A power distribution method and device for a light storage power station

Abstract

This application discloses a power allocation method and apparatus for a photovoltaic-storage power station. The method obtains the apparent power of the photovoltaic-storage power station. If the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, the power demand of the photovoltaic-storage power station is determined according to the operating mode of the photovoltaic-storage power station. Based on the power demand, the first power of the adjustable power unit in the photovoltaic-storage power station is preferentially adjusted until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer. This achieves a redistribution of active and reactive power between the photovoltaic-storage power station, which can ensure the power demand of the photovoltaic-storage power station while protecting the transformer from overload.

Description

Technical Field

[0001] This application relates to the field of photovoltaic power generation technology, and more specifically, to a power distribution method and apparatus for a photovoltaic power storage station. Background Technology

[0002] Currently, when the total capacity of power units such as photovoltaic generators and energy storage systems in a photovoltaic power station exceeds the overload protection capacity threshold of the transformer, it is necessary to redistribute the power of the power units to prevent damage to the transformer due to overload conditions.

[0003] However, the question arises as to how to redistribute the power of the power units. Summary of the Invention

[0004] This application provides the following technical solution:

[0005] This application provides a power allocation method for a photovoltaic-storage power station, characterized by comprising:

[0006] Obtain the apparent power of the photovoltaic and energy storage power station;

[0007] If the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, the power demand of the photovoltaic-storage power station shall be determined according to the operating mode of the photovoltaic-storage power station.

[0008] Based on the power demand, the first power of the adjustable power unit in the photovoltaic-storage power station is adjusted first until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer. Wherein, if the power demand is an active power demand, the first power is reactive power; if the power demand is a reactive power demand, the first power is active power.

[0009] Optionally, if the photovoltaic-storage power station has multiple operating modes, determining the power requirement of the photovoltaic-storage power station based on its operating mode includes:

[0010] The operating modes are sorted in descending order of priority.

[0011] Select the operating mode that ranks highest among the various operating modes and has not participated in determining the power demand, and determine the power demand of the photovoltaic-storage power station based on the selected operating mode.

[0012] Optionally, the step of preferentially adjusting the first power of the adjustable power unit in the photovoltaic-storage power station based on the power demand until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer includes:

[0013] Based on the power requirement, the first power of the adjustable power unit in the photovoltaic-storage power station is adjusted first.

[0014] If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power, the adjustment ends.

[0015] If the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer after adjusting the first power, return to the step of selecting the operating mode that is ranked first among the various operating modes and has not participated in determining the power demand.

[0016] Optionally, based on the power demand, the first power of the adjustable power unit in the photovoltaic-storage power station is preferentially adjusted until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer, including:

[0017] Based on the transformer overload protection capacity threshold, the transformer real-time second power corresponding to the power demand, and the first power of the non-adjustable power unit, the first remaining available power boundary range is determined.

[0018] Based on the operating mode, a first initial target value for the first power of the adjustable power unit is determined;

[0019] If the first initial target value is within the first remaining available boundary range, determine whether the first initial target value is within the chargeable / dischargeable first power boundary range;

[0020] If so, the value of the first power of the adjustable power unit shall be adjusted to the first initial target value first.

[0021] If not, select the first intermediate target value that is closest to the first initial target value from the range of the first rechargeable and dischargeable power boundary, and preferentially adjust the value of the first power of the adjustable power unit to the first intermediate target value;

[0022] If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power, the adjustment ends.

[0023] Optionally, the method further includes:

[0024] If the first initial target value is not within the first remaining available boundary range, select the second intermediate target value that is closest to the first initial target value from within the first remaining available boundary range;

[0025] Determine whether the second intermediate target value is within the range of the first chargeable / dischargeable power boundary;

[0026] If so, the value of the first power of the adjustable power unit shall be adjusted to the second intermediate target value first;

[0027] If not, select the third intermediate target value that is closest to the second intermediate target value from the range of the first power boundary of the rechargeable and dischargeable power, and preferentially adjust the value of the first power of the adjustable power unit to the third intermediate target value;

[0028] If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power, the adjustment ends.

[0029] Optionally, based on the transformer overload protection capacity threshold, the real-time power of the transformer corresponding to the power demand, and the first power of the non-adjustable power unit, a first remaining available power boundary range is determined, including:

[0030] Determine the square root of the difference between the square of the overload protection capacity threshold of the transformer and the square of the real-time second power of the transformer;

[0031] The difference between the negative square root value and the value of the first power of the non-adjustable power unit is used as the first boundary lower limit value, and the difference between the square root value and the value of the first power of the non-adjustable power unit is used as the first boundary upper limit value. The range between the first boundary lower limit value and the first boundary upper limit value is determined as the first remaining available power boundary range.

[0032] Optionally, the method further includes:

[0033] If the apparent power of the photovoltaic-storage power station still exceeds the overload protection capacity threshold of the transformer after adjusting the first power, the real-time first power of the transformer is determined based on the value of the first power after adjustment of the adjustable power unit and the value of the first power of the non-adjustable power unit.

[0034] Based on the transformer overload protection capacity threshold, the transformer real-time first power, and the second power of the non-adjustable power unit, a second remaining available power boundary range is determined, wherein the type of the second power of the non-adjustable power unit is different from the type of its first power;

[0035] Based on the operating mode, a second initial target value for the second power of the adjustable power unit is determined;

[0036] If the second initial target value is within the range of the second remaining available boundary, determine whether the second initial target value is within the range of the second chargeable / dischargeable power boundary;

[0037] If so, the value of the second power of the adjustable power unit shall be adjusted to the second initial target value first;

[0038] If not, select the fourth intermediate target value that is closest to the second initial target value from the range of the second rechargeable power boundary, and preferentially adjust the value of the second power of the adjustable power unit to the fourth intermediate target value.

[0039] Preferably, the method further includes:

[0040] If the second initial target value is not within the second remaining available boundary range, select the fifth intermediate target value that is closest to the second initial target value from within the second remaining available boundary range;

[0041] Determine whether the fifth intermediate target value is within the range of the chargeable / dischargeable second power boundary;

[0042] If so, the value of the second power of the adjustable power unit shall be adjusted to the fifth intermediate target value first;

[0043] If not, select the sixth intermediate target value that is closest to the fifth intermediate target value from the range of the second rechargeable power boundary, and preferentially adjust the value of the second power of the adjustable power unit to the sixth intermediate target value.

[0044] Optionally, based on the transformer overload protection capacity threshold, the transformer's real-time first power, and the second power of the non-adjustable power unit, a second remaining available power boundary range is determined, including:

[0045] Determine the square root of the difference between the square of the transformer overload protection capacity threshold and the square of the transformer's real-time first power.

[0046] The difference between the negative square root value and the value of the second power of the non-adjustable power unit is taken as the second boundary lower limit value, and the difference between the square root value and the value of the second power of the non-adjustable power unit is taken as the second boundary upper limit value. The range between the second boundary lower limit value and the second boundary upper limit value is determined as the second remaining available power boundary range.

[0047] Optionally, if there are multiple adjustable power units, based on the power requirement, the first power of the adjustable power unit in the photovoltaic-storage power station is adjusted first until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer, including:

[0048] The adjustable power units are sorted in descending order of priority.

[0049] Select the adjustable power unit that is ranked first and has not been adjusted from among the adjustable power units, and preferentially adjust the first power of the adjustable power unit that is ranked first and has not been adjusted.

[0050] If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power of the first adjustable power unit that is ranked first and has not been adjusted, the adjustment ends.

[0051] Optionally, the method further includes:

[0052] If the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer after adjusting the first power of the first adjustable power unit that has not been adjusted, the second power of the first adjustable power unit that has not been adjusted is adjusted, and the second power is of a different type than the first power.

[0053] If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the second power of the first adjustable power unit that has not been adjusted before, the adjustment ends.

[0054] If the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer after adjusting the second power of the adjustable power unit that is ranked first and has not been adjusted, the process returns to the step of selecting the adjustable power unit that is ranked first and has not been adjusted from among the adjustable power units.

[0055] Optionally, if there are multiple adjustable power units, based on the power requirement, the first power of the adjustable power unit in the photovoltaic-storage power station is adjusted first until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer, including:

[0056] The adjustable power units are sorted in descending order of priority.

[0057] Select the adjustable power unit that is ranked first and has not participated in the first power adjustment from among the adjustable power units, and preferentially adjust the first power of the adjustable power unit that is ranked first and has not participated in the first power adjustment.

[0058] If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power of the adjustable power unit that is ranked first and has not participated in the first power adjustment, the adjustment ends.

[0059] If, after adjusting the first power of the adjustable power unit that ranks first and has not participated in the first power adjustment, the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, and there are still adjustable power units that have not participated in the first power adjustment, then the step of selecting the adjustable power unit that ranks first and has not participated in the first power adjustment from among the adjustable power units is returned to be executed.

[0060] Optionally, the method further includes:

[0061] If the apparent power of the photovoltaic-storage power station exceeds the transformer overload protection capacity threshold after adjusting the first power of the adjustable power unit that is ranked first and has not participated in the first power adjustment, and there is no adjustable power unit that has not participated in the first power adjustment, then select the adjustable power unit that is ranked first and has not participated in the second power adjustment from among the adjustable power units, and prioritize adjusting the second power of the adjustable power unit that is ranked first and has not participated in the second power adjustment.

[0062] If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the second power of the adjustable power unit that is ranked first and has not participated in the second power adjustment, the adjustment ends.

[0063] If, after adjusting the second power of the adjustable power unit that ranks first and has not participated in the second power adjustment, the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, and there are still adjustable power units that have not participated in the second power adjustment, then the step of selecting the adjustable power unit that ranks first and has not participated in the second power adjustment from among the adjustable power units is returned to be executed.

[0064] Another aspect of this application provides a power distribution device for a photovoltaic-storage power station, comprising:

[0065] The acquisition module is used to obtain the apparent power of the photovoltaic-storage power station;

[0066] The determination module is used to determine the power demand of the photovoltaic-storage power station based on the operating mode of the photovoltaic-storage power station if the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer.

[0067] The adjustment module is used to adjust the first power of the adjustable power unit in the photovoltaic-storage power station based on the power demand, until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer. If the power demand is an active power demand, the first power is reactive power; if the power demand is a reactive power demand, the first power is active power.

[0068] In this application, by obtaining the apparent power of the photovoltaic-storage power station, if the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, the power demand of the photovoltaic-storage power station is determined according to the operating mode of the photovoltaic-storage power station; based on the power demand, the first power of the adjustable power unit in the photovoltaic-storage power station is preferentially adjusted until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer, thereby realizing the redistribution between the active power and reactive power of the photovoltaic-storage power station, which can ensure the power demand of the photovoltaic-storage power station while protecting the transformer from overload. Attached Figure Description

[0069] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0070] Figure 1 A schematic flowchart illustrating a power allocation method for a photovoltaic-storage power station provided in Embodiment 1 of this application;

[0071] Figure 2 A schematic diagram of one type of electrical wiring for a photovoltaic-storage power station provided in this application;

[0072] Figure 3 A schematic flowchart illustrating a power allocation method for a photovoltaic-storage power station provided in Embodiment 8 of this application;

[0073] Figure 4 A schematic flowchart illustrating a power allocation method for a photovoltaic-storage power station provided in Embodiment 9 of this application;

[0074] Figure 5 A schematic flowchart illustrating a power allocation method for a photovoltaic-storage power station provided in Embodiment 10 of this application;

[0075] Figure 6 A schematic flowchart illustrating a power allocation method for a photovoltaic-storage power station provided in Embodiment 11 of this application;

[0076] Figure 7 A schematic flowchart illustrating a power allocation method for a photovoltaic-storage power station provided in Embodiment 12 of this application;

[0077] Figure 8 This is a schematic diagram of the structure of a power distribution device for a photovoltaic-storage power station provided in this application. Detailed Implementation

[0078] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0079] To address the aforementioned issues, this application provides a power allocation method for photovoltaic-storage power stations, which will be described below.

[0080] Reference Figure 1 This is a flowchart illustrating a power allocation method for a photovoltaic-storage power station provided in Embodiment 1 of this application. Figure 1 As shown, the method may include, but is not limited to, the following steps:

[0081] Step S11: Obtain the apparent power of the photovoltaic-storage power station.

[0082] In this embodiment, the power units of the photovoltaic energy storage power station (e.g., Figure 2 The apparent power of a photovoltaic-storage power station is determined based on the real-time active and reactive power of photovoltaic systems and energy storage systems (such as solar photovoltaic systems and energy storage systems). Apparent power can represent the capacity of a photovoltaic-storage power station.

[0083] Of course, the apparent power of the photovoltaic-storage power station can also be directly collected.

[0084] The power units of a photovoltaic-storage power station may include, but are not limited to, adjustable power units and non-adjustable power units. The power of adjustable power units is adjustable, while the power of non-adjustable power units is not adjustable.

[0085] Step S12: If the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, determine the power demand of the photovoltaic-storage power station according to the operating mode of the photovoltaic-storage power station.

[0086] In this embodiment, the transformer overload protection capacity threshold can be understood as: the main transformer in the photovoltaic-storage power station (e.g., such as...) Figure 2 The overload protection capacity threshold of the main transformer shown in the figure.

[0087] The operating modes of the photovoltaic-storage power station may include: stability control mode, primary frequency regulation mode, rotational inertia mode, AVC mode, etc. At least one or more of the following grid safety modes are allowed: stability control mode, primary frequency regulation mode, and rotational inertia mode; or, power generation curve smoothing, peak shifting, peak-valley arbitrage, power factor control, etc. At least one or more of the following user-defined modes are allowed: power generation curve smoothing, peak shifting, and peak-valley arbitrage.

[0088] Specifically, the power demand corresponding to the operating mode of the photovoltaic-storage power station can be determined from the pre-established correspondence between multiple operating modes and power demands. For example, in the AVC mode, the photovoltaic-storage power station mainly needs to provide reactive power support; therefore, according to the AVC mode, the power demand of the photovoltaic-storage power station can be determined as reactive power demand. Similarly, in the power factor control mode, the photovoltaic-storage power station mainly needs to provide reactive power support; therefore, according to the power factor control mode, the power demand of the photovoltaic-storage power station can be determined as reactive power demand.

[0089] It should be noted that, Figure 2This is merely one possible electrical wiring diagram for a photovoltaic-storage power station and is not intended to limit the scope of such stations.

[0090] Step S13: Based on the power demand, prioritize adjusting the first power of the adjustable power unit in the photovoltaic-storage power station until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer. Wherein, if the power demand is an active power demand, the first power is reactive power; if the power demand is a reactive power demand, the first power is active power.

[0091] This step may include, but is not limited to:

[0092] S131. Based on the transformer overload protection capacity threshold, the transformer real-time second power corresponding to the power demand, and the first power of the non-adjustable power unit, determine the first remaining available power boundary range.

[0093] S132. Based on the operating mode, determine the first initial target value of the first power of the adjustable power unit.

[0094] The initial target value can meet the power requirements of the photovoltaic-storage power station in the stated operating mode.

[0095] S133. Determine whether the first initial target value is within the range of the first remaining available boundary.

[0096] If yes, proceed to step S134; otherwise, proceed to step S137.

[0097] S134. Determine whether the first initial target value is within the range of the first chargeable / dischargeable power boundary.

[0098] The first power boundary range that can be charged and discharged may include, but is not limited to, [-maximum chargeable first power, maximum dischargeable first power]. If the first power is reactive power, the first power boundary range that can be charged and discharged may include, but is not limited to, [-maximum chargeable reactive power, maximum dischargeable reactive power].

[0099] If yes, proceed to step S135; otherwise, proceed to step S136.

[0100] S135. The value of the first power of the adjustable power unit is preferentially adjusted to the first initial target value.

[0101] S136. Select the first intermediate target value that is closest to the first initial target value from the range of the first rechargeable and dischargeable power boundary, and preferentially adjust the value of the first power of the adjustable power unit to the first intermediate target value.

[0102] Selecting a first intermediate target value that is closest to the first initial target value from the range of the first rechargeable and dischargeable power boundary may include, but is not limited to:

[0103] S1361. Calculate the absolute values ​​of the differences between the two boundary values ​​of the first power boundary range of the rechargeable and dischargeable power and the first initial target value, and take the boundary value corresponding to the smaller absolute value as the first intermediate target value that is closest to the first initial target value.

[0104] S137. Select the second intermediate target value that is closest to the first initial target value from the first remaining available boundary range.

[0105] The method for selecting the second intermediate target value can be found in the relevant description of step S1361, and will not be repeated here.

[0106] S138. Determine whether the second intermediate target value is within the range of the first rechargeable / dischargeable power boundary.

[0107] If yes, proceed to step S139; otherwise, proceed to step S1310.

[0108] S139. The value of the first power of the adjustable power unit is preferentially adjusted to the second intermediate target value.

[0109] S1310. Select the third intermediate target value that is closest to the second intermediate target value from the range of the first power boundary of the rechargeable and dischargeable power, and preferentially adjust the value of the first power of the adjustable power unit to the third intermediate target value.

[0110] The method for selecting the third intermediate target value can be found in the relevant description of step S1361, and will not be repeated here.

[0111] S1311. If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power, the adjustment ends.

[0112] After adjusting the first power, the apparent power of the photovoltaic-storage power station needs to be re-determined. If the re-determined apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer, the adjustment ends.

[0113] Of course, if the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer after adjusting the first power, the following steps can also be performed:

[0114] S1312. Based on the value of the first power after adjustment of the adjustable power unit and the value of the first power of the non-adjustable power unit, determine the real-time first power of the transformer.

[0115] Step S1312 may include, but is not limited to, taking the sum of the adjusted first power value of the adjustable power unit and the first power value of the non-adjustable power unit as the value of the real-time first power of the transformer.

[0116] If the power demand is active power demand, then the first power is reactive power. Specifically, the sum of the adjusted reactive power value of the adjustable power unit and the reactive power value of the non-adjustable power unit is taken as the real-time reactive power value of the transformer.

[0117] If the power demand is reactive power demand, then the first power is active power. Specifically, the sum of the adjusted active power value of the adjustable power unit and the active power value of the non-adjustable power unit is taken as the real-time active power value of the transformer.

[0118] S1313. Based on the transformer overload protection capacity threshold, the transformer real-time first power, and the second power of the non-adjustable power unit, determine the second remaining available power boundary range, wherein the type of the second power of the non-adjustable power unit is different from the type of its first power.

[0119] If the power demand is an active power demand, then the first power is reactive power and the second power is active power; if the power demand is a reactive power demand, then the first power is active power and the second power is reactive power.

[0120] S1314. Based on the operating mode, determine the second initial target value of the second power of the adjustable power unit.

[0121] S1315. Determine whether the second initial target value is within the range of the second remaining available boundary.

[0122] If yes, proceed to step S1316; otherwise, proceed to step S1319.

[0123] S1316. Determine whether the second initial target value is within the range of the second chargeable / dischargeable power boundary.

[0124] The chargeable and dischargeable second power boundary range may include, but is not limited to: [-maximum chargeable second power, maximum dischargeable second power]. If the first power is reactive power, the second power is active power, and the chargeable and dischargeable second power boundary range may include, but is not limited to: [-maximum chargeable active power, maximum dischargeable active power].

[0125] If yes, proceed to step S1317; otherwise, proceed to step S1318.

[0126] S1317. The value of the second power of the adjustable power unit is preferentially adjusted to the second initial target value.

[0127] S1318. Select the fourth intermediate target value that is closest to the second initial target value from the range of the second rechargeable power boundary, and preferentially adjust the value of the second power of the adjustable power unit to the fourth intermediate target value.

[0128] The method for selecting the fourth intermediate target value can be found in the relevant description of step S1361, and will not be repeated here.

[0129] S1319. Select the fifth intermediate target value that is closest to the second initial target value from the range of the second remaining available boundary.

[0130] The method for selecting the fifth intermediate target value can be found in the relevant description of step S1361, and will not be repeated here.

[0131] S1320. Determine whether the fifth intermediate target value is within the range of the chargeable / dischargeable second power boundary;

[0132] If yes, proceed to step S1321; otherwise, proceed to step S1322.

[0133] S1321. The value of the second power of the adjustable power unit is preferentially adjusted to the fifth intermediate target value.

[0134] S1322. Select the sixth intermediate target value that is closest to the fifth intermediate target value from the range of the second power boundary of the rechargeable and dischargeable power, and preferentially adjust the value of the second power of the adjustable power unit to the sixth intermediate target value.

[0135] The method for selecting the sixth intermediate target value can be found in the relevant description of step S1361, and will not be repeated here.

[0136] In this embodiment, prioritizing the adjustment of the first power of the adjustable power unit in the photovoltaic-storage power station based on the power demand may include: prioritizing the reduction of the first power of the adjustable power unit in the photovoltaic-storage power station based on the power demand. For example, based on the active power demand, prioritizing the reduction of the reactive power of the adjustable power unit in the photovoltaic-storage power station to ensure that the active power demand of the photovoltaic-storage power station is met while protecting the main transformer from overload; or, based on the reactive power demand, prioritizing the reduction of the active power of the adjustable power unit in the photovoltaic-storage power station to ensure that the reactive power demand of the photovoltaic-storage power station is met while protecting the main transformer from overload.

[0137] In this embodiment, by obtaining the apparent power of the photovoltaic-storage power station, if the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, the power demand of the photovoltaic-storage power station is determined according to the operating mode of the photovoltaic-storage power station. Based on the power demand, the first power of the adjustable power unit in the photovoltaic-storage power station is adjusted first until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer, thereby realizing the redistribution between the active power and reactive power of the photovoltaic-storage power station. This can ensure the power demand of the photovoltaic-storage power station while protecting the transformer from overload.

[0138] As another optional embodiment of this application, this embodiment 2 is mainly a refinement of step S13 in embodiment 1 above. Step S13 may include, but is not limited to, the following steps:

[0139] S131. Based on the transformer overload protection capacity threshold, the transformer real-time second power corresponding to the power demand, and the first power of the non-adjustable power unit, determine the first remaining available power boundary range.

[0140] S132. Based on the operating mode, determine the first initial target value of the first power of the adjustable power unit.

[0141] The initial target value can meet the power requirements of the photovoltaic-storage power station in the stated operating mode.

[0142] S133. Determine whether the first initial target value is within the range of the first remaining available boundary.

[0143] If so, proceed to step S134.

[0144] S134. Determine whether the first initial target value is within the range of the first chargeable / dischargeable power boundary.

[0145] The first power boundary range that can be charged and discharged may include, but is not limited to, [-maximum chargeable first power, maximum dischargeable first power]. If the first power is reactive power, the first power boundary range that can be charged and discharged may include, but is not limited to, [-maximum chargeable reactive power, maximum dischargeable reactive power].

[0146] If yes, proceed to step S135; otherwise, proceed to step S136.

[0147] S135. The value of the first power of the adjustable power unit is preferentially adjusted to the first initial target value.

[0148] S136. Select the first intermediate target value that is closest to the first initial target value from the range of the first rechargeable and dischargeable power boundary, and preferentially adjust the value of the first power of the adjustable power unit to the first intermediate target value.

[0149] Selecting a first intermediate target value that is closest to the first initial target value from the range of the first rechargeable and dischargeable power boundary may include, but is not limited to:

[0150] S1361. Calculate the absolute values ​​of the differences between the two boundary values ​​of the first power boundary range of the rechargeable and dischargeable power and the first initial target value, and take the boundary value corresponding to the smaller absolute value as the first intermediate target value that is closest to the first initial target value.

[0151] After steps S131-S136, if the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power, the adjustment ends.

[0152] As another optional embodiment of this application, this embodiment 3 is mainly a refinement of step S131 in embodiment 1 above. Step S131 may include, but is not limited to, the following steps:

[0153] S13110. Determine the square root of the difference between the square of the overload protection capacity threshold of the transformer and the square of the real-time second power of the transformer.

[0154] S13111. The difference between the negative square root value and the value of the first power of the non-adjustable power unit is taken as the first boundary lower limit value, and the difference between the square root value and the value of the first power of the non-adjustable power unit is taken as the first boundary upper limit value. The range between the first boundary lower limit value and the first boundary upper limit value is determined as the first remaining available power boundary range.

[0155] Wherein, if the power demand is active power demand, the real-time second power of the transformer corresponds to the real-time active power of the transformer, and the first power of the non-adjustable power unit is reactive power. Specifically, the first remaining available power boundary range can be determined according to the following formula:

[0156]

[0157] Wherein, if the power demand is reactive power demand, the real-time second power of the transformer corresponds to the real-time reactive power of the transformer, and the first power of the non-adjustable power unit is active power. Specifically, the first remaining available power boundary range can be determined according to the following formula:

[0158]

[0159] As another optional embodiment of this application, this embodiment 4 is mainly a refinement of step S13 in embodiment 1 above. Step S13 may include, but is not limited to, the following steps:

[0160] S131. Based on the transformer overload protection capacity threshold, the transformer real-time second power corresponding to the power demand, and the first power of the non-adjustable power unit, determine the first remaining available power boundary range.

[0161] S132. Based on the operating mode, determine the first initial target value of the first power of the adjustable power unit.

[0162] S133. Determine whether the first initial target value is within the range of the first remaining available boundary.

[0163] If yes, proceed to step S134; otherwise, proceed to step S137.

[0164] S134. Determine whether the first initial target value is within the range of the first chargeable / dischargeable power boundary.

[0165] If yes, proceed to step S135; otherwise, proceed to step S136.

[0166] S135. The value of the first power of the adjustable power unit is preferentially adjusted to the first initial target value.

[0167] S136. Select the first intermediate target value that is closest to the first initial target value from the range of the first rechargeable and dischargeable power boundary, and preferentially adjust the value of the first power of the adjustable power unit to the first intermediate target value.

[0168] For a detailed description of steps S131-S136, please refer to the relevant description of steps S131-S136 in Example 2, which will not be repeated here.

[0169] S137. Select the second intermediate target value that is closest to the first initial target value from the first remaining available boundary range.

[0170] The method for selecting the second intermediate target value can be found in the relevant description of step S1361, and will not be repeated here.

[0171] S138. Determine whether the second intermediate target value is within the range of the first rechargeable / dischargeable power boundary.

[0172] If yes, proceed to step S139; otherwise, proceed to step S1310.

[0173] S139. The value of the first power of the adjustable power unit is preferentially adjusted to the second intermediate target value.

[0174] S1310. Select the third intermediate target value that is closest to the second intermediate target value from the range of the first power boundary of the rechargeable and dischargeable power, and preferentially adjust the value of the first power of the adjustable power unit to the third intermediate target value.

[0175] The method for selecting the third intermediate target value can be found in the relevant description of step S1361, and will not be repeated here.

[0176] S1311. If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power, the adjustment ends.

[0177] After adjusting the first power, the apparent power of the photovoltaic-storage power station needs to be re-determined. If the re-determined apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer, the adjustment ends.

[0178] As another optional embodiment of this application, this embodiment 5 is mainly a refinement of step S13 in embodiment 1 above. Step S13, in addition to steps S131-S136 described in embodiment 2 or steps S131-S1311 described in embodiment 4, may also include, but is not limited to, the following steps:

[0179] S1312. Based on the value of the first power after adjustment of the adjustable power unit and the value of the first power of the non-adjustable power unit, determine the real-time first power of the transformer.

[0180] Step S1312 may include, but is not limited to, taking the sum of the adjusted first power value of the adjustable power unit and the first power value of the non-adjustable power unit as the value of the real-time first power of the transformer.

[0181] If the power demand is active power demand, then the first power is reactive power. Specifically, the sum of the adjusted reactive power value of the adjustable power unit and the reactive power value of the non-adjustable power unit is taken as the real-time reactive power value of the transformer.

[0182] If the power demand is reactive power demand, then the first power is active power. Specifically, the sum of the adjusted active power value of the adjustable power unit and the active power value of the non-adjustable power unit is taken as the real-time active power value of the transformer.

[0183] S1313. Based on the transformer overload protection capacity threshold, the transformer real-time first power, and the second power of the non-adjustable power unit, determine the second remaining available power boundary range, wherein the type of the second power of the non-adjustable power unit is different from the type of its first power.

[0184] If the power demand is an active power demand, then the first power is reactive power and the second power is active power; if the power demand is a reactive power demand, then the first power is active power and the second power is reactive power.

[0185] S1314. Based on the operating mode, determine the second initial target value of the second power of the adjustable power unit.

[0186] S1315. Determine whether the second initial target value is within the range of the second remaining available boundary.

[0187] If yes, proceed to step S1316; otherwise, proceed to step S1319.

[0188] S1316. Determine whether the second initial target value is within the range of the second chargeable / dischargeable power boundary.

[0189] The chargeable and dischargeable second power boundary range may include, but is not limited to: [-maximum chargeable second power, maximum dischargeable second power]. If the first power is reactive power, the second power is active power, and the chargeable and dischargeable second power boundary range may include, but is not limited to: [-maximum chargeable active power, maximum dischargeable active power].

[0190] If yes, proceed to step S1317; otherwise, proceed to step S1318.

[0191] S1317. The value of the second power of the adjustable power unit is preferentially adjusted to the second initial target value.

[0192] S1318. Select the fourth intermediate target value that is closest to the second initial target value from the range of the second rechargeable power boundary, and preferentially adjust the value of the second power of the adjustable power unit to the fourth intermediate target value.

[0193] The method for selecting the fourth intermediate target value can be found in the relevant description of step S1361, and will not be repeated here.

[0194] As another optional embodiment of this application, this embodiment 6 is mainly a refinement of step S1313 in embodiment 5 above. Step S1313 may include, but is not limited to, the following steps:

[0195] S13131. Determine the square root of the difference between the square of the overload protection capacity threshold of the transformer and the square of the real-time first power of the transformer.

[0196] S13132. The difference between the negative square root value and the value of the second power of the non-adjustable power unit is taken as the second boundary lower limit value, and the difference between the square root value and the value of the second power of the non-adjustable power unit is taken as the second boundary upper limit value. The range between the second boundary lower limit value and the second boundary upper limit value is determined as the second remaining available power boundary range.

[0197] Wherein, if the power demand is active power demand, the transformer real-time first power is the transformer real-time reactive power, and the non-adjustable power unit's second power is active power, the second remaining available power boundary range can be determined according to the following formula:

[0198]

[0199] Wherein, if the power demand is reactive power demand, the transformer's real-time first power is the transformer's real-time active power, and the non-adjustable power unit's second power is reactive power, the second remaining available power boundary range can be determined according to the following formula:

[0200]

[0201] As another optional embodiment of this application, this embodiment 7 is mainly a refinement of step S13 in embodiment 1 above. Step S13, in addition to steps S131-S136 described in embodiment 2 or steps S131-S1311 described in embodiment 4, may also include, but is not limited to, the following steps:

[0202] S1312. Based on the value of the first power after adjustment of the adjustable power unit and the value of the first power of the non-adjustable power unit, determine the real-time first power of the transformer.

[0203] S1313. Based on the transformer overload protection capacity threshold, the transformer real-time first power, and the second power of the non-adjustable power unit, determine the second remaining available power boundary range, wherein the type of the second power of the non-adjustable power unit is different from the type of its first power.

[0204] S1314. Based on the operating mode, determine the second initial target value of the second power of the adjustable power unit.

[0205] S1315. Determine whether the second initial target value is within the range of the second remaining available boundary.

[0206] If yes, proceed to step S1316; otherwise, proceed to step S1319.

[0207] S1316. Determine whether the second initial target value is within the range of the second chargeable / dischargeable power boundary.

[0208] If yes, proceed to step S1317; otherwise, proceed to step S1318.

[0209] S1317. The value of the second power of the adjustable power unit is preferentially adjusted to the second initial target value.

[0210] S1318. Select the fourth intermediate target value that is closest to the second initial target value from the range of the second rechargeable power boundary, and preferentially adjust the value of the second power of the adjustable power unit to the fourth intermediate target value.

[0211] For a detailed description of steps S1312-S1318, please refer to the relevant description of steps S1312-S1318 in Example 5, which will not be repeated here.

[0212] S1319. Select the fifth intermediate target value that is closest to the second initial target value from the range of the second remaining available boundary.

[0213] The method for selecting the fifth intermediate target value can be found in the relevant description of step S1361, and will not be repeated here.

[0214] S1320. Determine whether the fifth intermediate target value is within the range of the chargeable / dischargeable second power boundary;

[0215] If yes, proceed to step S1321; otherwise, proceed to step S1322.

[0216] S1321. The value of the second power of the adjustable power unit is preferentially adjusted to the fifth intermediate target value.

[0217] S1322. Select the sixth intermediate target value that is closest to the fifth intermediate target value from the range of the second power boundary of the rechargeable and dischargeable power, and preferentially adjust the value of the second power of the adjustable power unit to the sixth intermediate target value.

[0218] The method for selecting the sixth intermediate target value can be found in the relevant description of step S1361, and will not be repeated here.

[0219] As another optional embodiment of this application, refer to Figure 3 This is a flowchart illustrating a power allocation method for a photovoltaic-storage power station provided in Embodiment 8 of this application. This embodiment is mainly a refinement of the power allocation method for a photovoltaic-storage power station described in Embodiment 1 above, such as... Figure 3 As shown, the method may include, but is not limited to, the following steps:

[0220] Step S21: Obtain the apparent power of the photovoltaic-storage power station.

[0221] For a detailed description of step S21, please refer to the relevant description of step S11 in Example 1, which will not be repeated here.

[0222] Step S22: If the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, and if the photovoltaic-storage power station has multiple operating modes, sort the operating modes in descending order of priority.

[0223] Step S23: Select the operating mode that is ranked first among the various operating modes and has not participated in determining the power demand. Determine the power demand of the photovoltaic-storage power station based on the selected operating mode.

[0224] For example, multiple operating modes include primary frequency regulation mode and AVC mode. Initially, neither primary frequency regulation mode nor AVC mode has participated in determining power demand. If the priority of primary frequency regulation mode is higher than that of AVC mode, then the primary frequency regulation mode, which is ranked highest and has not participated in determining power demand, is selected from the primary frequency regulation mode and AVC mode. Based on the selected primary frequency regulation mode, the power demand of the photovoltaic-storage power station is determined. Next, the AVC mode, which is ranked highest and has not participated in determining power demand, is selected from the primary frequency regulation mode and AVC mode. Based on the selected AVC mode, the power demand of the photovoltaic-storage power station is determined.

[0225] Steps S22-S23 are a specific implementation of step S12 in Example 1.

[0226] Step S24: Based on the power demand, prioritize adjusting the first power of the adjustable power unit in the photovoltaic-storage power station.

[0227] Wherein, if the power demand is an active power demand, the first power is reactive power; if the power demand is a reactive power demand, the first power is active power.

[0228] For a detailed description of step S24, please refer to the relevant description of step S13 in the foregoing embodiments, which will not be repeated here.

[0229] Step S25: Determine whether the apparent power of the photovoltaic-storage power station after adjusting the first power exceeds the overload protection capacity threshold of the transformer.

[0230] After adjusting the first power, it is necessary to redetermine the apparent power of the photovoltaic-storage power station and determine whether the redetermined apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer.

[0231] If yes, return to step S23; otherwise, proceed to step S26.

[0232] Step S26: End adjustment.

[0233] Steps S24-S26 are a specific implementation of step S13 in Example 1.

[0234] In this embodiment, when the photovoltaic-storage power station may operate in multiple operating modes at the same time, by obtaining the apparent power of the photovoltaic-storage power station, if the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, the operating modes can be sorted, and the operating mode with the highest priority can be selected first. Based on the selected operating mode with the highest priority, the power demand of the photovoltaic-storage power station is determined. Based on the power demand, the first power of the photovoltaic-storage power station is adjusted first to realize the redistribution between the active power and reactive power of the photovoltaic-storage power station. This can ensure the power demand of the photovoltaic-storage power station in the high-priority operating mode while protecting the transformer from overload.

[0235] As another optional embodiment of this application, refer to Figure 4 This is a flowchart illustrating a power allocation method for a photovoltaic-storage power station provided in Embodiment 9 of this application. This embodiment is mainly a refinement of the power allocation method for a photovoltaic-storage power station described in Embodiment 1 above, such as... Figure 4 As shown, the method may include, but is not limited to, the following steps:

[0236] Step S31: Obtain the apparent power of the photovoltaic-storage power station.

[0237] Step S32: If the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, determine the power demand of the photovoltaic-storage power station according to the operating mode of the photovoltaic-storage power station.

[0238] For a detailed description of steps S31-S32, please refer to the relevant description of steps S11-S12 in Example 1, which will not be repeated here.

[0239] Step S33: If there are multiple adjustable power units, sort them in order of priority from high to low.

[0240] Step S34: Select the adjustable power unit that is ranked first and has not been adjusted from all the adjustable power units, and prioritize adjusting the first power of the adjustable power unit that is ranked first and has not been adjusted.

[0241] For example, multiple adjustable power units include photovoltaic (PV) systems and energy storage systems. Initially, both PV and energy storage systems are unregulated adjustable power units. If the priority of the PV system is higher than that of the energy storage system, the PV system, which is ranked highest and has not yet been regulated, is selected from the PV and energy storage systems, and its power is adjusted first (e.g., first power; or, first power and second power). After the PV system has been regulated, the unregulated adjustable power units among the multiple adjustable power units become only the energy storage system. The energy storage system, which is ranked highest and has not yet been regulated, is then selected from the PV and energy storage systems, and its power is adjusted first.

[0242] Step S35: Determine whether the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer after adjusting the first power of the first adjustable power unit that is ranked first and has not participated in the adjustment.

[0243] It should be noted that after adjusting the first power of the adjustable power unit that is ranked first and has not been adjusted before, it is necessary to redetermine the apparent power of the photovoltaic-storage power station and determine whether the redetermined apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer.

[0244] If not, proceed to step S36.

[0245] Step S36: End adjustment.

[0246] Steps S33-S36 are a specific implementation of step S13 in Example 1.

[0247] In this embodiment, by obtaining the apparent power of the photovoltaic-storage power station, if the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, the power demand of the photovoltaic-storage power station is determined according to the operating mode of the photovoltaic-storage power station. If there are multiple adjustable power units, the first power of the adjustable power unit with the higher priority is adjusted according to the priority of the adjustable power units until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer. This achieves the redistribution of active and reactive power between the photovoltaic-storage power station, which can ensure the power demand of the photovoltaic-storage power station while protecting the transformer from overload.

[0248] As another optional embodiment of this application, refer to Figure 5 This is a flowchart illustrating a power allocation method for a photovoltaic-storage power station provided in Embodiment 10 of this application. This embodiment is mainly a refinement of the power allocation method for a photovoltaic-storage power station described in Embodiment 1 above, such as... Figure 5 As shown, in Figure 4Based on the power allocation method for the photovoltaic-storage power station shown, if adjusting the first power of the first adjustable power unit that is ranked first and has not been adjusted before determines whether the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, the following steps may be included, but are not limited to:

[0249] Step S37: Adjust the second power of the adjustable power unit that is ranked first and has not been adjusted before. The second power is of a different type than the first power.

[0250] If the first power is active power, then the second power is reactive power; if the first power is reactive power, then the second power is active power.

[0251] Step S38: Determine whether the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer after adjusting the second power of the first-ranked adjustable power unit that has not been adjusted.

[0252] It should be noted that after adjusting the second power of the adjustable power unit that is ranked first and has not been adjusted before, it is necessary to redetermine the apparent power of the photovoltaic-storage power station and determine whether the redetermined apparent power of the photovoltaic-storage power station exceeds the transformer overload protection capacity threshold.

[0253] If yes, proceed to step S34; otherwise, return to step S36.

[0254] Steps S33-S38 are a specific implementation of step S13 in Example 1.

[0255] In this embodiment, by obtaining the apparent power of the photovoltaic-storage power station, if the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, the power demand of the photovoltaic-storage power station is determined according to the operating mode of the photovoltaic-storage power station. If there are multiple adjustable power units, the first and second power of the adjustable power units with higher priority are adjusted according to their priority until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer. This achieves a redistribution of active and reactive power between the photovoltaic-storage power station, ensuring the power demand of the photovoltaic-storage power station while protecting the transformer from overload.

[0256] As another optional embodiment of this application, refer to Figure 6 This is a flowchart illustrating a power allocation method for a photovoltaic-storage power station provided in Embodiment 11 of this application. This embodiment is mainly a refinement of the power allocation method for a photovoltaic-storage power station described in Embodiment 1 above, such as... Figure 6 As shown, the method may include, but is not limited to, the following steps:

[0257] Step S41: Obtain the apparent power of the photovoltaic-storage power station.

[0258] Step S42: If the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, determine the power demand of the photovoltaic-storage power station according to the operating mode of the photovoltaic-storage power station.

[0259] For a detailed description of steps S41-S42, please refer to the relevant description of steps S11-S12 in Example 1, which will not be repeated here.

[0260] Step S43: If there are multiple adjustable power units, sort them in order of priority from high to low.

[0261] Step S44: Select the adjustable power unit that is ranked first and has not participated in the first power adjustment from all the adjustable power units, and prioritize adjusting the first power of the adjustable power unit that is ranked first and has not participated in the first power adjustment.

[0262] For example, multiple adjustable power units include photovoltaic (PV) systems and energy storage systems. Initially, both the PV and energy storage systems are adjustable power units that have not participated in the first power regulation. If the priority of the PV system is higher than that of the energy storage system, then the highest-ranking adjustable power unit that has not participated in the first power regulation (i.e., the PV system) is selected, and its first power is adjusted first. After the PV system has participated in the first power regulation, the only adjustable power unit that has not participated in the first power regulation among the multiple adjustable power units becomes the energy storage system. Therefore, the highest-ranking adjustable power unit that has not participated in the first power regulation (i.e., the energy storage system) is selected from both the PV and energy storage systems.

[0263] Step S45: Determine whether the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer after adjusting the first power of the first adjustable power unit that is ranked first and has not participated in the first power adjustment.

[0264] It should be noted that after adjusting the first power of the adjustable power unit that is ranked first and has not participated in the first power adjustment, it is necessary to redetermine the apparent power of the photovoltaic-storage power station and determine whether the redetermined apparent power of the photovoltaic-storage power station exceeds the transformer overload protection capacity threshold.

[0265] If not, proceed to step S46; if yes, proceed to step S47.

[0266] Step S46: End adjustment.

[0267] Step S47: Determine whether there are any adjustable power units that have not participated in the first power regulation.

[0268] If so, return to step S44.

[0269] Steps S43-S47 are a specific implementation of step S13 in Example 1.

[0270] In this embodiment, by obtaining the apparent power of the photovoltaic-storage power station, if the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, the power demand of the photovoltaic-storage power station is determined according to the operating mode of the photovoltaic-storage power station. If there are multiple adjustable power units, the first power of the adjustable power unit with the highest priority is adjusted in sequence according to the priority of the adjustable power units until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer. This realizes the redistribution between the active power and reactive power of the photovoltaic-storage power station, which can ensure the power demand of the photovoltaic-storage power station while protecting the transformer from overload.

[0271] As another optional embodiment of this application, refer to Figure 7 This is a flowchart illustrating a power allocation method for a photovoltaic-storage power station provided in Embodiment 12 of this application. This embodiment is mainly a refinement of the power allocation method for a photovoltaic-storage power station described in Embodiment 1 above, such as... Figure 7 As shown, in Figure 6 Based on the power allocation method for the photovoltaic-storage power station shown, if the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer after adjusting the first power of the adjustable power unit that is ranked first and has not participated in the first power adjustment, and there is no adjustable power unit that has not participated in the first power adjustment, the method may further include, but is not limited to, the following steps:

[0272] Step S48: Select the adjustable power unit that is ranked first and has not participated in the second power adjustment from all the adjustable power units, and prioritize adjusting the second power of the adjustable power unit that is ranked first and has not participated in the second power adjustment.

[0273] For example, in a scenario with multiple adjustable power units including photovoltaic (PV) systems and energy storage systems, if both the PV and energy storage systems have participated in the first power regulation but have not yet participated in the second power regulation, then the PV system (ranked highest and not yet involved in the second power regulation) is selected and its second power regulation is prioritized. After the PV system has participated in the second power regulation, the only adjustable power unit remaining that has not participated in the second power regulation becomes the energy storage system. In this case, the energy storage system (ranked highest and not yet involved in the second power regulation) is selected from both the PV and energy storage systems.

[0274] Step S49: Determine whether the apparent power of the photovoltaic-storage power station exceeds the transformer overload protection capacity threshold after adjusting the second power of the adjustable power unit that ranks first and has not participated in the second power adjustment.

[0275] It should be noted that after adjusting the second power of the adjustable power unit that is ranked first and has not participated in the second power adjustment, it is necessary to redetermine the apparent power of the photovoltaic-storage power station and determine whether the redetermined apparent power of the photovoltaic-storage power station exceeds the transformer overload protection capacity threshold.

[0276] If not, return to step S46; if yes, proceed to step S410.

[0277] Step S410: Determine whether there are any adjustable power units that have not participated in the second power regulation.

[0278] If so, return to step S48.

[0279] Steps S43-S410 are a specific implementation of step S13 in Example 1.

[0280] In this embodiment, by obtaining the apparent power of the photovoltaic-storage power station, if the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, the power demand of the photovoltaic-storage power station is determined according to the operating mode of the photovoltaic-storage power station. If there are multiple adjustable power units, the first power of the adjustable power unit with the highest priority is adjusted in sequence according to the priority of the adjustable power units. If the apparent power of the photovoltaic-storage power station still exceeds the overload protection capacity threshold of the transformer after adjusting the first power of various adjustable power units, the second power of the adjustable power unit with the highest priority is adjusted in sequence according to the priority of the adjustable power units until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer. This achieves the redistribution of active and reactive power between the photovoltaic-storage power station, which can ensure the power demand of the photovoltaic-storage power station while protecting the transformer from overload.

[0281] The power distribution device for a photovoltaic power station provided in the embodiments of this application is described below. The power distribution device for a photovoltaic power station described below can be referred to in correspondence with the power distribution method for a photovoltaic power station described above.

[0282] Please see Figure 8 The power distribution device for a photovoltaic-storage power station includes: an acquisition module 100, a determination module 200, and an adjustment module 300.

[0283] Module 100 is used to obtain the apparent power of the photovoltaic-storage power station.

[0284] The determination module 200 is used to determine the power demand of the photovoltaic-storage power station based on the operating mode of the photovoltaic-storage power station if the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer.

[0285] The adjustment module 300 is used to adjust the first power of the adjustable power unit in the photovoltaic-storage power station based on the power demand, until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer. If the power demand is an active power demand, the first power is reactive power; if the power demand is a reactive power demand, the first power is active power.

[0286] If the photovoltaic-storage power station has multiple operating modes, the determining module 200 can specifically be used for:

[0287] The operating modes are sorted in descending order of priority.

[0288] Select the operating mode that ranks highest among the various operating modes and has not participated in determining the power demand, and determine the power demand of the photovoltaic-storage power station based on the selected operating mode;

[0289] The adjustment module 300 can be specifically used for:

[0290] Based on the power requirement, the first power of the adjustable power unit in the photovoltaic-storage power station is adjusted first.

[0291] If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power, the adjustment ends.

[0292] If the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer after adjusting the first power, return to the step of selecting the operating mode that is ranked first among the various operating modes and has not participated in determining the power demand.

[0293] In this embodiment, the adjustment module 300 can be specifically used for:

[0294] Based on the transformer overload protection capacity threshold, the transformer real-time second power corresponding to the power demand, and the first power of the non-adjustable power unit, the first remaining available power boundary range is determined.

[0295] Based on the operating mode, a first initial target value for the first power of the adjustable power unit is determined;

[0296] If the first initial target value is within the first remaining available boundary range, determine whether the first initial target value is within the chargeable / dischargeable first power boundary range;

[0297] If so, the value of the first power of the adjustable power unit shall be adjusted to the first initial target value first.

[0298] If not, select the first intermediate target value that is closest to the first initial target value from the range of the first rechargeable and dischargeable power boundary, and preferentially adjust the value of the first power of the adjustable power unit to the first intermediate target value;

[0299] If the first initial target value is not within the first remaining available boundary range, select the second intermediate target value that is closest to the first initial target value from within the first remaining available boundary range;

[0300] Determine whether the second intermediate target value is within the range of the first chargeable / dischargeable power boundary;

[0301] If so, the value of the first power of the adjustable power unit shall be adjusted to the second intermediate target value first;

[0302] If not, select the third intermediate target value that is closest to the second intermediate target value from the range of the first power boundary of the rechargeable and dischargeable power, and preferentially adjust the value of the first power of the adjustable power unit to the third intermediate target value;

[0303] If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power, the adjustment ends.

[0304] In this embodiment, the process by which the adjustment module 300 determines the first remaining available power boundary range based on the transformer overload protection capacity threshold, the real-time second power of the transformer corresponding to the power demand, and the first power of the non-adjustable power unit can specifically include:

[0305] Determine the square root of the difference between the square of the overload protection capacity threshold of the transformer and the square of the real-time power of the transformer;

[0306] The difference between the negative square root value and the value of the first power of the non-adjustable power unit is taken as the first boundary lower limit value, the difference between the square root value and the value of the first power of the non-adjustable power unit is taken as the first boundary upper limit value, and the range between the first boundary lower limit value and the second boundary upper limit value is determined as the first remaining available power boundary range.

[0307] In this embodiment, the adjustment module 300 can also be used for:

[0308] If the apparent power of the photovoltaic-storage power station still exceeds the overload protection capacity threshold of the transformer after adjusting the first power, the real-time first power of the transformer is determined based on the value of the first power after adjustment of the adjustable power unit and the value of the first power of the non-adjustable power unit.

[0309] Based on the transformer overload protection capacity threshold, the transformer real-time first power, and the second power of the non-adjustable power unit, a second remaining available power boundary range is determined, wherein the type of the second power of the non-adjustable power unit is different from the type of its first power;

[0310] Based on the operating mode, a second initial target value for the second power of the adjustable power unit is determined;

[0311] If the second initial target value is within the range of the second remaining available boundary, determine whether the second initial target value is within the range of the second chargeable / dischargeable power boundary;

[0312] If so, the value of the second power of the adjustable power unit shall be adjusted to the second initial target value first;

[0313] If not, select the fourth intermediate target value that is closest to the second initial target value from the range of the second rechargeable power boundary, and preferentially adjust the value of the second power of the adjustable power unit to the fourth intermediate target value;

[0314] If the second initial target value is not within the second remaining available boundary range, select the fifth intermediate target value that is closest to the second initial target value from within the second remaining available boundary range;

[0315] Determine whether the fifth intermediate target value is within the range of the chargeable / dischargeable second power boundary;

[0316] If so, the value of the second power of the adjustable power unit shall be adjusted to the fifth intermediate target value first;

[0317] If not, select the sixth intermediate target value that is closest to the fifth intermediate target value from the range of the second rechargeable power boundary, and preferentially adjust the value of the second power of the adjustable power unit to the sixth intermediate target value.

[0318] In this embodiment, the process by which the adjustment module 300 determines the second remaining available power boundary range based on the transformer overload protection capacity threshold, the transformer's real-time first power, and the second power of the non-adjustable power unit may specifically include:

[0319] Determine the square root of the difference between the square of the transformer overload protection capacity threshold and the square of the transformer's real-time first power.

[0320] The difference between the negative square root value and the value of the second power of the non-adjustable power unit is taken as the second boundary lower limit value, the difference between the square root value and the value of the second power of the non-adjustable power unit is taken as the second boundary upper limit value, and the range between the second boundary lower limit value and the second boundary lower limit value is determined as the second remaining available power boundary range.

[0321] In this embodiment, if there are multiple adjustable power units, the adjustment module 300 can be specifically used for:

[0322] The adjustable power units are sorted in descending order of priority.

[0323] Select the adjustable power unit that is ranked first and has not been adjusted from among the adjustable power units, and preferentially adjust the first power of the adjustable power unit that is ranked first and has not been adjusted.

[0324] If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power of the first adjustable power unit that is ranked first and has not been adjusted before, the adjustment ends.

[0325] If the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer after adjusting the first power of the first adjustable power unit that has not been adjusted, the second power of the first adjustable power unit that has not been adjusted is adjusted, and the second power is of a different type than the first power.

[0326] If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the second power of the first adjustable power unit that has not been adjusted before, the adjustment ends.

[0327] If the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer after adjusting the second power of the adjustable power unit that is ranked first and has not been adjusted, the process returns to the step of selecting the adjustable power unit that is ranked first and has not been adjusted from among the adjustable power units.

[0328] In this embodiment, if there are multiple adjustable power units, the adjustment module 300 can be specifically used for:

[0329] The adjustable power units are sorted in descending order of priority.

[0330] Select the adjustable power unit that is ranked first and has not participated in the first power adjustment from among the adjustable power units, and preferentially adjust the first power of the adjustable power unit that is ranked first and has not participated in the first power adjustment.

[0331] If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power of the adjustable power unit that is ranked first and has not participated in the first power adjustment, the adjustment ends.

[0332] If the apparent power of the photovoltaic-storage power station exceeds the transformer overload protection capacity threshold after adjusting the first power of the adjustable power unit that is ranked first and has not participated in the first power adjustment, and there are still adjustable power units that have not participated in the first power adjustment, then return to the step of selecting the adjustable power unit that is ranked first and has not participated in the first power adjustment from each of the adjustable power units.

[0333] If the apparent power of the photovoltaic-storage power station exceeds the transformer overload protection capacity threshold after adjusting the first power of the adjustable power unit that is ranked first and has not participated in the first power adjustment, and there is no adjustable power unit that has not participated in the first power adjustment, then select the adjustable power unit that is ranked first and has not participated in the second power adjustment from among the adjustable power units, and prioritize adjusting the second power of the adjustable power unit that is ranked first and has not participated in the second power adjustment.

[0334] If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the second power of the adjustable power unit that is ranked first and has not participated in the second power adjustment, the adjustment ends.

[0335] If, after adjusting the second power of the adjustable power unit that ranks first and has not participated in the second power adjustment, the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, and there are still adjustable power units that have not participated in the second power adjustment, then the step of selecting the adjustable power unit that ranks first and has not participated in the second power adjustment from among the adjustable power units is returned to be executed.

[0336] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0337] Each embodiment in this specification focuses on the differences from other embodiments. For the same or similar parts between the embodiments, please refer to each other.

[0338] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A power allocation method for a photovoltaic-storage power station, characterized in that, include: Obtain the apparent power of the photovoltaic and energy storage power station; If the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, the power demand of the photovoltaic-storage power station shall be determined according to the operating mode of the photovoltaic-storage power station. Based on the power demand, the first power of the adjustable power unit in the photovoltaic-storage power station is adjusted first until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer. Wherein, if the power demand is an active power demand, the first power is reactive power; if the power demand is a reactive power demand, the first power is active power. If the photovoltaic-storage power station has multiple operating modes, determining the power requirement of the photovoltaic-storage power station based on its operating mode includes: The operating modes are sorted in descending order of priority; Select the operating mode that ranks highest among the various operating modes and has not participated in determining power demand, and determine the power demand of the photovoltaic-storage power station based on the selected operating mode.

2. The method according to claim 1, characterized in that, The step of prioritizing the adjustment of the first power of the adjustable power unit in the photovoltaic-storage power station based on the power demand until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer includes: Based on the power requirement, the first power of the adjustable power unit in the photovoltaic-storage power station is adjusted first. If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power, the adjustment ends. If the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer after adjusting the first power, return to the step of selecting the operating mode that is ranked first among the various operating modes and has not participated in determining the power demand.

3. The method according to claim 1, characterized in that, Based on the power demand, the first power of the adjustable power unit in the photovoltaic-storage power station is preferentially adjusted until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer, including: Based on the transformer overload protection capacity threshold, the transformer real-time second power corresponding to the power demand, and the first power of the non-adjustable power unit, the first remaining available power boundary range is determined. Based on the operating mode, a first initial target value for the first power of the adjustable power unit is determined; If the first initial target value is within the first remaining available boundary range, determine whether the first initial target value is within the chargeable / dischargeable first power boundary range; If so, the value of the first power of the adjustable power unit shall be adjusted to the first initial target value first. If not, select the first intermediate target value that is closest to the first initial target value from the range of the first rechargeable and dischargeable power boundary, and preferentially adjust the value of the first power of the adjustable power unit to the first intermediate target value; If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power, the adjustment ends.

4. The method according to claim 3, characterized in that, The method further includes: If the first initial target value is not within the first remaining available boundary range, select the second intermediate target value that is closest to the first initial target value from within the first remaining available boundary range; Determine whether the second intermediate target value is within the range of the first chargeable / dischargeable power boundary; If so, the value of the first power of the adjustable power unit shall be adjusted to the second intermediate target value first; If not, select the third intermediate target value that is closest to the second intermediate target value from the range of the first power boundary of the rechargeable and dischargeable power, and preferentially adjust the value of the first power of the adjustable power unit to the third intermediate target value; If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power, the adjustment ends.

5. The method according to claim 3, characterized in that, Based on the transformer overload protection capacity threshold, the transformer's real-time second power corresponding to the power demand, and the first power of the non-adjustable power unit, the first remaining available power boundary range is determined, including: Determine the square root of the difference between the square of the overload protection capacity threshold of the transformer and the square of the real-time second power of the transformer; The difference between the negative square root value and the value of the first power of the non-adjustable power unit is used as the first boundary lower limit value, and the difference between the square root value and the value of the first power of the non-adjustable power unit is used as the first boundary upper limit value. The range between the first boundary lower limit value and the first boundary upper limit value is determined as the first remaining available power boundary range.

6. The method according to claim 3 or 4, characterized in that, The method further includes: If the apparent power of the photovoltaic-storage power station still exceeds the overload protection capacity threshold of the transformer after adjusting the first power, the real-time first power of the transformer is determined based on the value of the first power after adjustment of the adjustable power unit and the value of the first power of the non-adjustable power unit. Based on the transformer overload protection capacity threshold, the transformer real-time first power, and the second power of the non-adjustable power unit, a second remaining available power boundary range is determined, wherein the type of the second power of the non-adjustable power unit is different from the type of its first power; Based on the operating mode, a second initial target value for the second power of the adjustable power unit is determined; If the second initial target value is within the range of the second remaining available boundary, determine whether the second initial target value is within the range of the second chargeable / dischargeable power boundary; If so, the value of the second power of the adjustable power unit shall be adjusted to the second initial target value first; If not, select the fourth intermediate target value that is closest to the second initial target value from the range of the second rechargeable power boundary, and preferentially adjust the value of the second power of the adjustable power unit to the fourth intermediate target value.

7. The method according to claim 6, characterized in that, The method further includes: If the second initial target value is not within the second remaining available boundary range, select the fifth intermediate target value that is closest to the second initial target value from within the second remaining available boundary range; Determine whether the fifth intermediate target value is within the range of the chargeable / dischargeable second power boundary; If so, the value of the second power of the adjustable power unit shall be adjusted to the fifth intermediate target value first; If not, select the sixth intermediate target value that is closest to the fifth intermediate target value from the range of the second rechargeable power boundary, and preferentially adjust the value of the second power of the adjustable power unit to the sixth intermediate target value.

8. The method according to claim 6, characterized in that, Based on the transformer overload protection capacity threshold, the transformer's real-time first power, and the second power of the non-adjustable power unit, the second remaining available power boundary range is determined, including: Determine the square root of the difference between the square of the transformer overload protection capacity threshold and the square of the transformer's real-time first power. The difference between the negative square root value and the value of the second power of the non-adjustable power unit is taken as the second boundary lower limit value, and the difference between the square root value and the value of the second power of the non-adjustable power unit is taken as the second boundary upper limit value. The range between the second boundary lower limit value and the second boundary upper limit value is determined as the second remaining available power boundary range.

9. The method according to claim 1, characterized in that, If there are multiple adjustable power units, based on the power requirement, the first power of the adjustable power unit in the photovoltaic-storage power station is adjusted first until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer, including: The adjustable power units are sorted in descending order of priority. Select the adjustable power unit that is ranked first and has not been adjusted from among the adjustable power units, and preferentially adjust the first power of the adjustable power unit that is ranked first and has not been adjusted. If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power of the first adjustable power unit that is ranked first and has not been adjusted, the adjustment ends.

10. The method according to claim 9, characterized in that, The method further includes: If the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer after adjusting the first power of the first adjustable power unit that has not been adjusted, the second power of the first adjustable power unit that has not been adjusted is adjusted, and the second power is of a different type than the first power. If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the second power of the first adjustable power unit that has not been adjusted before, the adjustment ends. If the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer after adjusting the second power of the adjustable power unit that is ranked first and has not been adjusted, the process returns to the step of selecting the adjustable power unit that is ranked first and has not been adjusted from among the adjustable power units.

11. The method according to claim 1, characterized in that, If there are multiple adjustable power units, based on the power requirement, the first power of the adjustable power unit in the photovoltaic-storage power station is adjusted first until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer, including: The adjustable power units are sorted in descending order of priority. Select the adjustable power unit that is ranked first and has not participated in the first power adjustment from among the adjustable power units, and preferentially adjust the first power of the adjustable power unit that is ranked first and has not participated in the first power adjustment. If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the first power of the adjustable power unit that is ranked first and has not participated in the first power adjustment, the adjustment ends. If, after adjusting the first power of the adjustable power unit that ranks first and has not participated in the first power adjustment, the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, and there are still adjustable power units that have not participated in the first power adjustment, then the step of selecting the adjustable power unit that ranks first and has not participated in the first power adjustment from among the adjustable power units is returned to be executed.

12. The method according to claim 11, characterized in that, The method further includes: If the apparent power of the photovoltaic-storage power station exceeds the transformer overload protection capacity threshold after adjusting the first power of the adjustable power unit that is ranked first and has not participated in the first power adjustment, and there is no adjustable power unit that has not participated in the first power adjustment, then select the adjustable power unit that is ranked first and has not participated in the second power adjustment from among the adjustable power units, and prioritize adjusting the second power of the adjustable power unit that is ranked first and has not participated in the second power adjustment. If the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer after adjusting the second power of the adjustable power unit that is ranked first and has not participated in the second power adjustment, the adjustment ends. If, after adjusting the second power of the adjustable power unit that ranks first and has not participated in the second power adjustment, the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer, and there are still adjustable power units that have not participated in the second power adjustment, then the step of selecting the adjustable power unit that ranks first and has not participated in the second power adjustment from among the adjustable power units is returned to be executed.

13. A power distribution device for a photovoltaic-storage power station, characterized in that, include: The acquisition module is used to obtain the apparent power of the photovoltaic-storage power station; The determination module is used to determine the power demand of the photovoltaic-storage power station based on the operating mode of the photovoltaic-storage power station if the apparent power of the photovoltaic-storage power station exceeds the overload protection capacity threshold of the transformer. The adjustment module is used to adjust the first power of the adjustable power unit in the photovoltaic-storage power station based on the power demand, until the apparent power of the photovoltaic-storage power station does not exceed the overload protection capacity threshold of the transformer. If the power demand is an active power demand, the first power is reactive power. If the power demand is a reactive power demand, the first power is active power. If the photovoltaic-storage power station has multiple operating modes, the determining module determines the power requirement of the photovoltaic-storage power station based on the operating mode, specifically for: The operating modes are sorted in descending order of priority; the operating mode that is ranked first and has not participated in determining the power demand is selected from the operating modes, and the power demand of the photovoltaic-storage power station is determined based on the selected operating mode.

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