A micro-current compensation method and system for precision control

Abstract

The present invention relates to the field of precision electrical signal control technology, and is a micro-current compensation method and system for precision control, comprising: S1, connecting an auxiliary power supply in parallel to a main power supply circuit to form a main current control output branch and an auxiliary current output branch, and the main current control output branch and the auxiliary current output branch are connected in parallel and then output to a target object; S2, controlling the main current control output branch to output the main current to the target object according to a preset current size, and performing corresponding compensation according to the error of the main current control output branch, and controlling the auxiliary current output branch, so that the error between the current output after the main current control output branch and the auxiliary current output branch are connected in parallel and the preset current size is within a preset range, and this scheme fundamentally improves the control granularity of the battery testing equipment, thereby solving the control accuracy problem. Especially for battery testing instruments, it is possible to achieve a battery testing instrument with an accuracy of 0.02% / 0.01% or even higher.

Description

Technical Field

[0001] The present invention relates to the technical field of precision electrical signal control, and in particular to a micro-current compensation method and system for precision control. Background Art

[0002] Switching power supply technology has very good energy efficiency, and the market is developing very rapidly. In switching power supplies, especially in the battery testing industry, basically all products are used for the development of digital switching power supply technology; the manufacturers who do well in this field will use HRPWM (high-resolution pulse width controller); due to the limitations of HRPWM itself, the equipment can achieve 0.05%, which is very good. If we further pursue 0.02%, the control granularity cannot meet the demand.

[0003] At present, high-precision battery testing instruments are mainly based on linear power supplies, such as the existing M340A G340A, foreign MACCOR M4200 series and other equipment, all of which are linear power supplies with an accuracy of 0.02% or 0.01%; the mainstream switching power supply battery testing equipment is Blue Power BTS5000 / 6000 series, Xinwei ES series, MACCOR S4000 series, etc., with an accuracy of 0.05%; even higher-precision switching power supply equipment is limited by several unique problems of switching power supplies and has never appeared.

[0004] The mainstream switching frequency of battery testing equipment is around 150K, which results in a control granularity of HRPWM of only 0.003%. It is basically unrealistic to achieve a control accuracy of 0.02% with this control granularity, because the occasional nonlinearity of some devices will cause problems with control accuracy. Summary of the invention

[0005] The present invention provides a micro-current compensation method and system for precise control, which solves the technical problem of limited accuracy of the above-mentioned battery testing instrument.

[0006] In order to solve the above technical problems, the present invention provides a micro-current compensation method for precise control, comprising:

[0007] S1, connecting an auxiliary power supply in parallel to a main power supply loop to form a main current control output branch and an auxiliary current output branch, wherein the main current control output branch and the auxiliary current output branch are connected in parallel and then output to a target object;

[0008] S2, controls the main current control output branch to output the main current to the target object according to the preset current size, and performs corresponding compensation according to the error of the main current control output branch, and controls the auxiliary current output branch so that the error between the output current of the main current control output branch and the auxiliary current output branch in parallel and the preset current size is within a preset range.

[0009] Optionally, before S1, it also includes: charging the target object separately through the main current control output branch formed by the original main power supply circuit according to the current required by the target object, so as to test and obtain the effective control granularity of the main current control output branch formed by the original main power supply circuit.

[0010] Optionally, the comprehensive control granularity % after the main current control output branch is connected in parallel with the auxiliary current output branch = the control granularity % of the auxiliary current output branch * the range of the main current control output branch / the range of the auxiliary current output branch.

[0011] Optionally, the main current control output branch includes a main power supply X, and the auxiliary current output branch includes an auxiliary power supply M. The main power supply X and the auxiliary power supply M are connected in parallel and then output to a battery for charging.

[0012] Optionally, the S2 specifically includes: when the target object is a battery, the battery charging voltage is 2V, and the charging current is 60A;

[0013] If the main power supply X outputs 59.98A and the auxiliary power supply M outputs 0.02A, the combined output is exactly 60A;

[0014] If the main power supply X outputs 60.01A and the auxiliary power supply M outputs -0.01A, the combined output is still an accurate 60A.

[0015] Optionally, when the output of the main power supply X is within the range of 59.98A to 60.01A, feedback regulation adjusts the output of the auxiliary power supply M so that the output is accurately 60A after being combined.

[0016] Optionally, the auxiliary current output branch is an output circuit formed by the operation amplifier chip output circuit or a small current circuit in cooperation with the DA of the single-chip microcomputer itself.

[0017] Optionally, when the auxiliary current output branch is a circuit that can only input current, the output current of the main current control output branch is always greater than the preset current, and the auxiliary current output branch absorbs the excess current;

[0018] When the auxiliary current output branch is a circuit that can only output current, the auxiliary current output branch compensates for the insufficient current;

[0019] When the auxiliary current output branch is an output input current circuit, the auxiliary current output branch processes the current of the remaining part of the main current control output branch.

[0020] The present invention also provides a system for implementing a microcurrent compensation method for precision control, the system comprising a main current control output branch and an auxiliary current output branch, the main current control output branch being used to output electrical energy to a target object according to a preset current size, the auxiliary current output branch being used to perform corresponding compensation according to the error of the main current control output branch, so that the error between the current output after the main current control output branch and the auxiliary current output branch are connected in parallel and the preset current size is within a preset range.

[0021] An embodiment of the present invention provides a system for implementing a micro-current compensation method for precision control, the system comprising a main current control output branch and an auxiliary current output branch, the main current control output branch being used to output electrical energy to a target object according to a preset current magnitude, the auxiliary current output branch being used to perform corresponding compensation according to the error of the main current control output branch, so that the error between the current output after the main current control output branch and the auxiliary current output branch are connected in parallel and the preset current magnitude is within a preset range.

[0022] Beneficial effect: The present invention provides a micro-current compensation method and system for precision control, including: S1, connecting an auxiliary power supply in parallel to the main power supply circuit to form a main current control output branch and an auxiliary current output branch, and the main current control output branch and the auxiliary current output branch are connected in parallel and then output to the target object; S2, controlling the main current control output branch to output the main current to the target object according to the preset current size, and making corresponding compensation according to the error of the main current control output branch, and controlling the auxiliary current output branch, so that the error between the current output after the main current control output branch and the auxiliary current output branch are connected in parallel and the preset current size is within a preset range, and this scheme fundamentally improves the control granularity of the battery testing equipment, thereby solving the control accuracy problem. Especially for battery testing instruments, it is possible to achieve a battery testing instrument with an accuracy of 0.02% / 0.01% or even higher.

[0023] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. The specific implementation of the present invention is given in detail by the following embodiments and their accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 It is a flow chart of the micro-current compensation method for precise control of the present invention;

[0026] Figure 2 This is a functional module schematic diagram of the micro-current compensation method and system for precise control of the present invention. DETAILED DESCRIPTION

[0027] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention. The present invention is described in more detail by way of example with reference to the accompanying drawings in the following paragraphs. The advantages and features of the present invention will become clearer according to the following description and claims. It should be noted that the drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0028] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a component centered. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a component centered. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a component centered. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0030] like Figure 1 and Figure 2 As shown, the present invention provides a micro-current compensation method for precise control, comprising:

[0031] S1, connecting an auxiliary power supply in parallel to a main power supply loop to form a main current control output branch and an auxiliary current output branch, wherein the main current control output branch and the auxiliary current output branch are connected in parallel and then output to a target object;

[0032] S2, controls the main current control output branch to output the main current to the target object according to the preset current size, and performs corresponding compensation according to the error of the main current control output branch, and controls the auxiliary current output branch so that the error between the output current of the main current control output branch and the auxiliary current output branch in parallel and the preset current size is within a preset range.

[0033] This technical solution provides a feasible basis for high-precision electrical signal control; as far as the battery testing instruments in this industry are concerned, this can be used to achieve 0.02% / 0.01% or even higher accuracy battery testing instruments; because the realization of high-precision battery testing instruments or power supplies, electronic loads, etc. is not only a high control granularity problem but also many other problems need to be solved; therefore, this technical solution is only a direction point for solving the big problem of high-precision electrical signals.

[0034] In an optional solution, the main current control output branch includes a main power supply X, and the auxiliary current output branch includes an auxiliary power supply M. The main power supply X and the auxiliary power supply M are connected in parallel and then output to the battery for charging.

[0035] The method specifically refers to connecting an auxiliary power supply M, which is a small part of the main power supply X, in parallel with the main power supply circuit. It can be output / input or a complete four-quadrant power supply. In this way, a power supply with high control granularity at the same level as the main power supply is realized through two power supplies with low control granularity requirements.

[0036] For example, when designing a 100A precision battery tester, taking a switching frequency of 200K as an example, the HRPWM control granularity itself is 0.004%, discarding a part of the first and last range margins, and discarding one control granularity due to device nonlinearity; the final effective control granularity is approximately at the 0.01% level.

[0037] Therefore, the full scale of the auxiliary power supply M is designed to be 0.02% (this ratio) of 100A, or 20mA; this current is very small, and can be directly output using a general-purpose op amp chip (the op amp itself is a four-quadrant voltage, but its driving capability is very weak) or a simple low-current circuit, combined with a microcontroller's own DA output control granularity. Currently, the microcontrollers' built-in DAs are basically above 12 bits, and the control granularity can be easily increased by three orders of magnitude; depending on the needs of different industries, an increase of two orders of magnitude is generally sufficient.

[0038] The calculation method of comprehensive control granularity after the main power supply X is connected in parallel with the auxiliary power supply M is % = control granularity of the auxiliary current output branch % * the range of the main current control output branch / the range of the auxiliary current output branch = 20mA% * 0.001 / 100A = 0.00002%. In this way, a digital switching power supply product with high control granularity can be realized at a very low cost.

[0039] Take the 100A battery tester as an example:

[0040] For example, when charging a battery, the battery voltage is 2V and the current setting is 60A; then the possible duty cycle of the switching power supply is about 2V*60A / (5V*100A)=24%. The switching power supply power model is not an accurate model and is only used for qualitative description.

[0041] Due to the insufficient control granularity of the main power supply, the actual current may be 59.980A at the previous control point, and 60.01A at the next control point, so it is impossible to accurately output 60A.

[0042] There are two ways to deal with this:

[0043] The main power supply X outputs 59.98A, the auxiliary power supply M outputs 0.02A, and the combined output is exactly 60A; or, the main power supply X outputs 60.01A, the auxiliary power supply M outputs -0.01A, and the combined output is still exactly 60A;

[0044] Of course, similarly, when the output of the main power supply X is within the range of 59.98A to 60.01A, the feedback regulation adjusts the output of the auxiliary power supply M so that the output is accurately 60A after being combined.

[0045] The specific control principle of the embodiment of the present invention is as follows:

[0046] First, based on the application scenario, a model device is produced according to the existing design plan to test its effective control granularity.

[0047] Second, design the auxiliary compensation circuit of the micro-current according to its effective control granularity; there are three schemes for this circuit design;

[0048] a. The auxiliary compensation circuit can only input current (it is recommended that the auxiliary current full scale is twice the main power supply control granularity);

[0049] b. The auxiliary compensation circuit can only output current (it is recommended that the auxiliary current full scale is twice the main power supply control granularity);

[0050] c. The auxiliary compensation circuit can input and output current (it is recommended that the full scale of the auxiliary current be the granularity of the main power supply control);

[0051] Third, the use of the control process also corresponds to three types due to the three schemes

[0052] a. Since the auxiliary circuit can only input current, the output of the main power supply is always greater than the set current, and the auxiliary circuit absorbs the excess current;

[0053] b. Since the auxiliary circuit can only output current, the output of the main power supply is always less than the set current, and the insufficient current is compensated by the auxiliary circuit;

[0054] c. Since the auxiliary circuit can output the input current, the output of the main power supply is very flexible. It can be greater or less than the set current, and the auxiliary circuit will handle the remaining current. Of course, if the main power supply outputs a current with an absolute value closer to the set value, it will be better for overall control.

[0055] like Figure 2 As shown, an embodiment of the present invention also provides a system for implementing a micro-current compensation method for precision control, the system comprising a main current control output branch and an auxiliary current output branch, the main current control output branch being used to output electrical energy to a target object according to a preset current size, the auxiliary current output branch being used to perform corresponding compensation according to the error of the main current control output branch, so that the error between the current output after the main current control output branch and the auxiliary current output branch are connected in parallel and the preset current size is within a preset range.

[0056] The embodiments of the present invention provide a feasible basis for high-precision electrical signal control; as far as the battery testing instruments in this industry are concerned, it is possible to achieve 0.02% / 0.01% or even higher accuracy battery testing instruments; since the realization of high-precision battery testing instruments or power supplies, electronic loads, etc. is not only a high control granularity problem but also many other problems need to be solved; therefore, this technology is only a direction point for solving the big problem of high-precision electrical signals.

[0057] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0058] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0059] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0060] 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 above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A micro-current compensation method for precision control, characterized in that: include: S1, connecting an auxiliary power supply in parallel to the main power supply loop to form a main current control output branch and an auxiliary current output branch, the main current control output branch and the auxiliary current output branch are connected in parallel and output to the target object; the main current control output branch includes a main power supply X, the auxiliary current output branch includes an auxiliary power supply M, the main power supply X and the auxiliary power supply M are connected in parallel and output to the battery for charging, and the auxiliary power supply M is an output or input or a complete four-quadrant power supply; S2, controlling the main current control output branch to output the main current to the target object according to the preset current size, and performing corresponding compensation according to the error of the main current control output branch, and controlling the auxiliary current output branch, so that the error between the current output by the main current control output branch and the auxiliary current output branch after being connected in parallel and the preset current size is within a preset range; Among them, through two power supplies with low control granularity requirements, a power supply with high control granularity at the level of the main power supply is realized: the comprehensive control granularity % after the main current control output branch is connected in parallel with the auxiliary current output branch = the control granularity % of the auxiliary current output branch * the range of the auxiliary current output branch / the range of the main current control output branch; the full scale of the auxiliary power supply is designed to be 20mA, 0.02% of 100A, and a general-purpose operational amplifier chip or a small current circuit output is used, and the DA output control granularity of a single-chip microcomputer is matched. The DA of the single-chip microcomputer is more than 12 bits, which improves the control granularity by 3 orders of magnitude and achieves a high precision of 0.02% or 0.01%; Among them, there are three schemes in the design of auxiliary compensation circuit: the auxiliary compensation circuit can only input current, and the full scale of auxiliary current is twice the control granularity of the main power supply; the auxiliary compensation circuit can only output current, and the full scale of auxiliary current is twice the control granularity of the main power supply; the auxiliary compensation circuit can input and output current, and the full scale of auxiliary current is the control granularity of the main power supply; When the auxiliary current output branch is a current-only circuit, the output current of the main current control output branch is always greater than the preset current, and the auxiliary current output branch absorbs the excess current. When the auxiliary current output branch is a circuit that can only output current, the auxiliary current output branch compensates for the insufficient current; When the auxiliary current output branch is an output input current circuit, the auxiliary current output branch processes the current of the remaining part of the main current control output branch; Before S1, it also includes: charging or discharging or charging and discharging the target object separately according to the current required by the target object through the main current control output branch formed by the original main power supply circuit, so as to test and obtain the effective control granularity of the main current control output branch formed by the original main power supply circuit.

2. The micro-current compensation method for precision control according to claim 1, characterized in that: The S2 specifically includes: when the target object is a battery, the battery charging voltage is 2V, and the charging current is 60A; If the main power supply X outputs 59.98A and the auxiliary power supply M outputs 0.02A, the combined output is exactly 60A; If the main power supply X outputs 60.01A and the auxiliary power supply M outputs -0.01A, the combined output is still an accurate 60A.

3. The micro-current compensation method for precision control according to claim 2, characterized in that: When the output of the main power supply X is within the range of 59.98A to 60.01A, feedback regulation adjusts the output of the auxiliary power supply M so that the output is accurately 60A after merging.

4. The micro-current compensation method for precise control according to claim 1, characterized in that: The auxiliary current output branch is an output circuit formed by the cooperation of an operational amplifier chip output circuit or a small current circuit and a DA of the single-chip microcomputer itself.

5. A system for implementing the micro-current compensation method for precise control as claimed in any one of claims 1 to 4, characterized in that: The system includes a main current control output branch and an auxiliary current output branch. The main current control output branch is used to output electric energy to a target object according to a preset current size, and the auxiliary current output branch is used to perform corresponding compensation according to the error of the main current control output branch, so that the error between the current output after the main current control output branch and the auxiliary current output branch are connected in parallel and the preset current size is within a preset range.

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