A method and system for limiting power distribution

Abstract

This invention relates to the field of new energy power generation and energy storage, and in particular to a method and system for limiting power distribution, comprising: setting a total power distribution capacity limit value, wherein the total power distribution capacity limit value is an unsigned value representing the maximum absolute value of power allowed at the grid connection point; calculating in real time the total active power at the connection point between the new energy grid-connected equipment and the power distribution facilities; dynamically calculating the power output limit value of the new energy grid-connected equipment based on the total power distribution capacity limit value and the total active power through a closed-loop control algorithm, wherein the power output limit value includes a positive power limit value and a negative power limit value; and controlling the output power of the new energy grid-connected equipment using the positive power limit value and the negative power limit value as boundaries. This invention, through detailed parameter settings, signal processing, algorithm calculation, and hardware control procedures, fully realizes bidirectional power distribution limitation, effectively protecting the safety of user-side power distribution facilities.

Description

Technical Field

[0001] This invention relates to the field of new energy power generation and energy storage, and in particular to a method and system for limiting power distribution. Background Technology

[0002] In grid-connected systems of new energy sources such as photovoltaics and energy storage, when equipment such as energy storage converters (PCS) are connected to the grid, the rated capacity of cables, distribution transformers and circuit breakers (hereinafter referred to as "circuit breakers") in the user-side power distribution network is limited. Therefore, the total bidirectional power flow between the grid connection point and the power distribution facilities must be strictly limited to ensure that it does not exceed the safety threshold. Otherwise, it will lead to overload and burnout of the power distribution facilities or protective tripping, which will in turn cause local power distribution safety accidents. This is the core requirement of local power distribution safety management.

[0003] Currently, various power control functions exist in the field of renewable energy grid connection, but their design goals cannot cover local power distribution safety management scenarios. Among them, the core purpose of the anti-islanding (or zero power grid-feed) function is to respond to grid operation specifications and block reverse power feed into distribution facilities. It is mostly used in scenarios without grid-connected electricity price subsidies or where grid capacity is limited. Its power limit threshold is usually fixed at zero or a very small value and only applies to reverse feed power, failing to effectively manage overload problems in distribution facilities caused by excessive forward power transmission from the grid (i.e., local power consumption). Energy management functions, typically represented by time-of-use pricing-based charging and discharging strategies, aim to optimize the economic operation of renewable energy systems by reducing electricity costs through charging and discharging scheduling during price fluctuation cycles. However, they do not establish a power limit mechanism specifically for the safety of local power distribution facilities.

[0004] In summary, existing technologies lack power control schemes with the core objective of protecting user-side power distribution facilities. In particular, they lack flexible, symmetrical, and customizable threshold limiting control methods for bidirectional power at the grid connection point. When power distribution facilities charge PCS and other equipment or supply power to local loads, if the forward power exceeds the rated capacity of the power distribution facilities, it will cause faults such as tripping of circuit breakers on the grid side or burning of cables. Existing control functions cannot cover this scenario, forming a technological gap. Summary of the Invention

[0005] Therefore, the technical problem to be solved by this invention is that when grid-connected equipment such as power storage converters (PCS) in new energy systems such as photovoltaic energy storage are connected to the grid, the existing technology lacks a limiting control method that focuses on protecting the user-side power distribution facilities, can flexibly and symmetrically limit the bidirectional power at the grid connection point, and allows for customizable thresholds. This leads to the technical problem that the power distribution facilities are prone to overload burnout or tripping due to excessive forward power intake or reverse power feedback. Therefore, this invention provides a power distribution limiting method and system, wherein the power distribution limiting method includes the following steps:

[0006] S1: Set the total unsigned power distribution capacity limit;

[0007] S2: Real-time monitoring of the total active power at the connection point between the new energy grid-connected equipment and the power distribution facilities; based on the total power distribution capacity limit and the total active power, dynamically calculating the maximum positive power output limit and the maximum negative power output limit that the grid-connected equipment is allowed to execute at the current moment through a closed-loop control algorithm;

[0008] S3: Control the actual output power of the grid-connected equipment to limit it within the range determined by the maximum positive power output limit and the maximum negative power output limit.

[0009] In one embodiment of the present invention, in step S2, when the new energy grid-connected equipment is operating in a single-phase system or a three-phase balanced system, the method for dynamically calculating the maximum positive power output limit and the maximum negative power output limit allowed for the grid-connected equipment at the current moment through a closed-loop control algorithm is as follows:

[0010] A first control loop and a second control loop are configured in parallel. The first control loop is used to limit the power drawn by the new energy grid-connected equipment from the power distribution facility to obtain a positive power limit value, including:

[0011] Calculate the first power error signal , The total active power collected. This is the total power distribution capacity limit.

[0012] The first power error signal The input is fed into a preset first proportional-integral controller, which calculates the first power correction amount using the following formula. :

[0013] , , The pre-set proportional and integral coefficients;

[0014] Based on the first power correction amount Calculate the maximum forward power output limit allowed to be executed at the current moment. :

[0015] , This refers to the inherent maximum positive power of the new energy grid-connected equipment, i.e., the positive value of its rated power;

[0016] The second control loop is used to limit the power fed to the grid by the new energy grid-connected equipment to obtain a negative power limit value, including:

[0017] Calculate the second power error signal , The total active power collected. This is the total power distribution capacity limit.

[0018] The second power error signal The input is fed into a preset second proportional-integral controller, which calculates the second power correction amount using the following formula. :

[0019] , , The pre-set proportional and integral coefficients;

[0020] Based on the second power correction amount Calculate the maximum negative power output limit allowed at the current moment. :

[0021] , This refers to the inherent maximum negative power of the new energy grid-connected equipment, which is the negative value of its rated power.

[0022] In one embodiment of the present invention, in step S2, when the new energy grid-connected equipment is operating in an N-phase unbalanced system, the method for dynamically calculating the maximum positive power output limit and the maximum negative power output limit allowed for the grid-connected equipment at the current moment through a closed-loop control algorithm is as follows:

[0023] The total power distribution capacity limit is allocated to each phase according to a preset rule to obtain the power limit value for each phase. Calculate the real-time active power of each phase. X represents a phase;

[0024] For each phase, a first control loop and a second control loop are set up in parallel. The first control loop is used to limit the power drawn from the power distribution facility by that phase in the new energy grid-connected equipment to obtain a positive power limit value, including:

[0025] Calculate the forward power error signal for each phase. ;

[0026] The positive power error signal The input is fed into a preset third proportional-integral controller, which calculates the first power correction amount using the following formula. :

[0027] , , The pre-set proportional and integral coefficients;

[0028] Based on the first power correction amount Calculate the maximum forward power output limit allowed to be executed at the current moment. :

[0029] , This represents the initial value of the maximum allowable positive power for grid-connected new energy equipment on phase X.

[0030] The second control loop is used to limit the power fed to the grid by the new energy grid-connected equipment to obtain a negative power limit value, including:

[0031] Calculate the negative power error signal for each term. ;

[0032] The negative power error signal The input is fed into a preset second proportional-integral controller, which calculates the negative power correction amount using the following formula. :

[0033] , , The pre-set proportional and integral coefficients;

[0034] Based on the negative power correction amount Calculate the maximum negative power output limit allowed at the current moment. :

[0035] , This represents the initial value of the maximum allowable negative power for grid-connected new energy equipment on phase X.

[0036] In one embodiment of the present invention, the method for controlling the actual output power of the grid-connected device in step S3 to limit it within the range determined by the maximum positive power output limit and the maximum negative power output limit is as follows:

[0037] The limiting range constituted by the power output limit value of each phase. Current / power control loop acting on the corresponding phase;

[0038] Each phase's control loop uses its own dynamic limit as a boundary to generate a PWM drive signal for that phase. The PWM signal of each phase drives its corresponding power switching device arm, thus controlling the active power of each phase. Controlled Within the power limit range.

[0039] In one embodiment of the present invention, the total power distribution capacity limit is allocated to each phase according to a preset rule to obtain the power limit value for each phase. The methods include:

[0040] The set unsigned total power distribution capacity limit is evenly distributed to each phase as the power limit allocation value for each phase.

[0041] In one embodiment of the present invention, the total power distribution capacity limit is determined based on the rated capacity of the circuit breakers, power cables or transformers of the on-site power distribution facilities.

[0042] Based on the same inventive concept, the present invention also provides a power distribution limiting system, including: a human-machine interaction module, a data acquisition module, a control processing module, and a power module;

[0043] The human-computer interaction module is configured to receive and send the user-defined unsigned total power distribution capacity limit value.

[0044] The acquisition module is configured to: monitor the total active power at the connection point between the new energy grid-connected equipment and the power distribution facilities in real time;

[0045] The control processing module is communicatively connected to the human-machine interaction module and the acquisition module, and is configured to: dynamically generate real-time power output limit commands based on the total power distribution capacity limit value and the total active power through a closed-loop control algorithm;

[0046] The power module, connected to the control processing module, is configured to control the actual power output of the grid-connected equipment according to the power output limit command.

[0047] In one embodiment of the present invention, the system further includes a communication interface module, through which the control processing module communicates with the control processing module of at least one other grid-connected device to coordinate the power output limits of each device.

[0048] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the power distribution limiting method when executing the program.

[0049] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the power distribution limiting method.

[0050] Compared with the prior art, the above-described technical solution of the present invention has the following advantages:

[0051] This invention proposes a power control method specifically for protecting user-side power distribution facilities, which is fundamentally different from existing functions such as anti-reverse current. Based on unsigned distribution capacity values, it achieves bidirectional symmetrical flexible power limiting at the grid connection point, preventing both excessive power feed to the grid and excessive power draw from the grid, thus comprehensively ensuring power distribution safety. Users can flexibly set the power limit value GridLimit according to the actual capacity of the on-site power distribution facilities, making it highly practical. Through pattern recognition and phase-by-phase control, it is compatible with various system modes such as single-phase, three-phase balanced, and three-phase unbalanced, offering wide versatility. Simultaneously, it employs a closed-loop PI control algorithm, which can quickly and smoothly respond to power fluctuations, stabilizing the grid power near the set limit, avoiding system oscillations, and combining dynamic responsiveness with stability. Attached Figure Description

[0052] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0053] Figure 1 This is a schematic flowchart of a power distribution limiting method provided in an embodiment of the present invention;

[0054] Figure 2 This is a schematic diagram of the structure of a power distribution limiting system provided in an embodiment of the present invention;

[0055] Figure 3 This is a connection diagram of the communication interface module provided in an embodiment of the present invention.

[0056] Explanation of reference numerals in the accompanying drawings: 100, Human-Machine Interaction Module; 200, Data Acquisition Module; 300, Control Processing Module; 400, Power Module; 500, Communication Interface Module. Detailed Implementation

[0057] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0058] Example 1:

[0059] Reference Figure 1 As shown, this invention provides a power distribution limiting method to protect local power distribution facilities by symmetrically limiting bidirectional power at power distribution network connection points. The method specifically includes the following steps:

[0060] S1: Set the total unsigned power distribution capacity limit;

[0061] S2: Calculate the total active power at the connection point between the new energy grid-connected equipment and the power distribution facility in real time. Based on the total power distribution capacity limit and the total active power, dynamically calculate the maximum positive power output limit and the maximum negative power output limit that the grid-connected equipment is allowed to execute at the current moment through a closed-loop control algorithm.

[0062] S3: Control the actual output power of the grid-connected equipment to limit it within the range determined by the maximum positive power output limit and the maximum negative power output limit.

[0063] Furthermore, in step S1, an unsigned total power distribution capacity limit value is set. The method is as follows:

[0064] Based on the rated capacity parameters of the on-site power distribution facilities (including distribution air switches, cables, and transformers), configure a dimensionless total power distribution capacity limit value. This value represents the absolute maximum power allowed at the grid connection point, corresponding to a bidirectional power allowable range of [value missing]. ,in This refers to the maximum power threshold that grid-connected equipment can draw from the power grid. This is the maximum power threshold for grid-connected equipment to feed power to the grid.

[0065] For example, if the rated capacity of the on-site power distribution circuit breaker is 50kW, then set The value is 50, and the permissible bidirectional power range at the corresponding grid connection point is [-50kW, +50kW], where +50kW is the maximum power threshold for new energy grid-connected equipment to draw power from the distribution facility, and -50kW is the maximum power threshold for new energy grid-connected equipment to feed power to the distribution facility. The total distribution power capacity limit value is... After the parameters are verified to be valid, they are sent to the main control chip of the new energy grid-connected equipment through a preset communication link and stored in a designated register inside the chip as the reference parameters for subsequent power limit calculations.

[0066] In step S2, the control chip is based on the and real-time active power The maximum forward power output limit of grid-connected equipment is dynamically calculated using a closed-loop PI control algorithm. ) and maximum negative power output limit ( Depending on the system's operating mode (balanced mode, unbalanced mode), the calculation method is as follows:

[0067] When the new energy grid-connected equipment operates in a single-phase or three-phase balanced system, the method for dynamically calculating the power output limit value of the new energy grid-connected equipment through a closed-loop control algorithm is as follows:

[0068] A first control loop and a second control loop are configured in parallel. The first control loop is used to limit the power drawn by the new energy grid-connected equipment from the power distribution facility, ensuring that it does not exceed the limit set by the grid-connected equipment. The positive power limit value is obtained. ,include:

[0069] Calculate the first power error signal , The total active power collected;

[0070] The first power error signal The input is fed into a preset first proportional-integral controller, which calculates the first power correction amount using the following formula. :

[0071] , , The pre-set proportional and integral coefficients;

[0072] Based on the first power correction amount Calculate the maximum forward power output limit allowed to be executed at the current moment. :

[0073] , This refers to the inherent maximum positive power of the new energy grid-connected equipment, i.e., the positive value of its rated power; when At that time, the first power error signal If positive, the first power correction amount This makes the maximum positive power output limit This reduces the amount of power that grid-connected equipment draws from the grid.

[0074] The second control loop is used to limit the power fed into the grid by the new energy grid-connected equipment, so that it does not exceed the limit. The negative power limit value is obtained. ,include:

[0075] Calculate the second power error signal , The total active power collected;

[0076] The second power error signal The input is fed into a preset second proportional-integral controller, which calculates the second power correction amount using the following formula. :

[0077] , , The pre-set proportional and integral coefficients;

[0078] Based on the second power correction amount Calculate the current allowed negative power limit value. :

[0079] , This refers to the inherent maximum negative power of the new energy grid-connected equipment, i.e., the negative value of its rated power. When At that time, the second power error signal If it is negative, the second power correction amount This makes the negative power limit value Increase the power output of grid-connected equipment, bringing it closer to zero, thereby reducing the power fed into the grid.

[0080] When the new energy grid-connected equipment operates in an N-phase unbalanced system, the method for dynamically calculating the power output limit value of the new energy grid-connected equipment through a closed-loop control algorithm is as follows:

[0081] Set the unsigned total power distribution capacity limit value. The power limit is evenly distributed to each phase as the power limit allocation value for each phase. N is the number of phases, and the real-time active power of each phase is calculated. X represents a phase;

[0082] For each phase, a first control loop and a second control loop are set up in parallel. The first control loop is used to limit the power drawn from the power distribution facility by that phase in the new energy grid-connected equipment to obtain a positive power limit value, including:

[0083] Calculate the forward power error signal for each phase. ;

[0084] The positive power error signal The input is fed into a preset third proportional-integral controller, which calculates the first power correction amount using the following formula. :

[0085] , , The pre-set proportional and integral coefficients;

[0086] Based on the first power correction amount Calculate the maximum forward power output limit allowed to be executed at the current moment. :

[0087] , This represents the initial value of the maximum allowable positive power for grid-connected new energy equipment on phase X.

[0088] The second control loop is used to limit the power fed to the grid by the new energy grid-connected equipment to obtain a negative power limit value, including:

[0089] Calculate the negative power error signal for each term. ;

[0090] The negative power error signal The input is fed into a preset second proportional-integral controller, which calculates the negative power correction amount using the following formula. :

[0091] , , The pre-set proportional and integral coefficients;

[0092] Based on the negative power correction amount Calculate the maximum negative power output limit allowed at the current moment. :

[0093] , This represents the initial value of the maximum allowable negative power for grid-connected new energy equipment on phase X.

[0094] Furthermore, in S3, the method for controlling the actual output power of the grid-connected equipment to be limited to the range determined by the maximum positive power output limit and the maximum negative power output limit is as follows:

[0095] The limiting range constituted by the power output limit value of each phase. (In balanced mode, X represents the entire system; in unbalanced mode, X represents each phase) The current / power control loop acting on the corresponding phase;

[0096] Each phase's control loop is bounded by its own dynamic limit. Based on real-time power demand, it calculates and generates a PWM drive signal for that phase. The PWM signal of each phase drives its corresponding power switching device arm, adjusting the output power of the grid-connected equipment, ultimately controlling the active power of each phase. Strictly controlled at Within the power limit, ensure the total active power of the system. In The safe zone.

[0097] This embodiment achieves the following technical effects through the above steps: First, bidirectional symmetrical limiting: It simultaneously limits the power taken from and fed into the grid, preventing overload of distribution facilities due to unidirectional power exceeding limits, and solving the defect of existing anti-reverse current functions that only limit the power fed into the grid. Second, flexible and adjustable: Users can customize GridLimit according to the actual capacity of the distribution facilities to adapt to different scenario requirements. Third, strong versatility: It is compatible with single-phase, three-phase balanced, and three-phase unbalanced systems, and is suitable for various new energy grid-connected equipment. Fourth, dynamic stability: It adopts a closed-loop PI control algorithm to quickly respond to power fluctuations, stabilizing the grid power near the set limit and avoiding system oscillations.

[0098] Example 2:

[0099] like Figure 2 As shown, based on the same inventive concept as Embodiment 1, the present invention also provides a power distribution limiting system, configured in a grid-connected device, specifically including: a human-machine interaction module 100, a data acquisition module 200, a control processing module 300, and a power module 400; the power distribution facilities consist of a public power grid, transformers, distribution circuit breakers, and distribution cables, and its rated capacity is the system power limiting value. The basis for judgment;

[0100] The human-computer interaction module 100 includes host computer software, a mobile terminal APP, and a device local display and button unit, and is configured to receive the user-set unsigned total power distribution capacity limit value. And complete the distribution, while realizing real-time display of system operation data and interactive operation of working conditions;

[0101] The acquisition module 200 consists of a voltage sensor, a current sensor (such as a Hall sensor), and a sampling and conditioning circuit. It is used to acquire, in real time, the analog voltage and analog current signals at the AC connection point of the new energy grid-connected equipment or the grid side and transmit them to the control and processing module 300. Some integrated devices can directly calculate and output the instantaneous total active power through built-in algorithms. To achieve real-time monitoring of the total active power at the connection point between new energy grid-connected equipment and the public power grid;

[0102] The control processing module 300 uses a digital signal processor (DSP), microcontroller unit (MCU), or microprocessor (MPU) as its hardware carrier, and is communicatively connected to the human-machine interaction module 100 and the acquisition module 200. It is configured to receive the total power distribution capacity limit value issued by the human-machine interaction module 100. The data includes raw voltage and current data transmitted by the acquisition module 200 or the total active power directly output. After data filtering and conversion processing, a closed-loop control algorithm is executed, which is the same principle as in Example 1, dynamically generating real-time power output limit commands, i.e., positive power limit values ​​( ) and reverse power limit ( );

[0103] The power module 400 consists of power switching devices (such as insulated-gate bipolar transistors (IGBTs) and metal-oxide-semiconductor field-effect transistors (MOSFETs)) and their driving circuits. It is connected to the control processing module 300 and configured to receive power or current commands from the control processing module 300, and to apply positive power limiting values. and reverse power limit value As a power output boundary constraint, a high-frequency PWM drive pulse signal is generated to drive the power switching device to switch on and off, thereby controlling the actual power output of the grid-connected equipment and realizing bidirectional power regulation.

[0104] Furthermore, in a preferred embodiment of the present invention, as... Figure 3 As shown, the system also includes a communication interface module 500. The control processing module 300 communicates with the control processing module 300 of at least one other grid-connected device through the communication interface module 500 to coordinate the power output limits of each grid-connected device and ensure the stable operation of the power distribution system.

[0105] Example 3:

[0106] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the power distribution limiting method as described in Embodiment 1.

[0107] Example 4:

[0108] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the power distribution limiting method described in Embodiment 1.

[0109] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application 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.

[0110] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0111] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0112] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0113] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A power distribution power limiting method, characterized by, include: S1: Set the total unsigned power distribution capacity limit; S2: Real-time monitoring of the total active power at the connection point between the new energy grid-connected equipment and the power distribution facilities; based on the total power distribution capacity limit and the total active power, dynamically calculating the maximum positive power output limit and the maximum negative power output limit that the grid-connected equipment is allowed to execute at the current moment through a closed-loop control algorithm; S3: Control the actual output power of the grid-connected equipment to limit it within the range determined by the maximum positive power output limit and the maximum negative power output limit; In step S2, when the new energy grid-connected equipment is operating in a single-phase system or a three-phase balanced system, the method for dynamically calculating the maximum positive power output limit and the maximum negative power output limit allowed for the grid-connected equipment at the current moment through a closed-loop control algorithm is as follows: A first control loop and a second control loop are configured in parallel. The first control loop is used to limit the power drawn by the new energy grid-connected equipment from the power distribution facility to obtain a positive power limit value, including: calculating a first power error signal , for the total active power collected, for the total power distribution capacity limit value; The first power error signal is input to a preset first proportional-integral controller, and the first proportional-integral controller calculates a first power correction amount by the following equation : , , The pre-set proportional and integral coefficients; Based on the first power correction amount Calculate the maximum forward power output limit allowed to be executed at the current moment. : , This refers to the inherent maximum positive power of the new energy grid-connected equipment, i.e., the positive value of its rated power; The second control loop is used to limit the power fed to the grid by the new energy grid-connected equipment to obtain a negative power limit value, including: Calculate the second power error signal , The total active power collected. This is the total power distribution capacity limit. The second power error signal The input is fed into a preset second proportional-integral controller, which calculates the second power correction amount using the following formula. : , , The pre-set proportional and integral coefficients; Based on the second power correction amount Calculate the maximum negative power output limit allowed at the current moment. : , This refers to the inherent maximum negative power of the new energy grid-connected equipment, which is the negative value of its rated power.

2. A method for limiting power distribution, characterized in that, include: S1: Set the total unsigned power distribution capacity limit; S2: Real-time monitoring of the total active power at the connection point between the new energy grid-connected equipment and the power distribution facilities; based on the total power distribution capacity limit and the total active power, dynamically calculating the maximum positive power output limit and the maximum negative power output limit that the grid-connected equipment is allowed to execute at the current moment through a closed-loop control algorithm; S3: Control the actual output power of the grid-connected equipment to limit it within the range determined by the maximum positive power output limit and the maximum negative power output limit; In step S2, when the new energy grid-connected equipment is operating in an N-phase unbalanced system, the method for dynamically calculating the maximum positive power output limit and the maximum negative power output limit allowed for the grid-connected equipment at the current moment through a closed-loop control algorithm is as follows: The total power distribution capacity limit is allocated to each phase according to a preset rule to obtain the power limit value for each phase. Calculate the real-time active power of each phase. X represents a phase; For each phase, a first control loop and a second control loop are set up in parallel. The first control loop is used to limit the power drawn from the power distribution facility by that phase in the new energy grid-connected equipment to obtain a positive power limit value, including: Calculate the forward power error signal for each phase. ; The positive power error signal The input is fed into a preset third proportional-integral controller, which calculates the first power correction amount using the following formula. : , , The pre-set proportional and integral coefficients; Based on the first power correction amount Calculate the maximum forward power output limit allowed to be executed at the current moment. : , This represents the initial value of the maximum allowable positive power for grid-connected new energy equipment on phase X. The second control loop is used to limit the power fed to the grid by the new energy grid-connected equipment to obtain a negative power limit value, including: Calculate the negative power error signal for each term. ; The negative power error signal The input is fed into a preset second proportional-integral controller, which calculates the negative power correction amount using the following formula. : , , The pre-set proportional and integral coefficients; Based on the negative power correction amount Calculate the maximum negative power output limit allowed at the current moment. : ， This represents the initial value of the maximum allowable negative power for grid-connected new energy equipment on phase X.

3. The power distribution limiting method according to claim 2, characterized in that, In step S3, the method for controlling the actual output power of the grid-connected equipment to be limited within the range determined by the maximum positive power output limit and the maximum negative power output limit is as follows: The limiting range constituted by the power output limit value of each phase. Current / power control loop acting on the corresponding phase; Each phase's control loop uses its own dynamic limit as a boundary to generate a PWM drive signal for that phase. The PWM signal of each phase drives its corresponding power switching device arm, thus controlling the active power of each phase. Controlled Within the power limit range.

4. The power distribution limiting method according to claim 2, characterized in that, The total power distribution capacity limit is allocated to each phase according to a preset rule to obtain the power limit value for each phase. The methods include: The set unsigned total power distribution capacity limit is evenly distributed to each phase as the power limit allocation value for each phase.

5. The power distribution limiting method according to claim 1 or 2, characterized in that, The total power distribution capacity limit is determined based on the rated capacity of the circuit breakers, cables, or transformers in the on-site power distribution facilities.

6. A power distribution limiting system, characterized in that, To implement the power distribution limiting method as described in any one of claims 1 to 5, comprising: The human-computer interaction module is configured to receive and send the user-defined unsigned total power distribution capacity limit value; The data acquisition module is configured to monitor the total active power at the connection point between the new energy grid-connected equipment and the power distribution facilities in real time. The control processing module, communicatively connected to the human-machine interface module and the data acquisition module, is configured to: dynamically generate real-time power output limit commands based on the total power distribution capacity limit and the total active power using a closed-loop control algorithm; and The power module, connected to the control processing module, is configured to control the actual power output of the grid-connected equipment according to the power output limit command.

7. The power distribution limiting system according to claim 6, characterized in that, It also includes a communication interface module, through which the control processing module communicates with the control processing module of at least one other grid-connected device to coordinate the power output limits of each device.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the power distribution limiting method as described in any one of claims 1 to 5.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the power distribution limiting method as described in any one of claims 1 to 5.

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