Distributed discrete dynamic power allocation method, system and device for constant current load and storage medium

Abstract

The present application relates to the technical field of power system control, in particular to a distributed discrete dynamic power distribution method, system and device for constant current load and a storage medium; local output power and local power generation capacity of each discrete sampling time of renewable energy source RES are acquired; the local capacity utilization rate is calculated according to the local output power and the local power generation capacity; the neighbor capacity utilization rate of the renewable energy source RES is acquired; the utilization rate deviation is calculated according to the local capacity utilization rate and the neighbor capacity utilization rate; the local voltage reference value of the renewable energy source RES is generated according to the utilization rate deviation, and the power distribution is dynamically adjusted according to the local voltage reference value; the output power and the dynamically changing power generation capacity of the local renewable energy source are collected at each discrete sampling time, so that the inherent stability risk of the continuous time CT control algorithm in the discrete time DT system is fundamentally avoided, and the stable operation of the system under the discrete sampling control is ensured.

Description

Technical Field

[0001] This invention relates to the field of power system control technology, specifically to a distributed discrete dynamic power allocation method, system, device, and storage medium for constant current loads. Background Technology

[0002] A constant current load (CCL) is a type of load whose current demand does not change with voltage. Common examples include LED lighting and electric vehicle charging. As the power demand of constant current loads (CCLs) increases, relying solely on a single renewable energy source (RES) to supply them will not guarantee the supply-demand balance of the DC power system. To ensure the stable operation of a DC power system with a large number of constant current loads (CCLs), the power demand of these CCLs needs to be distributed across multiple renewable energy sources (RES), laying the foundation for the safe and stable operation of the DC power system.

[0003] like Figure 1 The diagram illustrates the structure of existing control technologies. Existing constant current load (CCL) power allocation methods can be structurally categorized into distributed, centralized, and distributed methods. Distributed control methods offer advantages such as high flexibility and simple structure; however, increasing the power of the constant current load (CCL) can lead to a decrease in the DC power system bus voltage, posing a safety hazard. Centralized control methods utilize a communication network to collect information from all renewable energy resource reserves (RES) at the control center and distribute calculated control commands to each RES, avoiding the bus voltage drop problem. However, when the communication network fails, the centralized control method fails because the control center cannot receive information from some renewable energy RES. To address this issue, a distributed control method based on a communication network has been proposed. This method eliminates the need for a control center, achieving power allocation for the constant current load (CCL) solely through communication between the controllers of each renewable energy RES, thus avoiding control failures that may occur due to communication network failures.

[0004] However, existing distributed power distribution control methods for constant-current loads (CCLs) are mainly based on continuous-time (CT) control, while practical system-level control systems employ discrete-time (DT) control. Existing research results indicate that implementing CT control methods in discrete-time DT control systems leads to instability issues. Furthermore, existing power distribution control methods are often only applicable to DC power systems with a single bus, and cannot be applied to DC power systems with multiple buses. In addition, existing discrete-time DT control methods can only implement renewable energy sources (RES) with a fixed generating capacity, while in reality, the generating capacity of renewable energy RES changes with external environmental conditions. Summary of the Invention

[0005] To address the problems mentioned in the prior art, this invention proposes a distributed discrete dynamic power allocation method, system, device, and storage medium for constant current loads. By collecting discrete power output and discrete generation capacity, it solves the instability problem encountered when implementing the continuous-time CT control method in a discrete-time DT control system.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This invention proposes a distributed discrete dynamic power allocation method for constant current loads, applicable to DC power systems containing N renewable energy sources (RES), comprising the following steps:

[0008] S1. Obtain the local output power and local power generation capacity of the renewable energy RES at each discrete sampling time;

[0009] S2. Calculate the local capacity utilization rate based on the local output power and local power generation capacity;

[0010] S3, Obtain the neighbor's capacity utilization rate for renewable energy sources RES;

[0011] S4. Calculate the utilization rate deviation based on the local capacity utilization rate and the neighbor's capacity utilization rate;

[0012] S5. Generate a local voltage reference value for renewable energy RES based on the utilization deviation, and dynamically adjust the power allocation based on the local voltage reference value.

[0013] As a further improvement to the present invention, the process of S1 is as follows:

[0014] Obtain the first discrete sampling time. Output current and bus voltage of each renewable energy source RES;

[0015] The local output power is calculated based on the output current and bus voltage.

[0016] As a further improvement of the present invention, the expression for the local capacity utilization rate in S2 is as follows:

[0017]

[0018] In the formula: Indicates the first Local capacity utilization rate of each sampling point; Indicates the first Local power generation capacity at each sampling point; Indicates the first The local output power of each sampling point.

[0019] As a further improvement of the present invention, the neighbor capacity utilization rate includes:

[0020] The capacity utilization rate of the neighbors of the renewable energy source RES at the discrete sampling time is obtained using a communication network.

[0021] As a further improvement of the present invention, the S4 process is:

[0022] The utilization rate deviation is calculated as shown in the following formula:

[0023]

[0024] In the formula: Indicates utilization deviation; Indicates the first Local capacity utilization rate of each sampling point; The first Capacity utilization rate of each sampling point; Indicates the first The renewable energy RES and the first The weight of the communication link between renewable energy sources (RES) is 1 by default.

[0025] As a further improvement to the present invention, the S5 process is as follows:

[0026] The local voltage reference value is calculated using the following formula:

[0027]

[0028] In the formula: Indicates the first Local voltage reference values ​​at each sampling point; Indicates the first The local bus voltage at each sampling point; Indicates utilization deviation; Indicates the first Local power generation capacity at each sampling point; For control parameters, use positive values;

[0029] Input the local voltage reference value to the RES controller to adjust the output for dynamic power allocation.

[0030] As a further improvement of the present invention, the range of values ​​for the control parameters is as follows:

[0031]

[0032] In the formula: This represents the minimum capacity of all renewable energy sources (RES). The largest eigenvalue of the Laplacian matrix of the communication network; It is the largest eigenvalue of the admittance matrix of the electrical network.

[0033] This invention proposes a distributed discrete dynamic power distribution system for constant current loads, comprising:

[0034] The first acquisition module is used to acquire the local output power and local power generation capacity of the renewable energy RES at each discrete sampling time.

[0035] The first calculation module is used to calculate the local capacity utilization rate based on the local output power and local power generation capacity.

[0036] The second acquisition module is used to acquire the neighbor capacity utilization rate of renewable energy RES;

[0037] The second calculation module calculates the utilization deviation based on the local capacity utilization rate and the neighbor's capacity utilization rate;

[0038] The adjustment module is used to generate a local voltage reference value for renewable energy sources (RES) based on the utilization deviation, and to dynamically adjust the power allocation based on the local voltage reference value.

[0039] This invention proposes a distributed discrete dynamic power allocation device for constant current loads, comprising a processor and a memory, wherein the processor executes a computer program stored in the memory to implement the distributed discrete dynamic power allocation method for constant current loads as described above.

[0040] This invention proposes a computer-readable storage medium for storing a computer program, wherein the computer program, when executed by a processor, implements the distributed discrete dynamic power allocation method for constant current loads as described above.

[0041] Compared with the prior art, the present invention achieves the following technical effects:

[0042] Compared to existing distributed power allocation methods, which are based on continuous-time CT control theory and are prone to system oscillations or even instability, seriously threatening the safe operation of the system, this invention collects the output power and dynamically changing generation capacity of the local renewable energy RES in real time at each discrete sampling moment. Subsequent calculations are all based on the data at these discrete sampling points. By adopting a discrete design, this invention fundamentally avoids the inherent stability risks of continuous-time CT control algorithms when implemented in discrete-time DT systems, ensuring the stable operation of the system under discrete sampling control.

[0043] This invention introduces local capacity utilization as a variable, which does not depend on the absolute voltage value of a specific bus. Compared with traditional decentralized or distributed power allocation methods that usually rely on the measurement or regulation of a single common bus voltage for global coordination, this method is applicable to multi-bus DC power systems.

[0044] This invention dynamically collects and updates the power generation capacity of local renewable energy sources (RES) at each discrete sampling time. Based on changes in power generation capacity, it can dynamically adjust the capacity utilization rate and adjust the local voltage reference value, and dynamically redistribute the power load. This invention can always maintain a dynamic match between power allocation and current resources according to environmental fluctuations, significantly improving the robustness and operating efficiency of the system in real and changing environments.

[0045] This invention utilizes local information at discrete sampling points and interaction information with neighboring nodes, inherently possessing distributed characteristics. Compared to existing technologies, it avoids the excessive reliance of centralized control on a single communication network and effectively prevents the risk of control failure that may result from communication network malfunctions. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the existing technology;

[0047] Figure 2 This is a schematic diagram of the DC power system structure with a constant current load CCL according to the present invention;

[0048] Figure 3 For the present invention Flowchart of a distributed discrete dynamic power allocation method for a renewable energy RES;

[0049] Figure 4 A schematic diagram of the overall process of this invention;

[0050] Figure 5 This is a schematic diagram comparing the present invention with existing methods. Detailed Implementation

[0051] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0052] See Figure 4 This invention proposes a distributed discrete dynamic power allocation method for constant current loads, applicable to DC power systems containing N renewable energy sources (RES), comprising the following steps:

[0053] S1. Obtain the local output power and local power generation capacity of the renewable energy RES at each discrete sampling time;

[0054] S2. Calculate the local capacity utilization rate based on the local output power and local power generation capacity;

[0055] S3, Obtain the neighbor's capacity utilization rate for renewable energy sources RES;

[0056] S4. Calculate the utilization rate deviation based on the local capacity utilization rate and the capacity utilization rate.

[0057] S5. Generate a local voltage reference value for renewable energy RES based on the utilization deviation, and dynamically adjust the power allocation based on the local voltage reference value.

[0058] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments:

[0059] See Figure 2 The DC power system with constant current load CCL of the present invention includes: Renewable Energy RES: representing various types of power energy such as wind turbines and photovoltaic arrays with adjustable output power; Controller: representing the control unit of the renewable energy RES, used to implement a distributed discrete dynamic power allocation method; Constant current load CCL: representing various types of loads whose current demand does not change with voltage changes; Electrical network: represented by a thick solid line, used to transmit power from the renewable energy RES to the constant current load CCL; Communication network: represented by a dashed line, used to transmit necessary information for control between the controllers of the renewable energy RES. For each renewable energy RES, any renewable energy RES that can directly interact with it is its neighbor node.

[0060] For a DC power system with N renewable energy sources RES, the renewable energy sources RES are first sequentially numbered as follows: For the first For a renewable energy source RES, the specific distributed discrete power allocation method is as follows: Figure 3 As shown.

[0061] Step 1: Collect discrete sampling times using voltage and current sensors from the renewable energy source (RES). The information of output current and bus voltage, among which Representing the One sampling point, The sampling period is used to calculate the local output power, which is then used for subsequent calculations of local capacity utilization.

[0062] The local output power is calculated as follows:

[0063]

[0064] In the formula: Indicates the first The local bus voltage at each sampling point; Indicates the first The local output current at each sampling point; Indicates the first The local output power of each sampling point.

[0065] Collection of the first Local generation capacity of renewable energy RES at each sampling point The obtained local power generation capacity is also used for subsequent local capacity utilization calculations.

[0066] Step 2: Calculate the local capacity utilization rate of renewable energy RES, as shown in the following formula:

[0067]

[0068] In the formula: Indicates the first Local capacity utilization rate of each sampling point; Indicates the first Local power generation capacity at each sampling point; Indicates the first The local output power of each sampling point.

[0069] Step 3: The neighboring nodes of the local renewable energy source RES calculate their... Capacity utilization rate of each sampling point And it is sent to the local renewable energy RES via the communication network for subsequent calculation of utilization deviation, where The number representing all neighboring nodes of the renewable energy RES.

[0070] Step 4: Calculate the capacity utilization rate by collecting information on local capacity utilization and neighboring capacity utilization. Utilization deviation of each sampling point The specific calculation is shown in the following formula:

[0071]

[0072] In the formula: Indicates utilization deviation; Indicates the first Local capacity utilization rate of each sampling point; The first Capacity utilization rate of each sampling point; Indicates the first The renewable energy RES and the first The weight of the communication link between renewable energy sources (RES) is a positive number, with a default value of 1.

[0073] Step 5: The parameters obtained in Steps 1 and 4 are used to generate the local voltage reference value for the renewable energy source RES. The specific calculation is as follows:

[0074]

[0075] In the formula: Indicates the first Local voltage reference values ​​at each sampling point; Indicates the first The local bus voltage at each sampling point; Indicates utilization deviation; Indicates the first Local power generation capacity at each sampling point; For control parameters, use positive values.

[0076] It should be noted that, for DC power systems with constant current loads (CCLs), the control parameters in this embodiment... The range of values ​​for is:

[0077]

[0078] In the formula: This represents the minimum capacity of all renewable energy sources (RES). The largest eigenvalue of the Laplacian matrix of the communication network; It is the largest eigenvalue of the admittance matrix of the electrical network.

[0079] The range of values ​​for the control parameters described above in this embodiment is an important basis for ensuring the stable operation of a DC power system with a constant current load (CCL).

[0080] The method proposed in this embodiment is applicable to DC power systems of different voltage levels, and its equivalent bus voltage should not be higher than 1.2 times the nominal value.

[0081] The sampling period introduced in this embodiment can be selected according to actual requirements. When a larger sampling period is selected, the communication requirements of the system on the communication network will be reduced, but the ability of the proposed method to quickly adjust to load changes will also be reduced. When a smaller sampling period is selected, the communication requirements of the system on the communication network will increase, but the real-time response of the proposed method to load changes will be improved.

[0082] See Figure 5 The method and Figure 1 The diagram shows a comparison of the output power of existing technologies in DC power systems, where... Figure 5 This includes continuous-time power allocation methods, power allocation methods for a single common bus, and the method described in this invention. As shown in the figure: from 0 to 1 second, the constant current load CCL is 0; from 1 to 3 seconds, the constant current load CCL increases; from 0 to 2 seconds, the power generation capacity of the four renewable energy RES is 0.1, 0.2, 0.3, and 0.4, respectively; from 2 to 3 seconds, the power generation capacity of the four renewable energy RES is 0.25.

[0083] from Figure 5 It can be seen that under the continuous-time power distribution method, the DC power system oscillates when the constant current load CCL increases, threatening the safe operation of the system; from Figure 5 It can be seen that under the power allocation method oriented towards a single bus, the output power of each renewable energy RES cannot be accurately allocated according to its generating capacity. In particular, the output power of renewable energy RES 1 and renewable energy RES 2 exceeds their generating capacity, which can easily cause equipment damage. Figure 5 It can be seen that, under the dynamic power allocation method proposed in this invention, the output power of renewable energy RES can be accurately allocated according to its power generation capacity, and the oscillation problem of continuous time method is avoided.

[0084] Based on the same inventive concept, this embodiment of the invention also provides a distributed discrete dynamic power allocation system for constant current loads. Since the principle of solving the problem in this distributed discrete dynamic power allocation system for constant current loads is similar to that of the aforementioned distributed discrete dynamic power allocation method for constant current loads, the implementation of this distributed discrete dynamic power allocation system for constant current loads can refer to the implementation of the distributed discrete dynamic power allocation method for constant current loads, and the repeated parts will not be described again.

[0085] In specific implementation, the distributed discrete dynamic power allocation system for constant current loads provided in this embodiment of the invention specifically includes:

[0086] The first acquisition module is used to acquire the local output power and local power generation capacity of the renewable energy RES at each discrete sampling time.

[0087] The first calculation module is used to calculate the local capacity utilization rate based on the local output power and local power generation capacity.

[0088] The second acquisition module is used to acquire the neighbor capacity utilization rate of renewable energy RES;

[0089] The second calculation module calculates the utilization deviation based on the local capacity utilization rate and the neighbor's capacity utilization rate;

[0090] The adjustment module is used to generate a local voltage reference value for renewable energy sources (RES) based on the utilization deviation, and to dynamically adjust the power allocation based on the local voltage reference value.

[0091] Accordingly, embodiments of the present invention also provide a distributed discrete dynamic power allocation device for constant current loads, including a processor and a memory, wherein the processor executes a computer program stored in the memory to implement the distributed discrete dynamic power allocation method for constant current loads as provided in embodiments of the present invention.

[0092] For more detailed information on the above methods, please refer to the relevant content disclosed in the foregoing embodiments, which will not be repeated here.

[0093] Accordingly, embodiments of the present invention also provide a computer-readable storage medium for storing a computer program, wherein the computer program, when executed by a processor, implements the distributed discrete dynamic power allocation method for constant current loads as described above in embodiments of the present invention.

[0094] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems, devices, and storage media disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0095] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0096] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0097] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0098] The above provides a detailed description of the distributed discrete dynamic power allocation method, system, device, and storage medium for constant current loads provided by this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A distributed discrete dynamic power allocation method for constant current loads, characterized in that, For DC power systems containing N renewable energy sources RES, the following steps are included: S1. Obtain the local output power and local power generation capacity of renewable energy RES at each discrete sampling time; S2. Calculate the local capacity utilization rate based on the local output power and local power generation capacity; S3, Obtain the neighbor's capacity utilization rate for renewable energy sources RES; S4. Calculate the utilization rate deviation based on the local capacity utilization rate and the neighbor's capacity utilization rate; S5. Generate a local voltage reference value for renewable energy RES based on the utilization rate deviation, and dynamically adjust the power allocation based on the local voltage reference value. The local voltage reference value is calculated as follows: In the formula: Indicates the first Local voltage reference values ​​at each sampling point; Indicates the first The local bus voltage at each sampling point; Indicates utilization deviation; Indicates the first Local power generation capacity at each sampling point; For control parameters, use positive values; Input the local voltage reference value to the adjustment output of the renewable energy RES controller for dynamic power allocation; The range of values ​​for the control parameters is as follows: In the formula: This represents the minimum capacity of all renewable energy sources (RES). The largest eigenvalue of the Laplacian matrix of the communication network; It is the largest eigenvalue of the admittance matrix of the electrical network.

2. The distributed discrete dynamic power allocation method for constant current loads according to claim 1, characterized in that, The process of S1 is as follows: Obtain the first discrete sampling time. Output current and bus voltage of each renewable energy RES; The local output power is calculated based on the output current and bus voltage.

3. The distributed discrete dynamic power allocation method for constant current loads according to claim 1, characterized in that, The expression for the local capacity utilization rate in S2 is as follows: In the formula: Indicates the first Local capacity utilization rate of each sampling point; Indicates the first Local power generation capacity at each sampling point; Indicates the first The local output power of each sampling point.

4. The distributed discrete dynamic power allocation method for constant current loads according to claim 1, characterized in that, The neighbor capacity utilization rate includes: The capacity utilization rate of the neighbors of the renewable energy source RES at the discrete sampling time is obtained using a communication network.

5. The distributed discrete dynamic power allocation method for constant current loads according to claim 1, characterized in that, The S4 process is as follows: The utilization rate deviation is calculated as shown in the following formula: In the formula: Indicates utilization deviation; Indicates the first Local capacity utilization rate of each sampling point; The first Capacity utilization rate of each sampling point; Indicates the first The renewable energy RES and the first The weight of the communication link between renewable energy sources (RES) is 1 by default.

6. A distributed discrete dynamic power distribution system for constant current loads, characterized in that, include: The first acquisition module is used to acquire the local output power and local power generation capacity of the renewable energy RES at each discrete sampling time. The first calculation module is used to calculate the local capacity utilization rate based on the local output power and local power generation capacity. The second acquisition module is used to acquire the neighbor capacity utilization rate of renewable energy RES; The second calculation module calculates the utilization deviation based on the local capacity utilization rate and the neighbor's capacity utilization rate; The adjustment module is used to generate a local voltage reference value for renewable energy RES based on the utilization deviation, and to dynamically adjust the power allocation based on the local voltage reference value. The local voltage reference value is calculated as follows: In the formula: Indicates the first Local voltage reference values ​​at each sampling point; Indicates the first The local bus voltage at each sampling point; Indicates utilization deviation; Indicates the first Local power generation capacity at each sampling point; For control parameters, use positive values; Input the local voltage reference value to the adjustment output of the renewable energy RES controller for dynamic power allocation; The range of values ​​for the control parameters is as follows: In the formula: This represents the minimum capacity of all renewable energy sources (RES). The largest eigenvalue of the Laplacian matrix of the communication network; It is the largest eigenvalue of the admittance matrix of the electrical network.

7. A distributed discrete dynamic power distribution device for constant current loads, characterized in that, It includes a processor and a memory, wherein the processor executes a computer program stored in the memory to implement the distributed discrete dynamic power allocation method for constant current loads as described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, Used to store a computer program, wherein the computer program, when executed by a processor, implements the distributed discrete dynamic power allocation method for constant current loads as described in any one of claims 1 to 5.

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