Design method of uncertain IGBT electronic load controller

Abstract

The invention discloses a design method of an uncertain IGBT electronic load controller, which relates to the technical field of electronic loads, and comprises the following steps: establishing a small signal model of an IGBT constant-current driving circuit, and decomposing the small signal model into an operational amplifier, a driving stage and an IGBT module to obtain an open-loop transfer function without compensation; combining a controller model and an uncompensated open-loop transfer function, analyzing structured and unstructured uncertainty, calculating a multiplicative uncertainty upper bound and determining a weighting function; and inputting the controller model, the uncompensated open-loop transfer function and the weighting function into a robust Bode diagram, verifying whether an open-loop frequency curve avoids a forbidden zone, adjusting a backstepping controller parameter through iteration, and outputting a qualified controller. According to the method, parameter fluctuation is modeled as structured uncertainty, actually measured gain offset is modeled as unstructured, and a robust stability weighting function is defined through multiplicative uncertainty boundary fusion, so that the gain margin of the controller to the gate and emitter parasitic capacitance change of the IGBT is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic loads, in particular to a design method for an IGBT electronic load controller with uncertainties. Background Art

[0002] The technology of electronic loads has evolved from traditional resistive loads to energy-feedback electronic loads. In the early days, resistive loads were limited by power density and dynamic response speed, and were gradually replaced by active electronic loads based on power semiconductor devices. Energy-feedback electronic loads achieve energy feedback through a rectification-inversion topology, but their complex control structure and sensitivity to grid parameters limit the application scenarios. In recent years, IGBT energy-consuming electronic loads have become the mainstream solution due to their excellent thermal control performance and strong single-tube power handling ability. Its core control strategy realizes constant current control by adjusting the conduction amount of the IGBT through a drive circuit, and forms a closed-loop system by combining error amplification, drive-stage power amplification, and sampling feedback. With the development of third-generation semiconductor devices, the influence of IGBT parasitic parameters on system stability has become increasingly prominent, and the small-signal modeling of the drive circuit and the design of the compensation network have become the research focus.

[0003] The design of traditional IGBT electronic load controllers is mostly based on deterministic models, and does not fully consider parameter drift and gain offset in the high-frequency band in the actual system. When the existing method uses a fixed compensation network, it is difficult to balance the dynamic response speed and anti-interference ability: on the one hand, relying too much on empirical adjustment of the zero / pole position easily leads to insufficient phase margin, resulting in overshoot or oscillation when the load changes suddenly; on the other hand, ignoring unstructured uncertainties (such as gain fluctuations caused by PCB parasitic inductance) will cause the risk of high-frequency instability. Summary of the Invention

[0004] In view of the above existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides a design method for an IGBT electronic load controller with uncertainties to solve the problems of insufficient dynamic performance, high-frequency instability, and parameter drift sensitivity of the existing IGBT electronic load controller due to the lack of quantification of structured and unstructured uncertainties.

[0006] To solve the above technical problems, the present invention provides the following technical solutions: In a first aspect, the present invention provides a design method for an IGBT electronic load controller with uncertainties, which includes establishing a small-signal model of an IGBT constant-current drive circuit, decomposing it into an operational amplifier, a drive stage, and an IGBT module, deriving the transfer function of each link, and obtaining the uncompensated open-loop transfer function; Based on the uncompensated open-loop transfer function, setting dynamic performance indicators, constructing an expected open-loop transfer function, and inversely deriving the controller through parameter matching to generate a controller model; Combine the controller model and the uncompensated open-loop transfer function, analyze the structured and unstructured uncertainties, calculate the upper bound of multiplicative uncertainty and determine the weighting function; Input the controller model, the uncompensated open-loop transfer function and the weighting function into the robust Bode plot to verify whether the open-loop frequency curve avoids the forbidden zone, and output a qualified controller by iteratively adjusting and backstepping the controller parameters.

[0007] As a preferred embodiment of the design method of the uncertainty IGBT electronic load controller of the present invention, wherein: obtaining the uncompensated open-loop transfer function includes the following steps, Define the transfer function of the error amplification link based on the open-loop gain characteristic of the operational amplifier, and solve the drive-stage transfer function by combining the equations of the MOSFET gate circuit, the triode base circuit and the output circuit of the drive-stage module; Derive the IGBT module transfer function through the gate-loop current balance equation and the gate-emitter voltage division equation of the IGBT module; Connect the error amplification link transfer function, the drive-stage transfer function, the IGBT module transfer function in series with the sampling resistor to obtain the uncompensated open-loop transfer function.

[0008] As a preferred embodiment of the design method of the uncertainty IGBT electronic load controller of the present invention, wherein: setting the dynamic performance indexes includes defining the frequency-domain targets of the maximum rise time, the maximum overshoot, the minimum velocity error coefficient, the maximum acceleration and the maximum cut-off frequency.

[0009] As a preferred embodiment of the design method of the uncertainty IGBT electronic load controller of the present invention, wherein: constructing the expected open-loop transfer function includes the following steps, Form a transfer function structure including a gain ratio term, a phase compensation term and a bandwidth limitation term by setting the distributions of zeros, low-frequency poles and high-frequency poles; Adjust the zero position and the pole spacing, balance the dynamic response speed and stability, and verify the amplitude condition through the cut-off frequency, and iteratively correct until all frequency-domain constraints are met.

[0010] As a preferred embodiment of the design method of the uncertainty IGBT electronic load controller of the present invention, wherein: the backstepping controller model refers to comparing the expected open-loop transfer function with the uncompensated open-loop transfer function, deriving the frequency domain of the controller model based on the gain matching principle, and optimizing the phase margin and bandwidth characteristics of the controller model by adjusting the proportional gain, the integral time and the zero position.

[0011] As a preferred solution of the design method of the uncertainty IGBT electronic load controller described in the present invention, wherein: the analysis of structured and unstructured uncertainties refers to modeling the parameter fluctuations of the actual system as structured uncertainties, calculating the gain deviation of the transfer function through the nominal value and the extreme value range of the components, modeling the measured gain fluctuations as unstructured uncertainties, and extracting the offset trend in the high-frequency band.

[0012] As a preferred solution of the design method of the uncertainty IGBT electronic load controller described in the present invention, wherein: the determination of the weight function includes the following steps Combining structured and unstructured uncertainties into an overall multiplicative uncertainty bound, and defining a robust stability weight function; Defining a performance weight function based on the sensitivity function and the complementary sensitivity function.

[0013] As a preferred solution of the design method of the uncertainty IGBT electronic load controller described in the present invention, wherein: the iterative adjustment refers to introducing a low-pass filter in the controller model to suppress the high-frequency gain for the risk of high-frequency instability, and adding an integral link to increase the low-frequency gain and adjusting the zero point to provide phase lead for the insufficient dynamic performance.

[0014] In a second aspect, the present invention provides a computer device, including a memory and a processor, where the memory stores a computer program, and wherein: when the computer program is executed by the processor, any step of the design method of the uncertainty IGBT electronic load controller described in the first aspect of the present invention is implemented.

[0015] In a third aspect, the present invention provides a computer-readable storage medium, on which a computer program is stored, and wherein: when the computer program is executed by the processor, any step of the design method of the uncertainty IGBT electronic load controller described in the first aspect of the present invention is implemented.

[0016] The beneficial effects of the present invention are as follows: The drive circuit is decomposed into three independent links: error amplification, drive stage, and IGBT module. The transfer functions of each link are accurately derived through the gate loop current balance equation and the gate-emitter voltage division equation, and an uncompensated open-loop model including the influence of parasitic parameters is established, providing an accurate benchmark for uncertainty analysis; Based on the dynamic performance index, a fourth-order expected open-loop transfer function including a phase compensation term is constructed. By optimizing the zero position and controlling the pole spacing, the phase margin is improved and the acceleration constraint is achieved at the cut-off frequency, solving the contradiction between overshoot and response speed; The parameter fluctuation is modeled as structured uncertainty, and the measured gain offset is modeled as unstructured. The robust stability weight function is defined through the fusion of multiplicative uncertainty boundaries, improving the gain margin of the controller to the change of the gate-emitter parasitic capacitance of the IGBT; The avoidance ability of the open-loop frequency curve is verified through the forbidden zone boundary condition, and combined with low-pass filtering, the dynamic response time is shortened. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a flowchart for establishing the uncompensated open-loop transfer function in Embodiment 1.

[0019] Figure 2 It is a flowchart for constructing the expected open-loop transfer function in Embodiment 1.

[0020] Figure 3 It is a flowchart for uncertainty analysis and weight function determination in Embodiment 1.

[0021] Figure 4 It is a flowchart for robust verification and parameter adjustment in Embodiment 1. Detailed Embodiments

[0022] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the detailed embodiments of the present invention will be described in detail below with reference to the drawings of the specification.

[0023] Many specific details are set forth in the following description in order to provide a thorough understanding of the present invention, but the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0024] Second, the so-called "one embodiment" or "embodiment" herein refers to specific features, structures or characteristics that may be included in at least one implementation manner of the present invention. The appearances of "in one embodiment" in different places in this specification do not all refer to the same embodiment, nor are they separate or alternative embodiments that exclude each other with other embodiments.

[0025] Embodiment 1, referring to Figures 1 to 4 , this embodiment provides a design method for an uncertain IGBT electronic load controller, including the following steps: S1. According to the circuit topology, decompose the IGBT constant current drive circuit into an operational amplifier error amplification link, a drive stage module, and an IGBT working module.

[0026] Furthermore, the operational amplifier error amplification link obtains the amplified output error voltage by receiving the difference between the load current sampling signal and the reference signal; based on the open-loop gain characteristic of an ideal operational amplifier, the open-loop gain is used as the transfer function of the error amplification link to determine the amplification ratio of the amplified output error voltage, and the expression is: ; Among them, represents the transfer function of the operational amplifier error amplification link, represents the open-loop gain of the operational amplifier, that is, the amplification multiple of the input difference voltage by the operational amplifier in the open-loop state.

[0027] The drive stage module is a drive stage circuit composed of a MOSFET and a triode. Based on the small-signal equivalent circuit of the drive stage, the input voltage (the output error voltage of the error amplification link) and the output voltage are defined, and combined with the base current of the triode and the gate-source voltage of the MOSFET, three equations of the MOSFET gate loop, the triode base loop, and the drive stage output loop are written according to Kirchhoff's law, specifically as follows: The MOSFET gate loop describes the charge and discharge of the gate-source parasitic capacitance and the contribution of the transconductance to the current. Combining the current gain of the triode, the relationship between the gate-source voltage, the base current of the triode, and the output voltage of the drive stage is established, and the expression is: ; Among them, represents the complex frequency variable (Laplace variable), which is used for the differential operation of time, represents the gate-source parasitic capacitance of the MOSFET, that is, the equivalent capacitance between the gate and the source, represents the gate-source voltage of the MOSFET, represents the transconductance coefficient of the MOSFET, that is, the control ability of the gate-source voltage to the drain current, represents the current amplification coefficient, that is, the gain from the base current to the collector current, Represents the base current of the triode, Represents the output voltage of the drive stage, Represents the resistance of the output loop of the drive stage, used for current limiting or voltage division.

[0028] The base loop of the triode defines the voltage balance relationship between the base current, the input voltage, and the output voltage. The expression is: ; Among them, Represents the output resistance when the output is short-circuited by AC, that is, the equivalent resistance between the base and the emitter, Represents the input voltage of the drive stage, which is the output error voltage of the error amplification link.

[0029] The output loop of the drive stage refers to the relationship between the gate-source voltage and the base current of the triode through the output impedance of the drive stage. The expression is: ; Among them, Represents the internal feedback resistance of the drive stage, used for dynamic compensation and stability adjustment.

[0030] By solving the expressions of the MOSFET gate loop, the triode base loop, and the drive stage output loop, the drive stage transfer function between the input and output of the drive stage is obtained. The expression is: ; Among them, Represents the transfer function of the drive stage, defined as the ratio of the output voltage of the drive stage to the input voltage of the drive stage, Represents the high-frequency gain term of the triode amplification effect and the MOSFET transconductance coefficient, Represents the low-frequency gain term of the DC amplification ability of the drive stage, Represents the pole time constant, which is determined by the triode input impedance and the gate-source capacitance and affects the bandwidth of the drive stage, Represents the static damping term of the steady-state response that synthesizes the transconductance coefficient, resistance of the MOSFET, and the impedance of the triode.

[0031] Furthermore, 、 、 and The expressions are as follows: ; ; ; .

[0032] Based on the IGBT equivalent circuit, it is clear that the input voltage of the IGBT module is the output voltage of the drive stage, and the output current is the collector current. Combining with the gate-emitter voltage, the Kirchhoff's law is used to write the gate loop current balance equation and the gate-emitter voltage division equation as follows: The expression of the gate loop current balance equation is: ; Among them, represents the IGBT collector current (output current), represents the sampling resistor, which is used to detect the collector current and convert it into a voltage signal for feedback, represents the gate series resistor, which limits the gate current and suppresses high-frequency oscillation, represents the gate-emitter parasitic capacitance of the IGBT, represents the gate parallel resistor, which is used to adjust the gate voltage division and improve the dynamic response, represents the transconductance coefficient of the IGBT, represents the gate-emitter voltage of the IGBT, represents the total gate loop current (including the capacitor charge and discharge current and the transconductance current).

[0033] The expression of the gate-emitter voltage division equation is: ; By solving the gate loop current balance equation and the gate-emitter voltage division equation, combined with the parasitic parameters (such as the gate-emitter parasitic capacitance of the IGBT, the resistor , , and the transconductance coefficient of the IGBT), the transfer function of the IGBT module is derived, and the expression is: ; Among them, represents the transfer function of the IGBT module, represents the high-frequency dominant term, which is determined by the gate capacitance and the resistor network, represents the intermediate-frequency dynamic term, that is, the coupling effect of the transconductance coefficient of the IGBT and the resistor network, represents the steady-state current gain dominated by the product of the transconductance coefficient of the IGBT and the resistor, represents the pole position term, which determines the frequency of the denominator quadratic pole and affects the IGBT bandwidth, represents the static damping term that reflects the steady-state influence of the total resistance.

[0034] By solving the transfer function of the error amplification link, the transfer function of the drive stage, and the transfer function of the IGBT module of the electronic load drive circuit, and connecting them in series with the sampling resistor, the uncompensated open-loop transfer function is obtained, and the expression is: ; Among them, represents the open-loop transfer function without compensation.

[0035] Furthermore, , , , and have the following expressions: ; ; ; ; .

[0036] S2. Based on the actual application scenarios and hardware limitations of the IGBT constant-current drive circuit, define the dynamic performance indexes of the maximum rise time, maximum overshoot, minimum velocity error coefficient, maximum acceleration, and maximum cut-off frequency.

[0037] Furthermore, in this embodiment, the maximum rise time refers to the maximum time required for the load current to rise from 10% of the initial value to 90% of the steady state, and the expression is: ; wherein, represents the maximum rise time, which is used to measure the response speed of the system to load mutations or command changes, and is the upper limit of the dynamic performance that constrains the controller. represents the cut-off frequency, that is, the frequency at which the magnitude of the open-loop transfer function drops to 1, which determines the tracking ability of high-frequency signals and the noise suppression ability. The larger the cut-off frequency, the faster the response, but it is necessary to avoid the amplification of high-frequency noise caused by too high a bandwidth. represents the system dynamic characteristic parameter. represents the proportional coefficient. and represent the system damping parameters, both of which are used to adjust the pole-zero distribution of the expected open-loop function. For example, ≥2, ≥2 is used to control the position of the low-frequency poles and suppress high-frequency noise. =2.5, =2 is used to adjust the spacing of the high-frequency poles, limit the bandwidth, and ensure stability.

[0038] The overshoot refers to the percentage by which the peak value of the current response exceeds the steady-state value. Limiting the maximum overshoot is to prevent the IGBT from being damaged by thermal stress due to instantaneous overcurrent, or the load-sensitive components (such as LEDs, batteries) from being damaged; the velocity error coefficient refers to the reciprocal of the steady-state velocity error, and the minimum velocity error coefficient is to ensure the tracking accuracy of the ramp command (such as a linearly changing current command), and the expression is: ; Among them, represents the speed error coefficient.

[0039] The maximum acceleration refers to the upper limit of the acceleration that defines the change in load current, which is used to limit the rate of sudden change of current and avoid electromagnetic interference or breakdown of power devices (such as MOSFETs and capacitors) caused by current spikes. The expression is: ; Among them, represents the maximum acceleration.

[0040] The maximum cut-off frequency refers to the frequency at which the open-loop gain drops to 0 dB, which determines the system bandwidth.

[0041] Based on the dynamic performance indicators, set the frequency-domain targets of the cut-off frequency, phase margin, and maximum acceleration as the frequency-domain characteristic constraints of the expected open-loop transfer function. Combining , , , and , construct the zeros, low-frequency poles, and high-frequency poles of the expected open-loop transfer function; integrate the zeros, low-frequency poles, and high-frequency poles to obtain the expected open-loop transfer function. The expression is: ; Among them, represents the expected open-loop transfer function.

[0042] Substitute the complex frequency variable into the expected open-loop transfer function to calculate the magnitude of the complex frequency variable. If the magnitude is equal to 1, the cut-off frequency design is reasonable; if not, adjust or to correct the gain; decompose the phase angle contribution terms of the expected open-loop transfer function and calculate the total phase margin. If the total phase margin is insufficient, optimize by increasing (enhancing the zero-phase lead) or decreasing (reducing the low-frequency pole-phase lag); estimate the acceleration energy through frequency-domain integration, analyze the contributions of the low-frequency, middle-frequency, and high-frequency segments in segments. If the acceleration exceeds the limit, reduce (reducing the middle-frequency gain) or the cut-off frequency (narrowing the bandwidth); when all conditions are met, obtain a qualified expected open-loop transfer function.

[0043] Furthermore, the magnitude equal to 1 is the golden rule for cut-off frequency design, which is jointly determined by control theory definition and engineering practice.

[0044] Combining the expected open-loop transfer function and the uncompensated open-loop transfer function, the expression of the controller model is deduced as: ; Among them, represents the controller model.

[0045] S3. Divide the actual system into structured uncertainty and unstructured uncertainty according to the controller model, and the expressions are as follows: ; ; where, represents the frequency response of the actual system of the th structured uncertainty, represents the number of actual system models, represents the frequency variable, represents the frequency response of the nominal system, represents the structured uncertainty, represents the number of actual system frequency responses, represents the th frequency response of the actual system with structured and unstructured uncertainties, represents the unstructured uncertainty, represents the multiplicative uncertainty bound including structured and unstructured uncertainties.

[0046] Further explanation: Structured uncertainty refers to obtaining the nominal value and variation range of the gate-emitter capacitance of the IGBT through the component data sheet and converting it into the fluctuation of the gate-emitter capacitance of the IGBT in the IGBT transfer function; Unstructured uncertainty refers to obtaining the measured gain fluctuation range through the frequency-domain sweep experiment.

[0047] Combine structured and unstructured uncertainties into an overall multiplicative uncertainty bound through structured contribution and unstructured contribution, and the expression is: ; where, represents the upper bound of the uncertainty of the unstructured uncertainty at the frequency .

[0048] Further explanation: Structured contribution refers to substituting the extreme values of the gate-emitter capacitance of the IGBT into the IGBT transfer function to calculate the gain deviation at different frequencies; Unstructured contribution refers to extracting the trend of the gain offset in the high-frequency band based on the measured gain fluctuation range of the frequency sweep.

[0049] Define the robust stability weight function to meet the conditions according to the upper bound of the uncertainty, and the expression is: ; where, represents the robust stability weight function, that is, the maximum allowable uncertainty amplitude at each frequency.

[0050] Based on the sensitivity-based dynamic performance constraints, define the satisfaction condition of the performance weight function, and the expression is: ; Wherein, represents the performance weight function, which forces the sensitivity function to meet the dynamic index, represents the frequency-domain representation of the digital controller in the control model, which is used to adjust the dynamic behavior of the system, ensure closed-loop stability (suppress oscillations) and dynamic performance (such as tracking accuracy, anti-interference ability).

[0051] S4. Based on the controller model and the uncompensated open-loop transfer function, calculate the open-loop frequency response of the nominal system, and the expression is: ; Wherein, represents the open-loop frequency response of the closed-loop system.

[0052] Further explanation, the open-loop frequency response refers to the response characteristics in the frequency domain of the series combination of the nominal system and the controller. The phase margin and gain margin of the system are judged through the Bode plot or Nyquist plot to evaluate the closed-loop stability.

[0053] By decomposing the open-loop frequency response of the nominal system into the amplitude-frequency characteristic and the phase-frequency characteristic, generate the Bode plot (amplitude-frequency curve and phase-frequency curve) of the nominal open-loop frequency response; define the forbidden zone boundary of robust stability, and the expression is: ; Wherein, represents the complementary sensitivity function.

[0054] Further explanation, the complementary sensitivity function is complementary to the sensitivity function, and focuses on the sensitivity of the closed-loop system to model uncertainties. The expression is: ; Based on the forbidden zone boundary of robust stability, plot the curve on the Bode plot as the upper limit of the stability forbidden zone; combine the robust stability weight function and the performance weight function with the complementary sensitivity function and the sensitivity function respectively, and define the performance robustness forbidden zone boundary, and the expression is: ; Wherein, represents the sensitivity function.

[0055] Further explanation, the sensitivity function reflects the ability of the closed-loop system to suppress input disturbances. The expression is: ; Based on the performance robustness forbidden zone boundary, superimpose the The curve, as the upper limit of the performance forbidden zone; verify the nominal system frequency response according to the upper limit of the stability forbidden zone and the upper limit of the performance forbidden zone, and confirm that the open-loop frequency response curve of the nominal system avoids the curve and the curve; based on the phase-frequency characteristic of the nominal open-loop frequency response, calculate the phase margin at the cut-off frequency to measure the relative stability of the system at the gain crossover frequency (cut-off frequency); based on the amplitude-frequency characteristic of the nominal open-loop frequency response, calculate the gain margin at the phase crossover frequency to measure the tolerance of the system to gain changes; combine the amplitude-frequency verification, phase margin verification and gain margin verification to generate the verification result (pass / fail) and locate the problem frequency band.

[0056] If the curve enters above the curve, the system may become unstable due to high-frequency uncertainty. At this time, add high-frequency filtering poles and add a low-pass filter term to the controller model to suppress the high-frequency gain. At the same time, reduce the proportional gain to reduce the amplification factor of the controller in the medium and high frequency bands; if the curve enters above, the dynamic performance of the system does not meet the standard. Increase the integral time to increase the low-frequency gain and force the curve to approach 0. At the same time, add a zero point to the controller model to improve the phase margin; if the phase margin is insufficient, adjust the zero point position, move the zero point of the controller model to the low frequency to provide phase lead, and at the same time reduce the cut-off frequency and reduce the bandwidth in exchange for a larger phase margin; based on the adjustment result, obtain a qualified controller and meet all dynamic performance and stability indicators.

[0057] This embodiment also provides a computer device, which is applicable to the case of the design method of the uncertain IGBT electronic load controller, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the design method of the uncertain IGBT electronic load controller proposed in the above embodiment.

[0058] The computer device may be a terminal, which includes a processor, a memory, a communication interface, a display screen, and an input device connected via a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a carrier network, NFC (Near Field Communication), or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or buttons, a trackball, or a touchpad provided on the housing of the computer device, or an external keyboard, touchpad, or mouse, etc.

[0059] This embodiment also provides a storage medium, on which a computer program is stored. When the program is executed by a processor, it implements the method for designing an uncertainty IGBT electronic load controller as proposed in the above embodiment; the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Red-Only Memory (PROM), Read-Only Memory (ROM), magnetic memory, flash memory, a magnetic disk, or an optical disc.

[0060] In summary, the present invention achieves the following: decomposing the drive circuit into three independent parts, namely error amplification, drive stage, and IGBT module; accurately deriving the transfer functions of each part through the gate-loop current balance equation and gate-emitter voltage division equation, and establishing an uncompensated open-loop model considering the influence of parasitic parameters to provide an accurate benchmark for uncertainty analysis; constructing a fourth-order expected open-loop transfer function with a phase compensation term based on dynamic performance indicators, and realizing the improvement of phase margin and acceleration constraint at the cut-off frequency through zero-point position optimization and pole-spacing control to solve the contradiction between overshoot and response speed; modeling parameter fluctuations as structured uncertainties and measured gain offsets as unstructured uncertainties, and defining a robust stability weight function through the fusion of multiplicative uncertainty boundaries to improve the gain margin of the controller against changes in the gate-emitter parasitic capacitance of the IGBT; verifying the avoidance ability of the open-loop frequency curve through forbidden zone boundary conditions and combining with low-pass filtering to shorten the dynamic response time.

[0061] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. Design method for an IGBT electronic load controller with uncertainty, characterized in that: including, establish a small-signal model of the IGBT constant-current drive circuit, decompose it into an operational amplifier, a drive stage, and an IGBT module, deduce the transfer functions of each link, and obtain the uncompensated open-loop transfer function; Based on the uncompensated open-loop transfer function, set dynamic performance indicators, construct an expected open-loop transfer function, deduce the controller by parameter matching, and generate a controller model; Combined with the controller model and the uncompensated open-loop transfer function, analyze structured and unstructured uncertainties, calculate the upper bound of multiplicative uncertainty and determine the weighting function; Input the controller model, the uncompensated open-loop transfer function, and the weighting function into the robust Bode plot, verify whether the open-loop frequency curve avoids the forbidden zone, and output a qualified controller by iteratively adjusting and deducing the controller parameters.

2. The design method of the uncertainty IGBT electronic load controller according to claim 1, characterized in that: The obtaining of the uncompensated open-loop transfer function includes the following steps: Define the transfer function of the error amplification link based on the open-loop gain characteristic of the operational amplifier, and solve the drive-stage transfer function by combining the equations of the MOSFET gate circuit, the transistor base circuit, and the output circuit of the drive-stage module; Deduce the IGBT module transfer function through the gate-loop current balance equation and the gate-emitter voltage division equation of the IGBT module; Connect the error amplification link transfer function, the drive-stage transfer function, the IGBT module transfer function in series with the sampling resistor to obtain the uncompensated open-loop transfer function.

3. The design method of the uncertainty IGBT electronic load controller according to claim 2, characterized in that: The setting of the dynamic performance indicators includes defining the frequency-domain targets of the maximum rise time, the maximum overshoot, the minimum velocity error coefficient, the maximum acceleration, and the maximum cut-off frequency.

4. The method for designing an uncertain IGBT electronic load controller according to claim 3, wherein: The construction of the expected open-loop transfer function includes the following steps: Form a transfer function structure including a gain ratio term, a phase compensation term, and a bandwidth limitation term by setting the distribution of zeros, low-frequency poles, and high-frequency poles; Adjust the zero position and the pole spacing, balance the dynamic response speed and stability, and verify the amplitude condition through the cut-off frequency, and iteratively correct until all frequency-domain constraints are met.

5. The design method of the uncertainty IGBT electronic load controller according to claim 4, characterized in that: The deduced controller model refers to comparing the expected open-loop transfer function with the uncompensated open-loop transfer function, deducing the frequency domain of the controller model based on the gain matching principle, and optimizing the phase margin and bandwidth characteristics of the controller model by adjusting the proportional gain, the integral time, and the zero position.

6. The design method of the uncertainty IGBT electronic load controller according to claim 5, characterized in that: The analysis of structured and unstructured uncertainties refers to modeling the parameter fluctuations of the actual system as structured uncertainties, calculating the gain deviation of the transfer function through the nominal value and the extreme value range of the components, modeling the measured gain fluctuations as unstructured uncertainties, and extracting the high-frequency segment offset trend.

7. The design method of the uncertainty IGBT electronic load controller according to claim 6, characterized in that: The determination of the weighting function includes the following steps: Combine structured and unstructured uncertainties into the overall multiplicative uncertainty boundary and define the robust stability weighting function; Define the performance weighting function based on the sensitivity function and the complementary sensitivity function.

8. The design method of the uncertainty IGBT electronic load controller according to claim 7, characterized in that: The iterative adjustment refers to introducing a low-pass filter into the controller model to suppress the high-frequency gain for the high-frequency instability risk, increasing the integral link to enhance the low-frequency gain and adjusting the zero to provide phase lead for the insufficient dynamic performance.

9. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that: When the processor executes the computer program, it realizes the steps of the uncertainty IGBT electronic load controller design method according to any one of claims 1 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, it implements the steps of the design method of the uncertain IGBT electronic load controller according to any one of claims 1 to 8.

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