Coordination control method and control device for charging pile access to direct current power distribution network

Abstract

The invention provides a coordination control method and control device for charging pile access to a DC power distribution network. According to the method, only the charging piles of which the SOC values are within the corresponding SOC value threshold range are considered to participate in coordination control, so that the charging piles are prevented from being overcharged and overdischarged, and the problem that the charging piles connected to the direct-current power distribution network are easily overcharged and overdischarged due to a coordination control method for connecting the charging piles to the direct-current power distribution network in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of coordinated control of charging piles connected to a DC distribution network, and in particular to a coordinated control method for charging piles connected to a DC distribution network, a coordinated control device for charging piles connected to a DC distribution network, a computer-readable storage medium and a computer program product. Background Art

[0002] In recent years, under the guidance of national policies, my country's electric vehicle industry has developed rapidly. In 2023, my country's sales of new energy vehicles, mainly electric vehicles, reached 9.495 million units, and the number of vehicles in use was 20.41 million, accounting for 6.1% of the total number of vehicles. The penetration rate jumped from 5.4% in 2020 to 31.6%. As the penetration rate of electric vehicles continues to rise, electric vehicles have gradually become a volatile load that cannot be ignored in the distribution network, posing a huge challenge to the stable operation of the power system.

[0003] The DC distribution network does not have problems such as reactive power, voltage, current, frequency and phase. It has advantages such as higher power supply reliability and higher charging power, which makes it more and more widely used. However, the DC distribution network composed of power electronic converters responds too fast, resulting in low inertia and weak anti-interference ability of the DC distribution network system. The switching of photovoltaic power stations, wind power stations and energy storage power stations, DC load disturbances, and the access and exit of electric vehicles will aggravate the fluctuation of the bus voltage of the DC distribution network and affect the power supply quality of the DC distribution network. Therefore, the existing technology studies the scenario of charging piles connected to the DC distribution network, so that the charging piles can provide a certain inertia and damping capacity similar to virtual synchronous machines, reduce the impact of electric vehicles on the DC distribution network, and can also reversely support the bus voltage of the DC distribution network. However, there are some problems in the coordinated control method of charging piles connected to the DC distribution network. The existing problems are as follows:

[0004] The differences in the SOC value status of different charging piles and the differences in the battery capacity configuration of different charging piles are often ignored. The charging piles are not reasonably allocated droop control and inertia damping according to the SOC value status, battery capacity configuration and bus voltage fluctuation of each charging pile. As a result, the charging piles connected to the DC distribution network are prone to overcharge and over-discharge, which damages the health of the battery and provides insufficient active support for the bus voltage of the DC distribution network.

[0005] Currently, there is no solution to the above problem. Summary of the invention

[0006] The main purpose of the present application is to provide a coordinated control method for connecting a charging pile to a DC distribution network, a coordinated control device for connecting a charging pile to a DC distribution network, a computer-readable storage medium and a computer program product, so as to at least solve the problem that the coordinated control method for connecting a charging pile to a DC distribution network in the prior art easily leads to overcharging and over-discharging of the charging pile connected to the DC distribution network.

[0007] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a coordinated control method for connecting a charging pile to a DC distribution network is provided, wherein a plurality of charging piles are electrically connected to a bus of the DC distribution network, and the method comprises: during the operation of the charging piles, obtaining the SOC value of each of the charging piles; when the SOC value of at least one of the charging piles is within the corresponding SOC value threshold range, obtaining an actual bus voltage value and a voltage deviation value, wherein the actual bus voltage value is the voltage value of the bus of the DC distribution network, and the voltage deviation value is the difference between the actual bus voltage value and a predetermined bus voltage value, and one of the charging piles has an SOC value threshold range, and when the SOC value of the charging pile is less than the minimum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an over-discharge state, and in the case where ... When the SOC value of the charging pile is greater than the maximum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an overcharge state, the over-discharge state indicates that the battery capacity of the charging pile is lower than the minimum value of the battery capacity of the charging pile, and the overcharge state indicates that the battery capacity of the charging pile is higher than the maximum value of the battery capacity of the charging pile; according to the SOC value of each charging pile, the maximum value of the battery capacity of each charging pile, the actual bus voltage value and the voltage deviation value, the droop control coefficient of each charging pile and the inertia damping parameter of each charging pile are determined respectively; based on the droop control coefficient of each charging pile and the inertia damping parameter of each charging pile, the operation of each charging pile is controlled respectively to reduce the difference between the actual bus voltage value and the predetermined bus voltage value.

[0008] Optionally, the inertial damping parameters include: a virtual damping coefficient and a virtual inertia, and based on the droop control coefficient of each charging pile and the inertial damping parameters of each charging pile, the operation of each charging pile is controlled respectively, including: according to the voltage deviation value, the droop control coefficient of each charging pile and The current command value of each charging pile is determined respectively, wherein: is the current command value of the i-th charging pile, is the droop control coefficient of the i-th charging pile, ΔU dcis the voltage deviation value; based on the current command value of each charging pile, the virtual damping coefficient of each charging pile and the virtual inertia of each charging pile, the operation of each charging pile is controlled respectively.

[0009] Optionally, in the process of respectively determining the droop control coefficient of each charging pile and the inertial damping parameter of each charging pile according to the SOC value of each charging pile, the maximum value of the battery capacity of each charging pile, the actual bus voltage value and the voltage deviation value, the method further comprises: determining a predetermined droop control coefficient as the droop control coefficient of the charging pile when the voltage deviation value satisfies a first predetermined condition, wherein the first predetermined condition is |ΔU dc |≤0.02U dcref , ΔUdc is the voltage deviation value, U dcref is the predetermined bus voltage value; when the voltage deviation value does not meet the first predetermined condition, the inertia margin of each charging pile is determined according to the SOC value of each charging pile and the maximum value of the battery capacity of each charging pile, wherein the inertia margin is a charging inertia margin, or a discharging inertia margin, the charging inertia margin indicates the adjustable degree of the absorbed power of the charging pile, and the discharging inertia margin indicates the adjustable degree of the output power of the charging pile; the droop control coefficient of the charging pile is determined according to the actual bus voltage value, the voltage deviation value, the inertia margin of each charging pile and the predetermined droop control coefficient.

[0010] Optionally, when the voltage deviation value does not meet the first predetermined condition, the inertia margin of each charging pile is determined according to the SOC value of each charging pile and the maximum value of the battery capacity of each charging pile, including: determining the inertia margin of each charging pile according to the SOC value of each charging pile, the maximum value of the battery capacity of each charging pile and Determine the equivalent SOC coefficient of each charging pile, where: is the equivalent SOC coefficient of the i-th charging pile, SOCi is the SOC value of the i-th charging pile, is the maximum value of the battery capacity of the i-th charging pile, and n is the total number of the charging piles connected to the DC distribution network; when the voltage deviation value does not meet the first predetermined condition but meets the second predetermined condition, according to the equivalent SOC coefficient and Determine the charging inertia margin of the charging pile, where k socmin represents the minimum equivalent SOC coefficient, k socmax is the maximum equivalent SOC coefficient, represents the charging inertia margin of the i-th charging pile, and the second predetermined condition is ΔUdc >0; when the voltage deviation value does not satisfy the first predetermined condition and does not satisfy the second predetermined condition, according to the equivalent SOC coefficient and Determine the discharge inertia margin of the charging pile, wherein: represents the discharge inertia margin of the i-th charging pile.

[0011] Optionally, the droop control coefficient of the charging pile is determined according to the actual bus voltage value, the voltage deviation value, the inertia margin of each charging pile, and the predetermined droop control coefficient, including: when the voltage deviation value does not satisfy the first predetermined condition but satisfies the second predetermined condition, the droop control coefficient of the charging pile is determined according to the actual bus voltage value, the voltage deviation value, the charging inertia margin of each charging pile, the predetermined droop control coefficient and Determine the alternative droop control coefficient of each charging pile respectively, where: represents the alternative droop control coefficient of the i-th charging pile, α is the first predetermined coefficient, β is the second predetermined coefficient, K0 is the predetermined droop control coefficient, represents the charging inertia margin of the i-th charging pile, U dc is the actual bus voltage value, ΔU dc is the voltage deviation value; when the voltage deviation value does not satisfy the first predetermined condition and does not satisfy the second predetermined condition, according to the actual bus voltage value, the voltage deviation value, the discharge inertia margin of each charging pile, the predetermined droop control coefficient and respectively determining the alternative droop control coefficient for each of the charging piles, Represents the discharge inertia margin of the i-th charging pile; when the alternative droop control coefficient of the charging pile is within the predetermined droop control coefficient range, the alternative droop control coefficient of the charging pile is determined to be the droop control coefficient of the charging pile; when the alternative droop control coefficient of the charging pile is less than the minimum value within the predetermined droop control coefficient range, the minimum value of the predetermined droop control coefficient range is determined to be the droop control coefficient of the charging pile; when the alternative droop control coefficient of the charging pile is greater than the maximum value within the predetermined droop control coefficient range, the maximum value of the predetermined droop control coefficient range is determined to be the droop control coefficient of the charging pile.

[0012] Optionally, in the process of respectively determining the droop control coefficient of each charging pile and the inertial damping parameter of each charging pile according to the SOC value of each charging pile, the maximum value of the battery capacity of each charging pile, the actual bus voltage value and the voltage deviation value, the method includes: determining the droop control coefficient of each charging pile and the inertial damping parameter of each charging pile according to the actual bus voltage value, the voltage deviation value and Determine the virtual damping coefficient of each charging pile, where D i is the virtual damping coefficient of the i-th charging pile, D0 is the predetermined virtual damping coefficient, c is the third predetermined coefficient, m1 is the fourth predetermined coefficient, U dc is the actual bus voltage value, ΔU dc is the voltage deviation value; according to the actual bus voltage value, the voltage deviation value and Determine the virtual inertia of each charging pile, where C i is the virtual inertia of the i-th charging pile, C0 is the predetermined virtual inertia, k1 is the fifth predetermined coefficient, k2 is the sixth predetermined coefficient, a is the seventh predetermined coefficient, b is the eighth predetermined coefficient, a+b=1, P i is the instantaneous power of the i-th charging pile, P iN is the rated power of the i-th charging pile.

[0013] Optionally, obtaining the SOC value of each charging pile includes: according to Determine the SOC value of each charging pile, is the initial SOC value of the i-th charging pile, is the instantaneous current of the i-th charging pile, t represents the current moment, and the initial SOC value is the SOC value of the charging pile before operation.

[0014] According to another aspect of the present application, a coordinated control device for connecting a charging pile to a DC distribution network is provided, wherein a plurality of charging piles are electrically connected to a bus of the DC distribution network, and the device comprises: a first acquisition unit, for acquiring an SOC value of each of the charging piles during operation of the charging piles; and a second acquisition unit, for acquiring an actual bus voltage value and a voltage deviation value when the SOC value of at least one of the charging piles is within a corresponding SOC value threshold range, wherein the actual bus voltage value is a voltage value of a bus of the DC distribution network, and the voltage deviation value is a difference between the actual bus voltage value and a predetermined bus voltage value, wherein one of the charging piles has an SOC value threshold range, and when the SOC value of the charging pile is less than the minimum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an over-discharge state, and in the When the SOC value of the charging pile is greater than the maximum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an overcharge state, the over-discharge state indicates that the battery capacity of the charging pile is lower than the minimum value of the battery capacity of the charging pile, and the overcharge state indicates that the battery capacity of the charging pile is higher than the maximum value of the battery capacity of the charging pile; a determination unit is used to determine the droop control coefficient of each charging pile and the inertia damping parameter of each charging pile according to the SOC value of each charging pile, the maximum value of the battery capacity of each charging pile, the actual bus voltage value and the voltage deviation value; a control unit is used to control the operation of each charging pile based on the droop control coefficient of each charging pile and the inertia damping parameter of each charging pile to reduce the difference between the actual bus voltage value and the predetermined bus voltage value.

[0015] According to another aspect of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium includes a stored program, wherein when the program is running, the device where the computer-readable storage medium is located is controlled to execute any one of the coordinated control methods for connecting a charging pile to a DC distribution network.

[0016] According to another aspect of the present application, a computer program product is provided, including a computer program / instruction, which, when executed by a processor, implements any one of the coordinated control methods for connecting a charging pile to a DC distribution network.

[0017] By applying the technical solution of the present application, first, during the operation of the charging pile, the SOC value of each charging pile is obtained. Then, when the SOC value of at least one charging pile is within the corresponding SOC value threshold range, the actual bus voltage value and the voltage deviation value are obtained. Thereafter, according to the SOC value of each charging pile, the battery capacity of each charging pile, the actual bus voltage value and the voltage deviation value, the droop control coefficient value of each charging pile and the inertia damping parameter value of each charging pile are respectively determined. Finally, based on the droop control coefficient value of each charging pile and the inertia damping parameter value of each charging pile, the operation of each charging pile is respectively controlled to reduce the difference between the actual bus voltage value and the predetermined bus voltage value. The present application only considers the charging piles whose SOC values ​​are within the corresponding SOC value threshold range to participate in the coordinated control to avoid overcharging and over-discharging of the charging piles, thereby solving the problem that the coordinated control method of connecting charging piles to a DC distribution network in the prior art easily causes overcharging and over-discharging of the charging piles connected to the DC distribution network. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of a DC power distribution network provided in an embodiment of the present application is shown;

[0019] Figure 2 A schematic flow chart of a first coordinated control method for connecting a charging pile to a DC distribution network provided in an embodiment of the present application is shown;

[0020] Figure 3 A schematic diagram of the control logic of a charging pile in the prior art provided according to an embodiment of the present application is shown;

[0021] FIG4( a) shows a schematic diagram of a first DC bus voltage provided according to an embodiment of the present application;

[0022] FIG4( b ) shows a schematic diagram of a second DC bus voltage provided according to an embodiment of the present application;

[0023] FIG4( c ) shows a schematic diagram of a third DC bus voltage provided according to an embodiment of the present application;

[0024] Figure 5 A schematic flow chart of a second coordinated control method for connecting a charging pile to a DC distribution network according to an embodiment of the present application is shown;

[0025] Figure 6 A structural block diagram of a coordinated control device for connecting a charging pile to a DC distribution network provided in accordance with an embodiment of the present application is shown. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0028] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0029] As introduced in the background technology, the coordinated control method for connecting charging piles to a DC distribution network in the prior art easily leads to overcharging and over-discharging of the charging piles connected to the DC distribution network. In order to solve the problem that the coordinated control method for connecting charging piles to a DC distribution network in the prior art easily leads to overcharging and over-discharging of the charging piles connected to the DC distribution network, the embodiments of the present application provide a coordinated control method for connecting charging piles to a DC distribution network, a coordinated control device for connecting charging piles to a DC distribution network, a computer-readable storage medium and a computer program product.

[0030] like Figure 1As shown, the DC distribution network in the prior art includes: a distribution network dispatching and control center, a data acquisition center, a plurality of charging piles, a plurality of electric vehicles, a DC load, an energy storage power station, a photovoltaic power station and a wind power station. The plurality of charging piles are electrically connected to the bus of the DC distribution network, and the charging piles are electrically connected to the electric vehicles. The switching of photovoltaic power stations, wind power stations and energy storage power stations, the disturbance of DC loads, the access and exit of electric vehicles will aggravate the fluctuation of the bus voltage of the DC distribution network. The data acquisition center is used to collect relevant information (SOC value, etc.) of the charging piles and the DC bus voltage. The distribution network dispatching and control center determines the droop control coefficient value of each charging pile and the inertia damping parameter value of each charging pile according to the relevant information (SOC value, etc.) of the charging piles and the DC bus voltage. Finally, based on the droop control coefficient value of each charging pile and the inertia damping parameter value of each charging pile, the operation of each charging pile is controlled to reduce the difference between the actual bus voltage value and the predetermined bus voltage value.

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0032] In this embodiment, a coordinated control method for connecting a charging pile to a DC distribution network is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0033] Figure 2 1 is a flow chart of a coordinated control method for connecting a charging pile to a DC distribution network according to an embodiment of the present application. Figure 2 As shown, the method comprises the following steps:

[0034] Step S201, during the operation of the charging piles, obtaining the SOC value of each of the charging piles;

[0035] In an optional solution, the above step S201 can be implemented as follows:

[0036] according to Determine the SOC value of each of the above charging piles, is the initial SOC value of the i-th charging pile, is the instantaneous current of the i-th charging pile, t represents the current moment, and the initial SOC value is the SOC value of the charging pile before operation.

[0037] Specifically, the instantaneous current of the charging pile is the current instantaneously absorbed by the charging pile, or the current instantaneously released by the charging pile.

[0038] Step S202, when the SOC value of at least one of the above charging piles is within the corresponding SOC value threshold range, obtaining the actual bus voltage value and the voltage deviation value;

[0039] Wherein, the actual bus voltage value is the voltage value of the bus of the DC distribution network, the voltage deviation value is the difference between the actual bus voltage value and the predetermined bus voltage value, one of the charging piles has an SOC value threshold range, when the SOC value of the charging pile is less than the minimum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an over-discharge state, when the SOC value of the charging pile is greater than the maximum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an over-charge state, the over-discharge state indicates that the battery capacity of the charging pile is lower than the minimum value of the battery capacity of the charging pile, and the over-charge state indicates that the battery capacity of the charging pile is higher than the maximum value of the battery capacity of the charging pile;

[0040] Specifically, when the SOC value of the i-th charging pile is In the case of , the i-th charging pile is allowed to participate in coordinated control to avoid overcharging or overdischarging of the i-th charging pile. is the minimum value of the battery capacity of the i-th charging pile, is the maximum value of the battery capacity of the i-th charging pile.

[0041] Step S203, determining the droop control coefficient of each of the above-mentioned charging piles and the inertial damping parameter of each of the above-mentioned charging piles according to the SOC value of each of the above-mentioned charging piles, the maximum value of the battery capacity of each of the above-mentioned charging piles, the above-mentioned actual bus voltage value and the above-mentioned voltage deviation value;

[0042] In an optional solution, in the above step S203, the above method further includes:

[0043] Step S2031: when the voltage deviation value satisfies a first predetermined condition, determining a predetermined droop control coefficient as the droop control coefficient of the charging pile, wherein the first predetermined condition is |ΔU dc |≤0.02U dcref , ΔU dc is the above voltage deviation value, U dcref is the above-mentioned predetermined bus voltage value;

[0044] Specifically, if the voltage deviation value satisfies the first predetermined condition, it indicates that the actual bus voltage value is normal.

[0045] Step S2032, when the voltage deviation value does not satisfy the first predetermined condition, the inertia margin of each of the charging piles is determined according to the SOC value of each of the charging piles and the maximum value of the battery capacity of each of the charging piles, wherein the inertia margin is a charging inertia margin or a discharging inertia margin, the charging inertia margin indicates the adjustable degree of the absorbed power of the charging pile, and the discharging inertia margin indicates the adjustable degree of the output power of the charging pile;

[0046] Specifically, the larger the charging inertia margin is, the higher the degree of adjustability of the absorption power of the charging pile is, and the larger the discharging inertia margin is, the higher the degree of adjustability of the output power of the charging pile is.

[0047] In an optional solution, the above step S2032 may be implemented as follows:

[0048] According to the SOC value of each of the above charging piles, the maximum value of the battery capacity of each of the above charging piles and Determine the equivalent SOC coefficient of each of the above charging piles, where: is the equivalent SOC coefficient of the i-th charging pile, SOC i is the SOC value of the i-th charging pile, is the maximum value of the battery capacity of the i-th charging pile, and n is the total number of the charging piles connected to the DC distribution network;

[0049] When the voltage deviation value does not satisfy the first predetermined condition but satisfies the second predetermined condition, according to the equivalent SOC coefficient and Determine the charging inertia margin of each of the above charging piles, where k socmin represents the minimum equivalent SOC coefficient mentioned above, k socmax is the maximum equivalent SOC coefficient mentioned above, represents the charging inertia margin of the i-th charging pile, and the second predetermined condition is ΔU dc >0;

[0050] Specifically, when the voltage deviation value does not meet the first predetermined condition but meets the second predetermined condition, it is determined that the bus voltage of the DC distribution network is too high. At this time, the charging inertia margin is adjusted, and the absorption power of each charging pile is coordinated and controlled according to the charging inertia margin, so that the charging pile with a high charging inertia margin can absorb more electricity during discharge, so that within the adjustable capacity range of the charging pile, the bus voltage of the DC distribution network is reduced to the greatest extent, ensuring that the charging pile has sufficient active support for the bus voltage of the DC distribution network.

[0051] When the voltage deviation value does not satisfy the first predetermined condition and the second predetermined condition, the equivalent SOC coefficient of each charging pile is Determine the above-mentioned discharge inertia margin of each of the above-mentioned charging piles, wherein: represents the discharge inertia margin of the i-th charging pile.

[0052] Specifically, when the voltage deviation value does not meet the first predetermined condition and does not meet the second predetermined condition, it is determined that the bus voltage of the DC distribution network is low. At this time, the discharge inertia margin is adjusted, and the output power of each charging pile is coordinated and controlled according to the discharge inertia margin, so that the charging pile with a high discharge inertia margin can discharge more electricity during discharge, so that within the adjustable capacity range of the charging pile, the bus voltage of the DC distribution network is maximized, ensuring that the charging pile has sufficient active support for the bus voltage of the DC distribution network.

[0053] Step S2033, determining the droop control coefficients of the charging piles respectively according to the actual bus voltage value, the voltage deviation value, the inertia margin of each of the charging piles and the predetermined droop control coefficient.

[0054] In an optional solution, the above step S2033 can be implemented as follows:

[0055] When the voltage deviation value does not satisfy the first predetermined condition but satisfies the second predetermined condition, the actual bus voltage value, the voltage deviation value, the charging inertia margin of each charging pile, the predetermined droop control coefficient and Determine the alternative droop control coefficients of the above charging piles respectively, where: represents the alternative droop control coefficient of the i-th charging pile, α is the first predetermined coefficient, β is the second predetermined coefficient, K0 is the predetermined droop control coefficient, represents the charging inertia margin of the i-th charging pile, U dc is the actual bus voltage value mentioned above, ΔU dc is the above voltage deviation value;

[0056] Specifically, when the voltage deviation value does not meet the first predetermined condition but meets the second predetermined condition, it is determined that the bus voltage of the DC distribution network is too high. At this time, the droop control coefficient of each charging pile is determined according to the actual bus voltage value, the voltage deviation value, and the charging inertia margin of each charging pile. The absorption power of each charging pile is coordinated and controlled according to the droop control coefficient, so that the charging pile with a high charging inertia margin can absorb more electricity during discharge, so that the bus voltage of the DC distribution network is minimized within the adjustable capacity range of each charging pile. According to the SOC value status, battery capacity configuration and bus voltage fluctuation of each charging pile, the charging piles are reasonably allocated droop control to ensure that the charging piles have sufficient active support for the bus voltage of the DC distribution network.

[0057] When the voltage deviation value does not satisfy the first predetermined condition and does not satisfy the second predetermined condition, the actual bus voltage value, the voltage deviation value, the discharge inertia margin of each charging pile, the predetermined droop control coefficient and Determine the above-mentioned alternative droop control coefficients of each of the above-mentioned charging piles respectively, represents the discharge inertia margin of the i-th charging pile;

[0058] Specifically, when the voltage deviation value does not meet the first predetermined condition and does not meet the second predetermined condition, it is determined that the bus voltage of the DC distribution network is low. At this time, the droop control coefficient of each charging pile is determined according to the actual bus voltage value, the voltage deviation value, and the charging inertia margin of each charging pile. The output power of each charging pile is coordinated and controlled according to the droop control coefficient of each charging pile, so that the charging pile with a high discharge inertia margin can discharge more electricity during discharge, so that the bus voltage of the DC distribution network is maximized within the adjustable capacity range of each charging pile. According to the SOC value status, battery capacity configuration and bus voltage fluctuation of each charging pile, the charging piles are reasonably allocated droop control to ensure that the charging piles have sufficient active support for the bus voltage of the DC distribution network.

[0059] When the above-mentioned alternative droop control coefficient of the above-mentioned charging pile is within the predetermined droop control coefficient range, the above-mentioned alternative droop control coefficient of the above-mentioned charging pile is determined to be the above-mentioned droop control coefficient of the above-mentioned charging pile; when the above-mentioned alternative droop control coefficient of the above-mentioned charging pile is less than the minimum value within the predetermined droop control coefficient range, the minimum value of the predetermined droop control coefficient range is determined to be the above-mentioned droop control coefficient of the above-mentioned charging pile; when the above-mentioned alternative droop control coefficient of the above-mentioned charging pile is greater than the maximum value within the predetermined droop control coefficient range, the maximum value of the predetermined droop control coefficient range is determined to be the above-mentioned droop control coefficient of the above-mentioned charging pile.

[0060] Specifically, in order to ensure the stable operation of the charging pile, the droop control coefficient of each charging pile needs to be within a predetermined droop control coefficient range.

[0061] In an optional solution, in the above step S203, the above method further includes:

[0062] According to the above actual bus voltage value, the above voltage deviation value and Determine the virtual damping coefficient of each charging pile, where D i is the virtual damping coefficient of the i-th charging pile, D0 is the predetermined virtual damping coefficient, c is the third predetermined coefficient, m1 is the fourth predetermined coefficient, U dc is the actual bus voltage value mentioned above, ΔU dc is the above voltage deviation value;

[0063] Specifically, reasonable damping distribution is performed on the charging piles according to the bus voltage fluctuation of the DC distribution network.

[0064] According to the above actual bus voltage value, the above voltage deviation value and Determine the virtual inertia of each of the above charging piles, where C i is the virtual inertia of the i-th charging pile, C0 is the predetermined virtual inertia, k1 is the fifth predetermined coefficient, k2 is the sixth predetermined coefficient, a is the seventh predetermined coefficient, b is the eighth predetermined coefficient, a+b=1, P i is the instantaneous power of the i-th charging pile, P iN is the rated power of the i-th charging pile mentioned above.

[0065] Specifically, the inertia of the charging piles is reasonably distributed according to the bus voltage fluctuation of the DC distribution network.

[0066] Step S204, based on the droop control coefficient of each of the above-mentioned charging piles and the inertial damping parameter of each of the above-mentioned charging piles, respectively control the operation of each of the above-mentioned charging piles to reduce the difference between the above-mentioned actual bus voltage value and the above-mentioned predetermined bus voltage value.

[0067] Specifically, the present application determines the droop control coefficient value and the inertia damping parameter value of each charging pile according to the SOC value of each charging pile, the battery capacity of each charging pile, the actual bus voltage value and the voltage deviation value, that is, the charging piles are reasonably allocated droop control and inertia damping according to the SOC value status, battery capacity configuration and bus voltage fluctuation of the DC distribution network of each charging pile, so as to reasonably coordinate the active support of the bus voltage of the DC distribution network by each charging pile, so as to ensure sufficient active support for the bus voltage of the DC distribution network.

[0068] In an optional solution, the inertial damping parameter value includes: a virtual damping coefficient value and a virtual inertia value, and the step S204 can be implemented as follows:

[0069] According to the voltage deviation value, the droop control coefficient of each charging pile and The current command value of each of the above charging piles is determined respectively, wherein: is the current command value of the i-th charging pile, is the droop control coefficient of the i-th charging pile, ΔU dc is the above voltage deviation value;

[0070] Based on the current command value of each of the charging piles, the virtual damping coefficient of each of the charging piles, and the virtual inertia of each of the charging piles, the operation of each of the charging piles is controlled respectively.

[0071] Specifically, Figure 3 As shown, the control logic of the charging pile in the prior art includes: a virtual synchronous machine unit, a voltage PI controller, a current PI controller and a pulse generating unit, wherein the control logic of the virtual synchronous machine unit is: in, is the voltage command value, I i is the instantaneous current of the i-th charging pile, similar to the input of the virtual synchronous machine unit: ,I i , D i , C i and U dc , the output is ,Will Input is sequentially input into the voltage PI controller, the current PI controller and the pulse generating unit to obtain the PWM control signal of the i-th charging pile, so as to realize reasonable droop control distribution and inertia damping distribution of the charging pile according to the SOC value state, battery capacity configuration and bus voltage fluctuation of each charging pile, so as to reasonably coordinate the active support of the bus voltage of the DC distribution network by each charging pile, so as to ensure sufficient active support for the bus voltage of the DC distribution network, wherein the voltage PI controller, the current PI controller and the pulse generating unit are all existing technologies and therefore will not be elaborated here.

[0072] Through the above embodiments, first, during the operation of the charging pile, the SOC value of each charging pile is obtained, and then, when the SOC value of at least one charging pile is within the corresponding SOC value threshold range, the actual bus voltage value and the voltage deviation value are obtained. After that, according to the SOC value of each charging pile, the battery capacity of each charging pile, the actual bus voltage value and the voltage deviation value, the droop control coefficient value of each charging pile and the inertia damping parameter value of each charging pile are respectively determined. Finally, based on the droop control coefficient value of each charging pile and the inertia damping parameter value of each charging pile, the operation of each charging pile is respectively controlled to reduce the difference between the actual bus voltage value and the predetermined bus voltage value. The present application only considers the charging piles whose SOC values ​​are within the corresponding SOC value threshold range to participate in the coordinated control to avoid overcharging and over-discharging of the charging piles, thereby solving the problem that the coordinated control method of connecting charging piles to the DC distribution network in the prior art easily causes overcharging and over-discharging of the charging piles connected to the DC distribution network.

[0073] Specifically, in order to verify the effectiveness of the coordinated control method for connecting the charging pile to the DC distribution network of the present application, a simulation model was built through the Matlab / Simulink platform. The DC distribution network maintained a source side power of 40 kW, and the DC load was initially 40 kW, which increased to 50 kW in 0.1 seconds and decreased to 32 kW in 0.2 seconds, thereby simulating the DC load disturbance process of the tributary distribution network. At the same time, two batteries with different SOC values ​​and different battery capacities were used to simulate the connection of electric vehicle batteries to the charging pile for charging. Figures 4(a), 4(b) and 4(c) are respectively the DC bus voltage when the virtual synchronous machine control method is adopted, the DC bus voltage when the adaptive inertia damping virtual synchronous machine control method is adopted, and the DC bus voltage when the coordinated control method for connecting the charging pile to the DC distribution network of the present application is adopted. It can be seen that the coordinated control method for connecting the charging pile to the DC distribution network of the present application can effectively reduce the overshoot of the DC bus voltage and improve the recovery speed of the bus voltage.

[0074] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the implementation process of the coordinated control method for connecting the charging pile to the DC distribution network of the present application will be described in detail below in combination with specific embodiments.

[0075] This embodiment relates to a specific coordinated control method for connecting a charging pile to a DC distribution network. Figure 5 As shown, the following steps are included:

[0076] Step S1: During the operation of the charging pile, the SOC value of each charging pile is obtained;

[0077] Step S2: when the SOC value of at least one charging pile is within the corresponding SOC value threshold range, obtaining the actual bus voltage value and the voltage deviation value;

[0078] Step S3: Calculate the droop control coefficient of each charging pile:

[0079] When the voltage deviation value satisfies |ΔU dc |≤0.02U dcref In the case of , determining the predetermined droop control coefficient as the droop control coefficient of the charging pile;

[0080] When the voltage deviation value does not meet |ΔU dc |≤0.02U dcref And satisfy ΔU dc >0, according to the SOC value of each charging pile, the maximum value of the battery capacity of each charging pile and Determine the equivalent SOC coefficient of each charging pile, based on the equivalent SOC coefficient of each charging pile and Determine the charging inertia margin of each charging pile according to the actual bus voltage value, voltage deviation value, charging inertia margin of each charging pile, predetermined droop control coefficient and Determine the alternative droop control coefficient for each charging pile respectively;

[0081] When the voltage deviation value does not meet |ΔU dc |≤0.02U dcref And does not satisfy ΔU dc >0, according to the SOC value of each charging pile, the maximum value of the battery capacity of each charging pile and Determine the equivalent SOC coefficient of each charging pile, based on the equivalent SOC coefficient of each charging pile and Determine the discharge inertia margin of each charging pile, based on the actual bus voltage value, voltage deviation value, discharge inertia margin of each charging pile, predetermined droop control coefficient and Determine the alternative droop control coefficient for each charging pile respectively;

[0082] In the case where the alternative droop control coefficient of the charging pile is within the predetermined droop control coefficient range, the alternative droop control coefficient of the charging pile is determined to be the droop control coefficient of the charging pile; in the case where the alternative droop control coefficient of the charging pile is less than the minimum value within the predetermined droop control coefficient range, the minimum value of the predetermined droop control coefficient range is determined to be the droop control coefficient of the charging pile; in the case where the alternative droop control coefficient of the charging pile is greater than the maximum value within the predetermined droop control coefficient range, the maximum value of the predetermined droop control coefficient range is determined to be the droop control coefficient of the charging pile;

[0083] Step S5: Based on the voltage deviation value, the droop control coefficient of each charging pile and Determine the current command value of each charging pile respectively;

[0084] Step S6: Calculate the droop control coefficient of each charging pile and the inertial damping parameter of each charging pile:

[0085] According to the actual bus voltage value, voltage deviation value and Determine the virtual damping coefficient of each charging pile;

[0086] According to the actual bus voltage value, voltage deviation value and Determine the virtual inertia of each charging pile.

[0087] Step S7: Based on the current command value of each charging pile, the virtual damping coefficient of each charging pile and the virtual inertia of each charging pile, the operation of each charging pile is controlled respectively.

[0088] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described may be executed in an order different from that shown here.

[0089] The embodiment of the present application also provides a coordination control device for accessing a charging pile to a DC distribution network. It should be noted that the coordination control device for accessing a charging pile to a DC distribution network in the embodiment of the present application can be used to execute the coordination control method for accessing a charging pile to a DC distribution network provided in the embodiment of the present application. The device is used to implement the above-mentioned embodiments and preferred implementation modes, and those that have been described will not be repeated. As used below, the term "module" can implement a combination of software and / or hardware for a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceived.

[0090] The following is an introduction to the coordinated control device for connecting a charging pile to a DC distribution network provided in an embodiment of the present application.

[0091] Figure 6 It is a structural block diagram of a coordinated control device for connecting a charging pile to a DC distribution network according to an embodiment of the present application.

[0092] like Figure 6 As shown, the device comprises:

[0093] A first acquisition unit 10 is used to acquire the SOC value of each of the above charging piles during the operation of the above charging piles;

[0094] In an optional solution, the first acquisition unit is used to:

[0095] according to Determine the SOC value of each of the above charging piles, is the initial SOC value of the i-th charging pile, is the instantaneous current of the i-th charging pile, t represents the current moment, and the initial SOC value is the SOC value of the charging pile before operation.

[0096] Specifically, the instantaneous current of the charging pile is the current instantaneously absorbed by the charging pile, or the current instantaneously released by the charging pile.

[0097] A second acquisition unit 20 is used to acquire an actual bus voltage value and a voltage deviation value when the SOC value of at least one of the above charging piles is within a corresponding SOC value threshold range;

[0098] Wherein, the actual bus voltage value is the voltage value of the bus of the DC distribution network, the voltage deviation value is the difference between the actual bus voltage value and the predetermined bus voltage value, one of the charging piles has an SOC value threshold range, when the SOC value of the charging pile is less than the minimum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an over-discharge state, when the SOC value of the charging pile is greater than the maximum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an over-charge state, the over-discharge state indicates that the battery capacity of the charging pile is lower than the minimum value of the battery capacity of the charging pile, and the over-charge state indicates that the battery capacity of the charging pile is higher than the maximum value of the battery capacity of the charging pile;

[0099] Specifically, when the SOC value of the i-th charging pile is In the case of , the i-th charging pile is allowed to participate in coordinated control to avoid overcharging or overdischarging of the i-th charging pile. is the minimum value of the battery capacity of the i-th charging pile, is the maximum value of the battery capacity of the i-th charging pile.

[0100] The determination unit 30 is used to determine the droop control coefficient of each of the above-mentioned charging piles and the inertial damping parameter of each of the above-mentioned charging piles according to the SOC value of each of the above-mentioned charging piles, the maximum value of the battery capacity of each of the above-mentioned charging piles, the above-mentioned actual bus voltage value and the above-mentioned voltage deviation value;

[0101] In an optional solution, the determining unit includes:

[0102] The first determining module is used to determine the predetermined droop control coefficient as the droop control coefficient of the charging pile when the voltage deviation value satisfies a first predetermined condition, wherein the first predetermined condition is |ΔU dc |≤0.02U dcref , ΔU dc is the above voltage deviation value, U dcref is the above-mentioned predetermined bus voltage value;

[0103] Specifically, if the voltage deviation value satisfies the first predetermined condition, it indicates that the actual bus voltage value is normal.

[0104] A second determination module is used to determine the inertia margin of each of the above-mentioned charging piles according to the SOC value of each of the above-mentioned charging piles and the maximum value of the battery capacity of each of the above-mentioned charging piles when the above-mentioned voltage deviation value does not meet the above-mentioned first predetermined condition, wherein the above-mentioned inertia margin is a charging inertia margin or a discharging inertia margin, the above-mentioned charging inertia margin indicates the adjustable degree of the absorption power of the above-mentioned charging pile, and the above-mentioned discharging inertia margin indicates the adjustable degree of the output power of the above-mentioned charging pile;

[0105] Specifically, the larger the charging inertia margin is, the higher the degree of adjustability of the absorption power of the charging pile is, and the larger the discharging inertia margin is, the higher the degree of adjustability of the output power of the charging pile is.

[0106] In an optional solution, the first determining module includes:

[0107] The first determination submodule is used to determine the maximum value of the battery capacity of each of the above charging piles according to the SOC value of each of the above charging piles and Determine the equivalent SOC coefficient of each of the above charging piles, where: is the equivalent SOC coefficient of the i-th charging pile, SOC i is the SOC value of the i-th charging pile, is the maximum value of the battery capacity of the i-th charging pile, and n is the total number of the charging piles connected to the DC distribution network;

[0108] The second determination submodule is used to determine the voltage deviation value according to the equivalent SOC coefficient and the equivalent SOC coefficient of each charging pile when the voltage deviation value does not meet the first predetermined condition but meets the second predetermined condition. Determine the charging inertia margin of the charging pile, where k socmin represents the minimum equivalent SOC coefficient mentioned above, k socmax is the maximum equivalent SOC coefficient mentioned above, represents the charging inertia margin of the i-th charging pile, and the second predetermined condition is ΔU dc >0;

[0109] Specifically, when the voltage deviation value does not meet the first predetermined condition but meets the second predetermined condition, it is determined that the bus voltage of the DC distribution network is too high. At this time, the charging inertia margin is adjusted, and the absorption power of each charging pile is coordinated and controlled according to the charging inertia margin, so that the charging pile with a high charging inertia margin can absorb more electricity during discharge, so that within the adjustable capacity range of the charging pile, the bus voltage of the DC distribution network is reduced to the greatest extent, ensuring that the charging pile has sufficient active support for the bus voltage of the DC distribution network.

[0110] The third determination submodule is used to determine the equivalent SOC coefficient of each charging pile according to the above-mentioned equivalent SOC coefficient and the above-mentioned second predetermined condition when the above-mentioned voltage deviation value does not meet the above-mentioned first predetermined condition and does not meet the above-mentioned second predetermined condition. Determine the above-mentioned discharge inertia margin of the above-mentioned charging pile, wherein, represents the discharge inertia margin of the i-th charging pile.

[0111] Specifically, when the voltage deviation value does not meet the first predetermined condition and does not meet the second predetermined condition, it is determined that the bus voltage of the DC distribution network is low. At this time, the discharge inertia margin is adjusted, and the output power of each charging pile is coordinated and controlled according to the discharge inertia margin, so that the charging pile with a high discharge inertia margin can discharge more electricity during discharge, so that within the adjustable capacity range of the charging pile, the bus voltage of the DC distribution network is maximized, ensuring that the charging pile has sufficient active support for the bus voltage of the DC distribution network.

[0112] The second determination module is used to determine the droop control coefficient of the above-mentioned charging piles according to the above-mentioned actual bus voltage value, the above-mentioned voltage deviation value, the above-mentioned inertia margin of each of the above-mentioned charging piles and the above-mentioned predetermined droop control coefficient.

[0113] In an optional solution, the second determining module is used to:

[0114] The fourth determination submodule is used for determining the voltage deviation value according to the actual bus voltage value, the voltage deviation value, the charging inertia margin of each charging pile, the predetermined droop control coefficient and the Determine the alternative droop control coefficients of the above charging piles respectively, where: represents the alternative droop control coefficient of the i-th charging pile, α is the first predetermined coefficient, β is the second predetermined coefficient, K0 is the predetermined droop control coefficient, represents the charging inertia margin of the i-th charging pile, U dc is the actual bus voltage value mentioned above, ΔU dc is the above voltage deviation value;

[0115] Specifically, when the voltage deviation value does not meet the first predetermined condition but meets the second predetermined condition, it is determined that the bus voltage of the DC distribution network is too high. At this time, the droop control coefficient of each charging pile is determined according to the actual bus voltage value, the voltage deviation value, and the charging inertia margin of each charging pile. The absorption power of each charging pile is coordinated and controlled according to the droop control coefficient, so that the charging pile with a high charging inertia margin can absorb more electricity during discharge, so that the bus voltage of the DC distribution network is minimized within the adjustable capacity range of each charging pile. According to the SOC value status, battery capacity configuration and bus voltage fluctuation of each charging pile, the charging piles are reasonably allocated droop control to ensure that the charging piles have sufficient active support for the bus voltage of the DC distribution network.

[0116] The fifth determination submodule is used for determining the voltage deviation value according to the actual bus voltage value, the voltage deviation value, the discharge inertia margin of each charging pile, the predetermined droop control coefficient and the Determine the above-mentioned alternative droop control coefficients of each of the above-mentioned charging piles respectively, represents the discharge inertia margin of the i-th charging pile;

[0117] Specifically, when the voltage deviation value does not meet the first predetermined condition and does not meet the second predetermined condition, it is determined that the bus voltage of the DC distribution network is low. At this time, the droop control coefficient of each charging pile is determined according to the actual bus voltage value, the voltage deviation value, and the charging inertia margin of each charging pile. The output power of each charging pile is coordinated and controlled according to the droop control coefficient of each charging pile, so that the charging pile with a high discharge inertia margin can discharge more electricity during discharge, so that the bus voltage of the DC distribution network is maximized within the adjustable capacity range of each charging pile. According to the SOC value status, battery capacity configuration and bus voltage fluctuation of each charging pile, the charging piles are reasonably allocated droop control to ensure that the charging piles have sufficient active support for the bus voltage of the DC distribution network.

[0118] The sixth determination submodule is used to determine the above-mentioned alternative droop control coefficient of the above-mentioned charging pile as the above-mentioned droop control coefficient of the above-mentioned charging pile when the above-mentioned alternative droop control coefficient of the above-mentioned charging pile is within the predetermined droop control coefficient range; when the above-mentioned alternative droop control coefficient of the above-mentioned charging pile is less than the minimum value within the predetermined droop control coefficient range, determine the minimum value of the predetermined droop control coefficient range as the above-mentioned droop control coefficient of the above-mentioned charging pile; when the above-mentioned alternative droop control coefficient of the above-mentioned charging pile is greater than the maximum value within the predetermined droop control coefficient range, determine the maximum value of the predetermined droop control coefficient range as the above-mentioned droop control coefficient of the above-mentioned charging pile.

[0119] Specifically, in order to ensure the stable operation of the charging pile, the droop control coefficient of each charging pile needs to be within a predetermined droop control coefficient range.

[0120] In an optional solution, the determining unit includes:

[0121] The third determination module is used to determine the actual bus voltage value, the voltage deviation value and Determine the virtual damping coefficient of each charging pile, where D i is the virtual damping coefficient of the i-th charging pile, D0 is the predetermined virtual damping coefficient, c is the third predetermined coefficient, m1 is the fourth predetermined coefficient, U dc is the actual bus voltage value mentioned above, ΔUdc is the above voltage deviation value;

[0122] Specifically, reasonable damping distribution is performed on the charging piles according to the bus voltage fluctuation of the DC distribution network.

[0123] The fourth determination module is used to determine the actual bus voltage value, the voltage deviation value and Determine the virtual inertia of each of the above charging piles, where C i is the virtual inertia of the i-th charging pile, C0 is the predetermined virtual inertia, k1 is the fifth predetermined coefficient, k2 is the sixth predetermined coefficient, a is the seventh predetermined coefficient, b is the eighth predetermined coefficient, a+b=1, P i is the instantaneous power of the i-th charging pile, P iN is the rated power of the i-th charging pile mentioned above.

[0124] Specifically, the inertia of the charging piles is reasonably distributed according to the bus voltage fluctuation of the DC distribution network.

[0125] The control unit 40 is used to control the operation of each of the above-mentioned charging piles based on the above-mentioned droop control coefficient of each of the above-mentioned charging piles and the above-mentioned inertial damping parameter of each of the above-mentioned charging piles, so as to reduce the difference between the above-mentioned actual bus voltage value and the above-mentioned predetermined bus voltage value.

[0126] Specifically, the present application determines the droop control coefficient value and the inertia damping parameter value of each charging pile according to the SOC value of each charging pile, the battery capacity of each charging pile, the actual bus voltage value and the voltage deviation value, that is, the charging piles are reasonably allocated droop control and inertia damping according to the SOC value status, battery capacity configuration and bus voltage fluctuation of the DC distribution network of each charging pile, so as to reasonably coordinate the active support of the bus voltage of the DC distribution network by each charging pile, so as to ensure sufficient active support for the bus voltage of the DC distribution network.

[0127] In an optional solution, the inertial damping parameter value includes: a virtual damping coefficient value and a virtual inertia value, and the control unit includes:

[0128] The fifth determination module is used to determine the voltage deviation value, the droop control coefficient of each charging pile and The current command value of each of the above charging piles is determined respectively, wherein: is the current command value of the i-th charging pile, is the droop control coefficient of the i-th charging pile, ΔU dc is the above voltage deviation value;

[0129] A control module is used to control the operation of each of the above-mentioned charging piles based on the above-mentioned current command value of each of the above-mentioned charging piles, the above-mentioned virtual damping coefficient of each of the above-mentioned charging piles, and the above-mentioned virtual inertia of each of the above-mentioned charging piles.

[0130] Specifically, Figure 3 As shown, the control logic of the charging pile in the prior art includes: a virtual synchronous machine unit, a voltage PI controller, a current PI controller and a pulse generating unit, wherein the control logic of the virtual synchronous machine unit is: in, is the voltage command value, I i is the instantaneous current of the i-th charging pile, similar to the input of the virtual synchronous machine unit: ,I i , D i , C i and U dc , the output is ,Will Input is sequentially input into the voltage PI controller, the current PI controller and the pulse generating unit to obtain the PWM control signal of the i-th charging pile, so as to realize reasonable droop control distribution and inertia damping distribution of the charging pile according to the SOC value state, battery capacity configuration and bus voltage fluctuation of each charging pile, so as to reasonably coordinate the active support of the bus voltage of the DC distribution network by each charging pile, so as to ensure sufficient active support for the bus voltage of the DC distribution network, wherein the voltage PI controller, the current PI controller and the pulse generating unit are all existing technologies and therefore will not be elaborated here.

[0131] Through the above embodiments, first, during the operation of the charging pile, the SOC value of each charging pile is obtained, and then, when the SOC value of at least one charging pile is within the corresponding SOC value threshold range, the actual bus voltage value and the voltage deviation value are obtained. After that, according to the SOC value of each charging pile, the battery capacity of each charging pile, the actual bus voltage value and the voltage deviation value, the droop control coefficient value of each charging pile and the inertia damping parameter value of each charging pile are respectively determined. Finally, based on the droop control coefficient value of each charging pile and the inertia damping parameter value of each charging pile, the operation of each charging pile is respectively controlled to reduce the difference between the actual bus voltage value and the predetermined bus voltage value. The present application only considers the charging piles whose SOC values ​​are within the corresponding SOC value threshold range to participate in the coordinated control to avoid overcharging and over-discharging of the charging piles, thereby solving the problem that the coordinated control method of connecting charging piles to the DC distribution network in the prior art easily causes overcharging and over-discharging of the charging piles connected to the DC distribution network.

[0132] The coordinated control device for connecting the charging pile to the DC distribution network includes a processor and a memory. The first acquisition unit, the second acquisition unit, the determination unit and the control unit are stored in the memory as program units, and the processor executes the program units stored in the memory to implement corresponding functions. The modules are all located in the same processor; or, the modules are located in different processors in any combination.

[0133] The processor includes a kernel, which retrieves the corresponding program unit from the memory. One or more kernels can be set, and the kernel parameters are adjusted to solve the problem that the coordinated control method of connecting charging piles to the DC distribution network in the prior art easily causes overcharging and over-discharging of the charging piles connected to the DC distribution network.

[0134] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0135] An embodiment of the present invention provides a computer-readable storage medium, which includes a stored program, wherein when the program is running, the device where the computer-readable storage medium is located is controlled to execute the coordinated control method for connecting the charging pile to a DC distribution network.

[0136] Specifically, the coordinated control method for connecting charging piles to a DC distribution network includes:

[0137] Step S201, during the operation of the charging piles, obtaining the SOC value of each of the charging piles;

[0138] Step S202, when the SOC value of at least one of the above charging piles is within the corresponding SOC value threshold range, obtaining the actual bus voltage value and the voltage deviation value;

[0139] Wherein, the actual bus voltage value is the voltage value of the bus of the DC distribution network, the voltage deviation value is the difference between the actual bus voltage value and the predetermined bus voltage value, one of the charging piles has an SOC value threshold range, when the SOC value of the charging pile is less than the minimum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an over-discharge state, when the SOC value of the charging pile is greater than the maximum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an over-charge state, the over-discharge state indicates that the battery capacity of the charging pile is lower than the minimum value of the battery capacity of the charging pile, and the over-charge state indicates that the battery capacity of the charging pile is higher than the maximum value of the battery capacity of the charging pile;

[0140] Step S203, determining the droop control coefficient of each of the above-mentioned charging piles and the inertial damping parameter of each of the above-mentioned charging piles according to the SOC value of each of the above-mentioned charging piles, the maximum value of the battery capacity of each of the above-mentioned charging piles, the above-mentioned actual bus voltage value and the above-mentioned voltage deviation value;

[0141] Step S204, based on the droop control coefficient of each of the above-mentioned charging piles and the inertial damping parameter of each of the above-mentioned charging piles, respectively control the operation of each of the above-mentioned charging piles to reduce the difference between the above-mentioned actual bus voltage value and the above-mentioned predetermined bus voltage value.

[0142] An embodiment of the present invention provides a processor, and the processor is used to run a program, wherein when the program is run, the coordinated control method for connecting the charging pile to a DC distribution network is executed.

[0143] Specifically, the coordinated control method for connecting charging piles to a DC distribution network includes:

[0144] Step S201, during the operation of the charging piles, obtaining the SOC value of each of the charging piles;

[0145] Step S202, when the SOC value of at least one of the above charging piles is within the corresponding SOC value threshold range, obtaining the actual bus voltage value and the voltage deviation value;

[0146] Wherein, the actual bus voltage value is the voltage value of the bus of the DC distribution network, the voltage deviation value is the difference between the actual bus voltage value and the predetermined bus voltage value, one of the charging piles has an SOC value threshold range, when the SOC value of the charging pile is less than the minimum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an over-discharge state, when the SOC value of the charging pile is greater than the maximum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an over-charge state, the over-discharge state indicates that the battery capacity of the charging pile is lower than the minimum value of the battery capacity of the charging pile, and the over-charge state indicates that the battery capacity of the charging pile is higher than the maximum value of the battery capacity of the charging pile;

[0147] Step S203, determining the droop control coefficient of each of the above-mentioned charging piles and the inertial damping parameter of each of the above-mentioned charging piles according to the SOC value of each of the above-mentioned charging piles, the maximum value of the battery capacity of each of the above-mentioned charging piles, the above-mentioned actual bus voltage value and the above-mentioned voltage deviation value;

[0148] Step S204, based on the droop control coefficient of each of the above-mentioned charging piles and the inertial damping parameter of each of the above-mentioned charging piles, respectively control the operation of each of the above-mentioned charging piles to reduce the difference between the above-mentioned actual bus voltage value and the above-mentioned predetermined bus voltage value.

[0149] The present application also provides a computer program product, which, when executed on a data processing device, is suitable for executing a program for initializing at least the following method steps:

[0150] Step S201, during the operation of the charging piles, obtaining the SOC value of each of the charging piles;

[0151] Step S202, when the SOC value of at least one of the above charging piles is within the corresponding SOC value threshold range, obtaining the actual bus voltage value and the voltage deviation value;

[0152] Wherein, the actual bus voltage value is the voltage value of the bus of the DC distribution network, the voltage deviation value is the difference between the actual bus voltage value and the predetermined bus voltage value, one of the charging piles has an SOC value threshold range, when the SOC value of the charging pile is less than the minimum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an over-discharge state, when the SOC value of the charging pile is greater than the maximum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an over-charge state, the over-discharge state indicates that the battery capacity of the charging pile is lower than the minimum value of the battery capacity of the charging pile, and the over-charge state indicates that the battery capacity of the charging pile is higher than the maximum value of the battery capacity of the charging pile;

[0153] Step S203, determining the droop control coefficient of each of the above-mentioned charging piles and the inertial damping parameter of each of the above-mentioned charging piles according to the SOC value of each of the above-mentioned charging piles, the maximum value of the battery capacity of each of the above-mentioned charging piles, the above-mentioned actual bus voltage value and the above-mentioned voltage deviation value;

[0154] Step S204, based on the droop control coefficient of each of the above-mentioned charging piles and the inertial damping parameter of each of the above-mentioned charging piles, respectively control the operation of each of the above-mentioned charging piles to reduce the difference between the above-mentioned actual bus voltage value and the above-mentioned predetermined bus voltage value.

[0155] Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general computing device, they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, and in some cases, the steps shown or described can be executed in a different order than here, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. Thus, the present invention is not limited to any specific combination of hardware and software.

[0156] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0157] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0158] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0159] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0160] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0161] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0162] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0163] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0164] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0165] 1) In the coordinated control method for connecting charging piles to a DC distribution network of the present application, first, during the operation of the charging piles, the SOC value of each charging pile is obtained. Then, when the SOC value of at least one charging pile is within the corresponding SOC value threshold range, the actual bus voltage value and the voltage deviation value are obtained. After that, the droop control coefficient value of each charging pile and the inertia damping parameter value of each charging pile are determined respectively according to the SOC value of each charging pile, the battery capacity of each charging pile, the actual bus voltage value and the voltage deviation value. Finally, based on the droop control coefficient value of each charging pile and the inertia damping parameter value of each charging pile, the operation of each charging pile is controlled respectively to reduce the difference between the actual bus voltage value and the predetermined bus voltage value. The present application only considers the charging piles whose SOC values ​​are within the corresponding SOC value threshold range to participate in the coordinated control to avoid overcharging and over-discharging of the charging piles, thereby solving the problem that the coordinated control method for connecting charging piles to a DC distribution network in the prior art easily causes overcharging and over-discharging of the charging piles connected to the DC distribution network.

[0166] 2) In the coordinated control device for connecting charging piles to a DC distribution network of the present application, first, during the operation of the charging piles, the SOC value of each charging pile is obtained. Then, when the SOC value of at least one charging pile is within the corresponding SOC value threshold range, the actual bus voltage value and the voltage deviation value are obtained. After that, the droop control coefficient value of each charging pile and the inertia damping parameter value of each charging pile are determined respectively according to the SOC value of each charging pile, the battery capacity of each charging pile, the actual bus voltage value and the voltage deviation value. Finally, based on the droop control coefficient value of each charging pile and the inertia damping parameter value of each charging pile, the operation of each charging pile is controlled respectively to reduce the difference between the actual bus voltage value and the predetermined bus voltage value. The present application only considers the charging piles whose SOC values ​​are within the corresponding SOC value threshold range to participate in the coordinated control to avoid overcharging and over-discharging of the charging piles, thereby solving the problem that the coordinated control method for connecting charging piles to a DC distribution network in the prior art easily causes overcharging and over-discharging of the charging piles connected to the DC distribution network.

[0167] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A coordinated control method for connecting a charging pile to a DC distribution network, characterized in that: A plurality of charging piles are electrically connected to a busbar of a DC distribution network, and the method comprises: During the operation of the charging pile, obtaining the SOC value of each charging pile; In the case where the SOC value of at least one of the charging piles is within the corresponding SOC value threshold range, an actual bus voltage value and a voltage deviation value are obtained, wherein the actual bus voltage value is the voltage value of the bus of the DC distribution network, and the voltage deviation value is the difference between the actual bus voltage value and the predetermined bus voltage value. One of the charging piles has an SOC value threshold range. In the case where the SOC value of the charging pile is less than the minimum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an over-discharge state. In the case where the SOC value of the charging pile is greater than the maximum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an over-charge state. The over-discharge state indicates that the battery capacity of the charging pile is lower than the minimum value of the battery capacity of the charging pile, and the over-charge state indicates that the battery capacity of the charging pile is higher than the maximum value of the battery capacity of the charging pile. According to the SOC value of each charging pile, the maximum value of the battery capacity of each charging pile, the actual bus voltage value and the voltage deviation value, respectively determine the droop control coefficient of each charging pile and the inertial damping parameter of each charging pile; Based on the droop control coefficient of each charging pile and the inertial damping parameter of each charging pile, the operation of each charging pile is controlled respectively to reduce the difference between the actual bus voltage value and the predetermined bus voltage value.

2. The method according to claim 1, characterized in that The inertial damping parameters include: a virtual damping coefficient and a virtual inertia. Based on the droop control coefficient of each charging pile and the inertial damping parameters of each charging pile, the operation of each charging pile is controlled respectively, including: According to the voltage deviation value, the droop control coefficient of each charging pile and The current command value of each charging pile is determined respectively, wherein: is the current command value of the i-th charging pile, is the droop control coefficient of the i-th charging pile, ΔU dc is the voltage deviation value; Based on the current command value of each charging pile, the virtual damping coefficient of each charging pile, and the virtual inertia of each charging pile, the operation of each charging pile is controlled respectively.

3. The method according to claim 1 or 2, characterized in that: In the process of respectively determining the droop control coefficient of each charging pile and the inertial damping parameter of each charging pile according to the SOC value of each charging pile, the maximum value of the battery capacity of each charging pile, the actual bus voltage value and the voltage deviation value, the method further includes: When the voltage deviation value satisfies a first predetermined condition, a predetermined droop control coefficient is determined as the droop control coefficient of the charging pile, wherein the first predetermined condition is |ΔU dc |≤0.02U dcref , ΔU dc is the voltage deviation value, U dcref is the predetermined bus voltage value; In the case where the voltage deviation value does not meet the first predetermined condition, the inertia margin of each charging pile is determined according to the SOC value of each charging pile and the maximum value of the battery capacity of each charging pile, wherein the inertia margin is a charging inertia margin or a discharging inertia margin, the charging inertia margin indicates the adjustable degree of the absorbed power of the charging pile, and the discharging inertia margin indicates the adjustable degree of the output power of the charging pile; The droop control coefficients of the charging piles are determined respectively according to the actual bus voltage value, the voltage deviation value, the inertia margin of each charging pile and the predetermined droop control coefficient.

4. The method according to claim 3, characterized in that When the voltage deviation value does not satisfy the first predetermined condition, the inertia margin of each charging pile is determined according to the SOC value of each charging pile and the maximum value of the battery capacity of each charging pile, including: According to the SOC value of each charging pile, the maximum value of the battery capacity of each charging pile and Determine the equivalent SOC coefficient of each charging pile, where: is the equivalent SOC coefficient of the ith charging pile, SOC i is the SOC value of the i-th charging pile, is the maximum value of the battery capacity of the i-th charging pile, and n is the total number of the charging piles connected to the DC distribution network; When the voltage deviation value does not satisfy the first predetermined condition but satisfies the second predetermined condition, according to the equivalent SOC coefficient and Determine the charging inertia margin of each charging pile, where k socmin represents the minimum equivalent SOC coefficient, k socmax is the maximum equivalent SOC coefficient, represents the charging inertia margin of the i-th charging pile, and the second predetermined condition is ΔU dc >0; When the voltage deviation value does not satisfy the first predetermined condition and does not satisfy the second predetermined condition, according to the equivalent SOC coefficient and Determine the discharge inertia margin of each charging pile, wherein: represents the discharge inertia margin of the i-th charging pile.

5. The method according to claim 4, characterized in that Determining the droop control coefficient of each charging pile according to the actual bus voltage value, the voltage deviation value, the inertia margin of each charging pile and the predetermined droop control coefficient, respectively, includes: When the voltage deviation value does not satisfy the first predetermined condition but satisfies the second predetermined condition, the actual bus voltage value, the voltage deviation value, the charging inertia margin of each charging pile, the predetermined droop control coefficient and Determine the alternative droop control coefficient of each charging pile respectively, where: represents the alternative droop control coefficient of the i-th charging pile, α is the first predetermined coefficient, β is the second predetermined coefficient, K0 is the predetermined droop control coefficient, represents the charging inertia margin of the i-th charging pile, U dc is the actual bus voltage value, ΔU dc is the voltage deviation value; When the voltage deviation value does not satisfy the first predetermined condition and does not satisfy the second predetermined condition, the voltage deviation value is adjusted according to the actual bus voltage value, the voltage deviation value, the discharge inertia margin of each charging pile, the predetermined droop control coefficient and respectively determining the alternative droop control coefficient for each of the charging piles, represents the discharge inertia margin of the i-th charging pile; When the alternative droop control coefficient of the charging pile is within a predetermined droop control coefficient range, the alternative droop control coefficient of the charging pile is determined to be the droop control coefficient of the charging pile; when the alternative droop control coefficient of the charging pile is less than the minimum value within the predetermined droop control coefficient range, the minimum value of the predetermined droop control coefficient range is determined to be the droop control coefficient of the charging pile; when the alternative droop control coefficient of the charging pile is greater than the maximum value within the predetermined droop control coefficient range, the maximum value of the predetermined droop control coefficient range is determined to be the droop control coefficient of the charging pile.

6. The method according to claim 2, characterized in that In the process of respectively determining the droop control coefficient of each charging pile and the inertial damping parameter of each charging pile according to the SOC value of each charging pile, the maximum value of the battery capacity of each charging pile, the actual bus voltage value and the voltage deviation value, the method comprises: According to the actual bus voltage value, the voltage deviation value and Determine the virtual damping coefficient of each charging pile, where D i is the virtual damping coefficient of the i-th charging pile, D0 is the predetermined virtual damping coefficient, c is the third predetermined coefficient, m1 is the fourth predetermined coefficient, U dc is the actual bus voltage value, ΔU dc is the voltage deviation value; According to the actual bus voltage value, the voltage deviation value and Determine the virtual inertia of each charging pile, where C i is the virtual inertia of the i-th charging pile, C0 is the predetermined virtual inertia, k1 is the fifth predetermined coefficient, k2 is the sixth predetermined coefficient, a is the seventh predetermined coefficient, b is the eighth predetermined coefficient, a+b=1, P i is the instantaneous power of the i-th charging pile, P iN is the rated power of the i-th charging pile.

7. The method according to claim 1, characterized in that Obtaining the SOC value of each charging pile includes: according to Determine the SOC value of each charging pile, is the initial SOC value of the i-th charging pile, is the instantaneous current of the i-th charging pile, t represents the current moment, and the initial SOC value is the SOC value of the charging pile before operation.

8. A coordination control device for connecting a charging pile to a DC distribution network, characterized in that: A plurality of charging piles are electrically connected to a busbar of a DC distribution network, and the device comprises: A first acquisition unit, configured to acquire an SOC value of each of the charging piles during operation of the charging piles; a second acquisition unit, configured to acquire an actual bus voltage value and a voltage deviation value when the SOC value of at least one of the charging piles is within a corresponding SOC value threshold range, wherein the actual bus voltage value is the voltage value of the bus of the DC distribution network, and the voltage deviation value is the difference between the actual bus voltage value and a predetermined bus voltage value. One of the charging piles has an SOC value threshold range. When the SOC value of the charging pile is less than the minimum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an over-discharge state. When the SOC value of the charging pile is greater than the maximum value of the corresponding SOC value threshold range, it indicates that the charging pile is in an over-charge state. The over-discharge state indicates that the battery capacity of the charging pile is lower than the minimum value of the battery capacity of the charging pile, and the over-charge state indicates that the battery capacity of the charging pile is higher than the maximum value of the battery capacity of the charging pile. A determination unit, configured to determine a droop control coefficient of each charging pile and an inertial damping parameter of each charging pile according to the SOC value of each charging pile, the maximum value of the battery capacity of each charging pile, the actual bus voltage value, and the voltage deviation value; A control unit is used to control the operation of each charging pile based on the droop control coefficient of each charging pile and the inertial damping parameter of each charging pile to reduce the difference between the actual bus voltage value and the predetermined bus voltage value.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute the coordinated control method for connecting a charging pile to a DC distribution network as claimed in any one of claims 1 to 8.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the coordinated control method for connecting a charging pile to a DC distribution network as described in any one of claims 1 to 8 is implemented.

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