Flexible interconnection device intensive topology design method and system

Abstract

This invention provides a method and system for intensive topology design of flexible interconnected devices. The method includes: constructing a topology diagram of the flexible interconnected device; designing topology parameters based on the topology diagram, including series converter parameters, parallel converter parameters, multiple active power converter parameters, series-side injected voltage, parallel-side output current, complex power, MAB converter active power, and power transmission parameters; optimizing MAB control parameters using an improved Grey Wolf Extended Particle Swarm Optimization (PSO) algorithm, including filter capacitor parameters and filter inductor parameters; constructing a control function for the three-phase parallel-side converter based on the topology parameters after optimizing the MAB control parameters, and outputting the final control target based on the control function. This invention can improve the stability and reliability of power systems, reduce operation and maintenance costs, and enhance energy utilization efficiency and flexibility.

Description

Technical Field

[0001] This invention relates to the field of flexible interconnected power distribution systems, and in particular to a method and system for intensive topology design of flexible interconnected devices. Background Technology

[0002] Guided by the "dual carbon" goal, the new power system is accelerating its evolution towards greening, intensification, high quality and intelligence. Among them, in order to adapt to the large-scale access of distributed power sources and meet diverse electricity demand, the medium-voltage interconnected distribution system with flexible interconnection devices (FID) as its core has received widespread attention from the engineering and academic communities because it can become a key means to improve the flexibility and reliability of the distribution network.

[0003] To further leverage the advantages of converter-centric flexible interconnected power distribution systems, such as rapid response, controllable power flow, and fault isolation, a three-level structure is needed. However, while achieving voltage level increases, this type of three-level structure faces significant bottlenecks in multi-level expansion. Some scholars have also mentioned multi-level topology interconnection devices. These devices are simple in structure and easy to expand; when a voltage level increase is required, only the corresponding number of H-bridges and DC voltage regulation modules need to be added to the input and isolation stages. However, in such a structure, the impact of unbalanced loads is evenly distributed to the high-voltage grid side, and single-phase faults on the grid side are also evenly distributed to the load side. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for intensive topology design of flexible interconnect devices, aiming to solve at least one problem in the background art.

[0005] In a first aspect, the present invention provides a method for intensive topology design of flexible interconnect devices, characterized in that the method includes:

[0006] Construct a topology diagram for flexible interconnected devices;

[0007] The topology parameters are designed based on the topology diagram. The topology parameters include series converter parameters, parallel converter parameters, multi-active converter parameters, series side injection voltage, parallel side output current, complex power, MAB converter active power, and power transmission parameter design.

[0008] An improved gray wolf extended particle swarm optimization algorithm is used to optimize the MAB control parameters, which include filter capacitor parameters and filter inductor parameters.

[0009] After optimizing the MAB control parameters, a control function for the three-phase parallel converter is constructed based on the topology parameters, and the final control target is output based on the control function.

[0010] In some embodiments, the step of constructing a topology diagram for a multi-port active bridge unified power quality conditioner includes:

[0011] The topology of the flexible interconnection device includes a three-phase series converter, a three-phase parallel converter, and a MAB converter. The MAB converter includes multiple H-bridge converters and a high-frequency isolation transformer.

[0012] In some embodiments, the step of designing topology parameters based on the topology diagram, wherein the topology parameters include series converter parameters, parallel converter parameters, multi-active converter parameters, series-side injection voltage, parallel-side output current, complex power, MAB converter active power, and power transfer parameters, includes:

[0013] The expressions for the parameters of the series converter and the parallel converter are as follows:

[0014] ;

[0015] in, The capacitance value of the LC filter on the series side. This is the derivative of the three-phase voltage values ​​on the power consumption side. For the parallel side output current, For the power input current, The derivative of the three-phase voltage values ​​input to the grid side and connected in parallel. The inductance value of the series-side LC filter. This is the derivative of the three-phase current values ​​of the series-side converter. This is the input of the three-phase voltage values ​​on the parallel side of the power grid. The equivalent resistance on the series side. These are the three-phase current values ​​of the series-side converter. The three-phase output voltage on the parallel side, This is the equivalent inductance value on the grid side. The inductance value of the parallel filter. The derivative of the grid-side current value. The equivalent resistance on the parallel side, For grid-side current, Let be the port voltage at DC port i (i=1,2,3...n). This is the derivative of the input current on the power consumption side. Let x be the phase voltage of the power grid at node T, where x = a, b, c, representing phase a, phase b, and phase c, respectively.

[0016] The expression for complex power is:

[0017] ;

[0018] in, This is the conjugate value of the complex power generated by the power flowing through point T on the grid side. This is the conjugate value of the three-phase voltage input to the grid side on the parallel side. Let be the conjugate value of the complex power generated by the power flowing through node f on the power consumption side. This is the conjugate value of the three-phase voltage on the power consumption side. This is the injection voltage value on the series side. This is the conjugate value of the three-phase load line current. This is the conjugate value of the output current on the parallel side. The complex power generated by the series-side converter, The complex power generated by the parallel-side converter;

[0019] The expression for the series-side injected voltage is:

[0020] ;

[0021] in, This represents the rated voltage of the power grid, where k is the ratio of the actual voltage on the power grid side to the rated voltage. This is the ratio of the actual voltage on the power consumption side to the rated voltage. Phase angle shift of the negative power supply side voltage;

[0022] The expression for the parallel-side output current is:

[0023] ;

[0024] in, The complex power generated by the power flowing through node f on the power consumption side. The complex power generated by the power grid flowing through point T. The power factor angle at point f on the power consumption side is... The power factor angle at point T on the grid side;

[0025] The expression for the active power of the MAB converter is:

[0026] ;

[0027] in, This refers to the active power of the H-bridge inverter on the left side of the MAB. To extract the real part of the parameter within the parentheses, DC power absorbed by DC loads The active power generated on the grid side. This is the ratio of the injected voltage amplitude to the rated voltage amplitude. For the injected voltage phase angle, This represents the DC voltage at port m. Let m be the DC current at port m, where m represents any port.

[0028] The expression for the power transfer parameters is:

[0029] ;

[0030] in, This refers to the power transferred from port i to port j in the MAB converter. The number of turns in the winding at DC port i. Let j be the number of turns of the winding at DC port j. For switching frequency, Let be the equivalent coupling inductance between port i and port j. Let be the voltage at DC port i. The voltage at DC port j. Let be the phase difference ratio between port i and port j.

[0031] In some embodiments, the step of optimizing the MAB control parameters using an improved gray wolf extended particle swarm optimization algorithm, wherein the MAB control parameters include filter capacitor parameters and filter inductor parameters, includes:

[0032] The first constraint condition regarding the filter inductor parameter is constructed based on the following formula:

[0033] ;

[0034] The second constraint condition regarding the filter capacitor parameter is constructed based on the following formula:

[0035] ;

[0036] ;

[0037] The third constraint condition regarding the parameters of the filter capacitor and the filter inductor is constructed based on the following formula:

[0038] ;

[0039] in, This is the resonant frequency of the LC filter. The switching frequency of the series converter. The active power flowing through the series-parallel converters and the MAB converter. and These are the parameter coefficients of the series-side filter inductor and capacitor, respectively. and These are the parameter coefficients of the parallel-side filter inductor and DC capacitor, respectively. The equivalent coupling inductance parameter coefficients, This is the capacitance value of the DC port.

[0040] In some embodiments, the method further includes:

[0041] Randomly generate a wolf pack containing M gray wolves, and update the position of the entire wolf pack according to the following formula:

[0042] ;

[0043] Introducing the EPD mechanism, the positions of the top 60% of Grey Wolves are updated according to the following formula:

[0044] ;

[0045] ;

[0046] The fitness function of the improved Gray Wolf Extended Particle Swarm Optimization algorithm is expressed as follows:

[0047] ;

[0048] in, Let be the distance between the gray wolf and its prey in the t-th iteration. For the attraction coefficient vector, Let be the position vector of the leader wolf in the t-th iteration. The leader wolf includes... Wolf, Wolf, Wolf, Let be the current position vector of the i-th wolf in the t-th iteration. The candidate positions are updated according to the guidance of the leader wolf p. The bounding coefficient vector, As a key parameter, , All are random variables, and their values ​​are all in the range [0,1]. To lead the wolf The position obtained under the guidance in the (t+1)th iteration. In the t-th generation of the gray wolf pack The wolf's position vector For pointing The encirclement coefficient vector used when wolves are present. For the i-th wolf in the t-th generation and Dimensional distance estimation vectors between wolf locations To lead the wolf The position obtained under the guidance in the (t+1)th iteration. In the t-th generation of the gray wolf pack The wolf's position vector For pointing The encirclement coefficient vector used when wolves are present. For the i-th wolf in the t-th generation and Dimensional distance estimation vectors between wolf locations In order to be in The position obtained by guiding the wolf in the (t+1)th iteration. In the t-th generation of the gray wolf pack The wolf's position vector For pointing The encirclement coefficient vector used when wolves are present. For the i-th wolf in the t-th generation and Dimensional distance estimation vectors between wolf locations Let T1 be the new position of the i-th gray wolf in generation t+1, where T1 is the start time of the optimization time window and T2 is the end time of the optimization time window.

[0049] In some embodiments, the step of constructing a control function for the three-phase parallel-side converter based on the topology parameters after optimizing the MAB control parameters, and outputting the final control target based on the control function, includes:

[0050] Construct the control function based on the following formula:

[0051] ;

[0052] Where x = a, b, c, , and All are weighting factors. For the ultimate control objective, This represents the predicted value of the three-phase voltage on the power consumption side during the (k+1)th sampling period. This is a reference value for the three-phase voltage on the power supply side of the topology in UPQC mode. This represents the predicted value of the three-phase current of the series-side converter in the (k+1)th sampling period. This is a reference value for the three-phase current of the series-side converter in FCL mode. This is a reference value for the three-phase voltage on the power supply side of the topology in UPFC mode;

[0053] Construct the constraints for the control function using the following formula:

[0054] ;

[0055] ;

[0056] ;

[0057] in, For symbolic functions, The correction function can be defined as the deviation between the load impedance and its set threshold. It serves as an auxiliary indicator for fault recovery assessment but is not suitable for fault detection. These are the weighting coefficients.

[0058] In some embodiments, the method further includes:

[0059] The predicted value is obtained using the following formula:

[0060] ;

[0061] ;

[0062] ;

[0063] in, For the discrete system matrix, The predicted value of the three-phase voltage on the power consumption side in the kth sampling period is given. This represents the predicted value of the three-phase current of the series-side converter in k sampling periods. For the control matrix, This represents the predicted value of the three-phase output voltage on the parallel side during k sampling periods. Let be the predicted value of the input current on the power consumption side in k sampling periods. This represents the predicted value of the three-phase voltage on the parallel side of the grid input in the kth sampling period. Let A be the derivative of the predicted value of the parallel three-phase voltage input from the grid side in k sampling periods, and let A be the continuous-time system matrix. The sampling period is B is the identity matrix, and B is the continuous-time input matrix. For zero array, It is a 3×3 identity matrix;

[0064] The current and voltage reference values ​​in UPQC mode are obtained using the following formulas:

[0065] ;

[0066] ;

[0067] in, , , These are the reference values ​​for phase a, phase b, and phase c voltages on the power side of the topology in UPQC mode. The rated amplitude of the voltage at the common coupling point p node. The power angular frequency, , , These are the reference values ​​for the a-phase current, b-phase current, and c-phase current of the series-side converter in FCL mode, respectively. The preset desired amplitude of the output current on the series side;

[0068] The current and voltage reference values ​​in UPFC mode are obtained using the following formulas:

[0069] ;

[0070] ;

[0071] ;

[0072] in, , , These are the reference values ​​for the voltages of phase a, phase b, and phase c on the power side of the topology in UPFC mode. , These are the reference values ​​for the d-axis and q-axis components of the three-phase voltage on the power side of the topology in UPFC mode. For the instantaneous electrical angle of the synchronously rotating coordinate system, , These are the parameters of the three-phase voltage on the power consumption side in the d-axis and q-axis components, respectively. , These are the parameters of the input current on the power consumption side in the d-axis and q-axis components, respectively. , These are the predicted values ​​of the d-axis component and the q-axis component of the input current on the power consumption side during the kth sampling period, respectively. , , The input currents for phases a, b, and c on the power consumption side are respectively. , , These are the voltage values ​​for phases a, b, and c on the power consumption side, respectively.

[0073] Secondly, the present invention provides a intensive topology design system for flexible interconnect devices, the system comprising:

[0074] The topology graph construction module is used to build topology graphs for flexible interconnected devices.

[0075] The parameter design module is used to design topology parameters based on the topology diagram. The topology parameters include series converter parameters, parallel converter parameters, multiple active converter parameters, series side injection voltage, parallel side output current, complex power, MAB converter active power, and power transmission parameter design.

[0076] The parameter optimization module is used to optimize the MAB control parameters using an improved gray wolf extended particle swarm optimization algorithm. The MAB control parameters include filter capacitor parameters and filter inductor parameters.

[0077] The control target output module is used to optimize the MAB control parameters, construct a control function for the three-phase parallel-side converter based on the topology parameters, and output the final control target based on the control function.

[0078] Thirdly, the present invention provides a storage medium that stores one or more programs, which, when executed by a processor, implement the above-described flexible interconnect device intensive topology design method.

[0079] Fourthly, the present invention provides an electronic device, the electronic device comprising a memory and a processor, wherein:

[0080] The memory is used to store computer programs;

[0081] When the processor executes the computer program stored in the memory, it implements the above-described flexible interconnect device intensive topology design method.

[0082] Compared with the prior art, the present invention has the following advantages:

[0083] This invention provides a precise parameter basis for device operation by constructing a topology diagram and designing various topology parameters such as series, parallel, and MAB converters. An improved Grey Wolf Extended Particle Swarm Optimization (GPA) algorithm is used to optimize MAB control parameters, effectively improving the accuracy and efficiency of parameter optimization and ensuring stable device operation. Based on the optimized parameters, a three-phase parallel-side converter control function is constructed and the final control target is output, enabling precise control of device operation and achieving multiple functions such as power quality regulation, fault current limiting, and flexible power control. This improves the stability and reliability of the power system, reduces operation and maintenance costs, and enhances energy utilization efficiency and flexibility. Attached Figure Description

[0084] Figure 1 This is a flowchart of a flexible interconnect device intensive topology design method proposed in an embodiment of the present invention;

[0085] Figure 2 A block diagram of a multi-port active bridge unified power quality conditioner topology system;

[0086] Figure 3 This is a schematic diagram of a flexible interconnect device intensive topology design system proposed in an embodiment of the present invention.

[0087] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0088] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, but does not exclude other elements or objects.

[0089] like Figure 1 As shown, an embodiment of the present invention proposes a method for intensive topology design of flexible interconnect devices, the method comprising steps S101 to S104, wherein:

[0090] Step S101: Construct a topology diagram for the flexible interconnected device;

[0091] It should be noted that the topology design of this flexible interconnect device is applied to the topology system of a multi-port active bridge unified power quality conditioner, such as... Figure 2 As shown, the topology of the multi-port active bridge unified power quality conditioner mainly consists of a three-phase parallel VSC (P-VSC), a MAB converter, and three single-phase series VSCs (E-VSC). One end of the parallel converter is connected to the grid side, and the other end of the parallel side is connected to the multi-port active bridge converter through a DC capacitor. One end of the series converter is connected to the grid, and the other end is connected to the multi-port active bridge converter.

[0092] The series-side converter is a three-phase series-side converter used to improve voltage quality, effectively eliminating all voltage-related problems, including voltage droop, voltage surge, harmonics, and imbalance, while also isolating the transmission of harmful currents. The parallel-side converter is a three-phase parallel-side converter that addresses current-related problems, including low power factor, harmonics, and imbalance, by injecting current with adjustable amplitude and phase angle. Compared to traditional flexible interconnect devices, this topology connects three DC-port series-side converters and one DC-port parallel-side converter, completely eliminating the need for traditional power frequency transformers, thus offering higher power density. Furthermore, the MAB acts as an "energy router" in the proposed flexible interconnect equipment, providing multiple DC power electronic interfaces to further enhance the flexibility of the equipment.

[0093] Furthermore, in some embodiments, the parallel-side converter is a three-phase full-bridge converter, which injects current into node T through an L-filter. This is to compensate for the power factor of node T or support the voltage of node T. The series-side converter consists of three single-phase full-bridge converters, which inject voltage into node f through an LC filter. To achieve voltage compensation at node f It can control line power flow; in addition, it can also be controlled as a controllable current source to suppress downstream fault current. The multi-active bridge converter mainly consists of multiple H-bridge converters and a high-frequency isolation transformer, realizing the coupling of the high-voltage DC port of the parallel-side converter with the three low-voltage DC ports of the series-side converter, as well as the DC port connecting photovoltaic and energy storage, and enabling arbitrary flow of active power between multiple DC ports.

[0094] In a flexible interconnected system with multiple active bridge converters, the series and parallel converters and the multiple active bridge converters themselves do not absorb or release energy, but they can provide more paths for active and reactive power. Furthermore, various DC micro-sources, such as photovoltaics, can inject active power into nodes T and f through the four DC terminals of the multiple active bridge converter.

[0095] Step S102: Design topology parameters according to the topology diagram. The topology parameters include series converter parameters, parallel converter parameters, multi-active converter parameters, series side injection voltage, parallel side output current, complex power, MAB converter active power, and power transmission parameter design.

[0096] In some embodiments, the expressions for designing the parameters of the series and parallel converters satisfy:

[0097] ;

[0098] The above can be simplified to:

[0099] ;

[0100] in, The capacitance value of the LC filter on the series side. This is the derivative of the three-phase voltage values ​​on the power consumption side. For the parallel side output current, For the power input current, The derivative of the three-phase voltage values ​​input to the grid side and connected in parallel. The inductance value of the series-side LC filter. This is the derivative of the three-phase current values ​​of the series-side converter. This is the input of the three-phase voltage values ​​on the parallel side of the power grid. The equivalent resistance on the series side. These are the three-phase current values ​​of the series-side converter. The three-phase output voltage on the parallel side, This is the equivalent inductance value on the grid side. The inductance value of the parallel filter. The derivative of the grid-side current value. The equivalent resistance on the parallel side, For grid-side current, Let be the port voltage at DC port i (i=1,2,3...n). This is the derivative of the input current on the power consumption side. Let x be the phase voltage of the power grid at node f, and let x = a, b, c, representing phase a, phase b, and phase c.

[0101] The expression for complex power is:

[0102] ;

[0103] in, This is the conjugate value of the complex power generated by the power flowing through point T on the grid side. This is the conjugate value of the three-phase voltage input to the grid side on the parallel side. Let be the conjugate value of the complex power generated by the power flowing through node f on the power consumption side. This is the conjugate value of the three-phase voltage on the power consumption side. This is the injection voltage value on the series side. This is the conjugate value of the three-phase load line current. This is the conjugate value of the output current on the parallel side. The complex power generated by the series-side converter, The complex power generated by the parallel-side converter;

[0104] The expression for the series-side injected voltage is:

[0105] ;

[0106] in, This represents the rated voltage of the power grid, where k is the ratio of the actual voltage on the power grid side to the rated voltage. This is the ratio of the actual voltage on the power consumption side to the rated voltage. The phase angle shift of the negative power-side voltage, after compensation, is reflected in the power-side voltage. , ;

[0107] Then flow through the node The current vector can be further written as:

[0108] ;

[0109] The magnitude of the current flowing through the series converter is:

[0110] ;

[0111] Similarly, the current output by the parallel-side converter can be further written as:

[0112] ;

[0113] The expression for the parallel-side output current is:

[0114] ;

[0115] in, The complex power generated by the power flowing through node f on the power consumption side. The complex power generated by the power grid flowing through point T. The power factor angle at point f on the power consumption side is... The power factor angle at point T on the grid side;

[0116] The active power parameters of the series-parallel converters and MAB converters are designed to meet the following requirements:

[0117] ;

[0118] The expression for the active power of the MAB converter is:

[0119] ;

[0120] in, This refers to the active power of the H-bridge inverter on the left side of the MAB. To extract the real part of the parameter within the parentheses, DC power absorbed by DC loads The active power flowing through the series-parallel converters and the MAB converter. The active power generated on the grid side. This is the ratio of the injected voltage amplitude to the rated voltage amplitude. For the injected voltage phase angle, This represents the DC voltage at port m. Let m be the DC current at port m, where m represents any port.

[0121] The MAB converter uses the fourth DC port as a reference, and the DC port voltage of the MAB converter satisfies:

[0122] ;

[0123] in and . Indicates DC port The number of turns in the winding. Port With port The equivalent coupling inductance between them. For port The phase difference ratio between port j and port j. and Representing ports respectively Place The bridge's DC output current and photovoltaic injection current;

[0124] The expression for the power transfer parameters is:

[0125] ;

[0126] The output power of port i is:

[0127] ;

[0128] in, This refers to the power transferred from port i to port j in the MAB converter. The number of turns in the winding at DC port i. Let j be the number of turns of the winding at DC port j. For switching frequency, Let be the equivalent coupling inductance between port i and port j. Let be the voltage at DC port i. The voltage at DC port j. Let be the phase difference ratio between port i and port j.

[0129] Furthermore, in some embodiments, the flow through the port a、b and c The total active power is equal to the power flowing through the port. d active power .therefore, It can be represented as:

[0130] ;

[0131] in Indicates the three-phase active power on the series side. Let be the voltage at DC port d. Let be the current at DC port i.

[0132] So, port d The output power is:

[0133] ;

[0134] The port leakage inductance parameter can then be calculated as follows:

[0135] ;

[0136] in, This represents the ratio of the phase difference between port d and port x.

[0137] In summary, regarding the formulas of the aforementioned MAB mathematical model, it should be noted that traditional distribution networks rely on mechanical switches, which cannot achieve flexible control of interconnected power, thus limiting their effectiveness in improving system operational economy. This leads to problems such as insufficient power exchange capability, increased voltage fluctuations, and weak fault ride-through capability in traditional distribution networks. To address these issues, this invention proposes a mathematical model based on the MAB converter. Utilizing soft-switching, a new fully controlled power electronic device, it can achieve more precise power flow regulation and enhance fault ride-through capability. Compared to traditional architectures, the integrated MAB converter eliminates the need for series transformer design, significantly improving system power density. Its multi-DC port design supports the access of distributed energy sources at different voltage levels, enhancing system compatibility and operational flexibility, thereby improving the adaptability and operational efficiency of the distribution network.

[0138] Step S103: The improved gray wolf extended particle swarm optimization algorithm is used to optimize the MAB control parameters, which include filter capacitor parameters and filter inductor parameters;

[0139] It should be noted that in this step, the MAB control parameters are adaptively adjusted by using an improved Gray Wolf Optimization-Extended Particle Swarm Optimization (GWO-EPD) with evolutionary population dynamics, so that the parameters are within a reasonable range to achieve the optimal balance between system performance and resource utilization.

[0140] In some embodiments, the selection of filter inductor parameters is mainly to ensure that the output voltage is as large as possible and the voltage drop across the inductor is as small as possible. The first constraint condition regarding the filter inductor parameters is constructed according to the following formula:

[0141] ;

[0142] The selection of filter capacitor parameters is mainly based on the reactive power it absorbs, and is generally limited to absorbing reactive power less than 10% of the rated output power. Furthermore, LC Filter resonant frequency Requires a series converter The switching frequency is at least 10 times lower. A second constraint on the filter capacitor parameters is constructed based on the following formula:

[0143] ;

[0144] ;

[0145] The third constraint condition regarding the parameters of the filter capacitor and the filter inductor is constructed based on the following formula:

[0146] ;

[0147] in, This is the resonant frequency of the LC filter. The switching frequency of the series converter. The active power flowing through the series-parallel converters and the MAB converter. and These are the parameter coefficients of the series-side filter inductor and capacitor, respectively. and These are the parameter coefficients of the parallel-side filter inductor and DC capacitor, respectively. The equivalent coupling inductance parameter coefficients, This is the capacitance value of the DC port.

[0148] To improve algorithm performance, this embodiment employs a strategy: eliminating individuals with the lowest fitness and repositioning them. The initialization phase of the algorithm is consistent with the standard Gray Wolf Optimization (GWO): a population of M gray wolves is randomly generated. Subsequently, the three best individuals are selected based on their fitness values ​​and designated as leader wolves. , and The remaining individuals are Wolves. During the iteration process, , and The wolves, acting as leaders, gradually move towards the simulated "prey" position. The position updates of the entire wolf pack are guided by these leaders, and their behavior is modeled by the following position update equation:

[0149] ;

[0150] This formula defines the distance between the gray wolf and its prey, with key parameters... Used for the exploration and development of balancing algorithms, its value decreases linearly from 2 to 0 during the iteration process. Where:

[0151] ;

[0152] Where t is the current iteration number, It represents the maximum number of iterations.

[0153] Introducing the EPD mechanism, the positions of the top 60% of Grey Wolves are updated according to the following formula:

[0154] ;

[0155] ;

[0156] The fitness function of the improved Gray Wolf Extended Particle Swarm Optimization algorithm is expressed as follows:

[0157] ;

[0158] in, Let be the distance between the gray wolf and its prey in the t-th iteration. For the attraction coefficient vector, Let be the position vector of the leader wolf in the t-th iteration. The leader wolf includes... Wolf, Wolf, Wolf, Let be the current position vector of the i-th wolf in the t-th iteration. The candidate positions are updated according to the guidance of the leader wolf p. The bounding coefficient vector, As a key parameter, , All are random variables, and their values ​​are all in the range [0,1]. To lead the wolf The position obtained under the guidance in the (t+1)th iteration. In the t-th generation of the gray wolf pack The wolf's position vector For pointing The encirclement coefficient vector used when wolves are present. For the i-th wolf in the t-th generation and Dimensional distance estimation vectors between wolf locations To lead the wolf The position obtained under the guidance in the (t+1)th iteration. In the t-th generation of the gray wolf pack The wolf's position vector For pointing The encirclement coefficient vector used when wolves are present. For the i-th wolf in the t-th generation and Dimensional distance estimation vectors between wolf locations In order to be in The position obtained by guiding the wolf in the (t+1)th iteration. In the t-th generation of the gray wolf pack The wolf's position vector For pointing The encirclement coefficient vector used when wolves are present. For the i-th wolf in the t-th generation and Dimensional distance estimation vectors between wolf locations Let T1 be the new position of the i-th gray wolf in generation t+1, where T1 is the start time of the optimization time window and T2 is the end time of the optimization time window.

[0159] The aforementioned optimization algorithm has the advantages of simple model, few hyperparameters, and low implementation and parameter tuning costs in application. Furthermore, it is based on... The multi-guided encirclement-tracking mechanism allows for a natural switch between global exploration and local development, resulting in stable convergence and easy escape from local optima.

[0160] Step S104: After optimizing the MAB control parameters, construct a control function for the three-phase parallel converter based on the topology parameters, and output the final control target based on the control function.

[0161] It should be noted that, regarding the switching control of MAB in multiple modes, existing research mostly focuses on a single operating mode, typically employing fixed-parameter controllers and hard switching logic: the objectives and constraints of different modes are uniformly processed, and switching occurs via fixed rules or dead zones, with weights remaining unchanged with operating conditions. This approach fails to adequately consider the time-varying nature of operating conditions and the differences in objectives between modes, resulting in insufficient adaptability under complex disturbances and a tendency to trigger transient shocks, power flow oscillations, or voltage quality degradation. This invention proposes a weighting factor, which, by introducing continuous scheduling variables and piecewise differentiable transition functions, dynamically reconstructs the cost functions and constraints of modes such as UPFC / UPQC / FCL within the prediction domain, achieving soft switching and seamless transition. Based on the correlation between weights and constraints and local energy and fluctuation intensity, the control quantity and reference trajectory remain continuously bounded, effectively suppressing transient shocks and synergistically meeting the comprehensive needs of power flow control, power quality management, and fault current limiting.

[0162] Specifically, the control function is constructed according to the following formula:

[0163] ;

[0164] Where x = a, b, c, , and All are weighting factors. For the ultimate control objective, This represents the predicted value of the three-phase voltage on the power consumption side during the (k+1)th sampling period. This is a reference value for the three-phase voltage on the power supply side of the topology in UPQC mode. This represents the predicted value of the three-phase current of the series-side converter in the (k+1)th sampling period. This is a reference value for the three-phase current of the series-side converter in FCL mode. This is a reference value for the three-phase voltage on the power supply side of the topology in UPFC mode;

[0165] Construct the constraints for the control function using the following formula:

[0166] ;

[0167] ;

[0168] ;

[0169] in, For symbolic functions, The correction function can be defined as the deviation between the load impedance and its set threshold. It serves as an auxiliary indicator for fault recovery assessment but is not suitable for fault detection. These are the weighting coefficients.

[0170] Furthermore, in some embodiments, the predicted value is obtained according to the following formula:

[0171] ;

[0172] ;

[0173] ;

[0174] in, For the discrete system matrix, The predicted value of the three-phase voltage on the power consumption side in the kth sampling period is given. This represents the predicted value of the three-phase current of the series-side converter in k sampling periods. For the control matrix, This represents the predicted value of the three-phase output voltage on the parallel side during k sampling periods. Let be the predicted value of the input current on the power consumption side in k sampling periods. This represents the predicted value of the three-phase voltage on the parallel side of the grid input in the kth sampling period. Let A be the derivative of the predicted value of the parallel three-phase voltage input from the grid side in k sampling periods, and let A be the continuous-time system matrix. The sampling period is B is the identity matrix, and B is the continuous-time input matrix. For zero array, It is a 3×3 identity matrix. The capacitance value of the LC filter on the series side. This represents the inductance value of the LC filter on the series side;

[0175] The current and voltage reference values ​​in UPQC mode are obtained using the following formulas:

[0176] ;

[0177] ;

[0178] in, , , These are the reference values ​​for phase a, phase b, and phase c voltages on the power side of the topology in UPQC mode. The rated amplitude of the voltage at the common coupling point p node. The power angular frequency, , , These are the reference values ​​for the a-phase current, b-phase current, and c-phase current of the series-side converter in FCL mode, respectively. The preset desired amplitude of the output current on the series side;

[0179] The current and voltage reference values ​​in UPFC mode are obtained using the following formulas:

[0180] ;

[0181] ;

[0182] ;

[0183] in, , , These are the reference values ​​for the voltages of phase a, phase b, and phase c on the power side of the topology in UPFC mode. , These are the reference values ​​for the d-axis and q-axis components of the three-phase voltage on the power side of the topology in UPFC mode. For the instantaneous electrical angle of the synchronously rotating coordinate system, , These are the parameters of the three-phase voltage on the power consumption side in the d-axis and q-axis components, respectively. , These are the parameters of the input current on the power consumption side in the d-axis and q-axis components, respectively. , These are the predicted values ​​of the d-axis component and the q-axis component of the input current on the power consumption side during the kth sampling period, respectively. , , The input currents for phases a, b, and c on the power consumption side are respectively. , , These are the voltage values ​​for phases a, b, and c on the power consumption side, respectively.

[0184] In summary, this invention proposes a compact topology design and control for a flexible interconnected device with multifunctional integration. The operation control method includes: establishing the topology diagram, which mainly consists of a three-phase series-side converter (E-VSC) composed of three single-phase H-bridges, a three-phase parallel-side converter (P-VSC), and a multi-port active-bridge (MAB) converter; based on the topology diagram, designing the topology parameters according to preset conditions, mainly including the parameter design of the series and parallel converters and the parameter design of the multiple active-bridge converters; and so on. Subsequently, based on the set topology parameters, an algorithm flowchart is established to optimize system performance within a reasonable range. Simultaneously, combining the improved Grey Wolf Optimization-Extended Particle Swarm Optimization (GWO-EPD) algorithm and the operational constraints of each mode, a comprehensive cooperative control algorithm and operating parameters are used to generate an overall model predictive control scheme. Compared to traditional flexible interconnection devices, in this topology, the multiple active bridge converter connects the series-side converters of three DC ports and the parallel-side converter of one DC port, completely avoiding the use of traditional power frequency transformers. Therefore, this topology has the advantage of higher power density. Furthermore, the MAB also acts as an "energy router" in the proposed flexible interconnection equipment, providing multiple DC power electronic interfaces, further enhancing the flexibility of the flexible interconnection equipment.

[0185] like Figure 3 As shown, one embodiment of the present invention proposes a intensive topology design system for flexible interconnect devices, the system comprising:

[0186] Topology graph construction module 10 is used to construct a topology graph of the flexible interconnected device;

[0187] The parameter design module 20 is used to design topology parameters according to the topology diagram. The topology parameters include series converter parameters, parallel converter parameters, multi-active converter parameters, series side injection voltage, parallel side output current, complex power, MAB converter active power, and power transmission parameter design.

[0188] The parameter optimization module 30 is used to optimize the MAB control parameters using an improved gray wolf extended particle swarm optimization algorithm. The MAB control parameters include filter capacitor parameters and filter inductor parameters.

[0189] The control target output module 40 is used to optimize the MAB control parameters, construct a control function for the three-phase parallel-side converter based on the topology parameters, and output the final control target based on the control function.

[0190] In another aspect, the present invention also proposes a storage medium having stored one or more programs thereon, which, when executed by a processor, implement the above-described flexible interconnect device intensive topology design method.

[0191] In another aspect, the present invention also proposes an electronic device, including a memory and a processor, wherein the memory is used to store a computer program and the processor is used to execute the computer program stored in the memory to realize the above-mentioned flexible interconnection device intensive topology design method.

[0192] Those skilled in the art will understand that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can mean any means that can contain stored, communicated, propagated, or transmitted programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0193] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0194] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0195] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A method for intensive topology design of flexible interconnection devices, characterized in that, The method includes: Construct a topology diagram for flexible interconnected devices; The topology parameters are designed based on the topology diagram. The topology parameters include series converter parameters, parallel converter parameters, multiple active converter parameters, series side injection voltage, parallel side output current, complex power, MAB converter active power, and power transmission parameter design. The expressions for the parameters of the series converter and the parallel converter are as follows: ； in, The capacitance value of the LC filter on the series side. This is the derivative of the three-phase voltage values ​​on the power consumption side. For the parallel side output current, For the power input current, The derivative of the three-phase voltage values ​​input to the grid side and connected in parallel. The inductance value of the series-side LC filter. This is the derivative of the three-phase current values ​​of the series-side converter. This is the input of the three-phase voltage values ​​on the parallel side of the power grid. The equivalent resistance on the series side. These are the three-phase current values ​​of the series-side converter. For the three-phase output voltage on the parallel side, This is the equivalent inductance value on the grid side. The inductance value of the parallel filter. The derivative of the grid-side current value. The equivalent resistance on the parallel side, For grid-side current, Let be the port voltage at DC port i (i=1,2,3...n). This is the derivative of the input current on the power consumption side. Let x be the phase voltage of the power grid at node T, where x = a, b, c, representing phase a, phase b, and phase c, respectively. The expression for complex power is: ； in, This is the conjugate value of the complex power generated by the power flowing through point T on the grid side. This is the conjugate value of the three-phase voltage input to the grid side on the parallel side. Let be the conjugate value of the complex power generated by the power flowing through node f on the power consumption side. This is the conjugate value of the three-phase voltage on the power consumption side. This is the injection voltage value on the series side. This is the conjugate value of the three-phase load line current. This is the conjugate value of the output current on the parallel side. The complex power generated by the series-side converter, The complex power generated by the parallel-side converter; The expression for the series-side injected voltage is: ； in, This represents the rated voltage of the power grid, where k is the ratio of the actual voltage on the power grid side to the rated voltage. It is the ratio of the actual voltage on the power consumption side to the rated voltage. Phase angle shift of the negative power supply side voltage; The expression for the parallel-side output current is: ； in, The complex power generated by the power flowing through node f on the power consumption side. The complex power generated by the power grid flowing through point T. The power factor angle at point f on the power consumption side is... The power factor angle at point T on the grid side; The expression for the active power of the MAB converter is: ； in, This refers to the active power of the converter on the left side of the MAB. To extract the real part of the parameter within the parentheses, DC power absorbed by DC loads The active power generated on the grid side. This is the ratio of the injected voltage amplitude to the rated voltage amplitude. For the injected voltage phase angle, This represents the DC voltage at port m. Let m be the DC current at port m, where m represents any port. The expression for the power transfer parameters is: ； in, This refers to the power transferred from port i to port j in the MAB converter. The number of turns in the winding at DC port i. Let j be the number of turns of the winding at DC port j. For switching frequency, Let be the equivalent coupling inductance between port i and port j. Let be the voltage at DC port i. The voltage at DC port j. This is the phase difference ratio between port i and port j; An improved gray wolf extended particle swarm optimization algorithm is used to optimize the MAB control parameters, which include filter capacitor parameters and filter inductor parameters. The first constraint condition regarding the filter inductor parameter is constructed based on the following formula: ； The second constraint condition regarding the filter capacitor parameter is constructed based on the following formula: ； ； The third constraint condition regarding the parameters of the filter capacitor and the filter inductor is constructed based on the following formula: ； in, This is the resonant frequency of the LC filter. The switching frequency of the series converter. The active power flowing through the series-parallel converters and the MAB converter. and These are the parameter coefficients of the series-side filter inductor and capacitor, respectively. and These are the parameter coefficients of the parallel-side filter inductor and DC capacitor, respectively. The equivalent coupling inductance parameter coefficients, This is the capacitance value of the DC port; Randomly generate a wolf pack containing M gray wolves, and update the position of the entire wolf pack according to the following formula: ； Introducing the EPD mechanism, the positions of the top 60% of Grey Wolves are updated according to the following formula: ； ； The fitness function of the improved Gray Wolf Extended Particle Swarm Optimization algorithm is expressed as follows: ； in, Let be the distance between the gray wolf and its prey in the t-th iteration. For the attraction coefficient vector, Let be the position vector of the leader wolf in the t-th iteration. The leader wolf includes... Wolf, Wolf, Wolf, Let be the current position vector of the i-th wolf in the t-th iteration. The candidate positions are updated according to the guidance of the leader wolf p. This is the enclosing coefficient vector. As a key parameter, , All are random variables, and their values ​​are all in the range [0,1]. To lead the wolf The position obtained under the guidance in the (t+1)th iteration. In the t-th generation of the gray wolf pack The wolf's position vector For pointing The encirclement coefficient vector used when wolves are present. For the i-th wolf in the t-th generation and Dimensional distance estimation vectors between wolf locations To lead the wolf The position obtained under the guidance in the (t+1)th iteration. In the t-th generation of the gray wolf pack The wolf's position vector For pointing The encirclement coefficient vector used when wolves are present. For the i-th wolf in the t-th generation and Dimensional distance estimation vectors between wolf locations In order to be in The position obtained by guiding the wolf in the (t+1)th iteration. In the t-th generation of the gray wolf pack The wolf's position vector For pointing The encirclement coefficient vector used when wolves are present. For the i-th wolf in the t-th generation and Dimensional distance estimation vectors between wolf locations Let T1 be the new position of the i-th gray wolf in generation t+1, where T1 is the start time of the optimization time window and T2 is the end time of the optimization time window. After optimizing the MAB control parameters, a control function for the three-phase parallel converter is constructed based on the topology parameters, and the final control target is output based on the control function.

2. The intensive topology design method for flexible interconnection devices according to claim 1, characterized in that, The steps for constructing the topology diagram of the multi-port active bridge unified power quality conditioner include: The topology of the flexible interconnection device includes a three-phase series converter, a three-phase parallel converter, and a MAB converter. The MAB converter includes multiple H-bridge converters and a high-frequency isolation transformer.

3. The intensive topology design method for flexible interconnection devices according to claim 2, characterized in that, The steps of optimizing the MAB control parameters, constructing a control function for the three-phase parallel converter based on the topology parameters, and outputting the final control target based on the control function include: Construct the control function based on the following formula: ； Where x = a, b, c, , and All are weighting factors. For the ultimate control objective, This represents the predicted value of the three-phase voltage on the power consumption side during the (k+1)th sampling period. This is a reference value for the three-phase voltage on the power supply side of the topology in UPQC mode. This represents the predicted value of the three-phase current of the series-side converter in the (k+1)th sampling period. The reference values ​​are for the three-phase currents of the series-side converter in FCL mode. This is a reference value for the three-phase voltage on the power supply side of the topology in UPFC mode; Construct the constraints for the control function using the following formula: ； ； ； in, For symbolic functions, This is a correction function, defined as the deviation between the load impedance and its set threshold. It serves as an auxiliary indicator for fault recovery assessment but is not suitable for fault detection. These are the weighting coefficients.

4. The intensive topology design method for flexible interconnection devices according to claim 3, characterized in that, The method further includes: The predicted value is obtained using the following formula: ； ； ； in, For the discrete system matrix, The predicted value of the three-phase voltage on the power consumption side in the kth sampling period is given. This represents the predicted value of the three-phase current of the series-side converter in k sampling periods. For the control matrix, This represents the predicted value of the three-phase output voltage on the parallel side during k sampling periods. Let be the predicted value of the input current on the power consumption side in k sampling periods. This represents the predicted value of the three-phase voltage on the parallel side of the grid input in the kth sampling period. Let A be the derivative of the predicted value of the parallel three-phase voltage input from the grid side in k sampling periods, and let A be the continuous-time system matrix. The sampling period is B is the identity matrix, and B is the continuous-time input matrix. For zero array, It is a 3×3 identity matrix; The current and voltage reference values ​​in UPQC mode are obtained using the following formulas: ； ； in, , , These are the reference values ​​for phase a, phase b, and phase c voltages on the power side of the topology in UPQC mode. The rated amplitude of the voltage at the common coupling point p node. The power angular frequency, , , These are the reference values ​​for the a-phase current, b-phase current, and c-phase current of the series-side converter in FCL mode, respectively. The preset desired amplitude of the output current on the series side; The current and voltage reference values ​​in UPFC mode are obtained using the following formulas: ； ； ； in, , , These are the reference values ​​for the voltages of phase a, phase b, and phase c on the power side of the topology in UPFC mode. , These are the reference values ​​for the d-axis and q-axis components of the three-phase voltage on the power side of the topology in UPFC mode. For the instantaneous electrical angle of the synchronously rotating coordinate system, , These are the parameters of the three-phase voltage on the power consumption side in the d-axis and q-axis components, respectively. , These are the parameters of the input current on the power consumption side in the d-axis and q-axis components, respectively. , These are the predicted values ​​of the d-axis component and the q-axis component of the input current on the power consumption side during the kth sampling period, respectively. , , The input currents for phases a, b, and c on the power consumption side are respectively. , , These are the voltage values ​​for phases a, b, and c on the power consumption side, respectively.

5. A flexible interconnect device intensive topology design system, used to implement the flexible interconnect device intensive topology design method as described in any one of claims 1-4, characterized in that, The system includes: The topology graph construction module is used to build topology graphs for flexible interconnected devices. The parameter design module is used to design topology parameters based on the topology diagram. The topology parameters include series converter parameters, parallel converter parameters, multiple active converter parameters, series side injection voltage, parallel side output current, complex power, MAB converter active power, and power transmission parameter design. The parameter optimization module is used to optimize the MAB control parameters using an improved gray wolf extended particle swarm optimization algorithm. The MAB control parameters include filter capacitor parameters and filter inductor parameters. The control target output module is used to optimize the MAB control parameters, construct a control function for the three-phase parallel-side converter based on the topology parameters, and output the final control target based on the control function.

6. A storage medium, characterized in that, The storage medium stores one or more programs that, when executed by a processor, implement the intensive topology design method for flexible interconnect devices as described in any one of claims 1-4.

7. An electronic device comprising a memory and a processor, wherein: The memory is used to store computer programs; When the processor executes the computer program stored in the memory, it implements the intensive topology design method for flexible interconnect devices as described in any one of claims 1-4.

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