DC bus voltage stabilization control method, device and storage medium for photovoltaic system

Abstract

Embodiments of the present invention disclose a method, device, and storage medium for DC bus voltage stabilization control in a photovoltaic system. Among them, the photovoltaic system includes photovoltaic modules and a Boost boost module, and the photovoltaic modules are connected to the DC bus through the Boost boost module; the method for DC bus voltage stabilization control in the photovoltaic system includes: determining a time-sharing voltage stabilization control loop according to the DC bus operating parameters; determining a time-sharing target voltage error according to the time-sharing voltage stabilization control loop; adjusting the time-sharing target voltage error to determine the adjustment duty ratio of the Boost boost module; adjusting the output voltage of the Boost boost module according to the adjustment duty ratio to maintain the voltage stability of the DC bus. This solution can stabilize the voltage transmitted by the DC bus at the target voltage value and improve the stability of the photovoltaic system.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of power electronics technology, and in particular, to a method and device for controlling the DC bus voltage stabilization of a photovoltaic system and a storage medium. Background Art

[0002] Photovoltaic system power generation is one of the current research hotspots. However, due to the volatility and intermittency of the generated electrical energy, a series of power quality problems will be brought. However, the DC bus voltage of the photovoltaic system is one of the important indicators to measure the safe and stable operation of photovoltaic equipment. Especially in some special working conditions (for example: when the inverter power is suddenly unloaded, the bus voltage will overshoot, and in severe cases, it may even cause the machine to crash), the fluctuation of the DC bus voltage will trigger huge safety accidents or economic losses. Therefore, to ensure the safe and stable operation of photovoltaic equipment, it is urgent to solve the problem of DC bus voltage fluctuation. Summary of the Invention

[0003] The embodiments of the present invention provide a method and device for controlling the DC bus voltage stabilization of a photovoltaic system and a storage medium to improve the stability of the DC bus voltage of the photovoltaic system.

[0004] In a first aspect, the embodiments of the present invention provide a method for controlling the DC bus voltage stabilization of a photovoltaic system. The photovoltaic system includes a photovoltaic module and a Boost boost module, and the photovoltaic module is connected to the DC bus through the Boost boost module;

[0005] The method for controlling the DC bus voltage stabilization of the photovoltaic system includes:

[0006] Determine a time-sharing voltage stabilization control loop according to the DC bus operation parameters;

[0007] Determine a time-sharing target voltage error according to the time-sharing voltage stabilization control loop;

[0008] Adjust the time-sharing target voltage error to determine the adjustment duty ratio of the Boost boost module;

[0009] Adjust the output voltage of the Boost boost module according to the adjustment duty ratio to maintain the voltage of the DC bus stable.

[0010] Optionally, the time-sharing voltage stabilization control loop includes a DC bus control loop and a photovoltaic control loop;

[0011] The step of determining a time-sharing voltage stabilization control loop according to the DC bus operation parameters includes:

[0012] Obtain the DC bus voltage and the DC bus voltage reference value according to the DC bus operation parameters;

[0013] Determine whether the DC bus voltage is greater than the DC bus voltage reference value;

[0014] If so, the time-sharing voltage stabilization control loop is the DC bus control loop;

[0015] If not, the time-sharing voltage stabilization control loop is the photovoltaic control loop.

[0016] Optionally, determining the time-sharing target voltage error according to the time-sharing voltage stabilization control loop includes:

[0017] If the time-sharing voltage stabilization control loop is the DC bus control loop, obtain the DC bus operation parameters and determine the time-sharing target voltage error according to the DC bus operation parameters;

[0018] If the time-sharing voltage stabilization control loop is the photovoltaic control loop, obtain the photovoltaic operation parameters and determine the time-sharing target voltage error according to the photovoltaic operation parameters.

[0019] Optionally, determining the time-sharing target voltage error according to the DC bus operation parameters includes:

[0020] Obtain the DC bus voltage and the DC bus voltage reference value;

[0021] Determine the time-sharing target voltage error according to the DC bus voltage and the DC bus voltage reference value.

[0022] Optionally, determining the time-sharing target voltage error according to the photovoltaic operation parameters includes:

[0023] Obtain the output voltage and output current of the photovoltaic module;

[0024] Determine the reference voltage of the photovoltaic module according to the output voltage and output current of the photovoltaic module;

[0025] Determine the time-sharing target voltage error according to the output voltage of the photovoltaic module and the reference voltage of the photovoltaic module.

[0026] Optionally, adjusting the time-sharing target voltage error to determine the adjustment duty ratio of the Boost boost module includes:

[0027] Perform a first control adjustment on the time-sharing target voltage error to obtain the reference current of the Boost boost module;

[0028] Perform a second control adjustment on the reference current of the Boost boost module and the output current of the photovoltaic module to obtain the adjustment duty ratio.

[0029] Optionally, the first control adjustment includes PI adjustment;

[0030] The reference current I of the Boost boost module pvref is:

[0031]

[0032] where T is the first-order filter time constant, and k p is the proportionality coefficient of the first PI regulation, and k i is the integral coefficient of the first PI regulation, s is a complex variable, and e(s) is the time-sharing target voltage error mentioned above.

[0033] Optionally, the second control adjustment of the reference current of the Boost boost module and the photovoltaic output current to obtain the adjustment duty ratio includes:

[0034] Determine the current error of the Boost boost module according to the reference current of the Boost boost module and the photovoltaic output current;

[0035] Perform a second control adjustment on the current error of the Boost boost module to obtain the adjustment duty ratio.

[0036] In a second aspect, an embodiment of the present invention further provides a photovoltaic system DC bus voltage stabilization control device for the photovoltaic system DC bus voltage stabilization control method provided in any embodiment of the present invention. The photovoltaic system DC bus voltage stabilization control device includes:

[0037] A time-sharing voltage stabilization control loop determination module for determining a time-sharing voltage stabilization control loop according to the DC bus operating parameters;

[0038] A time-sharing target voltage error determination module for determining a time-sharing target voltage error according to the time-sharing voltage stabilization control loop;

[0039] An adjustment duty ratio determination module for adjusting the time-sharing target voltage error to determine the adjustment duty ratio of the Boost boost module;

[0040] An adjustment module for adjusting the output voltage of the Boost boost module according to the adjustment duty ratio to maintain the voltage of the DC bus stable.

[0041] In a third aspect, an embodiment of the present invention further provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, it implements the photovoltaic system DC bus voltage stabilization control method provided in any embodiment of the present invention.

[0042] In the embodiments of the present invention, the time-sharing voltage stabilization control loop that selects a suitable adjustment method is determined according to the DC bus operation parameters to adjust the DC bus voltage, so that the DC bus voltage can be quickly stabilized and responsive. According to the time-sharing voltage stabilization control loop, the time-sharing target voltage error of the suitable adjustment method is determined, so as to subsequently quickly and accurately adjust the DC bus voltage based on the time-sharing target voltage error as the data basis, so that the DC bus voltage is quickly stabilized or continues to be stable. The time-sharing target voltage error is adjusted to determine the adjustment duty ratio of the Boost boost module, and the output voltage of the Boost boost module is adjusted according to the adjustment duty ratio, so that the magnitude of the voltage transmitted by the DC bus is maintained at the target voltage value to maintain the stability of the DC bus voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0044] Figure 1 FIG. 9 is a schematic structural diagram of a photovoltaic system provided by the prior art;

[0045] Figure 2 FIG. 13 is a block diagram of the DC bus voltage stabilization control process of a photovoltaic system provided by the prior art;

[0046] Figure 3 FIG. 17 is a schematic flow chart of a method for controlling the DC bus voltage stabilization of a photovoltaic system provided by the embodiments of the present invention;

[0047] Figure 4 FIG. 21 is a schematic flow chart of the steps for determining the time-sharing voltage stabilization control loop provided by the embodiments of the present invention;

[0048] Figure 5 FIG. 25 is a schematic flow chart of the steps for determining the time-sharing target voltage error according to the DC bus operation parameters provided by the embodiments of the present invention;

[0049] Figure 6 FIG. 29 is a schematic flow chart of the steps for determining the time-sharing target voltage error according to the photovoltaic operation parameters provided by the embodiments of the present invention;

[0050] Figure 7 FIG. 33 is a flow chart of the steps for determining the adjustment duty ratio of the Boost boost module provided by the embodiments of the present invention;

[0051] Figure 8A flowchart of a step of performing a second PI adjustment on the reference current and the photovoltaic output current of the Boost boost module to obtain an adjusted duty cycle provided by an embodiment of the present invention;

[0052] Figure 9 A general block diagram of DC bus voltage stabilization control for a photovoltaic system provided by an embodiment of the present invention;

[0053] Figure 10 A control block diagram of a DC bus control loop provided by an embodiment of the present invention;

[0054] Figure 11 A control block diagram of a photovoltaic control loop provided by an embodiment of the present invention;

[0055] Figure 12 A schematic structural diagram of a DC bus voltage stabilization control device for a photovoltaic system provided by an embodiment of the present invention. Detailed implementation manners

[0056] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0057] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily need to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0058] In order to better explain the solution of the present invention, the structure of the existing photovoltaic system will be briefly described first.

[0059] Figure 1 A schematic structural diagram of a photovoltaic system provided by the prior art, as Figure 1 shown, the photovoltaic system includes a photovoltaic module and a Boost boost module, and the photovoltaic module is connected to the DC bus through the Boost boost module.

[0060] Among them, the photovoltaic module, namely the solar cell module, can convert solar energy into electrical energy. The Boost boost module can convert the low-voltage direct current output by the photovoltaic module into high-voltage direct current and deliver the converted high-voltage direct current to the DC bus.

[0061] Since the electrical energy output by the photovoltaic module is volatile and intermittent, it will cause fluctuations in the DC bus voltage. In response to this, currently, the photovoltaic system uses a photovoltaic-side Boost voltage loop and a DC bus voltage loop to jointly regulate the DC bus. Figure 2 A DC bus voltage stabilization control flow chart provided by the prior art is shown in Figure 2 As shown, the photovoltaic-side Boost voltage U pv and the photovoltaic-side Boost current I pv track the reference voltage U pvref of the photovoltaic module through MPPT, that is, the reference voltage U pvref of the Boost voltage loop; the difference between the photovoltaic-side Boost voltage U pv and the reference voltage U pvref of the Boost voltage loop passes through the first PI regulation to obtain the reference current I pvref of the photovoltaic-side Boost current loop; the difference between the DC bus voltage U bus and the reference voltage U busref of the DC bus voltage loop passes through the second PI regulation to obtain the reference current I limbybus of the DC bus current loop; the reference current I pvref of the photovoltaic-side Boost current loop, the reference current I limbybus of the DC bus current loop, and the photovoltaic-side Boost current I pv pass through the third PI regulation to obtain the duty ratio Duty of the Boost boost circuit, and then control the DC bus voltage.

[0062] In summary, the photovoltaic-side Boost voltage and current loops control the Boost boost circuit, and then control the DC bus voltage. At the same time, the DC bus voltage loop regulates and limits the output of the forward photovoltaic-side Boost voltage loop, so that the photovoltaic-side Boost voltage U pv and the DC bus voltage U bus jointly achieve voltage stabilization. However, the common control structure of the photovoltaic-side Boost voltage loop and the DC bus voltage loop will make it impossible to achieve both the rapidity and stability of the DC bus of the photovoltaic system - that is, if the DC bus voltage response is fast, the voltage oscillation of the DC bus is serious, and if the DC bus voltage is stable, the DC bus voltage response is slow. In particular, when the inverter power on the photovoltaic system is suddenly unloaded, it is difficult for the photovoltaic system to achieve fast and stable control, and finally it will cause the DC bus voltage U bus to overvoltage, and then a downtime phenomenon will occur.

[0063] Figure 3 The figure is a schematic flowchart of a DC bus voltage stabilization control method provided by an embodiment of the present invention. This embodiment is applicable to the voltage control of the DC bus of a photovoltaic system. The DC bus voltage stabilization control method of the photovoltaic system can be executed by a DC bus voltage stabilization control device of the photovoltaic system, and the device can be implemented in a hardware and / or software manner. The DC bus voltage stabilization control method of the photovoltaic system specifically includes the following steps:

[0064] S110. Determine a time-sharing voltage stabilization control loop according to the DC bus operation parameters.

[0065] Among them, the DC bus operation parameters include data such as the DC bus voltage and the DC bus voltage reference value, which can directly reflect the actual operation of the DC bus. The time-sharing voltage stabilization control loop is a loop that adjusts the DC bus voltage in different directions at different times. It includes a DC bus control loop that adjusts the DC bus voltage according to the DC bus operation parameters and a photovoltaic control loop that adjusts the DC bus voltage according to the photovoltaic operation parameters. According to the actual operation of the DC bus, a suitable time-sharing voltage stabilization control loop for adjustment can be selected to adjust the DC bus voltage, so that the DC bus voltage can be quickly stabilized and can quickly respond.

[0066] S120. Determine the time-sharing target voltage error according to the time-sharing voltage stabilization control loop.

[0067] Among them, according to the time-sharing voltage stabilization control loop, the way to adjust the DC bus voltage can be determined. According to the way to adjust the DC bus voltage, the difference between the current voltage and the target voltage of this adjustment path, that is, the time-sharing target voltage error, can be determined, so as to quickly and accurately adjust the DC bus voltage based on the time-sharing target voltage error as the data basis, so that the DC bus voltage can be quickly stabilized or continue to be stable.

[0068] S130. Adjust the time-sharing target voltage error to determine the adjustment duty ratio of the Boost boost module.

[0069] Among them, the Boost boost module includes a DC-DC converter, which can boost the low-voltage DC voltage output by the photovoltaic to a high-voltage DC voltage and deliver the high-voltage DC voltage to the DC bus.

[0070] S140. Adjust the output voltage of the Boost boost module according to the adjustment duty ratio to maintain the voltage of the DC bus stable.

[0071] Among them, the Boost boost module can adjust its own voltage to boost the input photovoltaic voltage to the target voltage value according to the adjustment duty ratio, so that the magnitude of the voltage delivered to the DC bus is maintained at the target voltage value, thereby maintaining the voltage of the DC bus stable.

[0072] In the embodiment of the present invention, according to the DC bus operation parameters, a time-sharing voltage stabilization control loop for selecting a suitable adjustment direction is determined to adjust the DC bus voltage, so that the DC bus voltage can be quickly stabilized and responsive. According to the time-sharing voltage stabilization control loop, a time-sharing target voltage error for a suitable adjustment method is determined, so as to subsequently quickly and accurately adjust the DC bus voltage based on the time-sharing target voltage error as a data basis, so that the DC bus voltage is quickly stabilized or continues to be stabilized. The time-sharing target voltage error is adjusted to determine the adjustment duty ratio of the Boost boost module, and the output voltage of the Boost boost module is adjusted according to the adjustment duty ratio, so that the magnitude of the voltage transmitted by the DC bus is maintained at the target voltage value to maintain the stability of the DC bus voltage.

[0073] It should be noted that: in the case of multiple BOOST boost modules in the photovoltaic system, although the voltages U pv of the Boost boost modules may be different, the DC bus voltage U bus is the same. In this regard, this solution is applicable to the control loop of each BOOST boost module. In addition, since the reference voltage U busref of the DC bus voltage loop and the DC bus voltage U bus of all loops are the same, the control of the DC bus voltage U bus in the control loops of each BOOST boost module can be synchronized to be put into operation and synchronized to exit, thereby achieving the effect of synchronously limiting the outputs of each BOOST boost module.

[0074] Optionally, on the basis of the above embodiment, the time-sharing voltage stabilization control loop includes a DC bus control loop and a photovoltaic control loop.

[0075] Among them, the DC bus control loop is a control loop for adjusting the DC bus voltage according to the DC bus operation parameters; the photovoltaic control loop is a control loop for adjusting the DC bus voltage according to the photovoltaic operation parameters.

[0076] Specifically, Figure 4 is a schematic flow chart of the steps for determining the time-sharing voltage stabilization control loop provided by the embodiment of the present invention. As Figure 4 shown, the steps for determining the time-sharing voltage stabilization control loop according to the DC bus operation parameters are described:

[0077] S210. Obtain the DC bus voltage and the DC bus voltage reference value according to the DC bus operation parameters.

[0078] Among them, the DC bus voltage is the voltage sampling value collected in real time on the DC bus, and the DC bus voltage reference value is the target value of the voltage transmitted on the DC bus.

[0079] S220. Determine whether the DC bus voltage is greater than the DC bus voltage reference value; if so, execute S230; if not, execute S240.

[0080] Among them, when the DC bus voltage is greater than the DC bus voltage reference value, adjusting the DC bus voltage according to the DC bus operating parameters can make the DC bus voltage respond quickly and stably. At this time, the DC bus control loop can be selected to reduce the DC bus voltage and stabilize the voltage value of the DC bus at the DC bus voltage reference value.

[0081] When the DC bus voltage is less than or equal to the DC bus voltage reference value, adjusting the DC bus voltage according to the PV operating parameters can make the DC bus voltage respond quickly and stabilize quickly. At this time, the PV control loop can be selected to reduce the DC bus voltage and stabilize the voltage value of the DC bus at the DC bus voltage reference value.

[0082] S230. The time-sharing voltage stabilization control loop is the DC bus control loop.

[0083] S240. The time-sharing voltage stabilization control loop is the PV control loop.

[0084] Based on the above embodiments, optionally, determining the time-sharing target voltage error according to the time-sharing voltage stabilization control loop includes:

[0085] If the time-sharing voltage stabilization control loop is the DC bus control loop, obtain the DC bus operating parameters and determine the time-sharing target voltage error according to the DC bus operating parameters.

[0086] Specifically, according to the DC bus operating parameters, the DC bus voltage and the DC bus voltage reference value can be obtained. According to the DC bus voltage and the DC bus voltage reference value, the difference between the DC bus voltage and the DC bus voltage reference value, that is, the time-sharing target voltage error, can be known.

[0087] If the time-sharing voltage stabilization control loop is the PV control loop, obtain the PV operating parameters and determine the time-sharing target voltage error according to the PV operating parameters.

[0088] Specifically, the PV operating parameters include the PV module output voltage and the PV module reference voltage, and the time-sharing target voltage error = PV module reference voltage - PV module output voltage.

[0089] Based on the above embodiments, exemplarily, Figure 5 is a schematic flowchart of the steps for determining the time-sharing target voltage error according to the DC bus operating parameters provided by the embodiment of the present invention. As Figure 5 shown, the determination of the time-sharing target voltage error according to the DC bus operating parameters is described:

[0090] S310: Obtain a DC bus voltage and a DC bus voltage reference value.

[0091] S320: Determine a time-sharing target voltage error according to the DC bus voltage and the DC bus voltage reference value.

[0092] Specifically, the time-sharing target voltage error=the DC bus voltage reference−the DC bus voltage.

[0093] Based on the above embodiments, illustratively, Figure 6 A flow chart of a step of determining a time-sharing target voltage error according to photovoltaic operation parameters provided by an embodiment of the present invention is shown in FIG. Figure 6 As shown, the time-sharing target voltage error is determined according to the photovoltaic operation parameters, including:

[0094] S410: Obtain the photovoltaic module output voltage and the photovoltaic module output current.

[0095] S420: Determine a reference voltage of the photovoltaic module according to the output voltage and the output current of the photovoltaic module.

[0096] Among them, inputting the output voltage and output current of the photovoltaic module into the MPPT algorithm can track the maximum power point of the photovoltaic module, thereby determining the reference voltage of the photovoltaic module.

[0097] S430: Determine a time-sharing target voltage error according to the photovoltaic module output voltage and the photovoltaic module reference voltage.

[0098] Wherein, the time-sharing target voltage error = photovoltaic module reference voltage - photovoltaic module output voltage.

[0099] Based on the above embodiment, optionally, Figure 7 A flow chart of the steps for determining the adjustment duty cycle of a Boost module provided by an embodiment of the present invention. Figure 7 As shown, the time-sharing target voltage error is adjusted to determine the adjustment duty cycle of the Boost module, including:

[0100] S510 , performing a first control adjustment on the time-sharing target voltage error to obtain a reference current of the Boost module.

[0101] Specifically, taking PI control regulation as an example, the reference current I of the Boost module is pvref for:

[0102]

[0103] Where T is the first-order filter time constant, k p is the proportional coefficient of the first PI regulation, k iis the integral coefficient of the first PI regulation, s is a complex variable, and e(s) is the time-sharing target voltage error.

[0104] S520: Perform a second control adjustment on the reference current of the Boost boost module and the output current of the photovoltaic module to obtain an adjusted duty cycle.

[0105] Specifically, based on the reference current of the Boost boost module and the photovoltaic output current, the difference between the reference current of the Boost boost module and the photovoltaic output current can be obtained, that is, the current error of the Boost boost module. Perform a second PI regulation on the current error of the Boost boost module to obtain an adjusted duty cycle.

[0106] Based on the above embodiments, optionally, Figure 8 is a flowchart of the steps for performing a second PI regulation on the reference current of the Boost boost module and the photovoltaic output current to obtain an adjusted duty cycle provided by an embodiment of the present invention. As Figure 8 shown, performing a second PI regulation on the reference current of the Boost boost module and the photovoltaic output current to obtain an adjusted duty cycle includes:

[0107] S610: Determine the current error of the Boost boost module according to the reference current of the Boost boost module and the photovoltaic output current.

[0108] Specifically, the current error of the Boost boost module = the reference current of the Boost boost module - the photovoltaic output current.

[0109] S620: Perform a second control adjustment on the current error of the Boost boost module to obtain an adjusted duty cycle.

[0110] Figure 9 is a general block diagram of the DC bus voltage stabilization control of a photovoltaic system provided by an embodiment of the present invention, Figure 10 is a control block diagram of a DC bus control loop provided by an embodiment of the present invention, Figure 11 is a control block diagram of a photovoltaic control loop provided by an embodiment of the present invention.

[0111] Figures 9 - 11 In, U pv is the output voltage of the photovoltaic module, I PV is the output current of the photovoltaic module, U bus is the DC bus voltage, U busref is the DC bus voltage reference value, U pvref is the photovoltaic module reference voltage, I pvref is the reference current of the Boost boost module, Duty is the adjusted duty cycle, and e is the time-sharing target voltage error.

[0112] The expression of the time-sharing target voltage error e is as follows:

[0113]

[0114] When the DC bus voltage U bus > the DC bus voltage reference value U busref (for example, in the case of insufficient photovoltaic power, that is, insufficient power input), as Figure 10 shown, for the error voltage value between the real-time collected DC bus voltage U bus and the DC bus voltage reference value U busref , perform the first control adjustment to obtain the reference current I pvref of the Boost boost module; for the error voltage value between the reference current I pvref of the Boost boost module and the output current I PV of the photovoltaic module, perform the second control adjustment to obtain the adjustment duty cycle Duty of the Boost boost module, so as to adjust the output voltage of the Boost boost module and keep the voltage of the DC bus stable.

[0115] When the DC bus voltage U bus ≤ the DC bus voltage reference value U busref (for example, in the case of over-matched photovoltaic power, that is, excessive power input), as Figure 11 shown, according to the output voltage U pv of the photovoltaic module and the output current I PV of the photovoltaic module, input MPPT to track the reference voltage U pvref of the photovoltaic module, perform the first control adjustment on the error voltage value between the reference voltage U pvref of the photovoltaic module and the output voltage U pv of the photovoltaic module; for the error voltage value between the reference current I pvref of the Boost boost module and the output current I PV of the photovoltaic module, perform the second control adjustment to obtain the adjustment duty cycle Duty of the Boost boost module, so as to adjust the output voltage of the Boost boost module and keep the voltage of the DC bus stable.

[0116] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present method, rather than limiting the protection scope of the present method. For example, the control loop of the loop and the PI adjustment control formula described in the text can be replaced; the time-sharing voltage stabilization control loop and the parameters of the input first control adjustment mentioned can be replaced; the photovoltaic side Boost boost module mentioned can be a single-way Boost boost circuit or a multi-way Boost boost circuit. Although the present method has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present method can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present method.

[0117] Figure 12 FIG. is a schematic structural diagram of a photovoltaic system DC bus voltage stabilization control device provided by an embodiment of the present invention, which is used to execute the photovoltaic system DC bus voltage stabilization control method provided by any embodiment of the present invention.

[0118] As Figure 12 shown, the photovoltaic system DC bus voltage stabilization control device includes:

[0119] A time-sharing voltage stabilization control loop determination module 610, configured to determine a time-sharing voltage stabilization control loop according to the DC bus operation parameters;

[0120] A time-sharing target voltage error determination module 620, configured to determine a time-sharing target voltage error according to the time-sharing voltage stabilization control loop;

[0121] An adjustment duty ratio determination module 630, configured to adjust the time-sharing target voltage error to determine the adjustment duty ratio of the Boost boost module;

[0122] An adjustment module 640, configured to adjust the output voltage of the Boost boost module according to the adjustment duty ratio to maintain the voltage of the DC bus stable.

[0123] In the embodiment of the present invention, the time-sharing voltage stabilization control loop determination module 610 determines a time-sharing voltage stabilization control loop for selecting a schematic adjustment method according to the DC bus operation parameters to adjust the DC bus voltage, so that the DC bus voltage can be quickly stabilized and responsive. The time-sharing target voltage error determination module 620 determines a time-sharing target voltage error suitable for the adjustment method according to the time-sharing voltage stabilization control loop, so as to facilitate subsequent rapid and accurate adjustment of the DC bus voltage based on the time-sharing target voltage error as a data basis, so that the DC bus voltage is quickly stabilized or continues to be stable. The adjustment duty ratio determination module 630 adjusts the time-sharing target voltage error to determine the adjustment duty ratio of the Boost boost module. The adjustment module 640 adjusts the output voltage of the Boost boost module according to the adjustment duty ratio, so that the voltage magnitude transmitted by the DC bus is maintained at the target voltage value to maintain the voltage of the DC bus stable.

[0124] Optionally, the time-sharing voltage stabilization control loop includes a DC bus control loop and a photovoltaic control loop;

[0125] Optionally, the time-sharing voltage stabilization control loop determination module includes:

[0126] An acquisition unit for acquiring the DC bus voltage and the DC bus voltage reference value according to the DC bus operation parameters;

[0127] A judgment unit for judging whether the DC bus voltage is greater than the DC bus voltage reference value;

[0128] If so, the time-sharing voltage stabilization control loop is the DC bus control loop;

[0129] If not, the time-sharing voltage stabilization control loop is the photovoltaic control loop.

[0130] Optionally, the time-sharing target voltage error determination module includes:

[0131] A first determination unit for, if the time-sharing voltage stabilization control loop is the DC bus control loop, acquiring the DC bus operation parameters and determining the time-sharing target voltage error according to the DC bus operation parameters;

[0132] A second determination unit for, if the time-sharing voltage stabilization control loop is the photovoltaic control loop, acquiring the photovoltaic operation parameters and determining the time-sharing target voltage error according to the photovoltaic operation parameters.

[0133] Optionally, the first determination unit is specifically configured to: acquire the DC bus voltage and the DC bus voltage reference value;

[0134] Determine the time-sharing target voltage error according to the DC bus voltage and the DC bus voltage reference value.

[0135] Optionally, the second determination unit is specifically configured to:

[0136] Acquire the output voltage and output current of the photovoltaic module;

[0137] Determine the reference voltage of the photovoltaic module according to the output voltage and output current of the photovoltaic module;

[0138] Determine the time-sharing target voltage error according to the output voltage of the photovoltaic module and the reference voltage of the photovoltaic module.

[0139] Optionally, the duty ratio adjustment determination module includes:

[0140] A reference current acquisition unit for performing a first control adjustment on the time-sharing target voltage error to obtain the reference current of the Boost boost module;

[0141] The duty ratio adjustment acquisition unit is used to perform a second control adjustment on the reference current of the Boost boost module and the output current of the photovoltaic module to obtain an adjusted duty ratio.

[0142] Optionally, the duty ratio adjustment acquisition unit is specifically used for:

[0143] Determine the current error of the Boost boost module according to the reference current of the Boost boost module and the photovoltaic output current;

[0144] Perform a second control adjustment on the current error of the Boost boost module to obtain an adjusted duty ratio.

[0145] An embodiment of the present invention also provides a computer-readable storage medium. A computer program is stored on the computer-readable storage medium. When the computer program is executed by a processor, it implements the DC bus voltage stabilization control method of the photovoltaic system provided in any embodiment of the present invention.

[0146] The computer storage medium of the embodiment of the present invention can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to: an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. The computer-readable storage medium includes (a non-exhaustive list): an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (Random Access Memory, RAM), a read-only memory (Read-Only Memory, ROM), an electrically erasable, programmable read-only memory (electrically erasable, programmable Read-Only Memory, EPROM), a flash memory, an optical fiber, a portable compact disc read-only memory (Compact Disc Read-Only Memory, CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present invention, the computer-readable storage medium can be any tangible medium that contains or stores a program, and the program can be used by or in combination with an instruction execution system, apparatus, or device.

[0147] A computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the foregoing. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device.

[0148] The program code contained on a computer-readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, Radio Frequency (RF), etc., or any suitable combination of the foregoing.

[0149] The computer program code for performing the operations of the present disclosure may be written in one or more programming languages or combinations of programming languages. The programming languages include object-oriented programming languages such as Java, Smalltalk, C++, Ruby, Go, and also include conventional procedural programming languages such as the "C" language or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, executed as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0150] Those skilled in the art should understand that the term user terminal encompasses any suitable type of wireless user equipment, such as a mobile phone, a portable data processing device, a portable web browser, or a vehicle-mounted mobile station.

[0151] In general, various embodiments of the present invention may be implemented in hardware or a dedicated circuit, software, logic, or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that can be executed by a controller, a microprocessor, or other computing devices, although the present invention is not limited thereto.

[0152] Embodiments of the present invention can be implemented by a data processor of a mobile device executing computer program instructions, for example, in a processor entity, or by hardware, or by a combination of software and hardware. The computer program instructions may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-related instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages.

[0153] Any block diagram of a logical process in the drawings of the present invention may represent program steps, or may represent interconnected logical circuits, modules, and functions, or may represent a combination of program steps and logical circuits, modules, and functions. The computer program may be stored in a memory. The memory may be of any type suitable for the local technical environment and may be implemented using any suitable data storage technology, such as, but not limited to, read-only memory (ROM), random access memory (RAM), optical memory devices and systems (Digital Versatile Disc (DVD) or Compact Disc (CD)), etc. The computer-readable medium may include non-transitory storage media. The data processor may be of any type suitable for the local technical environment, such as, but not limited to, a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA), and a processor based on a multi-core processor architecture.

[0154] It should be understood that the various forms of the processes shown above may be used, steps may be reordered, added, or deleted. For example, the steps recited in the present invention may be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved, and no limitation is made herein.

[0155] The above specific embodiments do not constitute a limitation on the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A photovoltaic system DC bus voltage stabilization control method, characterized in that: The photovoltaic system comprises a photovoltaic module and a Boost module, and the photovoltaic module is connected to a DC bus through the Boost module; The photovoltaic system DC bus voltage stabilization control method comprises: Determine a time-sharing voltage stabilization control loop according to the DC bus operating parameters; the time-sharing voltage stabilization control loop includes a DC bus control loop and a photovoltaic control loop; Determining a time-sharing target voltage error according to the time-sharing voltage stabilization control loop; Determining the time-sharing target voltage error according to the time-sharing voltage stabilization control loop includes: If the time-sharing voltage stabilization control loop is a DC bus control loop, then obtaining a DC bus operating parameter, and determining the time-sharing target voltage error according to the DC bus operating parameter; If the time-sharing voltage stabilization control loop is a photovoltaic control loop, photovoltaic operation parameters are obtained, and the time-sharing target voltage error is determined according to the photovoltaic operation parameters; the photovoltaic operation parameters include the photovoltaic module output voltage and the photovoltaic module reference voltage; The time-sharing target voltage error is adjusted to determine the adjustment duty cycle of the Boost module; Adjusting the output voltage of the Boost module according to the adjusted duty cycle to maintain the voltage of the DC bus stable; The step of adjusting the time-sharing target voltage error to determine the adjustment duty cycle of the Boost module includes: Performing a first control adjustment on the time-sharing target voltage error to obtain a reference current of the Boost module; Performing a second control adjustment on the reference current of the Boost module and the output current of the photovoltaic module to obtain the adjustment duty cycle; The first control regulation includes PI regulation; The reference current I of the Boost module pvref for: ， Where T is the first-order filter time constant, k p is the proportional coefficient of the first PI regulation, k i is the integral coefficient of the first PI regulation, s is a complex variable, and e(s) is the time-sharing target voltage error.

2. The photovoltaic system DC bus voltage stabilization control method according to claim 1, characterized in that: The step of determining the time-sharing voltage stabilization control loop according to the DC bus operating parameters includes: According to the DC bus operating parameters, the DC bus voltage and the DC bus voltage reference value are obtained; Determine whether the DC bus voltage is greater than the DC bus voltage reference value; If yes, then the time-sharing voltage stabilization control loop is the DC bus control loop; If not, the time-sharing voltage stabilization control loop is the photovoltaic control loop.

3. The photovoltaic system DC bus voltage stabilization control method according to claim 1, characterized in that: The step of determining the time-sharing target voltage error according to the DC bus operation parameter includes: Obtain the DC bus voltage and the DC bus voltage reference value; A time-sharing target voltage error is determined according to the DC bus voltage and the DC bus voltage reference value.

4. The photovoltaic system DC bus voltage stabilization control method according to claim 1, characterized in that: The step of determining the time-sharing target voltage error according to the photovoltaic operation parameter includes: Obtain the output voltage and current of the photovoltaic module; Determining a photovoltaic assembly reference voltage according to the photovoltaic assembly output voltage and the photovoltaic assembly output current; A time-sharing target voltage error is determined according to the photovoltaic assembly output voltage and the photovoltaic assembly reference voltage.

5. The photovoltaic system DC bus voltage stabilization control method according to claim 1, characterized in that: The second control adjustment of the reference current and the photovoltaic output current of the Boost module to obtain the adjustment duty cycle includes: Determining a current error of the Boost module according to a reference current of the Boost module and the photovoltaic output current; A second control adjustment is performed on the current error of the Boost module to obtain the adjustment duty cycle.

6. A photovoltaic system DC bus voltage stabilization control device, used to execute the photovoltaic system DC bus voltage stabilization control method according to any one of claims 1 to 5, characterized in that: include: A time-sharing voltage stabilization control loop determination module, used to determine the time-sharing voltage stabilization control loop according to the DC bus operating parameters; the time-sharing voltage stabilization control loop includes a DC bus control loop and a photovoltaic control loop; A time-sharing target voltage error determination module, used to determine the time-sharing target voltage error according to the time-sharing voltage stabilization control loop; The time-sharing target voltage error determination module includes: A first determining unit, configured to obtain a DC bus operating parameter if the time-sharing voltage stabilization control loop is a DC bus control loop, and determine the time-sharing target voltage error according to the DC bus operating parameter; A second determination unit is used to obtain photovoltaic operation parameters if the time-sharing voltage stabilization control loop is a photovoltaic control loop, and determine the time-sharing target voltage error according to the photovoltaic operation parameters; the photovoltaic operation parameters include a photovoltaic module output voltage and a photovoltaic module reference voltage; A duty cycle adjustment determination module is used to adjust the time-sharing target voltage error and determine the adjustment duty cycle of the Boost module; The regulating module is used to regulate the output voltage of the Boost module according to the regulating duty cycle to maintain the voltage of the DC bus stable.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the photovoltaic system DC bus voltage stabilization control method as described in any one of claims 1 to 5 is implemented.

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