time, the original The signal is also sent to the feedforward channel. The induced voltage signal... In practice, it can be the direct voltage across the detection coil, or it can be an equivalent electrical signal that maintains a definite functional relationship with the coil after linear conditioning such as scaling and level shifting.
[0039] 2. Nonlinear dynamic amplitude limiting function Design and optimization function The design needs to achieve an optimal balance between "anti-saturation strength" and "steady-state accuracy loss". This invention recommends using "piecewise linear decrease" as an optimization trade-off.
[0040] Threshold setting: Through experiments, measurements were taken at the maximum allowable threshold. (e.g. 200) )Down Set the first threshold. This value is sufficient to distinguish system noise from real large disturbances.
[0041] Limiting logic: when , .
[0042] when , from linearly decreasing to .
[0043] when , It enters a strong damping protection state.
[0044] Hysteresis design: To avoid oscillations near the threshold, set approximately... The hysteresis band. That is... V 0_mag Need to be reduced to The current limit value will then be restored to the previous value. .
[0045] In addition to piecewise linear functions, the nonlinear functions Other monotonically decreasing forms can also be used. For example, when using an exponential decay form, it can be defined as... , where k is the attenuation coefficient. When using the Sigmoid function, it can be defined as in The intermediate threshold, The steepness coefficient can be determined through system simulation optimization.
[0046] 3. Feedforward gain Adjustment Feedforward gain There exists a theoretical optimal value, which is related to the physical model of the current transformer. The theoretical initial value can be derived as follows: in, For the equivalent inductance of the feedback coil, To detect the number of coil turns, This is the current sampling resistor. In practice, it can be used... Fine-tune the step response test within ±30% range: gradually increase until The initial peak value is suppressed to the greatest extent, and the system does not experience high-frequency oscillations. This is the optimal value for engineering.
[0047] This embodiment is merely an example, and the threshold can be adjusted according to different hardware platforms, all of which fall within the protection scope of this invention.
[0048] Example 3 Based on the same inventive concept, this invention also provides a dual-loop adaptive control system for zero-flux current transformers, such as... Figure 5 As shown, it includes: The signal acquisition module 510 is used to acquire the induced voltage signal at both ends of the dedicated detection coil of the zero flux transformer in real time, and to calculate the absolute value or effective value of the induced voltage signal. The outer loop control module 520 is used to dynamically and continuously adjust the output limit value of the integral term in the outer loop PI regulator according to a pre-designed monotonically decreasing nonlinear function and the absolute or effective value of the induced voltage signal, thereby completing the nonlinear dynamic management of the outer loop integral authority. The inner loop control module 530 is used to use the induced voltage signal as a feedforward source to generate a feedforward compensation amount; and to superimpose the feedforward compensation amount onto the given value input terminal of the current inner loop regulator to complete the model feedforward compensation of the inner loop. The adaptive control module 540 is used for the nonlinear dynamic management of the outer loop integral authority and the model feedforward compensation of the inner loop. Through intelligent collaborative control, it completes the dual-loop adaptive control of the zero flux current transformer.
[0049] Furthermore, the signal acquisition module includes: The signal acquisition submodule is used to acquire the induced voltage signal across the dedicated detection coil of the zero flux transformer in real time. The induced voltage signal By using the signal, the corresponding absolute value or effective value can be obtained. V 0_mag .
[0050] Furthermore, the outer loop control module includes: The function design submodule is used to design monotonically decreasing nonlinear functions. ; The dynamic adjustment submodule is used to adjust according to... V 0_mag The magnitude of the output limit value of the integral term in the outer loop PI controller is dynamically and continuously adjusted. I lim ,Right now .
[0051] Furthermore, the inner loop control module includes: The feedforward compensation quantity generation submodule is used to generate the induced voltage signal. V 0( t As a feedforward source, the feedforward source is multiplied by an adjustable feedforward gain coefficient. K ff Generate feedforward compensation amount .
[0052] Furthermore, the adaptive control module includes: The intelligent control submodule is used to dynamically manage the nonlinear integral limit of the outer loop when the system experiences a large disturbance, thereby intelligently constraining the over-adjustment tendency of the outer loop regulator by dynamically tightening the integral limit; the model feedforward compensation of the inner loop provides additional instantaneous drive commands synchronized with the disturbance to the inner loop through the feedforward channel.
[0053] The present invention provides a dual-loop adaptive control method and system for zero-flux current transformers, the advantages of which are as follows: The problem of integral saturation and dynamic overshoot has been solved: by using a dynamic limiting mechanism based on the rate of change of magnetic flux, deep saturation of the integrator can be effectively prevented, thereby avoiding severe overshoot of the compensation current and system oscillation caused by it, and significantly improving the dynamic stability and reliability of the system.
[0054] Significant improvements in dynamic response speed and accuracy have been achieved: By introducing a feedforward compensation path derived from the core's own state, the system can predictively compensate for rapidly changing currents, significantly shortening response delay and accelerating the recovery process of magnetic flux balance. Simultaneously, dynamic access control enables the system to maintain excellent tracking accuracy even under severe disturbances, greatly reducing transient magnetic flux errors.
[0055] The invention significantly enhances the system's adaptability and robustness: the core parameters of the control strategy are directly related to the real-time physical state of the magnetic core, rather than fixed thresholds. This gives the control system inherent intelligent adjustment characteristics, making it more adaptable to uncertainties such as changes in operating point, fluctuations in ambient temperature, and drift in component parameters, thereby ensuring the consistency and long-term stability of the product's performance throughout its entire lifecycle.
[0056] It possesses excellent engineering practicality and economy: The proposed method fully utilizes the inherent detection signal within the zero-flux transformer system, eliminating the need for additional sensors or complex hardware. Performance leaps are primarily achieved through upgrades and optimizations of the control algorithm. This solution is easily deployed and integrated onto existing digital processors (such as DSPs and FPGAs) or microcontroller platforms, resulting in low implementation costs and significant commercial potential.
[0057] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied 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.
[0058] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.
[0059] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.
[0060] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.
[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of the claims of the present invention.
Claims
1. A dual-loop adaptive control method for zero-flux current transformers, characterized in that, include: The induced voltage signal at both ends of the dedicated detection coil of the zero flux transformer is acquired in real time, and the absolute value or effective value of the induced voltage signal is calculated. Based on a pre-designed monotonically decreasing nonlinear function and the absolute or effective value of the induced voltage signal, the output limit value of the integral term in the outer loop PI regulator is dynamically and continuously adjusted to complete the nonlinear dynamic management of the outer loop integral authority. The induced voltage signal is used as a feedforward source to generate a feedforward compensation amount; the feedforward compensation amount is superimposed on the input terminal of the setpoint of the current inner loop regulator to complete the model feedforward compensation of the inner loop. The nonlinear dynamic management of the outer loop integral authority and the model feedforward compensation of the inner loop, through intelligent collaborative control, complete the dual-loop adaptive control of the zero-flux current transformer.
2. The method according to claim 1, characterized in that, The system acquires the induced voltage signal across the dedicated detection coil of the zero-flux transformer in real time and calculates the absolute or effective value of the induced voltage signal, including: Real-time acquisition of the induced voltage signal across the dedicated detection coil of the zero flux transformer. The induced voltage signal By using the signal, the corresponding absolute value or effective value can be obtained. V 0_mag .
3. The method according to claim 1, characterized in that, Based on a pre-designed monotonically decreasing nonlinear function and the absolute or effective value of the induced voltage signal, the output limit value of the integral term in the outer loop PI regulator is dynamically and continuously adjusted to complete the nonlinear dynamic management of the outer loop integral authority, including: Design a monotonically decreasing nonlinear function. ; according to V 0_mag The magnitude of the output limit value of the integral term in the outer loop PI controller is dynamically and continuously adjusted. I lim ,Right now .
4. The method according to claim 1, characterized in that, Using the induced voltage signal as a feedforward source, a feedforward compensation quantity is generated, including: The induced voltage signal As a feedforward source, the feedforward source is multiplied by an adjustable feedforward gain coefficient. K ff Generate feedforward compensation amount .
5. The method according to claim 1, characterized in that, The nonlinear dynamic management of the outer loop integral authority and the model feedforward compensation of the inner loop, through intelligent collaborative control, complete the dual-loop adaptive control of the zero-flux current transformer, including: When a large disturbance occurs in the system, the nonlinear dynamic management of the outer loop integral authority intelligently constrains the over-adjustment tendency of the outer loop regulator by dynamically tightening the integral limit; the inner loop model feedforward compensation provides the inner loop with additional instantaneous drive commands synchronized with the disturbance through the feedforward channel.
6. A dual-loop adaptive control system for zero-flux current transformers, characterized in that, include: The signal acquisition module is used to acquire the induced voltage signal at both ends of the dedicated detection coil of the zero flux transformer in real time, and to calculate the absolute value or effective value of the induced voltage signal. The outer loop control module is used to dynamically and continuously adjust the output limit value of the integral term in the outer loop PI regulator according to a pre-designed monotonically decreasing nonlinear function and the absolute or effective value of the induced voltage signal, thereby completing the nonlinear dynamic management of the outer loop integral authority. The inner loop control module is used to use the induced voltage signal as a feedforward source to generate a feedforward compensation amount; the feedforward compensation amount is superimposed on the setpoint input terminal of the current inner loop regulator to complete the model feedforward compensation of the inner loop. The adaptive control module is used for the nonlinear dynamic management of the outer loop integral authority and the model feedforward compensation of the inner loop. Through intelligent collaborative control, it completes the dual-loop adaptive control of the zero-flux current transformer.
7. The system according to claim 6, characterized in that, The signal acquisition module includes: The signal acquisition submodule is used to acquire the induced voltage signal across the dedicated detection coil of the zero flux transformer in real time. The induced voltage signal By using the signal, the corresponding absolute value or effective value can be obtained. V 0_mag .
8. The system according to claim 6, characterized in that, The outer loop control module includes: The function design submodule is used to design monotonically decreasing nonlinear functions. ; The dynamic adjustment submodule is used to adjust according to... V 0_mag The magnitude of the output limit value of the integral term in the outer loop PI controller is dynamically and continuously adjusted. I lim ,Right now .
9. The system according to claim 6, characterized in that, The inner loop control module includes: The feedforward compensation quantity generation submodule is used to generate the induced voltage signal. V 0( t As a feedforward source, the feedforward source is multiplied by an adjustable feedforward gain coefficient. K ff Generate feedforward compensation amount .
10. The system according to claim 6, characterized in that, The adaptive control module includes: The intelligent control submodule is used to dynamically manage the nonlinear integral limit of the outer loop when the system experiences a large disturbance, thereby intelligently constraining the over-adjustment tendency of the outer loop regulator by dynamically tightening the integral limit; the model feedforward compensation of the inner loop provides additional instantaneous drive commands synchronized with the disturbance to the inner loop through the feedforward channel.