A current closed loop control circuit

Abstract

This application relates to the field of current control technology and discloses a current closed-loop control circuit, including a current sensing module, a signal conditioning module, an error amplification module, a PI control module, a PWM modulation module, and a power drive module. In this application, the current sensing module captures the current signal, the signal conditioning module suppresses high-frequency noise, the error amplification module compares with a reference current, the PI control module dynamically adjusts the proportional-integral parameters to adapt to high-speed scenarios, the PWM modulation module generates a high-frequency drive signal, and the power drive module achieves stable high-voltage, high-current output. Thus, hardware-based computation improves real-time performance, signal conditioning and power protection enhance anti-interference capabilities, PI dynamic parameter adaptation achieves scenario self-matching, and closed-loop feedback ensures current control accuracy. This effectively solves problems such as software delay, resource consumption, and complex hardware design in high-speed dynamic control such as magnetic levitation, providing a full-link hardware optimization architecture for high-precision current control while maintaining reliability and engineering practicality.

Description

Technical Field

[0001] This application relates to the field of current control technology, and in particular to a current closed-loop control circuit. Background Technology

[0002] In existing technologies, PI control (proportional-integral control) for current closed-loop control is mostly implemented in software. However, this software implementation suffers from problems such as slow control speed, poor real-time performance, susceptibility to interference from the software operating environment, and high computational resource consumption, making it difficult to meet the needs of high-speed dynamic control scenarios. For example, in magnetic levitation control systems, its high-speed dynamic control performance is significantly limited.

[0003] To address these issues, related technologies have attempted to implement PI control in hardware to improve the system's real-time performance and anti-interference capabilities. However, implementing high-speed PI control in hardware presents challenges such as complex circuit layout and wiring design, and difficulties in ensuring signal integrity. Furthermore, the hardware design requires precise algorithm matching to specific application scenarios, demanding high adaptability and increasing design complexity.

[0004] Furthermore, when implementing high-speed PI control based on hardware amplifiers, multiple key factors need to be comprehensively considered, including amplifier performance parameters, circuit topology, and compensation network design. Moreover, to achieve real-time adjustment and optimization of PI parameters, it is necessary to combine hardware amplifiers with digital signal processing technology. This involves dynamically adjusting amplifier parameters such as gain and integration time through digital circuits to improve the system's adaptive capability. This integration process presents significant technical challenges in engineering applications.

[0005] In addition, high-speed PI control systems need to work closely with various sensors to achieve accurate measurement and control of a variety of physical quantities, which further increases the complexity of the system design.

[0006] In summary, existing current closed-loop control schemes based on software or hardware implementation all have many shortcomings, and a new current closed-loop control technology is urgently needed to solve the above problems. Utility Model Content

[0007] The purpose of this application is to provide a current closed-loop control circuit to solve the technical problems mentioned in the background art.

[0008] To achieve the above objectives, this application discloses the following technical solution: a current closed-loop control circuit, comprising: a current sensing module, a signal conditioning module, an error amplification module, a PI control module, a PWM modulation module, and a power drive module;

[0009] The measurement output terminal of the current sensing module is connected to the input terminal of the signal conditioning module. The output terminal of the signal conditioning module is connected to the input terminal of the error amplification module. The output terminal of the error amplification module is connected to the input terminal of the PI control module. The output terminal of the PI control module is connected to the input terminal of the PWM modulation module. The output terminal of the PWM modulation module is connected to the input terminal of the power drive module. The output terminal of the power drive module is connected to the input terminal of the current sensing module.

[0010] Preferably, the current sensing module includes a current sensor U36, a capacitor C157, a capacitor C159, and a power connector O9.

[0011] Pins 1, 2, and 3 of the current sensor U36 are all connected to the output terminal of the power drive module; pins 4, 5, and 6 of the current sensor U36 are all connected to the positive terminal of the power connector O9, and the negative terminal of the power connector O9 is connected to the output terminal of the power drive module; pin 7 of the current sensor U36 and one end of the capacitor C159 are both connected to -12V, and the other end of the capacitor C159 is grounded; pin 8 of the current sensor U36 and one end of the capacitor C157 are both connected to +12V, and the other end of the capacitor C157 is grounded; pin 9 of the current sensor U36 is the measurement output terminal, which outputs signal U36-M to the input terminal of the signal conditioning module.

[0012] Preferably, the signal conditioning module includes a capacitor C158, a resistor R306, and a resistor R304;

[0013] One end of capacitor C158 and one end of resistor R306 are both connected to the measurement output terminal of the current sensing module to receive the signal U36-M; one end of capacitor C158 and one end of resistor R306 are also connected to the input terminal of the error amplification module; the other end of capacitor C158, the other end of resistor R306 and one end of resistor R304 are all grounded, and the other end of resistor R304 is connected to the input terminal of the error amplification module.

[0014] Preferably, the error amplification module includes operational amplifier U34C, resistor R305, resistor R291, resistor R292, operational amplifier U34D, resistor R285, and resistor R282;

[0015] The non-inverting input terminal of operational amplifier U34C is connected to one end of capacitor C158 and one end of resistor R306. The non-inverting input terminal of operational amplifier U34C is connected to the other end of resistor R304 and one end of resistor R305. The output terminal of operational amplifier U34C and the other end of resistor R305 are both connected to one end of resistor R285. One end of resistor R291 receives the reference current signal U4-1OUT. The other ends of resistor R291 and one end of resistor R292 are both connected to the non-inverting input terminal of operational amplifier U34D. The other end of resistor R292 is grounded. The other end of resistor R285 and one end of resistor R282 are both connected to the non-inverting input terminal of operational amplifier U34D. The other end of resistor R282 and the output terminal of operational amplifier U34D are both connected to the input terminal of the PI control module.

[0016] Preferably, the PI control module includes resistor R293, resistor R286, operational amplifier U34B, resistor R281, capacitor C145, resistor R294, resistor R289, inverter U34A, capacitor C147, capacitor C146 and resistor R283.

[0017] One end of resistor R293 is grounded, and the other end of resistor R293 is connected to the non-inverting input terminal of operational amplifier U34B. One end of resistor R286 is connected to the other end of resistor R282 and the output terminal of operational amplifier U34D. The other end of resistor R286, one end of resistor R281, and one end of capacitor C145 are all connected to the non-inverting input terminal of operational amplifier U34B. One end of resistor R289, the other end of resistor R281, and the other end of capacitor C145 are all connected to the output terminal of operational amplifier U34B. The other end of resistor R289 and resistor R283... One end of each resistor is connected to the negative input terminal of the inverter U34A, and the other end of the resistor R283 is connected to the input terminal of the PWM modulation module; one end of the resistor R294 is grounded, and the other end of the resistor R294 is connected to the positive input terminal of the inverter U34A; the positive power supply pin of the inverter U34A and one end of the capacitor C147 are both connected to +12V, and the other end of the capacitor C147 is grounded; the negative power supply pin of the inverter U34A and one end of the capacitor C146 are both connected to -12V, and the other end of the capacitor C146 is grounded; the output terminal of the inverter U34A is connected to the input terminal of the PWM modulation module.

[0018] Preferably, the PWM modulation module includes resistors R278, R287, R280, and R290, comparator U30C, operational amplifier U30D, resistors R277, R284, R279, and R288, diode D54, diode D55, resistor R295, capacitor C148, and capacitor C152.

[0019] One end of resistor R278 is connected to the output of inverter U34A, and the other end of resistor R278 is connected to the non-inverting input of comparator U30C. One end of resistors R280 and R290 both receive signal U3-1OUT. The other end of resistor R280 is connected to the inverting input of comparator U30C, and the other end of resistor R290 is connected to the inverting input of operational amplifier U30D. One end of resistor R287 is connected to the other end of resistor R283, and the other end of resistor R287 is connected to the non-inverting input of operational amplifier U30D. One end of resistors R277 and R279 are both connected to the output of comparator U30C, and the other end of resistor R277 is connected to +12V. The other end of resistor R279 and the cathode of diode D54 are both connected to one end of resistor R295. The anode of diode D54 is grounded. The other end of resistor R295 is connected to one end of capacitor C148 to output signal U35-INA. The other end of capacitor C148 is grounded. One end of resistor R284 and one end of resistor R288 are both connected to the output terminal of operational amplifier U30D. The other end of resistor R284 is connected to +12V. The other end of resistor R288 and the cathode of diode D55 are both connected to one end of resistor R299. The anode of diode D55 is grounded. The other end of resistor R299 is connected to one end of capacitor C152 to output signal U35-INB. The other end of capacitor C152 is grounded.

[0020] Preferably, the power drive module includes a gate driver U35, MOSFETs Q17 and Q18, capacitors C154 and C153, diodes D56 and C149, resistors R303 and C155, resistors R297 and D59, resistors R301, R300, R302, R298, diodes D58 and D57, and a polarized capacitor C21.

[0021] Pins 3 and 8 of the gate driver U35 and one end of capacitor C154 are all connected to +12V, and the other end of capacitor C154 is grounded. Pin 1 of the gate driver U35 receives the signal U35-INA, and pin 2 of the gate driver U35 receives the signal U35-INB. Pin 6 of the gate driver U35 and one end of capacitor C153 are both connected to +12V, and the other end of capacitor C153 and pin 4 of the gate driver U35 are grounded. Pin 16 of the gate driver U35 and one end of capacitor C149... All terminals are connected to the cathode of diode D56, and the anode of diode D56 is connected to VO+. The other end of capacitor C149 and pin 14 of gate driver U35 are both connected to one end of resistor R303, and the other end of resistor R303 is connected to V-. The other end of capacitor C149, pin 14 of gate driver U35, one end of resistor R303, and the cathode of diode D59 are all connected to one end of resistor R300, and the anode of diode D59 is connected to V-. The other end of resistor R300, the cathode of diode D56, and the cathode of gate driver U35 are all connected to one end of resistor R300. One end of resistor R298, the cathode of diode D58, and the source of MOSFET Q17 are connected to pins 1, 2, and 3 of current sensor U36. Pin 15 of gate driver U35 is connected to one end of resistor R297. The other ends of R297 and R298 are both connected to the gate of MOSFET Q17. The drain of MOSFET Q17 and the positive terminal of polarized capacitor C21 are both connected to HV, and the negative terminal of polarized capacitor C21 is connected to V-. Pin 11 of gate driver U35 and capacitor C... One end of capacitor C155 is connected to VO+. Pin 9 of gate driver U35, the other end of capacitor C155, and one end of resistor R302 are all connected to the source of MOSFET Q18. Pin 10 of gate driver U35 is connected to one end of resistor R301. The other ends of resistor R301 and resistor R302 are both connected to the gate of MOSFET Q18. The negative terminal of power connector O9 and the drain of MOSFET Q18 are both connected to the positive terminal of diode D57. The negative terminal of diode D57 is connected to HV.

[0022] Beneficial effects: The current closed-loop control circuit of this application accurately captures the current signal through the current sensing module, suppresses high-frequency noise through the signal conditioning module, compares the reference current with high precision through the error amplification module, dynamically adjusts the proportional-integral parameters of the PI control module to adapt to high-speed scenarios through the PWM modulation module, generates a high-frequency drive signal through the PWM modulation module, and achieves stable high-voltage and high-current output through the power drive module in conjunction with the protection diodes / capacitors. This breaks through the bottleneck of traditional software PI control, improves real-time performance through hardware-based calculation, enhances anti-interference capability through signal conditioning and power protection, achieves scene self-matching through PI dynamic parameter adaptation, and ensures current control accuracy through closed-loop feedback. It effectively solves the problems of software delay, resource consumption, and complex hardware design in high-speed dynamic control such as magnetic levitation, and provides a full-link hardware optimization architecture for high-precision current control while combining reliability and engineering practicality. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0024] Figure 1 The circuit of the current closed-loop control circuit provided in the embodiments of this application Figure 1 ;

[0025] Figure 2 The circuit of the current closed-loop control circuit provided in the embodiments of this application Figure 2 . Detailed Implementation

[0026] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0027] In this document, the term "comprising" is intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus 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 apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0028] Currently, most control systems are implemented using software-based PI (proportional-integral) control, which suffers from slow control speed, poor real-time performance, susceptibility to interference from the software operating environment, and high computational resource consumption. To address the high-speed dynamic control challenges of magnetic levitation control systems, hardware-based PI control is employed to improve the system's real-time performance and anti-interference capabilities.

[0029] like Figure 1 and Figure 2 As shown, this embodiment discloses a current closed-loop control circuit, including: a current sensing module, a signal conditioning module, an error amplification module, a PI control module, a PWM modulation module, and a power drive module;

[0030] The measurement output terminal of the current sensing module is connected to the input terminal of the signal conditioning module. The output terminal of the signal conditioning module is connected to the input terminal of the error amplification module. The output terminal of the error amplification module is connected to the input terminal of the PI control module. The output terminal of the PI control module is connected to the input terminal of the PWM modulation module. The output terminal of the PWM modulation module is connected to the input terminal of the power drive module. The output terminal of the power drive module is connected to the input terminal of the current sensing module.

[0031] Specifically, the current sensing module includes a current sensor U36, capacitor C157, capacitor C159, and power connector O9.

[0032] Pins 1, 2, and 3 of current sensor U36 are all connected to the output of the power drive module; pins 4, 5, and 6 of current sensor U36 are all connected to the positive terminal of power connector O9, and the negative terminal of power connector O9 is connected to the output of the power drive module; pin 7 of current sensor U36 and one end of capacitor C159 are both connected to -12V, and the other end of capacitor C159 is grounded; pin 8 of current sensor U36 and one end of capacitor C157 are both connected to +12V, and the other end of capacitor C157 is grounded; pin 9 of current sensor U36 is the measurement output terminal, which outputs signal U36-M to the input of the signal conditioning module.

[0033] In this embodiment, the current sensor U36 is selected as LAH25-N to output the feedback signal U36-M. A closed loop is formed based on the signal conditioning module, error amplification module, PI control module, PWM modulation module and power drive module to realize current tracking.

[0034] Specifically, the signal conditioning module includes capacitor C158, resistor R306, and resistor R304;

[0035] One end of capacitor C158 and one end of resistor R306 are both connected to the measurement output terminal of the current sensing module to receive signal U36-M; one end of capacitor C158 and one end of resistor R306 are also connected to the input terminal of the error amplifier module; the other end of capacitor C158, the other end of resistor R306 and one end of resistor R304 are all grounded, and the other end of resistor R304 is connected to the input terminal of the error amplifier module.

[0036] In this embodiment, the signal conditioning module consists of a first-order low-pass filter composed of a resistor R306 (150Ω) and a capacitor C158 (10nF) to filter out high-frequency noise from the signal U36-M of the actual current collected by the current sensor LAH25-NP.

[0037] Specifically, the error amplification module includes operational amplifier U34C, resistor R305, resistor R291, resistor R292, operational amplifier U34D, resistor R285, and resistor R282;

[0038] The non-inverting input of operational amplifier U34C is connected to one end of capacitor C158 and one end of resistor R306. The negative-inverting input of operational amplifier U34C is connected to the other end of resistor R304 and one end of resistor R305. The output of operational amplifier U34C and the other end of resistor R305 are both connected to one end of resistor R285. One end of resistor R291 receives the reference current signal U4-1OUT. The other ends of resistor R291 and one end of resistor R292 are both connected to the non-inverting input of operational amplifier U34D. The other end of resistor R292 is grounded. The other end of resistor R285 and one end of resistor R282 are both connected to the negative-inverting input of operational amplifier U34D. The other end of resistor R282 and the output of operational amplifier U34D are both connected to the input of the PI control module.

[0039] In this implementation, the error amplification module uses an operational amplifier U34C to form a non-inverting amplifier. The filtered signal is amplified by 19 / 3 times and then input together with the reference current signal U4-1OUT to the operational amplifier U34D. The difference is amplified by 6.1 times through a precision resistor network with a resistor network matching accuracy of 0.1%.

[0040] Specifically, the PI control module includes resistor R293, resistor R286, operational amplifier U34B, resistor R281, capacitor C145, resistor R294, resistor R289, inverter U34A, capacitor C147, capacitor C146 and resistor R283.

[0041] One end of resistor R293 is grounded, and the other end of resistor R293 is connected to the non-inverting input of operational amplifier U34B. One end of resistor R286 is connected to the other end of resistor R282 and the output of operational amplifier U34D. The other end of resistor R286, one end of resistor R281, and one end of capacitor C145 are all connected to the non-inverting input of operational amplifier U34B. One end of resistor R289, the other end of resistor R281, and the other end of capacitor C145 are all connected to the output of operational amplifier U34B. The other end of resistor R289 and one end of resistor R283... All terminals are connected to the negative input terminal of inverter U34A. The other end of resistor R283 is connected to the input terminal of the PWM modulation module. One end of resistor R294 is grounded, and the other end of resistor R294 is connected to the positive input terminal of inverter U34A. The positive power supply pin of inverter U34A and one end of capacitor C147 are both connected to +12V, and the other end of capacitor C147 is grounded. The negative power supply pin of inverter U34A and one end of capacitor C146 are both connected to -12V, and the other end of capacitor C146 is grounded. The output terminal of inverter U34A is connected to the input terminal of the PWM modulation module.

[0042] In this implementation, the PI control module uses an integrator composed of operational amplifier U34B (with a time constant set by resistor R281 = 200kΩ and capacitor C145 = 390pF) and an inverter composed of inverter U34A to output a compensation signal to the PWM modulation module. Furthermore, the integration time constant τ = 78us (R315 × C160), and the output impedance of inverter U34A is 50Ω to ensure impedance matching with the PWM modulation module.

[0043] Specifically, the PWM modulation module includes resistors R278, R287, R280, and R290, comparator U30C, operational amplifier U30D, resistors R277, R284, R279, and R288, diodes D54 and D55, resistor R295, capacitors C148 and C152;

[0044] One end of resistor R278 is connected to the output of inverter U34A, and the other end is connected to the non-inverting input of comparator U30C. One end of resistors R280 and R290 both receive signal U3-1OUT; the other end of resistor R280 is connected to the inverting input of comparator U30C; the other end of resistor R290 is connected to the inverting input of operational amplifier U30D; one end of resistor R287 is connected to the other end of resistor R283, and the other end of resistor R287 is connected to the non-inverting input of operational amplifier U30D; one end of resistors R277 and R279 are both connected to the output of comparator U30C, and the other end of resistor R277 is connected to +12V. The other end of resistor R279 and the cathode of diode D54 are both connected to one end of resistor R295. The anode of diode D54 is grounded. The other end of resistor R295 is connected to one end of capacitor C148 to output signal U35-INA. The other end of capacitor C148 is grounded. One end of resistor R284 and one end of resistor R288 are both connected to the output terminal of operational amplifier U30D. The other end of resistor R284 is connected to +12V. The other end of resistor R288 and the cathode of diode D55 are both connected to one end of resistor R299. The anode of diode D55 is grounded. The other end of resistor R299 is connected to one end of capacitor C152 to output signal U35-INB. The other end of capacitor C152 is grounded.

[0045] In this embodiment, the PWM modulation module generates a square wave with adjustable duty cycle by passing the compensation signal and the 20kHz triangular wave of U3-1OUT through comparator U30C.

[0046] Specifically, the power drive module includes gate driver U35, MOSFET Q17, MOSFET Q18, capacitor C154, capacitor C153, diode D56, capacitor C149, resistor R303, capacitor C155, resistor R297, diode D59, resistor R301, resistor R300, resistor R302, resistor R298, diode D58, diode D57, and polarized capacitor C21;

[0047] Pins 3 and 8 of gate driver U35 and one end of capacitor C154 are connected to +12V, while the other end of capacitor C154 is grounded. Pin 1 of gate driver U35 receives signal U35-INA, and pin 2 of gate driver U35 receives signal U35-INB. Pin 6 of gate driver U35 and one end of capacitor C153 are both connected to +12V, while the other end of capacitor C153 and pin 4 of gate driver U35 are grounded. Pin 16 of gate driver U35 and one end of capacitor C149... All terminals are connected to the cathode of diode D56, and the anode of diode D56 is connected to VO+. The other end of capacitor C149 and pin 14 of gate driver U35 are connected to one end of resistor R303, and the other end of resistor R303 is connected to V-. The other end of capacitor C149, pin 14 of gate driver U35, one end of resistor R303, and the cathode of diode D59 are all connected to one end of resistor R300, and the anode of diode D59 is connected to V-. The other end of resistor R300 and resistor R... One end of 298, the cathode of diode D58, and the source of MOSFET Q17 are connected to pins 1, 2, and 3 of current sensor U36; pin 15 of gate driver U35 is connected to one end of resistor R297, and the other ends of R297 and R298 are both connected to the gate of MOSFET Q17. The drain of MOSFET Q17 and the positive terminal of polarized capacitor C21 are both connected to HV, and the negative terminal of polarized capacitor C21 is connected to V-; pin 11 of gate driver U35 and capacitor C15... One end of pin 5 is connected to VO+. Pin 9 of gate driver U35, the other end of capacitor C155, and one end of resistor R302 are all connected to the source of MOSFET Q18. Pin 10 of gate driver U35 is connected to one end of resistor R301. The other ends of resistor R301 and resistor R302 are both connected to the gate of MOSFET Q18. The negative terminal of power connector O9 and the drain of MOSFET Q18 are both connected to the positive terminal of diode D57. The negative terminal of diode D57 is connected to HV.

[0048] In this embodiment, the power drive module controls the alternating conduction of either half-bridge MOSFET Q17 or MOSFET Q18 via gate driver U35 (model UCC21520), ultimately forming a closed loop through the feedback from current sensor LAH25-N to U36-M, achieving current tracking. Furthermore, the current sensor LAH25-NP has a transfer ratio of 1:2000, and a parallel RC filter network (R306=150Ω / C158=10nF) on the secondary side suppresses high-frequency interference. After power-on, the reference current signal U4-1OUT and the actual current signal, filtered by resistor R306 and capacitor C158 and amplified by operational amplifier U34C, are differentially amplified by inverter U34D. The resulting error signal is used by integrator U34B and inverter U34A to generate a compensation voltage, which is compared with the triangular wave of U3-1OUT to generate a PWM wave. LAH25-NP detects the output current in real time and feeds it back to U36-M, forming a closed-loop control. When the load changes abruptly, the circuit can complete the current adjustment within 100μs with a ripple coefficient of <0.5%, making it particularly suitable for magnetic levitation bearing systems that require millimeter-level position control.

[0049] In practical applications, this embodiment processes the error signal in real time based on a preset proportional coefficient and integral time constant. It eliminates software calculation delays through pure hardware circuitry and outputs a drive signal to the power execution unit, thereby achieving high-precision tracking of the reference current by the actual current within milliseconds. In a five-degree-of-freedom active magnetic bearing system, this embodiment precisely controls the excitation current in the electromagnetic coils through closed-loop regulation based on a hardware PI controller, ensuring that the generated Lorentz force can balance the dynamic load of the rotor in real time. Specifically, when the rotor experiences radial or axial displacement due to high-speed rotation, the system uses a comparator circuit composed of a high-gain operational amplifier to detect the error signal between the reference current and the actual coil current in real time. After processing by the hardware PI controller, the error signal is output to the power drive module to dynamically adjust the current intensity of each degree-of-freedom electromagnetic coil. This fast-response mechanism based on pure hardware circuitry enables the generated Lorentz force vector to accurately counteract centrifugal force and external disturbances, stabilizing the rotor within a sub-micron precision range. This achieves dynamic stability of the rotor's suspension position in the five-degree-of-freedom active magnetic bearing system, solving the oscillation and instability problems caused by delays in traditional software control schemes.

[0050] In summary, the current closed-loop control circuit of this embodiment features a current sensing module that accurately captures the current signal, a signal conditioning module that suppresses high-frequency noise, an error amplification module that accurately compares the reference current, a PI control module that dynamically adjusts the proportional-integral parameters to adapt to high-speed scenarios, a PWM modulation module that generates a high-frequency drive signal, and a power drive module that works with protection diodes / capacitors to achieve stable high-voltage, high-current output. This overcomes the bottlenecks of traditional software PI control, improves real-time performance through hardware-based computation, enhances anti-interference capabilities through signal conditioning and power protection, achieves scenario self-matching through dynamic PI parameter adaptation, and ensures current control accuracy through closed-loop feedback. It effectively solves problems such as software delay, resource consumption, and complex hardware design in high-speed dynamic control such as magnetic levitation, providing a full-link hardware optimization architecture for high-precision current control while maintaining reliability and engineering practicality.

[0051] Finally, it should be noted that the above description is only a preferred embodiment of this application and is not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A current closed-loop control circuit, characterized in that, include: The module includes a current sensing module, a signal conditioning module, an error amplification module, a PI control module, a PWM modulation module, and a power drive module. The measurement output terminal of the current sensing module is connected to the input terminal of the signal conditioning module. The output terminal of the signal conditioning module is connected to the input terminal of the error amplification module. The output terminal of the error amplification module is connected to the input terminal of the PI control module. The output terminal of the PI control module is connected to the input terminal of the PWM modulation module. The output terminal of the PWM modulation module is connected to the input terminal of the power drive module. The output terminal of the power drive module is connected to the input terminal of the current sensing module.

2. The current closed-loop control circuit according to claim 1, characterized in that, The current sensing module includes a current sensor U36, a capacitor C157, a capacitor C159, and a power connector O9. Pins 1, 2, and 3 of the current sensor U36 are all connected to the output terminal of the power drive module; pins 4, 5, and 6 of the current sensor U36 are all connected to the positive terminal of the power connector O9, and the negative terminal of the power connector O9 is connected to the output terminal of the power drive module; pin 7 of the current sensor U36 and one end of the capacitor C159 are both connected to -12V, and the other end of the capacitor C159 is grounded; pin 8 of the current sensor U36 and one end of the capacitor C157 are both connected to +12V, and the other end of the capacitor C157 is grounded; pin 9 of the current sensor U36 is the measurement output terminal, which outputs signal U36-M to the input terminal of the signal conditioning module.

3. The current closed-loop control circuit according to claim 2, characterized in that, The signal conditioning module includes capacitor C158, resistor R306 and resistor R304; One end of capacitor C158 and one end of resistor R306 are both connected to the measurement output terminal of the current sensing module to receive the signal U36-M; one end of capacitor C158 and one end of resistor R306 are also connected to the input terminal of the error amplification module; the other end of capacitor C158, the other end of resistor R306 and one end of resistor R304 are all grounded, and the other end of resistor R304 is connected to the input terminal of the error amplification module.

4. The current closed-loop control circuit according to claim 3, characterized in that, The error amplification module includes operational amplifier U34C, resistor R305, resistor R291, resistor R292, operational amplifier U34D, resistor R285, and resistor R282; The non-inverting input terminal of operational amplifier U34C is connected to one end of capacitor C158 and one end of resistor R306. The non-inverting input terminal of operational amplifier U34C is connected to the other end of resistor R304 and one end of resistor R305. The output terminal of operational amplifier U34C and the other end of resistor R305 are both connected to one end of resistor R285. One end of resistor R291 receives the reference current signal U4-1OUT. The other ends of resistor R291 and one end of resistor R292 are both connected to the non-inverting input terminal of operational amplifier U34D. The other end of resistor R292 is grounded. The other end of resistor R285 and one end of resistor R282 are both connected to the non-inverting input terminal of operational amplifier U34D. The other end of resistor R282 and the output terminal of operational amplifier U34D are both connected to the input terminal of the PI control module.

5. The current closed-loop control circuit according to claim 4, characterized in that, The PI control module includes resistor R293, resistor R286, operational amplifier U34B, resistor R281, capacitor C145, resistor R294, resistor R289, inverter U34A, capacitor C147, capacitor C146 and resistor R283. One end of resistor R293 is grounded, and the other end of resistor R293 is connected to the non-inverting input terminal of operational amplifier U34B. One end of resistor R286 is connected to the other end of resistor R282 and the output terminal of operational amplifier U34D. The other end of resistor R286, one end of resistor R281, and one end of capacitor C145 are all connected to the non-inverting input terminal of operational amplifier U34B. One end of resistor R289, the other end of resistor R281, and the other end of capacitor C145 are all connected to the output terminal of operational amplifier U34B. The other end of resistor R289 and resistor R283... One end of each resistor is connected to the negative input terminal of the inverter U34A, and the other end of the resistor R283 is connected to the input terminal of the PWM modulation module; one end of the resistor R294 is grounded, and the other end of the resistor R294 is connected to the positive input terminal of the inverter U34A; the positive power supply pin of the inverter U34A and one end of the capacitor C147 are both connected to +12V, and the other end of the capacitor C147 is grounded; the negative power supply pin of the inverter U34A and one end of the capacitor C146 are both connected to -12V, and the other end of the capacitor C146 is grounded; the output terminal of the inverter U34A is connected to the input terminal of the PWM modulation module.

6. The current closed-loop control circuit according to claim 5, characterized in that, The PWM modulation module includes resistors R278, R287, R280, and R290, comparator U30C, operational amplifier U30D, resistors R277, R284, R279, and R288, diodes D54 and D55, resistor R295, capacitor C148, and capacitor C152. One end of resistor R278 is connected to the output of inverter U34A, and the other end of resistor R278 is connected to the non-inverting input of comparator U30C. One end of resistors R280 and R290 both receive signal U3-1OUT. The other end of resistor R280 is connected to the inverting input of comparator U30C, and the other end of resistor R290 is connected to the inverting input of operational amplifier U30D. One end of resistor R287 is connected to the other end of resistor R283, and the other end of resistor R287 is connected to the non-inverting input of operational amplifier U30D. One end of resistors R277 and R279 are both connected to the output of comparator U30C, and the other end of resistor R277 is connected to +12V. The other end of resistor R279 and the cathode of diode D54 are both connected to one end of resistor R295. The anode of diode D54 is grounded. The other end of resistor R295 is connected to one end of capacitor C148 to output signal U35-INA. The other end of capacitor C148 is grounded. One end of resistor R284 and one end of resistor R288 are both connected to the output terminal of operational amplifier U30D. The other end of resistor R284 is connected to +12V. The other end of resistor R288 and the cathode of diode D55 are both connected to one end of resistor R299. The anode of diode D55 is grounded. The other end of resistor R299 is connected to one end of capacitor C152 to output signal U35-INB. The other end of capacitor C152 is grounded.

7. The current closed-loop control circuit according to claim 6, characterized in that, The power drive module includes a gate driver U35, MOSFETs Q17 and Q18, capacitors C154 and C153, diodes D56 and C149, resistors R303 and C155, resistors R297 and D59, resistors R301, R300, R302, R298, diodes D58 and D57, and a polarized capacitor C21. Pins 3 and 8 of the gate driver U35 and one end of capacitor C154 are all connected to +12V, and the other end of capacitor C154 is grounded. Pin 1 of the gate driver U35 receives the signal U35-INA, and pin 2 of the gate driver U35 receives the signal U35-INB. Pin 6 of the gate driver U35 and one end of capacitor C153 are both connected to +12V, and the other end of capacitor C153 and pin 4 of the gate driver U35 are grounded. Pin 16 of the gate driver U35 and one end of capacitor C149... All terminals are connected to the cathode of diode D56, and the anode of diode D56 is connected to VO+. The other end of capacitor C149 and pin 14 of gate driver U35 are both connected to one end of resistor R303, and the other end of resistor R303 is connected to V-. The other end of capacitor C149, pin 14 of gate driver U35, one end of resistor R303, and the cathode of diode D59 are all connected to one end of resistor R300, and the anode of diode D59 is connected to V-. The other end of resistor R300, the cathode of diode D56, and the cathode of gate driver U35 are all connected to one end of resistor R300. One end of resistor R298, the cathode of diode D58, and the source of MOSFET Q17 are connected to pins 1, 2, and 3 of current sensor U36. Pin 15 of gate driver U35 is connected to one end of resistor R297. The other ends of R297 and R298 are both connected to the gate of MOSFET Q17. The drain of MOSFET Q17 and the positive terminal of polarized capacitor C21 are both connected to HV, and the negative terminal of polarized capacitor C21 is connected to V-. Pin 11 of gate driver U35 and capacitor C... One end of capacitor C155 is connected to VO+. Pin 9 of gate driver U35, the other end of capacitor C155, and one end of resistor R302 are all connected to the source of MOSFET Q18. Pin 10 of gate driver U35 is connected to one end of resistor R301. The other ends of resistor R301 and resistor R302 are both connected to the gate of MOSFET Q18. The negative terminal of power connector O9 and the drain of MOSFET Q18 are both connected to the positive terminal of diode D57. The negative terminal of diode D57 is connected to HV.

Images