Bus voltage control method, device and power supply system

Abstract

The present invention provides a bus voltage control method, a device, and a power supply system. The method is used to control the corresponding bus voltage by controlling a target power conversion circuit. The bus voltage control method includes: obtaining the bus voltage corresponding to the target power conversion circuit and the non-bus side current, and determining the control quantity corresponding to the double closed-loop control based on the bus voltage and the non-bus side current; the double closed-loop control is a control of voltage outer loop - current inner loop, and the current loop controller adopted by the current inner loop is a PI controller; determining a compensation control quantity according to the control error adopted in the double closed-loop control and the controller integral of the PI controller; the control error is the bus voltage error or the non-bus side current error; compensating the control quantity corresponding to the double closed-loop control based on the compensation control quantity to obtain a compensated control quantity, and controlling the target power conversion circuit according to the compensated control quantity. The present invention can effectively control the bus voltage.

Description

Technical Field

[0001] The present invention belongs to the technical field of circuit control, and more specifically, relates to a bus voltage control method, device, and power supply system. Background Art

[0002] In this field, the control of the bus voltage is usually achieved by controlling the power conversion circuit. In the traditional double-loop control algorithm used for controlling the power conversion circuit, the outer loop is the bus voltage loop, and the inner loop is the current loop. To ensure the dynamic control effect of the bus voltage, usually the inner current loop is a proportional controller. However, the proportional controller has an inherent static error and cannot achieve static error-free control of the current.

[0003] In the prior art, this problem is improved by changing the proportional controller of the inner current loop to a proportional-integral controller. However, after changing the inner current loop to a proportional-integral controller, the following defects exist:

[0004] Since some power conversion circuits cannot have negative energy flow, the output limit of the bus voltage loop is set to a range of [negative value approaching 0, +I bat_max . This output limit can easily cause the phenomenon of overvoltage of the bus because the controller of the inner current loop cannot cancel the integral during system no-load or light-load conditions, thereby affecting the effectiveness of the bus voltage control. Summary of the Invention

[0005] The purpose of the present invention is to provide a bus voltage control method, device, and power supply system to improve the effectiveness of the bus voltage control.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is to provide a bus voltage control method. The bus voltage control method is used to control the corresponding bus voltage by controlling the target power conversion circuit. The bus voltage control method includes:

[0007] Obtain the bus voltage corresponding to the target power conversion circuit and the non-bus side current, and determine the control quantity corresponding to the double-loop control based on the bus voltage and the non-bus side current;

[0008] Among them, the double-loop control is a control of voltage outer loop - current inner loop, and the current loop controller used in the current inner loop is a PI controller;

[0009] Determine the compensation control quantity according to the control error used in the double-loop control and the integral of the PI controller; wherein, the control error is the bus voltage error or the non-bus side current error;

[0010] Compensate the control quantity corresponding to the double closed-loop control based on the compensation control quantity to obtain the compensated control quantity, and control the target power conversion circuit according to the compensated control quantity.

[0011] In a possible implementation manner, the determining the control quantity corresponding to the double closed-loop control based on the bus voltage and the non-bus side current includes:

[0012] Determine the bus voltage error based on the bus voltage and a preset bus voltage reference value;

[0013] Input the bus voltage error into a preset voltage loop controller to obtain the reference value of the non-bus side current;

[0014] Determine the non-bus side current error based on the reference value of the non-bus side current and the non-bus side current;

[0015] Input the non-bus side current error into the PI controller to obtain the control quantity corresponding to the double closed-loop control.

[0016] In a possible implementation manner, the determining the bus voltage error based on the bus voltage and a preset bus voltage reference value includes:

[0017] Take the difference between the preset bus voltage reference value and the bus voltage as the bus voltage error.

[0018] In a possible implementation manner, the determining the non-bus side current error based on the reference value of the non-bus side current and the non-bus side current includes:

[0019] Take the difference between the reference value of the non-bus side current and the non-bus side current as the non-bus side current error.

[0020] In a possible implementation manner, the determining the compensation control quantity according to the control error adopted during the double closed-loop control and the controller integral of the PI controller includes:

[0021] Input the control error adopted during the double closed-loop control and the controller integral of the PI controller into a preset dynamic controller to obtain the compensation control quantity;

[0022] Wherein, the dynamic controller is used to generate the compensation control quantity with negative compensation according to the control error and the controller integral of the PI controller when the control error is less than zero.

[0023] In a possible implementation manner, when the control error is not less than zero, the compensation control quantity output by the dynamic controller is zero;

[0024] When the control error is less than zero, the compensation control quantity output by the dynamic controller is positively correlated with the control error and the absolute value of the integral of the controller.

[0025] In a possible implementation manner, compensating the control quantity corresponding to the double closed-loop control based on the compensation control quantity to obtain a compensated control quantity includes:

[0026] Superposing the compensation control quantity on the control quantity corresponding to the double closed-loop control to obtain a compensated control quantity.

[0027] In a possible implementation manner, controlling the target power conversion circuit according to the compensated control quantity includes:

[0028] Generating a modulation wave according to the compensated control quantity and sending the modulation wave to the switching tube of the target power conversion circuit to control the bus voltage by controlling the duty cycle of the switching tube.

[0029] On the other hand, the present invention also provides a bus voltage control device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned bus voltage control method are implemented.

[0030] On yet another aspect, the present invention also provides a power supply system, including a power conversion circuit and the bus voltage control device described above.

[0031] The beneficial effects of the bus voltage control method, device, and power supply system provided by the present invention are as follows:

[0032] Based on the traditional double closed-loop control, the present invention also calculates the compensation control quantity by combining the control error and the integral of the PI controller, so as to realize the compensation of the control quantity when the system (where the power conversion circuit is located) is no-load or lightly loaded and the PI controller cannot de-integrate. That is to say, the present invention effectively solves the problem of bus overvoltage during no-load or light load brought by the PI controller through the calculation of the compensation control quantity, thereby ensuring the effective control of the bus voltage. Description of the Drawings

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1Schematic diagram of the bus voltage control method provided by an embodiment of the present invention;

[0035] Figure 2 Schematic diagram of the control loop corresponding to the target power conversion circuit provided by an embodiment of the present invention;

[0036] Figure 3 Schematic diagram of the structure of the bus voltage control device provided by an embodiment of the present invention. Detailed implementation manners

[0037] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0038] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0039] Please refer to Figure 1 , Figure 1 Schematic diagram of the flow of the bus voltage control method provided by an embodiment of the present invention. The bus voltage control method is used to control the corresponding bus voltage by controlling the target power conversion circuit. The bus voltage control method includes:

[0040] S101: Obtain the bus voltage corresponding to the target power conversion circuit and the non-bus-side current, and determine the control quantity corresponding to the double closed-loop control based on the bus voltage and the non-bus-side current.

[0041] Among them, the double closed-loop control is a control of voltage outer loop - current inner loop, and the current loop controller adopted by the current inner loop is a PI controller (proportional integral controller).

[0042] In this embodiment, one side of the target power conversion circuit is the bus side, and the other side is the non-bus side. For example, in the battery boost control scenario (that is, the target power conversion circuit is a boost circuit), the battery side is the non-bus side, and the non-bus-side current is the battery discharge current. It should be noted here that the present invention is not limited to the battery boost control scenario, and it can be applied to any scenario that conforms to the content described in the background technology of the present invention.

[0043] In this embodiment, after obtaining the bus voltage and the non-bus-side current, the control quantity used in the double closed-loop control can be calculated based on the double closed-loop control method.

[0044] S102: Determine the compensation control quantity according to the control error adopted in the double closed-loop control and the controller integral of the PI controller. Among them, the control error is the bus voltage error or the non-bus-side current error.

[0045] Considering that the PI controller in the current inner loop may not be able to cancel the integral when the system is no-load or light-load, the present invention calculates a compensation control quantity by comprehensively considering the control error and the integral of the PI controller, so as to achieve the compensation of the control quantity corresponding to the aforementioned double closed-loop control, and further weaken the integral quantity of the PI controller when the PI controller in the current inner loop cannot cancel the integral, thereby avoiding the overvoltage problem of the bus.

[0046] In this embodiment, the control error is the error used in the double closed-loop control, which can be the bus voltage error used in the voltage outer loop control or the non-bus-side current error used in the current inner loop control, and is not limited herein.

[0047] S103: Compensate the control quantity corresponding to the double closed-loop control based on the compensation control quantity to obtain the compensated control quantity, and control the target power conversion circuit according to the compensated control quantity.

[0048] In this embodiment, the control quantity corresponding to the double closed-loop control can be compensated by the calculated compensation controller, and the target power conversion circuit is controlled based on the compensated control quantity.

[0049] As can be seen from the above description, the embodiment of the present invention also calculates a compensation control quantity by combining the control error and the integral of the PI controller on the basis of the traditional double closed-loop control, so as to achieve the compensation of the control quantity when the system (where the power conversion circuit is located) is no-load or light-load and the PI controller cannot cancel the integral. That is to say, the embodiment of the present invention effectively solves the bus overvoltage problem caused by the PI controller during no-load or light-load through the calculation of the compensation control quantity, thereby ensuring the effective control of the bus voltage.

[0050] In a possible implementation manner, please refer to Figure 2 ( Figure 2 taking the control error as the bus voltage error as an example), determining the control quantity corresponding to the double closed-loop control based on the bus voltage and the non-bus-side current includes:

[0051] Based on the bus voltage U bus and the preset bus voltage reference value U busref to determine the bus voltage error ΔU bus .

[0052] Input the bus voltage error ΔU bus into the preset voltage loop controller ( Figure 2 the voltage controller in is a PI controller, and it is not limited to this in actual application), and obtain the reference value of the non-bus-side current.

[0053] Based on the reference value of the non-bus-side current and the non-bus-side current I batDetermine the non-bus-side current error.

[0054] Input the non-bus-side current error into the PI controller to obtain the control quantity corresponding to the double closed-loop control.

[0055] In this embodiment, the voltage controller is not limited to Figure 2 the PI controller in, and other types of controllers can also be used according to the actual scenario, which is not limited here.

[0056] In a possible implementation, please refer to Figure 2 , and determine the bus voltage error based on the bus voltage and the preset bus voltage reference value, including:

[0057] Take the difference between the preset bus voltage reference value U busref and the bus voltage U bus as the bus voltage error ΔU bus .

[0058] In a possible implementation, please refer to Figure 2 , and determine the non-bus-side current error based on the reference value of the non-bus-side current and the non-bus-side current, including:

[0059] Take the difference between the reference value of the non-bus-side current and the non-bus-side current I bat as the non-bus-side current error.

[0060] In a possible implementation, determine the compensation control quantity according to the control error adopted in the double closed-loop control and the controller integral of the PI controller, including:

[0061] Input the control error adopted in the double closed-loop control and the controller integral of the PI controller into the preset dynamic controller to obtain the compensation control quantity.

[0062] Among them, the dynamic controller is used to generate a compensation control quantity with negative compensation according to the control error and the controller integral of the PI controller when the control error is less than zero.

[0063] In this embodiment, when the difference between the bus voltage and the given voltage is larger, or the non-bus-side current is higher than the given current (output by the voltage loop), the dynamic controller outputs a larger negative compensation, that is, the faster the bus dynamic control speed.

[0064] In a possible implementation, when the control error is not less than zero, the compensation control quantity output by the dynamic controller is zero. When the control error is less than zero, the compensation control quantity output by the dynamic controller is positively correlated with the absolute values of the control error and the controller integral.

[0065] In this embodiment, when the control error is not less than zero, no compensation is required. When the control error is less than zero, that is, the actual feedback amount of the bus is greater than the given amount of the bus control, the current inner loop integral needs to be reduced to prevent the bus from overvoltage. On this basis, the compensation control amount output by the dynamic controller of the embodiment of the present invention is positively correlated with the "absolute value of the control error and the controller integral". When the control error less than zero deviates from zero, that is, the larger the bus error, the larger the dynamic controller output, and the greater the weakening effect of the current loop integral after the compensation current loop output, that is, the bus overvoltage control can be quickly responded to, and the control effectiveness of the bus voltage can be improved.

[0066] In a possible implementation, the control amount corresponding to the double closed-loop control is compensated based on the compensation control amount to obtain the compensated control amount, including:

[0067] The compensation control amount is superimposed on the corresponding control amount during double closed-loop control to obtain the compensated control amount.

[0068] In this embodiment, other compensation methods besides superposition may also be adopted according to the specific design of the aforementioned dynamic controller, which is not limited here.

[0069] In a possible implementation, controlling the target power conversion circuit according to the compensated control amount includes:

[0070] A modulation wave is generated according to the compensated control quantity, and the modulation wave is sent to the switch tube of the target power conversion circuit to control the bus voltage by controlling the duty cycle of the switch tube.

[0071] In this embodiment, reference may be made to Figure 2 , a PWM modulation wave can be generated based on the compensated control quantity, and the modulation wave can be sent to the development tube of the target power conversion circuit to control the target power conversion circuit by controlling the duty cycle of the switch tube, thereby realizing the control of the bus voltage.

[0072] From the above embodiments, it can be seen that the present invention designs a compensation method that takes into account the control error and the integral of the current inner loop PI controller, so as to avoid as much as possible the bus overvoltage problem caused by the inability of the current controller to de-integrate when the system is unloaded or lightly loaded, thereby improving the dynamic effect of the bus voltage control and ensuring the effectiveness of the bus voltage control.

[0073] On the other hand, the present invention also provides a bus voltage control device 300, including: one or more processors 301, one or more input devices 302, one or more output devices 303, and one or more memories 304. The above-mentioned processors 301, input devices 302, output devices 303, and memories 304 communicate with each other through a communication bus 305. The memory 304 is used to store computer programs, and the computer programs include program instructions. The processor 301 is used to execute the program instructions stored in the memory 304. Among them, the processor 301 is configured to call the program instructions to execute the steps of the above-mentioned method embodiments. It should be understood that in the embodiments of the present invention, the so-called processor 301 may be a central processing unit (CPU). The processor may also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The input device 302 may include a touchpad, a fingerprint sensor (for collecting the fingerprint information and the direction information of the fingerprint) of the user, a microphone, etc., and the output device 303 may include a display (such as an LCD), a speaker, etc. The memory 304 may include a read-only memory and a random access memory, and provide instructions and data to the processor 301. A part of the memory 304 may also include a non-volatile random access memory. For example, the memory 304 may also store information about the device type. In a specific implementation, the processors 301, input devices 302, and output devices 303 described in the embodiments of the present invention may implement the implementation manners described in the first embodiment and the second embodiment of the bus voltage control method provided by the embodiments of the present invention.

[0074] In still another aspect of the present invention, there is also provided a power supply system, including a power conversion circuit and the bus voltage control device described above.

[0075] The above is only the specific implementation manners of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or substitutions within the technical scope disclosed by the present invention, and these modifications or substitutions should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A bus voltage control method, characterized in that, The described bus voltage control method is used to control the corresponding bus voltage by controlling the target power conversion circuit; the bus voltage control method includes: Obtain the bus voltage corresponding to the target power conversion circuit and the non-bus side current, and determine the control quantity corresponding to the double closed-loop control based on the bus voltage and the non-bus side current; Among them, the double closed-loop control is a voltage outer loop-current inner loop control, and the current loop controller adopted by the current inner loop is a PI controller; Determine the compensation control quantity according to the control error adopted during the double closed-loop control and the controller integral of the PI controller; among them, the control error is the bus voltage error or the non-bus side current error; Compensate the control quantity corresponding to the double closed-loop control based on the compensation control quantity to obtain the compensated control quantity, and control the target power conversion circuit according to the compensated control quantity.

2. The bus voltage control method according to claim 1, characterized in that, The determining the control quantity corresponding to the double closed-loop control based on the bus voltage and the non-bus side current includes: Determine the bus voltage error based on the bus voltage and a preset bus voltage reference value; Input the bus voltage error into a preset voltage loop controller to obtain the reference value of the non-bus side current; Determine the non-bus side current error based on the reference value of the non-bus side current and the non-bus side current; Input the non-bus side current error into the PI controller to obtain the control quantity corresponding to the double closed-loop control.

3. The bus voltage control method according to claim 2, characterized in that, The determining the bus voltage error based on the bus voltage and a preset bus voltage reference value includes: Take the difference between the preset bus voltage reference value and the bus voltage as the bus voltage error.

4. The bus voltage control method according to claim 2, wherein The determining the non-bus side current error based on the reference value of the non-bus side current and the non-bus side current includes: Take the difference between the reference value of the non-bus side current and the non-bus side current as the non-bus side current error.

5. The bus voltage control method according to claim 1, wherein, The determining the compensation control quantity according to the control error adopted during the double closed-loop control and the controller integral of the PI controller includes: Input the control error adopted during the double closed-loop control and the controller integral of the PI controller into a preset dynamic controller to obtain the compensation control quantity; Among them, the dynamic controller is used to generate the compensated compensation control quantity with negative compensation according to the control error and the controller integral of the PI controller when the control error is less than zero.

6. The bus voltage control method according to claim 5, wherein When the control error is not less than zero, the compensation control quantity output by the dynamic controller is zero; When the control error is less than zero, the compensation control quantity output by the dynamic controller is positively correlated with the absolute values of the control error and the controller integral.

7. The bus voltage control method according to claim 5, characterized in that The compensating the control quantity corresponding to the double closed-loop control based on the compensation control quantity to obtain the compensated control quantity includes: Superimpose the compensation control quantity on the control quantity corresponding to the double closed-loop control to obtain the compensated control quantity.

8. The bus voltage control method according to any one of claims 1 to 7, characterized in that, The controlling the target power conversion circuit according to the compensated control quantity includes: Generate a modulation wave based on the compensated control quantity, and send the modulation wave to the switching tubes of the target power conversion circuit to control the bus voltage by controlling the duty cycle of the switching tubes.

9. A bus voltage control device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.

10. A power supply system, characterized in that, Comprising: A power conversion circuit and the bus voltage control device according to claim 9.

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