WO2023005159A1

WO2023005159A1 - Control method and control apparatus for conversion circuit

Info

Publication number: WO2023005159A1
Application number: PCT/CN2022/070968
Authority: WO
Inventors: 陈文佳; 吴庆彬; 陈钦鸿
Original assignee: 科华数据股份有限公司; 漳州科华电气技术有限公司
Priority date: 2021-07-30
Filing date: 2022-01-10
Publication date: 2023-02-02
Also published as: CN113691136B; CN113691136A

Abstract

A control method and control apparatus for a conversion circuit. The control method comprises: acquiring an electrical parameter of a conversion circuit and a preset value corresponding to the electrical parameter; obtaining a first control quantity on the basis of the electrical parameter and the preset value; performing proportional adjustment and amplitude limiting processing on the first control quantity to obtain a second control quantity, performing amplitude limiting processing on the first control quantity to obtain a third control quantity, and making the second control quantity and/or the third control quantity linearly change along with the first control quantity; and respectively controlling a buck module and a boost module by using the second control quantity and the third control quantity. The control method and the control apparatus are suitable for preventing overvoltage from occurring for an output voltage of a conversion circuit, simplifying the control complexity and improving the operation stability of the circuit.

Description

A control method and control device for a conversion circuit

This patent application claims priority to Chinese Patent Application No. CN202110870329.3 filed on July 30, 2021. The disclosure of the prior application is incorporated by reference in its entirety into this application.

technical field

The present application relates to the technical field of conversion circuit control, in particular to a control method and a control device for a conversion circuit.

Background technique

The existing dual-inductance current-type push-pull circuit (push-pull circuit refers to the output circuit connected between two transistors of different polarities) is shown in Figure 1. The characteristics of this topology are: in order to provide a freewheeling path for the inductor current , the duty cycle of the switches S1 and S2 (the duty cycle refers to the percentage of the time the circuit is turned on to the entire circuit duty cycle) needs to have an overlapping area, so the duty cycles of the switches S1 and S2 are both greater than 0.5. Generally speaking, closed-loop control of the input current can be used to make the above-mentioned push-pull circuit work stably. The current closed-loop control loop is shown in Figure 2. In the case of sufficient load, the current closed-loop can make the The push-pull circuit works stably.

However, in the case of light load or high input voltage, since the minimum duty cycle has been limited to more than 0.5, the output voltage can only be reduced to the minimum value corresponding to the duty cycle of 0.5, which cannot be reduced to meet the control requirements. Therefore, the voltage value is continuously raised due to uncontrolled, unable to stabilize at the required operating point, which eventually leads to overvoltage of the output voltage.

technical problem

The purpose of this application is to overcome at least one defect or problem in the background technology, and provide a control method and control device for a conversion circuit, which is suitable for effectively controlling the output voltage of a dual-inductance current-type push-pull circuit, preventing the output voltage from overvoltage, and can simplify the control complexity and improve the stability of the circuit operation.

technical solution

In order to achieve the above object, the first aspect of the present application provides a control method for a conversion circuit, the circuit includes a first switch, a second switch, a third switch and two inductors; The inductor constitutes a step-down module, and the second switch and the third switch are suitable for forming a boost module with the two inductors; the method includes: obtaining one or more electrical parameters of the circuit, and presetting One or more preset values set and corresponding to each of the electrical parameters; wherein, the electrical parameters include at least the actual output voltage value of the circuit, and the preset values include at least the actual output voltage value corresponding to the actual output voltage value. The first voltage preset value corresponding to the voltage value; the first control amount is obtained based on the acquired electrical parameters and the preset value; the first control amount is proportionally adjusted and the first limit processing is performed to obtain the second control amount, performing second limiting processing on the first control amount to obtain a third control amount, and making the second control amount and/or the third control amount follow the linear change of the first control amount; using The second control variable and the third control variable respectively control the step-down module and the boost module.

In a possible implementation manner, the electrical parameter further includes an actual input current value of the circuit, and the preset value further includes a first current preset value corresponding to the actual input current value; Obtaining the first control amount from the acquired electrical parameter and the preset value includes: inputting the actual output voltage value and the first voltage preset value as a first feedback amount and a first given amount into a first Closed-loop control module; the actual input current value, and the value multiplied by the first current preset value and the output of the first closed-loop control module are respectively input into the second feedback quantity and the second given quantity as the second feedback quantity and the second given quantity A second closed-loop control module: using the output quantity of the second closed-loop control module as the first control quantity.

In a possible implementation manner, it is defined that in the process of obtaining the second control quantity, the proportional coefficient for performing proportional adjustment and first limit processing on the first control variable is K1, and the first limit processing range is is A1-A2; define that in the process of obtaining the third control quantity, the second limit processing range for performing the second limit processing on the first control quantity is B1-B2; wherein, the A1 and the Said A2 is 0 and 1 respectively; said B1 is greater than 0.5 and the product of said B1 and said K1 is 1; said B2 is less than 1.

In a possible implementation manner, the first switch, the second switch, and the third switch are all controllable switches adapted to be modulated by a PWM signal; the first control amount, the second Both the control quantity and the third control quantity are PWM signals; wherein, the second control quantity is the first PWM signal used to control the first switch; the third control quantity includes the signals used to control the The second PWM signal and the third PWM signal of the second switch and the third switch; the second PWM signal and the third PWM signal have the same magnitude and a phase difference of 180°.

In a possible implementation manner, the circuit is used to boost the DC input power and output it, and includes an inverter unit, a transformer, and a rectifier unit coupled in sequence; the inverter unit includes a first diode, The first switch, the second switch, the third switch, and the first inductance and the second inductance constituting the two inductances, and form a first branch, a second branch and a third branch; The first branch includes the first switch and the first diode connected in series, the first switch is connected to the positive pole of the input power supply, and the anode of the first diode is connected to the The negative pole of the input power supply; the second branch includes the first inductance and the second switch connected in series; the first inductance connects the common point of the first switch and the first diode , the second switch is connected to the negative pole of the input power supply; the third branch includes the second inductor and the third switch connected in series, and the second inductor connects the first switch and the The common point of the first diode, the third switch is connected to the negative pole of the input power supply; the primary winding of the transformer is connected to the common point of the second switch and the first inductor, and the first The common point of the three switches and the second inductor; the input end of the rectification unit is connected to the secondary winding of the transformer, and the output end of the rectification unit outputs DC power.

To achieve the above object, the second aspect of the present application provides a control device for a conversion circuit, the circuit includes a first switch, a second switch, a third switch and two inductors; The inductor constitutes a step-down module, and the second switch and the third switch are suitable for forming a boost module with the two inductors; the device includes: an acquisition unit, configured to acquire one or more of the circuits Electrical parameters, and one or more preset values preset and corresponding to each of the electrical parameters; wherein, the electrical parameters include at least the actual output voltage value of the circuit, and the preset values include at least a first voltage preset value corresponding to the actual output voltage value; a first generation unit, configured to calculate a first control amount based on the obtained electrical parameter and the preset value; and a second generation unit, It is used to perform proportional adjustment and first limit processing on the first control variable to obtain a second control variable for controlling the step-down module, and is also used to perform second limit processing on the first control variable to obtain It is used to control the third control quantity of the boost module, and make the second control quantity and/or the third control quantity linearly change following the first control quantity.

In a possible implementation manner, the electrical parameter acquired by the acquisition unit also includes the actual input current value of the circuit, and the preset value acquired by the acquisition unit further includes The corresponding first current preset value; the first generation unit includes a first closed-loop control module and a second closed-loop control module; the first feedback amount and the first given amount of the first closed-loop control module are respectively the actual The output voltage value and the first voltage preset value, the output quantity of the first closed-loop control module is an adjustment coefficient; the second feedback quantity and the second given quantity of the second closed-loop control module are respectively the actual The input current value, and the value obtained by multiplying the first current preset value by the adjustment coefficient, the output quantity of the second closed-loop control module is the first control quantity.

In a possible implementation manner, the second generation unit includes a first ratio adjustment module, a first limiter processing module, and a second limiter processing module; the first ratio adjustment module and the first limiter The processing module is used to respectively perform proportional adjustment and first limit processing on the first control amount to obtain the second control amount; wherein, the proportional coefficient of the first proportional adjustment module is K1, and the first limit The limiting range of the amplitude processing module is 0-1; the second limiting processing module is used to perform second limiting processing on the first control quantity and obtain the third control quantity; wherein, the second The limit range of the limit processing module is B1-B2; the B1 is greater than 0.5 and the product of the B1 and the K1 is 1; the B2 is less than 1.

Beneficial effect

Compared with the prior art, the beneficial effects of the present application are:

(1) The conversion circuit includes several switches and two inductors. The first switch is suitable for forming a step-down module with the corresponding inductor, and the second switch and the third switch are suitable for forming a boost module with the corresponding inductor. Compared with the traditional Dual-inductance current-type push-pull circuit, because the above-mentioned improved circuit has a step-down module, the output voltage of the entire conversion circuit can be reduced by conducting conduction control on the first switch, so it is suitable for the dual-inductance current-type push-pull circuit The output voltage is effectively controlled to prevent the output voltage from overvoltage, and also makes the conversion circuit suitable for wide-range voltage regulation.

Not only that, on the basis of the improved circuit, the control method of the present application also has the advantage of simplifying the control complexity. Specifically, in the conversion circuit including two switches with substantially different control logics, in the prior art, it is usually necessary to set a plurality of different input values to obtain the control values of each switch. For example, only for voltage control, it is usually necessary to set an intermediate voltage value between the input voltage value and the output voltage value, and then use the input voltage value and the intermediate voltage value to obtain the control value of one of the switches, and then use the output voltage value and The intermediate voltage value gets the control amount of another switch. This will make the control process more complicated in the scenario where the application needs to realize the normal operation of the conversion circuit and also need to prevent the output voltage of the conversion circuit from overvoltage.

To this end, the control method of the present application first obtains the electrical parameters of the circuit and the corresponding preset values, and obtains a first control quantity that can reflect the overall control requirements based on these electrical parameters and preset values, wherein the electrical parameters include at least the actual For the output voltage value, the preset value includes at least the first voltage preset value, and control factors for preventing the output voltage from overvoltage can be fully added to the obtained first control quantity. Subsequently, the sum of the second control quantity used to control the step-down module is obtained by sequentially performing proportional adjustment and first limit processing on the first control quantity, and the sum of the second control quantity used to control the boost module is obtained by performing the second limit treatment on the first control quantity. The third control quantity of the module makes the whole circuit in the full load segment or the full input voltage range, the second control quantity and the third control quantity obtained after processing follow the linear change of the first control quantity, which effectively prevents the The sudden change of the current or voltage of the conversion circuit leads to a sudden change of the current or voltage, which ensures the stability of the conversion circuit during the control process.

Generally speaking, the control method of the present application can not only implement various basic control strategies (such as controlling the input current, input voltage or output voltage and other electrical parameters to keep constant) to ensure the normal operation of the conversion circuit, but also can further pass The conduction control of the first switch prevents the output voltage of the conversion circuit from overvoltage, effectively reduces the complexity of the control process, and improves the stability.

(2) The electrical parameter also includes the actual input current value, and the preset value also includes the first current preset value, so that the basic control strategy of controlling the constant input current can be used to ensure the normal operation of the conversion circuit, and can effectively prevent the output of the circuit Voltage overvoltage.

In addition, by configuring double closed-loop control modules, that is, the first closed-loop control module and the second closed-loop control module, the first closed-loop control module outputs the adjustment coefficient according to the feedback given deviation of the actual output voltage value, so as to use the adjustment coefficient to adjust the second The given current value of the closed-loop control module is corrected, so that the first control quantity output by the second closed-loop control module can be affected by the feedback of the actual output voltage value, so that the output can satisfy both the basic control strategy and the anti-output voltage The first control amount of overpressure.

(3) The product of B1 and proportional coefficient K1 in the second limiting range is 1, and the third control quantity is always limited to the minimum limit value before the second control quantity linearly increases to 1 with the first control quantity. At the same time, after the second control quantity reaches and stabilizes at 1, the third control quantity begins to increase linearly. In other words, the above configuration makes the curves of the second control quantity and the third control quantity with the first control quantity appear at the same time, and the first switch of the step-down module and the second switch and the third switch of the boost module will not be adjusted at the same time. The situation further improves the stability of the conversion circuit in the control process.

(4) The first switch, the second switch and the third switch are all controllable switches suitable for modulation by a PWM signal, and the inverter unit includes a first diode, a first diode, a first switch and a corresponding inductance Together constitute the equivalent basic Buck circuit, thus forming a new topology on the basis of the traditional dual-inductance current-type push-pull circuit, and is suitable for preventing the output voltage from overvoltage through the above control method and facilitating the stable control of the conversion circuit. The conversion circuit can work normally.

(5) The control device corresponds to the aforementioned control method, and thus has the same advantages as the control method.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings that need to be used in the description of the embodiments. Obviously, the drawings in the following description are some embodiments of the present application. Those of ordinary skill in the art can also obtain other drawings based on these drawings on the premise of not paying creative efforts.

Fig. 1 is the structural diagram of existing dual inductance current type push-pull circuit;

Fig. 2 is a kind of typical control loop of the circuit shown in Fig. 1;

Fig. 3 is the structural diagram of the conversion circuit of the embodiment of the present application;

FIG. 4 is a control loop structural diagram of a first generating unit according to an embodiment of the present application;

FIG. 5 is a schematic diagram of the processing process of the second generation unit according to the embodiment of the present application;

FIG. 6 is a result diagram of processing the first control amount according to the embodiment of the present application.

Embodiment of this application

The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are preferred embodiments of the present application and should not be seen as excluding other embodiments. Based on the embodiments of the present application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present application.

In the claims, specification and drawings of this application, unless otherwise clearly defined, the terms "first", "second" or "third" are used to distinguish different objects, rather than to describe specific order.

In the claims, specification and drawings of the present application, if the terms "comprising", "having" and their variants are used, it is intended to mean "including but not limited to".

In the claims, description and drawings of this application, unless otherwise clearly defined, the term "connection" may include direct connection or indirect connection; if the term "coupling" is used, it means that two electrical modules are connected It has a specific circuit function after connection.

Referring to Figure 3, the embodiment of the present application firstly provides a step-up conversion circuit, which is used to boost the DC input power and output it, and includes an inverter unit, a transformer and a rectification unit coupled in sequence, thus forming an isolated type boost topology. In this embodiment, the input power source is a direct current power source, specifically, various types of batteries.

The inverter unit includes a first diode D1, a first switch S1, a second switch S2, a third switch S3, a first inductance L1 and a second inductance L2, and forms a first branch, a second branch and a third branch. branch road. The first switch S1 is adapted to form a step-down module with the first inductor L1 or the second inductor L2, and the second switch S2 and the third switch S3 are adapted to form a boost module with the first inductor L1 and the second inductor L2. In this embodiment, the first switch S1 , the first diode D1 and the second switch S2 are all semiconductor controllable switches, which are suitable for modulation by a PWM signal, and specifically may be MOS transistors. Among them, the PWM signal refers to a pulse width modulation signal (PWM, the English full name is Pulse width modulation).

Specifically, the first branch includes a first switch S1 and a first diode D1 connected in series, the first switch S1 is connected to the positive pole of the input power supply, and the anode of the first diode D1 is connected to the negative pole of the input power supply. The second branch includes a first inductor L1 and a second switch S2 connected in series, the first inductor L1 is connected to the common point of the first switch S1 and the first diode D1, and the second switch S2 is connected to the negative pole of the input power. The third branch includes a second inductor L2 and a third switch S3 connected in series, the second inductor L2 is connected to the common point of the first switch S1 and the first diode D1, and the third switch S3 is connected to the negative pole of the input power.

The primary winding of the transformer is connected to the common point of the second switch S2 and the first inductor L1, and the common point of the third switch S3 and the second inductor L2. The rectification unit is a bridge rectification circuit composed of four rectification diodes (D2, D3, D4, and D5). The input end of the rectification unit is connected to the secondary winding of the transformer, and the output end of the rectification unit outputs boosted DC power.

Since the working process of the isolated boost topology is a prior art and is not the focus of this application, it will not be introduced in detail in this application. However, according to the above description and accompanying drawings, it can be seen that the conversion circuit of the embodiment of the present application includes several switches and two inductors. and the third switch S3 are suitable for forming a boost module with the corresponding inductance. Compared with the traditional dual-inductance current-type push-pull circuit, the above-mentioned improved circuit can be turned on by turning on the first switch S1 because it has a step-down module. Control to reduce the output voltage of the entire conversion circuit, so that it is suitable for effectively controlling the output voltage of the dual-inductance current-type push-pull circuit, preventing the output voltage from overvoltage, and also making the conversion circuit suitable for wide-range voltage regulation.

3-5, based on the conversion circuit described above, the embodiment of the present application also provides a control method for the conversion circuit, including the following steps:

Acquiring one or more electrical parameters of the circuit, and one or more preset values corresponding to each electrical parameter. Wherein, the electrical parameter includes at least an actual output voltage value Ubus of the circuit, and the preset value includes at least a first voltage preset value Ubusref corresponding to the actual output voltage value Ubus. It can be understood that the electrical parameter includes an actual output voltage value, an actual input voltage value, an actual output current value or an actual input current value.

The first control quantity is obtained based on the acquired electrical parameters and preset values. It can be understood that, based on the electrical parameters and preset values, it is generally possible to input each electrical parameter and preset value as a feedback value and a given value to the corresponding closed-loop control loop, and to couple each closed-loop control loop correspondingly. To obtain the first control amount, the specific manner of this embodiment will be described in detail below.

Sequentially perform proportional adjustment and first limit processing on the first control amount to obtain the second control amount, perform second limit processing on the first control amount to obtain the third control amount, and make the second control amount and/or the third control amount The quantity changes linearly with the first control quantity. In this embodiment, the first control quantity, the second control quantity and the third control quantity are all PWM signals. Wherein, the first control quantity is the overall PWM signal D, the second control quantity is the first PWM signal DS1 used to control the first switch S1, and the third control quantity includes the signals used to control the second switch S2 and the third switch S3 respectively. The second PWM signal DS2 and the third PWM signal DS3. The second PWM signal DS2 and the third PWM signal DS3 have the same magnitude and a phase difference of 180°.

The first switch S1 of the buck module and the second switch S2 and the third switch S3 of the boost module are respectively controlled by using the second control amount and the third control amount.

In this embodiment, the control method has the advantage of simplifying control complexity based on the improved circuit. Specifically, the control method of the present application first obtains the electrical parameters of the circuit and the corresponding preset values, and based on these electrical parameters and preset values, obtains a first control quantity that can reflect the overall control requirements, wherein the electrical parameters include at least The actual output voltage value Ubus, the preset value at least includes the first voltage preset value Ubusref, and control factors for preventing output voltage overvoltage can be fully added to the obtained first control variable. Subsequently, the second control quantity used to control the step-down module is obtained by sequentially performing proportional adjustment and limiting processing on the first control quantity, and the third control quantity used to control the boost module is obtained by performing limiting processing on the first control quantity , so that the entire circuit is in the full load segment or the full input voltage range, the second and third control quantities obtained after processing follow the linear change of the first control quantity, which effectively prevents the conversion circuit due to sudden changes in the control signal. The sudden change of current or voltage ensures the stability of the conversion circuit in the control process.

Generally speaking, the control method of the present application can not only implement various basic control strategies (such as the basic control strategy of controlling the input current, input voltage or output voltage and other electrical parameters to keep constant) to ensure the normal operation of the conversion circuit, the control means are diversified , the overvoltage of the output voltage of the conversion circuit can be further prevented by controlling the conduction of the first switch S1, which effectively reduces the complexity of the control process and improves the stability.

In addition, in this embodiment, the electrical parameter also includes the actual input current value Ibat of the circuit, and the preset value also includes the first current preset value Ibatref corresponding to the actual input current value Ibat, so that the basic control of controlling the input current constant Strategies to ensure the normal operation of the conversion circuit, and can effectively prevent the output voltage of the circuit from overvoltage. It can be understood that, in other embodiments, it is still feasible to replace the actual input current value Ibat with other electrical parameters such as input voltage or output voltage to form other different basic control strategies.

In this embodiment, obtaining the first control amount based on the obtained electrical parameters and preset values includes the following steps:

The actual output voltage value Ubus and the first voltage preset value Ubusref are input into the first closed-loop control module as the first feedback quantity and the first given quantity respectively, and the output quantity of the first closed-loop control module is an adjustment coefficient X.

The actual input current value Ibat, and the value obtained by multiplying the first current preset value Ibatref by the output of the first closed-loop control module (that is, the value obtained by multiplying the first current preset value Ibatref by the adjustment coefficient X) are respectively used as The second feedback quantity and the second given quantity are input into the second closed-loop control module.

The output quantity of the second closed-loop control module is used as the first control quantity, that is, the overall PWM signal D.

Therefore, by configuring the double closed-loop control module, that is, the first closed-loop control module and the second closed-loop control module, the first closed-loop control module outputs the adjustment coefficient X according to the feedback given deviation of the actual output voltage value Ubus, so as to pass the adjustment coefficient X Correct the given current value of the second closed-loop control module, so that the first control quantity output by the second closed-loop control module can be affected by the feedback of the actual output voltage value Ubus, so that the output can satisfy the basic control strategy and can The first control amount for preventing output voltage overvoltage is satisfied.

Specifically, for the proportional adjustment and limiting processing, the embodiment of the present application also has the following configuration: define the proportional coefficient for sequentially performing proportional adjustment and first limiting processing on the first controlled variable in the process of obtaining the second controlled variable as K1. The first limiting processing range is A1-A2. It is defined that in the process of obtaining the third control variable, the range of the second limit processing for performing the second limit processing on the first control variable is B1-B2. Among them, A1 and A2 are 0 and 1 respectively, B1 is greater than 0.5 and the product of B1 and K1 is 1, and B2 is less than 1. In this embodiment, the proportionality coefficient K1 may be 1/0.52, and B1 may be 0.52.

Referring to Fig. 6, in this embodiment, the product of B1 and proportional coefficient K1 in the second limiting range is 1, and the second control amount increases linearly with the first control amount to 1, and the third control amount is always limited at Minimum clipping value. At the same time, after the second control quantity reaches and stabilizes at 1, the third control quantity begins to increase linearly. In other words, the above configuration makes the curves of the second control amount and the third control amount with the first control amount appear at the same time, and the first switch S1 of the step-down module and the second switch S2 and the third switch of the step-up module do not appear. The simultaneous adjustment of S3 further improves the stability of the conversion circuit in the control process.

Correspondingly, the embodiment of the present application further provides a control device corresponding to the control method, the control device is also used to control the aforementioned conversion circuit, and includes an acquisition unit, a first generation unit, and a second generation unit.

The acquiring unit is used to acquire one or more electrical parameters of the circuit, and one or more preset values corresponding to each electrical parameter. Wherein, the electrical parameter includes at least an actual output voltage value Ubus of the circuit, and the preset value includes at least a first voltage preset value Ubusref corresponding to the actual output voltage value Ubus.

The first generation unit is used to calculate and obtain the first control amount based on the acquired electrical parameters and preset values.

The second generating unit is used to sequentially perform proportional adjustment and first limit processing on the first control variable to obtain a second control variable for controlling the step-down module, and is also used to perform second limit processing on the first control variable A third control variable for controlling the boost module is obtained, and the second control variable and/or the third control variable follow the first control variable to change linearly. In this embodiment, the first control quantity, the second control quantity and the third control quantity are all PWM signals. Wherein, the first control quantity is the overall PWM signal D, the second control quantity is the first PWM signal DS1 used to control the first switch S1, and the third control quantity includes the signals used to control the second switch S2 and the third switch S3 respectively. The second PWM signal DS2 and the third PWM signal DS3. The second PWM signal DS2 and the third PWM signal DS3 have the same magnitude and a phase difference of 180°.

Specifically, the electrical parameter obtained by the obtaining unit also includes an actual input current value Ibat of the circuit, and the preset value obtained by the obtaining unit also includes a first current preset value Ibatref corresponding to the actual input current value Ibat. The first generating unit includes a first closed-loop control module and a second closed-loop control module. The first feedback quantity and the first given quantity of the first closed-loop control module are the actual output voltage value Ubus and the first voltage preset value Ubusref respectively, and the output quantity of the first closed-loop control module is an adjustment coefficient X. The second feedback quantity and the second given quantity of the second closed-loop control module are respectively the actual input current value Ibat, and the value multiplied by the first current preset value Ibatref and the adjustment coefficient X, and the output quantity of the second closed-loop control module is The first control quantity is the overall PWM signal D.

Specifically, the second generation unit includes a first ratio adjustment module, a first limit processing module, and a second limit processing module. The first proportional adjustment module is used for proportional adjustment of the first control amount, and the first limiter processing module is used for performing first limiter processing on the proportionally adjusted first control amount to obtain a second control amount. Wherein, the proportional coefficient of the first proportional adjustment module is K1, and the limiting range of the first limiting processing module is 0-1. The second limiting processing module is used to perform second limiting processing on the first control variable to obtain the third control variable. Wherein, the limiting range of the second limiting processing module is B1-B2; B1 is greater than 0.5 and the product of B1 and K1 is 1; B2 is less than 1.

It can be seen that the control device of the conversion circuit in this embodiment has a material structure corresponding to the above-mentioned control method, and thus has the same advantages as the control method, and will not be described in detail in this embodiment.

The above descriptions and descriptions of the embodiments are used to explain the protection scope of the present application, but are not intended to limit the protection scope of the present application. Through the inspiration of the present application or the above-mentioned embodiments, those of ordinary skill in the art can obtain the understanding of the embodiments of the present application through logical analysis, reasoning or limited experiments in combination with common knowledge, common technical knowledge in the field and/or prior art. Or the modification, equivalent replacement or other improvements of some of the technical features shall be included in the protection scope of the present application.

Claims

A control method for a conversion circuit, characterized in that: the circuit includes a first switch, a second switch, a third switch and two inductors; the first switch is suitable for forming a step-down module with one of the inductors, so The second switch and the third switch are adapted to form a boost module with the two inductors;

The methods include:

Acquire one or more electrical parameters of the circuit, and one or more preset values that are preset and correspond to each of the electrical parameters; wherein, the electrical parameters include at least the actual output voltage value of the circuit , the preset value includes at least a first voltage preset value corresponding to the actual output voltage value;

obtaining a first control amount based on the acquired electrical parameter and the preset value;

performing proportional adjustment and first limiting processing on the first control amount to obtain a second control amount, performing second limiting processing on the first control amount to obtain a third control amount, and making the second control amount and /or the third control quantity changes linearly following the first control quantity;

The step-down module and the step-up module are respectively controlled by using the second control quantity and the third control quantity.
A control method for a conversion circuit according to claim 1, wherein the electrical parameter also includes the actual input current value of the circuit, and the preset value also includes a value corresponding to the actual input current value. The first current preset value;

The obtaining the first control amount based on the obtained electrical parameter and the preset value includes:

inputting the actual output voltage value and the first preset voltage value as a first feedback amount and a first given amount into a first closed-loop control module;

The actual input current value, and the value obtained by multiplying the first current preset value by the output of the first closed-loop control module are respectively input into the second closed-loop control module as the second feedback quantity and the second given quantity ;

The output quantity of the second closed-loop control module is used as the first control quantity.
A control method for a conversion circuit as claimed in claim 1, characterized in that:

It is defined that in the process of obtaining the second control quantity, the proportional coefficient for performing proportional adjustment and first limiting processing on the first control quantity is K1, and the first limiting processing range is A1-A2; In the process of the third control amount, the second limit processing range for performing the second limit processing on the first control amount is B1-B2;

Wherein, the A1 and the A2 are 0 and 1 respectively; the B1 is greater than 0.5 and the product of the B1 and the K1 is 1; the B2 is less than 1.
A control method for a conversion circuit according to any one of claims 1-3, characterized in that: said first switch, said second switch and said third switch are all suitable for modulation by PWM signal controllable switch;

The first control quantity, the second control quantity and the third control quantity are all PWM signals;

Wherein, the second control amount is a first PWM signal used to control the first switch; the third control amount includes a second PWM signal used to control the second switch and the third switch respectively and a third PWM signal;

The second PWM signal and the third PWM signal have the same magnitude and a phase difference of 180°.
The control method of a conversion circuit according to claim 4, wherein the circuit is used to boost the DC input power and output it, and includes an inverter unit, a transformer and a rectification unit coupled in sequence;

The inverter unit includes a first diode, the first switch, the second switch, the third switch, and a first inductance and a second inductance forming two inductances, and forms a first branch Road, a second branch and a third branch; the first branch includes the first switch and the first diode connected in series with each other, the first switch is connected to the positive pole of the input power supply, The anode of the first diode is connected to the negative pole of the input power supply; the second branch circuit includes the first inductor and the second switch connected in series, and the first inductor is connected to the first The common point of the switch and the first diode, the second switch is connected to the negative pole of the input power supply; the third branch includes the second inductor and the third switch connected in series, so The second inductor is connected to the common point of the first switch and the first diode, and the third switch is connected to the negative pole of the input power supply;

The primary winding of the transformer is connected to a common point of the second switch and the first inductor, and, a common point of the third switch and the second inductor;

The input end of the rectification unit is connected to the secondary winding of the transformer, and the output end of the rectification unit outputs DC power.
A control device for a conversion circuit, characterized in that: the circuit includes a first switch, a second switch, a third switch and two inductors; the first switch is suitable for forming a step-down module with one of the inductors, so The second switch and the third switch are adapted to form a boost module with the two inductors;

The devices include:

An acquisition unit, configured to acquire one or more electrical parameters of the circuit, and one or more preset values corresponding to each of the electrical parameters; wherein, the electrical parameters include at least the electrical circuit The actual output voltage value, the preset value includes at least a first voltage preset value corresponding to the actual output voltage value;

a first generating unit, configured to calculate a first control amount based on the acquired electrical parameter and the preset value; and

The second generating unit is configured to perform proportional adjustment and first limit processing on the first control amount to obtain a second control amount for controlling the step-down module, and is also used to perform a second control amount on the first control amount The second clipping process obtains a third control variable used to control the boost module, and makes the second control variable and/or the third control variable linearly change following the first control variable.
A control device for a conversion circuit according to claim 6, characterized in that: the electrical parameter acquired by the acquisition unit also includes the actual input current value of the circuit, and the preset value acquired by the acquisition unit The value also includes a first current preset value corresponding to the actual input current value;

The first generation unit includes a first closed-loop control module and a second closed-loop control module;

The first feedback quantity and the first given quantity of the first closed-loop control module are respectively the actual output voltage value and the first preset voltage value, and the output quantity of the first closed-loop control module is an adjustment coefficient;

The second feedback amount and the second given amount of the second closed-loop control module are respectively the actual input current value, and the value obtained by multiplying the first current preset value by the adjustment coefficient, and the second The output quantity of the closed-loop control module is the first control quantity.
A control device for a conversion circuit according to claim 6, wherein the second generation unit includes a first ratio adjustment module, a first limiter processing module, and a second limiter processing module;

The first proportional adjustment module and the first limit processing module are used to respectively perform proportional adjustment and first limit processing on the first control amount and obtain the second control amount; wherein, the first The proportional coefficient of the proportional adjustment module is K1, and the limiting range of the first limiting processing module is 0-1;

The second limiting processing module is used to perform second limiting processing on the first control variable to obtain the third control variable; wherein, the limiting range of the second limiting processing module is B1-B2 ; the B1 is greater than 0.5 and the product of the B1 and the K1 is 1; the B2 is less than 1.
A control device for a conversion circuit according to any one of claims 6-8, characterized in that: said first switch, said second switch and said third switch are all suitable for modulation by PWM signal controllable switch;

The first control quantity, the second control quantity and the third control quantity are all PWM signals;

Wherein, the second control amount is a first PWM signal used to control the first switch; the third control amount includes a second PWM signal used to control the second switch and the third switch respectively and a third PWM signal;

The second PWM signal and the third PWM signal have the same magnitude and a phase difference of 180°.
A control device for a conversion circuit according to claim 9, wherein the circuit is used to boost the DC input power and output it, and includes an inverter unit, a transformer and a rectification unit coupled in sequence;

The inverter unit includes a first diode, the first switch, the second switch, the third switch, and a first inductance and a second inductance forming two inductances, and forms a first branch Road, a second branch and a third branch; the first branch includes the first switch and the first diode connected in series with each other, the first switch is connected to the positive pole of the input power supply, The anode of the first diode is connected to the negative pole of the input power supply; the second branch circuit includes the first inductor and the second switch connected in series; the first inductor is connected to the first The common point of the switch and the first diode, the second switch is connected to the negative pole of the input power supply; the third branch includes the second inductor and the third switch connected in series, so The second inductor is connected to the common point of the first switch and the first diode, and the third switch is connected to the negative pole of the input power supply;

The primary winding of the transformer is connected to a common point of the second switch and the first inductor, and, a common point of the third switch and the second inductor;

The input end of the rectification unit is connected to the secondary winding of the transformer, and the output end of the rectification unit outputs DC power.