Wide-input Buck-Boost chopper control circuit and control method

Abstract

The present invention provides a wide-input Buck-Boost chopper control circuit and control method, the control circuit and control method comprising: a Buck-Boost circuit for stepping down or stepping up an input voltage; a Buck nonlinear dynamic controller for performing nonlinear dynamic calculations according to an input voltage, a reference voltage and an output voltage, and outputting a control signal of a Buck switch; a Boost voltage outer loop PID control circuit for performing PID calculations on an output voltage and a reference voltage to obtain a reference current; and a Boost current inner loop PID control circuit for performing PID calculations on a reference current and an input current, and outputting a control signal of a Boost switch. The present invention realizes high-precision output of a stable voltage in a wide input voltage range and a large power range.

Description

Technical Field

[0001] The present invention relates to the technical field of circuit control, and in particular to a wide-input Buck-Boost chopper control circuit and a control method. Background Art

[0002] Since the output power of new energy is unstable, a DC / DC converter with a wide input range is needed to improve the output characteristics. With the increasing level of aircraft informatization, the demand for various types of high-reliability and small-volume DC / DC converters is becoming increasingly urgent.

[0003] In high-end industrial electronic equipment such as cloud servers and communications, the power supply platform is built on a distributed power system structure. This structure requires an isolated DC / DC converter to convert the input voltage with a wide range of changes into a stable DC voltage that can be directly used by the equipment. In addition, in order to prevent the loss of important data, an uninterrupted power supply is generally used. Many systems need to be equipped with large-capacity batteries. According to the charging and discharging characteristics of the battery, the DC / DC converter between the battery and the input bus also needs to be able to adapt to a wide input voltage range.

[0004] As the degree of automation in underground coal mines increases, various monitoring and communication equipment use a power supply voltage of 1100V. Some coal mines require that the mine power supply can be directly connected to the 1100V power supply system, and the demand for wide-input DC / DC converters is also increasing.

[0005] LLC (Resonant Converters) resonant converter is an important research direction of wide input DC (Direct Current) / DC converter. LLC resonant converter has high efficiency, low electromagnetic interference, and can achieve zero voltage switch (Zero Voltage Switch, ZVS) of the primary switch tube and zero current switch (Zero Current Switch, ZCS) of the secondary rectifier diode, but it cannot be applied to occasions with a wide input voltage range. Therefore, in recent years, the research on the adaptability of LLC resonant converter to wide range operation has gradually increased. The main conversion methods include half-bridge three-level ZVS PWM DC / DC converter, three-level LLC series resonant DC / DC converter and composite full-bridge three-level LLC resonant converter, but they use many devices and the structure and control are relatively complex.

[0006] In order to simplify the structure and meet the development trend of wide input and high power density of portable power supply systems, many scholars have conducted research on Buck-Boost converters with wide input voltage characteristics. Some scholars have proposed a Buck-Boost converter with a wide input voltage range and the same polarity of input and output, and introduced a storage capacitor C to widen the input voltage range. Two storage inductors provide energy for the load; other scholars have proposed a high-efficiency Buck-Boost converter with a wide input voltage range suitable for electric vehicle power supply systems, and proposed a three-mode control strategy to achieve smooth conversion in the three modes of boost, buck, and buck-boost. However, the input voltage range of these studies is still not wide enough and the power is not large. Summary of the invention

[0007] The present invention provides a wide-input Buck-Boost chopper control circuit and a control method, which are used to solve the defects of the Buck-Boost converter in the prior art that the input voltage range is narrow and the power is not large, and to achieve high-precision output of stable voltage under the conditions of a wider input voltage range and a larger power range.

[0008] The present invention provides a wide-input Buck-Boost chopper control circuit, comprising:

[0009] Buck-Boost circuit, used to step down or boost the input voltage;

[0010] A Buck nonlinear dynamic controller, the input end of which is electrically connected to the output end of the Buck-Boost circuit, and the output end of which is electrically connected to the input end of the Buck-Boost circuit;

[0011] The Buck nonlinear dynamic controller is used to perform nonlinear dynamic calculation according to the input voltage, the reference voltage and the output voltage of the Buck-Boost circuit, and output a control signal of the Buck switch;

[0012] A Boost voltage outer loop PID control circuit, the input end of which is electrically connected to the output end of the Buck-Boost circuit, and is used to perform PID operation on the output voltage and the reference voltage to obtain a reference current;

[0013] The Boost current inner loop PID control circuit has an input end electrically connected to the output end of the Boost voltage outer loop PID control circuit, and an output end electrically connected to the Buck-Boost circuit, and is used to perform PID calculation on the reference current and the input current, and output a control signal of the Boost switch.

[0014] According to a wide input Buck-Boost chopper control circuit provided by the present invention, the Buck nonlinear dynamic controller comprises:

[0015] A limiting circuit, used for limiting the deviation between the reference voltage and the output voltage;

[0016] A multiplication calculator, whose input end is electrically connected to the output end of the limiting circuit, and is used to multiply the limited deviation and the input voltage;

[0017] An integral calculator, whose input end is electrically connected to the output end of the multiplication calculator, and whose output end is electrically connected to the input end of the Buck-Boost circuit, is used to integrate the product between the limited deviation and the input voltage after multiplying it by a preset constant.

[0018] According to a wide-input Buck-Boost chopper control circuit provided by the present invention, the limiting circuit limits the deviation between the reference voltage and the output voltage by using the following formula:

[0019]

[0020] Wherein, e is the deviation between the reference voltage and the output voltage, is the deviation after limitation, e max Determined by the range of e and the adjustment speed of e.

[0021] According to a wide-input Buck-Boost chopper control circuit provided by the present invention, the output of the integral calculator is calculated by the following formula:

[0022]

[0023] Among them, u buck is the output of the integral calculator, k non is the preset constant, V IN is the input voltage, is the deviation after restriction.

[0024] A wide input Buck-Boost chopper control circuit provided by the present invention also includes an input current sampling and compensation circuit, and a resistor;

[0025] The input end of the resistor is electrically connected to the input voltage, and the output end is electrically connected to the input end of the Buck-Boost circuit;

[0026] The input end of the input current sampling and compensation circuit is electrically connected to the input end of the resistor and connected to the output end of the resistor;

[0027] The output end of the input current sampling and compensation circuit is electrically connected to the input end of the Boost current inner loop PID control circuit;

[0028] The input current sampling and compensation circuit is used for sampling and compensating the input current.

[0029] According to a wide-input Buck-Boost chopper control circuit provided by the present invention, the Boost voltage outer loop PID control circuit is used to calculate the deviation between the reference voltage and the output voltage, and output a reference current;

[0030] The Boost current inner loop PID control circuit is used to calculate the deviation between the reference current and the input current output by the input current sampling and compensation circuit, and output a control signal of the Boost switch.

[0031] A wide input Buck-Boost chopper control circuit provided by the present invention further includes:

[0032] An input voltage sampling and compensation circuit, the input end of which is electrically connected to the input voltage, and the output end of which is electrically connected to the input end of the Buck nonlinear dynamic controller and the input end of the resistor, for sampling and compensating the input voltage;

[0033] An output voltage sampling and compensation circuit, whose input end is electrically connected to the output voltage, and whose output end is electrically connected to the input end of the Buck nonlinear dynamic controller and the input end of the Boost voltage outer loop PID control circuit, is used for sampling and compensating the output voltage.

[0034] A wide input Buck-Boost chopper control circuit according to the present invention also includes PWM and drive;

[0035] The input end of the PWM is electrically connected to the output end of the Buck nonlinear dynamic controller and the output end of the Boost current inner loop PID control circuit;

[0036] The output terminal of the PWM is electrically connected to the input terminal of the drive;

[0037] The output end of the driver is electrically connected to the input end of the Buck-Boost circuit.

[0038] According to a wide-input Buck-Boost chopper control circuit provided by the present invention, the Buck-Boost circuit is a two-tube or four-tube structure.

[0039] The wide-input Buck-Boost chopper control circuit and control method provided by the present invention use a Buck nonlinear dynamic controller in the Buck-Boost chopper control circuit to perform nonlinear dynamic calculation on the input voltage, the reference voltage and the output voltage, so as to obtain a control signal of the Buck switch for controlling the output voltage, thereby utilizing the simplest Buck-Boost topology structure to output a stable voltage with high precision in a wide input voltage range and a large power variation range. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 It is a structural schematic diagram of a wide-input Buck-Boost chopper control circuit provided by the present invention;

[0042] Figure 2 It is a structural schematic diagram of a Buck nonlinear dynamic controller in a wide-input Buck-Boost chopper control circuit provided by the present invention;

[0043] Figure 3 It is a schematic diagram of a four-tube topology structure of a Buck-Boost circuit in a wide-input Buck-Boost chopper control circuit provided by the present invention;

[0044] Figure 4 It is a curve diagram of the output voltage of the circuit when the input voltage is 380V in the wide input Buck-Boost chopper control circuit provided by the present invention;

[0045] Figure 5 This is one of the curve diagrams of the output voltage of the circuit when the input voltage is 700V in the wide input Buck-Boost chopper control circuit provided by the present invention;

[0046] Figure 6 It is a curve diagram of the output voltage of the circuit when the input voltage is 1120V in the wide input Buck-Boost chopper control circuit provided by the present invention;

[0047] Figure 7 This is the second curve diagram of the output voltage of the circuit when the input voltage is 700V in the wide input Buck-Boost chopper control circuit provided by the present invention;

[0048] Figure 8 It is a flow chart of the wide input Buck-Boost chopping control method provided by the present invention. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] Combine the following Figure 1 A wide input Buck-Boost chopper control circuit of the present invention is described, comprising:

[0051] Buck-Boost circuit is used to boost the input voltage V IN To lower or raise the blood pressure;

[0052] A Buck nonlinear dynamic controller, the input end of which is electrically connected to the output end of the Buck-Boost circuit, and the output end of which is electrically connected to the input end of the Buck-Boost circuit;

[0053] The Buck nonlinear dynamic controller is used to adjust the input voltage V IN , reference voltage V REF and the output voltage V of the Buck-Boost circuit OUT Perform nonlinear dynamic calculations and output Buck switch control signals;

[0054] The traditional Buck control method is the PID (Proportion, Integral and Derivative) control method, which is difficult to meet the high-precision Buck-Boost control problem under wide input and large power variation range. This embodiment proposes to use a Buck nonlinear dynamic controller for control.

[0055] The input of the Buck nonlinear dynamic controller consists of a sampled wide input voltage V IN 、The output voltage V of the Buck-Boost circuit OUT and reference voltage V REF , by performing nonlinear dynamic calculation on the input data, the control signal of the Buck switch is generated, providing a reference for the subsequent Buck-Boost circuit.

[0056] A Boost voltage outer loop PID control circuit, the input end of which is electrically connected to the output end of the Buck-Boost circuit, and is used to perform PID operation on the output voltage and the reference voltage to obtain a reference current;

[0057] The input of the Boost voltage outer loop PID control circuit includes the output voltage V of the Buck-Boost circuit OUT and reference voltage V REF The output of this input after PID operation is used as the input of the Boost current inner loop PID control circuit.

[0058] The Boost current inner loop PID control circuit has an input end electrically connected to the output end of the Boost voltage outer loop PID control circuit, and an output end electrically connected to the Buck-Boost circuit, and is used to perform PID calculation on the reference current and the input current, and output a control signal of the Boost switch.

[0059] The output of the boost voltage outer loop PID control circuit is calculated by the boost current inner loop PID control circuit to obtain a control signal of the boost switch, which is used to control the output voltage to track the reference voltage.

[0060] The Buck-Boost circuit adjusts the input voltage V according to the control signal of the Buck switch and the control signal of the Boost switch. IN Step down or step up the voltage.

[0061] This embodiment uses a Buck nonlinear dynamic controller in a Buck-Boost chopper control circuit to perform nonlinear dynamic calculations on the input voltage, the reference voltage, and the output voltage to obtain a control signal of a Buck switch that controls the output voltage. This uses the simplest Buck-Boost topology to output a stable voltage with high precision over a wide input voltage range and a large power variation range, thus meeting the application requirements of DC / DC choppers in many fields such as aerospace, new energy applications, communications, coal, and automation.

[0062] Based on the above embodiments, Figure 2 As shown, the Buck nonlinear dynamic controller in this embodiment includes:

[0063] A limiting circuit, used for limiting the deviation between the reference voltage and the output voltage;

[0064] Set the reference voltage V REF With V OUT The deviation between the output voltages is e = V REF -V OUT The amplitude of the output voltage deviation is limited by the limiting circuit to obtain the variable Make sure that the deviation used for adjustment is not too large or too small.

[0065] A multiplication calculator, whose input end is electrically connected to the output end of the limiting circuit, and is used to multiply the limited deviation and the input voltage;

[0066] Multiplication calculator is used to calculate With input voltage V IN The product between .

[0067] An integral calculator, whose input end is electrically connected to the output end of the multiplication calculator, and whose output end is electrically connected to the input end of the Buck-Boost circuit, is used to integrate the product between the limited deviation and the input voltage and multiply it by a preset constant to achieve the purpose of nonlinear regulation.

[0068] Optionally, the output u of the Buck nonlinear dynamic controller buck After PWM conversion and driving, the control signal of the Buck switch is obtained. Among them, the PWM conversion can be bipolar triangle wave modulation, and the driving can adopt a general driving method.

[0069] On the basis of the above embodiment, the amplitude limiting circuit in this embodiment limits the deviation between the reference voltage and the output voltage by using the following formula:

[0070]

[0071] Wherein, e is the deviation between the reference voltage and the output voltage, is the deviation after limitation, e max It is a constant determined by the range of e and the adjustment speed of e.

[0072] Based on the above embodiment, the output of the integral calculator in this embodiment is calculated by the following formula:

[0073]

[0074] Among them, u buck is the output of the integral calculator and also the output of the Buck nonlinear dynamic controller; k non is the preset constant, which determines the speed of adjustment, V IN is the input voltage, is the deviation after restriction.

[0075] The above equation is a nonlinear dynamic equation, V IN and All are variables. IN and The introduction of ensures that the output voltage maintains high accuracy when the input and power vary over a wide range.

[0076] Based on the above embodiments, Figure 1 As shown, this embodiment also includes an input current sampling and compensation circuit, and a resistor R1;

[0077] The input end of the resistor is electrically connected to the input voltage, and the output end is electrically connected to the input end of the Buck-Boost circuit;

[0078] The input end of the input current sampling and compensation circuit is electrically connected to the input end of the resistor and connected to the output end of the resistor;

[0079] The output end of the input current sampling and compensation circuit is electrically connected to the input end of the Boost current inner loop PID control circuit;

[0080] The input current sampling and compensation circuit is used to IN Sampling and compensation are performed. The role of compensation is to provide more adjustment margin for the system.

[0081] On the basis of the above embodiment, the Boost voltage outer loop PID control circuit in this embodiment is used to calculate the deviation between the reference voltage and the output voltage, and output a reference current;

[0082] Calculate the given reference voltage V REF The instantaneous output voltage V OUT The deviation between e = V REF -V OUT , take e as the input of the PID control law, and calculate the output of the PID control law according to the following formula.

[0083]

[0084] Among them, k VP is the outer ring proportional coefficient, k VI is the outer loop integral coefficient, k VD is the outer loop differential coefficient, and the calculated reference signal current I REF As the input of the current inner loop PID control link.

[0085] The Boost current inner loop PID control circuit is used to calculate the deviation between the reference current and the input current output by the input current sampling and compensation circuit, and output a control signal of the Boost switch.

[0086] Calculate the given reference signal current I REF With the instantaneous input current I IN The deviation between I =I REF -I IN . IAs the input of the PID control law, the output of the PID control law is calculated according to the following formula.

[0087]

[0088] Among them, k IP is the inner ring proportional coefficient, k II is the inner loop integral coefficient, k ID is the inner loop differential coefficient, the calculated signal u boost As the input of PWM conversion, such as bipolar triangle wave modulation link.

[0089] Based on the above embodiment, this embodiment also includes:

[0090] An input voltage sampling and compensation circuit, the input end of which is electrically connected to the input voltage, and the output end of which is electrically connected to the input end of the Buck nonlinear dynamic controller and the input end of the resistor, for sampling and compensating the input voltage;

[0091] Before the Boost current inner loop PID calculation, the system needs to sample the instantaneous input current I IN , and compensate for it. The role of compensation is to provide more adjustment margin for the system.

[0092] An output voltage sampling and compensation circuit, whose input end is electrically connected to the output voltage, and whose output end is electrically connected to the input end of the Buck nonlinear dynamic controller and the input end of the Boost voltage outer loop PID control circuit, is used for sampling and compensating the output voltage.

[0093] Before the Boost voltage outer loop PID calculation, the system needs to sample the instantaneous output voltage V OUT , and compensate for it. The role of compensation is to provide more adjustment margin for the system and increase adjustment flexibility.

[0094] On the basis of the above embodiments, this embodiment also includes PWM (Pulse Width Modulation) and driving;

[0095] The input end of the PWM is electrically connected to the output end of the Buck nonlinear dynamic controller and the output end of the Boost current inner loop PID control circuit;

[0096] The output terminal of the PWM is electrically connected to the input terminal of the drive;

[0097] The output end of the driver is electrically connected to the input end of the Buck-Boost circuit.

[0098] like Figure 1As shown, the Buck nonlinear dynamic controller generates an analog control signal of the Buck switch and a driving control signal. The analog control signal of the Buck switch is converted and driven by PWM to form the control signal of the Buck switch.

[0099] The output of the boost voltage outer loop PID control circuit is sequentially subjected to PID calculation, PWM conversion and drive of the boost current inner loop PID control circuit to form a control signal of the boost switch to control the output voltage to track the reference voltage.

[0100] On the basis of the above embodiments, the Buck-Boost circuit described in this embodiment is a two-tube or four-tube structure.

[0101] This embodiment takes four tubes as an example and gives the topological structure of the Buck-Boost circuit as follows: Figure 3 shown.

[0102] The wide input Buck-Boost chopper control circuit provided in this embodiment is simulated below.

[0103] For the case where the input is powered by a DC generator, the generator's voltage output range is 400V to 1100V, and the generator's output voltage changes during operation, requiring the DC / DC voltage output to be stable at 800±10V.

[0104] The parameters of the Boost voltage outer loop PID regulation law are designed as follows: VP =0.8, outer loop integral coefficient k VI =0.001, outer loop differential coefficient k VD =0.03.

[0105] The parameters of the boost current inner loop PID regulation law are designed as follows: inner loop proportional coefficient k IP =0.5, inner loop integral coefficient k II =0.002, inner loop differential coefficient k ID =0.

[0106] Buck nonlinear dynamic controller parameters are designed as follows: speed adjustment coefficient k non =0.0005, maximum limit value e max =80.

[0107] The output voltage of the designed Buck-Boost chopper control circuit is investigated when the output of the DC generator is 380V, 700V and 1120V respectively. In addition, the output voltage of the designed Buck-Boost chopper control circuit is investigated when the output of the DC generator is 700V and the load changes by 90%, that is, the power changes by 90% in a large range.

[0108] The PWM device is the PWM Generator (2-Level) in SIMULINK, and the power unit uses the corresponding inverter. The simulation results are as follows Figures 4 to 7 shown.

[0109] Figure 4 This is a curve diagram of the output voltage of the chopper control circuit when the output of the DC generator is 380V, and the steady-state value is 798.7V. As can be seen from the figure, the output voltage of the chopper control circuit has no overshoot, and the steady-state error is small, which is much higher than the requirement that the DC / DC voltage output is stable at 800±10V.

[0110] Figure 5 This is a curve diagram of the output voltage of the chopper control circuit when the output of the DC generator is 700V, and the steady-state value is 800.5V. As can be seen from the figure, the output voltage of the chopper control circuit has no overshoot, and the steady-state error is small, which is much higher than the requirement that the DC / DC voltage output is stable at 800±10V.

[0111] Figure 6 This is a curve of the output voltage of the chopper control circuit when the output of the DC generator is 1120V, and the steady-state center value is 800.5V. In this case, ripples appear, and the peak-to-peak value of the ripples is less than 3V. As can be seen from the figure, the output voltage of the chopper control circuit has no overshoot, and the steady-state error is small, which is much higher than the requirement that the DC / DC voltage output is stable at 800±10V, and the peak-to-peak value of the ripples is only half of the requirement.

[0112] Figure 7 It is a curve diagram of the output voltage of the chopper control circuit when the output of the DC generator is 700V and the power changes from 12Kw to 1.2Kw at 3s. The steady-state value before 3s is 801.4V, and the steady-state value before 3s is 800.6V. It can be seen from the figure that the output voltage of the chopper control circuit has no overshoot, the steady-state error is small, and it is much higher than the requirement that the voltage output of the DC / DC is stable at 800±10V. When the power change reaches 90%, the output voltage of the chopper control circuit is almost unaffected, which shows that the chopper control circuit provided in this embodiment has good performance.

[0113] The wide-input Buck-Boost chopping control method provided by the present invention is described below. The wide-input Buck-Boost chopping control method described below and the wide-input Buck-Boost chopping control circuit described above can be referred to each other.

[0114] like Figure 8 As shown, the method includes:

[0115] Step 801, performing nonlinear dynamic calculation according to the current input voltage, the reference voltage and the most recent output voltage of the Buck-Boost circuit to obtain a control signal of the Buck switch;

[0116] Step 802, performing PID operation on the most recent output voltage of the Buck-Boost circuit and the reference voltage to obtain a reference current;

[0117] Step 803, performing PID operation on the reference current and the current input current, and outputting a control signal of the Boost switch;

[0118] Step 804: Acquire the current output voltage of the Buck-Boost circuit according to the control signal of the Buck switch, the control signal of the Boost switch and the most recent output voltage of the Buck-Boost circuit.

[0119] This embodiment uses a Buck nonlinear dynamic controller in a Buck-Boost chopper control circuit to perform nonlinear dynamic calculations on the input voltage, the reference voltage, and the output voltage to obtain a control signal of a Buck switch that controls the output voltage, thereby utilizing the simplest Buck-Boost topology to output a stable voltage with high precision over a wide input voltage range and a large power variation range.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wide input Buck-Boost chopper control circuit, characterized in that: include: Buck-Boost circuit, used to step down or boost the input voltage; A Buck nonlinear dynamic controller, the input end of which is electrically connected to the output end of the Buck-Boost circuit, and the output end of which is electrically connected to the input end of the Buck-Boost circuit; The Buck nonlinear dynamic controller is used to perform nonlinear dynamic calculation according to the input voltage, the reference voltage and the output voltage of the Buck-Boost circuit, and output a control signal of the Buck switch; A Boost voltage outer loop PID control circuit, whose input end is electrically connected to the output end of the Buck-Boost circuit, and is used to perform PID operation on the output voltage and the reference voltage to obtain a reference current; A boost current inner loop PID control circuit, whose input end is electrically connected to the output end of the boost voltage outer loop PID control circuit, and whose output end is electrically connected to the buck-boost circuit, is used to perform PID operation on the reference current and the input current, and output a control signal of the boost switch; The Buck nonlinear dynamic controller comprises: A limiting circuit, used for limiting the deviation between the reference voltage and the output voltage; a multiplication calculator, whose input end is electrically connected to the output end of the amplitude limiting circuit, and is used to multiply the limited deviation and the input voltage; An integral calculator, the input end of which is electrically connected to the output end of the multiplication calculator, and the output end of which is electrically connected to the input end of the Buck-Boost circuit, and is used to integrate the product of the limited deviation and the input voltage after multiplying it by a preset constant; The limiting circuit limits the deviation between the reference voltage and the output voltage by the following formula: Wherein, e is the deviation between the reference voltage and the output voltage, e is the deviation after limiting, and e max Determined by the range of e and the adjustment speed of e; The output of the integral calculator is calculated by the following formula: Among them, u buck is the output of the integral calculator, k non is the preset constant, V IN is the input voltage, is the deviation after restriction.

2. The wide input Buck-Boost chopper control circuit according to claim 1, characterized in that: It also includes an input current sampling and compensation circuit, and a resistor; The input end of the resistor is electrically connected to the input voltage, and the output end is electrically connected to the input end of the Buck-Boost circuit; The input end of the input current sampling and compensation circuit is electrically connected to the input end of the resistor and connected to the output end of the resistor; The output end of the input current sampling and compensation circuit is electrically connected to the input end of the Boost current inner loop PID control circuit; The input current sampling and compensation circuit is used for sampling and compensating the input current.

3. The wide input Buck-Boost chopper control circuit according to claim 2, characterized in that: The Boost voltage outer loop PID control circuit is used to calculate the deviation between the reference voltage and the output voltage, and output a reference current; The Boost current inner loop PID control circuit is used to calculate the deviation between the reference current and the input current output by the input current sampling and compensation circuit, and output a control signal of the Boost switch.

4. The wide input Buck-Boost chopper control circuit according to claim 2, characterized in that: Also includes: An input voltage sampling and compensation circuit, the input end of which is electrically connected to the input voltage, and the output end of which is electrically connected to the input end of the Buck nonlinear dynamic controller and the input end of the resistor, for sampling and compensating the input voltage; An output voltage sampling and compensation circuit, whose input end is electrically connected to the output voltage, and whose output end is electrically connected to the input end of the Buck nonlinear dynamic controller and the input end of the Boost voltage outer loop PID control circuit, is used for sampling and compensating the output voltage.

5. The wide input Buck-Boost chopper control circuit according to claim 1, characterized in that: It also includes PWM and drive; The input end of the PWM is electrically connected to the output end of the Buck nonlinear dynamic controller and the output end of the Boost current inner loop PID control circuit; The output terminal of the PWM is electrically connected to the input terminal of the drive; The output end of the driver is electrically connected to the input end of the Buck-Boost circuit.

6. The wide input Buck-Boost chopper control circuit according to claim 1, characterized in that: The Buck-Boost circuit is a two-tube or four-tube structure.

7. A wide input Buck-Boost chopping control method, characterized in that: The wide input Buck-Boost chopper control circuit as claimed in claim 1 comprises: Perform nonlinear dynamic calculation based on the current input voltage, reference voltage and the most recent output voltage of the Buck-Boost circuit to obtain the control signal of the Buck switch; Performing PID operation on the most recent output voltage of the Buck-Boost circuit and the reference voltage to obtain a reference current; Performing PID operation on the reference current and the current input current, and outputting a control signal of the Boost switch; The current output voltage of the Buck-Boost circuit is obtained according to the control signal of the Buck switch, the control signal of the Boost switch and the most recent output voltage of the Buck-Boost circuit.

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