CN119298678A

CN119298678A - Slope compensation method and device of converter and converter

Info

Publication number: CN119298678A
Application number: CN202411815285.4A
Authority: CN
Inventors: 张豪; 王旭; 成楠
Original assignee: Suzhou Shidai Xin'an Energy Technology Co ltd
Current assignee: Suzhou Shidai Xin'an Energy Technology Co ltd
Priority date: 2024-12-11
Filing date: 2024-12-11
Publication date: 2025-01-10
Anticipated expiration: 2044-12-11
Also published as: CN119298678B

Abstract

The application provides a slope compensation method and device of a converter and the converter, and relates to the technical field of electronics; the method comprises the steps of obtaining an inductance current of a target inductance connected with an output end of a converter in an n-1 th period and a duty ratio of a target switching tube connected with an input end of the converter in the n-1 th period, determining a descending slope of the inductance current in the n-1 th period according to the inductance current and the duty ratio to serve as a slope compensation slope of the n-th period, predicting the duty ratio of the target switching tube in the n-th period according to the slope compensation slope of the n-th period, adjusting the slope compensation slope of the n-th period according to a difference value between the predicted duty ratio of the n-th period and the duty ratio of the n-1 th period, and performing slope compensation on the inductance current according to the slope compensation slope. According to the scheme, the slope compensation slope can be accurately calculated without adding an additional auxiliary sampling circuit, and the circuit cost of slope compensation is reduced.

Description

Slope compensation method and device for converter and converter

Technical Field

The present invention relates to the field of electronic technologies, and in particular, to a slope compensation method and apparatus for a converter, and a converter.

Background

With the development of new energy technology, the demand for power products with high power, small volume and wide range is increasing. Among them, in the development control of DC-DC converter products, the peak current control mode is widely used because of its advantages of fast response speed, simple control, and the like. But the peak current control mode may exhibit subharmonic oscillations at high duty cycles.

At present, an adaptive slope compensation method is provided for solving the problem that subharmonic oscillation occurs in a peak current control mode at a high duty ratio, and the slope compensation slope is adjusted according to real-time working conditions mainly through an additional inductance current slope or a duty ratio sampling circuit.

However, the current method requires an additional monitoring circuit, and the circuit cost is high.

Disclosure of Invention

The embodiment of the invention provides a slope compensation method and device of a converter and the converter, which can detect an accurate slope compensation slope without additionally adding a monitoring circuit and reduce circuit cost.

In a first aspect, an embodiment of the present invention provides a slope compensation method of an inverter, including:

Obtaining an inductance current of a target inductance connected with an output end of the converter in an n-1 th period and a duty ratio of a target switching tube connected with an input end of the converter in the n-1 th period, wherein n is a positive integer larger than 2;

Determining the descending slope of the inductive current in the n-1 th period according to the inductive current and the duty ratio, and taking the descending slope as the slope compensation slope of the n-1 th period;

Predicting the duty ratio of the target switching tube in the nth period according to the slope compensation slope of the nth period;

According to the difference value between the predicted duty ratio of the target switching tube in the nth period and the duty ratio of the n-1 th period, adjusting the slope compensation slope of the nth period;

And carrying out slope compensation on the inductive current according to the slope compensation slope.

In a second aspect, an embodiment of the present invention provides a slope compensation device of an inverter, including:

the data acquisition module is used for acquiring the inductance current of a target inductance connected with the output end of the converter in the n-1 th period and the duty ratio of a target switching tube connected with the input end of the converter in the n-1 th period, wherein n is a positive integer greater than 1;

The slope compensation slope initial value determining module is used for determining the falling slope of the inductive current in the (n-1) th period according to the inductive current and the duty ratio, and taking the falling slope as the slope compensation slope of the (n) th period;

The duty ratio prediction module is used for predicting the duty ratio of the target switching tube in the nth period according to the slope compensation slope of the nth period;

the slope determining module is used for adjusting the slope compensation slope of the nth period according to the difference value between the predicted duty ratio of the target switching tube in the nth period and the duty ratio of the (n-1) th period;

and the slope compensation module is used for carrying out slope compensation on the inductive current according to the slope compensation slope.

In a third aspect, embodiments of the present invention provide a converter for implementing a method as described above.

The slope compensation method and device for the converter and the converter can directly utilize the inductance current of the target inductance in the converter and the sampling value of the duty ratio of the target switching tube, can finish the calculation of the slope compensation slope, does not need to add an additional auxiliary sampling circuit to calculate the slope compensation slope, and reduces the circuit cost of the slope compensation of the converter.

Drawings

In order to more clearly illustrate the technical solution of the embodiments of the present invention, the drawings that are needed to be used in the embodiments of the present invention will be briefly described, and it is possible for a person skilled in the art to obtain other drawings according to these drawings without inventive effort.

FIG. 1 is a schematic diagram of a topology of a converter according to an embodiment of the present application;

fig. 2 is a schematic flow chart of a slope compensation method according to an embodiment of the present application;

FIG. 3 is a schematic waveform diagram of carrier, inductor current and duty cycle provided by an embodiment of the present application;

FIG. 4 is a flowchart illustrating a method for determining an initial value of a slope compensation slope according to an embodiment of the present application;

fig. 5 is a schematic flow chart of a duty ratio determining method according to an embodiment of the present application;

FIG. 6 is a flowchart of a method for determining a slope compensation slope under a dynamic condition according to an embodiment of the present application;

Fig. 7 is a schematic flow chart of a self-adaptive slope compensation control method according to an embodiment of the present application;

FIG. 8 is a real simulation waveform of a prior art fixed slope compensation and an adaptive slope compensation provided by an embodiment of the present application;

FIG. 9 is a schematic diagram of a slope compensation device according to an embodiment of the present application;

fig. 10 is a schematic diagram of a hardware structure of an electronic device according to an embodiment of the present application.

Detailed Description

Features and exemplary embodiments of various aspects of the present invention will be described in detail below, and in order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings and the detailed embodiments. It should be understood that the particular embodiments described herein are meant to be illustrative of the invention only and not limiting. It will be apparent to one skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the invention by showing examples of the invention.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising" does not exclude the presence of additional identical elements in a process, method, article, or apparatus that comprises an element.

With the development of new energy technology, the demand for power products with high power, small volume and wide range is increasing. Power products can be classified into three types of alternating current-direct current (AC-DC) converters, direct current-direct current (DC-DC) converters, and direct current-alternating current (DC-AC) converters according to input and output characteristics of the power products. Among them, in the development control of DC-DC converter products, the peak current control mode is widely used because of its advantages of fast response speed, simple control, and the like. However, the peak current control mode may exhibit subharmonic oscillations at high duty cycles. Although the problem can be solved by introducing slope compensation, the dynamic response capability of the control system can be affected by too large slope setting of the slope compensation, and the problems of magnetic element bias and the like caused by too slow oscillation convergence can be caused by too small slope setting of the slope compensation.

The current slope compensation method is mainly divided into three types, ①, namely fixed slope compensation, and the method can cause the problems of over compensation or under compensation under different load working conditions and dynamic switching load working conditions due to the fixed slope compensation. Overcompensation affects the dynamic response capability of the control system, while undercompensation requires more switching cycles to correct subharmonic oscillation, which may cause problems such as magnetic saturation of the transformer in practical applications. ② The method is divided into three sections according to the size of the duty ratio, and each section adopts different slope compensation slopes so as to reduce the negative influence of the fixed slope compensation slopes on different working conditions. But the segmented slope compensation still has the problems of overcompensation and undercompensation under certain working conditions. ③ The method can adaptively adjust the slope of the slope compensation according to the real-time working condition. The method (1) can infer the relationship between the input voltage, the output voltage and the falling slope of the inductance current according to a volt-second balance formula in a steady state. Based on the self-adaptive slope compensation slope is calculated according to the input voltage and the output voltage acquired in real time, so that the self-adaptive slope compensation slope is matched with the actual working condition as much as possible. However, the inductor current slope calculated from the volt-second balance at steady state is in error with the steady state slope of the actual circuit. And (2) adjusting the slope compensation slope according to the real-time working condition by using an additional inductance current slope or duty ratio sampling circuit. However, additional detection circuitry is required, adding to the control cost. And no matter in the mode (1) or the mode (2), the adaptive slope compensation does not carry out targeted optimization on the dynamic working condition.

In order to solve the above problems, the embodiment of the application provides an accurate and low-cost adaptive slope compensation control scheme based on a digital control technology without adding an additional detection circuit. Meanwhile, the scheme optimizes the dynamic working condition on the basis of the existing slope compensation, so that more accurate slope compensation can be provided in a steady state, and the slope of the slope compensation can be actively regulated in a dynamic state to avoid abrupt change of the duty ratio. In addition, aiming at the problem that the primary side of a hard switch full-bridge DC-DC converter controlled by peak current can cause saturation of a transformer magnetic core due to abnormal-size waveguide during dynamic driving, the scheme can actively adjust the slope compensation slope according to sampling data so as to avoid the occurrence of size waves.

The technical scheme of the application is described in detail through specific embodiments. It should be noted that the following embodiments may be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

In order to facilitate understanding of the present solution, first, a circuit structure of the converter provided by the embodiment of the present application is described. Fig. 1 is a schematic diagram of a topology of a converter, which may be referred to as a hard-switching full-bridge DC-DC converter, according to an embodiment of the present application. As shown in fig. 1, in order to coordinate with the calculation of the adaptive slope compensation slope, the inductor current of the target inductor L1 and the driving duty ratio of the target switching tube Q1 need to be acquired. The switching tubes Q1-Q4 are primary side switching tubes, the switching tube Q5 and the switching tube Q6 are secondary side rectifying tubes, and the switching tube Q7 and the switching tube Q8 are active absorption tubes of the secondary side rectifying switching tubes.

Fig. 2 is a schematic flow chart of a slope compensation method according to an embodiment of the present application, and the method may be specifically applied to the foregoing converter. As shown in fig. 2, the method specifically may include the following steps:

Step S210, obtaining the inductance current of a target inductance connected with the output end of the converter in the n-1 th period and the duty ratio of a target switching tube connected with the input end of the converter in the n-1 th period.

Wherein n is a positive integer greater than 1. The target inductor is the inductor L1 in fig. 1, and the target switching tube is the primary switching tube Q1 in fig. 1.

In this embodiment, the inductor current of the target inductor at the n-1 th cycle may be sampled by Analog-to-Digital Conversion (ADC) conversion. Fig. 3 is a schematic waveform diagram of carrier, inductor current and duty ratio according to an embodiment of the present application, where, as shown in fig. 3, when the carrier count value is zero and the preset period value, the inductor current may be sampled, so as to obtain three sampling points, where the three sampling points sample to obtain three inductor currents respectivelyInductor currentAnd inductor current). Also when the carrier count value is zero, the duty cycle of the last cycle may be captured, illustratively, using an enhanced capture accumulator peripheral (Enhanced Capture Accumulator Peripheral, ECAP)。

Among other things, ECAP function is a module for Digital Signal Processing (DSP) that is capable of capturing and recording certain characteristics of an input signal, such as frequency, period, or duty cycle.

Wherein, will beThe inductor current, referred to as the first half of the n-1 th cycle, willThe inductor current, referred to as the latter half of the n-1 th cycle, willThe inductor current, referred to as the first half of the n-th cycle, is:

= Formula (1)

In the present embodiment of the present invention, in the present embodiment,Is the valley of the inductor current, which corresponds to the sampling point where the carrier count value is equal to zero. The n-1 th period may be understood as the last period, and the corresponding n-th period may be understood as the current period.

The sampling point is adjustable, for example, the sampling speed and the chip computing speed in practical application can be reasonably adjusted.

For example, the preset period value referred to in the present embodiment may refer to a period value of the carrier. Referring to fig. 3, the value of the carrier is 0, and the value of the carrier is a preset period value.

Step S220, determining the falling slope of the inductive current of the first half period in the n-1 th period as the slope compensation slope of the first half period in the n-1 th period according to the inductive current and the duty ratio.

In this embodiment, the inductor current falling slope of the first half period in the n-1 th period may be calculated as the slope compensation slope of the first half period in the n-1 th period based on the n-1 th period and the sampling data of the n-th period. Wherein the sampled data includes at least the inductor current of the n-1 th period and the duty cycle of the n-1 th period mentioned above.

When calculating the decreasing slope of the inductance current in the n-1 th period, the peak current can be calculated first:

formula (2)

In the above-mentioned (2),A peak current representing the first half of the n-1 th cycle; The loop control quantity of the n-1 th period is the intermediate quantity of digital control and can be directly called; A slope compensation slope representing the first half period of the n-1 th period; is the duty cycle of the first half of the n-1 th period, which is obtained by sampling in the n-th period; Indicating the switching period (i.e., the preset period value). The loop control quantity is an intermediate quantity of closed loop control, does not need additional sampling, and can be directly used.

Further, after the peak current is calculated, the calculation of the slope compensation slope of the first half of the nth cycle may be specifically divided into the following two cases:

(1) In non-dynamic conditions, at this time AndThe same falling slope is used:

Formula (3-1)

(2) Under dynamic conditions, due to the fact thatWhen the inductance current falling gradient is equal to 0, the calculation formula of the inductance current falling gradient needs to be correspondingly adjusted:

formula (3-2)

Wherein, Formula (4)

In the above-mentioned method, the step of,Is the slope compensation slope of the first half period in the nth period; is the slope compensation slope of the latter half of the nth cycle; 、、 Representing the inductor current for the n-1 th cycle.

In this embodiment, the slope compensation slope of the nth period calculated by the above formulas (2) to (4) is based on the fact that the slope of the inductor current decrease in adjacent periods in the non-dynamic phase is approximately equal, and cannot be directly used as the slope compensation slope in the dynamic phase to perform the slope compensation.

Step S230, predicting the duty ratio of the first half period of the target switching tube in the nth period according to the slope compensation slope of the first half period in the nth period.

In this embodiment, since the rising slopes of the inductor currents of the adjacent two periods are approximately equal in the dynamic or non-dynamic phase. Therefore, the rising slope of the induction current in the n-1 th period can be calculated through the sampling data and the loop output, and then the duty ratio of the next period is predicted based on the rising slope of the induction current in the n-1 th period.

Step S240, adjusting the slope compensation slope of the nth period according to the difference value between the duty ratio of the first half period of the target switching tube in the nth period and the duty ratio of the first half period of the n-1 th period.

In this embodiment, the current non-dynamic or dynamic condition may be determined by comparing the difference between the duty cycle of the first half of the nth cycle and the duty cycle of the first half of the n-1 th cycle. Under different working conditions, the slope compensation slope is obtained in different ways.

For example, with continued reference to FIG. 3 above, when in the non-dynamic condition, the slope of the decrease in inductor current in the first half of the n-1 th period may be used directly as the slope of the slope compensation in the n-th period for slope compensation control. For example, when in the dynamic working condition, the slope compensation slope of the nth cycle may be determined based on the peak current of the first half cycle of the nth cycle, the falling slope and rising slope of the inductor current of the first half cycle of the n-1 th cycle, the duty cycle of the first half cycle of the nth cycle, and the preset cycle value.

In this embodiment, when the difference between the duty cycle of the current cycle and the duty cycle of the previous cycle exceeds a certain value, the dynamic phase is considered to be entered, otherwise the non-dynamic phase is considered to be entered. In practical engineering application, the judging condition of the dynamic working condition can be determined by loop output and the predicted duty ratio.

Step S250, performing slope compensation on the inductance current according to the slope compensation slope of the adjusted nth period.

In this embodiment, after determining the slope compensation slope, slope compensation may be adaptively performed according to the slope compensation slope, so as to implement duty cycle control and smooth state switching of the system, thereby improving dynamic response capability of the system and ensuring stability of the system.

In the embodiment of the application, the slope compensation slope of the inductance current is calculated by utilizing the inductance current, the duty cycle, the falling slope, the rising slope and the loop control quantity, the inductance current and the duty cycle are directly collected, other values are all control intermediate quantities, the inductance current needs to be sampled in normal peak current control, and meanwhile, the duty cycle can be obtained through an ECAP function of the DSP without an additional sampling circuit, so that the control cost of self-adaptive slope compensation is reduced to a certain extent.

How the slope compensation slope is obtained is described in detail below by some embodiments.

Fig. 4 is a flowchart of a method for determining an initial value of a slope compensation slope according to an embodiment of the present application, as shown in fig. 4, including the following steps:

Step S410, determining the peak current of the first half period of the n-1 th period of the target inductor.

Step S420, under the condition that the duty ratio of the first half period in the n-1 th period is larger than zero, determining the falling slope of the inductive current of the first half period in the n-1 th period as the slope compensation slope of the first half period in the n-1 th period according to the peak current, the inductive current of the second half period in the n-1 th period, the preset period value and the duty ratio of the first half period in the n-1 th period.

Step S430, under the condition that the duty ratio of the first half period in the n-1 th period is equal to zero, determining the falling slope of the inductive current of the first half period in the n-1 th period as the slope compensation slope of the first half period in the n-1 th period according to the inductive current of the second half period in the n-1 th period, the inductive current of the first half period in the n-1 th period and the preset period value.

Step S440, the falling slope of the inductance current of the first half period in the n-1 th period is used as the slope compensation slope of the first half period in the n-th period.

Step S450, using the slope compensation slope of the first half period in the nth period as the slope compensation slope of the second half period in the nth period.

Wherein, for step S410, the peak current may be determined by, for example, two ways:

in the slope compensation process, the peak current of the target inductor in the period can be determined by continuously collecting the change condition of the inductor current in one period in the mode (1).

The method (2) comprises determining the descending slope of the inductive current of the first half period of the n-2 th period according to the inductive current of the second half period of the n-2 th period, the peak current of the first half period of the n-2 th period, the preset period value and the duty ratio of the n-2 th period, using the descending slope of the inductive current of the first half period of the n-2 th period as the slope compensation slope of the first half period of the n-1 th period, and determining the peak current of the first half period of the n-1 th period based on the loop control quantity of the n-1 th period, the slope compensation slope of the first half period of the n-1 th period, the duty ratio of the first half period of the n-1 th period and the preset period value.

For the mode (2), for example, reference may be made specifically to the above formula (2), calculated by the above formula (2)As the peak current of the first half of the n-1 th cycle. The peak current is calculated by the formula (2), and an additional detection circuit is not needed, so that the control cost of the adaptive slope compensation is reduced to a certain extent.

For step S420, the falling slope of the inductor current in the first half of the n-1 th period can be calculated by the above formula (3-1).

Wherein, formula (3-1)Representing the switching period, i.e. the preset period value, whichRelated to the carrier period, by adjusting the carrier period, different settings can be correspondingly setAnd calculating to obtain the descending slope of the inductance current of the first half period in the n-1 th period under different carrier periods.

Exemplary, assume thatThe falling slope of the inductor current in the first half of the n-1 th period can be calculated by:

Exemplary, assume that The falling slope of the inductor current in the first half of the n-1 th period can be calculated by:

for step S430, the falling slope of the inductor current in the first half of the n-1 th period can be calculated by the above formula (3-2). Similarly, can correspondingly arrange different And calculating to obtain the descending slope of the inductance current of the first half period in the n-1 th period under different carrier periods.

For step S440 and step S450, calculated by the above formula (3-1) or formula (3-2)Thereafter, because of the non-dynamic condition,AndThe same slope compensation slope is adopted, so thatThereby obtaining the slope compensation slope of the first half period of the nth periodAnd the slope of the slope compensation in the latter half of the nth cycle。

In the embodiment of the application, when the difference between the predicted duty cycle of the nth cycle and the duty cycle of the (n-1) th cycle is smaller than the first threshold, the slope compensation slope of the nth cycle can be directly utilized to perform slope compensation, so that the slope compensation slope is calculated by using only the inductor current, the duty cycle, the falling slope and the loop control quantity. The whole calculation process only needs to collect the inductance current and the duty ratio as input, and other values are control intermediate quantities, so that an additional sampling circuit is not needed, and the control cost of the self-adaptive slope compensation is reduced to a certain extent.

Fig. 5 is a flow chart of a duty ratio determining method according to an embodiment of the present application, as shown in fig. 5, including the following steps:

And S510, under the condition that the duty ratio of the first half period in the n-1 th period is not equal to zero, determining the rising slope of the inductive current of the first half period in the n-1 th period according to the peak current of the first half period in the n-1 th period, the inductive current of the first half period in the n-1 th period, the duty ratio of the first half period in the n-1 th period and the preset period value.

In step S520, when the duty ratio of the first half period of the n-1 th period is equal to zero, the rising slope of the inductor current recorded before the n-1 th period when the duty ratio is non-zero is used as the rising slope of the inductor current of the n-1 th period.

Step S530, predicting the duty ratio of the first half period in the nth period according to the loop control quantity of the nth period, the inductance current of the first half period in the nth period, the rising slope of the inductance current of the first half period in the n-1 th period, the slope compensation slope of the first half period in the nth period and the preset period value, and taking the predicted value as the duty ratio of the first half period in the nth period.

In this embodiment, the calculation of the predicted duty cycle predicts the driving duty cycle of the next switching cycle according to the rule that the rising slopes of the inductor currents in adjacent control cycles are approximately equal, so as to distinguish the dynamic and non-dynamic working conditions. The prediction formula is as follows:

Formula (5)

In the above-mentioned method, the step of,The loop control amount for the nth cycle is represented,Representing the duty cycle of the first half of the predicted nth cycle,The rising slope of the inductor current in the first half of the n-1 th cycle is shown.

Wherein, the following formula can be derived from formula (5):

Formula (6)

In the present embodiment, inUnder the condition of different values, different calculation modes exist for the rising slope of the inductance current in the first half period of the n-1 th period.

For step S510, in the case where the duty cycle of the first half of the n-1 th period is not equal to zero, i.e.When not equal to 0, the rising slope of the inductor current in the first half of the n-1 th period can be calculated by the following formula:

Formula (7-1)

For step S520, in the case where the duty cycle of the first half of the n-1 th period is equal to zero, i.e.When=0, the rising slope of the inductor current in the first half of the n-1 th period can be calculated by the following formula:

(Equation 7-2)

In the above-mentioned method, the step of,Indicating the rising slope of the inductor current recorded before the n-1 th period when the duty cycle is non-zero.

For step S530, the rising slope of the inductor current in the first half of the n-1 th period is calculatedThen, the duty ratio of the first half period in the nth period can be calculated by the above formula (6)As the duty cycle of the nth cycle.

In the embodiment of the application, the current working condition can be judged as the dynamic working condition or the non-dynamic working condition in an auxiliary mode by predicting the duty ratio of the next period, so that the dynamic and non-dynamic self-adaptive slope compensation control can be conveniently and better carried out later, and the slope compensation control effect is improved.

After the duty ratio of the nth cycle is calculated, the duty ratio of the current cycle and the duty ratio of the last cycle can be compared to judge as a dynamic working condition or a non-dynamic working condition. In some embodiments, when the system is in the non-dynamic working condition, the adaptive slope compensation control may be performed directly using the slope compensation slope of the nth period calculated in the previous step S220.

For example, the first threshold may be configured first, then the duty cycle of the first half of the nth cycle is subtracted from the duty cycle of the first half of the n-1 th cycle to obtain a first difference, and the first difference is compared with the configured first threshold. And when the first difference value is smaller than the first threshold value, determining that the working condition is a non-dynamic working condition. In other embodiments, the duty cycle of the first half of the n-1 th cycle may be subtracted from the duty cycle of the first half of the n-th cycle to obtain a second difference, and the second difference may be compared with the first threshold. And when the second difference value is smaller than the first threshold value, determining that the working condition is a non-dynamic working condition.

Further, when the first difference is greater than the first threshold, the dynamic working condition is judged to be entered. Further, a second threshold (the second threshold being greater than the first threshold) may be configured. When the difference between the duty ratio of the first half period of the nth period and the duty ratio of the first half period of the n-1 th period is larger than the first threshold value and smaller than the second threshold value, the first and second threshold values can be adjusted by adjusting the first and second threshold valuesAndIs of a size such thatAndApproximately (even though the duty cycle of the first half of the nth cycle is close to the duty cycle of the second half of the nth cycle) to avoid the saturation problem of the transformer core due to the size waveguide. When the difference between the duty ratio of the first half period of the nth period and the duty ratio of the first half period of the n-1 th period is larger than the second threshold or smaller than the negative second threshold, the duty ratio of the first half period of the n-1 th period is increased or decreased by a fixed step length to be used as the expected duty ratio of the first half period of the nth period, and the adaptive slope compensation slope is calculated according to the differenceAndSo as to realize the smooth switching treatment of the duty ratio of the adjacent period under the dynamic working condition.

When the difference between the duty ratio of the first half period in the nth period and the duty ratio of the first half period in the n-1 th period is larger than a first threshold value and smaller than a second threshold value, the dynamic working condition is determined, and the slope compensation slope of the first half period and the second half period in the nth period needs to be adjusted, so that the duty ratio of the first half period in the nth period is consistent with the duty ratio of the first half period in the n-1 th period. And when the difference value is larger than the second threshold value, the dynamic working condition is also determined, and the purpose of the dynamic working condition is to realize the smooth switching treatment of the duty ratio under the dynamic working condition by regulating the slope compensation slopes of the first half period and the second half period in the nth period so as to limit the difference value within a reasonable range.

In the embodiment of the application, during non-dynamic working conditions (namely a steady state and a transition section), the descending slope of the inductance current in the first half period in the n-1 th period is obtained through calculation and is used as the slope compensation slope of the n-th period to carry out self-adaptive slope compensation control, so that more accurate slope compensation can be provided during the steady state, and the slope compensation control effect is further improved.

Fig. 6 is a flowchart of a method for determining a slope compensation slope under a dynamic working condition according to an embodiment of the present application, as shown in fig. 6, and specifically includes the following steps:

Step S610, under the condition that the difference value is larger than the first threshold value and smaller than the second threshold value, determining the inductance current of the second half period in the nth period according to the peak current of the first half period in the nth period, the slope compensation slope of the first half period in the n-1 th period, the duty ratio of the first half period in the nth period and the preset period value.

Step S620, determining a slope compensation slope of the latter half period in the nth period according to the inductance current of the latter half period in the nth period, the rising slope of the inductance current of the former half period in the (n-1) th period, the duty cycle of the former half period in the nth period, the loop control quantity of the nth period and the preset period value.

In this embodiment, for step S610, the peak current of the first half period in the nth period may be calculated by the following formula:

Formula (8)

In the above-mentioned method, the step of,The peak current representing the first half of the nth cycle,The loop control amount for the nth cycle is represented,Indicating the slope of the slope compensation of the first half of the nth cycle,Representing the duty cycle of the first half of the nth cycle,Is a switching period, i.e. a preset period value.

Wherein use is made ofThe inductor current representing the latter half of the nth cycle can be calculated by the following formula:

Formula (9)

In the above-mentioned method, the step of,Indicating the slope of the slope compensation of the first half of the n-1 th period.

For step S620, the following formula (10) is set:

Formula (10)

Then let the=The following formula (11) can be obtained:

Formula (11)

In the above-mentioned method, the step of,Representing the slope of the slope compensation of the latter half of the nth period,The rising slope of the inductor current is calculated for the first half period of the n-1 th period.

In the embodiment of the application, under the dynamic time working condition, aiming at the problem that the full-bridge DC-DC converter can cause the saturation of the magnetic core of the transformer due to the large and small wave guides in the transient state, the method can actively adjust the slope compensation according to real-time data so as to avoid the occurrence of large and small wave, prevent the condition of abrupt change of duty ratio, further improve the slope compensation control effect and improve the stability and dynamic response capability of the system.

In other embodiments, it is also possible that the difference is greater than the first threshold and greater than the second threshold, in particular, byRepresenting the second threshold, there may be two cases:

Case 1:

Case 2:

Wherein, for both case 1 and case 2, the previously calculated adjustments need to be readjusted And。

In some embodiments, for case 1, where the duty cycle of the first half of the nth cycle is greater than the sum of the duty cycle of the first half of the nth-1 cycles and the second threshold, the slope compensation slope may be determined by:

(1) Updating the slope compensation slope in the first half period of the nth period as the slope compensation slope update value of the first half period, namely after updating, according to the inductive current in the first half period of the nth period, the rising slope of the inductive current in the first half period of the nth-1 period, the duty cycle of the first half period of the nth-1 period, the preset increasing step length, the preset period value and the loop control quantity of the nth period 。

(2) According to the loop control quantity of the nth cycle, the inductance current of the first half cycle in the nth cycle, the rising slope of the inductance current of the first half cycle in the nth-1 cycle, a preset cycle value and a slope compensation slope updating value, determining the duty ratio of the first half cycle in the nth cycle after updating as a duty ratio updating value;

(3) Determining slope compensation slope of the latter half period in the nth period (i.e. updated) according to the inductance current of the latter half period in the nth period, the rising slope of the inductance current of the former half period in the (n-1) th period, the duty cycle update value, the loop control amount of the nth period and the preset period value )。

In this embodiment, the previously calculated is readjustedAndThe specific calculation formula of (2) is as follows:

formula (12-1)

Formula (6)

Formula (11)

In the above-mentioned method, the step of,The inductor current of the first half of the nth cycle may be represented,Indicating the rising slope of the inductor current in the first half of the n-1 th period,Representing the duty cycle of the first half of the n-1 th period, STEP1 represents the appropriate STEP-up size (i.e., the preset STEP-up size),Indicating a value of the preset period of time,Is the loop control amount for the nth cycle. Wherein due to the formula (11)The value of (2) is changed, so that the calculation is needed again and the changed value is needed(I.e., the duty cycle update value) is re-brought into the above formula (11) to obtain the latest. By controlling the slope of the slope compensation in the latter half of the nth periodTo makeAndApproximately, to avoid the saturation problem of the transformer core caused by the size waveguide. It should be noted that, in the embodiment of the present application, under the dynamic working condition,AndAre not identical. While in the non-dynamic operating mode,AndThe same slope of the ramp is used.

Further, in other embodiments, for case 2, in the case that the duty cycle of the first half period in the n-1 th period is greater than the sum of the duty cycle of the first half period in the n-th period and the second threshold value, the slope compensation slope update value needs to be determined by:

And updating the slope compensation slope of the first half period in the nth period as a slope compensation slope update value according to the inductance current of the first half period in the nth period, the rising slope of the inductance current of the first half period in the nth-1 period, the duty cycle of the first half period in the nth-1 period, the preset descending step length, the preset period value and the loop control quantity of the nth period.

In particular, the previously calculated is readjustedAndThe specific calculation formula of (2) is as follows:

formula (12-2)

Formula (6)

Formula (11)

In the above equation, STEP2 represents a suitable STEP-down STEP (i.e., a preset STEP-down STEP),Is the loop control amount for the nth cycle. Wherein due to the formula (11)The value of (2) is changed, so that the changed value needs to be changedIs carried back into the above formula (11) to obtain the latest。

Additionally, in other embodiments, dynamic conditions may also occurEqual to 0, at which pointThe value is assigned to be 0, as recalculated(I.e., the falling slope of the inductor current in the first half of the updated nth cycle) and then based onEqual to 0,Equal to 0, readjust the previously calculated。

In the embodiment of the application, the smooth switching of the duty ratio in the dynamic state is realized by optimizing the self-adaptive slope compensation slope under the dynamic working condition, the problem of the size wave driven by the primary side pair tube in the dynamic state is restrained, and the stability and the dynamic response capability of the system are further improved.

Fig. 7 is a schematic flow chart of a self-adaptive slope compensation control method according to an embodiment of the present application, as shown in fig. 7, including the following steps:

step S710, analog-to-digital conversion sampling.

Step S720, calculating the self-adaptive slope compensation slope.

Step S730, predicting the duty cycle.

Step 740, determining whether to enter a dynamic working condition.

Step S750, optimizing the slope of the slope compensation.

In this embodiment, for step S710, the inductor current of the current period and the driving duty ratio of the primary side switching tube Q1 of the previous period are collected for the calculation of the adaptive slope compensation. In practical application, the sampling point needs to be reasonably adjusted according to the practical sampling speed and the chip computing speed.

For step S720, the inductor current falling slope of the previous cycle is calculated as the slope compensation slope of the next cycle according to the correspondence between the duty cycle of the previous cycle and the inductor current falling slope. The specific calculation is shown in the formula (2) -formula (4).

The slope compensation slope of the next period calculated in the mode can be directly used as the slope compensation slope of the front half period and the rear half period of the period in the non-dynamic stage, but can not be directly used as the adaptive slope compensation slope of the dynamic stage.

For step S730, in order to better perform dynamic and non-dynamic adaptive slope compensation control, judgment and control are assisted by predicting the duty cycle of the next cycle. In the dynamic or non-dynamic phase, the rising slopes of the inductor currents of two adjacent periods are approximately equal. Therefore, based on the inductor current, the duty ratio, and the loop control amount obtained by sampling, the duty ratio of the next cycle can be predicted, see formula (5), formula (6), formula (7-1), and formula (7-2).

For step S740, according to the actual test result, when the difference between the duty ratio obtained by prediction and the duty ratio of the previous cycle exceeds a certain value, the dynamic phase is considered to be entered, otherwise, the non-dynamic phase is considered to be entered, and the slope compensation slope of the next cycle calculated in step 720 is directly used for control. In practical engineering application, the judging condition of the dynamic working condition can be determined by loop output and the predicted duty ratio.

For step S750, the smooth switching of the duty cycle during dynamic is achieved by optimizing the adaptive slope compensation slope under the dynamic working condition, and the problem of the magnitude of the primary side pair tube driving during dynamic is suppressed, see formula (8) -formula (11), formula (12-1) and formula (12-2).

Fig. 8 is an exemplary, actual simulation waveform of an existing fixed slope compensation and an adaptive slope compensation provided by an embodiment of the present application. As shown in fig. 8, the current source circuit comprises a carrier wave, a primary side drive 1, a primary side drive 2, a slope compensation value, a primary side current of a transformer, a secondary side inductance current and an output voltage. The primary side current waveform of the transformer is a waveform with an absolute value, and the secondary side inductance current is a waveform with proper scaling. The method of the present application represents a great advantage in both steady state and dynamic state.

In the embodiment of the application, an additional auxiliary sampling circuit is not needed, and the calculation of the self-adaptive slope gradient can be completed by only utilizing the sampling of the inductance current and the duty ratio. And the adaptive slope compensation is optimized for the dynamic working condition for the first time. By combining the duty ratio prediction method and the dynamic self-adaptive slope calculation method, the problems of smooth transition and drive suppression of the system can be realized in a dynamic working condition, so that the stability and dynamic response capability of the system are improved.

The following are examples of the apparatus of the present application that may be used to perform the method embodiments of the present application. For details not disclosed in the embodiments of the apparatus of the present application, please refer to the embodiments of the method of the present application.

Fig. 9 is a schematic structural diagram of a slope compensation device according to an embodiment of the present application, as shown in fig. 9, the slope compensation device 900 includes a data acquisition module 910, a slope compensation slope initial value determining module 920, a duty cycle predicting module 930, a slope determining module 940, and a slope compensation module 950.

The data acquisition module 910 is configured to acquire an inductance current of a target inductance connected to an output end of the converter in an n-1 th period and a duty cycle of a target switching tube connected to an input end of the converter in the n-1 th period, where n is a positive integer greater than 1.

The slope compensation slope initial value determining module 920 is configured to determine a falling slope of the inductor current in the n-1 th period according to the inductor current and the duty cycle, as a slope compensation slope in the n-th period.

The duty cycle prediction module 930 is configured to predict the duty cycle of the target switching tube in the nth period according to the slope compensation slope of the nth period.

The slope determining module 940 is configured to adjust a slope compensation slope of the nth cycle according to a difference between the predicted duty cycle of the target switching tube in the nth cycle and the duty cycle of the n-1 th cycle.

The slope compensation module 950 is configured to perform slope compensation on the inductor current according to a slope compensation slope.

In one example, the slope compensation slope initial value determination module is specifically configured to:

Determining the peak current of the target inductance in the first half period of the n-1 th period;

Under the condition that the duty ratio of the first half period in the n-1 th period is larger than zero, determining the descending slope of the inductive current of the first half period in the n-1 th period as the slope compensation slope of the first half period in the n-1 th period according to the peak current, the inductive current of the second half period in the n-1 th period, the preset period value and the duty ratio of the first half period in the n-1 th period;

under the condition that the duty ratio of the first half period in the n-1 th period is equal to zero, determining the descending slope of the inductive current of the first half period in the n-1 th period as the slope compensation slope of the first half period in the n-1 th period according to the inductive current of the second half period in the n-1 th period, the inductive current of the first half period in the n-1 th period and the preset period value;

The slope compensation slope of the first half period in the nth period is used as the slope compensation slope of the second half period in the nth period.

According to the inductance current of the latter half period in the n-2 th period, the peak current of the former half period in the n-2 th period, the preset period value and the duty ratio of the n-2 th period, determining the descending slope of the inductance current of the former half period in the n-2 th period as the slope compensation slope of the former half period in the n-1 th period;

The peak current of the first half period of the n-1 th period is determined based on the loop control amount of the n-1 th period, the slope compensation slope of the first half period of the n-1 th period, the duty cycle of the first half period of the n-1 th period, and the preset period value.

In one example, the duty cycle prediction module is specifically configured to:

under the condition that the duty ratio of the first half period in the n-1 th period is not equal to zero, determining the rising slope of the inductive current of the first half period in the n-1 th period according to the peak current of the first half period in the n-1 th period, the inductive current of the first half period in the n-1 th period, the duty ratio of the first half period in the n-1 th period and a preset period value;

When the duty ratio of the first half period in the n-1 th period is equal to zero, the rising slope of the inductor current recorded before the n-1 th period when the duty ratio is non-zero is used as the rising slope of the inductor current in the n-1 th period;

And determining the duty ratio of the first half period in the nth period according to the loop control quantity of the nth period, the inductance current of the first half period in the nth period, the rising slope of the inductance current of the first half period in the n-1 th period, the slope compensation slope of the first half period in the nth period and the preset period value.

In one example, the slope determination module is specifically configured to:

acquiring a difference value between a predicted duty ratio of the target switching tube in an nth period and a duty ratio of the target switching tube in an (n-1) th period;

And under the condition that the difference value is smaller than a first threshold value, taking the falling slope of the inductance current of the first half period in the n-1 th period as the slope compensation slope of the first half period and the second half period in the n-th period.

In one example, the slope determination module is specifically configured to:

Under the condition that the difference value is larger than a first threshold value and smaller than a second threshold value, determining the inductance current of the second half period in the nth period according to the peak current of the first half period in the nth period, the slope compensation slope of the first half period in the nth-1 period, the duty ratio of the first half period in the nth period and the preset period value;

And determining the slope compensation slope of the latter half period in the nth period according to the inductance current of the latter half period in the nth period, the rising slope of the inductance current of the former half period in the (n-1) th period, the duty cycle of the former half period in the nth period, the loop control quantity of the nth period and the preset period value.

In one example, the slope determination module is specifically configured to:

Updating the slope compensation slope of the first half period in the nth period as the slope compensation slope update value of the first half period according to the inductor current of the first half period in the nth period, the rising slope of the inductor current of the first half period in the nth-1 period, the duty ratio of the first half period in the nth-1 period, the preset increase step length, the preset period value and the loop control amount of the nth period when the duty ratio of the first half period in the nth period is greater than the sum of the duty ratio of the first half period in the nth-1 period and the second threshold;

According to the loop control quantity of the nth cycle, the inductance current of the first half cycle in the nth cycle, the rising slope of the inductance current of the first half cycle in the nth-1 cycle, a preset cycle value and the slope compensation slope updating value, determining the duty ratio of the first half cycle in the nth cycle after updating as a duty ratio updating value;

And determining the slope compensation slope of the latter half period in the nth period as the slope compensation slope of the latter half period according to the inductance current of the latter half period in the nth period, the rising slope of the inductance current of the former half period in the (n-1) th period, the duty ratio updating value, the loop control quantity of the nth period and the preset period value.

In one example, the slope determination module is specifically configured to update the slope compensation slope of the first half period in the nth period as the slope compensation slope update value of the first half period in the nth period based on the inductor current of the first half period in the nth period, the rising slope of the inductor current of the first half period in the nth-1 period, the duty ratio of the first half period in the nth-1 period, the preset falling step, the preset period value, and the loop control amount of the nth period when the duty ratio of the first half period in the nth period is smaller than the difference between the duty ratio of the first half period in the nth period and the second threshold.

In one example, the slope determination module is specifically configured to update the slope compensation slope of the first half of the nth cycle to zero as the slope compensation slope update value of the first half of the nth cycle when the predicted duty cycle of the first half of the nth cycle is equal to zero.

The device provided by the embodiment of the application can be used for executing the method in the embodiment shown above, and the implementation principle and technical effects are similar, and are not repeated here.

It should be noted that, it should be understood that the division of the modules of the above apparatus is merely a division of a logic function, and may be fully or partially integrated into a physical entity or may be physically separated. The modules can be realized in the form of software which is called by the processing element, in the form of hardware, in the form of software which is called by the processing element, and in the form of hardware. For example, the data acquisition module may be a processing element that is set up separately, may be implemented in a chip of the above apparatus, or may be stored in a memory of the above apparatus in the form of program codes, and the functions of the data acquisition module may be called and executed by a processing element of the above apparatus. The implementation of the other modules is similar. In addition, all or part of the modules can be integrated together or can be independently implemented. The processing element here may be an integrated circuit with signal processing capabilities. In implementation, each step of the above method or each module above may be implemented by an integrated logic circuit of hardware in a processor element or an instruction in a software form.

Fig. 10 is a schematic diagram of a hardware structure of an electronic device according to an embodiment of the present application. The electronic device 1000 may include a processor 1001 and a memory 1002 storing computer program instructions.

In particular, the processor 1001 may include a central processing unit (Central Processing Unit, CPU), or an Application SPECIFIC INTEGRATED Circuit (ASIC), or may be configured as one or more integrated circuits that implement embodiments of the present invention.

Memory 1002 may include mass storage for data or instructions. By way of example, and not limitation, memory 1002 may include a hard disk drive (HARD DISK DRIVE, HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or universal serial bus (Universal Serial Bus, USB) drive, or a combination of two or more of the foregoing. In one example, the memory 1002 may include removable or non-removable (or fixed) media, or the memory 1002 is a non-volatile solid state memory. Memory 1002 may be internal or external to the integrated gateway disaster recovery device.

In one example, the Memory 1002 may be a Read Only Memory (ROM). In one example, the ROM may be mask-programmed ROM, programmable ROM (PROM), erasable PROM (EPROM), electrically Erasable PROM (EEPROM), electrically rewritable ROM (EAROM), or flash memory, or a combination of two or more of these.

Memory 1002 may include Read Only Memory (ROM), random Access Memory (RAM), magnetic disk storage media devices, optical storage media devices, flash memory devices, electrical, optical, or other physical/tangible memory storage devices. Thus, in general, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software comprising computer-executable instructions and when the software is executed (e.g., by one or more processors) it is operable to perform the operations described with reference to methods in accordance with aspects of the present disclosure.

The processor 1001 implements the method in the above-described embodiment by reading and executing computer program instructions stored in the memory 1002.

In one example, the electronic device may also include a communication interface 1003 and a bus 1004. As shown in fig. 10, the processor 1001, the memory 1002, and the communication interface 1003 are connected to each other by a bus 1004, and communicate with each other.

The communication interface 1003 is mainly used for implementing communication among the modules, devices, units and/or apparatuses in the embodiment of the invention.

Bus 1004 includes hardware, software, or both that couple the components of the online data flow billing device to each other. By way of example, and not limitation, the buses may include an accelerated graphics Port (ACCELERATED GRAPHICS Port, AGP) or other graphics Bus, an enhanced industry Standard architecture (Extended Industry Standard Architecture, EISA) Bus, a Front Side Bus (FSB), a HyperTransport (HT) interconnect, an industry Standard architecture (Industry Standard Architecture, ISA) Bus, an Infiniband interconnect, a Low Pin Count (LPC) Bus, a memory Bus, a Micro Channel Architecture (MCA) Bus, a Peripheral Component Interconnect (PCI) Bus, a PCI-Express (PCI-X) Bus, a Serial Advanced Technology Attachment (SATA) Bus, a video electronics standards Association local (VLB) Bus, or other suitable Bus, or a combination of two or more of these. Bus 1004 may include one or more buses, where appropriate. Although embodiments of the invention have been described and illustrated with respect to a particular bus, the invention contemplates any suitable bus or interconnect.

In addition, in conjunction with the method in the above embodiments, embodiments of the present invention may be implemented by providing a computer storage medium. The computer storage medium having stored thereon computer program instructions which when executed by a processor implement a method according to any of the above embodiments.

The embodiments of the present application also provide a computer program product comprising a computer program which, when executed, performs any of the methods of the embodiments described above.

The embodiment of the application also provides a converter, which can be referred to as a hard-switching full-bridge DC-DC converter. The transformer is used for realizing the method.

It should be understood that the invention is not limited to the particular arrangements and instrumentality described above and shown in the drawings. For the sake of brevity, a detailed description of known methods is omitted here. In the above embodiments, several specific steps are described and shown as examples. The method processes of the present invention are not limited to the specific steps described and shown, but various changes, modifications and additions, or the order between steps may be made by those skilled in the art after appreciating the spirit of the present invention.

The functional blocks shown in the above block diagrams may be implemented in hardware, software, firmware, or a combination thereof. When implemented in hardware, it may be, for example, an electronic Circuit, application SPECIFIC INTEGRATED Circuit (ASIC), appropriate firmware, plug-in, function card, or the like. When implemented in software, the elements of the invention are the programs or code segments used to perform the required tasks. The program or code segments may be stored in a machine readable medium or transmitted over transmission media or communication links by a data signal carried in a carrier wave. A "machine-readable medium" may include any medium that can store or transfer information. Examples of machine-readable media include electronic circuitry, semiconductor Memory devices, read-Only Memory (ROM), flash Memory, erasable Read-Only Memory (Erasable Read Only Memory, EROM), floppy disks, compact discs (Compact Disc Read-Only Memory, CD-ROM), optical discs, hard disks, fiber optic media, radio Frequency (RF) links, and so forth. The code segments may be downloaded via computer networks such as the internet, intranets, etc.

It should also be noted that the exemplary embodiments mentioned in this disclosure describe some methods or systems based on a series of steps or devices. The present invention is not limited to the order of the above-described steps, that is, the steps may be performed in the order mentioned in the embodiments, or may be performed in a different order from the order in the embodiments, or several steps may be performed simultaneously.

Aspects of the present disclosure are described above with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the disclosure. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions/acts specified in the flowchart and/or block diagram block or blocks. Such a processor may be, but is not limited to being, a general purpose processor, a special purpose processor, an application specific processor, or a field programmable logic circuit. It will also be understood that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware which performs the specified functions or acts, or combinations of special purpose hardware and computer instructions.

In the foregoing, only the specific embodiments of the present invention are described, and it will be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working processes of the systems, modules and units described above may refer to the corresponding processes in the foregoing method embodiments, which are not repeated herein. It should be understood that the scope of the present invention is not limited thereto, and any equivalent modifications or substitutions can be easily made by those skilled in the art within the technical scope of the present invention, and they should be included in the scope of the present invention.

Claims

1. A method of slope compensation for a converter, comprising:

2. The method of claim 1, wherein determining the falling slope of the inductor current for the n-1 th period as the slope of the slope compensation for the n-th period based on the inductor current and the duty cycle comprises:

Under the condition that the duty ratio of the first half period in the n-1 th period is larger than zero, determining the peak current of the target inductor in the first half period in the n-1 th period;

According to the peak current, the inductance current of the latter half period in the n-1 th period, the preset period value and the duty ratio of the former half period in the n-1 th period, determining the descending slope of the inductance current of the former half period in the n-1 th period as the slope compensation slope of the former half period in the n-1 th period;

3. The method of claim 2, wherein said determining the peak current of the first half of the n-1 th cycle of the target inductance comprises:

According to the inductance current of the latter half period in the n-2 th period, the peak current of the former half period in the n-2 th period, the preset period value and the duty ratio of the former half period in the n-2 th period, determining the descending slope of the inductance current of the former half period in the n-2 th period as the slope compensation slope of the former half period in the n-1 th period;

4. The method of claim 1, wherein predicting the duty cycle of the target switching tube in the first half of the nth cycle based on the slope of the slope compensation of the nth cycle comprises:

When the duty ratio of the first half period in the n-1 th period is equal to zero, the rising slope of the inductor current recorded before the n-1 th period when the duty ratio is non-zero is used as the rising slope of the inductor current in the first half period in the n-1 th period;

5. The method of claim 1, wherein said adjusting the slope of the slope compensation of the nth cycle comprises:

6. The method of claim 1, wherein said adjusting the slope of the slope compensation of the nth cycle comprises:

And adjusting the slope compensation slope of the latter half period in the nth period according to the inductance current of the latter half period in the nth period, the rising slope of the inductance current of the former half period in the (n-1) th period, the duty cycle of the former half period in the nth period, the loop control quantity of the nth period and the preset period value.

7. The method of claim 1, wherein said adjusting the slope of the slope compensation of the nth cycle comprises:

8. The method of claim 7, wherein updating the slope compensation slope of the first half of the nth cycle as the slope compensation slope update value of the first half of the nth cycle comprises:

And updating the slope compensation slope of the first half period in the nth period as the slope compensation slope update value of the first half period according to the inductor current of the first half period in the nth period, the rising slope of the inductor current of the first half period in the nth-1 period, the duty cycle of the first half period in the nth-1 period, the preset falling step length, the preset period value and the loop control amount of the nth period when the duty cycle of the first half period in the nth period is smaller than the difference between the duty cycle of the first half period in the nth-1 period and the second threshold.

9. The method of claim 7, wherein updating the slope compensation slope of the first half of the nth cycle as the slope compensation slope update value of the first half of the nth cycle comprises:

And updating the slope compensation slope of the first half period in the nth period to be zero when the predicted duty ratio of the first half period in the nth period is equal to zero, and taking the slope compensation slope of the first half period as the slope compensation slope updating value of the first half period.

10. A slope compensation device for a converter, comprising:

11. A transducer for implementing the method of any one of claims 1-9.