Multi-loop control method, device and system, storage medium and controller

Abstract

The invention discloses a multi-loop control method, device and system, a storage medium, a controller and a photovoltaic energy storage device.Multiple loops are arranged in parallel, each loop at least comprises an integrator, and the control method comprises the steps that the output value of each loop in the current control period is obtained; determining a target loop from the plurality of loops according to the output value; the integral value output by the integrator of the first loop is forced to be equal to the integral value output by the integrator of the target loop so as to be used for calculating the output value of the next control period of the first loop, and the first loop is the loop except the target loop in the multiple loops. According to the control method, by forcibly enabling the integral value output by the integrator of the first loop to be equal to the integral value output by the integrator of the target loop, the problem of overshoot oscillation during loop switching can be solved, and smooth switching of the loops is achieved.

Description

Technical Field

[0001] The present invention relates to the field of electrical control, and in particular to a multi-loop control method, device, system, storage medium, controller, and photovoltaic energy storage device. Background Art

[0002] In electrical control, such as PCS (Power Conversion System) power supply PWM (Pulse Width Modulation) control, there are many requirements for non-single-loop parallel control. For example, parallel control of the power loop, voltage loop, and current loop requires three loops. At any given moment, the calculation result of only one loop is used as the parallel control output, and loop switching is performed in critical situations. This parallel control algorithm design can meet the various control requirements of our products.

[0003] Currently, in the aforementioned parallel control, each parallel loop performs synchronous calculations. When one of the loops outputs a result for a long time, the calculation results of the other parallel loops will be in a limited state of integral saturation. This will cause the output of the loop after switching to differ significantly from the target value, which may cause overshoot oscillations and affect the stability of control. Summary of the Invention

[0004] The present invention aims to address, at least to some extent, one of the technical problems in the related art. To this end, the present invention provides a multi-loop control method, apparatus, system, storage medium, controller, and photovoltaic energy storage device to address overshoot oscillation during loop switching and achieve smooth loop switching.

[0005] In a first aspect, an embodiment of the present invention proposes a multi-loop control method, in which multiple loops are arranged in parallel, and each of the loops includes at least an integrator. The control method includes: obtaining the output value of each of the loops in the current control cycle; determining a target loop from the multiple loops based on the output value; forcing the integral value output by the integrator of the first loop to be equal to the integral value output by the integrator of the target loop, for use in calculating the output value of the first loop in the next control cycle, wherein the first loop is a loop among the multiple loops other than the target loop.

[0006] In addition, the multi-loop control method of the embodiment of the present invention may also have the following additional technical features:

[0007] According to one embodiment of the present invention, obtaining the output values ​​of the multiple loops in the current control cycle includes: for each of the loops, obtaining the target reference value and actual control value of the loop input in the current control cycle, and calculating the difference between the target reference value and the actual control value, and obtaining the output value of the loop based on the difference and the integral value output by the integrator of the loop.

[0008] According to an embodiment of the present invention, determining a target loop from the multiple loops according to the output values ​​includes: using a loop corresponding to a minimum output value as the target loop; or using a loop corresponding to a maximum output value as the target loop.

[0009] According to one embodiment of the present invention, before determining the target loop from the multiple loops based on the output value, the control method also includes: if the output value is greater than a preset maximum limit value, forcing the output value to be equal to the preset maximum limit value; and / or, if the output value is less than a preset minimum limit value, forcing the output value to be equal to the preset minimum limit value.

[0010] According to one embodiment of the present invention, the control method is applied to a photovoltaic energy storage device, and the control method further includes: controlling the photovoltaic energy storage device in the current control cycle using the output value of the target loop.

[0011] According to one embodiment of the present invention, the loop further includes a proportional device and / or a differentiator.

[0012] In a second aspect, an embodiment of the present invention proposes a multi-loop control device, in which multiple loops are arranged in parallel, and each of the loops includes at least an integrator. The control device includes: an acquisition module for acquiring the output values ​​of each of the loops in the current control cycle; a determination module for determining a target loop from the multiple loops based on the output values; and a control module for forcing the integral value output by the integrator of the first loop to be equal to the integral value output by the integrator of the target loop, for use in calculating the output value of the first loop in the next control cycle, wherein the first loop is a loop among the multiple loops other than the target loop.

[0013] In a third aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the multi-loop control method described in the embodiment of the first aspect is implemented.

[0014] In a fourth aspect, an embodiment of the present invention proposes a controller comprising a memory, a processor, and a computer program stored in the memory. When the computer program is executed by the processor, the multi-loop control method described in the embodiment of the first aspect is implemented.

[0015] In the fifth aspect, an embodiment of the present invention proposes a multi-loop control system, comprising: multiple loops, the multiple loops are arranged in parallel, and each of the loops includes at least an integrator; the multi-loop control device described in the embodiment of the second aspect above, or the controller described in the embodiment of the fourth aspect above.

[0016] In the sixth aspect, an embodiment of the present invention proposes a photovoltaic energy storage device, including: the multi-loop control system described in the embodiment of the fifth aspect above, wherein the multiple loops in the multi-loop control system include an input photovoltaic voltage loop, an input photovoltaic power loop and an output bus voltage loop.

[0017] In addition, the photovoltaic energy storage device according to the embodiment of the present invention may also have the following additional technical features:

[0018] According to one embodiment of the present invention, the photovoltaic energy storage device further includes: an input photovoltaic current loop, a photovoltaic panel, and a voltage converter, wherein the input end of the voltage converter is connected to the photovoltaic panel, and the output end of the voltage converter is used to connect to a load; wherein, when one of the input photovoltaic voltage loop, the input photovoltaic power loop, and the output bus voltage loop is a target loop, the output value of the target loop serves as the target reference value of the input photovoltaic current loop, so as to perform PWM control on the voltage converter through the input photovoltaic current loop.

[0019] The multi-loop control method, apparatus, system, storage medium, controller, and photovoltaic energy storage device of the embodiments of the present invention address multiple loops arranged in parallel and including at least an integrator. After determining a target loop based on the loop output values, the integrated values ​​of the integrator outputs of loops other than the target loop are forced to be equal to the integrated value of the integrator output of the target loop. This is used to calculate the output values ​​of the loops other than the target loop in the next control cycle. This solves the problem of overshoot oscillation during loop switching and achieves smooth loop switching.

[0020] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a flow chart of a multi-loop control method according to an embodiment of the present invention;

[0022] Figure 2 is a schematic structural diagram of a photovoltaic energy storage device according to an embodiment of the present invention;

[0023] Figure 3 is a schematic diagram of the control structure of a photovoltaic energy storage device according to an embodiment of the present invention;

[0024] Figure 4is a structural block diagram of a controller according to an embodiment of the present invention;

[0025] Figure 5 is a structural block diagram of a multi-loop control device according to an embodiment of the present invention;

[0026] Figure 6 is a structural block diagram of a multi-loop control system according to an embodiment of the present invention;

[0027] Figure 7 It is a structural block diagram of a photovoltaic energy storage device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0029] The following describes the multi-loop control method, device, system, storage medium, controller, and photovoltaic energy storage device according to embodiments of the present invention with reference to the accompanying drawings.

[0030] In an embodiment of the present invention, multiple loops (e.g., two, three, or more, the specific number of which may be determined based on system requirements) are provided in parallel, and each loop includes at least an integrator. Optionally, the loop may also include a proportional and / or a differentiator. For example, the loop may be a PI loop, a PID loop, or the like.

[0031] Figure 1 is a flow chart of a multi-loop control method according to an embodiment of the present invention.

[0032] like Figure 1 As shown, the multi-loop control method includes:

[0033] S11, obtaining the output value of each loop in the current control cycle.

[0034] In some embodiments of the present invention, the output values ​​of the multiple loops in the current control cycle are obtained, including: for each loop, obtaining the target reference value and actual control value of the loop input in the current control cycle, and calculating the difference between the target reference value and the actual control value, and obtaining the output value of the loop based on the difference and the integral value output by the integrator of the loop.

[0035] Specifically, the target reference value can be a pre-set fixed value, which can be determined according to the working conditions of the device to which the multi-loop is applied; the actual control value is the actual collected value during the operation of the device to which the multi-loop is applied, which can be obtained through corresponding sensors, acquisition circuits, etc. When controlling the device to which the multi-loop is applied, the target reference value and the actual control value of each loop can be used as the input of the corresponding loop controller (such as a PI controller). The controller calculates the difference between the target reference value and the actual control value, and obtains the corresponding output value based on the difference and the integral value output by the integrator of the loop. Among them, the integral value output by the integrator of the loop can be calculated based on the difference, or it can be forcibly assigned in the previous control cycle; one of the output values ​​of the multiple loops is used for subsequent control, for example, directly used for PWM control, or for example, PWM control is performed through a subsequent loop.

[0036] S12, determining a target loop from multiple loops according to the output value.

[0037] Specifically, the target loop is the loop that obtains control rights for the next control cycle of the device to which the multiple loops are applied. The method for determining the target loop based on the output value can be determined based on each loop and its configuration in the device to which it is applied. For example, in some embodiments of the present invention, determining the target loop from the multiple loops based on the output value includes: selecting the loop corresponding to the minimum output value as the target loop. For another example, in other embodiments of the present invention, determining the target loop from the multiple loops based on the output value includes: selecting the loop corresponding to the maximum output value as the target loop.

[0038] In some embodiments of the present invention, after the target loop is determined, the output value of the target loop may be used to control the devices applied to the multiple loops in the current control cycle.

[0039] Specifically, at the start of control, the output values ​​of multiple loops in the first control cycle can be obtained, from which the first target loop is determined. The output value of the first target loop is then used to control the devices applied to the multiple loops for the first control cycle. Subsequently, the output values ​​of multiple loops in the second control cycle are obtained, from which the second target loop is determined. The output value of the second target loop is then used to control the devices applied to the multiple loops for the second control cycle, and so on. The control cycle can be longer than the output value calculation cycle of each loop, and the devices applied to the multiple loops can include photovoltaic energy storage devices.

[0040] It should be noted that, during the process of obtaining the output values ​​of multiple loops in the first control cycle and determining the first target loop therefrom, no loop is controlled. During the process of obtaining the output values ​​of multiple loops in the nth control cycle and determining the nth target loop therefrom, the output value of the (n-1)th target loop is still used to control the devices applied to the multiple loops, where n is greater than or equal to 2.

[0041] S13, forcing the integrated value output by the integrator of the first loop to be equal to the integrated value output by the integrator of the target loop, so as to be used for calculating the output value of the first loop in the next control cycle, wherein the first loop is a loop among the multiple loops excluding the target loop.

[0042] Specifically, the integrator in the loop is used to eliminate the time-varying and uncertain nature of the system. By continuously integrating and accumulating errors to adjust the control variable, system stability and accuracy can be achieved. To this end, after determining the target loop, the integral value output by the integrator of the first loop is forced to be equal to the integral value output by the integrator of the target loop, which is used to calculate the output value of the first loop in the next control cycle. As a result, when the target loop in the current control cycle is different from the target loop in the previous control cycle, and regardless of which loop is the target loop, the actual control variable of the target loop in the current control cycle no longer continuously changes in the direction of the previous control cycle (including the previous control cycle), and the output values ​​of the target loops in two adjacent control cycles are similar, thereby reducing loop overshoot and achieving smooth loop switching.

[0043] In some embodiments of the present invention, before determining the target loop from multiple loops based on the output value, the control method also includes: if the output value is greater than a preset maximum limit value, forcing the output value to be equal to the preset maximum limit value; and / or, if the output value is less than a preset minimum limit value, forcing the output value to be equal to the preset minimum limit value.

[0044] In this embodiment, the integral value of the loop can also be limited between a preset minimum limit value and a preset maximum limit value, that is, when the integral value is greater than the preset maximum limit value, it is limited to the preset maximum limit value; when the integral value is less than the preset minimum limit value, it is limited to the preset minimum limit value. The preset minimum limit value and the preset maximum limit value of different loops can be the same or different, and the specific values ​​can be set as needed. The range defined by the preset minimum limit value and the preset maximum limit value can be smaller than the range defined when the integrator is saturated. Assuming that the preset minimum limit value is min and the preset maximum limit value is max, min<max, if the value of the integrator of a certain loop when saturated is a smaller value min', and the value of the integrator of another loop when saturated is a larger value max', then min is greater than min' and max is less than max'. This can reduce overshoot oscillation to a certain extent.

[0045] The following describes the multi-loop control method of an embodiment of the present invention by taking the control method applied to a photovoltaic energy storage device as an example:

[0046] The multiple loops include an input photovoltaic voltage loop, an input photovoltaic power loop, and an output bus voltage loop. When the target loop is the input photovoltaic voltage loop, the input photovoltaic voltage loop is used to control the current control cycle. The integrated value output by the input photovoltaic power loop integrator and the integrated value output by the output bus voltage loop integrator are forced to be equal to the integrated value output by the input photovoltaic voltage loop integrator. This is used to calculate the output values ​​of the input photovoltaic power loop and the output bus voltage loop in the next control cycle.

[0047] In this example, if Figure 2 As shown, the photovoltaic energy storage device includes a photovoltaic panel and a DC / DC converter, wherein the DC / DC converter is used to convert the voltage of the photovoltaic panel to provide the required voltage for the load. The DC / DC converter may include a switch tube, which can perform PWM control on the DC / DC converter to achieve the conversion of the photovoltaic panel voltage. Figure 3 As shown, the control loops involved in the photovoltaic energy storage device may include an input photovoltaic voltage loop, an input photovoltaic power loop, an output bus voltage loop, and an input photovoltaic current loop. The above-mentioned multiple loops include an input photovoltaic voltage loop, an input photovoltaic power loop, and an output bus voltage loop. The three are arranged in parallel, and a target reference current Ipv_ref is provided for the input photovoltaic current loop through a control device.

[0048] See also Figure 2 、 Figure 3 , the input photovoltaic voltage error Vpv_error=Vpv_ref-Vpv, as the input of the input photovoltaic voltage loop controller, the output of the input photovoltaic voltage loop is OUT_Vpv; the input photovoltaic power error Ppv_error=Ppv_ref-Ppv, as the input of the input photovoltaic power loop controller, the output of the input photovoltaic power loop is OUT_Ppv; the output bus voltage error Vbus_error=Vbus_ref-Vbus, as the input of the output bus voltage loop controller, the output of the output bus voltage loop is OUT_Vbus. Among them, Ppv = Ipv * Vpv, Ipv represents the actual input photovoltaic current, which together with Ipv_ref serves as the input of the input photovoltaic current loop; Vpv and Vpv_ref represent the actual input photovoltaic voltage and the target input photovoltaic voltage, respectively, which serve as the actual control value and the target reference value of the input photovoltaic voltage loop, respectively; Ppv and Ppv_ref represent the actual input photovoltaic power and the target input photovoltaic power, respectively, which serve as the actual control value and the target reference value of the input photovoltaic power loop, respectively; Vbus and Vbus_ref represent the actual output bus voltage and the target output bus voltage, respectively, which serve as the actual control value and the target reference value of the output bus voltage loop, respectively.

[0049] Taking the example of the input photovoltaic voltage loop, the input photovoltaic power loop and the output bus voltage loop all adopting proportional integral PI (ie including an integrator and a proportional device) control, the input photovoltaic current loop can also adopt PI control.

[0050] For the input photovoltaic voltage loop, the following equation exists:

[0051] Vpv_sum+=Ki_vpv*Vpv_error;

[0052] Out_Vpv=Vpv_sum+Kp_vpv*Vpv_error;

[0053] If Vpv_sum>max, then Vpv_sum=max;

[0054] If Out_Vpv>max, then Out_Vpv=max;

[0055] If Vpv_sum<min, then Vpv_sum=min;

[0056] If Out_Vpv<min, then Out_Vpv=min.

[0057] For the input photovoltaic power loop, the following formula exists:

[0058] Ppv_sum+=Ki_ppv*Ppv_error;

[0059] Out_Ppv=Ppv_sum+Kp_ppv*Ppv_error;

[0060] If Ppv_sum>max, then Ppv_sum=max;

[0061] If Out_Ppv>max, then Out_Ppv=max;

[0062] If Ppv_sum<min, then Ppv_sum=min;

[0063] If Out_Ppv<min, then Out_Ppv=min.

[0064] For the output bus voltage loop, the following equation exists:

[0065] Vbus_sum+=Ki_vbus*Vbus_error;

[0066] Out_Vbus=Vbus_sum+Kp_vbus*Vbus_error;

[0067] If Vbus_sum>max, then Vbus_sum=max;

[0068] If Out_Vbus>max, then Out_Vbus=max;

[0069] If Vbus_sum<min, then Vbus_sum=min;

[0070] If Out_Vbus<min, then Out_Vbus=min.

[0071] Among them, the integral coefficient Ki_vpv and the proportional coefficient Kp_vpv are less than 0, the integral coefficients Ki_ppv and Ki_vbus and the proportional coefficients Kp_ppv and Kp_vbus are greater than 0, max is the above-mentioned preset maximum limit value, and min is the above-mentioned preset minimum limit value.

[0072] After the PV energy storage device begins operation, Vbus < Vbus_ref, Ppv < Ppv_ref, and Vpv > Vpv_ref, resulting in the differences Vbus_error > 0, Ppv_error > 0, and Vpv_error < 0, with the values ​​of Vbus_error and Ppv_error being larger than the absolute value of Vpv_error. Over time, the output of the output bus voltage loop, Out_Vbus, and the output of the input PV power loop, Out_Ppv, will reach their preset maximum limit values ​​before the output of the input PV voltage loop, Out_Vpv. At this point, according to the coupling rules (e.g., the loop corresponding to the minimum output value is the target loop), the three loops competitively couple to determine the input PV voltage loop as the target loop, gaining control of the PV energy storage device. Ipv_ref is controlled by the input PV voltage loop, and Ipv_ref = Out_Vpv.

[0073] When the light intensity increases but the actual power control value does not exceed the target power reference value (other conditions remain unchanged), Vpv increases, Out_Vpv increases, and Vbus rises rapidly to reach Vbus_ref. At this time, Out_Vpv is still less than the preset maximum limit value, but because the working condition is still maintained, Out_Vpv continues to increase, Vbus begins to be greater than Vbus_ref, making Vbus_error < 0, and Out_Vbus begins to decrease from max until Out_Vbus <= Out_Vpv, and Vbus begins to gradually decrease to Vbus_ref.

[0074] Since Vbus starts out greater than Vbus_ref and then drops to Vbus_ref, this process causes the output bus voltage control to overshoot (i.e., overshoot oscillation). Therefore, whether Out_Vbus < Out_Vpv or Vbus > Vbus_ref, directly switching Ipv_ref to the output bus voltage loop control will result in overshoot oscillation. Taking the switching when Out_Vbus < Out_Vpv as an example, when Vbus > Vbus_ref, Ipv_ref will not immediately switch to a decreasing state. Ipv_ref will still remain at Out_Vpv because Out_Vpv is still less than Out_Vbus. Therefore, a certain de-integration time is required, during which the Vbus overshoot will increase until Out_Vbus < Out_Vpv, at which point the output bus voltage loop will control Ipv_ref.

[0075] To solve this problem, the present invention uses PI loop integration to force integral synchronization. When a calculation cycle (i.e., the cycle for calculating the loop output value) ends, the output value, integral value, etc. of the three-loop competitive control have been confirmed, and the integral value of the integrator of the first loop is forced to be equal to the integral value of the integrator of the loop that currently obtains control (i.e., the target loop). For example, while determining that the output after the current three-loop competitive coupling is controlled by the input photovoltaic voltage loop, the forced integral synchronization step is performed, i.e., Ppv_sum=Vpv_sum, Vbus_sum=Vpv_sum. Thus, when Vbus exceeds Vbus_ref in the next control cycle, since Vbus_sum=Vpv_sum, the output bus voltage loop will calculate the corresponding output value based on Vbus_sum, immediately take over the output of the three-loop competition, i.e., control output Ipv_ref. At this time, Out_Vbus is near the previous Ipv_ref, and Vbus will not continue to rise, thereby achieving a relatively smooth loop switching effect.

[0076] It should be noted that the multi-loop control method of the embodiment of the present invention can also be used for but is not limited to devices with DC / AC converters, other devices with DC / DC converters, etc., and the loops that can be set in parallel include but are not limited to current loops, voltage loops, power loops, etc.

[0077] The multi-loop control method of an embodiment of the present invention can synchronize the integrals of all loops and make them equal to the integral value of the target loop each time the control calculation determines the target loop. As a result, when the loop is subsequently switched, the loop that takes over will also be adjusted based on the current working condition, achieving smooth switching, thereby maintaining the stability of control.

[0078] Based on the multi-loop control method of the above embodiment, the present invention proposes a computer-readable storage medium.

[0079] In this embodiment, a computer program is stored on a computer-readable storage medium. When the computer program is executed by a processor, the multi-loop control method of the above embodiment is implemented.

[0080] Figure 4 4 is a structural block diagram of a controller according to an embodiment of the present invention.

[0081] like Figure 4 As shown, controller 500 includes a processor 501 and a memory 503. Processor 501 and memory 503 are connected, for example, via a bus 502. Optionally, controller 500 may further include a transceiver 504. It should be noted that in practical applications, the number of transceivers 504 is not limited to one, and the structure of controller 500 does not constitute a limitation on the embodiments of the present invention.

[0082] The processor 501 may be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It may implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the present disclosure. The processor 501 may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and the like.

[0083] The bus 502 may include a path for transmitting information between the above components. The bus 502 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus. The bus 502 may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 4 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0084] The memory 503 is used to store a computer program corresponding to the multi-loop control method of the above embodiment of the present invention, and the computer program is controlled and executed by the processor 501. The processor 501 is used to execute the computer program stored in the memory 503 to implement the content shown in the above method embodiment.

[0085] Figure 4 The controller 500 shown is merely an example and should not limit the functionality and scope of use of the embodiments of the present invention. It should be noted that the controller 500 is different from the PI controller in the aforementioned loop.

[0086] Figure 5 It is a structural block diagram of a multi-loop control device according to an embodiment of the present invention.

[0087] like Figure 5 As shown, the control device 600 includes: an acquisition module 610 , a determination module 620 and a control module 630 .

[0088] Specifically, the acquisition module 610 is used to obtain the output values ​​of each loop in the current control cycle; the determination module 620 is used to determine the target loop from multiple loops based on the output values; and the control module 630 is used to force the integral value output by the integrator of the first loop to be equal to the integral value output by the integrator of the target loop, so as to be used for calculating the output value of the first loop in the next control cycle, wherein the first loop is a loop among the multiple loops excluding the target loop.

[0089] In some embodiments of the present invention, the acquisition module 610 is specifically used to: for each loop, obtain the target reference value and actual control value of the loop input in the current control cycle, calculate the difference between the target reference value and the actual control value, and obtain the output value of the loop based on the difference.

[0090] In some embodiments of the present invention, the determination module 620 is specifically configured to: use the loop corresponding to the minimum output value as the target loop; or use the loop corresponding to the maximum output value as the target loop.

[0091] In some embodiments of the present invention, before determining the target loop from multiple loops based on the output value, the control module 630 is also used to force the output value to be equal to the preset maximum limit value when the output value is greater than the preset maximum limit value; and / or, when the output value is less than the preset minimum limit value, force the output value to be equal to the preset minimum limit value.

[0092] In some embodiments of the present invention, the control module 630 is further configured to: utilize the output value of the target loop to control the devices applied to the multiple loops in the current control cycle.

[0093] It should be noted that, for other specific implementations of the multi-loop control device according to the embodiment of the present invention, reference may be made to the specific implementations of the multi-loop control method according to the above embodiment of the present invention.

[0094] The multi-loop control device of an embodiment of the present invention can synchronize the integrals of all loops and make them equal to the integral value of the current control loop each time the control calculation determines the switching loop. In this way, the loop that takes over can also be adjusted according to the current working conditions to achieve smooth switching.

[0095] Figure 6 4 is a structural block diagram of a multi-loop control system according to an embodiment of the present invention.

[0096] like Figure 6 As shown, the multi-loop control system 700 includes: a plurality of loops 710, and the multi-loop control device 600 of the above embodiment, or the controller 500 ( Figure 6 (For example, the controller 500 is included).

[0097] The plurality of loops 710 are arranged in parallel, and each loop 710 includes at least an integrator.

[0098] The multi-loop control system of the embodiment of the present invention, through the control device or controller of the above embodiment, can synchronize the integrals of all loops after each control calculation determines the target loop, and make them equal to the integral value of the target loop. Therefore, when the loop is subsequently switched, the loop that takes over will also be adjusted according to the current working condition, thereby achieving smooth switching.

[0099] Figure 7 It is a structural block diagram of a photovoltaic energy storage device according to an embodiment of the present invention.

[0100] like Figure 7 As shown, the photovoltaic energy storage device 800 includes: the multi-loop control system 700 of the above embodiment, wherein the multiple loops in the multi-loop control system 700 include an input photovoltaic voltage loop, an input photovoltaic power loop, and an output bus voltage loop.

[0101] In some embodiments of the present invention, see Figure 2 、 Figure 3 The photovoltaic energy storage device 800 further includes an input photovoltaic current loop, a photovoltaic panel, and a voltage converter (such as a DC / DC converter). The input end of the voltage converter is connected to the photovoltaic panel, and the output end of the voltage converter is used to connect to the load.

[0102] When one of the input photovoltaic voltage loop, the input photovoltaic power loop, and the output bus voltage loop is the target loop, the output value of the target loop is used as the target reference value of the input photovoltaic current loop, so as to perform PWM control on the voltage converter through the input photovoltaic current loop.

[0103] It should be noted that for other specific implementations of the photovoltaic energy storage device 800 according to the embodiment of the present invention, reference may be made to the specific implementations of the multi-loop control method according to the above embodiment.

[0104] The photovoltaic energy storage device of the embodiment of the present invention, through the control system of the above embodiment, can synchronize the integrals of all loops and make them equal to the integral value of the target loop after each control calculation determines the target loop. Therefore, when the loop is subsequently switched, the loop that takes over will also be adjusted based on the current operating condition, achieving smooth switching.

[0105] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device), or in conjunction with such instruction execution system, apparatus, or device. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transmit a program for use by an instruction execution system, apparatus, or device, or in conjunction with such instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection portion having one or more wires (electronic device), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0106] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0107] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0108] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0109] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0110] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0111] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0112] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A multi-loop control method, characterized in that: Multiple loops are arranged in parallel, and each loop includes at least an integrator. The control method includes: Obtaining output values ​​of the multiple loops in the current control cycle; determining a target loop from the plurality of loops according to the output value; The integrated value output by the integrator of the first loop is forced to be equal to the integrated value output by the integrator of the target loop, so as to be used for calculating the output value of the first loop in the next control cycle, wherein the first loop is a loop among the multiple loops excluding the target loop.

2. The multi-loop control method according to claim 1, wherein: The obtaining of the output values ​​of the plurality of loops in the current control period includes: For each of the loops, the target reference value and actual control value of the loop input in the current control cycle are obtained, and the difference between the target reference value and the actual control value is calculated, and the output value of the loop is obtained according to the difference and the integral value output by the integrator of the loop.

3. The multi-loop control method according to claim 1, wherein: Determining a target loop from the multiple loops according to the output value includes: The loop corresponding to the minimum output value is used as the target loop; or The loop corresponding to the maximum output value is used as the target loop.

4. The multi-loop control method according to claim 1, wherein: Before determining the target loop from the multiple loops according to the output value, the control method further includes: If the output value is greater than a preset maximum limit value, forcing the output value to be equal to the preset maximum limit value; and / or If the output value is less than the preset minimum limit value, the output value is forced to be equal to the preset minimum limit value.

5. The multi-loop control method according to claim 1, wherein: The control method is applied to a photovoltaic energy storage device, and the control method further includes: The photovoltaic energy storage device is controlled in the current control cycle using the output value of the target loop.

6. The multi-loop control method according to any one of claims 1 to 5, characterized in that: The loop also includes a proportional and / or a differentiator.

7. A multi-loop control device, characterized in that: A plurality of loops are arranged in parallel, and each of the loops includes at least an integrator, and the control device includes: An acquisition module, used for acquiring the output value of each loop in the current control period; a determination module, configured to determine a target loop from the plurality of loops according to the output value; A control module is configured to force an integral value output by an integrator of a first loop to be equal to an integral value output by an integrator of the target loop, so as to be used for calculating an output value of the first loop in a next control cycle, wherein the first loop is a loop among the multiple loops excluding the target loop.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the multi-loop control method according to any one of claims 1 to 6 is implemented.

9. A controller comprising a memory, a processor, and a computer program stored in the memory, characterized in that: When the computer program is executed by the processor, the multi-loop control method according to any one of claims 1 to 6 is implemented.

10. A multi-loop control system, characterized in that: include: A plurality of loops, wherein the plurality of loops are arranged in parallel, and each of the loops comprises at least an integrator; The multi-loop control device according to claim 8, or the controller according to claim 9.

11. A photovoltaic energy storage device, characterized in that: include: The multi-loop control system according to claim 10, wherein the multiple loops in the multi-loop control system include an input photovoltaic voltage loop, an input photovoltaic power loop, and an output bus voltage loop.

12. The photovoltaic energy storage device according to claim 11, characterized in that: The photovoltaic energy storage device further includes: an input photovoltaic current loop, a photovoltaic panel and a voltage converter, wherein the input end of the voltage converter is connected to the photovoltaic panel, and the output end of the voltage converter is used to connect to a load; When one of the input photovoltaic voltage loop, the input photovoltaic power loop, and the output bus voltage loop is a target loop, the output value of the target loop serves as a target reference value of the input photovoltaic current loop, so as to perform PWM control on the voltage converter through the input photovoltaic current loop.

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