Reactive power coordination method and device for flexible interconnection device in transformer area interconnected power distribution system

Abstract

The application discloses a reactive power coordination method and device of a flexible interconnection device in a transformer area interconnected power distribution system. The method of the application ensures that the remaining FID-VSC devices in the same set step by step adjust the active power output value within the rated capacity range, and further improves the reactive power output of the FID-VSC device at the low power factor load access feeder, by monitoring the fluctuation value of the feeder voltage in real time and comprehensively considering the power operation state of each FID-VSC device and the residual capacity condition of the device itself. The method of the application realizes dynamic adjustment of the feeder voltage at the AC / DC system interface, maintains the stability of the feeder voltage of the flexible interconnected power distribution system, and reduces the short-time voltage drop problem caused by the low power factor load. The method of the application can also effectively reduce the operation pressure of a single FID-VSC device and improve the utilization rate of the entire system device.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to a reactive power coordination method and apparatus for flexible interconnection devices in a distribution system with interconnected distribution areas. Background Technology

[0002] The distribution network is the terminal infrastructure of the power system, responsible for ensuring a stable power supply and high-quality power transmission. However, when a load with a low power factor is connected to an AC feeder, it can cause a drop in AC feeder voltage. To improve the stability of node voltage, reactive power compensation equipment is usually configured on the feeder side. In a transformer interconnection system using FID-VSC (Flexible Interaction Device-Voltage Sourced Converter), the FID-VSC equipment itself has four-quadrant power controllability, allowing for independent adjustment of reactive power within its rated capacity by a controller, achieving dynamic reactive power compensation and thus replacing the original reactive power compensation equipment. For the application of multiple FID-VSC devices in a flexible interconnection system, the reactive power output of a single FID-VSC device can be increased by coordinating their active power output, thus suppressing quasi-steady-state voltage fluctuations at the AC feeder, improving the utilization rate of equipment within the system, and reducing the operating pressure on a single FID-VSC device. Currently, there is a problem where the connection of a low-power-factor load to the AC feeder causes the connected FID-VSC device to provide reactive power compensation exceeding its rated capacity. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art.

[0004] To address this, the present invention proposes a reactive power coordination method for flexible interconnection devices in a distribution system with interconnected distribution areas. Based on the status of each FID-VSC device and its own remaining capacity operating conditions, the active power output of FID-VSC devices in the same set is adjusted in a stepwise manner to improve the reactive power output capability of FID-VSC devices at the feeder where low power factor loads are connected, thereby achieving dynamic reactive power compensation at the AC / DC connection point and alleviating the short-term voltage drop problem caused by low power factor loads.

[0005] Another objective of this invention is to provide a reactive power coordination device for flexible interconnection devices in a transformer substation interconnection power distribution system.

[0006] To achieve the above objectives, the present invention provides a reactive power coordination method for flexible interconnection devices in a transformer substation interconnection power distribution system, comprising:

[0007] Based on the multi-zone flexible interconnection power distribution system, the set of equipment numbers and the actual AC voltage value of the feeder connected to the low power factor load are obtained, and the AC voltage difference is obtained based on the comparison result between the actual AC voltage value and the rated AC voltage value of the feeder.

[0008] The maximum active power output of the equipment is calculated based on the required reactive power compensation reference value corresponding to the AC voltage difference and the rated operating capacity of the equipment itself. The judgment result of whether reactive power control needs to be carried out is obtained based on the comparison result between the actual active power output value and the maximum active power output value.

[0009] Based on the judgment result, the active power reference value that the remaining devices in the device quantity set need to be coordinated and controlled is calculated, and the additional active power value required for each device is calculated based on the remaining capacity of each device. The step power reference value of the device is then calculated based on the active power value.

[0010] The step-type power reference value is sent to the active power control loop of the remaining devices belonging to the same set of devices in the multi-area flexible interconnected power distribution system. The current reference signal of the device is calculated through feedback control and sent to the current inner loop control of the device to complete the step-type active power regulation.

[0011] The reactive power coordination method for flexible interconnection devices in the transformer substation interconnection power distribution system according to embodiments of the present invention further includes the following additional technical features:

[0012] In one embodiment of the present invention, the FID-VSC i device is pre-defined to belong to set m, and the actual AC voltage value V of the low power factor load connected to feeder i is detected. ac,i For the multi-station flexible interconnection power distribution system with n terminals, the steady-state power flow condition is as shown in equation (1):

[0013]

[0014] Where m represents the number of FID-VSC devices whose active power flows from the AC system to the DC system, k represents the AC feeder connected to the k-th FID-VSC device, h represents the number of FID-VSC devices whose active power flows from the DC system to the AC system, and j represents the AC feeder connected to the j-th FID-VSC device.

[0015] In one embodiment of the present invention, the actual AC voltage value V of the low power factor load connected to feeder i is... ac,i With the rated AC voltage value V of the feeder ac，rated A comparison is made, and the AC voltage difference V is obtained based on the comparison result. ac，e As shown in equation (2):

[0016] V ac,e =Vac,rated -V ac,i (2)

[0017] In one embodiment of the present invention, a PI controller is used to calculate the AC voltage difference V. ac，e The corresponding required reactive power compensation reference value Q req As shown in equation (3):

[0018] Q req =(K p +K i / s)×V ac,e (3)

[0019] In one embodiment of the present invention, based on the reactive power compensation reference value Q req With FID-VSC i's own rated operating capacity S i The maximum active power output P that the FID-VSC i device can achieve is calculated. max,i As shown in equation (4):

[0020]

[0021] In one embodiment of the present invention, the actual output value P of the active power of the FID-VSC i device is used. act,i Greater than or equal to the maximum active power output P max,i The comparison results of the limits yield the judgment result that reactive power control needs to be carried out, as shown in formula (5):

[0022] P act,i ≥P max,i (5)

[0023] In one embodiment of the present invention, based on the judgment result of reactive power control as needed, the active power reference value P of the remaining FID-VSC devices in the set m of the multi-area flexible interconnected power distribution system that needs to be coordinated and controlled is calculated. req As shown in equation (6):

[0024] P ref =P max,i -P act,i (6)

[0025] In one embodiment of the present invention, the remaining capacity of each FID-VSC device in the m-set is used as the weight to calculate the additional active power required for each FID-VSC device in the m-set. For the remaining capacity value S of the k-th FID-VSC device... k Required additional active power reference value P add,k The calculation method is as shown in equation (7):

[0026]

[0027] In one embodiment of the invention, in each power step adjustment stage, the active power reference value is increased by 10%. For the k-th FID-VSC device in set m, the step power setpoint reference value ΔP step,k As in equation (8):

[0028]

[0029] To achieve the above objectives, another aspect of the present invention provides a reactive power coordination device for flexible interconnection devices in a transformer substation interconnection power distribution system, comprising:

[0030] The AC voltage difference calculation module is used to obtain the set of equipment numbers and the actual AC voltage value of the feeder connected to the low power factor load based on the multi-area flexible interconnection power distribution system, and to obtain the AC voltage difference based on the comparison result of the actual AC voltage value and the rated AC voltage value of the feeder.

[0031] The reactive power control comparison and judgment module is used to calculate the maximum active power output of the equipment based on the required reactive power compensation reference value corresponding to the AC voltage difference and the rated operating capacity of the equipment itself, and to determine whether reactive power control needs to be carried out based on the comparison result between the actual active power output value and the maximum active power output value.

[0032] The power reference value calculation module is used to calculate the active power reference value that the remaining devices in the device quantity set need to be coordinated and controlled based on the judgment result, and to calculate the additional active power value required by each device based on the remaining capacity of each device, and to calculate the step power setpoint reference value of the device based on the active power value.

[0033] The power distribution system feedback control module is used to send the step-type power setpoint reference value to the active power control loop of the remaining equipment belonging to the same set of equipment in the multi-area flexible interconnected power distribution system. The current reference signal of the equipment is calculated through feedback control, and the current reference signal is sent to the current inner loop control of the equipment to complete the step-type active power regulation.

[0034] The reactive power coordination method and apparatus for flexible interconnection devices in the transformer substation interconnection power distribution system of this invention effectively reduces the working pressure of a single FID-VSC converter and ensures that each FID-VSC device provides the required active power output within its capacity. Ultimately, by increasing the reactive power output of FID-VSC devices connected to feeders with low power factors, the dynamic adjustment function of the feeder voltage at the AC / DC system interface is realized.

[0035] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0036] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0037] Figure 1 This is a flowchart of a reactive power coordination method for flexible interconnection devices in a distribution system interconnected with transformer substations, according to an embodiment of the present invention.

[0038] Figure 2 This is a schematic diagram of a flexible interconnected power distribution system with low power factor loads according to an embodiment of the present invention;

[0039] Figure 3 This is a block diagram of the control structure of a flexible interconnection device in a distribution system interconnected with transformer substations according to an embodiment of the present invention.

[0040] Figure 4 This is a schematic diagram of the reactive power coordination device of the flexible interconnection device in the transformer substation interconnection power distribution system according to an embodiment of the present invention. Detailed Implementation

[0041] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0042] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0043] The reactive power coordination method and apparatus for flexible interconnection devices in a distribution system with interconnected substations, according to embodiments of the present invention, are described below with reference to the accompanying drawings.

[0044] Figure 1 This is a flowchart of a reactive power coordination method for flexible interconnection devices in a distribution system interconnected by a transformer substation, according to an embodiment of the present invention.

[0045] like Figure 1 As shown, the method includes, but is not limited to, the following steps:

[0046] S1, based on the multi-zone flexible interconnection power distribution system, obtain the set of equipment quantity and the actual AC voltage value of the feeder connected to the low power factor load, and obtain the AC voltage difference based on the comparison result between the actual AC voltage value and the rated AC voltage value of the feeder.

[0047] S2, calculate the maximum active power output of the equipment based on the reference value of reactive power compensation required according to the AC voltage difference and the rated operating capacity of the equipment itself, and determine whether reactive power control needs to be carried out based on the comparison between the actual active power output and the maximum active power output.

[0048] S3, based on the judgment result, calculate the reference value of active power that the remaining equipment in the equipment quantity set needs to be coordinated and controlled, and calculate the additional active power value required by each equipment based on the remaining capacity of each equipment, and calculate the step power reference value of the equipment based on the active power value.

[0049] S4 sends the step-type power setpoint reference value to the active power control loop of the remaining equipment belonging to the same set of equipment in the multi-area flexible interconnected power distribution system. The current reference signal of the equipment is calculated through feedback control and sent to the current inner loop control of the equipment to complete the step-type active power regulation.

[0050] According to the reactive power coordination method of the flexible interconnection device in the transformer substation interconnection power distribution system of the present invention, the active power output value of the FID-VSC device in the same set is adjusted in a stepwise manner according to the status of each FID-VSC device and its own remaining capacity operating conditions, so as to improve the reactive power output capability of the FID-VSC device at the feeder where the low power factor load is connected, realize dynamic reactive power compensation at the AC / DC connection, and alleviate the short-term voltage drop problem caused by low power factor load.

[0051] The reactive power coordination method of the flexible interconnection device in the transformer substation interconnection power distribution system according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The method of the present invention may specifically include the following steps:

[0052] (1) Construct a flexible interconnected power distribution system for n transformer substations containing loads with low power factors. This system consists of AC substations 1 to n, connected via distribution transformers 1 to n and AC feeders 1 to n, respectively. The system also includes FID-VSCs 1 to n, completing the flexible interconnection of multiple substations. Low power factor loads are connected to AC distribution substation i via AC feeder i and distribution transformer i, such as... Figure 2 As shown.

[0053] For this flexible interconnected system with n terminals, the steady-state power flow condition is as shown in formula (1).

[0054]

[0055] In formula (1), m represents the number of FID-VSC devices from the AC system to the DC system, k represents the AC feeder connected to the k-th FID-VSC device, h represents the number of FID-VSC devices from the DC system to the AC system, and j represents the AC feeder connected to the j-th FID-VSC device.

[0056] (2) To prevent the FID-VSC device connected to AC feeder i from exceeding its rated apparent power due to reactive power when a low power factor load is connected to the AC feeder, it is first necessary to detect the set to which FID-VSC i belongs (in this invention, FID-VSC i belongs to set m as an example, i.e., FID-VSC i provides active power to the DC system through the AC system) and the actual AC voltage value of the low power factor load connected to feeder i, and record it as V. ac,i .

[0057] (3) According to step (2), the actual detected AC voltage value (V) of feeder i is... ac,i ) and the rated AC voltage value of the feeder (V ac，rated By comparing these values, the AC voltage difference (V) can be obtained. ac，e ), as in formula (2).

[0058] V ac,e =V ac,rated -V ac,i (2)

[0059] (4) Based on step (3), calculate the AC voltage difference (V) using a PI controller. ac，e The corresponding required reactive power compensation reference value (Q) req ), as in formula (3).

[0060] Q req =(K p +K i / s)×V ac,e (3)

[0061] (5) Based on step (4), the obtained reactive power compensation reference value (Q) req ) and FID-VSC i's own rated operating capacity S i Combining these factors, the maximum achievable active power output (P) of the FID-VSC i device can be calculated. max,i ), as in formula (4).

[0062]

[0063] (6) Combining step (5), based on the actual output value (P) of the active power of the FID-VSC i device during operation. act,i), determine whether reactive power control is needed. As in formula (5), if the actual output power (P act,i ) is greater than or equal to the maximum active power output (P) max,i If the limit is reached, then the reactive power coordination of the flexible interconnection device proposed in this invention can be carried out.

[0064] P act,i ≥P max,i (5)

[0065] (7) Based on the conditions in step (6), calculate the reference value of active power (P) of the remaining FID-VSC devices in the set m of the multi-area flexible interconnection system that require coordinated control. req ), as in formula (6).

[0066] P ref =P max,i -P act,i (6)

[0067] (8) Combining step (7), and using the remaining capacity of each FID-VSC device in set m as the weight (the difference between the rated capacity of the device and the actual capacity of the system during operation), calculate the additional active power required for each FID-VSC device in the set. Therefore, for the k-th FID-VSC device, the remaining capacity value is denoted as S. k The required additional active power reference value is denoted as P. add,k The calculation method is as shown in formula (7).

[0068]

[0069] (9) According to step (8), in order to prevent the remaining FID-VSC devices in set m from exceeding their rated capacity after the addition of active power, the present invention adopts an active power step-by-step adjustment stage. In each power step-by-step adjustment stage, the active power reference value is increased by only 10%. Therefore, for the k-th FID-VSC device in set m, its step-by-step power reference value (ΔP) is... step,k As shown in formula (8).

[0070]

[0071] (10) Combining with step (9), the active power setpoint considering the step-by-step adjustment stage will be... The active power control loop is sent to the remaining FID-VSC devices belonging to the same set in the multi-zone flexible interconnected power distribution system. Through feedback control, the d-axis current reference value of the FID-VSC device is calculated, and this d-axis current reference signal is sent to the FID-VSC's inner current loop control to complete the step-by-step active power regulation. For the k-th FID-VSC device, the control structure block diagram is as follows: Figure 3 As shown.

[0072] (11) Repeat steps (8)-(10). When the remaining capacity of a single FID-VSC device is exhausted, the device will exit the coordination control loop. At the same time, when the remaining FID-VSC devices in the same set complete the coordination and compensation of the active power deficit required by the FID-VSC devices at the AC feeder for reactive power regulation (i.e., the active power reference value P in formula (7)). req (becomes zero), or when the remaining capacity of the remaining FID-VSC devices in the set is exhausted (i.e., the remaining capacity value S of the device in formula (7) becomes zero). k When the reactive power coordination link of the flexible interconnection device is reduced to zero, the reactive power coordination link is terminated.

[0073] The reactive power coordination method for flexible interconnection devices in a multi-regional flexible interconnection power distribution system according to embodiments of the present invention addresses the problem of quasi-steady-state voltage drop on connecting feeders caused by the access of loads with low power factors in a multi-regional flexible interconnection power distribution system, and the problem that FID-VSC devices connected to AC feeders may exceed their rated capacity when providing reactive power support. By real-time monitoring of feeder voltage fluctuations and comprehensively considering the power operating status of each FID-VSC device and its own remaining capacity, the method ensures that the remaining FID-VSC devices in the same set adjust their active power output in steps within their rated capacity range. This improves the reactive power output of FID-VSC devices at the feeder access point for low power factor loads, achieves dynamic adjustment of feeder voltage at the AC / DC system interface, maintains the stability of feeder voltage in the flexible interconnection power distribution system, and mitigates the short-term voltage drop problem caused by low power factor loads. Furthermore, the method of the present invention can effectively reduce the operating pressure of individual FID-VSC devices and improve the utilization rate of the entire system equipment.

[0074] It is understood that the method involved in this invention is simple, requires no additional equipment, only a modification to a traditional controller, and is highly implementable, providing guidance and reference for future practical engineering applications. The step-type active power regulation ratio involved in this invention is not limited to 10% and can be adjusted according to actual system parameters and control requirements. Furthermore, the low power factor load involved in this invention is not limited to centralized connection to a single feeder, but is also applicable to connections to multiple feeders or distributed connections.

[0075] To achieve the above embodiments, such as Figure 4 As shown, this embodiment also provides a reactive power coordination device 10 for flexible interconnection devices in the distribution system of transformer substations. The device 10 includes an AC voltage difference calculation module 100, a reactive power control comparison and judgment module 200, a power reference value calculation module 300, and a distribution system feedback control module 400.

[0076] The AC voltage difference calculation module 100 is used to obtain the set of equipment quantity and the actual AC voltage value of the feeder connected to the low power factor load based on the flexible interconnection distribution system of multiple distribution areas, and to obtain the AC voltage difference based on the comparison result between the actual AC voltage value and the rated AC voltage value of the feeder.

[0077] The reactive power control comparison and judgment module 200 is used to calculate the maximum active power output of the equipment based on the required reactive power compensation reference value corresponding to the AC voltage difference and the rated operating capacity of the equipment itself, and to determine whether reactive power control needs to be carried out based on the comparison result between the actual active power output value and the maximum active power output value.

[0078] The power reference value calculation module 300 is used to calculate the active power reference value that the remaining devices in the device quantity set need to be coordinated and controlled based on the judgment result and the remaining capacity of each device to calculate the additional active power value required by each device, and to calculate the step power setpoint reference value of the device based on the active power value.

[0079] The power distribution system feedback control module 400 is used to send the step-type power setpoint reference value to the active power control loop of the remaining equipment belonging to the same set of equipment in the multi-area flexible interconnected power distribution system. The current reference signal of the equipment is calculated through feedback control and sent to the current inner loop control of the equipment to complete the step-type active power regulation.

[0080] The reactive power coordination device of the flexible interconnection device in the transformer substation interconnection power distribution system according to an embodiment of the present invention monitors the fluctuation value of the feeder voltage in real time and comprehensively considers the power operation status of each FID-VSC device and its own remaining capacity conditions. This ensures that the active power output of the FID-VSC devices in the same set is adjusted in steps within their rated capacity range, thereby increasing the reactive power output of the FID-VSC devices at the feeder where low power factor loads are connected. This achieves dynamic adjustment of the feeder voltage at the AC / DC system interface, maintains the stability of the feeder voltage in the flexible interconnection power distribution system, and mitigates the short-term voltage drop problem caused by low power factor loads. It effectively reduces the operating pressure of individual FID-VSC devices and improves the utilization rate of system equipment.

[0081] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0082] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

Claims

1. A reactive power coordination method for flexible interconnection devices in a transformer substation interconnection power distribution system, characterized in that, Includes the following steps: Based on the multi-zone flexible interconnected power distribution system, the actual AC voltage value of the feeder connected to the equipment set and low power factor loads is obtained, and the AC voltage difference is obtained based on the comparison between the actual AC voltage value and the rated AC voltage value of the feeder; wherein, FID-VSC is preset. i The equipment belongs to m Collection, detection of low power factor loads connected to the feeder i Actual AC voltage value V ac,i For those containing n The steady-state power flow condition of the multi-station flexible interconnected power distribution system at the terminal is as shown in equation (1): （1） in, m This indicates the number of FID-VSC devices from which active power flows from the AC system into the DC system. k Indicates the first k The AC feeder connected to each FID-VSC device h This indicates the number of FID-VSC devices from which active power flows from the DC system into the AC system. j Indicates the first j The AC feeder connected to each FID-VSC device; Connect low power factor loads to the feeder i Actual AC voltage value V ac,i With the rated AC voltage of the feeder V ac，rated A comparison is made, and the AC voltage difference is obtained based on the comparison results. V ac，e As in equation (2): （2） Calculate AC voltage difference using a PI controller V ac，e Corresponding to the required reactive power compensation reference value Q req As in equation (3): （3） The maximum active power output of the equipment is calculated based on the required reactive power compensation reference value corresponding to the AC voltage difference and the equipment's rated operating capacity. A judgment on whether reactive power control is needed is then made based on the comparison between the actual active power output and the maximum active power output. The reactive power compensation reference value is used as the basis for determining whether reactive power control is required. Q req With FID-VSC i Rated operating capacity S i FID-VSC was calculated. i Maximum active power output that the equipment can achieve P max,i As in equation (4): （4） According to FID-VSC i Actual output value of active power of equipment P act,i Greater than or equal to the maximum active power output P max,i The comparison results of the limit values ​​yield the judgment result that reactive power control needs to be carried out, as shown in formula (5): （5） Based on the judgment result, the active power reference value that the remaining devices in the device quantity set need to be coordinated and controlled is calculated, and the additional active power value required for each device is calculated based on the remaining capacity of each device. The step power reference value of the device is then calculated based on the active power value. The step-type power reference value is sent to the active power control loop of the remaining devices belonging to the same set of devices in the multi-area flexible interconnected power distribution system. The current reference signal of the device is calculated through feedback control and sent to the current inner loop control of the device to complete the step-type active power regulation.

2. The method according to claim 1, characterized in that, Based on the results of reactive power control assessments, calculate the power distribution system for multiple transformer substations with flexible interconnection. m The reference value of active power that needs to be coordinated and controlled for the remaining FID-VSC devices in the collection. P req As in equation (6): （6）。 3. The method according to claim 2, characterized in that, Will m The remaining capacity of each FID-VSC device in the set is used as the weight to calculate the weight. m The additional active power required by each FID-VSC device in the set, for the first... k Remaining capacity of each FID-VSC device S k Required additional active power reference value P add,k The calculation method is as shown in equation (7): （7）。 4. The method according to claim 3, characterized in that, In each power step adjustment phase, the active power reference value is increased by 10%. m The set of k One FID-VSC device, step power setpoint reference value As shown in equation (8): （8）。 5. A reactive power coordination device for a flexible interconnection device in a transformer substation interconnection power distribution system, used to implement any one of the methods described in claims 1-4, characterized in that, include: The AC voltage difference calculation module is used to obtain the set of equipment numbers and the actual AC voltage value of the feeder connected to the low power factor load based on the multi-area flexible interconnection power distribution system, and to obtain the AC voltage difference based on the comparison result of the actual AC voltage value and the rated AC voltage value of the feeder. The reactive power control comparison and judgment module is used to calculate the maximum active power output of the equipment based on the required reactive power compensation reference value corresponding to the AC voltage difference and the rated operating capacity of the equipment itself, and to determine whether reactive power control needs to be carried out based on the comparison result between the actual active power output value and the maximum active power output value. The power reference value calculation module is used to calculate the active power reference value that the remaining devices in the device quantity set need to be coordinated and controlled based on the judgment result, and to calculate the additional active power value required by each device based on the remaining capacity of each device, and to calculate the step power setpoint reference value of the device based on the active power value. The power distribution system feedback control module is used to send the step-type power setpoint reference value to the active power control loop of the remaining equipment belonging to the same set of equipment in the multi-area flexible interconnected power distribution system. The current reference signal of the equipment is calculated through feedback control, and the current reference signal is sent to the current inner loop control of the equipment to complete the step-type active power regulation.

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