Power cooperative control method and system of flexible interconnection system, medium and equipment
By deploying flexible interconnection equipment and a hierarchical distributed control system between substations, the problem of uneven load across multiple plant areas was solved, enabling dynamic power allocation and energy optimization across substation areas, reducing electricity costs and improving system energy utilization.
Patent Information
- Application Number
- CN202511737898.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-25
- Publication Date
- 2026-02-06
AI Technical Summary
The uneven distribution of load in the time and space during the coordinated operation of multiple power plants leads to differences in power transmission, which affects the stability of the power grid and increases electricity costs. Traditional power transmission modes are difficult to achieve dynamic allocation across power plant areas.
Flexible interconnection equipment is deployed between key substations, and a hierarchical distributed control system is adopted. The main control device generates total power commands, which are then decomposed into commands for individual converters by the sub-control devices. Combined with the SOC balancing strategy, dynamic power balance and energy optimization scheduling of the two substations are achieved.
It achieves dynamic power balance between the two substations, reduces the company's electricity costs, mitigates the impact of grid fluctuations, and improves system energy utilization and battery life.
Smart Images
Figure CN121484948A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to a power collaborative control method, system, medium and equipment of a flexible interconnection system, and belongs to the technical field of flexible interconnection systems. BACKGROUND
[0002] With the continuous expansion of enterprise power grid scale and the large-scale grid connection of renewable energy, the technical problem of unbalanced load space-time distribution is generally faced in multi-factory area collaborative operation. This asymmetric load feature leads to significant differences in power transmission of external tie lines of each substation, which not only affects the stability of power grid operation, but also increases the overall electricity cost of the enterprise due to the increase of peak demand. The traditional power transmission mode based on rigid tie lines is limited by the synchronization constraint of alternating current systems, and it is difficult to realize dynamic power allocation across substation areas. SUMMARY
[0003] The technical problem to be solved by the present application is to overcome the defects of the prior art. The present application considers deploying flexible interconnection devices between key substations and proposes a corresponding control strategy. Through this strategy, excess power on the power surplus side can be transferred to the power deficit side in a timely manner, thereby realizing dynamic power balance and energy optimization scheduling between the two substations. The control strategy aims to effectively smooth the power fluctuation of the tie line, reduce the peak demand of the enterprise, and ultimately realize economic operation of the power grid and minimization of electricity cost, thereby providing a power collaborative control method, system, medium and equipment of a flexible interconnection system, which can balance the space-time mismatch of surplus power and deficit power in real time, thereby realizing dynamic power balance and energy optimization scheduling between the two substations. At the same time, the SOC balancing strategy is considered in the power distribution link of multiple converters, and the charging and discharging power command is issued according to the adjustable balancing speed, which improves the energy utilization rate of the system and prolongs the service life of the battery.
[0004] To solve the above technical problems, the present application is realized by the following technical scheme.
[0005] In a first aspect, the present application discloses a power collaborative control method of a flexible interconnection system, comprising: S1: constructing a hierarchical distributed control system architecture, the architecture comprising a main control device at the upper layer, sub-control devices A and B at the intermediate layer, and A-zone converter groups and B-zone converter groups at the execution layer; S2: collecting the grid tie line power P1 of the A-zone substation through the sub-control device A, and collecting the grid tie line power P2 of the B-zone substation through the sub-control device B; at the same time, uploading the real-time operating parameters of each converter in the A-zone converter groups and the B-zone converter groups to the corresponding sub-control device, the real-time operating parameters at least including real-time power, chargeable and dischargeable power adjustment capability, and battery group SOC; S3: The main control device adjusts the total active power instructions P3 and P4 according to a preset power coordination strategy based on P1, P2 and the total chargeable and dischargeable power regulation capabilities dP1 and dP2 of the converter groups in each area, and sends the total active power instructions P3 and P4 to the sub-control device A and the sub-control device B, respectively; S4: After receiving the total active power instructions P3 or P4, the sub-control device A and the sub-control device B decompose the total power instructions into power instructions for individual converters based on the SOC of the battery pack of each converter in the converter group under their jurisdiction, and send the power instructions to the corresponding converters for execution.
[0006] Further, in step S3, the directions of the grid-connected tie-line power P1 and P2 are defined as positive for power export and negative for power import; the directions of the active instructions P3 and P4 of the converters in the flexible interconnection system are defined as positive for charging and negative for discharging; the total chargeable power regulation capabilities of the converters in the flexible interconnection system are dP1 and dP2, and the total dischargeable power regulation capabilities are dP3 and dP4, and the constraint condition is satisfied.
[0007] Further, the preset power coordination strategy includes the following six operating modes: Mode one: when P1≥0 and P2>0, the power instructions P3 and P4 sent by the main control device are P3=min(|dP1|,|P1|) and P4=min(|dP2|,|P2|); Mode two: when P1≥0 and P2<0, and P1≥|P2|, the power instructions P3 and P4 sent by the main control device are P3=min(|dP1|,|dP4|,|P2|) and P4=-min(|dP1|,|dP4|,|P2|); Mode three: when P1≥0 and P2<0, and P1<|P2|, the power instructions P3 and P4 sent by the main control device are P3=min(|dP1|,|dP4|,|P1|) and P4=-min(|dP1|,|dP4|,|P1|); Mode four: when P1≤0 and P2>0, and P2≥|P1|, the power instructions P3 and P4 sent by the main control device are P3=-min(|dP2|,|dP3|,|P1|) and P4=min(|dP2|,|dP3|,|P1|); Mode five: when P1≤0 and P2>0, and P2<|P1|, the power instructions P3 and P4 sent by the main control device are P3=-min(|dP2|,|dP3|,|P2|) and P4=min(|dP2|,|dP3|,|P2|); Mode six: when P1≤0 and P2<0, the power instructions P3 and P4 sent by the main control device are P3=-min(|dP3|,|P1|) and P4=-min(|dP4|,|P2|).
[0008] Further, in step S4, the specific implementation of the SOC equalization distribution strategy is as follows: For a converter group composed of n converters, the power instruction of a single converter i is P AGCi determined by the following formula: ; Wherein, P avg is the average power instruction of all converters that can participate in power distribution, SOC avg is the average SOC coefficient of all energy storage units in the converter group, SOC i is the real-time SOC of the energy storage unit connected to the i-th converter, k is the SOC equalization speed adjustment coefficient greater than or equal to 0.
[0009] Further, the value of the SOC equalization speed adjustment coefficient k needs to ensure that the single converter power instruction Pi* calculated according to the SOC equalization distribution strategy does not exceed the power limit of the converter, and ensures that the power directions of all converters in the converter group are consistent at the same time.
[0010] In a second aspect, the present application discloses a flexible interconnection system for implementing the power coordination control method as described in the first aspect, comprising: a main control device configured to execute the power coordination strategy and generate a total active power instruction; a sub-control device A and a sub-control device B, respectively in communication connection with the main control device, configured to collect grid-connected tie-line power and real-time operating parameters of the converter group, and receive the total active power instruction; a converter group in region A and a converter group in region B, respectively in communication connection with the corresponding sub-control device, each converter being connected with an energy storage battery, and being configured to execute the decomposed single converter power instruction.
[0011] In a third aspect, the present application discloses a computer readable storage medium storing one or more programs, the one or more programs including instructions that, when executed by a computing device, cause the computing device to perform the method of the first aspect.
[0012] In a fourth aspect, the present application discloses a computer device, comprising, one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for executing the method of the first aspect.
[0013] The beneficial effects achieved by the present application are: (1) In the present application, the grid-connected tie-line power can be collected in real time, the power imbalance degree between the two substations is judged, the bidirectional controllable characteristics of the flexible interconnection system converter are utilized, the power transmission direction and amplitude of the bidirectional converter are dynamically adjusted according to the control method proposed in the present application, and finally the power mutual aid mechanism between the two substations is formed, thereby maximizing the reduction of enterprise electricity cost and relieving the influence on the power grid fluctuation.
[0014] (2) In the present application, the single converter power instruction considers the preset SOC balancing algorithm, the SOC balancing speed is adjusted by the k value adjustment coefficient, the battery consistency between the battery stacks is ensured, the circulating current is avoided, and the system safety is improved. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 It is a typical application scenario main wiring diagram of the flexible interconnection system described in the present application; Figure 2 It is a control topology diagram of the flexible interconnection system described in the present application; Figure 3 It is a curve of the converter power instruction varying with SOC under different k values in the charging state of the flexible interconnection system; Figure 4 It is a curve of the converter power instruction varying with SOC under different k values in the discharging state of the flexible interconnection system. DETAILED DESCRIPTION
[0016] The present application will be further described below in conjunction with the drawings. The following examples are only used to more clearly illustrate the technical solutions of the present application, and cannot be used to limit the protection scope of the present application.
[0017] Example 1, see Figure 1 This embodiment introduces a power coordination control method of a flexible interconnection system. As shown in FIG. A, two 110kV substations in area A and area B are respectively provided with independent power metering points. Due to different wind and light power generation scales and different load capacities on both sides, the uplink and downlink power flow is unbalanced. The flexible interconnection system adopts a double-end AC / DC+ battery pack coupling topology, realizes cross-station energy flow, and can transfer the excess power on the power surplus side to the power shortage side for timely release.
[0018] Referring to Figure 2 The power coordination control of the flexible interconnection system of the above-mentioned topology adopts the method described in the present application, which includes the following steps: Step 1, construct a hierarchical distributed networking scheme, the main control device is connected with the sub-control device A and the sub-control device B, the sub-control device A and the sub-control device B are connected with the flexible interconnection system A area converter and the B area converter respectively, and a fast communication protocol such as GOOSE is used between devices; a high-precision real-time monitoring module is integrated in the control device; Step 2: the sub-control device A collects the CT and PT values of the A area substation to calculate the grid tie line power P1, and the sub-control device B collects the CT and PT values of the B area substation to calculate the grid tie line power P2. At the same time, the real-time power, chargeable and dischargeable power regulation capability, and battery group SOC information of the AB area converter are communicated to the sub-control device; Step 3: the main control device combines the relevant data in step 1 and step 2 to quantify the power imbalance degree between the two substations, generates charge and discharge active power instructions P3 and P4 respectively, and issues them to the sub-control device A and the sub-control device B. The sub-control device combines the real-time power, chargeable and dischargeable power regulation capability, and battery group SOC information of the converter it controls to generate unit instruction distribution to the converter for execution.
[0019] The power calculation method used in step 3 is as follows: The grid tie line power P1 and P2 are defined as positive for outward transmission and negative for feeding in. The active instructions P3 and P4 of the flexible interconnection system are positive for charging and negative for discharging. The total chargeable power regulation capability of the AB area converter of the flexible interconnection system is dP1 and dP2, and the total dischargeable power regulation capability is dP3 and dP4. The following constraints are met: |dP1|+|dP3|=|dP2|+|dP4|=2C; |P3|,|P4|≤C; In the above formula, C is the rated power of the energy storage converter.
[0020] (1) If P1>=0, P2>0, AB area power is transmitted outward, then the power instructions issued by the main control device to the sub-control device AB are P3=min(|dP1|,|P1|), P4=min(|dP2|,|P2|) respectively; (2) If P1>=0, P2<0, P1>=|P2|, A area power is transmitted outward, and B area power is fed in, then the power instructions issued by the main control device to the sub-control device AB are P3=min(|dP1|,|dP4|,|P2|), P4=-min(|dP1|,|dP4|,|P2|) respectively; (3) If P1>=0, P2<0, P1<|P2|, A area power is transmitted outward, and B area power is fed in, then the power instructions issued by the main control device to the sub-control device AB are P3=min(|dP1|,|dP4|,|P1|), P4=-min(|dP1|,|dP4|,|P1|) respectively; (4) If P1<=0, P2>0, P2>=|P1|, A area power feeding, B area power sending, then the power instructions issued by the main control device to the sub-control device AB are P3=-min(|dP2|,|dP3|,|P1|), P4=min(|dP2|,|dP3|,|P1|) respectively; (5) If P1<=0, P2>0, P2<|P1|, A area power feeding, B area power sending, then the power instructions issued by the main control device to the sub-control device AB are P3=-min(|dP2|,|dP3|,|P2|), P4=min(|dP2|,|dP3|,|P2|) respectively; (6) If P1<=0, P2<0, AB area power feeding, then the power instructions issued by the main control device to the sub-control device AB are P3=-min(|dP3|,|P1|), P4=-min(|dP4|,|P2|) respectively.
[0021] After the sub-control device AB receives the power instructions of the main control device, it needs to decompose and issue them, and the target is mainly to achieve balanced distribution based on the SOC of each battery pack. The power distribution strategy of each converter is as follows: ; Wherein, P avg is the average power instruction of all converters that can participate in power distribution, SOC avg is the average SOC coefficient of all energy storage units in the converter group, SOC i is the real-time SOC of the energy storage unit connected to the i-th converter, k is the SOC balancing speed adjustment coefficient greater than or equal to 0, which represents the balancing speed of the SOC, k The greater the value is, the faster the SOC balancing speed is, k The value is 0, which means that the power is evenly distributed, and there is no balancing function at this time. k The value of needs to consider the power limit value of a single PCS, and there is no circulating current between multiple PCSs inside, and multiple PCSs are not allowed to have charging and discharging states at the same time.
[0022] When the energy storage is in a charging state, as shown in Figure 3 , P max is the power limit value of the PCS, k The value of can be dynamically adjusted within the range of 0- k max to ensure that the power of a single PCS does not exceed the limit.
[0023] When the energy storage is in a discharging state, as shown inFigure 4 As shown, P max The power limit for PCS. k The value can be 0- k max Dynamic adjustments are made within the specified range to ensure that the power of a single PCS does not exceed the limit.
[0024] This invention can transfer excess power from the power surplus side to the power deficit side for timely release, thereby achieving dynamic power balance and optimized energy scheduling between the two substations. This control strategy aims to effectively smooth power fluctuations in tie lines, reduce peak demand for enterprises, and ultimately minimize the economic operation of the power grid and electricity costs.
[0025] Example 2, based on the same inventive concept as Example 1, introduces a flexible interconnection system for implementing the power cooperative control method as described in Example 1, comprising: The main control unit is configured to execute the power coordination strategy and generate a total active power command; Sub-control device A and sub-control device B are respectively connected to the main control device and are configured to collect grid-connected tie-line power and real-time operating parameters of the converter group, and receive total active power commands. The converter groups in Zone A and Zone B are respectively connected to their corresponding sub-control devices. Each converter is connected to an energy storage battery and is configured to execute the decomposed power commands of a single converter.
[0026] Example 3, based on the same inventive concept as Example 1, describes a computer-readable storage medium storing one or more programs, the one or more programs including instructions that, when executed by a computing device, cause the computing device to perform the method described in the first aspect.
[0027] Example 4, based on the same inventive concept as Example 1, describes a computer device including one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for performing the method described in the first aspect.
[0028] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0029] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.
[0030] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.
[0031] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flowcharts and / or blocks Figure 1 means for functionally implementing the steps listed in the flowchart block or blocks.
[0032] The above description is only preferred embodiment of the present application, it should be pointed out that, for those skilled in the art, without departing from the technical principles of the present application, can also make a number of improvements and variations, these improvements and variations should also be considered as the protection scope of the present application.
Claims
1. A power cooperative control method for a flexible interconnected system, characterized in that, include: S1: Construct a hierarchical distributed control system architecture, which includes an upper-level main control device, an intermediate-level sub-control device A and sub-control device B, and an A-zone converter group and a B-zone converter group in the execution layer. S2: The grid-connected tie line power P1 of substation A is collected through sub-control device A, and the grid-connected tie line power P2 of substation B is collected through sub-control device B; at the same time, the real-time operating parameters of each converter in the converter group of area A and the converter group of area B are sent to the corresponding sub-control device. The real-time operating parameters include at least real-time power, chargeable and dischargeable power adjustment capability and battery pack SOC. S3: Based on P1, P2 and the total chargeable and dischargeable power regulation capabilities dP1 and dP2 of each area converter group collected in step S2, the main control device generates total active power commands P3 and P4 according to the preset power coordination strategy, and sends them to the sub-control device A and sub-control device B respectively. S4: After receiving the total active power command P3 or P4, the sub-control device A and sub-control device B, based on the battery pack SOC of each converter in the converter group under their jurisdiction, adopt the SOC equalization allocation strategy to decompose the total power command into power commands for individual converters and send them to the corresponding converters for execution.
2. The power cooperative control method for a flexible interconnected system according to claim 1, characterized in that, In step S3, the directions of grid-connected tie line power P1 and P2 are defined as follows: power transmission is positive and power input is negative; the directions of active power commands P3 and P4 of the flexible interconnected system converter are defined as follows: charging is positive and discharging is negative; the total rechargeable power regulation capability of the flexible interconnected system converter is dP1 and dP2, and the total dischargeable power regulation capability is dP3 and dP4, and the constraints are satisfied.
3. The power coordination control method for a flexible interconnected system according to claim 2, characterized in that, The preset power coordination strategy includes the following six operating modes: Mode 1: When P1≥0 and P2>0, the power commands issued by the main control device are P3=min(|dP1|,|P1|) and P4=min(|dP2|,|P2|). Mode 2: When P1≥0 and P2<0, and P1≥|P2|, the power command issued by the main control device is P3=min(|dP1|,|dP4|,|P2|), P4=-min(|dP1|,|dP4|,|P2|); Mode 3: When P1≥0 and P2<0, and P1<|P2|, the power command issued by the main control device is P3=min(|dP1|,|dP4|,|P1|), P4=-min(|dP1|,|dP4|,|P1|); Mode 4: When P1≤0 and P2>0, and P2≥|P1|, the power command issued by the main control device is P3=-min(|dP2|,|dP3|,|P1|), P4=min(|dP2|,|dP3|,|P1|); Mode 5: When P1≤0 and P2>0, and P2<|P1|, the power command issued by the main control device is P3=-min(|dP2|,|dP3|,|P2|), P4=min(|dP2|,|dP3|,|P2|); Mode 6: When P1≤0 and P2<0, the power commands issued by the main control device are P3=-min(|dP3|,|P1|) and P4=-min(|dP4|,|P2|).
4. The power cooperative control method for a flexible interconnected system according to claim 1, characterized in that, In step S4, the specific implementation of the SOC balanced allocation strategy is as follows: For a converter group consisting of n converters, the power command of a single converter i is... P AGCi Determined by the following formula: ； in, P avg The average power command for all converters that can participate in power sharing. SOC avg This represents the average SOC coefficient of all energy storage units within the converter group. SOC i Let SOC be the real-time state of charge (SOC) of the energy storage unit connected to the i-th converter. k The SOC equalization speed adjustment coefficient is greater than or equal to 0.
5. The power coordination control method for a flexible interconnected system according to claim 4, characterized in that, The value of the SOC equalization speed adjustment coefficient k must ensure that the power command Pi* of a single converter calculated according to the SOC equalization allocation strategy does not exceed the power limit of that converter, and that the power direction of all converters in the converter group is consistent at the same time.
6. A flexible interconnected system for implementing the power cooperative control method as described in any one of claims 1 to 5, characterized in that, include: The main control unit is configured to execute the power coordination strategy and generate a total active power command; Sub-control device A and sub-control device B are respectively connected to the main control device and are configured to collect grid-connected tie-line power and real-time operating parameters of the converter group, and receive total active power commands. The converter groups in Zone A and Zone B are respectively connected to their corresponding sub-control devices. Each converter is connected to an energy storage battery and is configured to execute the decomposed power commands of a single converter.
7. A computer-readable storage medium for storing one or more programs, characterized in that, The one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any of the methods of claims 1 to 5.
8. A computer device, characterized in that, include, One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including instructions for performing the method of any of claims 1 to 5.