Pulse charge-discharge control system and method based on online identification of load parameters

Abstract

Embodiments of the present application disclose a pulse charging and discharging control system and method based on online identification of load parameters. The system comprises, in sequence, a power supply, an interleaved parallel synchronous Buck energy storage circuit, a charging and discharging circuit, a load, a sampling circuit and a control circuit. The control circuit is configured to perform online identification of equivalent resistance and energy storage inductance parameters of the load according to a sampling voltage, a sampling current and a switching device driving edge signal, and to substitute the identified equivalent resistance and equivalent inductance into a current loop PI parameter and an initial duty cycle calculation formula to adaptively correct a PWM driving signal of a pulse charging and discharging process. The embodiments of the present application can reduce the influence of load parameter changes on a pulse current waveform and improve the control stability and adaptability of a multi-phase interleaved parallel pulse current source under different load conditions.

Description

Technical Field

[0001] This application relates to the field of power electronics and pulse current source control, and in particular to a pulse charge and discharge control system and method based on online identification of load parameters. Background Technology

[0002] With the development of high-power semiconductor lasers, pulsed load testing devices, and energy storage pulsed power supplies, higher requirements are placed on the rise rate, steady-state ripple, overshoot, and repetition consistency of the load pulse current. Interleaved parallel synchronous Buck structures can reduce output current ripple and improve power rating and heat dissipation through multiphase current superposition.

[0003] However, in practical applications, energy storage inductors and circuits have parasitic resistance, and the equivalent load parameters may also shift due to changes in device temperature rise, connection impedance, operating current, and external load. When the controller still uses fixed resistance and inductance parameters to calculate the PI coefficient and initial duty cycle, problems such as current rise slope deviation, steady-state current deviation, increased overshoot, and decreased control performance after parameter changes are likely to occur.

[0004] Therefore, it is necessary to provide a pulse charge-discharge control system and method that can identify the equivalent resistance and equivalent inductance in real time during pulse charge-discharge and adaptively update the control parameters based on the identification results. Summary of the Invention

[0005] This application provides a pulse charge-discharge control system and method based on online identification of load parameters, which solves the technical problem that the controller in the prior art is prone to a decrease in control effect.

[0006] To achieve the above objectives, this application adopts the following technical solution: In a first aspect, a pulse charge-discharge control system based on online identification of load parameters is provided. The system includes a power supply, an interleaved parallel synchronous Buck energy storage circuit, a charge-discharge circuit, a load, a sampling circuit, and a control circuit. The interleaved parallel synchronous Buck energy storage circuit includes multiple synchronous Buck branches, and each synchronous Buck branch includes an upper switching device, a lower switching device, and an energy storage inductor. The sampling circuit is used to collect the voltage signal, current signal, and drive edge signal of the switching device in the charging and discharging circuit of the energy storage inductor or load branch. The charging and discharging circuit includes switching devices. and , The IGBT switching device in the discharge branch is used to control the on and off of the discharge circuit of the energy storage inductive load.

[0007] The control circuit includes a load parameter identification module and a control parameter update module. The load parameter identification module is configured to identify the equivalent resistance online based on the voltage signal, current signal, and drive edge signal. and equivalent inductance The control parameter update module is configured to update the equivalent resistance. and equivalent inductance Substitute the current loop control parameters and the initial duty cycle into the calculation formula to generate the pulse width modulation signal used to drive the synchronous Buck branch.

[0008] Based on the above technical solution, in the pulse charge and discharge control system based on online load parameter identification provided in this application, voltage signals, current signals, and switching device drive edge signals are collected by a sampling circuit. The equivalent resistance and equivalent inductance are identified online by the load parameter identification module. Then, the control parameter update module substitutes the identified parameters into the current loop control parameters and the initial duty cycle calculation formula, thereby realizing the online adaptive adjustment of control parameters to load changes, and thus maintaining a stable pulse current output under different load conditions.

[0009] In conjunction with the first aspect above, in one possible implementation, the load parameter identification module is configured to average the sampled voltage and sampled current within a preset sampling window, and based on the average voltage... Average current and device on-state voltage drop Calculate the equivalent resistance .

[0010] By performing averaging within a preset sampling window, the influence of PWM switching ripple and sampling noise on voltage and current signals can be effectively filtered out, making the identification results of equivalent resistance more accurate and stable.

[0011] In conjunction with the first aspect above, in one possible implementation, the equivalent resistance According to the calculation formula Calculated.

[0012] In conjunction with the first aspect above, in one possible implementation, the load parameter identification module is configured to use the charging and discharging circuit... The turn-off edge of the switching device is used as the sampling start point for the falling edge of the current to obtain the starting current of the falling edge. End current Start time and end time The equivalent inductance is calculated based on the current drop slope. .

[0013] By using the driving edge signal of the switching device as the trigger signal for falling edge sampling, the start time of the current falling edge can be accurately located, avoiding sampling errors caused by control delay or timing offset, thereby improving the accuracy and reliability of inductor identification.

[0014] In conjunction with the first aspect above, in one possible implementation, the equivalent inductance According to the calculation formula Calculated; In the formula, , .

[0015] In conjunction with the first aspect above, in one possible implementation, the control parameter update module updates the equivalent resistance. Write The equivalent inductance Write And based on the control bandwidth BW and bus voltage and equivalent total resistance Update current loop proportional coefficient With integral coefficient Wherein, the control bandwidth BW is the bandwidth preset according to the controller response speed; where, the control bandwidth BW is the design parameter preset according to the controller's expected response speed.

[0016] In conjunction with the first aspect above, in one possible implementation, the equivalent total resistance... R tot The equivalent resistance With additional series resistor The sum of; when the equivalent resistance When the parasitic resistance of the energy storage inductor and the equivalent resistance of the line are already included, the additional series resistance Take zero.

[0017] By setting an additional series resistance term, the system can flexibly adapt to different resistance modeling methods, avoiding the duplication of resistance term calculations.

[0018] In conjunction with the first aspect described above, in one possible implementation, the control parameter update module further updates the current... Target current Charging time Device on-state voltage drop and the equivalent total resistance Calculate the initial duty cycle Compared with the initial duty cycle of charging .

[0019] By calculating the initial duty cycle, the system can start with a near-steady-state duty cycle at the pulse initiation stage, thereby improving the rise response speed of the pulse current and the control accuracy in the initial stage.

[0020] In conjunction with the first aspect above, in one possible implementation, the interleaved parallel synchronous Buck energy storage circuit includes three-phase synchronous Buck branches, each of which outputs approximately 50A of pulse current, and the three-phase combined outputs approximately 150A of pulse current.

[0021] Secondly, a pulse charge-discharge control method based on online load parameter identification is provided, the method comprising: acquiring voltage signals, current signals, and... Drive edge signal; The voltage and current signals are averaged and the equivalent resistance is identified within a preset window. according to Identify the equivalent inductance by the slope of the current falling edge after turn-off; Substitute the identified equivalent resistance and equivalent inductance into the current loop PI parameters and the initial duty cycle calculation formula; A PWM drive signal is generated based on the updated control parameters to ensure stable output of the load pulse current.

[0022] This application provides a pulse charge-discharge control system and method based on online load parameter identification. By jointly sampling voltage, current, and drive edge signals, the equivalent resistance and equivalent inductance of the load are identified online. By feeding the identified parameters back to the current loop controller, the proportional parameters, integral parameters, and initial duty cycle are adaptively updated, thereby maintaining a stable pulse current output when the load parameters change. This improves the adaptability of the pulse charge-discharge system to load parameter changes. Furthermore, it can identify the equivalent resistance and equivalent inductance online and adaptively update the current loop control parameters and initial duty cycle based on the identification results, thereby improving the stability of the pulse current output.

[0023] It should be understood that the descriptions of technical features, technical solutions, beneficial effects, or similar language in this application do not imply that all features and advantages can be achieved in any single embodiment. Rather, it is understood that the description of a feature or beneficial effect means that a specific technical feature, technical solution, or beneficial effect is included in at least one embodiment. Therefore, the descriptions of technical features, technical solutions, or beneficial effects in this specification do not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions, and beneficial effects described in this embodiment can be combined in any suitable manner. Those skilled in the art will understand that embodiments can be implemented without one or more specific technical features, technical solutions, or beneficial effects of a particular embodiment. In other embodiments, additional technical features and beneficial effects may be identified in specific embodiments that do not embody all embodiments. Attached Figure Description

[0024] Figure 1 A flowchart illustrating an embodiment of the online load parameter identification and control parameter update method provided in this application is shown. Figure 2 A schematic flowchart of a pulse charge-discharge control method according to an embodiment of this application is shown; Figure 3 A timing diagram of the charging / discharging timing control signal and the Buck drive signal provided in one embodiment of this application is shown. Figure 4 This illustration shows a schematic diagram of the current falling edge inductance identification principle provided in one embodiment of this application; Figure 5 This illustration shows a schematic diagram of the resistance identification and inductance identification results provided in one embodiment of this application; Figure 6 This illustration shows a schematic diagram of the resistance identification and inductance identification results provided in another embodiment of this application; Figure 7 This illustration shows a schematic diagram of the percentage of resistance and inductance identification errors provided in one embodiment of this application; Figure 8 This paper illustrates a schematic diagram of the drive signal and current waveforms when a single-phase 50A output is provided according to an embodiment of this application. Figure 9 This paper illustrates a schematic diagram of a three-phase parallel 150A output current waveform according to an embodiment of this application. Figure 10 A schematic diagram of a structure for correcting controller parameters based on identification parameters is shown in one embodiment of this application. Detailed Implementation

[0025] In the description of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. The "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Furthermore, "at least one" means one or more, and "multiple" means two or more. The terms "first," "second," etc., do not limit the quantity or order of execution, and "first," "second," etc., do not necessarily imply differences.

[0026] It should be noted that, in this application, the terms "exemplary" or "for example" are used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0027] Please refer to Figure 1 The diagram illustrates a flowchart of an embodiment of the online identification of load parameters and update of control parameters provided in this application.

[0028] The online load parameter identification and control parameter update method is used to identify the equivalent resistance and equivalent inductance of the load branch online during the operation of the pulse charge-discharge system, and to correct the current loop controller parameters and initial duty cycle based on the identified parameters.

[0029] Specifically, the method includes: acquiring load branch voltage signals, current signals, and switching device drive signals; calculating the equivalent resistance based on the voltage and current signals; determining the current falling edge sampling interval based on the switching device drive signals, and calculating the equivalent inductance in conjunction with the identified equivalent resistance; feeding back the identified equivalent resistance and equivalent inductance to the main control unit; updating the proportional parameters, integral parameters, and initial duty cycle based on the identification results; and finally outputting the corrected PWM drive signal to ensure stable output of the load current under different load parameters.

[0030] In this embodiment, Figure 1 The process shown can be executed by the main control unit, or by the main control unit and an independent load parameter identification unit. The load parameter identification unit can be implemented using a DSP, MCU, FPGA, or other controllers with data processing capabilities. Figure 1The load parameter identification process is not an isolated detection process, but is combined with the current closed-loop control process. That is to say, the identified equivalent resistance and equivalent inductance are not only used for display or monitoring, but also further participate in the controller parameter update and duty cycle correction, thus forming a closed-loop adaptive control process of "parameter identification - control parameter update - current output correction".

[0031] Please refer to Figure 2 This document illustrates a schematic diagram of a pulse charge-discharge control system according to an embodiment of this application. The pulse charge-discharge control system includes a DC power supply, multiple interleaved parallel synchronous Buck modules, a charge-discharge circuit, a load, a main control unit, an interleaved parallel synchronous control circuit, a charge-discharge timing control circuit, a voltage sampling circuit, a current sampling circuit, and an online load parameter identification module. The multiple interleaved parallel synchronous Buck modules collectively constitute an energy storage circuit. Each synchronous Buck module includes an upper-side switching device, a lower-side switching device, an energy storage inductor, and an equivalent parasitic resistance connected in series with the energy storage inductor. The equivalent parasitic resistance may include the energy storage inductor winding resistance, the connecting conductor resistance, the device conduction equivalent resistance, and other equivalent series resistances located in the current loop.

[0032] Specifically, Figure 2 The left side shows a multi-phase interleaved parallel synchronous Buck circuit model, and the right side shows an IGBT charging and discharging model. In the charging and discharging circuit: Charging phase: During this phase, Conductive, When switched off, the load LD is isolated from the energy storage circuit, and there is temporarily no load current. The switching transistors in each parallel Buck module... , ...operating according to the PWM control law, causing the DC bus to operate within the energy storage inductor ( , A positive voltage is established across the terminals. The inductor current in each branch gradually increases and stores energy through parallel current sharing. During this stage, and It mainly serves as a freewheeling current generator and a voltage clamping device.

[0033] Discharge phase (pulse formation phase): In this phase, Shut down When the circuit is turned on, the common output terminal of the energy storage circuit is connected to the load LD. The energy is stored in (…). , The energy in ....,) As the load is released, the output currents of each Buck module converge at the common node, forming the required load pulse current. During the discharge process, the switching transistors of each group... , ...continue to use high-frequency PWM control to adjust the amplitude of the load current. When When shut down, and Provides a freewheeling or energy feedback path for residual current.

[0034] exist Figure 2 In the system shown, a DC power supply provides input energy to multiple synchronous Buck modules. The interleaved parallel synchronous control circuit generates PWM drive signals with preset phase differences for each synchronous Buck module based on control commands output from the main control unit. Because the synchronous Buck modules operate interleaved, the inductor current ripple of each phase can cancel each other out at the total output, thereby reducing the output current ripple on the load side. The charge / discharge timing control circuit controls the switching devices in the charge / discharge circuit, enabling the system to switch between the energy storage phase, the discharge phase, and the energy feedback phase.

[0035] The charging and discharging circuit includes switching devices. and , The IGBT switching device in the discharge branch is used to control the on and off of the discharge circuit of the energy storage inductive load.

[0036] Furthermore, the voltage sampling circuit is used to acquire the voltage signal of the load branch or the equivalent resistance branch, and the current sampling circuit is used to acquire the load current or inductor current signal. The online load parameter identification module receives the voltage signal, current signal, and switch drive signal, and calculates the equivalent resistance according to a preset identification algorithm. and equivalent inductance The aforementioned and The results are transmitted to the main control unit, which updates the parameters of the controlled object based on the identification results. and Furthermore, the current loop controller parameters and the initial duty cycle were further modified.

[0037] Please refer to Figure 3 It shows a timing diagram of the charging and discharging timing control signal and the synchronous Buck drive signal provided in one embodiment of this application. Figure 3 The middle section, from top to bottom, can include the following: , , and .in, and It can be used to control the operating state of the charging and discharging circuit. and It can be used to control the conduction state of the upper and lower transistors in a synchronous Buck module. By controlling... , , and With precise timing control, the system can sequentially perform energy storage, discharge, and energy feedback processes.

[0038] During the energy storage phase, the corresponding switching devices in the charging and discharging circuit are in a state where the load branch does not output current. The interleaved parallel synchronous control circuit outputs PWM drive signals to each synchronous Buck module, enabling the DC power supply to charge each phase energy storage inductor through the synchronous Buck module. At this time, the inductor current of each phase rises according to the set slope, and energy gradually accumulates in the energy storage inductor.

[0039] During the discharge phase, the charge / discharge timing control circuit controls the corresponding switching devices to turn on, allowing the current in the energy storage inductor to be released through the load branch. At this time, the inductor currents of multiple synchronous Buck modules are superimposed to form the total load current. For a three-phase interleaved parallel system, when the current per phase is approximately 50A, the total output current on the load side can reach approximately 150A. Through current closed-loop control and adaptive updating of load parameters, the system can maintain a relatively stable output current during the discharge phase.

[0040] During the energy feedback phase, the charging and discharging timing control circuit shuts off the discharge branch, allowing the remaining energy in the energy storage inductor to return to the DC power supply side through the feedback path. This phase reduces energy loss and minimizes the impact of residual inductor current on the next pulse cycle.

[0041] Furthermore, Figure 3 In The drive signal is used not only to control the state of the discharge circuit, but also for timing positioning during the load parameter identification process. Specifically, during inductor identification, the main control unit can, according to... The turn-off edge determines the start time of the current falling edge. Compared to calculating the starting point of the falling edge based solely on a fixed period, triggering using the actual drive signal edge avoids sampling errors caused by switching delays, control delays, or timing offsets.

[0042] Please refer to Figure 4 This illustrates a schematic diagram of the current falling edge inductance identification principle provided in one embodiment of this application. Figure 4 In the middle, the current flows from Descending to The corresponding time is from Change to The main control unit detects... After the turn-off edge, record the starting current at the falling edge. and start time And record the final current when the current drops to near zero or when the dropping process ends. and end time Therefore, the slope of the current falling edge can be obtained: ; Meanwhile, the average current within the current falling edge interval can be expressed as: ; During the freewheeling decline phase, the energy storage inductor releases energy, and the inductor voltage is mainly used to overcome the equivalent resistance voltage drop of the load circuit and the on-state voltage drop of the device. Therefore, the equivalent inductance... It can be represented as: ; It can be further written as: ; in, The equivalent resistance of the identified load circuit is... This represents the equivalent forward voltage drop of the switching device or diode in the freewheeling path. As shown in the formula above, inductor identification depends on the current falling edge slope; therefore, it is necessary to accurately determine the falling edge sampling interval. If the starting point of the falling edge is offset, or if current outside the falling edge is sampled, it will lead to… Inaccurate calculations can affect the inductance identification results. Therefore, this embodiment uses a drive signal edge triggering method to determine the falling edge start point, thereby improving the reliability of inductance identification.

[0043] In this embodiment, the load parameter identification module is configured to average the sampled voltage and sampled current within a preset sampling window. Specifically, within a preset time window, the sampled voltage and sampled current are averaged respectively to obtain an average voltage. and average current Because synchronous Buck circuits exhibit PWM ripple, current ripple, and switching transient spikes during operation, directly using instantaneous voltage and current to calculate resistance can easily lead to significant fluctuations in the identification results. Therefore, window averaging effectively reduces the impact of high-frequency ripple and sampling noise on the identification results. The equivalent resistance can be calculated using the following formula: ; in, This represents the on-state voltage drop of the device. It should be noted that within a long averaging window and when the average current changes slowly, the average inductor voltage within that window is close to zero. Therefore, the average voltage primarily reflects the equivalent resistance voltage drop. If the average current is still in a significant rising or falling phase, an inductor voltage compensation term can be further introduced to improve the resistance identification accuracy.

[0044] In this embodiment, the control parameter update module updates the equivalent resistance. Equivalent inductance Control bandwidth BW, bus voltage and equivalent total resistance Update current loop proportional coefficient With integral coefficient .

[0045] Among them, the control bandwidth BW is a design parameter preset according to the expected response speed of the controller, and its value is determined by those skilled in the art based on the dynamic response indicators of the system (such as rise time, settling time, etc.).

[0046] Specifically, the current loop controlled object can be approximated as: ; in, This is the DC bus voltage. The equivalent inductance of the load circuit, Let be the total equivalent resistance of the load loop. Based on the set current loop bandwidth BW, the controller's proportional and integral parameters can be expressed as follows: ; ; Optionally, the equivalent total resistance The equivalent resistance With additional series resistor The sum of; when the equivalent resistance When the parasitic resistance of the energy storage inductor and the equivalent resistance of the line are already included, the additional series resistance Set to zero. By setting an additional series resistance term, the system can flexibly adapt to different resistance modeling methods, avoiding redundant calculations of the resistance term.

[0047] Furthermore, to improve the response consistency during the pulse initiation phase, the main control unit can calculate the initial duty cycle based on the identified equivalent resistance and equivalent inductance. The steady-state initial duty cycle can be expressed as: ; The initial duty cycle of charging can be expressed as: ; in, For the target current, For the current, Preset charging time, This represents the equivalent on-state voltage drop of the device. The initial duty cycle calculation described above considers the inductor charging voltage, resistor voltage drop, and device on-state voltage drop simultaneously. Compared to the method of calculating the initial duty cycle based solely on the change in inductor current, this improves the initial control accuracy under different load parameters.

[0048] Please refer to Figure 5 and Figure 6 The diagram illustrates the resistance and inductance identification results provided in one embodiment of this application. Figure 5 and Figure 6 This can include equivalent resistance identification curves. and equivalent inductance identification curve For example, Figure 5 Under the first load parameter condition, with the equivalent load resistance set to 0.02Ω and the equivalent load inductance set to 3.3μH, the online load parameter identification module can... It converges to approximately 0.02 Ω, and makes It converges to approximately 3.3 μH. Figure 6 Under the second load parameter condition, with the equivalent load resistance set to 0.04Ω and the equivalent load inductance set to 6μH, the online load parameter identification module can... It converges to approximately 0.04 Ω, and makes The convergence rate was approximately 6 μH. These results verify that the online load parameter identification method provided in this application exhibits good convergence performance under different load conditions.

[0049] Please refer to Figure 7 This illustrates a schematic diagram of the percentage of resistance and inductance identification errors provided in one embodiment of this application. Figure 6 The identification error was calculated under load parameters (R=0.04Ω, L=6μH). The percentage of error can be calculated using the following formula: Error = |Identification value - Set value| / Set value × 100%; When R = 0.04Ω and L = 6μH are set, the maximum error identification result is: , ,but: The resistor identification error is approximately: |0.0398-0.04| / 0.04×100%≈0.5% The inductor identification error is approximately: |6.0035-6| / 6×100%≈0.006% Depend on Figure 7 It can be seen that the online load parameter identification method can maintain a small identification error when the load parameters change. The reason for the small resistance identification error is that the resistance identification uses a window averaging method, which can effectively filter out PWM ripple and sampling noise. The inductor identification error mainly comes from the error in determining the start and end points of the current falling edge, sampling delay, current ripple, and the approximate error of the device's on-state voltage drop. By adopting a drive signal edge triggering and falling edge sampling method, the falling edge positioning error can be reduced, thereby improving the inductor identification accuracy.

[0050] Please refer to Figure 8 It shows a schematic diagram of the drive signal and current waveform when a single-phase 50A output is provided in an embodiment of this application. Figure 8 It can include , , , And single-phase inductor current or load current. Through Figure 7 It can be seen that when the single-phase synchronous Buck module is working, and Used to determine the charging and discharging phases and Used to adjust the inductor current of the synchronous Buck module. When the target current is 50A, after adding online load parameter identification and control parameter updates, the single-phase output current can remain stable during the discharge phase, and current overshoot and steady-state error are suppressed.

[0051] In this single-phase verification process, the online load parameter identification module first estimates the equivalent resistance based on the sampled voltage and sampled current. ; then according to Estimating the equivalent inductance based on the falling edge of the current after turn-off The main control unit further... and The proportional and integral parameters of the current loop, as well as the initial duty cycle, are corrected. Therefore, the effectiveness of the identification method and control parameter update method can be verified under single-phase 50A operating conditions.

[0052] Please refer to Figure 9 The diagram illustrates a schematic of a three-phase interleaved parallel 150A output current waveform according to an embodiment of this application. In the three-phase interleaved parallel system, the inductor current of each phase is approximately 50A, which, after being superimposed in parallel, forms a total load current of approximately 150A. Due to the preset phase difference between the PWM drive signals of each phase, the current ripple of each phase partially cancels out at the total output terminal, making the total output current ripple smaller than the case where the ripple of a single phase is directly superimposed.

[0053] In the verification of a three-phase parallel 150A output, the online load parameter identification module can collect the total load current or the single-phase inductor current, and estimate the total equivalent load parameters or single-phase equivalent parameters according to the actual control requirements. For the total current control mode, the main control unit can calculate the equivalent load parameters based on the total output current and the load terminal voltage; for the phase-by-phase control mode, the main control unit can estimate the inductor parameters of each phase separately and correct the PWM duty cycle of each phase. Figure 8 The method employs total current control, and even when the multi-phase parallel expansion reaches 150A output, it can still maintain a stable pulse current output.

[0054] Please refer to Figure 10 This illustrates a schematic diagram of a structure for correcting controller parameters based on identification parameters, provided in one embodiment of this application. Figure 10 In the middle, the online load parameter identification module outputs... and The main control unit according to the and Update control object parameters And L, and further calculate the current loop controller parameters. , Steady-state initial duty cycle and initial duty cycle of charging .

[0055] Specifically, the main control unit can, based on the identified... and Calculate according to the above formula , , and The updated parameters are then applied to the current loop control.

[0056] Furthermore, to avoid the impact of sudden changes in identification parameters on the control process, the main control unit can... , , , , as well as Perform amplitude limiting and smoothing processing. For example, when the identified... or When the value exceeds the preset reasonable range, the main control unit can maintain the previous valid identification value; when the identification result changes within the reasonable range, the main control unit can gradually update the control parameters using a weighted smoothing method to avoid sudden changes in the controller parameters that cause the PWM duty cycle to jump.

[0057] This embodiment also provides a pulse charge-discharge control system based on online identification of load parameters. The system includes a power supply, an interleaved parallel synchronous Buck energy storage circuit, a charge-discharge circuit, a load, a sampling circuit, and a control circuit. The interleaved parallel synchronous Buck energy storage circuit includes multiple synchronous Buck branches, and each synchronous Buck branch includes an upper switching device, a lower switching device, and an energy storage inductor. The sampling circuit is used to collect the voltage signal, current signal, and drive edge signal of the switching device in the charging and discharging circuit of the energy storage inductor or load branch. The control circuit includes a load parameter identification module and a control parameter update module. The load parameter identification module is configured to identify the equivalent resistance online based on the voltage signal, current signal, and drive edge signal. and equivalent inductance The control parameter update module is configured to update the equivalent resistance. and equivalent inductance Substitute the current loop control parameters and the initial duty cycle into the calculation formula to generate the pulse width modulation signal used to drive the synchronous Buck branch.

[0058] In summary, this embodiment achieves online identification of the equivalent resistance and equivalent inductance of the load through joint sampling of voltage, current, and drive signals; by feeding back the identified parameters to the current loop controller, it achieves adaptive updates of proportional parameters, integral parameters, and initial duty cycle; and through verification using single-phase 50A and three-phase parallel 150A outputs, it demonstrates that the method can maintain a stable pulse current output when load parameters change, thereby improving the adaptability of the pulse charge-discharge system to changes in load parameters.

[0059] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, disclosure, and appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0060] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if such modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and modifications.

Claims

1. A pulse charge-discharge control system based on online load parameter identification, characterized in that, The system includes a power supply, an interleaved parallel synchronous Buck energy storage circuit, a charging and discharging circuit, a load, a sampling circuit, and a control circuit; the interleaved parallel synchronous Buck energy storage circuit includes multiple synchronous Buck branches, and each synchronous Buck branch includes an upper switching device, a lower switching device, and an energy storage inductor; The sampling circuit is used to collect the voltage signal, current signal, and drive edge signal of the switching device in the charging and discharging circuit of the energy storage inductor or load branch. The control circuit includes a load parameter identification module and a control parameter update module. The load parameter identification module is configured to identify the equivalent resistance online based on the voltage signal, current signal, and drive edge signal. and equivalent inductance The control parameter update module is configured to update the equivalent resistance. and equivalent inductance Substitute the current loop control parameters and the initial duty cycle into the calculation formula to generate a pulse width modulation signal for driving the synchronous Buck branch.

2. The system according to claim 1, characterized in that, The load parameter identification module is configured to average the sampled voltage and sampled current within a preset sampling window, and then calculate the average voltage based on the average voltage. Average current and device on-state voltage drop Calculate the equivalent resistance .

3. The system according to claim 2, characterized in that, The equivalent resistance According to the calculation formula Calculated.

4. The system according to claim 2, characterized in that, The load parameter identification module is configured to use a discharge switching device in the charging and discharging circuit. The turn-off edge is used as the sampling start point for the falling edge of the current to obtain the starting current of the falling edge. End current Start time and end time The equivalent inductance is calculated based on the current drop slope. .

5. The system according to claim 4, characterized in that, The equivalent inductance According to the calculation formula Calculated; In the formula, , .

6. The system according to claim 1, characterized in that, The control parameter update module updates the equivalent resistance based on the equivalent resistance. The equivalent inductance Control bandwidth BW, bus voltage and equivalent total resistance Update the current loop proportional coefficient With integral coefficient .

7. The system according to claim 6, characterized in that, The equivalent total resistance R tot The equivalent resistance With additional series resistor The sum of; when the equivalent resistance When the parasitic resistance of the energy storage inductor and the equivalent resistance of the line are already included, the additional series resistance Take zero.

8. The system according to claim 6, characterized in that, The control parameter update module also updates the current. Target current Charging time Device on-state voltage drop and the equivalent total resistance Calculate the initial duty cycle Compared with the initial duty cycle of charging .

9. The system according to claim 1, characterized in that, The interleaved parallel synchronous Buck energy storage circuit includes three-phase synchronous Buck branches, each of which outputs approximately 50A of pulse current, and the three phases combined output approximately 150A of pulse current.

10. A pulse charge-discharge control method based on online load parameter identification, applied to the system described in any one of claims 1-9, characterized in that, The method includes: acquiring voltage signals, current signals, and signals from the pulse charging and discharging circuit. Drive edge signal; The voltage and current signals are averaged and the equivalent resistance is identified within a preset window. according to Identify the equivalent inductance by the slope of the current falling edge after turn-off; Substitute the identified equivalent resistance and equivalent inductance into the current loop PI parameters and the initial duty cycle calculation formula; A PWM drive signal is generated based on the updated control parameters to ensure stable output of the load pulse current.

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