Transient voltage drop distribution method, device and equipment for alternating current interconnection networking among multiple direct current microgrids and readable storage medium

Abstract

The invention relates to a transient voltage drop distribution method and device for a multi-direct-current micro-grid alternating-current interconnection network, power equipment, a computer readable storage medium and a computer program product. The method comprises the following steps: if an alternating current load fluctuation exists in a power system, determining an instantaneous voltage drop adjustment coefficient initial value and an instantaneous voltage drop adjustment coefficient variation corresponding to each direct current micro-grid; according to the instantaneous voltage drop adjustment coefficient initial value and the instantaneous voltage drop adjustment coefficient variable quantity, determining an instantaneous voltage drop adjustment coefficient target value corresponding to each DC microgrid; determining a corresponding transient voltage drop change rate according to the instantaneous voltage drop adjustment coefficient target value; the product of the instantaneous voltage drop adjustment coefficient target value corresponding to each DC microgrid and the corresponding transient voltage drop change rate is equal; and according to the transient voltage drop change rate, adjusting transient voltage drop distribution between the direct current buses in each direct current micro-grid. According to the method, the transient voltage drop between the direct-current micro-grids can be balanced to share the influence of alternating-current load fluctuation, and the operation stability of the system is improved.

Description

Technical Field

[0001] The present application relates to the field of electric power technology, and in particular to a method, device, electric power equipment, computer-readable storage medium and computer program product for distributing transient voltage drops in an AC interconnected network between multiple DC microgrids. Background Art

[0002] Microgrids are divided into AC microgrids, DC microgrids, and AC / DC hybrid microgrids. For multiple DC microgrids, multiple machines can be networked to integrate various distributed power sources of multiple DC microgrids to build a larger AC grid. However, the stability of multiple DC microgrids during operation is poor. Summary of the invention

[0003] Based on this, it is necessary to provide a method, device, power equipment, computer-readable storage medium and computer program product for distributing transient voltage drop in AC interconnected networking among multiple DC microgrids to address the above-mentioned technical problems, so as to improve the stability of the networking of multiple DC microgrids.

[0004] In a first aspect, the present application provides a method for allocating transient voltage drop in an AC interconnected network between multiple DC microgrids, which is applied to a power system, wherein the power system includes multiple DC microgrids, and the multiple DC microgrids are interconnected in an AC network; the method includes:

[0005] When there is AC load fluctuation in the power system, determine the initial value of the transient voltage drop regulation coefficient and the change of the transient voltage drop regulation coefficient corresponding to each DC microgrid;

[0006] According to the initial value of the transient voltage drop regulation coefficient and the change of the transient voltage drop regulation coefficient, the target value of the transient voltage drop regulation coefficient corresponding to each DC microgrid is determined;

[0007] According to the target value of the transient voltage drop regulation coefficient, the corresponding transient voltage drop change rate is determined; wherein the product of the target value of the transient voltage drop regulation coefficient corresponding to each DC microgrid and the corresponding transient voltage drop change rate is equal;

[0008] According to the transient voltage drop change rate, the transient voltage drop distribution between DC buses in each DC microgrid is adjusted to share the AC load fluctuation.

[0009] In one embodiment, determining the initial value of the transient voltage drop adjustment coefficient corresponding to each DC microgrid includes:

[0010] Determine the initial change rate of transient voltage drop corresponding to each DC microgrid;

[0011] According to the equivalent total output resistance and initial change rate of transient voltage drop corresponding to each DC microgrid, the initial value of transient voltage drop adjustment coefficient corresponding to each DC microgrid is determined; wherein,

[0012] The product of the initial value of the transient voltage drop regulation coefficient corresponding to each DC microgrid and the corresponding initial transient voltage drop change rate is equal.

[0013] In one embodiment, the method further includes: determining whether the initial value of the transient voltage drop adjustment coefficient corresponding to each DC microgrid meets a preset condition; the preset condition includes the following inequality:

[0014] ,in,

[0015] R i is the equivalent total output resistance;

[0016] J 0i is the frequency time constant of the ith DC microgrid; ω 0 is the rated angular frequency;

[0017] D pi is the damping coefficient of the ith DC microgrid, U o is the output phase voltage, U g is the voltage amplitude;

[0018] X vi is the transient voltage drop regulation coefficient of the i-th DC microgrid;

[0019] Determine the target value of transient voltage drop adjustment coefficient corresponding to each DC microgrid, including:

[0020] When the initial value of the transient voltage drop regulation coefficient corresponding to each DC microgrid meets the preset conditions, the corresponding target value of the transient voltage drop regulation coefficient is determined.

[0021] In one embodiment, determining the change in transient voltage drop adjustment coefficient includes:

[0022] Obtain power information of each DC microgrid; the power information includes maximum instantaneous power, synchronous power factor, output phase voltage and voltage amplitude;

[0023] Based on the power information, the change in the transient voltage drop regulation coefficient is determined; wherein the change in the transient voltage drop regulation coefficient is proportional to the synchronous power coefficient, and the change in the transient voltage drop regulation coefficient is inversely proportional to the output phase voltage, voltage amplitude and maximum instantaneous power.

[0024] In one embodiment, the transient voltage drop adjustment coefficient change is determined according to the following calculation formula:

[0025] ,in,

[0026] Indicates the change in transient voltage drop regulation coefficient;

[0027] S *Indicates the maximum instantaneous power;

[0028] s is the Laplace operator; n represents the number of DC microgrids;

[0029] K s is the synchronous power factor; U o is the output phase voltage; U g is the voltage amplitude;

[0030] Indicates the initial value of the transient voltage drop regulation coefficient.

[0031] In one embodiment, the power system further includes an inverter corresponding to each DC microgrid; a DC bus in the DC microgrid is connected to an AC load via the inverter;

[0032] According to the transient voltage drop change rate, the transient voltage drop distribution between DC buses in each DC microgrid is adjusted, including:

[0033] Generate a corresponding high-frequency switching signal according to the transient voltage drop change rate;

[0034] The inverter is controlled based on high-frequency switching signals to adjust the transient voltage drop distribution between DC buses in each DC microgrid.

[0035] In a second aspect, the present application also provides a transient voltage drop distribution device for AC interconnection between multiple DC microgrids, which is applied to a power system, wherein the power system includes multiple DC microgrids, and the multiple DC microgrids are AC interconnected to form a network; the device includes:

[0036] The first determination module is used to determine the initial value of the transient voltage drop regulation coefficient and the change of the transient voltage drop regulation coefficient corresponding to each DC microgrid when there is AC load fluctuation in the power system; determine the target value of the transient voltage drop regulation coefficient corresponding to each DC microgrid according to the initial value of the transient voltage drop regulation coefficient and the change of the transient voltage drop regulation coefficient;

[0037] The second determination module is used to determine the corresponding transient voltage drop change rate according to the transient voltage drop adjustment coefficient target value; wherein the product of the transient voltage drop adjustment coefficient target value corresponding to each DC microgrid and the corresponding transient voltage drop change rate is equal;

[0038] The distribution module is used to adjust the transient voltage drop distribution between DC buses in each DC microgrid according to the transient voltage drop change rate to share the AC load fluctuation.

[0039] In a third aspect, the present application further provides an electric power device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0040] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0041] In a fifth aspect, the present application further provides a computer program product, including a computer program, which implements the following steps when executed by a processor:

[0042] The above-mentioned transient voltage drop distribution method, device, power equipment, computer-readable storage medium and computer program product for AC interconnected networking between multiple DC microgrids, for a power system connected by multiple DC microgrids, when there is AC load fluctuation, by determining the initial value of the transient voltage drop adjustment coefficient and the change in the transient voltage drop adjustment coefficient corresponding to each DC microgrid, a target value of the transient voltage drop adjustment coefficient can be obtained; since the product of the target value of the transient voltage drop adjustment coefficient corresponding to each DC microgrid and the corresponding transient voltage drop change rate is equal, the corresponding transient voltage drop change rate can be determined after determining the target value of the transient voltage drop adjustment coefficient, thereby achieving transient voltage drop balance between each DC microgrid, accurately and reasonably distributing the transient voltage drop corresponding to each DC microgrid to share the impact of AC load fluctuation, and thereby improving the stability of the AC interconnected networking of multiple DC microgrids during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 It is a flow chart of a transient voltage drop distribution method for AC interconnected networking among multiple DC microgrids in one embodiment;

[0045] Figure 2 A schematic diagram of a DC microgrid architecture for AC interconnection between multiple DC microgrids in one embodiment;

[0046] Figure 3 A first schematic block diagram of a transient voltage drop distribution method for an AC interconnected network of multiple DC microgrids in one embodiment;

[0047] Figure 4 A second schematic block diagram of a transient voltage drop distribution method for an AC interconnected network of multiple DC microgrids in one embodiment;

[0048] Figure 5 It is a structural block diagram of a transient voltage drop distribution device for AC interconnection networking among multiple DC microgrids in one embodiment;

[0049] Figure 6 FIG. 4 is a diagram showing the internal structure of an electric power device in one embodiment. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. The multiple references herein, unless otherwise specified, may be understood to mean two or more than two.

[0051] Distributed Generation (DG) is an important way to effectively utilize abundant clean and renewable energy in various places. It mainly relies on renewable energy such as solar energy, wind energy, biomass energy, and easily available fossil energy such as natural gas to provide electricity for local loads. Compared with the upgrading and transformation of traditional power grids, distributed generation technology has lower costs. With the maturity of technology and the emphasis of various countries on sustainable development, investment has continued to increase, promoting the rapid development of this field. However, the capacity of distributed power sources is small and scattered, and the energy supply is volatile. Direct access to the large power grid may affect its stability. For this reason, the concept of microgrid is proposed, which is divided into AC microgrid, DC microgrid and AC / DC hybrid microgrid. DC microgrid is particularly suitable for DC or non-industrial frequency power sources such as battery energy storage, wind turbines, photovoltaics, and DC loads such as electric vehicles and LED lights due to its simple control.

[0052] The DC microgrid connects multiple sources and loads through a common DC bus. It has a simpler control structure and lower power transmission losses, and is particularly suitable for the integration of multiple distributed energy sources and short-distance power supply scenarios. Each DC microgrid can establish a stable voltage and frequency through a DC-AC inverter to supply power to AC loads off the grid. For multiple DC microgrids, the AC output ports of their inverters can be connected to each other to form a multi-machine network, and various distributed power sources of multiple DC microgrids can be integrated to build a larger capacity AC power grid to provide more stable power supply to off-grid loads.

[0053] However, under the condition of AC interconnection between multiple DC microgrids, the fluctuation of AC load will be distributed differently in different DC microgrids, resulting in uneven distribution of transient changes in DC bus voltage of each DC microgrid, leading to overall operation control disorder, that is, poor stability during operation.

[0054] Based on the above analysis, the present application provides a multi-DC microgrid networking method, in which each DC microgrid corresponds to a transient voltage drop adjustment coefficient and a corresponding transient voltage drop change rate, and the product of the transient voltage drop adjustment coefficient and the transient voltage drop change rate corresponding to each DC microgrid is equal, thereby constructing an identity between each DC microgrid, and when the transient voltage drop adjustment coefficient is determined, the corresponding transient voltage drop change rate can be obtained, thereby more accurately and reasonably determining the suspended voltage drop distribution between each DC microgrid to cope with the impact of AC load fluctuations and avoid overall operation control disorders. The method is described below in the form of multiple embodiments:

[0055] In one embodiment, Figure 1 As shown, a transient voltage drop distribution method for AC interconnection between multiple DC microgrids is provided, which is applied to a power system, wherein the power system includes multiple DC microgrids, and the multiple DC microgrids are interconnected by AC; the method includes steps S101 to S103:

[0056] Step S101: when there is AC load fluctuation in the power system, determine the initial value of the transient voltage drop regulation coefficient and the change amount of the transient voltage drop regulation coefficient corresponding to each DC microgrid.

[0057] The power system may be a power system formed by interconnecting multiple DC microgrids to form an AC network, and accordingly, it can supply power to AC loads. In the actual power supply process, the AC load may change, that is, the AC load fluctuates.

[0058] Exemplarily, each DC microgrid may correspond to an initial value of a transient voltage drop regulation coefficient and a change in the transient voltage drop regulation coefficient; the initial values ​​of the transient voltage drop regulation coefficients between the DC microgrids may be the same or different; and the changes in the transient voltage drop regulation coefficients between the DC microgrids may be the same or different.

[0059] Exemplarily, due to AC load fluctuations, each DC microgrid in the power system will generate a transient voltage drop accordingly. The transient voltage drop of a DC microgrid may be a rapid drop in the DC bus voltage in a short period of time due to a sudden load change, power failure or other types of disturbances in the DC microgrid system. This may have an adverse effect on the equipment connected to the DC microgrid, especially voltage-sensitive equipment. In view of this, by determining the initial value of the transient voltage drop adjustment coefficient and the change in the transient voltage drop adjustment coefficient corresponding to each DC microgrid, it is convenient to carry out subsequent steps such as the allocation of transient voltage drops, so that each DC microgrid can cope with AC load fluctuations and ensure the stability of power system operation.

[0060] Step S102: determining the target value of the transient voltage drop regulation coefficient corresponding to each DC microgrid according to the initial value of the transient voltage drop regulation coefficient and the change of the transient voltage drop regulation coefficient.

[0061] Exemplarily, the target values ​​of transient voltage drop regulation coefficients between DC microgrids may be the same or different.

[0062] Step S103: determining the corresponding transient voltage drop change rate according to the transient voltage drop adjustment coefficient target value; wherein the product of the transient voltage drop adjustment coefficient target value corresponding to each DC microgrid and the corresponding transient voltage drop change rate is equal.

[0063] Exemplarily, the target value of the transient voltage drop regulation coefficient corresponding to the DC microgrid A1 can be X1, and the corresponding transient voltage drop change rate can be Y1. The target value of the transient voltage drop regulation coefficient corresponding to the DC microgrid A2 can be X2, and the corresponding transient voltage drop change rate can be Y2. Then, the product of X1 and Y1 is equal to the product of X2 and Y2.

[0064] Step S104: adjusting the transient voltage drop distribution between DC buses in each DC microgrid according to the transient voltage drop change rate to share the AC load fluctuation.

[0065] For example, after determining the transient voltage drop change rate corresponding to each DC microgrid, the transient voltage drop can be distributed and the impact load can be shared among the DC microgrids accordingly.

[0066] In this embodiment, for a power system formed by AC interconnection of multiple DC microgrids, when there is AC load fluctuation, the target value of the transient voltage drop adjustment coefficient can be obtained by determining the initial value of the transient voltage drop adjustment coefficient corresponding to each DC microgrid and the change in the transient voltage drop adjustment coefficient; since the product of the target value of the transient voltage drop adjustment coefficient corresponding to each DC microgrid and the corresponding transient voltage drop change rate is equal, the corresponding transient voltage drop change rate can be determined after determining the target value of the transient voltage drop adjustment coefficient, thereby achieving transient voltage drop balance between each DC microgrid, accurately and reasonably allocating the transient voltage drop corresponding to each DC microgrid to share the impact of AC load fluctuation, and thereby improving the stability of the AC interconnection of multiple DC microgrids during operation.

[0067] In one of the embodiments, determining the initial value of the transient voltage drop regulation coefficient corresponding to each DC microgrid in the above embodiment may include: determining the initial change rate of the transient voltage drop corresponding to each DC microgrid; determining the initial value of the transient voltage drop regulation coefficient corresponding to each DC microgrid according to the equivalent total output resistance and the initial change rate of the transient voltage drop corresponding to each DC microgrid; wherein the product of the initial value of the transient voltage drop regulation coefficient corresponding to each DC microgrid and the corresponding initial change rate of the transient voltage drop is equal to.

[0068] The initial value of the transient voltage drop regulation coefficient may be the initial value of the transient voltage drop regulation coefficient when multiple DC microgrids are interconnected with AC.

[0069] Exemplarily, when multiple DC microgrids are initially interconnected, the law that the product of the initial value of the transient voltage drop regulation coefficient corresponding to each DC microgrid and the corresponding initial change rate of the transient voltage drop is equal also applies. Accordingly, the initial value of the transient voltage drop regulation coefficient may correspond to the initial change rate of the transient voltage drop, and the product of the initial change rate of the transient voltage drop corresponding to each DC microgrid and the initial value of the corresponding transient voltage drop regulation coefficient may be equal, hereinafter referred to as the "product equality control law". For example, the initial value of the transient voltage drop regulation coefficient corresponding to the DC microgrid A10 may be X10, and the corresponding initial change rate of the transient voltage drop may be Y10, and the initial value of the transient voltage drop regulation coefficient corresponding to the DC microgrid A20 may be X20, and the corresponding initial change rate of the transient voltage drop may be Y20, then it can be: the product of X10 and Y10 is equal to the product of X20 and Y20.

[0070] Exemplarily, the initial change rate of the transient voltage drop corresponding to each DC microgrid can be determined, and based on the above-mentioned product equality control law, the initial value of the transient voltage drop adjustment coefficient corresponding to each DC microgrid can be determined. At the same time, the initial value of the transient voltage drop adjustment coefficient can also be solved from aspects such as resistance. Exemplarily, whether the initial value of the transient voltage drop adjustment coefficient is correct can be determined and verified based on the equivalent total output resistance corresponding to each DC microgrid.

[0071] In this embodiment, the initial value of the transient voltage drop adjustment coefficient corresponding to each DC microgrid is determined by the initial change rate of the transient voltage drop corresponding to each DC microgrid and the corresponding equivalent total output resistance, and based on the product equality control law, so that the initial value of the transient voltage drop adjustment coefficient obtained is more accurate and suitable for transient voltage drop distribution.

[0072] In one embodiment, the aforementioned method may further include: determining whether the initial value of the transient voltage drop adjustment coefficient corresponding to each DC microgrid meets a preset condition; the preset condition includes the following inequality:

[0073] ,in,

[0074] R i is the equivalent total output resistance;

[0075] J 0i is the frequency time constant of the ith DC microgrid; ω 0 is the rated angular frequency;

[0076] D pi is the damping coefficient of the ith DC microgrid, U o is the output phase voltage, U gis the voltage amplitude;

[0077] X vi is the initial value of the transient voltage drop regulation coefficient of the i-th DC microgrid;

[0078] Determining a target value of a transient voltage drop regulation coefficient corresponding to each DC microgrid includes: determining a corresponding target value of the transient voltage drop regulation coefficient when an initial value of the transient voltage drop regulation coefficient corresponding to each DC microgrid meets a preset condition.

[0079] Exemplarily, when the initial value of the transient voltage drop adjustment coefficient satisfies the inequality, subsequent steps such as determining the target value of the transient voltage drop adjustment coefficient can be performed; otherwise, if it does not satisfy the inequality,

[0080] In this embodiment, preset conditions are set based on actual power parameters such as equivalent total output resistance, damping coefficient, output phase voltage, etc. corresponding to each DC microgrid, and the preset conditions are used to verify the initial value of the transient voltage drop adjustment coefficient determined by the above steps. Specifically, when the initial value of the transient voltage drop adjustment coefficient satisfies the inequality, subsequent steps such as determining the target value of the transient voltage drop adjustment coefficient can be performed. This helps to improve the accuracy of the determined initial value of the transient voltage drop adjustment coefficient, avoids launching subsequent steps based on the error of the initial value of the transient voltage drop adjustment coefficient, and thus helps to ensure the accuracy of the transient voltage drop distribution of each DC microgrid.

[0081] In one of the embodiments, determining the change in the transient voltage drop regulation coefficient in the aforementioned embodiment may include: obtaining power information of each DC microgrid; the power information includes maximum instantaneous power, synchronous power coefficient, output phase voltage and voltage amplitude; based on the power information, determining the change in the transient voltage drop regulation coefficient; wherein the change in the transient voltage drop regulation coefficient is directly proportional to the synchronous power coefficient, and the change in the transient voltage drop regulation coefficient is inversely proportional to the output phase voltage, voltage amplitude and maximum instantaneous power.

[0082] In this embodiment, the power information of each DC microgrid is obtained and the transient voltage drop adjustment coefficient change is determined by using the power information. This enables the determined transient voltage drop adjustment coefficient change to more accurately reflect the actual situation of the corresponding DC microgrid, thereby facilitating a more accurate subsequent transient voltage drop distribution.

[0083] In one embodiment, the change amount of the transient voltage drop adjustment coefficient in the above embodiment can be determined according to the following calculation formula:

[0084] ,in,

[0085] Indicates the change in transient voltage drop regulation coefficient;

[0086] S* Indicates the maximum instantaneous power;

[0087] s is the Laplace operator; n represents the number of DC microgrids;

[0088] K s is the synchronous power factor; U o is the output phase voltage; U g is the voltage amplitude;

[0089] Indicates the initial value of the transient voltage drop regulation coefficient.

[0090] In this embodiment, a specific calculation formula for determining the change in transient voltage drop adjustment coefficient based on power information is provided, which can directly and accurately obtain the change in transient voltage drop adjustment coefficient, thereby facilitating the subsequent more accurate transient voltage drop allocation.

[0091] In one of the embodiments, the power system in the aforementioned embodiment also includes an inverter corresponding to each DC microgrid; the DC bus in the DC microgrid is connected to the AC load through the inverter; in the aforementioned embodiment, adjusting the transient voltage drop distribution between the DC buses in each DC microgrid according to the transient voltage drop change rate may include: generating a corresponding high-frequency switching signal according to the transient voltage drop change rate; controlling the inverter based on the high-frequency switching signal to adjust the transient voltage drop distribution between the DC buses in each DC microgrid.

[0092] In this embodiment, since the DC bus in the DC microgrid is connected to the AC load through an inverter, after determining the transient voltage drop change rate corresponding to each DC microgrid, a corresponding high-frequency switching signal can be generated through the transient voltage drop change rate to control the inverter, thereby adjusting the transient voltage drop distribution between the DC buses in each DC microgrid.

[0093] In an exemplary embodiment, Figure 2 As shown, a possible system architecture of AC interconnection between multiple DC microgrids is provided. Each DC microgrid in the DC microgrid of AC interconnection between multiple DC microgrids is connected to the three-phase AC side of the inverter for parallel networking, and is connected to one side of the three-wire AC bus; the load switch connects the load bus and the three-wire AC bus; the photovoltaic power generation and energy storage device of distributed power generation in the DC microgrid unit are connected to the DC bus through the DC converter, and the wind power generation of distributed power generation in the DC microgrid unit is connected to the DC bus through the rectifier, and the DC bus is connected to the DC and AC loads through the DC converter and the inverter respectively.

[0094] The corresponding transient voltage drop balancing strategy for AC interconnection networking among multiple DC microgrids is to dynamically adjust the transient voltage drop distribution of the DC bus inside each DC microgrid when the AC side load power steps by introducing an instantaneous voltage drop adjustment coefficient module into the AC interconnection networking control method among multiple DC microgrids.

[0095] By introducing the instantaneous voltage drop regulation coefficient into the core control law among the active power setting of each channel, the load power and the transient voltage drop change rate of the DC bus within each DC microgrid of the AC side control method of the multi-DC microgrid inverter, it can be further deduced that: when multiple DC microgrids are AC interconnected to form a network, the transient voltage drop distribution of the shared impact load of each DC microgrid on the DC bus within each DC microgrid is inversely proportional to the instantaneous voltage drop regulation coefficient in each DC microgrid unit.

[0096] The above-mentioned "multiple DC microgrids AC interconnection network control method" is described below. In this method, multiple DC microgrids are interconnected to form an AC network to supply power to the load in the substation area. Specifically:

[0097] First, the output current signal and the capacitor voltage signal are sampled, and the output current sampling signal and the capacitor voltage sampling signal are input into the instantaneous power calculation module, and the instantaneous power calculation module outputs the calculated instantaneous active power signal and instantaneous reactive power signal.

[0098] Then, these signals are transmitted to the network control module, which outputs voltage amplitude and angle signals to the voltage and current closed-loop module. The voltage and current inner loop generates the output voltage dq coordinate axis instructions of the inverter, which are then converted into output voltage instructions of the three-phase coordinate system through coordinate system transformation.

[0099] Finally, the above instructions are input into the PWM generation module to generate a high-frequency switching signal of the inverter. Exemplarily, the inverter may be a high-frequency inverter, which may realize voltage or current modulation by PWM (pulse width modulation).

[0100] like Figure 3 As shown, a possible transient voltage drop distribution method for multiple DC microgrids in AC interconnection is provided, wherein:

[0101] L f and C f The filter inductor and filter capacitor of the output filter of the inverter;

[0102] L g and R g are the line inductance and resistance;

[0103] P and Q represent the active power and reactive power output by the inverter, respectively;

[0104] i 1Indicates the inverter output current;

[0105] i 2 Indicates the output current injected into the load side;

[0106] P ref and Q ref They are active power command and reactive power command respectively;

[0107] u c Outputting a filter capacitor voltage for the inverter;

[0108] U is the voltage amplitude generated by the network control module;

[0109] θ is the voltage angle generated by the network control module;

[0110] C dc is the DC capacitance value between the inverter and the DC microgrid.

[0111] Furthermore, in a power supply network where multiple DC microgrids are interconnected with each other, when the AC load fluctuates or even steps, the transient voltage drop change rate of the DC busbars within each of the multiple DC microgrids and the impact load power of the DC microgrid units are proportional to each other as follows:

[0112]

[0113] Where ∆H i is the transient voltage drop change rate of the DC bus in the i-th DC microgrid unit;

[0114] is the impact load power of the ith DC microgrid unit;

[0115] is the rated value of the DC capacitor voltage between the inverter and the DC microgrid;

[0116] is the instantaneous value of the DC capacitor voltage between the i-th inverter and the DC microgrid;

[0117] C dc is the DC capacitance value between the inverter and the DC microgrid.

[0118] Furthermore, in the control of multiple DC microgrids interconnected with AC, the transient voltage drop change H of the DC bus in the DC microgrid unit i With output The relationship between them is shown in the following matrix:

[0119]

[0120] in, is the phase angle of the voltage vector of the ith DC microgrid unit;

[0121] P outi Output active power for the i-th DC microgrid unit;

[0122] J 0i Here it is defined as the frequency time constant of the ith DC microgrid unit;

[0123] is the rated angular frequency, D pi Here it is defined as the damping coefficient of the ith DC microgrid unit;

[0124] is the rated value of the DC capacitor voltage between the inverter and the DC microgrid;

[0125] C dc is the DC capacitance value between the inverter and the DC microgrid.

[0126] Furthermore, in the multi-DC microgrid control system, the output: ΔP out1 …ΔP outN With input quantity: ΔP load , ΔP set1 …ΔP setN The coupling expression between them is in matrix form as follows:

[0127]

[0128] in, is the output active power change of the i-th DC microgrid unit;

[0129] is the change in rated active power of the i-th DC microgrid unit;

[0130] is the load power variation in the entire multi-DC microgrid system;

[0131] G ip and G iw They represent the transfer functions of active power command to output power and frequency disturbance to output power respectively, and their expressions are as follows:

[0132]

[0133]

[0134] Among them, U o is the output phase voltage, U g is the voltage amplitude at PCC;

[0135] X gi is the grid-side equivalent impedance of the i-th DC microgrid unit.

[0136] J 0i is the frequency time constant of the ith DC microgrid unit, ω 0 is the rated angular frequency;

[0137] D pi is the damping coefficient of the ith DC microgrid unit.

[0138] The following is a more detailed description of the transient voltage drop balancing strategy for AC interconnection between multiple DC microgrids: Figure 3 As shown, a possible multi-DC microgrid AC interconnection networking control method is provided, in which an instantaneous voltage drop adjustment coefficient module is added. When multiple DC microgrids are AC interconnected, the control equation of the instantaneous voltage drop adjustment coefficient module of each DC microgrid unit newly added in the multi-DC microgrid AC interconnection networking control method is as follows:

[0139] ,

[0140] Among them, v d1 and v q1 It is the d-axis and q-axis components of the reference voltage signal output by the AC interconnection network control method corresponding to the No. 1 DC microgrid in the synchronous rotating coordinate system;

[0141] i d1 and i q1 are the d-axis and q-axis components of the output current of the network control module corresponding to the No. 1 DC microgrid in the synchronous rotating coordinate system;

[0142] X v1 is the instantaneous voltage drop adjustment coefficient corresponding to DC microgrid No. 1;

[0143] v d2 and v q2 It is the d-axis and q-axis components of the reference voltage signal output by the network control module corresponding to the No. 2 DC microgrid in the synchronous rotating coordinate system;

[0144] i d2 and i q2 are the d-axis and q-axis components of the output current of the AC interconnection network control method corresponding to the No. 2 DC microgrid in the synchronous rotating coordinate system;

[0145] X v2 is the instantaneous voltage drop adjustment coefficient corresponding to the No. 2 DC microgrid;

[0146] v dn and v qn are the d-axis and q-axis components of the reference voltage signal output by the AC interconnection network control method corresponding to the DC microgrid No. n in the synchronous rotating coordinate system;

[0147] i dn and i qn are the d-axis and q-axis components of the output current of the AC interconnection network control method corresponding to the DC microgrid No. n in the synchronous rotating coordinate system;

[0148] X vn is the instantaneous voltage drop adjustment coefficient corresponding to the device No. n;

[0149] *It represents the output voltage instruction after the interaction between the output reference voltage signal and the instantaneous voltage drop adjustment coefficient of the AC interconnection network control method.

[0150] The core control law mentioned above is explained below. The core control law is the core control law between the active power setting of each channel, the load power and the transient voltage drop change rate of the DC bus inside each DC microgrid in the AC interconnection networking control method of multiple DC microgrids, as shown below:

[0151] ,

[0152] Where ∆H i is the transient voltage drop change rate of the DC bus in the i-th DC microgrid unit;

[0153] W ii represents the control law of the power reference command of the i-th DC microgrid unit on the power output of the i-th DC microgrid unit;

[0154] W ij represents the control law of the power reference command of the jth DC microgrid unit on the power output of the ith DC microgrid unit;

[0155] W iL is the control law of load power on the power output of the i-th DC microgrid unit;

[0156] is the change in rated active power of the i-th DC microgrid unit;

[0157] is the load power variation in the entire multi-DC microgrid system;

[0158] is the rated value of the DC voltage between the inverter and the DC microgrid;

[0159] C dc is the DC capacitance value between the inverter and the DC microgrid.

[0160] The specific expressions in the core control law between the active power setting of each channel, the load power and the output active power of each channel in the above-mentioned multi-DC microgrid AC interconnection control method are as follows:

[0161] ;

[0162] ;

[0163] ;

[0164] ;

[0165] ;

[0166] Among them, K i is the synchronous power coefficient of the i-th DC microgrid unit;

[0167] M i is the intermediate variable of the i-th DC microgrid unit;

[0168] E is the inverter side voltage, V is the grid side voltage;

[0169] X vi is the instantaneous voltage drop regulation coefficient of the i-th DC microgrid unit;

[0170] J 0i is the frequency time constant of the ith DC microgrid unit;

[0171] ω 0 is the rated angular frequency, D pi is the damping coefficient of the ith DC microgrid unit;

[0172] i, j, and k represent the numbers of the DC microgrid units, and n represents the number of DC microgrid units;

[0173] W ii represents the control law of the power reference command of the i-th DC microgrid unit on the power output of the i-th DC microgrid unit;

[0174] W ij represents the control law of the power reference command of the jth DC microgrid unit on the power output of the ith DC microgrid unit;

[0175] W iL is the control law of the load power on the power output of the i-th DC microgrid unit.

[0176] The following is an explanation of the control law of the transient voltage drop distribution of the DC busbars within each DC microgrid and the instantaneous voltage drop adjustment coefficient of each DC microgrid unit when multiple DC microgrids are interconnected to form an AC network. It can correspond to the following equation:

[0177] ,in,

[0178] Indicates the DC bus transient voltage drop change rate of each DC microgrid unit;

[0179] It represents the output power rating of each DC microgrid unit;

[0180] is the load power variation in the entire multi-DC microgrid system;

[0181] W ii represents the control law of the power reference command of the i-th DC microgrid unit on the power output of the i-th DC microgrid unit;

[0182] W ij represents the control law of the power reference command of the jth DC microgrid unit on the power output of the ith DC microgrid unit;

[0183] W iL is the control law of load power on the power output of the i-th DC microgrid unit;

[0184] is the rated value of the DC capacitor voltage between the inverter and the DC microgrid;

[0185] C dc is the DC capacitance value between the inverter and the DC microgrid;

[0186] K s Synchronous power coefficient, s is the Laplace operator.

[0187] According to the above control law, it can be obtained that when multiple DC microgrids are interconnected, the transient voltage drop change rate of the DC bus within each DC microgrid is inversely proportional to the instantaneous voltage drop adjustment coefficient, as shown below:

[0188] ,

[0189] Therefore, the instantaneous voltage drop adjustment coefficient that the DC microgrid unit needs to dynamically adjust when multiple DC microgrids are interconnected can be obtained. The core control law is as follows:

[0190] ,

[0191] Where j represents the number of the DC microgrid unit, n represents the number of DC microgrid units, S * Represents the maximum instantaneous power of each DC microgrid unit, K s Synchronous power factor, U o is the output phase voltage, U g is the voltage amplitude at PCC, Indicates the dynamic adjustment of the instantaneous pressure drop regulation coefficient, Indicates the initial value of the instantaneous voltage drop adjustment coefficient. J 0i is the frequency time constant of the ith DC microgrid unit, ω 0 is the rated angular frequency, D i is the damping coefficient of the ith DC microgrid unit.

[0192] The initial value restriction condition of the instantaneous voltage drop adjustment coefficient based on the stability restriction condition is explained below: When the multiple DC microgrids are AC interconnected, the initial value of the instantaneous voltage drop adjustment coefficient needs to meet the stability restriction condition of each DC microgrid unit, as shown below:

[0193] ,

[0194] Wherein, R is the equivalent total output resistance of each DC microgrid unit.

[0195] At the same time, according to the above control law, the initial value of the instantaneous voltage drop adjustment coefficient also needs to meet the following conditions:

[0196] .

[0197] Through the above-mentioned transient voltage drop balancing strategy of AC interconnected networking among multiple DC microgrids, the transient voltage drop of the DC bus inside each DC microgrid can be balanced and coordinated when the AC load changes, thereby improving the impact resistance of the entire microgrid.

[0198] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0199] Based on the same inventive concept, the embodiment of the present application also provides a transient voltage drop distribution device for multiple DC microgrids AC interconnected networking for implementing the transient voltage drop distribution method for multiple DC microgrids AC interconnected networking involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations of the embodiments of one or more transient voltage drop distribution devices for multiple DC microgrids AC interconnected networking provided below can refer to the limitations of the transient voltage drop distribution method for multiple DC microgrids AC interconnected networking above, and will not be repeated here.

[0200] In an exemplary embodiment, Figure 5 As shown, a transient voltage drop distribution device 500 for AC interconnection between multiple DC microgrids is provided, which is applied to a power system. The power system includes multiple DC microgrids, and the multiple DC microgrids are AC interconnected to form a network; the transient voltage drop distribution device 500 for AC interconnection between multiple DC microgrids includes:

[0201] The first determination module 501 is used to determine the initial value of the transient voltage drop adjustment coefficient and the change of the transient voltage drop adjustment coefficient corresponding to each DC microgrid when there is AC load fluctuation in the power system; determine the target value of the transient voltage drop adjustment coefficient corresponding to each DC microgrid according to the initial value of the transient voltage drop adjustment coefficient and the change of the transient voltage drop adjustment coefficient;

[0202] The second determination module 502 is used to determine the corresponding transient voltage drop change rate according to the transient voltage drop adjustment coefficient target value; wherein the product of the transient voltage drop adjustment coefficient target value corresponding to each DC microgrid and the corresponding transient voltage drop change rate is equal;

[0203] The distribution module 503 is used to adjust the transient voltage drop distribution between DC buses in each DC microgrid according to the transient voltage drop change rate to share the AC load fluctuation.

[0204] In one of the embodiments, the first determination module 501 is also used to determine the initial value of the transient voltage drop adjustment coefficient corresponding to each DC microgrid, including: determining the initial change rate of the transient voltage drop corresponding to each DC microgrid; determining the initial value of the transient voltage drop adjustment coefficient corresponding to each DC microgrid according to the equivalent total output resistance and the initial change rate of the transient voltage drop corresponding to each DC microgrid; wherein the product of the initial value of the transient voltage drop adjustment coefficient corresponding to each DC microgrid and the corresponding initial change rate of the transient voltage drop is equal to.

[0205] In one embodiment, the first determination module 501 is further used to determine whether the initial value of the transient voltage drop adjustment coefficient corresponding to each DC microgrid meets a preset condition; the preset condition includes the following inequality:

[0206] ,in,

[0207] R i is the equivalent total output resistance;

[0208] J 0i is the frequency time constant of the ith DC microgrid; ω 0 is the rated angular frequency;

[0209] D pi is the damping coefficient of the ith DC microgrid, U o is the output phase voltage, U g is the voltage amplitude;

[0210] X vi is the transient voltage drop regulation coefficient of the i-th DC microgrid;

[0211] The first determination module 501 is also used to determine the target value of the transient voltage drop adjustment coefficient corresponding to each DC microgrid, including: when the initial value of the transient voltage drop adjustment coefficient corresponding to each DC microgrid meets the preset conditions, determining the corresponding target value of the transient voltage drop adjustment coefficient.

[0212] In one embodiment, the first determining module 501 is further used to determine the change amount of the transient voltage drop adjustment coefficient, including:

[0213] Obtain power information of each DC microgrid; the power information includes maximum instantaneous power, synchronous power factor, output phase voltage and voltage amplitude;

[0214] Based on the power information, the change in the transient voltage drop regulation coefficient is determined; wherein the change in the transient voltage drop regulation coefficient is proportional to the synchronous power coefficient, and the change in the transient voltage drop regulation coefficient is inversely proportional to the output phase voltage, voltage amplitude and maximum instantaneous power.

[0215] In one embodiment, the first determination module 501 is further used to determine the transient voltage drop adjustment coefficient change according to the following calculation formula:

[0216] ,in,

[0217] Indicates the change in transient voltage drop regulation coefficient;

[0218] S * Indicates the maximum instantaneous power;

[0219] s is the Laplace operator; n represents the number of DC microgrids;

[0220] K s is the synchronous power factor; U o is the output phase voltage; U g is the voltage amplitude;

[0221] Indicates the initial value of the transient voltage drop regulation coefficient.

[0222] In one of the embodiments, the power system also includes an inverter corresponding to each DC microgrid; the DC bus in the DC microgrid is connected to the AC load through the inverter; the distribution module 503 is also used to adjust the transient voltage drop distribution between the DC buses in each DC microgrid according to the transient voltage drop change rate, including: generating a corresponding high-frequency switching signal according to the transient voltage drop change rate; controlling the inverter based on the high-frequency switching signal to adjust the transient voltage drop distribution between the DC buses in each DC microgrid.

[0223] Each module in the above-mentioned transient voltage drop distribution device 500 for interconnecting multiple DC microgrids with AC can be implemented in whole or in part by software, hardware, or a combination thereof. Each of the above-mentioned modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each of the above modules.

[0224] In an exemplary embodiment, there is provided a power system, comprising:

[0225] A plurality of DC microgrids, wherein the DC microgrids are connected to inverters; the plurality of DC microgrids are networked with multiple machines, and supply power to AC loads based on the AC outputs of the plurality of inverters; and,

[0226] Multi-DC microgrid control module, including:

[0227] The instantaneous power calculation module is used to calculate and output the corresponding instantaneous power signal based on the output current sampling signal and capacitor voltage sampling signal of each DC microgrid collected by the power system;

[0228] A network control module is used to receive and determine and output voltage amplitude and angle signals based on the instantaneous power signal;

[0229] The transient voltage drop regulation coefficient module is used to determine the initial value of the transient voltage drop regulation coefficient corresponding to each DC microgrid when there is AC load fluctuation in the power system; based on the initial value of the transient voltage drop regulation coefficient, determine the corresponding target value of the transient voltage drop regulation coefficient;

[0230] The voltage and current closed-loop module is used to receive the voltage amplitude, the angle signal and the target value of the transient voltage drop adjustment coefficient; and determine the corresponding transient voltage drop change rate based on the target value of the transient voltage drop adjustment coefficient; wherein the product of the target value of the transient voltage drop adjustment coefficient corresponding to each DC microgrid and the corresponding transient voltage drop change rate is equal; based on the voltage amplitude, the angle signal and the transient voltage drop change rate, a voltage command is generated and output;

[0231] The pulse width modulation generation module is used to receive and generate a high-frequency switching signal based on a voltage command; and control the inverter based on the high-frequency switching signal to adjust the transient voltage drop distribution between the DC buses in each DC microgrid.

[0232] In an exemplary embodiment, a power device is provided. The power device may be a server, and its internal structure diagram may be as shown in FIG. Figure 6As shown. The power equipment includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the power equipment is used to provide computing and control capabilities. The memory of the power equipment includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the power equipment is used to store relevant data required for realizing the transient voltage drop distribution of the AC interconnected network between multiple DC microgrids, such as voltage amplitude, the number of DC microgrids, output phase voltage, etc. The input / output interface of the power equipment is used to exchange information between the processor and the external device. The communication interface of the power equipment is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a transient voltage drop distribution method for the AC interconnected network of multiple DC microgrids is realized.

[0233] Those skilled in the art will understand that Figure 6 The structure shown in the figure is only a block diagram of a part of the structure related to the scheme of the present application, and does not constitute a limitation on the power equipment to which the scheme of the present application is applied. The specific power equipment may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0234] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0235] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0236] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0237] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0238] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0239] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for allocating transient voltage drop in an AC interconnected network between multiple DC microgrids, characterized in that: Applied to a power system, the power system includes a plurality of DC microgrids, and the plurality of DC microgrids are interconnected to form an AC network; the method includes: In the case where there is AC load fluctuation in the power system, determining an initial value of a transient voltage drop regulation coefficient and a change in the transient voltage drop regulation coefficient corresponding to each of the DC microgrids; Determining a target value of the transient voltage drop regulation coefficient corresponding to each of the DC microgrids according to the initial value of the transient voltage drop regulation coefficient and the change in the transient voltage drop regulation coefficient; According to the transient voltage drop adjustment coefficient target value, the corresponding transient voltage drop change rate is determined; wherein the product of the transient voltage drop adjustment coefficient target value corresponding to each of the DC microgrids and the corresponding transient voltage drop change rate is equal; According to the transient voltage drop change rate, the transient voltage drop distribution between the DC buses in each of the DC microgrids is adjusted to share the AC load fluctuation.

2. The method according to claim 1, characterized in that The determining of the initial value of the transient voltage drop adjustment coefficient corresponding to each of the DC microgrids includes: Determining an initial change rate of transient voltage drop corresponding to each of the DC microgrids; According to the equivalent total output resistance corresponding to each of the DC microgrids and the initial change rate of the transient voltage drop, the initial value of the transient voltage drop adjustment coefficient corresponding to each of the DC microgrids is determined; wherein, The product of the initial value of the transient voltage drop adjustment coefficient corresponding to each of the DC microgrids is equal to the corresponding initial change rate of the transient voltage drop.

3. The method according to claim 2, characterized in that The method further includes: determining whether the initial value of the transient voltage drop adjustment coefficient corresponding to each of the DC microgrids meets a preset condition; the preset condition includes the following inequality: ,in, R i is the equivalent total output resistance; J 0i is the frequency time constant of the ith DC microgrid; ω0 is the rated angular frequency; D pi is the damping coefficient of the ith DC microgrid, U o is the output phase voltage, U g is the voltage amplitude; X vi is the initial value of the transient voltage drop adjustment coefficient of the i-th DC microgrid; The step of determining a target value of a transient voltage drop adjustment coefficient corresponding to each of the DC microgrids comprises: When the initial value of the transient voltage drop regulation coefficient corresponding to each of the DC microgrids meets the preset condition, the corresponding target value of the transient voltage drop regulation coefficient is determined.

4. The method according to claim 1, characterized in that: The determining the change in the transient voltage drop adjustment coefficient includes: Acquire power information of each of the DC microgrids; the power information includes maximum instantaneous power, synchronous power factor, output phase voltage, and voltage amplitude; Based on the power information, the change in the transient voltage drop regulation coefficient is determined; wherein the change in the transient voltage drop regulation coefficient is directly proportional to the synchronous power coefficient, and the change in the transient voltage drop regulation coefficient is inversely proportional to the output phase voltage, the voltage amplitude and the maximum instantaneous power.

5. The method according to claim 4, characterized in that The change in the transient voltage drop adjustment coefficient is determined according to the following calculation formula: ,in, Indicates the change in the transient voltage drop adjustment coefficient; S * represents the maximum instantaneous power; s is the Laplace operator; n represents the number of the DC microgrid; K s is the synchronous power coefficient; U o is the output phase voltage; U g is the voltage amplitude; Indicates the initial value of the transient voltage drop adjustment coefficient.

6. The method according to claim 1, characterized in that The power system further includes an inverter corresponding to each of the DC microgrids; a DC bus in the DC microgrid is connected to an AC load through the inverter; The step of adjusting the transient voltage drop distribution between DC buses in each DC microgrid according to the transient voltage drop change rate includes: generating a corresponding high-frequency switching signal according to the transient voltage drop change rate; The inverter is controlled based on the high-frequency switching signal to adjust the transient voltage drop distribution between the DC buses in each of the DC microgrids.

7. A transient voltage drop distribution device for AC interconnection between multiple DC microgrids, characterized in that: Applied to a power system, the power system includes a plurality of DC microgrids, and the plurality of DC microgrids are interconnected to form an AC network; the device includes: The first determination module is used to determine the initial value of the transient voltage drop regulation coefficient and the change of the transient voltage drop regulation coefficient corresponding to each of the DC microgrids when there is an AC load fluctuation in the power system; and determine the target value of the transient voltage drop regulation coefficient corresponding to each of the DC microgrids according to the initial value of the transient voltage drop regulation coefficient and the change of the transient voltage drop regulation coefficient; A second determination module is used to determine the corresponding transient voltage drop change rate according to the transient voltage drop adjustment coefficient target value; wherein the product of the transient voltage drop adjustment coefficient target value corresponding to each of the DC microgrids and the corresponding transient voltage drop change rate is equal; A distribution module is used to adjust the transient voltage drop distribution between DC buses in each DC microgrid according to the transient voltage drop change rate to share the AC load fluctuation.

8. An electric power device, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

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

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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