Methods, systems, equipment, and media for power line flow control in power systems

Abstract

This invention relates to the field of power system technology and discloses a method, system, equipment, and medium for line power flow regulation in power systems. The method involves collecting operational data of the power system after the integration of renewable energy equipment to predict the target value of reactive power demand. When this value falls within the regulation capacity range of reactive power flow regulation equipment, including bypass switches, LC filters, H-bridge converters, and DC capacitors, multiple target devices are determined based on the capacity margin of the equipment and its electrical distance from the renewable energy equipment. A quadratic programming model is constructed and solved based on the target value of reactive power demand to obtain the output strategy of the target devices, which is then sent to the corresponding target devices to control the line power flow through decoupling control technology. The regulation results are verified; if the verification fails, the target value of reactive power demand is incrementally corrected, and the strategy is re-solved until the final verification is successful, thereby achieving effective regulation of line power flow in the power system.

Description

Technical Field

[0001] This invention relates to the field of power system technology, and in particular to a method, system, device and medium for line power flow control in power systems. Background Technology

[0002] In existing technologies, the control methods of traditional reactive power compensation equipment, such as capacitors and reactors, are relatively simple and independent. They are usually switched on and off based on fixed setpoints or simple local measurement signals. They lack the ability to perceive and coordinate the global information of the entire power system. This makes it difficult for the adjustment of various devices to coordinate in complex power grid environments, which can easily lead to overcompensation or undercompensation. They cannot accurately meet the dynamic needs of the power system as new energy generation becomes intermittent and fluctuating, thus affecting the stable operation of the power grid and power quality.

[0003] Therefore, how to regulate the power flow in the power system to adapt to the changes in reactive power demand caused by the access of new energy sources has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] This invention provides a method, system, device, and medium for line power flow regulation in power systems, addressing the problem of how to regulate line power flow in power systems to adapt the system to changes in reactive power demand caused by the integration of new energy sources into the power grid.

[0005] To solve the above-mentioned technical problems, the first aspect of the present invention provides a method for line power flow control in a power system, comprising:

[0006] Real-time acquisition of power system operation data after the connection of new energy equipment, and prediction of the target value of reactive power demand of the power system in a future preset period based on the operation data;

[0007] When the reactive power demand target value is within the adjustment capacity constraint range of the reactive power flow control equipment, multiple target devices are determined based on the capacity margin of the reactive power flow control equipment and its electrical distance from the new energy equipment; the reactive power flow control equipment includes a bypass switch, an LC filter, an H-bridge converter, and a DC capacitor;

[0008] Based on the target value of reactive power demand, a quadratic programming model is constructed and solved to obtain the output strategy of the target equipment and send it to the corresponding target equipment so as to control each target equipment to regulate the power flow of the line through decoupling control technology.

[0009] Obtain the actual power data of the power system after power flow regulation through each of the target equipment lines, and calculate the deviation between the actual power data and the reactive power demand target value;

[0010] When the deviation exceeds a preset deviation threshold, the reactive power demand target value is incrementally corrected, and the target equipment output strategy generation process is iteratively executed based on the corrected reactive power demand target value until the final actual power data does not exceed the preset deviation threshold, so as to achieve the regulation of line power flow in the power system.

[0011] A second aspect of the present invention provides a line power flow control system for a power system, comprising:

[0012] The target prediction module is used to collect real-time operating data of the power system after the connection of new energy equipment, and predict the target value of reactive power demand of the power system in a future preset period based on the operating data.

[0013] The equipment selection module is used to determine multiple target devices based on the capacity margin of the reactive power flow control equipment and its electrical distance from the new energy equipment when the reactive power demand target value is within the adjustment capacity constraint range of the reactive power flow control equipment; the reactive power flow control equipment includes a bypass switch, an LC filter, an H-bridge converter, and a DC capacitor;

[0014] The power flow control module is used to construct and solve a quadratic programming model based on the reactive power demand target value, obtain the output strategy of the target equipment, and send it to the corresponding target equipment to control the power flow of the line through decoupling control technology.

[0015] The deviation calculation module is used to obtain the actual power data of the power system after power flow regulation through each of the target equipment lines, and to calculate the deviation between the actual power data and the reactive power demand target value.

[0016] The iterative control module is used to incrementally correct the reactive power demand target value when the deviation exceeds a preset deviation threshold, and iteratively execute the generation process of the target equipment output strategy according to the corrected reactive power demand target value until the final actual power data does not exceed the preset deviation threshold, so as to realize the control of the line power flow in the power system.

[0017] A third aspect of the present invention provides an electronic device including a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the line power flow control method for a power system as described above.

[0018] A fourth aspect of the present invention provides a computer-readable storage medium comprising a stored computer program, wherein when the device containing the computer-readable storage medium executes the computer program, it implements the line power flow control method for a power system as described above.

[0019] Compared with the prior art, the beneficial effects of the embodiments of the present invention are at least one of the following:

[0020] (1) By collecting and analyzing the operating data of the power system after the access of new energy equipment in real time, it is possible to accurately predict the target value of future reactive power demand and formulate reactive power flow control strategies accordingly. Furthermore, when formulating the strategies, the adjustment capacity constraints, capacity margins and electrical distances of the reactive power flow control equipment are comprehensively considered, ensuring the effectiveness and feasibility of the control strategies.

[0021] (2) Through decoupling control technology, each target device can independently and accurately regulate the power flow of the line, realize the coordinated output of multiple reactive power flow regulation devices, and improve the stability and operating efficiency of the power system. At the same time, the scheme also has self-correction capability, which can incrementally correct the reactive power demand target value according to the deviation between the actual power data and the reactive power demand target value, and iteratively execute the regulation strategy until the preset regulation accuracy is achieved, thereby realizing the precise regulation of the power flow of the line in the power system. Attached Figure Description

[0022] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a flowchart of a line power flow control method for a power system provided in a certain embodiment of the present invention;

[0024] Figure 2 This is a topology diagram of a reactive power flow control device provided in a certain embodiment of the present invention;

[0025] Figure 3 This is a main circuit diagram of a reactive power flow control device provided in a certain embodiment of the present invention;

[0026] Figure 4 This is an equivalent circuit diagram of a reactive power flow control device provided in a certain embodiment of the present invention;

[0027] Figure 5 This is a voltage outer loop control block diagram provided in a certain embodiment of the present invention;

[0028] Figure 6 This is a current inner loop control block diagram provided in a certain embodiment of the present invention;

[0029] Figure 7 This is a structural diagram of a line power flow control system for a power system provided in a certain embodiment of the present invention;

[0030] Figure 8 This is a structural diagram of an electronic device provided in a certain embodiment of the present invention;

[0031] Figure label:

[0032] Among them, 1. Reactive power flow control equipment; 2. Bypass switch; 3. LC filter; 4. H-bridge converter; 5. DC capacitor; 6. Inductor; 7. External access equipment; 8. Transformer; 10. Target prediction module; 20. Equipment selection module; 30. Power flow control module; 40. Deviation calculation module; 50. Iterative control module; 5000. Electronic equipment; 5001. Processor; 5002. Bus; 5003. Memory; 5004. Transceiver. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings and examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] In the description of this application, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0035] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. The terms "vertical," "horizontal," "left," "right," "upper," "lower," and similar expressions used herein are for illustrative purposes only and do not indicate or imply that the system or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0036] In the description of this application, it should be noted that, unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is merely for describing specific embodiments and is not intended to limit the invention. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0037] Currently, with the expansion of power system scale and the increasing complexity of loads, reactive power flow control faces numerous challenges. On the one hand, line impedance leads to large reactive power transmission losses, and differences in reactive power demand in different regions result in unreasonable power flow distribution, causing voltage fluctuations and limited active power transmission. On the other hand, traditional reactive power compensation equipment has a single adjustment method and slow response, and its switching is prone to inrush current, making it difficult to meet the requirements of rapid and accurate control. At the same time, the integration of new energy equipment causes frequent changes in the system's reactive power demand, which in turn affects the voltage stability and power quality of the power grid.

[0038] Based on this, in one embodiment, such as Figure 1 As shown, the first aspect of the present invention provides a method for line power flow control in a power system, comprising:

[0039] S1. Collect real-time operating data of the power system after the connection of new energy equipment, and predict the target value of reactive power demand of the power system in a future preset period based on the operating data;

[0040] In one embodiment, step S1 includes:

[0041] The power system's output power, line power flow data, and equipment operating status data are collected in real time after the new energy equipment is connected, and used as the operating data.

[0042] The operating data is processed using a sliding time window or a pre-trained long short-term memory network to predict the reactive power demand trend of the power system within a future preset time period, thereby obtaining the target value of reactive power demand.

[0043] Specifically, after the new energy equipment is connected to the power system via transmission lines, multiple reactive power flow control devices 1 are installed at the connection point between the new energy equipment and the system. It should be noted that the functions and structures of all reactive power flow control devices connected to the power system are the same, and they can all be referred to as reactive power flow control device 1. The topology of the reactive power flow control device 1 used in this invention is as follows: Figure 2 As shown, it includes a bypass switch 2, an LC filter 3, an H-bridge converter 4, and a DC capacitor 5. Multiple units are deployed in series in the power system. Considering all the reactive power flow control equipment 1 as a single unit—a series equipment group—the external access equipment 7 (i.e., loads and new energy equipment, such as wind turbines and photovoltaic units) is located at both ends of the series equipment group and connected to it via a transformer 8. An inductor 6 is also deployed at the input end of the series equipment group and connected to the output end of the external access equipment 7. The main circuit of the reactive power flow control equipment 1 is as follows: Figure 3 As shown, in Figure 3 middle, This refers to the voltage to ground at the left connection point; This refers to the voltage to ground at the right-side connection point; The equivalent internal resistance of the series connection side; , These are the filter inductance and DC capacitance values ​​of reactive power flow control device 1, respectively. This refers to the current flowing into the grid side; This refers to the current flowing through the H-bridge converter 4 after being filtered by LC filter 3; This is the AC side inverter voltage; The voltage of the capacitor in reactive power flow control device 1 is denoted as 1.

[0044] The reactive power flow control device 1 works by controlling the on / off switching of the IGBT switching devices in the upper and lower arms of the single-phase full-bridge circuit, causing them to output an equivalent voltage phasor with controllable amplitude and phase. This output voltage is then filtered by the LC filter 3 and input to the line via a single-turn coupled transformer. Therefore, the reactive power flow control device 1 can be equivalently represented as a controlled voltage source connected in series on the line, thereby controlling the power flow of the line. The equivalent circuit of the reactive power flow control device 1 connected to the power system is as follows: Figure 4 As shown, it is a dual-power supply system with a first-terminal voltage amplitude of The phase angle is The amplitude of the terminal voltage is The phase angle is The equivalent impedance of the line is ; This is the equivalent output voltage; The current amplitude of the transmission line is set to 0° initially.

[0045] When reactive power flow control equipment 1 is connected to the power system, the transmission line current is:

[0046]

[0047] Therefore, if reactive power flow control device 1 is not connected to the system or is not running, ignoring line resistance, the line current amplitude is:

[0048]

[0049] In the formula, For transmission line current; , which is the phase angle difference between the voltages at the beginning and end.

[0050] Since the phase angle of the line current is set to 0° and equipment losses are ignored, then:

[0051]

[0052] Therefore, it can be seen that the connection of reactive power flow control device 1 only changes the amplitude of the controlled line current but not its phase. Lag That is, when the equivalent output capacitive voltage is reached, As the line current increases, the line transmission power increases, but the maximum increase in line transmission power depends on the equipment capacity and the line transmission capacity. When Advanced That is, when the equivalent output inductive voltage is... As the line current decreases, the line transmission power decreases. When When the line current is zero, the voltage across the line impedance is also zero, and the line transmits zero power. At this point, the line current reverses, and the line power flow reverses. Therefore, the reactive power flow control device 1 can realize power flow control and power flow reversal, and flexibly transmit the line power flow value and direction within a certain range.

[0053] Therefore, reactive power flow control device 1 is connected to the system for operation injection. Apparent power at the head end of the transmission line for:

[0054]

[0055] Furthermore, the apparent power at the end of the transmission line for:

[0056]

[0057] Therefore, based on the apparent power at the beginning and end of the transmission line, the active power at the beginning and end of the line can be determined as follows:

[0058]

[0059] In the formula, P A P B These are the active power at the beginning and end of the line, respectively.

[0060] The reactive power at the beginning and end of the transmission line can be determined based on the apparent power at the beginning and end of the line:

[0061]

[0062]

[0063] In the formula, Q A Q B These are the reactive power at the beginning and end of the line, respectively.

[0064] Therefore, after the reactive power flow control equipment 1 is put into operation, the changes in the active power and reactive power at the beginning and end of the line are:

[0065]

[0066] In the formula, This represents the change in the active power of the line; , These represent the changes in reactive power at the beginning and end of the line, respectively.

[0067] The difference in reactive power at the beginning and end of a transmission line for:

[0068]

[0069] Furthermore, the reactive power loss generated by the equivalent impedance of the transmission line for:

[0070]

[0071] Reactive power injected into the transmission line by reactive power control equipment 1 for:

[0072]

[0073] Therefore, it can be seen that reactive power flow control device 1 changes... The magnitude and phase of the reactive power can be changed to alter the amount of reactive power injected into the line, while also regulating the active power at both ends of the line, thus achieving power flow control of the line.

[0074] When fluctuations in renewable energy power cause sudden changes in reactive power demand, the power system's output power (i.e., the active and reactive power of renewable energy equipment), line power flow data (current and voltage), and equipment operating status data (operating status information of key equipment such as transformers, circuit breakers, and capacitors, including parameters such as equipment temperature and pressure) are collected in real time to serve as operating data.

[0075] Next, based on the characteristics of the power system and the cycle of reactive power demand changes, a suitable time window size is determined, such as 15 minutes, 30 minutes, or 1 hour. The time window is then slid across the operating data in steps of a certain size (e.g., 1 minute). After each slide, statistical analysis is performed on the data within the current time window to calculate statistics such as average, maximum, minimum, and standard deviation, in order to extract features related to reactive power demand, such as the rate of change of output power, fluctuations in line power flow, and trends in equipment operating status. Time series analysis methods (such as exponential smoothing and ARIMA models) are then used to analyze the extracted features, thereby predicting the trend of reactive power demand changes in the power system within a future preset time period (5-10 seconds), thus obtaining the target value of reactive power demand.

[0076] The collected operational data can also be preprocessed, including data cleaning and normalization, and then converted into a format suitable for LSTM model input. This data is then input into the LSTM model trained using historical operational data, so that the model outputs the reactive power demand trend of the power system in the next 5 to 10 seconds, thus obtaining the reactive power demand target value.

[0077] This invention, by collecting and analyzing operational data in real time to predict reactive power demand trends, enables timely adjustments to the reactive power compensation devices of the power system. This prevents problems such as voltage fluctuations and power factor decline caused by insufficient or excessive reactive power, ensuring the safe and stable operation of the power system. Accurate prediction of reactive power demand targets helps to rationally allocate reactive power resources, avoid over-compensation or under-compensation of reactive power, improve the operating efficiency of the power system, and reduce operating costs. By monitoring and predicting changes in reactive power demand in real time, the power system can quickly respond to fluctuations in renewable energy generation, improving its capacity to absorb renewable energy.

[0078] S2. When the target value of reactive power demand is within the adjustment capacity constraint range of the reactive power flow control equipment, multiple target devices are determined based on the capacity margin of the reactive power flow control equipment and its electrical distance from the new energy equipment.

[0079] Specifically, it is determined whether the target value of reactive power demand is within the adjustment capacity constraint range of the reactive power flow control equipment (i.e., the reactive power output range of reactive power flow control equipment 1). If it meets the constraint range, the target equipment selection process is initiated; otherwise, the demand is compressed proportionally to adjust it to the constraint range before the target equipment selection process is initiated.

[0080] In one embodiment, determining multiple target devices based on the capacity margin of the reactive power flow control equipment and its electrical distance from the renewable energy equipment includes:

[0081] Obtain the capacity margin of the reactive power flow control equipment, and determine the electrical distance between the reactive power flow control equipment and the new energy equipment by the impedance modulus or electrical coupling degree of the reactive power flow control equipment.

[0082] The capacity margin and the electrical distance are normalized, and the normalization results are weighted and summed to obtain the priority weight of the reactive power flow control equipment.

[0083] Based on the aforementioned priority weights, the reactive power flow control devices are sorted from high to low to construct a control queue;

[0084] Based on the target value of reactive power demand, a number of target devices are selected from the adjustment queue according to a weighted ratio.

[0085] Specifically, this invention uses the difference between the maximum reactive power output of the reactive power control device 1 and the current reactive power output of the reactive power control device 1, i.e., the current remaining adjustable reactive power of the device, as the capacity margin of the reactive power control device 1 and obtains it; calculates the impedance modulus of the line between the reactive power control device 1 and the new energy equipment, and uses the reciprocal of the impedance modulus as the electrical distance between the two, or calculates the electrical coupling degree between the reactive power control device 1 and the new energy equipment (such as the sensitivity of the node admittance matrix), and uses the absolute value of the differential result of the coupling degree as the electrical distance between the two.

[0086] Both capacity margin and electrical distance are normalized to become dimensionless values ​​between 0 and 1. The two normalization results are then weighted and summed to obtain the priority weight of each reactive power flow control device 1. The sum of the capacity margin weight and the electrical distance weight is 1. Preferably, the capacity margin weight is 0.7 to emphasize response capability, and the electrical distance weight is 0.3 to emphasize control efficiency.

[0087] Based on the calculated priority weights, the reactive power flow control equipment 1 is sorted from high to low to form a control queue. According to the target value of reactive power demand, the control tasks are allocated according to the priority weight ratio, which is the reactive power compensation amount of the equipment. A greedy algorithm can be used to call the equipment in turn until the demand is met. If the control amount of the equipment exceeds its margin, it is marked as full load and the remaining demand is reallocated to the second-best equipment. Finally, several target equipment and their allocated reactive power compensation amounts are determined.

[0088] This invention selects the optimal equipment for reactive power compensation through a comprehensive evaluation of electrical distance and capacity margin, thereby improving control efficiency. The normalization process and weighted summation mechanism enable the scheme to flexibly adapt to different system scenarios, ensuring that the adjustment priority is scientific and reasonable. The target equipment is selected according to the weight ratio to ensure the rapid and stable operation of the critical path and avoid resource waste, thereby maximizing the reactive power compensation effect.

[0089] S3. Construct a quadratic programming model based on the reactive power demand target value and solve it to obtain the target equipment output strategy and send it to the corresponding target equipment so as to control each target equipment to regulate the power flow of the line through decoupling control technology.

[0090] In one embodiment, the step of constructing and solving a quadratic programming model based on the target reactive power demand value to obtain the target equipment output strategy includes:

[0091] The loss data, output voltage, and usage capacity of each target device are obtained in order to construct the operating function of each target device using the Lagrange method.

[0092] Collect the real-time power flow values ​​of the controlled lines of each target device, and use the sum of squares of the errors between the real-time power flow values ​​and the given reference values ​​as the optimization function for each target device;

[0093] Based on the number of target devices, a device quantity variable function is constructed, and based on the reactive power demand target value, a planning sub-model for each target device is constructed through each of the operation functions, each of the optimization functions, and the device quantity variable function;

[0094] The various planning sub-models are integrated to generate a quadratic programming model. Under preset constraints, the quadratic programming model is solved by calling the interior point method solver to obtain the output voltage amplitude and phase distribution of each target device as the output strategy of the target device.

[0095] Specifically, in the system-level control process, this invention acquires real-time information such as loss data, output voltage (e.g., rated voltage, actual operating voltage), and usage capacity (e.g., rated capacity, current usage capacity) of each target device from the power system monitoring system. It then uses the Lagrange method to incorporate these factors into the device's loss data, output voltage, and usage capacity, constructing the target device's operating function, which is expressed by the following formula:

[0096]

[0097]

[0098]

[0099]

[0100] In the formula, , , , Let R be the operating function, loss function, device output voltage, and utilization capacity evaluation function of the i-th target device, respectively; where the loss function represents the total power loss of the i-th target device during operation, including resistive loss, switching loss, and harmonic loss; se The equivalent series resistance of the target equipment (including the filter inductor resistance and the H-bridge converter on-resistance); i se2,i f is the effective value of the filtered current flowing through the i-th target device; sw E is the switching frequency of the H-bridge converter. on E off Energy loss during the turn-on and turn-off of a single IGBT device; I h,i Z h,i α and β are the effective value of the h-th harmonic current and the corresponding harmonic impedance, respectively; α, β, and γ are weighting coefficients used to balance the contributions of different loss terms. The weighting coefficients are dynamically generated by a multi-factor optimization model based on equipment operating status parameters and historical performance data. Among them, α corresponds to conductor loss weight, β is related to the operating conditions of switching devices, γ reflects the harmonic suppression requirements, and λ is the number of target devices. The voltage injected into the line by the i-th target device can also be understood as the output voltage of the device. , These are the rated output voltage and rated capacity of the i-th target device, respectively; Let be the utilization capacity of the i-th target device. Wherein, the loss function... All the units in the formula are completely consistent, using the watt (W) as the unified unit, which is the unit of power loss. First, the first term of the formula... Represents conductor loss, where resistance (Unit: ohms Ω) and the square of the current Multiplying (unit: amperes²) yields Ω. A 2 =W, which directly corresponds to the Joule heat loss in the power system. Secondly, the second term... Description of switching losses: switching frequency (Unit: Hertz (Hz), i.e., number of switches per second) and energy per switch The product of (unit: joules J) is converted to (1 / s) by unit conversion. J = J / s = W, which reflects the total power loss in the time domain during high-frequency switching operation. Its physical mechanism stems from the dynamic switching characteristics of power electronic devices. Finally, the third term, harmonic loss... In the middle, the square of the current (A²) and impedance The product of (Ω) also yields A. 2 Ω=W.

[0101] In addition, the constraints of the running function for:

[0102]

[0103] In the formula, The equation-based operational constraints for the i-th target device include the total injection voltage equation constraint; The inequality operation constraints for the i-th target device include single device output constraints, transformer voltage constraints, transformer capacity constraints, and line power flow constraints. , These are the lower and upper limits of the inequality constraints, respectively.

[0104] Real-time power flow data (active power and reactive power) of the controlled lines of each target device is collected, and the sum of squared errors between the real-time power flow values ​​and the given reference values ​​is used as the optimization objective function to minimize the power flow error. Then, a device quantity variable function is constructed based on the number of target devices in operation, considering the impact of device combinations on reactive power compensation effectiveness, so that the reactive power compensation of the target devices meets the reactive power demand target value. Based on the reactive power demand target value, the operation function, optimization function, and device quantity variable function are integrated to construct a planning sub-model for each target device. For the reactive power compensation demand of a certain area, the model considers the reactive power compensation effect and cost under different device combinations, and optimizes the output strategy of each device through the sub-model. The planning sub-model is expressed by the following formula:

[0105]

[0106]

[0107] In the formula, This is the planning sub-model for the i-th target device; , These are the real-time trend value and the given reference value, respectively. This is a function of the equipment quantity variable, which can also be understood as an additional term related to the equipment quantity, used to quantify the impact of the number of target equipment invested on economic efficiency or resource consumption; The number of target equipment to be deployed; This refers to the total lifecycle cost (including purchase, installation, and maintenance costs) of a single target device.

[0108] By integrating the planning sub-models of each target device, a quadratic planning model can be generated, which is expressed by the following formula:

[0109]

[0110] Finally, under preset constraints, the quadratic programming model is solved by calling the interior point method solver to obtain the output voltage amplitude and phase distribution of each target device as the output strategy of the target device.

[0111] This invention, by constructing and solving a quadratic programming model, can accurately formulate the output strategy of target equipment based on the reactive power demand target value, ensuring the reactive power balance of the power system and improving its stability and reliability. The system-level control process comprehensively considers various factors such as the total injection voltage required for line power flow regulation, line power flow constraints, individual equipment output limits, and transformer-related constraints, enabling coordinated operation of multiple reactive power flow regulation devices, thereby achieving more reasonable optimization of the active and reactive power flow of the lines. Using the sum of squares of the errors between the real-time power flow value and the given reference value as the optimization function, the operation of the target equipment can be made as close as possible to the ideal state, reducing power flow errors and improving the operating efficiency of the power system. By constructing a device quantity variable function and combining it with the reactive power demand target value, the number of target devices can be rationally configured under the premise of meeting reactive power demand, avoiding equipment redundancy or insufficiency and improving the economy of the power system.

[0112] In one embodiment, the preset constraints include:

[0113] The output constraint of a single device is expressed by the following formula:

[0114]

[0115] In the formula, k is the efficiency constraint coefficient, which is taken as 0.8.

[0116] Transformer voltage constraint is expressed by the following formula:

[0117]

[0118] In the formula, This refers to the maximum voltage that the reactive power flow control device 1 is allowed to inject into the transmission line.

[0119] Transformer capacity constraints are expressed by the following formula:

[0120]

[0121] In the formula, The rated power of the single-turn coupling transformer between the reactive power flow control equipment 1 and the transmission line.

[0122] It also includes: total injection voltage constraint, which is expressed by the following formula:

[0123]

[0124] In the formula, n represents the number of reactive power flow control devices 1.

[0125] Line power flow constraints are expressed by the following formula:

[0126]

[0127]

[0128]

[0129] In the formula, and These correspond to the minimum and maximum values ​​of the active and reactive power of the controlled line, respectively. These correspond to the minimum and maximum current values ​​of the controlled circuit, respectively. , These are the currents corresponding to the reactive power of the controlled circuit.

[0130] The step of solving the quadratic programming model by calling an interior-point solver under preset constraints to obtain the output voltage amplitude and phase distribution of each target device as the output power strategy of the target device includes:

[0131] Under the preset constraints, the quadratic programming model is solved once by calling the interior point method solver to obtain the initial output voltage amplitude and phase allocation of each target device.

[0132] If the initial output voltage amplitude and phase distribution do not meet the output constraint of the single device or the transformer capacity constraint, the transformer voltage constraint is adjusted to form a soft constraint for the transformer voltage.

[0133] The square of the transformer voltage soft constraint is used as a penalty term, and the quadratic programming model is updated based on the penalty term to obtain the quadratic programming target model.

[0134] Under the constraints of the output of a single device, the capacity of the transformer, and the soft constraint of the transformer voltage, the quadratic programming target model is solved twice by calling the interior point method solver to obtain the output voltage amplitude and phase allocation of each target device as the output strategy of the target device.

[0135] Specifically, under preset constraints, this invention calls an interior-point solver (such as CPLEX, Gurobi, etc.) to solve the quadratic programming model once, obtaining the initial output voltage amplitude and phase distribution of each target device; it checks whether the initial output voltage amplitude and phase distribution exceed the device's output range. If there are any non-compliance issues, it can be understood that the model has no solution. By adjusting the transformer voltage constraints, such as adjusting the local voltage fluctuation limit from ±2% to ±3%, or expanding the voltage limit, a soft constraint for the transformer voltage is formed. The square of the soft constraint for the transformer voltage is then used as a penalty term, and the penalty term is added to the quadratic programming model to update it, thus obtaining the quadratic programming target model.

[0136] The original transformer voltage constraint under the preset constraint is replaced by a soft constraint on the transformer voltage to form a new constraint. Under the new constraint, the updated quadratic programming objective model is solved twice by calling the interior point method solver to obtain the output voltage amplitude and phase distribution of each objective device. The strategy is then checked again. If the check is successful, it is used as the output strategy of the objective device and output to each objective device so that each objective device can adjust the power flow of the controlled line according to the received strategy. Otherwise, the output strategy of each objective function is resolved according to the constraint adjustment method until the calculated strategy meets the constraint.

[0137] This invention, by solving a quadratic programming model, can obtain the optimal output voltage amplitude and phase allocation of each target device under various constraints, thereby formulating a reasonable power output strategy for the target devices and improving the operating efficiency and stability of the energy system. The introduction of transformer voltage soft constraints and penalty terms allows for dynamic adjustment and re-solving of the model when the initial solution does not meet certain constraints, enhancing the algorithm's adaptability to complex constraints. The interior-point solver exhibits high accuracy and efficiency in handling quadratic programming problems, quickly finding the optimal solution that satisfies the constraints, providing a reliable decision-making basis for the operation of practical systems.

[0138] In one embodiment, controlling each of the target devices to regulate the line power flow through decoupling control technology includes:

[0139] Construct a loop model of each target device in a three-phase stationary coordinate system (abc), and perform a single-phase Park transformation on each loop model to obtain the voltage model and current model of each target device in a two-phase synchronous rotating coordinate system.

[0140] Intermediate variables are introduced into each of the voltage models to perform cross-decoupling, resulting in decoupled models for each of the target devices. A PI controller is then used to process each of the decoupled models to obtain reference voltage values ​​for each of the target devices.

[0141] The Park transform and feedforward decoupling method are used to process each current model to obtain the current processing model of each target device. Then, the PI controller is used to process each current processing model to obtain the reference current value of each target device.

[0142] Based on the reference voltage values ​​and the reference current values, a modulation signal is generated for the H-bridge converter 4 in each of the target devices, and the bypass switch 2 is controlled according to the modulation signal to obtain the equivalent voltage phasor to control the power flow regulation of the line in each of the target devices.

[0143] Specifically, in the device-level control process, in order to maintain the voltage stability of the DC capacitor 5 of the reactive power flow regulation device 1 and to perform power flow regulation, the control quantity is the modulation ratio of the single-phase H-bridge. and trigger phase angle To construct the loop model of the target device in the abc three-phase stationary coordinate system, it is expressed by the following formula:

[0144]

[0145]

[0146] In the formula, This refers to the voltage difference across the series connection point of the target device.

[0147] To achieve single-phase coordinate transformation, a model is constructed that lags behind the original variables. The new variable, assuming For the original variable, To delay its variables, If we consider the directional phase, then:

[0148]

[0149] In the formula, , These are the new variables and their lagged values, respectively. Variables.

[0150] Voltage outer loop control block diagram as follows Figure 5 As shown, it is important to note that Figure 5 Unlabeled parts of all calculation units are added by default. Performing a single-phase Park transformation on the loop model of each target device yields the voltage and current models of the corresponding target device in a two-phase synchronous rotating coordinate system, expressed by the following formula:

[0151]

[0152]

[0153] In the formula, The voltage difference across the series connection point of the target device; For network-side frequency; , i se2 q-axis and d-axis components in a synchronously rotating coordinate system; , i se1 q-axis and d-axis components in a synchronous rotating coordinate system.

[0154] According to the voltage model, by It is also affected by the output voltage. The influence of the filter inductor. To facilitate control, cross-decoupling is implemented, and an intermediate variable is introduced. The decoupling model of each target device is obtained, which is expressed by the following formula:

[0155]

[0156] in,

[0157]

[0158] thus, Decoupling has been achieved between the current and its d-axis and q-axis components. A PI controller can be used to process each of the decoupling models to obtain the reference voltage values ​​of each target device. , It is expressed by the following formula:

[0159]

[0160] in, , These are the proportional and integral coefficients, respectively. , They are respectively , The reference value is generated by the voltage outer loop control strategy.

[0161] The current inner loop control block diagram is as follows: Figure 6 As shown, similarly, Figure 6 Unlabeled parts of all calculation units are defaulted to addition. In the inner current loop, this invention employs a control method combining current state feedback and voltage feedforward compensation, performing Park transformation on each current model. The d-axis and q-axis components are also coupled, therefore feedforward decoupling is used, let:

[0162]

[0163] In the formula, , These are proportional and integral gains, respectively. , They are respectively d-axis and q-axis components , The reference values ​​are generated by the DC capacitor voltage loop and specified by the user according to voltage control requirements.

[0164] The current processing model for each target device can then be obtained, which is expressed by the following formula:

[0165]

[0166] By processing each current processing model using a PI controller, the reference current value for each target device can be obtained. , Based on the reference voltage and reference current values, a suitable modulation strategy (such as PWM modulation) is adopted to generate a modulation signal for the H-bridge converter 4. Then, based on the modulation signal of each target device, the on / off state of its included bypass switch 2 is controlled, thereby changing the output voltage and current of its own H-bridge converter 4, and obtaining an equivalent voltage phasor with adjustable amplitude and phase to control each target device to regulate the power flow of the line.

[0167] The ultimate goal of the voltage loop control of the reactive power flow control device 1 is to maintain the stability of its own DC capacitor 5 voltage and the output voltage of the tracking device. Only when the DC capacitor 5 voltage is controlled to be stable can the device work reliably. The stability of the capacitor voltage requires the support of active power, that is, the capacitor voltage is strongly correlated with the d-axis component of the grid-side injected voltage. Therefore, the d-axis component is given by controlling the capacitor voltage.

[0168] The device-level control process employed in this invention focuses on maintaining the stable voltage of the device's own DC capacitor 5. By constructing an accurate mathematical model and adopting advanced decoupling control technology, the control accuracy and response speed are improved, ensuring reliable operation of the device under various operating conditions. This greatly enhances the accuracy and stability of reactive power flow regulation. By generating a modulation signal and controlling the bypass switch 2, the output of the target device can be flexibly adjusted to adapt to different operating conditions and demand changes. By using a PI controller to process the decoupling model and the current processing model, precise control of the output voltage and current of the target device can be achieved, improving control accuracy and response speed.

[0169] S4. Obtain the actual power data of the power system after power flow regulation through each of the target equipment lines, and calculate the deviation between the actual power data and the reactive power demand target value; wherein, the actual power data is the active and reactive power of the line.

[0170] S5. When the deviation exceeds the preset deviation threshold, the reactive power demand target value is incrementally corrected, and the target equipment output strategy generation process is iteratively executed according to the corrected reactive power demand target value until the final actual power data does not exceed the preset deviation threshold, so as to realize the regulation of line power flow in the power system.

[0171] Specifically, when the deviation exceeds the preset deviation threshold, a correction process is triggered. Based on the direction (positive / negative) and magnitude of the deviation, the reactive power demand target value is proportionally corrected, and the output strategy of each device is recalculated based on the corrected reactive power demand target value until the deviation converges.

[0172] To address the problem of unreasonable reactive power flow distribution caused by differences in line impedance and regional load characteristics, this invention precisely controls the equivalent voltage phasor output of the reactive power flow control device 1 to achieve precise adjustment of the line current amplitude. It flexibly increases or decreases the line transmission power according to actual needs, optimizing the power flow distribution, reducing reactive power losses during transmission, effectively improving line voltage fluctuations, enhancing the operational stability of power equipment, increasing grid transmission efficiency, and reducing power transmission costs. Addressing the shortcomings of traditional reactive power compensation equipment, such as its single adjustment method, slow response speed, and susceptibility to inrush currents during switching, this invention proposes a control strategy that enables rapid and precise control of reactive power flow. The designed reactive power flow control device 1 can track changes in system reactive power demand in real time, quickly adjust the output, and ensure reliable system operation without adversely affecting system stability. Considering the challenges posed by the intermittency and volatility of renewable energy generation to grid reactive power flow control, this invention optimizes the control strategy to enable the reactive power flow control device 1 to work collaboratively with renewable energy generation, stabilizing system voltage, suppressing power oscillations, and ensuring the safe and reliable operation of the power system even with large-scale renewable energy integration. To address the regulation conflicts and resource waste caused by the independent operation and lack of coordination mechanisms of reactive power compensation devices in existing power systems, this invention addresses the issues from multiple perspectives, including system constraints, regulation demand, and device utilization. It achieves coordinated output of multiple reactive power flow control devices 1, fully leverages the efficiency of each device through optimized control, and realizes global optimization of active and reactive power flow of the lines, thereby improving the economic operation level and power supply reliability of the power system.

[0173] In one embodiment, the method further includes:

[0174] The DC voltage is determined based on the working requirements of the reactive power flow control equipment and the voltage at the access point of the new energy equipment, and the ripple current is determined based on the circuit topology of the reactive power flow control equipment.

[0175] The capacitance value of the DC capacitor 5 is determined based on the DC voltage and the ripple current.

[0176] The normalized LPF is subjected to cutoff frequency transformation and characteristic impedance transformation to determine the parameters of the LC filter 3; wherein the normalized LPF is configured with an impedance of 1. And the cutoff frequency is Hz LPF.

[0177] Specifically, in the process of power flow regulation, the parameter design of the reactive power flow regulation equipment is crucial, as it directly affects equipment performance and system operation. This invention determines the DC voltage that the DC capacitor 5 can withstand based on the operating requirements of the reactive power flow regulation equipment (i.e., its rated voltage and voltage regulation margin) and the voltage at the access point of the new energy equipment. This ensures that the reactive power is matched to the AC voltage at the connection point and the required compensation capacity. Considering the frequent power fluctuations and large changes in reactive power compensation demand after the new energy equipment is connected, the reactive power demand target value Q of the system is determined using the formula... Preliminary estimate of capacitance value, of which Where f is the system frequency. To suppress DC-side voltage ripple, the allowable ripple voltage amplitude is specified to be 1%-5% of the DC voltage. The DC-side ripple current is calculated based on the estimated capacitance value, system frequency, and ripple voltage amplitude. The DC-side ripple current can also be calculated based on the working principle and circuit topology of the reactive power flow control equipment. A suitable capacitor can be selected based on its ripple current withstand capability, and the capacitor value can be estimated using the ripple current and allowable ripple voltage. The calculation process is expressed by the following formula:

[0178]

[0179] To ensure stable operation of the equipment under various working conditions, the final capacitance value is taken as 1.2-1.5 times the calculated value.

[0180] Furthermore, this invention employs a method based on a normalized LPF (Low Pass Filter) to design the parameters of the LC filter 3. First, the cutoff frequency of the normalized LPF is transformed to change its parameters, and then a characteristic impedance transformation is performed to obtain the parameters of the LC filter 3. The normalized LPF is configured such that its impedance is 1. And the cutoff frequency is The LPF of Hz. The transformation process of the normalized LPF is expressed by the following formula:

[0181]

[0182]

[0183] In the formula, These are the component parameter values ​​for the normalized LPF; These are the component parameters for LC filter 3.

[0184] Ultimately, based on the output signal characteristics of new energy equipment, such as wind farms, the characteristic impedance of the LC filter is generally required to be [specific value missing]. The frequency ranges from 30 to 70, and the cutoff frequency is set to 6 to 8 times the output signal frequency. This optimizes the filtering effect, reduces the impact of harmonics on the system, and ensures the power quality of the power grid.

[0185] In selecting the five parameters of the DC capacitor, this invention comprehensively considers various factors such as equipment operating requirements, system voltage level, compensation capacity requirements, ripple current, and voltage ripple, and enhances the reliability of equipment operation by reserving a certain safety margin. In designing the three parameters of the LC filter, a method based on normalized LPF is adopted, which simplifies the design process and can more effectively improve filtering performance, reduce the impact of harmonics on the system, and ensure the power quality of the power system.

[0186] This application proposes a line flow control method for power systems to address the issue of how to regulate line flow in a power system to adapt to changes in reactive power demand caused by the integration of new energy sources. The method involves real-time acquisition of power system operation data after the integration of new energy sources to predict the target reactive power demand for a predetermined period. When the target reactive power demand is within the regulation capacity range, multiple target devices (bypass switches, LC filters, H-bridge converters, and DC capacitors) are selected based on capacity margin and electrical distance. During system-level control, a quadratic programming model is constructed to solve for the output strategies of the target devices. At the device level, decoupling control technology is used to regulate line flow. The actual power data after regulation is obtained, and the deviation from the target value is calculated. If the deviation exceeds a threshold, the target value is incrementally corrected, and the output strategy is iteratively generated until the deviation meets the requirements. This achieves precise regulation of line flow in the power system, solving problems such as voltage instability caused by the intermittency and volatility of new energy generation in reactive power flow control.

[0187] It should be noted that although the steps in the flowchart above are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order requirement for the execution of these steps, and they can be executed in other orders.

[0188] In another embodiment, such as Figure 7 As shown, a second aspect of the present invention provides a line power flow control system for a power system, comprising:

[0189] The target prediction module 10 is used to collect the operating data of the power system after the connection of new energy equipment in real time, and predict the reactive power demand target value of the power system in a future preset period based on the operating data.

[0190] The equipment selection module 20 is used to determine multiple target devices based on the capacity margin of the reactive power flow control equipment and its electrical distance from the new energy equipment when the reactive power demand target value is within the adjustment capacity constraint range of the reactive power flow control equipment; the reactive power flow control equipment includes a bypass switch, an LC filter, an H-bridge converter, and a DC capacitor;

[0191] The power flow control module 30 is used to construct and solve a quadratic programming model based on the reactive power demand target value, obtain the target equipment output strategy, and send it to the corresponding target equipment to control each target equipment to regulate the power flow of the line through decoupling control technology.

[0192] Deviation calculation module 40 is used to obtain the actual power data of the power system after power flow regulation through each of the target equipment lines, and to calculate the deviation between the actual power data and the reactive power demand target value;

[0193] The iterative control module 50 is used to incrementally correct the reactive power demand target value when the deviation exceeds the preset deviation threshold, and iteratively execute the generation process of the target equipment output strategy according to the corrected reactive power demand target value until the final actual power data does not exceed the preset deviation threshold, so as to realize the control of the line power flow in the power system.

[0194] It should be noted that the various modules in the aforementioned power system line flow control system can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module. For specific limitations regarding the power system line flow control system, please refer to the limitations regarding the power system line flow control method above; both have the same function and role, and will not be repeated here.

[0195] A third aspect of the present invention provides an electronic device comprising:

[0196] Processor, memory, and bus;

[0197] The bus is used to connect the processor and the memory;

[0198] The memory is used to store operation instructions;

[0199] The processor is configured to execute the operation instructions by calling the operation instructions, thereby causing the processor to perform the operation corresponding to the line power flow control method for a power system as shown in the first aspect of this application.

[0200] In one alternative embodiment, an electronic device is provided, such as Figure 8 As shown, Figure 8The illustrated electronic device 5000 includes a processor 5001 and a memory 5003. The processor 5001 and the memory 5003 are connected, for example, via a bus 5002. Optionally, the electronic device 5000 may also include a transceiver 5004. It should be noted that in practical applications, the transceiver 5004 is not limited to one type, and the structure of this electronic device 5000 does not constitute a limitation on the embodiments of this application.

[0201] Processor 5001 may be a CPU, a general-purpose processor, a DSP, an ASIC, an FPGA, or other programmable logic device, transistor logic device, hardware component, or any combination thereof. It may implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. Processor 5001 may also be a combination that implements computational functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.

[0202] Bus 5002 may include a path for transmitting information between the aforementioned components. Bus 5002 may be a PCI bus or an EISA bus, etc. Bus 5002 can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 8 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0203] The memory 5003 may be a ROM or other type of static storage device capable of storing static information and instructions, RAM or other type of dynamic storage device capable of storing information and instructions, or it may be an EEPROM, CD-ROM or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto.

[0204] The memory 5003 is used to store application code that executes the scheme of this application, and its execution is controlled by the processor 5001. The processor 5001 is used to execute the application code stored in the memory 5003 to implement the content shown in any of the foregoing method embodiments.

[0205] Among them, electronic devices include, but are not limited to: mobile terminals such as mobile phones, laptops, digital radio receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), and in-vehicle terminals (such as in-vehicle navigation terminals), as well as fixed terminals such as digital TVs and desktop computers.

[0206] The fourth aspect of the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements a line power flow control method for a power system as shown in the first aspect of this application.

[0207] Another embodiment of this application provides a computer-readable storage medium storing a computer program that, when run on a computer, enables the computer to execute the corresponding content in the aforementioned method embodiments.

[0208] Furthermore, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method.

[0209] In summary, this invention relates to the field of power system technology, and discloses a method, system, equipment, and medium for line power flow regulation in power systems. It predicts the target reactive power demand value of the power system by collecting operational data after the integration of renewable energy equipment. When this value falls within the regulation capacity range of reactive power flow regulation equipment including bypass switches, LC filters, H-bridge converters, and DC capacitors, multiple target devices are determined based on the capacity margin of the equipment and its electrical distance from the renewable energy equipment. A quadratic programming model is constructed and solved based on the target reactive power demand value to obtain the output strategy of the target devices, which is then sent to the corresponding target devices to control the line power flow through decoupling control technology. The regulation results are verified; if the verification fails, the target reactive power demand value is incrementally corrected, and the strategy is re-solved until the final verification is successful, thereby achieving effective regulation of line power flow in the power system.

[0210] The various embodiments in this specification are described in a progressive manner. For directly identical or similar parts of the embodiments, refer to each other. Each embodiment focuses on its differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. It should be noted that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0211] The embodiments described above are merely preferred embodiments of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various improvements and substitutions without departing from the technical principles of this invention, and these improvements and substitutions should also be considered within the scope of protection of this application. Therefore, the scope of protection of this patent application should be determined by the scope of the claims.

Claims

1. A method for line power flow control in a power system, characterized in that, include: Real-time acquisition of power system operation data after the connection of new energy equipment, and prediction of the target value of reactive power demand of the power system in a future preset period based on the operation data; When the reactive power demand target value is within the adjustment capacity constraint range of the reactive power flow control equipment, multiple target devices are determined based on the capacity margin of the reactive power flow control equipment and its electrical distance from the new energy equipment; the reactive power flow control equipment includes a bypass switch, an LC filter, an H-bridge converter, and a DC capacitor; Based on the target value of reactive power demand, a quadratic programming model is constructed and solved to obtain the output strategy of the target equipment and send it to the corresponding target equipment so as to control each target equipment to regulate the power flow of the line through decoupling control technology. Obtain the actual power data of the power system after power flow regulation through each of the target equipment lines, and calculate the deviation between the actual power data and the reactive power demand target value; When the deviation exceeds the preset deviation threshold, the reactive power demand target value is incrementally corrected, and the target equipment output strategy generation process is iteratively executed according to the corrected reactive power demand target value until the final actual power data does not exceed the preset deviation threshold, so as to realize the regulation of line power flow in the power system. The determination of multiple target devices based on the capacity margin of the reactive power flow control equipment and its electrical distance from the new energy equipment includes: Obtain the capacity margin of the reactive power flow control equipment, and determine the electrical distance between the reactive power flow control equipment and the new energy equipment by the impedance modulus or electrical coupling degree of the reactive power flow control equipment. The capacity margin and the electrical distance are normalized, and the normalization results are weighted and summed to obtain the priority weight of the reactive power flow control equipment. Based on the aforementioned priority weights, the reactive power flow control devices are sorted from high to low to construct a control queue; Based on the target value of reactive power demand, a number of target devices are selected from the adjustment queue according to a weighted ratio.

2. The method for line power flow control in a power system according to claim 1, characterized in that, The real-time acquisition of power system operating data after the connection of new energy equipment, and the prediction of the power system's reactive power demand target value within a future preset period based on the operating data, includes: The power system's output power, line power flow data, and equipment operating status data are collected in real time after the new energy equipment is connected, and used as the operating data. The operating data is processed using a sliding time window or a pre-trained long short-term memory network to predict the reactive power demand trend of the power system within a future preset time period, thereby obtaining the target value of reactive power demand.

3. The method for line power flow control in a power system according to claim 1, characterized in that, The step of constructing and solving a quadratic programming model based on the target reactive power demand value to obtain the target equipment output strategy includes: The loss data, output voltage, and usage capacity of each target device are obtained in order to construct the operating function of each target device using the Lagrange method. Collect the real-time power flow values ​​of the controlled lines of each target device, and use the sum of squares of the errors between the real-time power flow values ​​and the given reference values ​​as the optimization function for each target device; Based on the number of target devices, a device quantity variable function is constructed, and based on the reactive power demand target value, a planning sub-model for each target device is constructed through each of the operation functions, each of the optimization functions, and the device quantity variable function; The various planning sub-models are integrated to generate a quadratic programming model. Under preset constraints, the quadratic programming model is solved by calling the interior point method solver to obtain the output voltage amplitude and phase distribution of each target device as the output strategy of the target device.

4. A method for line power flow control in a power system according to claim 3, characterized in that, The preset constraints include single device output constraints, transformer voltage constraints, and transformer capacity constraints; among which... The step of solving the quadratic programming model under preset constraints by calling an interior-point solver to obtain the output voltage amplitude and phase distribution of each target device as the output strategy of the target device includes: Under the preset constraints, the quadratic programming model is solved once by calling the interior point method solver to obtain the initial output voltage amplitude and phase allocation of each target device. If the initial output voltage amplitude and phase distribution do not meet the output constraint of the single device or the transformer capacity constraint, the transformer voltage constraint is adjusted to form a soft constraint for the transformer voltage. The square of the transformer voltage soft constraint is used as a penalty term, and the quadratic programming model is updated based on the penalty term to obtain the quadratic programming target model. Under the constraints of the output of a single device, the capacity of the transformer, and the soft constraint of the transformer voltage, the quadratic programming target model is solved twice by calling the interior point method solver to obtain the output voltage amplitude and phase allocation of each target device as the output strategy of the target device.

5. A method for line power flow control in a power system according to claim 1, characterized in that, The method of controlling each of the target devices to regulate the power flow of the line through decoupling control technology includes: Construct a loop model of each target device in a three-phase stationary coordinate system (abc), and perform a single-phase Park transformation on each loop model to obtain the voltage model and current model of each target device in a two-phase synchronous rotating coordinate system. Intermediate variables are introduced into each of the voltage models to perform cross-decoupling, resulting in decoupled models for each of the target devices. A PI controller is then used to process each of the decoupled models to obtain reference voltage values ​​for each of the target devices. The Park transform and feedforward decoupling method are used to process each current model to obtain the current processing model of each target device. Then, the PI controller is used to process each current processing model to obtain the reference current value of each target device. Based on the reference voltage values ​​and the reference current values, a modulation signal is generated for the H-bridge converter in each of the target devices, and the bypass switches are controlled according to the modulation signals to obtain an equivalent voltage phasor to control the power flow regulation of the line in each of the target devices.

6. A method for line power flow control in a power system according to claim 1, characterized in that, The method further includes: The DC voltage is determined based on the working requirements of the reactive power flow control equipment and the voltage at the access point of the new energy equipment, and the ripple current is determined based on the circuit topology of the reactive power flow control equipment. The capacitance value of the DC capacitor is determined based on the DC voltage and the ripple current; The normalized LPF is subjected to cutoff frequency transformation and characteristic impedance transformation to determine the parameters of the LC filter; wherein the normalized LPF is configured such that its impedance is 1. And the cutoff frequency is Hz LPF.

7. A line power flow control system for a power system, characterized in that, include: The target prediction module is used to collect real-time operating data of the power system after the connection of new energy equipment, and predict the target value of reactive power demand of the power system in a future preset period based on the operating data. The equipment selection module is used to determine multiple target devices based on the capacity margin of the reactive power flow control equipment and its electrical distance from the new energy equipment when the target value of reactive power demand is within the adjustment capacity constraint range of the reactive power flow control equipment. The reactive power flow control equipment includes a bypass switch, an LC filter, an H-bridge converter, and a DC capacitor. The power flow control module is used to construct and solve a quadratic programming model based on the reactive power demand target value, obtain the output strategy of the target equipment, and send it to the corresponding target equipment to control the power flow of the line through decoupling control technology. The deviation calculation module is used to obtain the actual power data of the power system after power flow regulation through each of the target equipment lines, and to calculate the deviation between the actual power data and the reactive power demand target value. The iterative control module is used to incrementally correct the reactive power demand target value when the deviation exceeds the preset deviation threshold, and iteratively execute the generation process of the target equipment output strategy according to the corrected reactive power demand target value until the final actual power data does not exceed the preset deviation threshold, so as to realize the control of the line power flow in the power system. The determination of multiple target devices based on the capacity margin of the reactive power flow control equipment and its electrical distance from the new energy equipment includes: Obtain the capacity margin of the reactive power flow control equipment, and determine the electrical distance between the reactive power flow control equipment and the new energy equipment by the impedance modulus or electrical coupling degree of the reactive power flow control equipment. The capacity margin and the electrical distance are normalized, and the normalization results are weighted and summed to obtain the priority weight of the reactive power flow control equipment. Based on the aforementioned priority weights, the reactive power flow control devices are sorted from high to low to construct a control queue; Based on the target value of reactive power demand, a number of target devices are selected from the adjustment queue according to a weighted ratio.

8. An electronic device, characterized in that, It includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor, when executing the computer program, implements the line power flow control method for a power system as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored computer program, wherein when the device containing the computer-readable storage medium executes the computer program, it implements the line power flow control method for a power system as described in any one of claims 1 to 6.

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