Power control method, device, power system, storage medium and program product of a power system

Abstract

The present application discloses a power control method, device, power system, storage medium and program product for a power system, belonging to the field of power systems. The power control method for the power system includes: a first control module obtains an expected value of the DC-side power response corresponding to a target power conversion device among at least one power conversion device; determines a target AC electrical signal corresponding to the target power conversion device according to the expected value of the DC-side power response corresponding to the target power conversion device, the actual electrical signal at the AC coupling point, and a first electrical signal reference value of the AC coupling point; and controls the working state of the target power conversion device based on the target AC electrical signal to adjust the power supply relationship among the power conversion devices. The power control method for the power system of the present application can enable the power conversion devices to reach a balanced state.

Description

Technical Field

[0001] This application belongs to the field of power systems, and particularly relates to a power control method, device, power system, storage medium, and program product for a power system. Background Art

[0002] With the development of renewable energy technologies, photovoltaic devices, energy storage devices, photovoltaic-energy storage devices, and AC / DC charging devices have been widely used. However, with the increase in the types and quantities of controllable devices, both the degrees of freedom and constraints of system control have increased accordingly, and the complexity of energy scheduling for them has also increased exponentially. In related technologies, for off-grid operation scenarios, the commonly used energy scheduling method mainly involves enumerating each scenario to determine the operating states of current devices, and based on this, power distribution is performed; this method requires listing all scenarios, has low energy utilization efficiency, low control efficiency, and high complexity, is difficult to cover various boundary conditions and does not have real-time performance, affects the scheduling effect, and affects the accuracy and economy of energy scheduling in the off-grid operation scenario of the power system. Summary of the Invention

[0003] This application aims to solve at least one of the technical problems existing in the prior art. For this purpose, this application proposes a power control method, device, power system, storage medium, and program product for a power system, enabling each power conversion device to reach a balanced state.

[0004] In a first aspect, this application provides a power control method for a power system. The power system includes at least one power conversion device and a first control module electrically connected to the power conversion device. Each power conversion device is respectively connected to an AC coupling point; each power conversion device includes a first converter and at least one DC module, and the power conversion device is used to connect to an external device through the AC coupling point; each DC module in the same power conversion device is respectively connected to the first converter through a DC coupling point; the method includes:

[0005] The first control module obtains the expected value of the DC-side power response corresponding to the target power conversion device among the at least one power conversion device;

[0006] Based on the expected value of the DC-side power response corresponding to the target power conversion device, the actual electrical signal of the AC coupling point, and the first electrical signal reference value of the AC coupling point, determine the target AC electrical signal corresponding to the target power conversion device;

[0007] Based on the target AC electrical signal, control the operating state of the target power conversion device to adjust the power supply relationship between the power conversion devices.

[0008] According to the power control method of the power system of the present application, by using the expected value of the DC-side power response corresponding to the target power conversion device and the first electrical signal reference value of the AC coupling point, the target AC electrical signal for adjusting the first converter of the power conversion device is determined to control the first converter, so as to adjust the power supply relationship between the power conversion devices, and make the power conversion devices reach a balanced state.

[0009] In a second aspect, the present application provides a power control device for a power system. The power system includes at least one power conversion device, and each power conversion device is respectively connected to an AC coupling point; each power conversion device includes a first converter and at least one DC module, and the power conversion device is used to be connected to an external device through the AC coupling point; in the same power conversion device, each DC module is respectively connected to the first converter through a DC coupling point; the device includes:

[0010] A first processing module, configured to obtain the expected value of the DC-side power response corresponding to the target power conversion device in the at least one power conversion device;

[0011] A second processing module, configured to determine the target AC electrical signal corresponding to the target power conversion device according to the expected value of the DC-side power response corresponding to the target power conversion device, the actual electrical signal of the AC coupling point, and the first electrical signal reference value of the AC coupling point;

[0012] A third processing module, configured to control the operating state of the target power conversion device based on the target AC electrical signal, so as to adjust the power supply relationship between the power conversion devices.

[0013] According to the power control device of the power system of the present application, by using the expected value of the DC-side power response corresponding to the target power conversion device and the first electrical signal reference value of the AC coupling point, the target AC electrical signal for adjusting the first converter of the power conversion device is determined to control the first converter, so as to adjust the power supply relationship between the power conversion devices, and make the power conversion devices reach a balanced state.

[0014] In a third aspect, the present application provides a power system, including:

[0015] A first control module;

[0016] At least one power conversion device, each power conversion device is respectively connected to an AC coupling point; each power conversion device includes a first converter and at least one DC module, the power conversion device is used to be connected to an external device through the AC coupling point; each DC module is respectively connected to the first converter through a DC coupling point, and the first control module is respectively connected to each first converter;

[0017] The power system operates according to the power control method of the power system as described in the first aspect.

[0018] In a fourth aspect, the present application provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the power control method of the power system as described in the first aspect above.

[0019] In a fifth aspect, the present application provides a computer program product, including a computer program. When the computer program is executed by a processor, it implements the power control method of the power system as described in the first aspect above. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, where:

[0021] Figure 1 FIG. 15 is one of the schematic flowcharts of the power control method of the power system provided by the embodiment of the present application;

[0022] Figure 2 FIG. 19 is one of the schematic structural diagrams of the power system provided by the embodiment of the present application;

[0023] Figure 3 FIG. 23 is another schematic structural diagram of the power system provided by the embodiment of the present application;

[0024] Figure 4 FIG. 27 is still another schematic structural diagram of the power system provided by the embodiment of the present application;

[0025] Figure 5 FIG. 31 is another schematic flowchart of the power control method of the power system provided by the embodiment of the present application;

[0026] Figure 6 FIG. 35 is still another schematic flowchart of the power control method of the power system provided by the embodiment of the present application;

[0027] Figure 7 FIG. 39 is still another schematic flowchart of the power control method of the power system provided by the embodiment of the present application;

[0028] Figure 8 FIG. 43 is another schematic structural diagram of the power system provided by the embodiment of the present application;

[0029] Figure 9 FIG. 47 is one of the schematic diagrams of the results of the power control method of the power system provided by the embodiment of the present application;

[0030] Figure 10 FIG. 51 is still another schematic diagram of the results of the power control method of the power system provided by the embodiment of the present application;

[0031] Figure 11 It is the third schematic diagram of the results of the power control method for the power system provided by the embodiment of the present application;

[0032] Figure 12 It is the fourth schematic diagram of the results of the power control method for the power system provided by the embodiment of the present application;

[0033] Figure 13 It is the fifth schematic diagram of the results of the power control method for the power system provided by the embodiment of the present application;

[0034] Figure 14 It is the sixth schematic diagram of the results of the power control method for the power system provided by the embodiment of the present application;

[0035] Figure 15 It is the seventh schematic diagram of the results of the power control method for the power system provided by the embodiment of the present application;

[0036] Figure 16 It is the eighth schematic diagram of the results of the power control method for the power system provided by the embodiment of the present application;

[0037] Figure 17 It is the ninth schematic diagram of the results of the power control method for the power system provided by the embodiment of the present application;

[0038] Figure 18 It is the tenth schematic diagram of the results of the power control method for the power system provided by the embodiment of the present application;

[0039] Figure 19 It is the eleventh schematic diagram of the results of the power control method for the power system provided by the embodiment of the present application;

[0040] Figure 20 It is the twelfth schematic diagram of the results of the power control method for the power system provided by the embodiment of the present application;

[0041] Figure 21 It is the thirteenth schematic diagram of the results of the power control method for the power system provided by the embodiment of the present application;

[0042] Figure 22 It is the schematic diagram of the structure of the power control device for the power system provided by the embodiment of the present application;

[0043] Figure 23 It is the schematic diagram of the structure of the electronic device provided by the embodiment of the present application. Detailed implementation manners

[0044] Next, the technical solutions in the embodiments of the present application will be clearly described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0045] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are usually of the same type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally indicates an "or" relationship between the associated objects before and after.

[0046] Next, in conjunction with the accompanying drawings, the power control method of the power system, the power control device of the power system, the electronic device, and the readable storage medium provided by the embodiments of the present application will be described in detail through specific embodiments and their application scenarios.

[0047] Among them, the power control method of the power system can be applied to a terminal, and specifically can be executed by hardware or software in the terminal.

[0048] In the following various embodiments, a terminal including a display and a touch-sensitive surface is described. However, it should be understood that the terminal may include one or more other physical user interface devices such as a physical keyboard, a mouse, and a joystick.

[0049] The power control method of the power system provided by the embodiments of the present application, the execution subject of the power control method of the power system can be an electronic device or a functional module or functional entity in the electronic device that can implement the power control method of the power system. The electronic devices mentioned in the embodiments of the present application include, but are not limited to, mobile phones, tablet computers, computers, cameras, and wearable devices, etc. Here, taking the electronic device as the execution subject as an example, the power control method of the power system provided by the embodiments of the present application will be described.

[0050] As Figure 1 shown, the power control method of the power system includes: step 110, step 120, and step 130.

[0051] The power control method of the power system can be applied to an off-grid operation scenario.

[0052] Step 110: Obtain the expected value of the DC-side power response corresponding to the target power conversion device in at least one power conversion device;

[0053] In this step, the power system includes at least one power conversion device, and each power conversion device is respectively connected to an AC coupling point, such as Figure 2 shown at point A in

[0054] Each power conversion device includes a first converter and at least one DC module. The first converter is connected to the DC module, and the power conversion device is used to connect to an external device via the AC coupling point.

[0055] Among them, the external device can be an electrical device, such as an electrical load; or it can also be a third-party power generation device, such as a third-party inverter or a power generation load, etc.

[0056] Such as Figure 4 shown, in the same power conversion device, each DC module is respectively connected to the first converter via a DC coupling point B.

[0057] In some embodiments, the DC module can include a DC converter and a power generation device, an electrical device or an energy storage device connected to the DC converter. Among them, the power generation device such as a photovoltaic device, a wind power generation device or other new energy power generation devices, etc.; the electrical device such as a charging pile, etc., and the energy storage device such as an energy storage battery, etc.

[0058] Depending on the type of device connected to the DC converter, the DC module also corresponds to multiple categories. The categories of the DC module can be: a power generation device, an electrical device or an energy storage device, etc.

[0059] Depending on the type of the DC module included in the power conversion device, its own type may also be different. It can be understood that the power conversion device can be categories such as a pure energy storage module, a pure photovoltaic module, a photovoltaic and energy storage module, a photovoltaic, energy storage and charging module or other combined modules, etc., which can be specifically set according to actual needs and are not limited herein; for example, when the power conversion device includes a first converter and one or more photovoltaic devices, the power conversion device is a pure photovoltaic module; when the power conversion device includes a first converter and one or more energy storage devices, the power conversion device is a pure energy storage module; when the power conversion device includes a first converter, a photovoltaic device and an energy storage device, the power conversion device can be a photovoltaic and energy storage module.

[0060] The target power conversion device can be any device among all the power conversion devices included in the power system.

[0061] The expected value of the DC-side power response corresponding to the target power conversion device is the expected response power corresponding to the target power conversion device at the DC coupling point. Hereinafter, Px_dc represents the expected value of the DC-side power response of the x-th power conversion device, where x is a positive integer. It can be understood that the expected values of the DC-side power responses corresponding to different power conversion devices may be the same or different; the expected values of the DC-side power responses of the same power conversion device at different times may also be different.

[0062] The expected value of the DC-side power response corresponding to the target power conversion device can be expressed as the sum of the expected values of the sub-DC-side power responses corresponding to each DC module included in the target power conversion device.

[0063] In some embodiments, step 110 may include:

[0064] Determine the expected value of the sub-DC-side power response corresponding to each DC module according to the category of each DC module included in the target power conversion device;

[0065] Based on the sum of the expected values of the sub-DC-side power responses corresponding to each DC module, determine the expected value of the DC-side power response corresponding to the target power conversion device.

[0066] In this embodiment, the categories of DC modules may include: energy storage devices, power generation devices, and electrical equipment, etc.

[0067] A power conversion device may include one DC module or multiple DC modules. The multiple DC modules included may be DC modules of the same category, such as pure energy storage modules or pure power generation devices, etc.; the multiple DC modules included may also be DC modules of different categories, such as energy storage + power generation devices, energy storage + electrical equipment, power generation + electrical equipment, and energy storage + power generation + electrical equipment, etc.

[0068] When calculating the expected value of the DC-side power response corresponding to the target power conversion device, the expected value of the sub-DC-side power response corresponding to each DC module included therein should be calculated first, and then the expected values of the sub-DC-side power responses are summed. It should be noted that the expected value of the sub-DC-side power response and the expected value of the DC-side power response, etc. are all vectors, including magnitude and direction. Among them, the discharge direction is positive and the charge direction is negative.

[0069] For DC modules of different categories, the methods for determining the corresponding expected values of the sub-DC-side power responses are different.

[0070] In some embodiments, the expected value of the sub-DC-side power response corresponding to a DC module can be determined according to at least one of the category of the DC module, the performance parameters of the DC module, the power scheduling of the DC module, and the charging request power corresponding to the DC module.

[0071] In this embodiment, the categories of each DC module can be determined first, and then the corresponding calculation method can be selected according to the category. In some embodiments, when calculating the expected value of the sub-DC side power response, the first AC side scheduling parameter value also needs to be comprehensively considered. The first AC side scheduling parameter value is determined according to the actual electrical signal at the AC coupling point and the first electrical signal reference value. The specific determination method will be described in the following embodiments and will not be elaborated here for the time being.

[0072] In some embodiments, determining the expected value of the sub-DC side power response corresponding to each DC module according to the categories of the DC modules included in the target power conversion device may include:

[0073] When the DC module is a power generation device, the maximum power generation of the power generation device is determined as the expected value of the sub-DC side power response corresponding to the power generation device;

[0074] When the DC module is an electrical equipment, the charging request power corresponding to the electrical equipment is determined as the expected value of the sub-DC side power response corresponding to the electrical equipment;

[0075] When the DC module is an energy storage device, the expected value of the sub-DC side power response corresponding to the energy storage device is determined according to the categories of other DC modules connected to the energy storage device and the first AC side scheduling parameter value.

[0076] In this embodiment, when the DC module is a power generation device, the expected value of the sub-DC side power response is the maximum power expected to be output, that is, the maximum power generation, and the maximum power generation is a positive value; taking a photovoltaic module as an example, it can be the maximum photovoltaic power expected to be output.

[0077] When the DC module is an electrical equipment, such as a charging pile, the expected value of the sub-DC side power response can be the charging request power of the electrical equipment connected to the charging pile, and the charging request power is a negative value.

[0078] When the DC module is an energy storage device, the expected value of the sub-DC side power response can be the energy storage scheduling power expected to respond within the allowable range of performance parameters and under the condition of balanced distribution, and can be specifically determined according to the categories of other DC modules connected to the energy storage device and the first AC side scheduling parameter value.

[0079] In some embodiments, when the DC module is an energy storage device, determining the expected value of the sub-DC side power response corresponding to the energy storage device according to the categories of other DC modules connected to the energy storage device and the first AC side scheduling parameter value may include:

[0080] When all other DC modules connected to the energy storage device are energy storage devices, or when there are no other devices connected to the energy storage device, determine the expected value of the sub-DC side power response corresponding to the energy storage device according to the absolute value of the maximum charge-discharge power corresponding to the energy storage device, the absolute value of the first AC side scheduling parameter value, and the charge-discharge state corresponding to the maximum charge-discharge power;

[0081] When at least one of a power generation device and an electrical device is included in other DC modules connected to the energy storage device, determine the energy storage scheduling power corresponding to the energy storage device according to the first AC side scheduling parameter value and the expected value of the sub-DC side power response corresponding to each target module;

[0082] Based on the energy storage scheduling power corresponding to the energy storage device, the charge-discharge state corresponding to the energy storage scheduling power, and the maximum charge-discharge power corresponding to the energy storage device, determine the expected value of the sub-DC side power response corresponding to the energy storage device.

[0083] In this embodiment, the target module is a power generation device and / or an electrical device connected to the energy storage device. The expected value of the sub-DC side power response corresponding to the power generation device is the maximum power generation, and the expected value of the sub-DC side power response corresponding to the electrical device is the charging request power.

[0084] For the case where the target power conversion device is a pure energy storage device, the expected value of the sub-DC side power response corresponding to the energy storage device can be determined according to the absolute value of the maximum charge-discharge power corresponding to the energy storage device, the absolute value of the first AC side scheduling parameter value, and the charge-discharge state corresponding to the maximum charge-discharge power.

[0085] If the absolute value of the maximum charge-discharge power is less than the absolute value of the first AC side scheduling parameter value, the expected value of the sub-DC side power response should be determined as the maximum charge-discharge power; if the absolute value of the maximum charge-discharge power is greater than the absolute value of the first AC side scheduling parameter value, the expected value of the sub-DC side power response should be determined as the first AC side scheduling parameter value.

[0086] For the case where the target power device is a hybrid module of an energy storage device and other types of devices, it should be comprehensively determined in combination with the first AC side scheduling parameter value.

[0087] It can be understood that for a hybrid module containing an energy storage device, the energy storage scheduling power = the first AC side scheduling parameter value + the expected value of the sub-DC side power response corresponding to each target module; among them, the expected value of the sub-DC side power response corresponding to each target module may be positive or negative.

[0088] After obtaining the energy storage dispatching power, the expected value of the sub-DC-side power response corresponding to the energy storage device is determined by combining the magnitude relationship between the absolute value of the energy storage dispatching power and the absolute value of the maximum charge-discharge power. If the absolute value of the maximum charge-discharge power is less than the absolute value of the energy storage dispatching power, the expected value of the sub-DC-side power response should be determined as the maximum charge-discharge power; if the absolute value of the maximum charge-discharge power is greater than the absolute value of the energy storage dispatching power, the expected value of the sub-DC-side power response should be determined as the energy storage dispatching power.

[0089] Among them, the maximum charge-discharge power includes: the maximum charging power and the maximum discharging power. The maximum charging power is negative, and the maximum discharging power is positive.

[0090] The maximum discharging power of the energy storage device represents the maximum discharging power comprehensively obtained based on the current energy storage device within the allowable range of performance parameters and under the condition of balanced distribution; the maximum charging power of the energy storage device represents the maximum charging power comprehensively obtained based on the current energy storage device within the allowable range of performance parameters and under the condition of balanced distribution.

[0091] After obtaining the expected value of the sub-DC-side power response corresponding to the energy storage device, the expected value of the sub-DC-side power response corresponding to the energy storage device is summed with the expected values of the sub-DC-side power responses corresponding to other target modules, and the expected value of the DC-side power response corresponding to the target power conversion device can be obtained.

[0092] The following describes the specific determination method of the expected value of the DC-side power response at the DC coupling point of a certain power conversion device.

[0093] 1. If the power conversion device is a pure energy storage device:

[0094] The expected value of the DC-side power response at the DC coupling point is the ability of the energy storage device to currently respond to the first AC-side dispatching parameter value.

[0095] 1) When the first AC-side dispatching parameter value is in the discharging direction:

[0096] When the absolute value of the maximum discharging power of the energy storage device < the absolute value of the first AC-side dispatching parameter value, the expected value of the DC-side power response at the DC coupling point = the maximum discharging power;

[0097] When the absolute value of the maximum discharging power of the energy storage device > the absolute value of the first AC-side dispatching parameter value, the expected value of the DC-side power response at the DC coupling point = the first AC-side dispatching parameter value;

[0098] 2) When the first AC-side dispatching parameter value is in the charging direction:

[0099] When the absolute value of the maximum charging power of the energy storage device < the absolute value of the first AC-side dispatching parameter value, the expected value of the DC-side power response at the DC coupling point = the maximum charging power;

[0100] When the absolute value of the maximum charging power of the energy storage device > the absolute value of the first AC-side scheduling parameter value, the expected value of the DC-side power response at the DC coupling point = the first AC-side scheduling parameter value.

[0101] 2. If the power conversion device is a pure optical device:

[0102] The expected value of the DC-side power response at the DC coupling point is the maximum output power of the power generation device in the current state.

[0103] 3. If the power conversion device is an optical storage device:

[0104] The expected value of the DC-side power response at the DC coupling point is the maximum available output power of the current power generation device.

[0105] The expected value of the sub-DC-side power response corresponding to the power generation device is: the maximum power generation;

[0106] The energy storage scheduling power = the first AC-side scheduling parameter value - the absolute value of the maximum power generation;

[0107] 1) When the energy storage scheduling power is in the discharging direction:

[0108] a. When the absolute value of the maximum discharging power of the energy storage device < the absolute value of the energy storage scheduling power,

[0109] The expected value of the sub-DC-side power response corresponding to the energy storage device = the maximum discharging power;

[0110] The expected value of the DC-side power response = the expected value of the sub-DC-side power response corresponding to the power generation device + the expected value of the sub-DC-side power response corresponding to the energy storage device = the absolute value of the maximum power generation + the absolute value of the maximum discharging power of the energy storage device;

[0111] b. When the absolute value of the maximum discharging power of the energy storage device > the absolute value of the energy storage scheduling power,

[0112] The expected value of the sub-DC-side power response corresponding to the energy storage device = the energy storage scheduling power;

[0113] The expected value of the DC-side power response = the expected value of the sub-DC-side power response corresponding to the power generation device + the expected value of the sub-DC-side power response corresponding to the energy storage device = the absolute value of the maximum power generation + the first AC-side scheduling parameter value - the absolute value of the maximum power generation = the first AC-side scheduling parameter value;

[0114] 2) When the energy storage scheduling power is in the charging direction:

[0115] a. When the absolute value of the maximum charging power of the energy storage device < the absolute value of the energy storage scheduling power,

[0116] The expected value of the sub-DC-side power response corresponding to the energy storage device = the maximum charging power;

[0117] The expected value of the DC-side power response = the expected value of the sub-DC-side power response corresponding to the power generation device + the expected value of the sub-DC-side power response corresponding to the energy storage device = the absolute value of the maximum power generation - the absolute value of the maximum charging power of the energy storage device;

[0118] b. When the absolute value of the maximum charging power of the energy storage device > the absolute value of the energy storage scheduling power,

[0119] The expected value of the sub-DC-side power response corresponding to the energy storage device = the energy storage scheduling power;

[0120] The expected value of the DC-side power response = the expected value of the sub-DC-side power response corresponding to the power generation device + the expected value of the sub-DC-side power response corresponding to the energy storage device = the absolute value of the maximum power generation + the first AC-side scheduling parameter value - the absolute value of the maximum power generation = the first AC-side scheduling parameter value.

[0121] 4. If the power conversion device is a pure energy storage device + an electrical equipment:

[0122] The expected value of the DC-side power response at the DC coupling point is the current response of the energy storage device to the first AC-side scheduling parameter value and the capacity of the electrical equipment.

[0123] The expected value of the sub-DC-side power response corresponding to the electrical equipment is: the charging request power;

[0124] The energy storage scheduling power = the first AC-side scheduling parameter value + the absolute value of the charging request power;

[0125] 1) When the energy storage scheduling power is in the discharging direction:

[0126] a. When the absolute value of the maximum discharging power of the energy storage device < the absolute value of the energy storage scheduling power,

[0127] The expected value of the sub-DC-side power response corresponding to the energy storage device = the maximum discharging power;

[0128] The expected value of the DC-side power response = the expected value of the sub-DC-side power response corresponding to the electrical equipment + the expected value of the sub-DC-side power response corresponding to the energy storage device = - the absolute value of the charging request power + the absolute value of the maximum discharging power of the energy storage device;

[0129] b. When the absolute value of the maximum discharging power of the energy storage device > the absolute value of the energy storage scheduling power,

[0130] The expected value of the sub-DC-side power response corresponding to the energy storage device = the energy storage scheduling power;

[0131] DC-side power response expected value = Sub-DC-side power response expected value corresponding to the electrical equipment + Sub-DC-side power response expected value corresponding to the energy storage equipment = - Absolute value of the charging request power + First AC-side scheduling parameter value + Absolute value of the charging request power = First AC-side scheduling parameter value;

[0132] 2) When the energy storage scheduling power is in the charging direction:

[0133] a. When the absolute value of the maximum charging power of the energy storage equipment < Absolute value of the energy storage scheduling power,

[0134] Sub-DC-side power response expected value corresponding to the energy storage equipment = Maximum charging power;

[0135] DC-side power response expected value = Sub-DC-side power response expected value corresponding to the electrical equipment + Sub-DC-side power response expected value corresponding to the energy storage equipment = - Absolute value of the charging request power - Absolute value of the maximum charging power of the energy storage equipment;

[0136] b. When the absolute value of the maximum charging power of the energy storage equipment > Absolute value of the energy storage scheduling power,

[0137] Sub-DC-side power response expected value corresponding to the energy storage equipment = Energy storage scheduling power;

[0138] DC-side power response expected value = Sub-DC-side power response expected value corresponding to the electrical equipment + Sub-DC-side power response expected value corresponding to the energy storage equipment = - Absolute value of the charging request power + First AC-side scheduling parameter value + Absolute value of the charging request power = First AC-side scheduling parameter value.

[0139] 5. If the power conversion equipment is a photovoltaic energy storage equipment + electrical equipment:

[0140] The DC-side power response expected value of the DC coupling point is: The maximum output power of the power generation equipment in the current state and the energy storage equipment together respond to the first AC-side scheduling parameter value and the charging ability of the electrical equipment.

[0141] Sub-DC-side power response expected value corresponding to the power generation equipment is: Maximum power generation;

[0142] Sub-DC-side power response expected value corresponding to the electrical equipment is: Charging request power;

[0143] Energy storage scheduling power is: First AC-side scheduling parameter value + Absolute value of the charging request power - Absolute value of the maximum power generation;

[0144] 1) When the energy storage scheduling power is in the discharging direction:

[0145] a. When the absolute value of the maximum discharging power of the energy storage equipment < Absolute value of the energy storage scheduling power,

[0146] The expected value of the sub - DC - side power response corresponding to the energy storage device = the maximum discharge power;

[0147] The expected value of the DC - side power response = the expected value of the sub - DC - side power response corresponding to the power generation device+the expected value of the sub - DC - side power response corresponding to the power consumption device+the expected value of the sub - DC - side power response corresponding to the energy storage device = the absolute value of the maximum power generation−the absolute value of the charging request power+the absolute value of the maximum discharge power of the energy storage device;

[0148] b. When the absolute value of the maximum discharge power of the energy storage device>the absolute value of the energy storage scheduling power,

[0149] The expected value of the sub - DC - side power response corresponding to the energy storage device = the energy storage scheduling power;

[0150] The expected value of the DC - side power response = the expected value of the sub - DC - side power response corresponding to the power generation device+the expected value of the sub - DC - side power response corresponding to the power consumption device+the expected value of the sub - DC - side power response corresponding to the energy storage device = the absolute value of the maximum power generation−the absolute value of the charging request power+the first AC - side scheduling parameter value+the absolute value of the charging request power−the absolute value of the maximum power generation = the first AC - side scheduling parameter value;

[0151] 2) When the energy storage scheduling power is in the charging direction:

[0152] a. When the maximum charging power of the energy storage device<the energy storage scheduling power,

[0153] The expected value of the sub - DC - side power response corresponding to the energy storage device = the maximum charging power;

[0154] The expected value of the DC - side power response = the expected value of the sub - DC - side power response corresponding to the power generation device+the expected value of the sub - DC - side power response corresponding to the power consumption device+the expected value of the sub - DC - side power response corresponding to the energy storage device = the absolute value of the maximum power generation−the absolute value of the charging request power−the absolute value of the maximum charging power of the energy storage device;

[0155] b. When the maximum charging power of the energy storage device>the energy storage scheduling power,

[0156] The expected value of the sub - DC - side power response corresponding to the energy storage device = the energy storage scheduling power;

[0157] The expected value of the DC - side power response = the expected value of the sub - DC - side power response corresponding to the power generation device+the expected value of the sub - DC - side power response corresponding to the power consumption device+the expected value of the sub - DC - side power response corresponding to the energy storage device = the absolute value of the maximum power generation−the absolute value of the charging request power+the first AC - side scheduling parameter value+the absolute value of the charging request power−the absolute value of the maximum power generation = the first AC - side scheduling parameter value;

[0158] 6. If the power conversion device is a power generation device + an electrical equipment:

[0159] The expected value of the DC-side power response at the DC coupling point is: the maximum available output power response of the power generation device at the current state and the first AC-side scheduling parameter value, and the charging capacity of the electrical equipment.

[0160] The expected value of the sub-DC-side power response corresponding to the power generation device is: the maximum power generation;

[0161] The expected value of the sub-DC-side power response corresponding to the electrical equipment is: the charging request power;

[0162] The expected value of the DC-side power response = the expected value of the sub-DC-side power response corresponding to the power generation device + the expected value of the sub-DC-side power response corresponding to the electrical equipment = the absolute value of the maximum power generation - the absolute value of the charging request power.

[0163] It can be understood that for each power conversion device, the expected value of the DC-side power response at the corresponding DC coupling point is comprehensively determined according to the expected value of the sub-DC-side power response of each DC module and the first AC-side scheduling parameter value in the current working state of the power conversion device. In the actual execution process, it can be calculated by the first converter corresponding to the power conversion device.

[0164] Step 120: Determine the target AC electrical signal corresponding to the target power conversion device according to the expected value of the DC-side power response corresponding to the target power conversion device, the actual electrical signal at the AC coupling point, and the first electrical signal reference value at the AC coupling point;

[0165] In this step, the first electrical signal reference value is used to represent the rated voltage or a voltage range within a certain range above and below the rated voltage (such as ±10% or ±20%), which represents the voltage range in which external devices (such as loads) connected to the power system can work normally. It can be specifically defined by the user or set correspondingly according to the connected external devices, and this application does not make any limitations.

[0166] In some embodiments, the first electrical signal reference value can be determined based on the rated voltage of the power grid in the area where the power system is located, and is used to enable the load connected to the power system to operate normally.

[0167] For example, when the rated voltage of the power grid is 220V, the first electrical signal reference value can be set to 220V or 220V ± 2V, etc.

[0168] The actual electrical signal can include the amplitude, effective value, or frequency of the actual voltage at the AC coupling point, etc.

[0169] When the actual electrical signal is the amplitude or effective value of the voltage, the first electrical signal reference value, the second electrical signal reference value, and the second electrical signal reference value of the AC coupling point can be set to the reference values corresponding to the amplitude or effective value of the voltage. When the actual electrical signal is the frequency of the voltage, the first electrical signal reference value, the second electrical signal reference value, and the second electrical signal reference value of the AC coupling point can be set to the reference values corresponding to the frequency of the voltage.

[0170] The actual electrical signal is the amplitude, effective value, frequency, etc. of the voltage, and their corresponding control logics are similar. Below, the amplitude of the voltage is taken as an example for illustration.

[0171] For convenience of description, hereinafter, Upcc represents the actual electrical signal of the AC coupling point, U1_ref represents the first electrical signal reference value of the AC coupling point, Px_dc represents the expected value of the DC-side power response of the xth power conversion device, and Px_ac_1 represents the first AC-side scheduling parameter value of the xth power conversion device.

[0172] In some embodiments, step 120 may include:

[0173] Determine the first AC-side scheduling parameter value according to the actual electrical signal of the AC coupling point and the first electrical signal reference value;

[0174] Determine the target AC electrical signal corresponding to the target power conversion device according to the first AC-side scheduling parameter value and the expected value of the DC-side power response of the target power conversion device.

[0175] In this embodiment, as Figure 5 shown, by taking the difference between the first electrical signal reference value and the actual electrical signal of the AC coupling point and performing PI control according to the difference, the first AC-side scheduling parameter value for making the actual electrical signal of the AC coupling point follow the first electrical signal reference value can be obtained.

[0176] It can be understood that for a single-machine system, the first AC-side scheduling parameter value corresponding to this AC coupling point is the first AC-side scheduling parameter value corresponding to this power conversion device; for a multi-machine parallel system, each power conversion device can still be regarded as an independent individual. According to the actual electrical signal of the AC coupling point and the first electrical signal reference value, determine the first control signal; according to the first control signal and the first converter parameter corresponding to the target power conversion device, determine the first AC-side scheduling parameter value corresponding to the target power conversion device.

[0177] Then, according to the magnitude relationship between the first AC-side scheduling parameter value corresponding to the target power conversion device and the expected value of the DC-side power response of the target power conversion device, determine the target AC electrical signal.

[0178] In some embodiments, determining a target alternating current signal corresponding to a target power conversion device according to a first alternating current side scheduling parameter value and an expected value of a direct current side power response corresponding to the target power conversion device may include:

[0179] When the absolute value of the difference between the first alternating current side scheduling parameter value and the expected value of the direct current side power response is less than a first threshold, determining the target alternating current signal as the first alternating current side scheduling parameter value;

[0180] When the absolute value of the difference between the first alternating current side scheduling parameter value and the expected value of the direct current side power response is not less than the first threshold, determining the target alternating current signal as the expected value of the direct current side power response.

[0181] In this embodiment, the absolute value of the difference between the first alternating current side scheduling parameter value and the expected value of the direct current side power response may be expressed as the absolute value of a difference or a ratio. The first threshold is a relatively small value, such as 0 or a positive number approaching 0, etc.

[0182] When the absolute value of the difference between the first alternating current side scheduling parameter value and the expected value of the direct current side power response is less than the first threshold, it can be approximately considered that the first alternating current side scheduling parameter value is equal to the expected value of the direct current side power response; when the absolute value of the difference between the first alternating current side scheduling parameter value and the expected value of the direct current side power response is not less than the first threshold, it is considered that the first alternating current side scheduling parameter value is not equal to the expected value of the direct current side power response.

[0183] When the first alternating current side scheduling parameter value is approximately equal to the expected value of the direct current side power response, the target power conversion device may be controlled to continue operating according to the first alternating current side scheduling parameter value.

[0184] When the first alternating current side scheduling parameter value is not equal to the expected value of the direct current side power response, the target power conversion device should be controlled to operate according to the expected value of the direct current side power response.

[0185] The specific determination method of the expected value of the direct current side power response has been described in the above embodiments and will not be elaborated here.

[0186] In this application, for each power conversion device in a single - machine scenario or a parallel - machine scenario, independent control can be performed according to the above - mentioned control method; in a parallel - machine scenario, each power conversion device operates according to the target alternating current signal determined by itself, so as to achieve overall balanced control.

[0187] According to the power control method of the power system provided by the embodiments of the present application, by the magnitude of the expected value of the DC-side power response corresponding to the target power conversion device and the first AC-side scheduling parameter value of the AC coupling point, the target AC power signal for adjusting the first converter of the power conversion device is determined to control the first converter, so as to adjust the power supply relationship between the power conversion devices, and make the power conversion devices reach a balanced state.

[0188] Step 130: Based on the target AC power signal, control the operating state of the target power conversion device to adjust the power supply relationship between the power conversion devices.

[0189] In this step, the operating state includes the charge-discharge state and the charge-discharge power, etc., and the charge-discharge state includes the charge state or the discharge state.

[0190] It should be noted that for each power conversion device, the target AC power signal corresponding to it can be calculated in the manner of steps 110 to 120, and then the power conversion device can be independently controlled according to the target AC power signal.

[0191] According to the power control method of the power system provided by the embodiments of the present application, by the expected value of the DC-side power response corresponding to the target power conversion device and the first electrical signal reference value of the AC coupling point, the target AC power signal for adjusting the first converter of the power conversion device is determined to control the first converter, so as to adjust the power supply relationship between the power conversion devices, and make the power conversion devices reach a balanced state.

[0192] In some embodiments, determining the first AC-side scheduling parameter value according to the actual electrical signal of the AC coupling point and the first electrical signal reference value may include:

[0193] Determine the first control signal according to the actual electrical signal of the AC coupling point and the first electrical signal reference value;

[0194] According to the first converter parameters corresponding to the target power conversion device, convert the first control signal into the first AC-side scheduling parameter value for adjusting the first converter.

[0195] In this embodiment, the first converter parameters may include: parameters such as the parallel rated capacity, local device rated capacity, local device rated current, local device maximum current, local device rated voltage, and local device maximum voltage corresponding to the target power conversion device.

[0196] The first control signal can be expressed as different parameter categories such as power, voltage, and current. In the actual execution process, according to the different parameter categories of the first control signal, the corresponding conversion formula can be selected for conversion to obtain the first AC-side scheduling parameter value.

[0197] For example, when the first control signal is power, the conversion can be performed through the following conversion formula:

[0198] The first AC-side scheduling parameter value = the first control signal ÷ the sum of the parallel machine rated capacities * the rated capacity of the local device.

[0199] Also, for example, when the first control signal is voltage, the conversion can be performed through the following conversion formula:

[0200] The first AC-side scheduling parameter value = the first control signal ÷ the sum of the parallel machine rated capacities * the rated capacity of the local device * K1;

[0201] Wherein, K1 represents the coefficient for converting voltage to power, including but not limited to the rated current of the local device, the maximum current of the local device, etc.

[0202] Still, for example, when the first control signal is current, the conversion can be performed through the following conversion formula:

[0203] The first AC-side scheduling parameter value = the first control signal ÷ the sum of the parallel machine rated capacities * the rated capacity of the local device * K2;

[0204] Wherein, K2 represents the coefficient for converting current to power, including but not limited to the rated voltage of the local device, the maximum voltage of the local device, etc.

[0205] In some embodiments, determining the first control signal according to the actual electrical signal at the AC coupling point and the first electrical signal reference value may include:

[0206] Generating the first control signal according to the first difference between the actual electrical signal and the first electrical signal reference value.

[0207] In this embodiment, the first control signal can be obtained by controlling using the PI control algorithm based on the difference between the actual electrical signal at the AC coupling point and the first electrical signal reference value, so that the actual electrical signal at the AC coupling point can track the first electrical signal reference value.

[0208] Of course, in other embodiments, other control algorithms can also be used to determine the first control signal according to the actual electrical signal at the AC coupling point and the first electrical signal reference value, which is not limited herein.

[0209] In some embodiments, determining the target AC electrical signal corresponding to the target power conversion device according to the first AC-side scheduling parameter value and the expected DC-side power response value corresponding to the target power conversion device may include:

[0210] Determining the target AC electrical signal based on the first AC-side scheduling parameter value and the expected DC-side power response value;

[0211] Limit the upper and / or lower threshold of the target AC signal to correct the target AC signal.

[0212] In this embodiment, the specific determination method of the target AC signal based on the first AC-side scheduling parameter value and the DC-side power response expectation value has been described in the above embodiments and will not be elaborated here.

[0213] In some embodiments, the determined target AC signal can also be threshold-limited according to the upper and lower thresholds to further maintain the normal operation of the power system.

[0214] The upper and lower thresholds can be user-defined or adaptively adjusted according to the actual application scenario. In some embodiments, the upper and lower thresholds may include at least one of a second electrical signal reference value and a third electrical signal reference value.

[0215] Wherein, the second electrical signal reference value is greater than the first electrical signal reference value, and the first electrical signal reference value is greater than the third electrical signal reference value.

[0216] In some embodiments, the second electrical signal reference value can be the maximum power value for the system to operate normally; the third electrical signal reference value can be the minimum power value for the system to operate normally.

[0217] In some embodiments, the second electrical signal reference value can be determined based on the sampling error of the first converter and / or the maximum electrical signal of external devices connected to the power system under normal operating conditions.

[0218] In this embodiment, the external device can be an electrical equipment or a power generation equipment.

[0219] The second electrical signal reference value can be the maximum electrical signal of external devices connected to the power system under normal operating conditions, or a value near the maximum electrical signal of external devices connected to the power system under normal operating conditions.

[0220] Alternatively, the second electrical signal reference value can be determined based on the sampling error of the first converter, so that the absolute value of the difference between the second electrical signal reference value and the first electrical signal reference value can at least cover the sampling error of the first converter regarding the AC voltage.

[0221] It should be noted that regardless of how the second electrical signal reference value is determined, it is necessary to ensure that the first electrical signal reference value is less than the second electrical signal reference value.

[0222] In some embodiments, the third electrical signal reference value is determined based on the sampling error of the first converter and / or the minimum electrical signal of external devices connected to the power system under normal operating conditions.

[0223] In this embodiment, the external device can be an electrical equipment or a power generation equipment.

[0224] The reference value of the third electrical signal may be the minimum electrical signal of an external device connected to the power system under normal operating conditions, or a value near the minimum electrical signal of the external device connected to the power system under normal operating conditions.

[0225] Alternatively, the reference value of the third electrical signal may be determined based on the sampling error of the first converter, so that the absolute value of the difference between the reference value of the third electrical signal and the reference value of the first electrical signal can at least cover the sampling error of the first converter with respect to the AC voltage.

[0226] It should be noted that regardless of how the reference value of the third electrical signal is determined, the reference value of the first electrical signal must be greater than the reference value of the third electrical signal.

[0227] In some embodiments, the reference values of the first electrical signal, the second electrical signal, and the third electrical signal may be dynamically changing values.

[0228] In some embodiments, at least one of the reference values of the first electrical signal, the second electrical signal, and the third electrical signal may be set correspondingly according to the operating time period of the power system and / or the category of the external device connected to the power system.

[0229] In this embodiment, the external device may be an electrical equipment or a power generation equipment, such as an electrical load or a third-party inverter, etc.

[0230] In the actual execution process, it may be different fixed values within the different time periods set by the user of this power system; or, it may also set the reference value of the first electrical signal adapted to it correspondingly according to the change of the external device type, and the reference values of the second electrical signal and the third electrical signal linked to it.

[0231] It should be noted that regardless of how the reference values of each electrical signal change, it is necessary to ensure that the relationship that the reference value of the second electrical signal is greater than the reference value of the first electrical signal and the reference value of the first electrical signal is greater than the reference value of the third electrical signal is satisfied.

[0232] In some embodiments, limiting the upper and / or lower threshold values of the target AC electrical signal and correcting the target AC electrical signal may include:

[0233] When the target AC electrical signal is greater than the second AC electrical signal, update the target AC electrical signal to the second AC electrical signal.

[0234] In this embodiment, the second AC electrical signal is determined based on the actual electrical signal and the reference value of the second electrical signal at the AC coupling point, and the reference value of the second electrical signal is greater than the reference value of the first electrical signal.

[0235] In some embodiments, the second alternating current signal is determined based on the actual electrical signal and the second electrical signal reference value of the AC coupling point, and may include:

[0236] Determine the second alternating current signal according to the actual electrical signal of the AC coupling point and the second electrical signal reference value.

[0237] In some embodiments, determining the second alternating current signal according to the actual electrical signal of the AC coupling point and the second electrical signal reference value may include:

[0238] Determine the second control signal according to the actual electrical signal of the AC coupling point and the second electrical signal reference value;

[0239] Convert the second control signal into a second alternating current signal for adjusting the first converter according to the first converter parameter corresponding to the target power conversion device.

[0240] In this embodiment, as Figure 5 shown, the second control signal can be obtained by PI control according to the difference between the actual electrical signal of the AC coupling point and the second electrical signal reference value U2_REF; then, in combination with the first converter parameter corresponding to the target power conversion device, the second control signal is converted into a second alternating current signal for adjusting the first converter. As Figure 6 shown, if the category corresponding to the second control signal is power, voltage or current, select the corresponding conversion method to convert it into a second alternating current signal. The specific conversion formula is similar to the conversion method of the first control signal, and details are not described herein.

[0241] As Figure 7 shown, when the target alternating current signal is greater than the second alternating current signal, it is considered that the target alternating current signal exceeds the maximum threshold at which the system can operate normally. Then, update the target alternating current signal to the second alternating current signal, so that the target power conversion device operates according to the second alternating current signal, that is, operates with the maximum output capacity under normal working conditions.

[0242] In some embodiments, limiting the upper and / or lower threshold of the target alternating current signal and correcting the target alternating current signal may include:

[0243] When the target alternating current signal is less than the third alternating current signal, update the target alternating current signal to the third alternating current signal.

[0244] In this embodiment, the third alternating current signal is determined based on the actual electrical signal and the third electrical signal reference value of the AC coupling point, and the third electrical signal reference value is less than the first electrical signal reference value.

[0245] In some embodiments, the third alternating current signal is determined based on the actual electrical signal and the third electrical signal reference value of the AC coupling point, and may include:

[0246] Determine the third alternating current signal according to the actual electrical signal of the AC coupling point and the third electrical signal reference value.

[0247] In some embodiments, determining the third alternating current signal according to the actual electrical signal of the AC coupling point and the third electrical signal reference value may include:

[0248] Determine the third control signal according to the actual electrical signal of the AC coupling point and the third electrical signal reference value;

[0249] Convert the third control signal into a third alternating current signal for adjusting the first converter according to the first converter parameter corresponding to the target power conversion device.

[0250] In this embodiment, as Figure 5 shown, the third control signal can be obtained by PI control according to the difference between the actual electrical signal of the AC coupling point and the second electrical signal reference value; then, in combination with the first converter parameter corresponding to the target power conversion device, the third control signal is converted into a third alternating current signal for adjusting the first converter, as Figure 6 shown. For example, according to the category of the third control signal being power, voltage or current, select the corresponding conversion method to convert it into the third alternating current signal. The specific conversion formula is similar to the conversion method of the first control signal, and the present application will not elaborate here.

[0251] As Figure 7 shown, when the target alternating current signal is less than the third alternating current signal, it is considered that the target alternating current signal is lower than the minimum threshold at which the system can operate normally. Then, update the target alternating current signal to the third alternating current signal, so that the target power conversion device operates according to the third alternating current signal, that is, operates with the minimum output capacity under normal working conditions.

[0252] According to the power control method of the power system provided by the embodiments of the present application, by limiting the upper and / or lower threshold values of the target alternating current signal, it is possible to ensure the balanced operation of each power conversion device while ensuring that the operating parameters of each power conversion device are maintained within the normal range, reduce the impact and damage to the equipment, and improve the operating stability.

[0253] In some embodiments, step 130 may include:

[0254] Perform closed-loop control on the target power conversion device based on the target alternating current signal and the actual electrical signal of the controlled point corresponding to the AC coupling point.

[0255] In this embodiment, PI control can be performed on the target power conversion device according to the difference between the target AC signal and the actual electrical signal.

[0256] In some embodiments, the controlled point can be an AC coupling point; or the controlled point can also be, as Figure 8 shown by the midpoint C, that is, there is a line loss between the AC coupling point and the actual controlled point. Among them, the actual electrical signal corresponding to point C can be approximately considered as the sampling value of the first converter itself.

[0257] It can be understood that different selections of the controlled point may result in differences in the acquisition methods of the corresponding actual electrical signals.

[0258] In some embodiments, when the controlled point is an AC coupling point, the actual electrical signal is obtained according to the gateway sampling signal;

[0259] When the controlled point is not an AC coupling point, the actual electrical signal is obtained according to the AC side sampling signal of the power conversion device.

[0260] In this embodiment, if the controlled point is an AC coupling point, the sampling value at the AC coupling point can be directly obtained by the gateway device, and the sampled gateway sampling signal is determined as the actual electrical signal.

[0261] If the controlled point is a point such as Figure 8 shown by the midpoint C, the AC side sampling signals of each power conversion device (such as the sampling value of the first converter itself) can be used as the actual electrical signal corresponding to the controlled point.

[0262] As the number of paralleled units increases, the distance between the AC coupling point and the physical positions of each first converter will increase accordingly, resulting in an increase in the line loss between the AC coupling point and the actual controlled point C. Through the above sampling method, a more accurate actual electrical signal can be obtained.

[0263] According to the power control method of the power system provided by the embodiments of the present application, by selecting the corresponding acquisition method of the actual electrical signal according to the actual position of the controlled point, the influence of the line loss of the cable when the AC coupling point and the actual controlled point are not the same point on the control result can be reduced, the control accuracy and accuracy can be improved, so as to better maintain the balanced and stable operation of the system, and it has high control flexibility and adaptability.

[0264] In some embodiments,

[0265] In the case where the power system includes one power conversion device, the actual electrical signal is obtained according to the AC side sampling signal and / or the gateway sampling signal of the power conversion device;

[0266] In the case where the power system includes multiple power conversion devices, an actual electrical signal is obtained based on the AC-side sampling signals of at least one power conversion device, the average value of the AC-side sampling signals of each power conversion device, and the gateway sampling signal.

[0267] In this embodiment, for a single-machine scenario, the AC-side sampling signal of the power conversion device can be directly used as the actual electrical signal corresponding to the controlled point, or the gateway sampling signal collected by the gateway device can be determined as the actual electrical signal.

[0268] For a multi-machine scenario, the gateway sampling signal collected by the gateway device can be determined as the actual electrical signal; or the AC-side sampling signal of a certain power conversion device itself can be used as the actual electrical signal of the controlled point.

[0269] In some embodiments, for a multi-machine scenario, the average value of the AC-side sampling signals of some or all of the power conversion devices included in the power system can also be calculated, and the obtained average value can be determined as the actual electrical signal to further improve the authenticity of the actual electrical signal, thereby improving the control accuracy.

[0270] The following takes the power system as a single-machine system as an example for illustration.

[0271] In a single-machine scenario, the power system includes a power conversion device, and a power conversion device is connected to an external device, which can be a load or a third-party power generation device, etc.

[0272] In a single-machine scenario, the power of the third-party power generation device and / or the load is Pload, the first AC-side scheduling parameter value corresponding to the power conversion device is = Pac_1, Pac_1 = Pload, and the relationship between the first AC-side scheduling parameter value Pac_1 and the expected value of the DC-side power response Pdc includes the following multiple cases:

[0273] Single-machine case 1, Pac_1 = Pdc

[0274] In the case where the external device is an electrical device, such as when the external device is a load, it means that the DC-side power output capacity of the power conversion device is just sufficient to supply power to the load. At this time, the target AC electrical signal is determined as the first AC-side scheduling parameter value, so that the power conversion device adjusts the output of the first converter according to the first AC-side scheduling parameter value, so that the voltage reference Uref_device mapped by the target power conversion device to the AC coupling point = the first electrical signal reference value Uref_1.

[0275] At the AC coupling point, it is embodied as a closed-loop control of the actual electrical signal Upcc with the first electrical signal reference value Uref_1 as the voltage reference. While controlling Upcc to Uref_1, the power output of the first converter is balanced with the power of the electrical equipment.

[0276] When the external device is a power generation device, such as in the case of a third-party inverter, it means that the DC-side power absorption capacity of the power conversion device is just sufficient to consume the power of the third-party inverter. At this time, the target AC electrical signal is determined as the first AC-side scheduling parameter value, so that the power conversion device adjusts the output of the first converter according to the first AC-side scheduling parameter value, so that the voltage reference Uref_device mapped by the target power conversion device to the AC coupling point = the first electrical signal reference value Uref_1:

[0277] At the AC coupling point, it is embodied as a closed-loop control of the actual electrical signal Upcc with the first electrical signal reference value Uref_1 as the voltage reference. While controlling Upcc to Uref_1, the power input of the first converter is balanced with the power of the electrical equipment.

[0278] Single-machine case 2, Pac_1 < Pdc

[0279] When the external device is an electrical equipment, such as in the case of a load, it means that the expected output power of the DC side of the power conversion device is greater than the power of the load. Possible reasons include but are not limited to:

[0280] The power conversion device includes a photovoltaic device, and the maximum PV power is greater than the sum of Pac_1 and all rechargeable power on the DC side; specifically, it can include: (a) For a pure photovoltaic device: the expected value of the DC-side power response = the maximum power generation > Pac_1; (b) For a photovoltaic energy storage device, the expected value of the DC-side power response = the maximum power generation - the maximum charging power of the energy storage device > Pac_1, indicating that when the PV power can meet Pac_1, it simultaneously charges the energy storage device at full power, and there is still remaining PV power; (c) For a photovoltaic energy storage charging device, the expected value of the DC-side power response = the maximum power generation - the charging request power - the maximum charging power of the energy storage device > Pac_1, indicating that when the PV power meets Pac_1, it simultaneously charges the charging device and the energy storage device at full power, and there is still remaining PV power. (d) For a photovoltaic charging device, the expected value of the DC-side power response = the maximum power generation - the charging request power > Pac_1, indicating that when the PV power meets Pac_1, it simultaneously charges the charging device at full power, and there is still remaining PV power.

[0281] For the above situation, the target AC signal can be determined as the expected value of the DC-side power response to increase the power of the load, so that the power of the first converter and the power of the external device are as balanced as possible.

[0282] In some embodiments, an upper limit can also be set for the target AC signal to maximize the control power of the first converter on the basis that the external device can operate normally, so that more output is obtained for a high DC expected power and less output for a low one, in order to achieve energy distribution among devices. At the AC coupling point, it is embodied as a closed-loop control of Upcc with the second electrical signal reference value Uref_2 as the voltage reference, restricting the output of the inverter while raising Upcc to Uref_2, increasing the load power, and the first converter responding to the second AC signal Pac_2 to balance with the load power. Adjust the voltage expected reference value according to the second control reference to adjust the output of the inverter, that is: Uref_device = Uref_2.

[0283] When the external device is a power generation device, it means that the sum of the maximum charging powers of the rechargeable devices on the DC side is less than the total PV power, that is, the power input capacity of the power conversion device is insufficient to consume the power of the power generation device. Possible reasons include, but are not limited to: specifically, they may include: (a) For a pure photovoltaic device: the expected value of the DC-side power response = the maximum power generation > Pac_1; (b) For a photovoltaic and energy storage device, the expected value of the DC-side power response = the maximum power generation - the maximum charging power of the energy storage device > Pac_1, indicating that the energy storage device is fully charged, and there is still PV power remaining including that of the external device; (c) For a photovoltaic, energy storage and charging device, the expected value of the DC-side power response = the maximum power generation - the charging request power - the maximum charging power of the energy storage device > Pac_1, indicating that both the charging device and the energy storage device are fully charged, and there is still PV power remaining including that of the external device; (d) For a photovoltaic and charging device, the expected value of the DC-side power response = the maximum power generation - the charging request power > Pac_1, indicating that the charging device is fully charged, and there is still PV power remaining including that of the external device; (e) For an energy storage and charging device, the expected value of the DC-side power response = the charging request power - the maximum charging power of the energy storage device > Pac_1, indicating that both the charging device and the energy storage device are fully charged, and there is still PV power of the external device remaining.

[0284] For the above situation, the target AC signal can be determined as the expected value of the DC-side power response to reduce the power of the external power generation device, so that the power of the first converter and the power of the external device are as balanced as possible.

[0285] In some embodiments, the upper limit of the target AC power signal can also be defined to maximize the control power of the first converter on the basis that the external device can operate normally. At the AC coupling point, it is embodied as the closed-loop control of Upcc with Uref_2 as the voltage reference, raising Upcc to Uref_2, reducing the power of the power generation device, and the first converter responds to the second AC power signal Pac_2 to balance with the load power; that is: Uref_device = Uref_2.

[0286] Single-machine case 3, Pac_1 > Pdc

[0287] In the case where the external device is an electrical device, such as a load, it means that the expected output power of the DC side of the power conversion device is less than the power of the load. Possible reasons include, but are not limited to:

[0288] The sum of the maximum power generation power and all dischargeable power on the DC side is greater than the sum of the DC side and AC side load powers; specifically, it can include: (a) For a pure photovoltaic device: the expected value of the DC side power response = the maximum power generation power < Pac_1; (b) For a photovoltaic and energy storage device, the expected value of the DC side power response = the maximum power generation power + the maximum discharge power of the energy storage device < Pac_1, indicating that the sum of the PV power and the maximum discharge power of the energy storage is less than Pac_1; (c) For a photovoltaic, energy storage and charging device, the expected value of the DC side power response = the maximum power generation power - the charging request power + the maximum discharge power of the energy storage device < Pac_1, indicating that the sum of the PV power and the maximum discharge power of the energy storage is less than the sum of the charging power of the charging pile and Pac_1; (d) For a pure energy storage device, the expected value of the DC side power response = the maximum discharge power of the energy storage device < Pac_1, indicating that the maximum discharge power of the energy storage is less than Pac_1; (e) For a photovoltaic and charging device, the expected value of the DC side power response = the maximum power generation power - the charging request power < Pac_1, indicating that the PV power is less than the sum of the charging power of the charging pile and Pac_1; (f) For an energy storage and charging device, the expected value of the DC side power response = the maximum discharge power of the energy storage device - the charging request power < Pac_1, indicating that the maximum discharge power of the energy storage is less than the sum of the charging power of the charging pile and Pac_1.

[0289] For the above situations, the target AC power signal can be determined as the expected value of the DC side power response to reduce the load power and make the power of the first converter as balanced as possible with the power of the external device.

[0290] In some embodiments, the lower limit of the target AC signal can be defined to minimize the control power of the first converter on the basis that the external device can operate normally. At the AC coupling point, it is reflected as a closed-loop control of Upcc with the third AC signal Uref_3 as the voltage reference. While reducing Upcc to Uref_3, the load power is reduced, and the inverter responds to the third AC signal Pac_3 to balance with the load power; that is: Uref_device = Uref_3.

[0291] When the external device is a power generation device, it means that the expected input power of the power conversion device is greater than the power of the power generation device. The possible reasons include, but are not limited to:

[0292] The sum of the total PV power and all dischargeable power on the DC side is less than the sum of the DC side load powers; specifically, it can include: (a) For a photovoltaic energy storage charging device, the DC side power response expectation value = maximum power generation - charging request power + maximum discharge power of the energy storage device < Pac_1, indicating that the sum of the total PV power including the power generation device and the maximum discharge power of the energy storage is less than the charging power of the charging pile; (b) For a photovoltaic charging device, the DC side power response expectation value = maximum power generation - charging request power < Pac_1, and the total PV power including the power generation device is less than the charging power of the charging pile; (c) For an energy storage charging device, the DC side power response expectation value = maximum discharge power of the energy storage device - charging request power < Pac_1, indicating that the sum of the total PV power including the power generation device and the maximum discharge power of the energy storage is less than the charging power of the charging pile.

[0293] For the above situations, the target AC signal is determined as the DC side power response expectation value to increase the power generation of the external device and make the power of the first converter as balanced as possible with the power of the external device.

[0294] In some embodiments, the lower limit of the target AC signal can be defined to maximize the control power of the first converter on the basis that the external device can operate normally. At the AC coupling point, it is reflected as a closed-loop control of Upcc with the third AC signal Uref_3 as the voltage reference. While reducing Upcc to Uref_3, the output of the power generation device is increased, and its own power input is reduced. The first converter responds to the third AC signal Pac_3 to balance with the power generation load; at this time: Uref_device = Uref_3.

[0295] In some embodiments, in the case where multiple power conversion devices are included in a power system, the multiple power conversion devices can be regarded as a whole and equivalent to a power conversion device. The magnitude of the power between it and an external device determines the grid connection point voltage (controlled to one of Uref_1, Uref_2, and Uref_3), and also determines the total power output of the inverter (one of Pac_1, Pac_2, and Pac_3). On this basis, since devices in different operating states are equivalent to closed-loop control of Upcc with different voltage references at the AC coupling point, power distribution between devices is achieved, and balanced control in a multi-machine scenario is realized.

[0296] Taking the multi-machine scenario as an example below, the implementation effect of the method of the present application will be described.

[0297] Taking two parallel machines as an example, that is, two power conversion devices are respectively connected to the AC coupling point and connected to an external device through the AC coupling point. Hereinafter, device 1 and device 2 are used to represent these two power conversion devices. Among them, the first AC-side scheduling parameter value corresponding to device 1 is P1_ac, the first AC-side scheduling parameter value corresponding to device 2 is P2_dc, and the second AC-side scheduling parameter value corresponding to device 1 and device 2 as a whole is P1_ac + P2_ac; the expected value of the DC-side power response corresponding to device 1 is P1_dc, the expected value of the DC-side power response corresponding to device 2 is P2_dc, and the AC power corresponding to the external device is Pload, and P1_ac + P2_ac = Pload.

[0298] By judging the relationship between the first AC-side scheduling parameter value corresponding to each power conversion device and the expected value of the DC-side power response corresponding to this power conversion device, through the above steps 110 to 130, the target AC electrical signals corresponding to each power conversion device can be obtained respectively. During the operation of the power conversion device according to the corresponding target AC electrical signal, the voltage references mapped by device 1 and device 2 to the AC coupling point are respectively represented as Uref_device_1 and Uref_device_2.

[0299] Figure 9 Multiple situations are exemplified, and the following will specifically describe each situation.

[0300] I. The power conversion device operates according to its corresponding target AC electrical signal, and the voltage references mapped to the AC coupling point are as follows: the voltage reference corresponding to one device is the first electrical signal reference value Uref_1, and the voltage reference corresponding to the other device is the second electrical signal reference value Uref_2, such as parallel machine situation 4 and parallel machine situation 5.

[0301] The following takes Uref_device_1 = Uref_1; Uref_device_2 = Uref_2 as an example for illustration.

[0302] 1) When the external device is an electrical equipment, at the AC coupling point, it is reflected that device 1 performs closed-loop control on Upcc with Uref_1 as the voltage reference, and device 2 performs closed-loop control on Upcc with Uref_2 as the voltage reference. Since Uref_2 > Uref_1, device 2 can be enabled to output power preferentially.

[0303] When the actual electrical signal Upcc of the controlled point is controlled to Uref_2, it means that Pac_1 + Pac_2 < Pdc, where Pdc = P1_dc + P2_dc; the two parallel machines are equivalent to the single-machine case 2; at this time, device 1 has absorbed power to the maximum extent, and device 2 is scheduled by the second control signal of the total scheduling unit, indicating that on the basis of satisfying the sum of the load and the maximum absorbed power of device 1, device 2 still has a certain expected output power, that is, P2_out ≤ P2_dc; the power flow is as Figure 10 shown in Figure ① in the middle.

[0304] When the actual electrical signal Upcc of the controlled point is controlled to Uref_1, it means that Pac_1 + Pac_2 = Pdc, and the two parallel machines are equivalent to the single-machine case 1; at this time, device 2 has output all the expected output power on the DC side, and device 1 is scheduled by the first control signal of the total scheduling unit. Specifically, when the output power of device 2 is greater than the load power, device 1 and the load power jointly absorb the output power of device 2. At this time, the power flow is as Figure 10 shown in Figure ② in the middle; when the output power of device 2 is less than the load power, the remaining load power to be provided is provided by device 1. At this time, the power flow is as Figure 10 shown in Figure ③ in the middle.

[0305] 2) When the external device is a power generation equipment, at the AC coupling point, it is reflected that device 1 performs closed-loop control on Upcc with Uref_1 as the voltage reference, and device 2 performs closed-loop control on Upcc with Uref_2 as the voltage reference. Since Uref_2 > Uref_1, device 1 preferentially absorbs the power of the power generation equipment.

[0306] When the actual electrical signal Upcc of the controlled point is controlled to Uref_2, the two parallel machines are equivalent to the single-machine case 2. At this time, device 1 has absorbed power to the maximum extent, and device 2 is scheduled by the second control signal of the total scheduling unit, indicating that together with the power generation equipment, there is still a certain expected output power; specifically, when the power generation load power is greater than the maximum power absorption capacity of device 1, device 2 assists in absorbing power. At this time, the power flow is as Figure 11As shown in Figure ① in the Chinese figure; when the power of the power generation equipment is less than the maximum power absorption capacity of Equipment 1, Equipment 2 outputs power as much as possible, and the power flow is as follows Figure 11 As shown in Figure ② in the Chinese figure;

[0307] When the actual electrical signal Upcc of the controlled point is controlled to Uref_1, the two parallel-connected machines are equivalent to the single-machine case 1; at this time, Equipment 2 has output all the expected output power on the DC side, and Equipment 1 is scheduled by the first control signal of the total dispatching unit. Equipment 1 absorbs the power of the power generation load and the expected output power of Equipment 2. At this time, the power flow is as follows Figure 11 As shown in Figure ③ in the Chinese figure.

[0308] Second, the power conversion equipment operates according to its corresponding target AC electrical signal, and the voltage reference mapped to the AC coupling point is as follows: the voltage reference corresponding to one equipment is the first electrical signal reference value Uref_1, and the voltage reference corresponding to the other equipment is the third electrical signal reference value Uref_3, such as in parallel-connected machine case 6 and parallel-connected machine case 7.

[0309] The following takes Uref_device_1 = Uref_1; Uref_device_2 = Uref_3 as an example for illustration.

[0310] 1) When the external equipment is an electrical equipment, at the AC coupling point, it is reflected that Equipment 1 performs closed-loop control on Upcc with Uref_1 as the voltage reference, and Equipment 2 performs closed-loop control on Upcc with Uref_3 as the voltage reference. Equipment 1 gives priority to outputting power.

[0311] When the actual electrical signal Upcc of the controlled point is controlled to Uref_3, the two parallel-connected machines are equivalent to the single-machine case 3; at this time, Equipment 1 has output power to the maximum extent, and Equipment 2 is scheduled by the third control signal of the total dispatching unit, indicating that the power output by Equipment 1 still does not meet the expected absorption power of Equipment 2 and the load power; specifically, when the load power is greater than the maximum output power of Equipment 1, the power flow is as follows Figure 12 As shown in Figure ① in the Chinese figure; when the load power is less than the maximum output power of Equipment 1, at this time, by reducing Upcc to Uref_3, reducing the load power, and reducing the expected absorption power of Equipment 2, Equipment 1 is made to meet the power of Equipment 2 and the load to the maximum extent and reach a balance. At this time, the power flow is as follows Figure 12 As shown in Figure ② in the Chinese figure;

[0312] When the actual electrical signal Upcc of the controlled point is controlled to Uref_1, the two parallel machines are equivalent to the single-machine case 1; at this time, Device 2 has absorbed all the expected absorbed power on the DC side, and Device 1 is scheduled by the first control signal of the total dispatching unit, indicating that Device 1 can output the expected input power on the DC side of Device 2 while meeting the load power, that is, Device 1 supplies power to Device 2 and the load, achieving balance. At this time, the power flow is as Figure 12 shown in Figure ③ in the middle figure;

[0313] 2) When the external device is a power generation device, at this time, at the AC coupling point, it is reflected that Device 1 performs closed-loop control on Upcc with Uref_1 as the voltage reference, and Device 2 performs closed-loop control on Upcc with Uref_3 as the voltage reference. Device 2 preferentially absorbs the power of the power generation device.

[0314] When the actual electrical signal Upcc of the controlled point is controlled to Uref_3, the two parallel machines are equivalent to the single-machine case 3. At this time, Device 1 has output power to the maximum extent, and Device 2 is scheduled by the third control signal of the total dispatching unit, indicating that at this time, Device 1 and the power generation load have output power to the maximum extent, and still cannot meet the expected absorbed power on the DC side of Device 2. At this time, Device 2 reduces Upcc to Uref_2, while reducing the expected absorbed power, increasing the power of Device 1 and the power generation load, so that the maximum power output of Device 1 and the power generation load can reach balance with the expected absorbed power of Device 2, as Figure 13 shown in Figure ① in the middle figure;

[0315] When the actual electrical signal Upcc of the controlled point is controlled to Uref_1, the two parallel machines are equivalent to the single-machine case 1; at this time, Device 2 has absorbed all the expected absorbed power on the DC side, and Device 1 is scheduled by the first control signal of the total dispatching unit. Specifically, when the power of the power generation device is less than the expected absorbed power of Device 2, Device 1 assists in providing the power required by Device 2, as Figure 13 shown in Figure ② in the middle figure; when the power of the power generation device is greater than the expected absorbed power of Device 2, Device 1 absorbs the remaining power, as Figure 13 shown in Figure ③ in the middle figure, achieving balance.

[0316] III. The power conversion device operates according to its corresponding target AC electrical signal, and the voltage reference mapped to the AC coupling point is as follows: the voltage reference corresponding to one device is the second electrical signal reference value Uref_2, and the voltage reference corresponding to the other device is the third electrical signal reference value Uref_3, such as in parallel case 8 and parallel case 9.

[0317] Here, an example is given with Uref_device_1 = Uref_2; Uref_device_2 = Uref_3 for illustration.

[0318] 1) When the external device is an electrical equipment, at the AC coupling point, it is reflected that Device 1 performs closed-loop control on Upcc with Uref_2 as the voltage reference, and Device 2 performs closed-loop control on Upcc with Uref_3 as the voltage reference. Device 1 gives priority to power output.

[0319] When the actual electrical signal Upcc of the controlled point is controlled to Uref_1, the two parallel machines are equivalent to the single-machine case 1; at this time, both Device 1 and Device 2 reach their expected input or output power. At the same time, the load power can also be satisfied to achieve balance; when the expected power flow directions of Device 1 and Device 2 are the same, the power distribution is as Figure 14 shown in Figure ① in the middle; when the expected power flow directions of Device 1 and Device 2 are opposite, the power distribution is as Figure 14 shown in Figure ② in the middle;

[0320] When the actual electrical signal Upcc of the controlled point is controlled to Uref_2, the two parallel machines are equivalent to the single-machine case 2. At this time, Device 2 has absorbed power to the maximum capacity, and Device 1 is scheduled by the second control signal of the total scheduling unit. Moreover, on the basis of satisfying the sum of the load and the maximum absorbed power of Device 2, Device 1 still has a certain expected output power, and the power flow is as Figure 14 shown in Figure ③ in the middle;

[0321] When the actual electrical signal Upcc of the controlled point is controlled to Uref_3, the two parallel machines are equivalent to the single-machine case 3. At this time, Device 1 has output power to the maximum capacity, and Device 2 is scheduled by the third control signal of the total scheduling unit, indicating that the maximum output power of Device 1 still cannot meet the expected absorbed power of Device 2 and the load power; specifically, when the load power is greater than the maximum output power of Device 1, the power flow is as Figure 14 shown in Figure ④ in the middle; when the load power is less than the maximum output power of Device 1, at this time, by reducing Upcc to Uref_3, reducing the load power, and reducing the expected absorbed power of Device 2, Device 1 can satisfy the power of Device 2 and the load to the maximum capacity to achieve balance, and the power flow is as Figure 14 shown in Figure ⑤ in the middle.

[0322] 2) When the external device is a power generation equipment, at the AC coupling point, it is reflected that Device 1 performs closed-loop control on Upcc with Uref_2 as the voltage reference, and Device 2 performs closed-loop control on Upcc with Uref_3 as the voltage reference. Device 2 gives priority to absorbing the power of the power generation equipment.

[0323] When the actual electrical signal Upcc of the controlled point is controlled to Uref_1, the two parallel machines are equivalent to the single-machine case 1; at this time, both Device 1 and Device 2 reach their expected input or output power. At the same time, the load power can also be satisfied to achieve balance; when the expected power flow directions of Device 1 and Device 2 are the same, the power distribution is as Figure 15As shown in Figure ① in the middle figure; when the expected power flow directions of Device 1 and Device 2 are opposite, the power distribution is as follows Figure 15 shown in Figure ② in the middle figure;

[0324] When the actual electrical signal Upcc of the controlled point is controlled to Uref_2, the two parallel-connected machines are equivalent to the single-machine case 2. At this time, Device 2 has absorbed power to its maximum capacity, and Device 1 is scheduled by the second control signal of the total dispatching unit, indicating that together with the power generation equipment, it still has a certain expected output power; specifically, when the power of the power generation load is greater than the maximum power absorption capacity of Device 2, Device 1 assists in absorbing power, and the power flow direction is as follows Figure 15 shown in Figure ③ in the middle figure; when the power of the power generation equipment is less than the maximum power absorption capacity of Device 1, Device 2 outputs power as much as possible, and the power flow direction is as follows Figure 15 shown in Figure ④ in the middle figure;

[0325] When the actual electrical signal Upcc of the controlled point is controlled to Uref_3, the two parallel-connected machines are equivalent to the single-machine case 3. At this time, Device 1 has output power to its maximum capacity, and Device 2 is scheduled by the third control signal of the total dispatching unit, indicating that at this time, Device 1 and the power generation equipment together have output power to their maximum capacity, and still cannot meet the expected absorption power of the DC side of Device 2. At this time, Device 2 reduces Upcc to Uref_2, while reducing the expected absorption power, increasing the power of Device 1 and the power generation equipment, so that the maximum power output of Device 1 and the power generation equipment can reach balance with the expected absorption power of Device 2, as shown in Figure 15 Figure ⑤ in the middle figure.

[0326] IV. The power conversion device operates according to its corresponding target alternating current signal, and the voltage references mapped to the AC coupling point are all the first electrical signal reference value Uref_1, that is, the parallel-connected machine case 1: Uref_device_1 = Uref_device_2 = Uref_1.

[0327] 1) When the external device is an electrical equipment, the two parallel-connected machines are equivalent to the single-machine case 1, indicating that the sum of the power output capabilities of Device 1 and Device 2 is sufficient to supply power to the load. At this time, both Device 1 and Device 2 are scheduled by the first control signal of the total dispatching unit. At the AC coupling point, it is reflected as a closed-loop control of Upcc with Uref_1 as the voltage reference. While controlling Upcc to Uref_1, the power output of the inverter is balanced with the load power; the power flow direction at this time is as follows Figure 16 shown.

[0328] 2) When the external device is a power generation device, the two parallel units are equivalent to a single unit in Case 1, indicating that the sum of the power input capabilities of Device 1 and Device 2 is sufficient to absorb the power of the power generation device. At this time, both Device 1 and Device 2 are scheduled by the first control signal of the total scheduling unit. At the AC coupling point, it is manifested as a closed-loop control of Upcc with Uref_1 as the voltage reference. While controlling Upcc to be Uref_1, the power input of the inverter is balanced with the power of the power generation load; the power flow at this time is as shown in Figure 17 shown.

[0329] V. The power conversion device operates according to its corresponding target AC signal, and the voltage reference mapped to the AC coupling point is the second electrical signal reference value Uref_2, that is, parallel operation Case 2: Uref_device_1 = Uref_device_2 = Uref_2.

[0330] 1) When the external device is an electrical equipment, the two parallel units are equivalent to a single unit in Case 2, indicating that the sum of the expected output powers of Device 1 and Device 2 is greater than the load power. At this time, both Device 1 and Device 2 are scheduled by the second control signal of the total scheduling unit. At the AC coupling point, it is manifested as a closed-loop control of Upcc with Uref_2 as the voltage reference. While restricting the output of Device 1 and Device 2, Upcc is raised to Uref_2 to increase the load power, so that the power output of the inverter is balanced with the load power; the power flow at this time is as shown in Figure 18 shown;

[0331] 2) When the external device is a power generation device, the two parallel units are equivalent to a single unit in Case 2, indicating that the power input capabilities of Device 1 and Device 2 are insufficient to absorb the power of the power generation device. At this time, both Device 1 and Device 2 are scheduled by the third control signal of the total scheduling unit. At the AC coupling point, it is manifested as a closed-loop control of Upcc with Uref_2 as the voltage reference. Upcc is raised to Uref_2 to reduce the power of the power generation device, so that the power output of the inverter is balanced with the power of the power generation device; the power flow at this time is as shown in Figure 19 shown.

[0332] VI. The power conversion device operates according to its corresponding target AC signal, and the voltage reference mapped to the AC coupling point is the third electrical signal reference value Uref_3, that is, parallel operation Case 3: Uref_device_1 = Uref_device_2 = Uref_3.

[0333] 1) When the external device is an electrical device, the two parallel machines are equivalent to the single-machine case 3, indicating that the sum of the output capabilities of device 1 and device 2 is less than the load power. At this time, both device 1 and device 2 are scheduled by the third control signal of the total scheduling unit. At the AC coupling point, it is manifested as a closed-loop control of Upcc with Uref_3 as the voltage reference. While reducing Upcc to Uref_3, the load power is reduced, so that the power output of device 1 and device 2 reaches balance with the load power to the greatest extent; at this time, the power flow is as Figure 20 shown;

[0334] 2) When the external device is a power generation device, the two parallel machines are equivalent to the single-machine case 3, indicating that the expected input power of device 1 and device 2 is greater than the power generation device power. At this time, both device 1 and device 2 are scheduled by the third control signal of the total scheduling unit. At the AC coupling point, it is manifested as a closed-loop control of Upcc with Uref_3 as the voltage reference. While reducing Upcc to Uref_3, the output of the power generation device is increased and its own power input is reduced, so that the power input of the inverter reaches balance with the power generation device power; at this time, the power flow is as Figure 21 shown;

[0335] Through multiple tests and verifications by the inventor, by adopting the method provided in this application, it can be made that the larger the voltage control reference value equivalent at the AC coupling point, the more preferentially the power is output; on the contrary, the lower the voltage control reference value, the more preferentially the power is absorbed; thereby realizing the energy distribution and energy transfer between devices, preferentially outputting the expected output power, and also preferentially providing energy for the devices with expected input power, so as to realize the balanced control.

[0336] For the power control method of the power system provided in the embodiments of this application, the execution subject can be the power control device of the power system. In the embodiments of this application, taking the power control device of the power system executing the power control method of the power system as an example, the power control device of the power system provided in the embodiments of this application is described.

[0337] The embodiments of this application also provide a power control device for a power system.

[0338] As Figure 22 shown, the power system includes at least one power conversion device and a control module electrically connected to the power conversion device, and each power conversion device is respectively connected to the AC coupling point; each power conversion device includes a first converter and at least one DC module, and the power conversion device is used to be connected to an external device through the AC coupling point; each DC module in the same power conversion device is respectively connected to the first converter through the DC coupling point; the power control device of this power system includes: a first processing module 2210, a second processing module 2220, and a third processing module 2230.

[0339] The first processing module 2210 is configured to obtain the expected value of the DC-side power response corresponding to the target power conversion device in at least one power conversion device;

[0340] The second processing module 2220 is configured to determine the target AC electrical signal corresponding to the target power conversion device according to the expected value of the DC-side power response corresponding to the target power conversion device, the actual electrical signal at the AC coupling point, and the first electrical signal reference value of the AC coupling point;

[0341] The third processing module 2230 is configured to control the operating state of the target power conversion device based on the target AC electrical signal to adjust the power supply relationship between the power conversion devices.

[0342] According to the power control device of the power system provided by the embodiment of the present application, the target AC electrical signal of the first converter for adjusting the power conversion device is determined through the expected value of the DC-side power response corresponding to the target power conversion device and the first electrical signal reference value of the AC coupling point to control the first converter, so as to adjust the power supply relationship between the power conversion devices, so that the power conversion devices reach a balanced state.

[0343] In some embodiments, the second processing module 2220 may further be configured to:

[0344] Determine the first AC-side scheduling parameter value according to the actual electrical signal at the AC coupling point and the first electrical signal reference value;

[0345] Determine the target AC electrical signal corresponding to the target power conversion device according to the first AC-side scheduling parameter value and the expected value of the DC-side power response corresponding to the target power conversion device.

[0346] In some embodiments, the second processing module 2220 may further be configured to:

[0347] When the absolute value of the difference between the first AC-side scheduling parameter value and the expected value of the DC-side power response is less than the first threshold, determine the target AC electrical signal as the first AC-side scheduling parameter value;

[0348] When the absolute value of the difference between the first AC-side scheduling parameter value and the expected value of the DC-side power response is not less than the first threshold, determine the target AC electrical signal as the expected value of the DC-side power response.

[0349] In some embodiments, the second processing module 2220 may further be configured to:

[0350] Determine the target AC electrical signal based on the AC-side scheduling parameter value and the expected value of the DC-side power response;

[0351] Limit the upper and / or lower threshold of the target AC electrical signal to correct the target AC electrical signal.

[0352] In some embodiments, the second processing module 2220 may further be configured to:

[0353] When the target AC signal is greater than the second AC signal, update the target AC signal to the second AC signal, where the second AC signal is determined based on the actual electrical signal and the second electrical signal reference value of the AC coupling point, and the second electrical signal reference value is greater than the first electrical signal reference value.

[0354] In some embodiments, the second processing module 2220 may further be configured to:

[0355] When the target AC signal is less than the third AC signal, update the target AC signal to the third AC signal, where the third AC signal is determined based on the actual electrical signal and the third electrical signal reference value of the AC coupling point, and the third electrical signal reference value is less than the first electrical signal reference value.

[0356] In some embodiments, the second processing module 2220 may further be configured to:

[0357] Determine a first control signal according to the actual electrical signal of the AC coupling point and the first electrical signal reference value;

[0358] Convert the first control signal into a first AC-side scheduling parameter value for adjusting the first converter according to the first converter parameter corresponding to the target power conversion device.

[0359] In some embodiments, the second processing module 2220 may further be configured to:

[0360] Generate a first control signal according to a first difference between the actual electrical signal and the first electrical signal reference value.

[0361] In some embodiments, the third processing module 2230 may further be configured to perform closed-loop control on the target power conversion device based on the target AC signal and the actual electrical signal of the controlled point corresponding to the AC coupling point.

[0362] In some embodiments, the third processing module 2230 may further be configured to:

[0363] When the power system includes one power conversion device, obtain the actual electrical signal according to the AC-side sampling signal and / or the gateway sampling signal of the power conversion device;

[0364] When the power system includes multiple power conversion devices, obtain the actual electrical signal according to the AC-side sampling signals of at least one power conversion device, the average value of the AC-side sampling signals of each power conversion device, and the gateway sampling signal.

[0365] In some embodiments, the first processing module 2210 may further be configured to:

[0366] Determine the expected value of the sub - DC - side power response corresponding to each DC module according to the category of each DC module included in the target power conversion device;

[0367] Based on the sum of the expected values of the sub - DC - side power responses corresponding to each DC module, determine the expected value of the DC - side power response corresponding to the target power conversion device.

[0368] In some embodiments, the first processing module 2210 may further be configured to:

[0369] In the case where the DC module is a power generation device, determine the maximum power generation of the power generation device as the expected value of the sub - DC - side power response corresponding to the power generation device;

[0370] In the case where the DC module is an electrical equipment, determine the charging request power of the electrical equipment as the expected value of the sub - DC - side power response corresponding to the electrical equipment;

[0371] In the case where the DC module is an energy storage device, determine the expected value of the sub - DC - side power response corresponding to the energy storage device according to the category of other DC modules connected to the energy storage device and the first AC - side scheduling parameter value, where the first AC - side scheduling parameter value is determined according to the actual electrical signal at the AC coupling point and the first electrical signal reference value.

[0372] In some embodiments, the first processing module 2210 may further be configured to:

[0373] In the case where all other DC modules connected to the energy storage device are energy storage devices, or there are no other devices connected to the energy storage device, determine the expected value of the sub - DC - side power response corresponding to the energy storage device according to the absolute value of the maximum charge - discharge power of the energy storage device, the absolute value of the first AC - side scheduling parameter value, and the charge - discharge state corresponding to the maximum charge - discharge power;

[0374] In the case where other DC modules connected to the energy storage device include at least one of a power generation device and an electrical equipment, determine the energy storage scheduling power corresponding to the energy storage device according to the first AC - side scheduling parameter value and the expected values of the sub - DC - side power responses corresponding to each target module; the target module is a power generation device and / or an electrical equipment connected to the energy storage device;

[0375] Based on the energy storage scheduling power corresponding to the energy storage device, the charge - discharge state corresponding to the energy storage scheduling power, and the maximum charge - discharge power of the energy storage device, determine the expected value of the sub - DC - side power response corresponding to the energy storage device.

[0376] In some embodiments, the first processing module 2210 may further be configured to:

[0377] Determine the expected value of the sub - DC - side power response corresponding to the DC module according to at least one of the category of the DC module, the performance parameters of the DC module, the power scheduling of the DC module, and the charging request power corresponding to the DC module.

[0378] In some embodiments, the device may further include a fourth processing module, configured to determine a first electrical signal reference value based on the rated voltage of the power grid in the area where the power system is located, so as to enable the external devices connected to the power system to operate normally.

[0379] In some embodiments, the fourth processing module may further be configured to:

[0380] Determine a second electrical signal reference value based on the sampling error of the first converter and / or the maximum electrical signal of the external devices connected to the power system in the normal operating state, and the first electrical signal reference value is less than the second electrical signal reference value.

[0381] In some embodiments, the fourth processing module may further be configured to:

[0382] Determine a third electrical signal reference value based on the sampling error of the first converter and / or the minimum electrical signal of the external devices connected to the power system in the normal operating state, and the first electrical signal reference value is greater than the third electrical signal reference value.

[0383] In some embodiments, the fourth processing module may further be configured to:

[0384] Correspondingly set at least one of the first electrical signal reference value, the second electrical signal reference value, and the third electrical signal reference value according to the operating time period of the power system and / or the category of the external devices connected to the power system; wherein, the second electrical signal reference value is greater than the first electrical signal reference value, and the first electrical signal reference value is greater than the third electrical signal reference value.

[0385] The power control device of the power system in the embodiments of the present application can be an electronic device or a component in an electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal or other devices other than terminals. Exemplarily, the electronic device can be a mobile phone, a tablet computer, a laptop computer, a handheld computer, a vehicle-mounted electronic device, a Mobile Internet Device (MID), an augmented reality (AR) / virtual reality (VR) device, a robot, a wearable device, an ultra-mobile personal computer (UMPC), a netbook, or a personal digital assistant (PDA), etc. It can also be a server, a Network Attached Storage (NAS), a personal computer (PC), a television (TV), a teller machine, or a self-service machine, etc. The embodiments of the present application do not make specific limitations.

[0386] The power control device of the power system in the embodiments of the present application can be a device with an operating system. The operating system can be the Android operating system, the IOS operating system, or other possible operating systems. The embodiments of the present application do not make specific limitations.

[0387] The power control device provided by the embodiments of the present application can implement Figures 1 to 21 each process implemented by the method embodiments. To avoid repetition, details are not described herein again.

[0388] The embodiments of the present application also provide a power system.

[0389] As Figure 2 shown, the power conversion system includes: a first control module and at least one power conversion device.

[0390] Among them, each power conversion device is respectively connected to an AC coupling point. Each power conversion device includes a first converter and at least one DC module. The power conversion device is used to be connected to an external device through the AC coupling point; each DC module is respectively connected to the first converter through a DC coupling point, and the first control module is respectively connected to each first converter.

[0391] The power system operates according to the power control method of the power system described in any of the above embodiments.

[0392] According to the power system provided by the embodiments of the present application, the target AC signal of the first converter for adjusting the power conversion device is determined through the expected value of the DC side power response corresponding to the target power conversion device and the first electrical signal reference value of the AC coupling point, so as to control the first converter, and the power supply relationship between the power conversion devices is adjusted so that the power conversion devices reach a balanced state.

[0393] In some embodiments, the DC module may include: a DC converter and a power generation device, an electrical device, or an energy storage device connected to the DC converter.

[0394] In some embodiments, the first control module may include a main control module and at least one sub-control module.

[0395] In this embodiment, the main control module is electrically connected to each sub-control module. At least one sub-control module is arranged in one-to-one correspondence with at least one power conversion device.

[0396] In some embodiments, the sub-control module may be the first converter in the power conversion device, or may be a controller in the first converter, etc.

[0397] The main control module may be an external control module independent of each power conversion device, such as Figure 2 the total scheduling unit shown; or it may also be arranged inside any power conversion device, such as Figure 3 shown.

[0398] In the actual execution process, the execution logic of the main control module is as Figure 5 shown, and is used to determine the first control signal, the second control signal, and the third control signal respectively according to the actual electrical signal of the AC coupling point, the first electrical signal reference value, the second electrical signal reference value, and the third electrical signal reference value.

[0399] The execution logic of the sub-control module is as Figure 6 and Figure 7 shown, and is used to convert the first control signal into the first AC side scheduling parameter value for adjusting the first converter according to the first converter parameters corresponding to the target power conversion device, convert the second control signal into the second AC signal for adjusting the first converter, and convert the third control signal into the third AC signal for adjusting the first converter; determine the target AC signal corresponding to the target power conversion device according to the first AC side scheduling parameter value and the expected value of the DC side power response corresponding to the target power conversion device to control the first converter, and perform upper and lower limit threshold limiting on the target AC signal by using the second AC signal and the third AC signal.

[0400] The specific control logic has been described in the above embodiments and will not be elaborated here.

[0401] In some embodiments, such as Figure 23 shown, an embodiment of the present application further provides an electronic device 2300, including a processor 2301, a memory 2302, and a computer program stored on the memory 2302 and executable on the processor 2301. When the program is executed by the processor 2301, it implements each process of the power control method embodiment of the above power system and can achieve the same technical effects. To avoid repetition, it will not be elaborated here.

[0402] It should be noted that the electronic devices in the embodiments of the present application include the above-mentioned mobile electronic devices and non-mobile electronic devices.

[0403] An embodiment of the present application further provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements each process of the power control method embodiment of the above power system and can achieve the same technical effects. To avoid repetition, it will not be elaborated here.

[0404] Wherein, the processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes computer-readable storage media, such as computer read-only memory ROM, random access memory RAM, magnetic disk or optical disc, etc.

[0405] An embodiment of the present application further provides a computer program product, including a computer program. When the computer program is executed by a processor, it implements the power control method of the above power system.

[0406] Wherein, the processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes computer-readable storage media, such as computer read-only memory ROM, random access memory RAM, magnetic disk or optical disc, etc.

[0407] Another embodiment of the present application provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement each process of the power control method embodiment of the above power system and can achieve the same technical effects. To avoid repetition, it will not be elaborated here.

[0408] It should be understood that the chip mentioned in the embodiments of the present application may also be referred to as a system-on-chip, system chip, chip system, or system-on-chip, etc.

[0409] It should be noted that in this text, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising that element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, but may also include performing functions in a substantially simultaneous manner or in a reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Additionally, the features described with reference to certain examples may be combined in other examples.

[0410] Through the description of the above embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to enable a terminal (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present application.

[0411] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims, and all of them fall within the protection scope of the present application.

[0412] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0413] Although embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present application. The scope of the present application is defined by the claims and their equivalents.

Claims

1. A power control method for a power system, characterized in that The power system includes at least one power conversion device and a first control module electrically connected to the power conversion device. Each power conversion device is respectively connected to an AC coupling point; each power conversion device includes a first converter and at least one DC module, and the power conversion device is used to connect to an external device via the AC coupling point; In the same power conversion device, each DC module is respectively connected to the first converter via a DC coupling point; the method includes: The first control module obtains an expected value of the DC-side power response corresponding to the target power conversion device among the at least one power conversion device; According to the expected value of the DC-side power response corresponding to the target power conversion device, the actual electrical signal of the AC coupling point, and the first electrical signal reference value of the AC coupling point, determine the target AC electrical signal corresponding to the target power conversion device; Based on the target AC electrical signal, control the working state of the target power conversion device to adjust the power supply relationship between the power conversion devices; so that each power conversion device reaches balance; The determining the target AC electrical signal corresponding to the target power conversion device according to the expected value of the DC-side power response corresponding to the target power conversion device, the actual electrical signal of the AC coupling point, and the first electrical signal reference value of the AC coupling point includes: Determine a first AC-side scheduling parameter value according to the actual electrical signal of the AC coupling point and the first electrical signal reference value; According to the first AC-side scheduling parameter value and the expected value of the DC-side power response corresponding to the target power conversion device, determine the target AC electrical signal corresponding to the target power conversion device; The obtaining the expected value of the DC-side power response corresponding to the target power conversion device among the at least one power conversion device includes: According to the categories of the DC modules included in the target power conversion device, determine the expected values of the sub-DC-side power responses corresponding to the DC modules; Based on the sum of the expected values of the sub-DC-side power responses corresponding to the DC modules, determine the expected value of the DC-side power response corresponding to the target power conversion device; The working state includes a charge-discharge state and a charge-discharge power; The external device is an electrical equipment or a third-party power generation device; The power control method of the power system is used for an off-grid operation scenario.

2. The power control method of the power system according to claim 1, characterized in that, The determining the target AC electrical signal corresponding to the target power conversion device according to the first AC-side scheduling parameter value and the expected value of the DC-side power response corresponding to the target power conversion device includes: When the absolute value of the difference between the first AC-side scheduling parameter value and the expected value of the DC-side power response is less than a first threshold, determine the target AC electrical signal as the first AC-side scheduling parameter value; When the absolute value of the difference between the first AC-side scheduling parameter value and the expected value of the DC-side power response is not less than the first threshold, determine the target AC electrical signal as the expected value of the DC-side power response.

3. The power control method for the power system according to claim 1, wherein, Determining the target AC signal corresponding to the target power conversion device according to the first AC side scheduling parameter value and the expected DC side power response value corresponding to the target power conversion device includes: Determining the target AC signal based on the AC side scheduling parameter value and the expected DC side power response value; Performing upper and / or lower threshold limit on the target AC signal to correct the target AC signal.

4. The power control method of the power system according to claim 3, characterized in that The performing upper and / or lower threshold limit on the target AC signal to correct the target AC signal includes: When the target AC signal is greater than the second AC signal, updating the target AC signal to the second AC signal, where the second AC signal is determined based on the actual electrical signal and the second electrical signal reference value of the AC coupling point, and the second electrical signal reference value is greater than the first electrical signal reference value.

5. The power control method of the power system according to claim 3, characterized in that, The performing upper and / or lower threshold limit on the target AC signal to correct the target AC signal includes: When the target AC signal is less than the third AC signal, updating the target AC signal to the third AC signal, where the third AC signal is determined based on the actual electrical signal and the third electrical signal reference value of the AC coupling point, and the third electrical signal reference value is less than the first electrical signal reference value.

6. The power control method of the power system according to claim 1, characterized in that The determining the first AC side scheduling parameter value according to the actual electrical signal of the AC coupling point and the first electrical signal reference value includes: Determining a first control signal according to the actual electrical signal of the AC coupling point and the first electrical signal reference value; Converting the first control signal into the first AC side scheduling parameter value for adjusting the first converter according to the first converter parameter corresponding to the target power conversion device.

7. The power control method of the power system according to claim 6, wherein The determining the first control signal according to the actual electrical signal of the AC coupling point and the first electrical signal reference value includes: Generating the first control signal according to the first difference between the actual electrical signal and the first electrical signal reference value.

8. The power control method of the power system according to any one of claims 1-7, characterized in that The controlling the operating state of the target power conversion device based on the target AC signal includes: Performing closed-loop control on the target power conversion device based on the target AC signal and the actual electrical signal of the controlled point corresponding to the AC coupling point.

9. The power control method of the power system according to claim 8, wherein When the power system includes one such power conversion device, obtaining the actual electrical signal according to the AC side sampling signal and / or the gateway sampling signal of the power conversion device; When the power system includes multiple such power conversion devices, obtaining the actual electrical signal according to the AC side sampling signal of at least one of the power conversion devices, the average value of the AC side sampling signals of each power conversion device, and the gateway sampling signal.

10. The power control method of the power system according to claim 1, characterized in that, The determining the expected sub-DC side power response value corresponding to each DC module according to the categories of the DC modules included in the target power conversion device includes: When the DC module is a power generation device, determine the maximum power generation of the power generation device as the expected value of the sub-DC-side power response corresponding to the power generation device; When the DC module is an electrical equipment, determine the charging request power corresponding to the electrical equipment as the expected value of the sub-DC-side power response corresponding to the electrical equipment; When the DC module is an energy storage device, determine the expected value of the sub-DC-side power response corresponding to the energy storage device according to the category of other DC modules connected to the energy storage device and the first AC-side scheduling parameter value, where the first AC-side scheduling parameter value is determined according to the actual electrical signal at the AC coupling point and the first electrical signal reference value.

11. The power control method for the power system according to claim 10, characterized in that, When the DC module is an energy storage device, determining the expected value of the sub-DC-side power response corresponding to the energy storage device according to the category of other DC modules connected to the energy storage device and the first AC-side scheduling parameter value includes: When all other DC modules connected to the energy storage device are energy storage devices, or there are no other devices connected to the energy storage device, determine the expected value of the sub-DC-side power response corresponding to the energy storage device according to the absolute value of the maximum charge-discharge power corresponding to the energy storage device, the absolute value of the first AC-side scheduling parameter value, and the charge-discharge state corresponding to the maximum charge-discharge power; When at least one of the other DC modules connected to the energy storage device includes the power generation device and the electrical equipment, determine the energy storage scheduling power corresponding to the energy storage device according to the first AC-side scheduling parameter value and the expected value of the sub-DC-side power response corresponding to each target module; the target module is the power generation device and / or the electrical equipment connected to the energy storage device; Based on the energy storage scheduling power corresponding to the energy storage device, the charge-discharge state corresponding to the energy storage scheduling power, and the maximum charge-discharge power corresponding to the energy storage device, determine the expected value of the sub-DC-side power response corresponding to the energy storage device.

12. The power control method of the power system according to claim 1, characterized in that The expected value of the sub-DC-side power response corresponding to the DC module is determined according to at least one of the category of the DC module, the performance parameters of the DC module, the power scheduling of the DC module, and the charging request power corresponding to the DC module.

13. The power control method of the power system according to any one of claims 1-7, characterized in that The first electrical signal reference value is based on the rated voltage of the power grid in the area where the power system is located, and is used to enable external devices connected to the power system to operate normally.

14. The power control method of the power system according to any one of claims 1-7, characterized in that The second electrical signal reference value is based on the sampling error of the first converter and / or the maximum electrical signal of the external device connected to the power system under normal operating conditions, and the first electrical signal reference value is less than the second electrical signal reference value.

15. The power control method for the power system according to any one of claims 1-7, characterized in that, The third electrical signal reference value is based on the sampling error of the first converter and / or the minimum electrical signal of the external device connected to the power system under normal operating conditions, and the first electrical signal reference value is greater than the third electrical signal reference value.

16. The power control method of the power system according to any one of claims 1-7, characterized in that, Correspondingly set at least one of the first electrical signal reference value, the second electrical signal reference value, and the third electrical signal reference value according to the operating time period of the power system and / or the category of external devices connected to the power system; wherein, the second electrical signal reference value is greater than the first electrical signal reference value, and the first electrical signal reference value is greater than the third electrical signal reference value.

17. A power control device for a power system based on the power control method of the power system according to any one of claims 1-16, characterized in that, The power system includes at least one power conversion device, and each of the power conversion devices is connected to an AC coupling point respectively; each of the power conversion devices includes a first converter and at least one DC module, and the power conversion device is used to connect to an external device via the AC coupling point; In the same power conversion device, each of the DC modules is connected to the first converter via a DC coupling point respectively; the device includes: A first processing module, configured to obtain the expected value of the DC-side power response of the target power conversion device in the at least one power conversion device; A second processing module, configured to determine the target AC electrical signal corresponding to the target power conversion device according to the expected value of the DC-side power response of the target power conversion device, the actual electrical signal of the AC coupling point, and the first electrical signal reference value of the AC coupling point; A third processing module, configured to control the operating state of the target power conversion device based on the target AC electrical signal, so as to adjust the power supply relationship between the power conversion devices.

18. A power system, characterized in that, Including: A first control module; At least one power conversion device, and each of the power conversion devices is connected to an AC coupling point respectively; Each of the power conversion devices includes a first converter and at least one DC module, and the power conversion device is used to connect to an external device via the AC coupling point; each of the DC modules is connected to the first converter via a DC coupling point respectively, and the first control module is connected to each of the first converters respectively; The power system operates according to the power control method of the power system according to any one of claims 1-16.

19. The power system according to claim 18, characterized in that, The DC module includes: A DC converter; A power generation device, an electrical device, or an energy storage device connected to the DC converter.

20. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the power control method of the power system according to any one of claims 1-16.

21. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the power control method of the power system according to any one of claims 1-16.

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