A double closed loop control method of high-voltage DC / DC converter

Abstract

The application relates to the technical field of converter control, in particular to a double-closed-loop control method for a high-voltage DC / DC converter, which comprises the following steps: collecting output parameters of each feedback control loop of the high-voltage DC / DC converter at each moment; determining characteristic coefficients of each feedback control loop at each moment; setting an adjustment moment every fixed time interval; determining each characteristic interval of each feedback control loop at the current adjustment moment; obtaining fluctuation influence characteristic values of each characteristic interval of each feedback control loop at the current adjustment moment; fusing the fluctuation influence characteristic values of all characteristic intervals of each feedback control loop at the current adjustment moment and the characteristic coefficients to obtain response coefficients of each feedback control loop at the current adjustment moment, so as to adjust proportional coefficients and integral coefficients when PI control algorithm is used to control each feedback control loop. The application improves the double-closed-loop control precision of the converter.

Description

Technical Field

[0001] This application relates to the field of converter control technology, specifically to a dual closed-loop control method for a high-voltage DC / DC converter. Background Technology

[0002] High-voltage DC / DC converters are core devices for power conversion, with their basic function being DC voltage conversion. They are widely used in energy conversion and power management, achieving efficient and stable power conversion and ensuring the stability and accuracy of power supply to equipment. However, traditional open-loop control strategies for high-voltage DC / DC converters are insufficient to meet application requirements. Currently, a dual closed-loop control strategy is commonly used. The voltage loop stabilizes the output voltage, while the current loop tracks current commands and suppresses disturbances during operation. This addresses the issues of non-adjustable output voltage and large fluctuations in output voltage with input voltage inherent in traditional high-voltage DC / DC converter control strategies, improving the stability and accuracy of power supply to equipment. Furthermore, corresponding current-limiting protection functions are incorporated to maintain the safe and stable operation of the equipment.

[0003] In the process of controlling a high-voltage DC / DC converter using a dual voltage and current closed-loop system, the actual control deviation of the converter is relatively large due to the influence of various interference factors, affecting the control accuracy of the high-voltage DC / DC converter. In the traditional voltage and current dual closed-loop control process, the dynamic changes in the high-voltage DC / DC converter during real-time operation lead to a large difference between the result of the dual closed-loop control and the target value. That is, the dynamic fluctuation characteristics of the load and input voltage are ignored, resulting in a low response speed of the voltage and current loops when the load and input fluctuate. This causes a large deviation between the control parameters of the high-voltage DC / DC converter and the actual operating conditions, ultimately leading to increased converter output ripple and failing to meet the high-precision requirements of precision equipment for high-voltage power supply. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a dual closed-loop control method for a high-voltage DC / DC converter, thereby resolving the existing issues.

[0005] The dual closed-loop control method for a high-voltage DC / DC converter disclosed in this application adopts the following technical solution:

[0006] One embodiment of this application provides a dual closed-loop control method for a high-voltage DC / DC converter, the method comprising the following steps:

[0007] The output parameters of each feedback control loop of the high-voltage DC / DC converter are collected at each moment.

[0008] Based on the difference between the output parameters at each moment and the rated output parameters, the characteristic coefficients of each feedback control loop at each moment are determined; the adjustment time is set at fixed time intervals.

[0009] Analyze the abnormal conditions of the characteristic coefficients of each feedback control loop at all times between the current adjustment time and its adjacent adjustment times, divide the time period between the current adjustment time and its adjacent adjustment times, and determine the characteristic intervals of each feedback control loop at the current adjustment time.

[0010] By comparing the numerical distribution differences between all output parameters of each feedback control loop in each characteristic interval at the current adjustment time and all output parameters of another feedback control loop in the same characteristic interval, the fluctuation impact characteristic value of each feedback control loop in each characteristic interval at the current adjustment time is determined.

[0011] By integrating the fluctuation influence characteristic values ​​of all characteristic intervals of each feedback control loop at the current adjustment time with the characteristic coefficients, the response coefficient of each feedback control loop at the current adjustment time is obtained, so as to adjust the proportional coefficient and integral coefficient when using the PI control algorithm to control each feedback control loop.

[0012] In one embodiment, determining the characteristic coefficients of each feedback control loop at each time step includes:

[0013] For each feedback control loop, the difference between the output parameter and the rated output parameter at each time step is calculated, and the ratio of the difference to the rated output parameter is used as the characteristic coefficient of each feedback control loop at each time step.

[0014] In one embodiment, determining the characteristic intervals of each feedback control loop at the current adjustment time includes:

[0015] The time interval between the current adjustment time and its adjacent previous adjustment time is recorded as the adjustment period. The abrupt change points of the characteristic coefficients of each feedback control loop at all times within the adjustment period are detected. Based on all the abrupt change points of each feedback control loop within the adjustment period, the corresponding characteristic intervals of each feedback control loop are obtained.

[0016] In one embodiment, each characteristic interval corresponding to each feedback control loop is the time interval between each abrupt change point of each feedback control loop within the adjustment period and the current adjustment time.

[0017] In one embodiment, the feedback control loop includes a voltage feedback control loop and a current feedback control loop.

[0018] In one embodiment, determining the fluctuation influence characteristic value includes:

[0019] For the y-th characteristic interval of the voltage feedback control loop at the current adjustment time, calculate the mean, range, and dispersion of the output parameters at all times, as well as the mean, range, and dispersion of the characteristic coefficients at all times, and arrange them in a fixed order to form the characteristic sequence of the y-th characteristic interval of the voltage feedback control loop at the current adjustment time.

[0020] Correspondingly, the mean, range, and dispersion of the output parameters of the current feedback control loop at all times in the y-th characteristic interval are calculated, as well as the mean, range, and dispersion of the characteristic coefficients at all times, forming a comparative characteristic sequence of the voltage feedback control loop in the y-th characteristic interval at the current adjustment time.

[0021] Based on the metric distance between the feature sequence and the comparison feature sequence of the voltage feedback control loop in the y-th feature interval at the current adjustment time, and the similarity between the output parameters of the voltage feedback control loop in the y-th feature interval at the current adjustment time and the output parameters of the current feedback control loop, the fluctuation influence characteristic value of the voltage feedback control loop in the y-th feature interval at the current adjustment time is determined.

[0022] The fluctuation influence characteristic value of the voltage feedback control loop in the y-th characteristic interval at the current adjustment time is positively correlated with the metric distance and negatively correlated with the similarity.

[0023] In one embodiment, obtaining the response coefficients of each feedback control loop at the current adjustment time includes:

[0024] Calculate the average of the absolute values ​​of the characteristic coefficients of each feedback control loop at all times within each characteristic interval at the current adjustment time. Calculate the product of the normalized value of the fluctuation influence characteristic value of each feedback control loop at each characteristic interval at the current adjustment time and the average value. The response coefficient is the sum of the products of each feedback control loop at all characteristic intervals at the current adjustment time.

[0025] In one embodiment, the proportional and integral coefficients used in the adjustment when controlling each feedback control loop using a PI control algorithm include:

[0026] For the voltage feedback control loop, the maximum value of the proportional coefficient and the maximum value of the integral coefficient of the PI control algorithm at each historical adjustment time are obtained respectively; the difference between the maximum value of the proportional coefficient and the initial value of the proportional coefficient is calculated and multiplied by the response coefficient of the voltage feedback control loop at the current adjustment time; the sum of the result of the multiplication and the initial value of the proportional coefficient is used as the adjusted proportional coefficient of the voltage feedback control loop at the current adjustment time.

[0027] Accordingly, the integral coefficient of the voltage feedback control loop after adjustment at the current adjustment time is obtained by using the same calculation method as the proportional coefficient adjusted by the voltage feedback control loop at the current adjustment time.

[0028] Based on the maximum proportional and integral coefficients of the PI control algorithm in the historical adjustment time of the current feedback control loop, and combined with the response coefficient of the current feedback control loop at the current adjustment time, the adjusted proportional and integral coefficients of the current feedback control loop at the current adjustment time are determined.

[0029] In one embodiment, the proportional coefficient adjusted by the current feedback control loop at the current adjustment time The expression is:

[0030] In the formula, This represents the initial value of the proportional coefficient for the PI control algorithm corresponding to the current feedback control loop. This represents the maximum proportional gain of the PI control algorithm in the current feedback control loop during historical adjustment periods. This represents the response coefficient of the current feedback control loop at the current adjustment moment.

[0031] In one embodiment, the integral coefficient of the current feedback control loop after adjustment at the current adjustment time The expression is:

[0032] In the formula, These are the initial values ​​of the integral coefficients for the PI control algorithm corresponding to the current feedback control loop. This represents the maximum integral coefficient of the PI control algorithm in the current feedback control loop during historical adjustment times.

[0033] This application has at least the following beneficial effects:

[0034] This application, by real-time acquisition of the output parameters of each feedback control loop and analysis of the differences from the rated output parameters, can accurately calculate the characteristic coefficients at each moment, thereby effectively improving the response speed of the feedback control loop to load changes and input fluctuations, and ensuring accurate identification of load abrupt changes or input voltage fluctuations. By performing distribution difference analysis on the output parameters within each characteristic interval, the degree of output parameter fluctuation in each characteristic interval can be more accurately identified, which helps to optimize the adjustment strategy of each feedback control loop and avoid voltage and current fluctuations caused by over-adjustment or delayed response, thus effectively improving the stability and output accuracy of the converter. In addition, by real-time analysis of the characteristic interval of each feedback control loop and combining the characteristic coefficients with the fluctuation impact characteristic values, the state of the converter can be comprehensively monitored, improving the accuracy and suitability of parameter determination in the PI control algorithm, effectively improving the dynamic response speed of the converter to load changes and input voltage fluctuations, avoiding long-term instability caused by steady-state error accumulation, enhancing the safety and reliability of the converter, reducing the impact of dynamic fluctuation characteristic differences on control during the operation of high-voltage DC / DC converters, and improving the dual closed-loop control accuracy of high-voltage DC / DC converters. Attached Figure Description

[0035] To more clearly illustrate the technical solutions and advantages 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.

[0036] Figure 1 A flowchart illustrating the steps of a dual closed-loop control method for a high-voltage DC / DC converter provided in this application;

[0037] Figure 2 This is a flowchart showing the adjustment process of the proportional and integral coefficients of the PI control algorithm at the current adjustment time. Detailed Implementation

[0038] To further illustrate the technical means and effects adopted by this application to achieve the intended purpose of the invention, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a dual closed-loop control method for a high-voltage DC / DC converter proposed in this application. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0040] The following description, in conjunction with the accompanying drawings, details the specific scheme of the dual closed-loop control method for a high-voltage DC / DC converter provided in this application.

[0041] This application provides an embodiment of a dual-closed-loop control method for a high-voltage DC / DC converter. Specifically, it provides the following dual-closed-loop control method for a high-voltage DC / DC converter. Please refer to [link to relevant documentation]. Figure 1 The method includes the following steps:

[0042] Step S001: Collect the output parameters of each feedback control loop of the high-voltage DC / DC converter at each time and perform preprocessing.

[0043] In this embodiment, the control result of the high-voltage DC / DC converter is based on the ROYER oscillator circuit topology and is controlled in real time through a voltage and current dual closed-loop control circuit. The dual closed-loop control circuit is based on an operational amplifier. By sampling the output voltage and output current and comparing them with the external control signal, it controls the switching on and off of the transistors, thereby adjusting the duty cycle of the power switching transistors to control the output voltage.

[0044] The dual-loop control of the high-voltage DC / DC converter uses two closed loops, namely two feedback control loops, for dynamic adjustment: a voltage feedback control loop and a current feedback control loop, abbreviated as the voltage loop and the current loop. In this embodiment, voltage and current sensors are used to collect the output parameters of the voltage and current loops in real time. Based on the collected output parameters, the operating status of the high-voltage DC / DC converter is monitored and fed back, thereby monitoring and analyzing the operating status characteristics of the dual-loop control of the high-voltage DC / DC converter. In this embodiment, the output parameters of the voltage and current loops are collected synchronously, and the collection time interval is set to 0.1s. Implementers can set this according to their actual situation; this embodiment does not impose any restrictions on this.

[0045] Considering the complex environment in which high-voltage DC / DC converters operate, noise interference occurs during the acquisition of monitoring data, reducing the quality of the acquired data. Therefore, the output parameters of the acquired voltage loop and current loop are used as inputs, and a mean filter is used for filtering and noise reduction to obtain the noise-reduced voltage and current data. The specific filtering and noise reduction process is a known existing technology, and implementers can choose other feasible filtering and noise reduction algorithms.

[0046] During the operation of high-voltage DC / DC converters, environmental interference can cause operational deviations. Furthermore, in the voltage-current dual-loop control process, the differences in the dynamic fluctuation characteristics of the load and input voltage lead to significant discrepancies between the control results and the actual state, thus affecting the stability of the converter's operation. Based on this analysis, this application comprehensively considers the dynamic differences in the operating state of the high-voltage DC / DC converter, analyzes the response characteristics of the dual-loop control process, and dynamically optimizes and adjusts the control parameters based on the analysis results to achieve precise control of the converter.

[0047] Step S002: Based on the difference between the output parameters at each time point and the rated output parameters, determine the characteristic coefficients of each feedback control loop at each time point; set the adjustment time at fixed time intervals.

[0048] Because the dynamic fluctuation characteristics of load and input parameters vary significantly across different time periods during converter operation, the voltage and current dual-loop control cannot respond promptly to these variations, resulting in poor converter control performance. Therefore, this paper proposes a dynamic optimization and adjustment process for the dual-loop control of high-voltage DC / DC converters to address the dynamic fluctuation characteristics at different stages of operation, thereby improving the accuracy of the voltage and current dual-loop control. Specifically:

[0049] In the operation of the high-voltage DC / DC converter, this embodiment sets adjustment times, specifically every 5 minutes, meaning the time interval between adjacent adjustment times is 5 minutes. The implementer can set the time interval between adjacent adjustment times according to actual conditions; this embodiment does not impose any restrictions. The time interval between adjacent adjustment times is considered as an adjustment cycle. Further, for the output parameters of each feedback control loop at each moment in each adjustment cycle, the difference between the output parameter acquired at each acquisition moment and the corresponding rated output parameter is calculated. The ratio of this difference to the rated output parameter is used as the characteristic coefficient of each feedback control loop at each moment. The larger the characteristic coefficient, the greater the possibility of instantaneous overshoot during the control process compared to the stable output parameter value. The sequence of characteristic coefficients of each feedback control loop at all moments in each adjustment cycle, arranged according to the corresponding acquisition time order, is used as the characteristic coefficient sequence for each feedback control loop in each adjustment cycle. This characteristic coefficient sequence reflects the overshoot characteristics during the converter's operation control process.

[0050] Step S003: Analyze the abnormality of the characteristic coefficients of each feedback control loop at all times between the current adjustment time and its adjacent adjustment times, divide the time period between the current adjustment time and its adjacent adjustment times, and determine the characteristic intervals of each feedback control loop at the current adjustment time.

[0051] Because the load and input parameters fluctuate dynamically under the dual closed-loop control of voltage and current, the current control response is first achieved through the inner current loop, and then the voltage stabilization control is achieved through the outer voltage loop. Therefore, the converter achieves stable output through the coordinated control of voltage and current. However, under different dynamic fluctuations, the coordinated control of voltage and current may differ, that is, the response to the control of the impact of dynamic fluctuations is relatively lagging.

[0052] Based on the above analysis, for the adjustment period corresponding to the current adjustment time and its adjacent previous adjustment time, the characteristic coefficient sequences of each feedback control loop are used to obtain each abrupt change point in the characteristic coefficient sequence using a mutation point detection algorithm. The acquisition time corresponding to each mutation point is taken as the characteristic time of the dynamic fluctuation response change. For each feedback control loop, the time interval between each characteristic time and the current adjustment time is obtained, which is taken as the characteristic interval of the dynamic fluctuation response change of each feedback control loop at the current adjustment time. The characteristic interval is the time interval of the deviation response change of the converter output control under the influence of dynamic fluctuations up to the current adjustment time. The mutation point detection algorithm is a well-known existing technology, and the specific process will not be described in detail.

[0053] Step S004: By comparing the numerical distribution differences between all output parameters of each feedback control loop in each characteristic interval at the current adjustment time and all output parameters of another feedback control loop in the same characteristic interval, the fluctuation influence characteristic value of each feedback control loop in each characteristic interval at the current adjustment time is determined.

[0054] Considering the coordination and consistency of voltage and current closed-loop control, a comparative analysis of the output parameter characteristics within different characteristic intervals is conducted. Specifically, for each characteristic interval determined by each feedback control loop, the characteristic values ​​of the output parameters within each characteristic interval are calculated. Taking the y-th characteristic interval of the voltage feedback control loop at the current adjustment time as an example, the mean, range, and dispersion of the output parameters at all times within the y-th characteristic interval, as well as the mean, range, and dispersion of the characteristic coefficients at all times, are calculated and arranged in a fixed order to form the characteristic sequence of the voltage feedback control loop at the y-th characteristic interval of the current adjustment time. Each characteristic value in the characteristic sequence reflects the numerical distribution of the output parameters of the voltage feedback control loop within the y-th characteristic interval of the current adjustment time. Implementers can choose other existing calculation methods that can reflect the numerical distribution, such as mode, quartiles, kurtosis, etc., and this embodiment does not impose any restrictions on this. The dispersion can be calculated using variance, standard deviation, coefficient of variation, etc., and this embodiment uses variance as the calculation method for dispersion.

[0055] Accordingly, for the y-th characteristic interval, the mean, range, and dispersion of the output parameters of the current feedback control loop at all times in the y-th characteristic interval, as well as the mean, range, and dispersion of the characteristic coefficients at all times, are calculated to form a comparative characteristic sequence of the voltage feedback control loop in the y-th characteristic interval at the current adjustment time.

[0056] Based on the above analysis, the characteristic value of the fluctuation impact of the voltage feedback control loop in the y-th characteristic interval at the current adjustment time is determined by the metric distance between the characteristic sequence and the comparison characteristic sequence of the voltage feedback control loop in the y-th characteristic interval at the current adjustment time, and the similarity between the output parameters of the voltage feedback control loop in the y-th characteristic interval at the current adjustment time and the output parameters of the current feedback control loop. Specifically, the characteristic value of the fluctuation impact of the voltage feedback control loop in the y-th characteristic interval at the current adjustment time is positively correlated with the metric distance and negatively correlated with the similarity. A larger metric distance indicates a more significant deviation between the output parameters within the corresponding characteristic interval, while a smaller similarity indicates a greater collaborative control deviation under the influence of dynamic fluctuations within the corresponding characteristic interval.

[0057] In this embodiment, the expression for the influence of the voltage feedback control loop's fluctuation on the y-th characteristic interval at the current adjustment time is:

[0058] In the formula, Let y be the characteristic value of the fluctuation effect of the voltage feedback control loop in the y-th characteristic interval at the current adjustment time. Let be the metric distance between the characteristic sequence of the y-th characteristic interval of the voltage feedback control loop at the current adjustment time and the comparison characteristic sequence. Let exp() be the similarity between the output parameters of the voltage feedback control loop and the output parameters of the current feedback control loop in the y-th characteristic interval at the current adjustment time, and let exp() be an exponential function with the natural constant as the base.

[0059] In this embodiment, the distance measurement is calculated using Euclidean distance. Implementers can choose other feasible distance measurement methods, such as DTW distance, Manhattan distance, etc. The similarity is calculated using Pearson correlation coefficient in this embodiment. Implementers can choose other feasible similarity calculation methods, such as cosine similarity, etc.

[0060] Accordingly, for the x-th characteristic interval of the current feedback control loop at the current adjustment time, the same acquisition method as that used for the y-th characteristic interval of the voltage feedback control loop at the current adjustment time can be adopted to obtain the x-th characteristic interval and the comparison characteristic sequence of the current feedback control loop at the current adjustment time. Furthermore, the same calculation method as that used for the fluctuation influence characteristic value of the voltage feedback control loop at the current adjustment time can be adopted to determine the fluctuation influence characteristic value of the current feedback control loop at the current adjustment time.

[0061] The larger the calculated characteristic value of the fluctuation impact, the more significant the stage characteristics of its dynamic fluctuation are based on the characteristic interval analysis of the instantaneous overshoot response of each feedback control loop.

[0062] Step S005: Integrate the fluctuation influence characteristic values ​​of all characteristic intervals of each feedback control loop at the current adjustment time with the characteristic coefficients to obtain the response coefficients of each feedback control loop at the current adjustment time, so as to adjust the proportional coefficient and integral coefficient when using the PI control algorithm to control each feedback control loop.

[0063] Furthermore, by combining the instantaneous overshoot characteristics of different feedback control loops, the characteristics of each output parameter affected by dynamic fluctuations in different characteristic ranges are precisely analyzed. Based on the analysis results, the overshoot response characteristics under the influence of dynamic fluctuations in different stages are comprehensively analyzed.

[0064] Specifically, for each feedback control loop, the mean of the absolute values ​​of the characteristic coefficients of the output parameter data within each defined characteristic interval is calculated, and the mean of these absolute values ​​is used as the response value to the impact of dynamic fluctuations in the parameters within each characteristic interval. Furthermore, considering the stage-specific characteristics of the output parameters being affected by dynamic fluctuations at different stages, the response coefficient of the overshoot effect of each feedback control loop at the current adjustment moment is calculated. Taking the voltage feedback control loop as an example, its calculation formula is as follows:

[0065] ;in, The response coefficient represents the overshoot effect of the voltage feedback control loop at the current adjustment moment. This represents the response value of the voltage feedback control loop to the dynamic fluctuations of parameters within the y-th characteristic interval at the current adjustment time. The value represents the characteristic value of the fluctuation influence of the voltage feedback control loop in the y-th characteristic interval at the current adjustment time. sof() represents the Softmax normalization function, which aims to accurately analyze the overshoot influence characteristics of each output parameter at the current adjustment time based on the fluctuation influence characteristic value of the output parameter under the influence of dynamic fluctuations at different stages as the dynamic response weight. The larger the calculated response coefficient, the more significant the stage overshoot influence characteristics of the corresponding feedback control loop output parameter under the influence of dynamic fluctuations, and the greater the possibility of deviation in its control response.

[0066] Using the same calculation method as for the response coefficient of the overshoot effect of the voltage feedback control loop at the current adjustment moment, the voltage feedback control loop is replaced with a current feedback control loop, and the response coefficient of the overshoot effect of the current feedback control loop at the current adjustment moment is calculated.

[0067] Based on the characteristics of overshoot deviation during the operation of a high-voltage DC / DC converter at the current adjustment moment, dynamic optimization and adjustment are performed on the voltage and current closed-loop processes of the high-voltage DC / DC converter, thereby reducing the impact of the dynamic fluctuation characteristics of load and input parameters on the dual closed-loop control of the converter.

[0068] Specifically, in this embodiment, the voltage loop and current loop of the high-voltage DC / DC converter are controlled using a PI (Proportional Integral) control method. The initial proportional and integral parameters of the current and voltage loops in the PI control process are determined using the attenuation curve method, a well-known existing technique, the specific process of which is not detailed here. If the response coefficient of the high-voltage DC / DC converter is significantly larger due to overshoot caused by dynamic fluctuations at the current adjustment moment, the proportional coefficient needs to be increased accordingly for the voltage loop to improve its response speed. Furthermore, the integral coefficient needs to be increased while maintaining the response speed. Therefore, the PI parameters of the actual control process are adjusted in stages based on the response coefficients of each feedback control loop at the current adjustment moment. Specifically:

[0069] The voltage loop adjustment process is as follows:

[0070] First, to balance the voltage loop's response speed and suppression capability to disturbances during the operation of the high-voltage DC / DC converter, and to avoid over-adjustment, the maximum values ​​of the proportional and integral parameters from historical adjustment times up to the current monitoring adjustment time are used as the adjustment threshold during the adjustment process. , .

[0071] Based on the determined response coefficients, the proportional and integral coefficients in the voltage loop are adjusted in stages. At the current adjustment moment, the adjustment relationship is as follows: , ,in, This is the proportional gain adjusted by the voltage loop at the current adjustment moment. This represents the initial value of the proportional coefficient for the PI control algorithm corresponding to the voltage loop. This represents the maximum proportional gain of the PI control algorithm during the historical adjustment period of the voltage loop. This represents the response coefficient of the voltage loop at the current adjustment moment; This represents the integral coefficient of the voltage loop after adjustment at the current adjustment moment. These are the initial values ​​of the integral coefficients for the PI control algorithm corresponding to the voltage loop. This represents the maximum integral coefficient of the PI control algorithm during the historical adjustment period of the voltage loop.

[0072] At the current adjustment moment, the output parameters of the high-voltage DC / DC converter are controlled by PI based on the proportional and integral parameters of the adjusted PI control algorithm.

[0073] The adjustment process for the current loop is as follows:

[0074] First, to reduce the impact of large current tracking errors or significant current overshoot during load abrupt changes on the current loop control; if the current tracking error is large or the current overshoot is significant during load abrupt changes (i.e., the calculated response coefficient is larger), the proportional coefficient of the current loop PI controller needs to be reduced to decrease the response sensitivity of the current loop and suppress overshoot. Simultaneously, the integral parameter needs to be increased to ensure that the current converges quickly to the reference value during dynamic processes. To avoid over-adjustment, this embodiment uses the maximum values ​​of the proportional and integral parameters of the PI control algorithm from historical adjustment times up to the current monitoring and adjustment time as the adjustment threshold during the adjustment process. , .

[0075] Based on the determined response coefficients, the proportional and integral coefficients in the current loop are adjusted in stages. At the current adjustment moment, the adjustment relationship is as follows: , ,in, This is the proportional gain adjusted by the current feedback control loop at the current adjustment moment. This represents the initial value of the proportional coefficient for the PI control algorithm corresponding to the current feedback control loop. This represents the maximum proportional gain of the PI control algorithm in the current feedback control loop during historical adjustment periods. Let be the response coefficient of the current feedback control loop at the current adjustment moment. This represents the integral coefficient of the current feedback control loop after adjustment at the current adjustment moment. These are the initial values ​​of the integral coefficients for the PI control algorithm corresponding to the current feedback control loop. This represents the maximum integral coefficient of the PI control algorithm during historical adjustment periods for the current feedback control loop. The flowchart for adjusting the proportional and integral coefficients of the PI control algorithm at the current adjustment period is shown below. Figure 2 As shown.

[0076] At the current adjustment moment, the output parameters of the high-voltage DC / DC converter are controlled by PI based on the proportional and integral parameters of the adjusted PI control algorithm. The voltage and current dual-loop control process of the high-voltage DC / DC converter based on a PI controller is a well-known existing technology, and will not be described in detail in this embodiment.

[0077] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, specific embodiments of this specification have been described above. Additionally, the processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some implementations, multitasking and parallel processing are possible or may be advantageous.

[0078] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0079] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them; modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions of some of the technical features, do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A dual closed-loop control method for a high-voltage DC / DC converter, characterized in that, The method includes the following steps: The output parameters of each feedback control loop of the high-voltage DC / DC converter are collected at each moment. Based on the difference between the output parameters at each moment and the rated output parameters, the characteristic coefficients of each feedback control loop at each moment are determined; the adjustment time is set at fixed time intervals. Analyze the abnormal conditions of the characteristic coefficients of each feedback control loop at all times between the current adjustment time and its adjacent adjustment times, divide the time period between the current adjustment time and its adjacent adjustment times, and determine the characteristic intervals of each feedback control loop at the current adjustment time. By comparing the numerical distribution differences between all output parameters of each feedback control loop in each characteristic interval at the current adjustment time and all output parameters of another feedback control loop in the same characteristic interval, the fluctuation impact characteristic value of each feedback control loop in each characteristic interval at the current adjustment time is determined. By integrating the fluctuation influence characteristic values ​​of all characteristic intervals of each feedback control loop at the current adjustment time with the characteristic coefficients, the response coefficient of each feedback control loop at the current adjustment time is obtained, so as to adjust the proportional coefficient and integral coefficient when using the PI control algorithm to control each feedback control loop; The feedback control loop includes a voltage feedback control loop and a current feedback control loop; The determination of the characteristic value of the fluctuation effect includes: For the y-th characteristic interval of the voltage feedback control loop at the current adjustment time, calculate the mean, range, and dispersion of the output parameters at all times, as well as the mean, range, and dispersion of the characteristic coefficients at all times, and arrange them in a fixed order to form the characteristic sequence of the y-th characteristic interval of the voltage feedback control loop at the current adjustment time. Correspondingly, the mean, range, and dispersion of the output parameters of the current feedback control loop at all times in the y-th characteristic interval are calculated, as well as the mean, range, and dispersion of the characteristic coefficients at all times, forming a comparative characteristic sequence of the voltage feedback control loop in the y-th characteristic interval at the current adjustment time. Based on the metric distance between the feature sequence and the comparison feature sequence of the voltage feedback control loop in the y-th feature interval at the current adjustment time, and the similarity between the output parameters of the voltage feedback control loop in the y-th feature interval at the current adjustment time and the output parameters of the current feedback control loop, the fluctuation influence characteristic value of the voltage feedback control loop in the y-th feature interval at the current adjustment time is determined. The fluctuation influence characteristic value of the voltage feedback control loop in the y-th characteristic interval at the current adjustment time is positively correlated with the metric distance and negatively correlated with the similarity.

2. The dual closed-loop control method for a high-voltage DC / DC converter as described in claim 1, characterized in that, Determining the characteristic coefficients of each feedback control loop at each time step includes: For each feedback control loop, the difference between the output parameter and the rated output parameter at each time step is calculated, and the ratio of the difference to the rated output parameter is used as the characteristic coefficient of each feedback control loop at each time step.

3. The dual closed-loop control method for a high-voltage DC / DC converter as described in claim 1, characterized in that, Determining the characteristic intervals of each feedback control loop at the current adjustment time includes: The time interval between the current adjustment time and its adjacent previous adjustment time is recorded as the adjustment period. The abrupt change points of the characteristic coefficients of each feedback control loop at all times within the adjustment period are detected. Based on all the abrupt change points of each feedback control loop within the adjustment period, the corresponding characteristic intervals of each feedback control loop are obtained.

4. The dual closed-loop control method for a high-voltage DC / DC converter as described in claim 3, characterized in that, Each characteristic interval corresponding to each feedback control loop is the time interval between each abrupt change point of each feedback control loop within the adjustment period and the current adjustment moment.

5. The dual closed-loop control method for a high-voltage DC / DC converter as described in claim 1, characterized in that, The process of obtaining the response coefficients of each feedback control loop at the current adjustment time includes: Calculate the average of the absolute values ​​of the characteristic coefficients of each feedback control loop at all times within each characteristic interval at the current adjustment time. Calculate the product of the normalized value of the fluctuation influence characteristic value of each feedback control loop at each characteristic interval at the current adjustment time and the average value. The response coefficient is the sum of the products of each feedback control loop at all characteristic intervals at the current adjustment time.

6. The dual closed-loop control method for a high-voltage DC / DC converter as described in claim 1, characterized in that, The adjustment employs a PI control algorithm to control the proportional and integral coefficients of each feedback control loop, including: For the voltage feedback control loop, the maximum value of the proportional coefficient and the maximum value of the integral coefficient of the PI control algorithm at each historical adjustment time are obtained respectively; the difference between the maximum value of the proportional coefficient and the initial value of the proportional coefficient is calculated and multiplied by the response coefficient of the voltage feedback control loop at the current adjustment time; the sum of the result of the multiplication and the initial value of the proportional coefficient is used as the adjusted proportional coefficient of the voltage feedback control loop at the current adjustment time. Accordingly, the integral coefficient of the voltage feedback control loop after adjustment at the current adjustment time is obtained by using the same calculation method as the proportional coefficient adjusted by the voltage feedback control loop at the current adjustment time. Based on the maximum proportional and integral coefficients of the PI control algorithm in the historical adjustment time of the current feedback control loop, and combined with the response coefficient of the current feedback control loop at the current adjustment time, the adjusted proportional and integral coefficients of the current feedback control loop at the current adjustment time are determined.

7. The dual closed-loop control method for a high-voltage DC / DC converter as described in claim 6, characterized in that, The proportional coefficient adjusted by the current feedback control loop at the current adjustment moment The expression is: In the formula, This represents the initial value of the proportional coefficient for the PI control algorithm corresponding to the current feedback control loop. This represents the maximum proportional gain of the PI control algorithm in the current feedback control loop during historical adjustment periods. This represents the response coefficient of the current feedback control loop at the current adjustment moment.

8. The dual closed-loop control method for a high-voltage DC / DC converter as described in claim 7, characterized in that, The integral coefficient of the current feedback control loop after adjustment at the current adjustment time The expression is: In the formula, These are the initial values ​​of the integral coefficients for the PI control algorithm corresponding to the current feedback control loop. This represents the maximum integral coefficient of the PI control algorithm in the current feedback control loop during historical adjustment times.

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