Analog linear compensation circuit, control method and storage medium

Abstract

The present application provides an analog linear compensation circuit, a control method and a storage medium, wherein the analog linear compensation circuit comprises: an amplifier, a negative feedback network, a pole compensation network, a switching switch, a gain network 1 and a gain network 2, wherein a closed-loop controlled sampling feedback signal b(t) is connected to one end of the gain network 1, and the other end of the gain network 1 is connected to the negative input end of the amplifier, and the closed-loop controlled sampling feedback signal b(t) is also connected to one end of the gain network 2, and the other end of the gain network 2 is connected to one end of the switching switch, and the other end of the switching switch is connected to the other end of the gain network 1; the output end of the amplifier is connected to one end of the pole compensation network, and the other end of the pole compensation network is the output end of the analog linear compensation circuit, one end of the negative feedback network is connected to the negative input end of the amplifier, and the other end is connected to the output end of the amplifier, and the positive input end of the amplifier is connected to the control reference network r(t).

Description

Technical Field

[0001] The present invention relates to the field of power electronics and energy storage, and in particular to an analog linear compensation circuit, a control method and a storage medium. Background Art

[0002] In the product development of power electronic power supplies, in order to obtain reliable and stable output voltage or current, it is necessary to perform closed-loop control on the output voltage or current sampling.

[0003] After the existing closed-loop control compensation control circuit parameters are fixed, there is only one set of corresponding closed-loop transfer functions. However, since the main power devices in the power supply system, especially the electrolytic capacitors, their capacitance Cd, equivalent ESR, and equivalent ESL will change with temperature, this will cause the closed-loop control transfer function to not match the application scenario, resulting in poor control performance. Summary of the invention

[0004] The embodiments of the present invention provide an analog linear compensation circuit, a control method and a storage medium, which can effectively solve the problem of poor control performance caused by the mismatch between the transfer function of closed-loop control and the application scenario.

[0005] In a first aspect, an embodiment of the present invention provides an analog linear compensation circuit, the analog linear compensation circuit comprising: an amplifier, a negative feedback network, a pole compensation network, a switching switch, a gain network 1 and a gain network 2, wherein:

[0006] The sampling feedback signal b(t) of the closed-loop control is connected to one end of the gain network 1, and the other end of the gain network 1 is connected to the negative input end of the amplifier. The sampling feedback signal b(t) of the closed-loop control is also connected to one end of the gain network 2, and the other end of the gain network 2 is connected to one end of the switching switch, and the other end of the switching switch is connected to the other end of the gain network 1;

[0007] The output end of the amplifier is connected to one end of the pole compensation network, the other end of the pole compensation network is the output end of the analog linear compensation circuit, one end of the negative feedback network is connected to the negative input end of the amplifier, and the other end is connected to the output end of the amplifier, and the positive input end of the amplifier is connected to the control reference network r(t).

[0008] In a second aspect, a control method for the analog linear compensation circuit provided in the first aspect is provided, the method comprising the following steps:

[0009] Real-time detection of the ambient temperature T0 of the analog linear compensation circuit, and detection of the current output voltage V0 and current I0;

[0010] Whether the loop parameters corresponding to the analog linear compensation circuit match is determined based on the ambient temperature T0, the voltage V0 and the current I0. If they match, the loop parameters are set to parameter B. If they do not match, the loop parameters are set to parameter A.

[0011] According to a third aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program for executing the method steps provided in the second aspect.

[0012] Implementing the embodiments of the present invention has the following beneficial effects:

[0013] The technical solution of the present application, through the linear switching strategy (one circuit, one software control strategy) implemented by the analog compensation circuit and the software control strategy, ensures that each control duty cycle D corresponds to a loop output result, realizes the linear change of the loop output result, solves the problem of poor environmental adaptability of the analog control loop, and thus enables the analog compensation circuit to have a wider range of application scenarios. At the same time, the online switching function of the analog loop compensator is realized, which solves the problem of the need for shutdown switching and improves the adaptability and stability of the analog compensator. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0015] Figure 1 It is a structural diagram of a closed-loop control;

[0016] Figure 2 It is a schematic diagram of the structure of an analog loop compensator;

[0017] Figure 3 A schematic diagram of the structure of an analog linear compensation circuit provided in this application;

[0018] Figure 4 A circuit diagram of an analog linear compensation circuit provided in this application;

[0019] Figure 5 A flow chart of a control method for an analog linear compensation circuit provided in the present application;

[0020] Figure 6 It is a waveform diagram of the Q1 control signal, the compensation circuit output, and the system output voltage provided in this application. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The terms "first", "second", "third" and "fourth" etc. in the specification and claims of the present invention and the drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices.

[0023] Reference to "embodiments" herein means that a particular feature, result, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0024] At present, the generation of new energy generally relies on photovoltaics, wind power, and hydropower, while wind and solar energy generally have problems of strong intermittency and volatility, which will cause instability in the power grid, insufficient electricity during peak hours, and too much electricity during valley hours. Unstable voltage will also cause damage to electricity. Therefore, insufficient electricity demand or insufficient grid acceptance capacity may cause the problem of "abandoning wind and light". To solve these problems, we must rely on energy storage. That is, converting electrical energy into other forms of energy through physical or chemical means and storing it, and converting energy into electrical energy and releasing it when needed. In simple terms, energy storage is similar to a large "power bank". When photovoltaic and wind energy are sufficient, electrical energy is stored and the stored electricity is released when needed.

[0025] Taking electrochemical energy storage as an example, this solution provides an energy storage device, which has a group of chemical batteries in it. The chemical elements in the batteries are mainly used as energy storage media. The charging and discharging process is accompanied by chemical reactions or changes in the energy storage media. Simply put, the electricity generated by wind and solar energy is stored in chemical batteries. When the use of external electricity reaches its peak, the stored electricity is released for use, or transferred to places where electricity is scarce for use.

[0026] See also Figure 1 , Figure 1It is a schematic diagram of the closed-loop control structure. Figure 1 As shown, r(t) is the control reference, b(t) is the sampling feedback signal, and the generated error signal is compensated and finally acts on the controlled object.

[0027] In a closed-loop control system, there are two implementation methods. One is based on digital chip control, that is, digital control, which has the advantages of high control accuracy, strong control flexibility, and adaptive loop switching; the other is based on analog chip implementation, that is, analog control, which has the advantages of low design cost and fast response speed. At the same time, since digital control sampling is periodic sampling, and the sampling signal of analog control has continuity, the real waveform of the sampling signal is better preserved. Therefore, in the current closed-loop system of peak current control, it is necessary to quickly control the peak current, and analog chips are usually used to implement closed-loop control.

[0028] In closed-loop control, in order to make the system have the advantages of fast response speed, high steady-state accuracy and no overshoot, the compensation controller design needs to take the above advantages into consideration. Figure 2 , Figure 2 It is a schematic diagram of the structure of an analog loop compensator.

[0029] See also Figure 3 , Figure 3 A schematic diagram of the structure of an analog linear compensation circuit provided in this application is shown in FIG. Figure 3 As shown, the above analog linear compensation circuit is as follows Figure 3 As shown, it includes: an amplifier, a negative feedback network, a pole compensation network, a switching switch, a gain network 1 (a first gain network) and a gain network 2 (a second gain network), wherein:

[0030] The sampling feedback signal b(t) of the closed-loop control is connected to one end of the gain network 1, and the other end of the gain network 1 is connected to the negative input end of the amplifier. The sampling feedback signal b(t) of the closed-loop control is also connected to one end of the gain network 2, and the other end of the gain network 2 is connected to one end of the switching switch, and the other end of the switching switch is connected to the other end of the gain network 1, and the input end of the switching switch is connected to the switch control signal;

[0031] The output end of the amplifier is connected to one end of the pole compensation network, the other end of the pole compensation network is the output end of the analog linear compensation circuit, one end of the negative feedback network is connected to the negative input end of the amplifier, and the other end is connected to the output end of the amplifier, and the positive input end of the amplifier is connected to the control reference network r(t).

[0032] For example, the gain network 1 or the gain network 2 is a compensation circuit composed of a resistor R and a capacitor C, or a single resistor R; the switching switch is a control switch, such as a MOSFET, an IGBT, a relay, etc. The negative feedback network can be a compensation circuit composed of a resistor R and a capacitor C. The pole compensation network can be a compensation circuit composed of a resistor R and a capacitor C.

[0033] See also Figure 4 , Figure 4 A circuit diagram of an analog linear compensation circuit provided in this application, such as Figure 4 As shown, the switching switch is Q1 (the above Q1 can be a MOS tube or a switch tube), the above gain network 1 can be: a third resistor R3, the gain network 2 can be a first resistor R1, and the above negative feedback network includes: a fourth resistor R4, a second capacitor C2 and a third capacitor C3, wherein the other end of the fourth resistor R4 is connected to one end of the second capacitor C2, the other end of the second capacitor C2 is the other end of the negative feedback network, one end of the fourth resistor R4 is one end of the negative feedback network, and the third capacitor C3 is connected in parallel to the fourth resistor R4 and the second capacitor C2, that is, one end of the third capacitor C3 is connected to one end of the fourth resistor R4, and the other end of the third capacitor C3 is connected to the other end of the second capacitor C2.

[0034] By way of example, the pole compensation network may include: a fifth resistor R5 and a fourth capacitor C4, wherein one end of the fifth resistor R5 is connected to the output end of the amplifier, the other end of the fifth resistor R5 is the output end of the analog linear compensation circuit, one end of the fourth capacitor C4 is connected to the other end of the fifth resistor R5, and the other end of the fourth capacitor C4 is grounded.

[0035] The following Figure 4 The transfer function of the simulated linear compensation circuit shown in the figure is deduced. Here, it is assumed that the on-resistance of switch Q1 is Rq1_on, and the off-resistance is Rq1_off (the resistance of Rq1_off approaches infinity). The two parameters are the inherent parameter characteristics of Q1. The following deduces the series impedance Rz of Q1 and R1 when the control signal of Q1 changes with the duty cycle D:

[0036] When Q1 is turned on,

[0037]

[0038] When Q1 is turned off:

[0039]

[0040] Since the resistance of Rq1_off approaches infinity, I1_off is 0;

[0041] The average current flowing through Q1 is as follows:

[0042]

[0043] According to Rz, Figure 4 The transfer function is as follows:

[0044]

[0045] So after substituting D=0 and D=1, we can get:

[0046] When D=0,

[0047]

[0048] When 0<D<1,

[0049]

[0050] When D=1,

[0051]

[0052] Through the derivation of the above formula, it can be seen that when the duty cycle D gradually changes from 0→0.0001→0.0002→·····→1, each duty cycle can correspond to a loop result, so that the loop output result changes linearly, thereby realizing the function of linear and smooth switching of loop parameters in the analog compensation circuit.

[0053] See also Figure 5 , Figure 5 This is a flow chart of a control method of an analog linear compensation circuit provided in the present application. The specific structure of the analog linear compensation circuit is as follows: Figure 4 As shown, the above method may specifically include the following steps:

[0054] Step S501, real-time detection of the ambient temperature T0 of the analog linear compensation circuit, and detection of the current output voltage V0 and current I0;

[0055] Step S502: judging whether the loop parameters corresponding to the analog linear compensation circuit match according to the ambient temperature T0, the voltage V0 and the current I0; if they match, setting the loop parameters to parameter B; if they do not match, setting the loop parameters to parameter A;

[0056] The above matching determination method may specifically be:

[0057] If T0>5℃, V0×I0>15kW, and the current loop parameter is A, it is determined that there is a mismatch, and the loop parameter is switched from A to B;

[0058] If T0>5℃, V0×I0>15kW, and the current loop parameter is B, the match is confirmed and the loop parameter does not act;

[0059] If it is in other situations (i.e., any one of the conditions T0≤5℃ or V0×I0≤15kW is met), and the current loop parameter is A, the match is determined, and the loop parameter does not act (i.e., does not switch);

[0060] If it is in other situations (that is, any one of the conditions T0≤5℃ or V0×I0≤15kW is met), and the current loop parameter is B, it is determined that there is a mismatch, and the loop parameter is switched from B to A.

[0061] For example, the above method may further include:

[0062] If the loop parameter is switched from parameter A to parameter B, the driving duty cycle D of the switching switch Q1 of the analog linear compensation circuit is controlled to gradually change from 0% to 100%, and the frequency is F. At the same time, in order to ensure that the loop switching process does not oscillate, the step needs to be limited to a%;

[0063] For example, the above method may further include:

[0064] If the loop parameter is switched from parameter B to parameter A, the switching switch Q1 of the analog linear compensation circuit is controlled to drive the duty cycle D to gradually change from 100% to 0%, with a frequency of F. At the same time, in order to ensure that the loop switching process does not oscillate, the step needs to be limited to a%.

[0065] The above-mentioned a can be specifically 0.33, and of course it can also be other values, such as 0.5, 0.66, etc. The above-mentioned frequency F can be specifically 400KHz, and of course in practical applications, it can also be other frequencies, which will not be repeated here.

[0066] The waveforms of the Q1 control signal, compensation circuit output, and system output voltage are shown in the figure below: Figure 6 As shown, Figure 6 It is a waveform diagram of the Q1 control signal, the compensation circuit output, and the system output voltage provided in this application.

[0067] Embodiment 1

[0068] A control method for an analog linear compensation circuit is provided in the first embodiment of the present application. The control signal of the present embodiment is a square wave drive signal, and the square wave has a frequency of f1, and the duty cycle gradually changes from 0% to 100%, with a step of d1. As the duty cycle is gradually released, combined with the following Figure 4 The analog linear compensation circuit shown can make the loop output result change linearly, realizing a linear switching scheme in the analog control loop. The above method includes the following steps:

[0069] Step (1): Power on the power module input;

[0070] Step (2): Initialization setting: Q1 drive signal defaults to D=0, and the loop is set to default parameter A;

[0071] When the duty cycle D of Q1 is 0%, the corresponding loop parameter is A; when the duty cycle of Q1 is 100%, the loop parameter is B; when D is any parameter between 0%-100%, it corresponds to a set of loop parameters between AB; when D changes linearly from 0% to 100%, the loop parameter changes linearly from A to B; the loop parameter is initialized to A;

[0072] The transfer function of the loop is related to the duty cycle as follows:

[0073]

[0074] For example: When D=0.5 / D=0.51, the loop transfer function is as follows;

[0075]

[0076] Step (3): Real-time detection of ambient temperature T0;

[0077] Step (4): Determine whether the power supply is currently in the on state;

[0078] Step (5): When the module is in the power-on state, detect the current output voltage and current;

[0079] Step (6): When the module is not in the power-on state, determine whether T0 matches the current loop parameters. Different applications may have different judgment conditions.

[0080] Step (7): In the power-on state, determine whether T0, V0, and I0 match the current loop parameters. Different applications may have different judgment conditions.

[0081] Step (8): confirm that the loop parameter is switched from A to B according to the judgment condition; of course, the loop parameter can also be switched from B to A.

[0082] Step (9): When the loop parameters need to switch from A to B, Q1 drives the duty cycle D to change gradually from 0% to 100% at a frequency of F. At the same time, in order to ensure that the loop switching process does not oscillate, the step needs to be limited to a%;

[0083] Step (10): When the loop parameters need to be switched from B to A, Q1 drives duty cycle D to change gradually from 100% to 0% at a frequency of F. At the same time, in order to ensure that the loop switching process does not oscillate, the stepping needs to be limited to a%;

[0084] Step (11): Determine whether the input mains power is off;

[0085] Step (12): If power failure is confirmed, the module power failure strategy ends.

[0086] The first embodiment of the present application proposes a linear switching strategy (one circuit, one software control strategy) implemented by an analog compensation circuit and a software control strategy, which ensures that each control duty cycle D corresponds to a loop output result, realizes the linear change of the loop output result, solves the problem of poor environmental adaptability of the analog control loop, and thus enables the analog compensation circuit to have a wider range of application scenarios. At the same time, the online switching function of the analog loop compensator is realized, which solves the problem of the need for shutdown switching and improves the adaptability and stability of the analog compensator.

[0087] The present application also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer-readable storage medium is run on an analog linear compensation circuit, the above method steps are executed.

[0088] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described order of actions, because according to the present invention, certain steps can be received in other orders or performed simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0089] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0090] In the several embodiments provided in the present application, it should be understood that the disclosed device can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of the units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the device or unit can be electrical or other forms.

[0091] Those skilled in the art will appreciate that all or part of the steps in the various methods of the above embodiments may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable memory, which may include a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0092] The embodiments of the present invention are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An analog linear compensation circuit, characterized in that: The analog linear compensation circuit includes: an amplifier, a negative feedback network, a pole compensation network, a switching switch, a first gain network and a second gain network, wherein: The sampling feedback signal b(t) of the closed-loop control is connected to one end of the first gain network, the other end of the first gain network is connected to the negative input end of the amplifier, the sampling feedback signal b(t) of the closed-loop control is also connected to one end of the second gain network, the other end of the second gain network is connected to one end of the switching switch, and the other end of the switching switch is connected to the other end of the first gain network; The output end of the amplifier is connected to one end of the pole compensation network, the other end of the pole compensation network is the output end of the analog linear compensation circuit, one end of the negative feedback network is connected to the negative input end of the amplifier, and the other end is connected to the output end of the amplifier, and the positive input end of the amplifier is connected to the control reference network r(t); The first gain network or the second gain network is a compensation circuit composed of a resistor and a capacitor; Or the first gain network or the second gain network is: a resistor; The negative feedback network is: a compensation circuit composed of a resistor and a capacitor; The pole compensation network is: a compensation circuit composed of a resistor and a capacitor; The negative feedback network includes: a fourth resistor R4, a second capacitor C2 and a third capacitor C3, wherein the other end of the fourth resistor R4 is connected to one end of the second capacitor C2, the other end of the second capacitor C2 is the other end of the negative feedback network, one end of the fourth resistor R4 is one end of the negative feedback network, the third capacitor C3 is connected in parallel to the fourth resistor R4 and the second capacitor C2, and the fourth resistor R4 is connected in series with the second capacitor C2; The pole compensation network includes: a fifth resistor R5 and a fourth capacitor C4, wherein one end of the fifth resistor R5 is connected to the output end of the amplifier, the other end of the fifth resistor R5 is the output end of the analog linear compensation circuit, one end of the fourth capacitor C4 is connected to the other end of the fifth resistor R5, and the other end of the fourth capacitor C4 is grounded.

2. The analog linear compensation circuit according to claim 1, characterized in that: The first gain network is the third resistor R3, and the second gain network is the first resistor R1.

3. A control method for an analog linear compensation circuit as claimed in any one of claims 1 to 2, characterized in that: The method comprises the following steps: Real-time detection of the ambient temperature T0 of the analog linear compensation circuit, and detection of the current output voltage V0 and current I0; According to the ambient temperature T0, the voltage V0 and the current I0, it is judged whether the loop parameters corresponding to the analog linear compensation circuit match. If they match, the loop parameters are set to parameter B. If they do not match, the loop parameters are set to parameter A. The step of judging whether the loop parameters corresponding to the analog linear compensation circuit match according to the ambient temperature T0, the voltage V0 and the current I0 specifically includes: If T0>5℃ and V0×I0>15W, it is determined to be matched and the loop parameter is set to B. Otherwise, it is determined to be unmatched; If T0>10℃ and V0×I0>20W, it is determined to be matched and the loop parameter is set to B. Otherwise, it is determined to be mismatched.

4. The control method according to claim 3, characterized in that: The method further comprises: If the loop parameter switches from parameter A to parameter B, the driving duty cycle D of the switching switch Q1 controlling the analog linear compensation circuit changes gradually from 0% to 100%, the frequency is F, and the step of the gradual change needs to be limited to a%; the a% is the step limit value.

5. The control method according to claim 3, characterized in that: The method further comprises: If the loop parameter switches from parameter B to parameter A, the switching switch Q1 controlling the analog linear compensation circuit drives the duty cycle D to gradually change from 100% to 0%, the frequency is F, and the step of the gradual change needs to be limited to a%; the a% is the step limit value.

6. A computer-readable storage medium, wherein a computer program is stored in the computer-readable storage medium, wherein the computer program is used to execute the method steps according to claims 3 to 5.

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