A method and system for dynamic reactive power control based on phase modifier

Abstract

The present application relates to the technical field of phase modifier control, in particular to a dynamic reactive power control method and system based on a phase modifier, comprising: acquiring real-time voltage deviation of the phase modifier during operation, and calling corresponding pole phase group rearrangement scheme; calculating magnetic density increment of end structure according to phase advance operation depth of the phase modifier, and activating end magnetic circuit optimization control logic when exceeding temperature rise intervention threshold, adjusting the magnetic circuit by simulating magnetic shielding, setting the material properties of the anti-magnetic steel, and introducing equivalent slot impedance; calculating end potential gradient according to the magnetic density increment, and activating end circuit blocking control logic when exceeding circulating current blocking threshold, blocking the circuit anomaly by inserting equivalent insulation sleeve, short-circuiting positioning rib, and laying equivalent insulation sheet; and coupling the output parameters of the two control logics with the pole phase group rearrangement scheme to generate dynamic reactive power distribution instructions. The method can solve the end temperature rise and circulating current discharge problems during the phase advance operation of the phase modifier, and improve the operation stability.

Description

Technical Field

[0001] This invention relates to the field of synchronous condenser control technology, and in particular to a method and system for dynamic reactive power control based on synchronous condensers. Background Technology

[0002] As an important reactive power compensation device in the power system, the dynamic reactive power control performance of synchronous condensers directly affects the voltage stability of the power system. Existing dynamic reactive power control technologies for synchronous condensers mostly regulate reactive power output by acquiring voltage deviation and invoking preset parallel branch connection strategies or pole-phase group rearrangement schemes to maintain system voltage stability.

[0003] Conventional control schemes of this type only focus on the macroscopic adjustment of reactive power output and do not consider the changes in the magnetoelectric characteristics of the end components during the phase advance operation of the synchronous condenser. When the phase advance depth of the synchronous condenser changes, the magnetic flux density of the end components will increase. Conventional control does not take targeted measures to deal with this increase in magnetic flux density, which can easily lead to increased eddy current losses and excessive temperature rise of the components. At the same time, the increase in magnetic flux density will cause changes in the potential gradient at the end. Conventional control cannot effectively block the circulating current and discharge path generated by this, which can easily lead to problems such as partial discharge and excessive circulating current losses, affecting the safety and reliability of the synchronous condenser operation.

[0004] When the synchronous condenser is in phase advance operation, the potential for temperature rise caused by excessively high end magnetic flux density increment and the potential for circulating current discharge caused by excessively high end potential gradient are key problems that are difficult to solve with conventional control technology. It is necessary to design control logic in a targeted manner to make up for the shortcomings of conventional technology in end magnetic circuit and circuit control. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology and propose a dynamic reactive power control method and system based on a synchronous condenser.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a dynamic reactive power control method based on a synchronous condenser, comprising:

[0007] Obtain the real-time voltage deviation during synchronous condenser operation, and based on the real-time voltage deviation, call the corresponding pole phase group rearrangement scheme from the preset parallel branch connection strategy library;

[0008] Based on the current advance operating depth of the condenser, the magnetic flux density increment at the end structure is calculated. When the magnetic flux density increment exceeds the preset temperature rise intervention threshold, the end magnetic circuit optimization control logic is activated. The end magnetic circuit optimization control logic includes: simulating the application of a magnetic shielding structure in the control strategy to increase the end magnetic reluctance, setting the material properties of the pressure ring and pressure finger to antimagnetic steel to increase the magnetic reluctance of the structure, and introducing an equivalent slotted impedance in the teeth of the stepped plate to reduce eddy current loss.

[0009] Simultaneously, the end potential gradient is calculated based on the magnetic flux density increment. When the end potential gradient exceeds the preset circulating current blocking threshold, the end circuit blocking control logic is activated. The end circuit blocking control logic includes: inserting an equivalent insulating sleeve model between the end of the positioning rib and the punch to block the discharge channel; setting the positioning rib to a short-circuited state to provide a path for the circulating current; and laying equivalent insulating sheets on both sides of the end core section and the magnetic shield to block the relative discharge channels of the ventilation channel steel and the pressure finger.

[0010] The output parameters of the activated end magnetic circuit optimization control logic and the end circuit blocking control logic are coupled with the pole phase group rearrangement scheme to generate the dynamic reactive power distribution command of the synchronous condenser under the current operating conditions.

[0011] As a further aspect of the present invention, obtaining the real-time voltage deviation during the operation of the synchronous condenser includes:

[0012] The real-time voltage deviation is determined by the instantaneous difference between the actual voltage at the grid connection point and the nominal voltage of the system.

[0013] Collect the instantaneous three-phase voltage values ​​at the synchronous condenser connection point and calculate the arithmetic mean of the instantaneous three-phase voltage values ​​as the actual voltage at the grid connection point;

[0014] Read the current system nominal voltage setting value from the power grid dispatching system;

[0015] The actual voltage at the grid connection point is instantaneously compared with the nominal voltage setting value of the system to calculate the real-time voltage deviation.

[0016] The real-time voltage deviation is normalized into an adjustment factor for controlling branch adjustment. The positive or negative sign of the adjustment factor indicates whether the voltage is leading or lagging.

[0017] As a further aspect of the present invention, based on the real-time voltage deviation, a corresponding pole-phase group rearrangement scheme is called from a preset parallel branch connection strategy library, including:

[0018] The pole phase rearrangement scheme includes dividing each pole and each phase stator coil into three pole phase groups with equal potential amplitudes and connected in a preset order, and setting the parallel loop lead-out point in the middle of each phase winding in a physical structure configuration.

[0019] The current reactive power output direction of the synchronous condenser is determined based on the polarity of the adjustment factor. If it is an inductive reactive power output, it is determined to be an advancing phase operation condition.

[0020] The parallel branch connection strategy library is used to retrieve a pole phase group rearrangement scheme that matches the leading phase operating condition. The pole phase group rearrangement scheme defines the potential vector phase relationship of the three pole phase groups.

[0021] According to the potential vector phase relationship, the equivalent circuit topology of the stator winding is reconstructed in the control model so that the potential imbalance between the three-phase parallel branches is limited to within the preset imbalance tolerance.

[0022] By adjusting and linking the lead-out positions to the middle node of each phase winding, the interphase sloping potential caused by the branch potential difference is eliminated in the equivalent circuit topology, thereby reducing the equivalent voltage stress between the stator end bars.

[0023] As a further aspect of the present invention, the step of calculating the magnetic flux density increment at the end structure based on the current phase advance operating depth of the condenser includes:

[0024] The magnetic flux density increment is the difference between the actual magnetic flux density during phase advance operation and the magnetic flux density under rated operating conditions;

[0025] The current phase advance operating depth of the phase advance camera is quantified based on the absolute value of the adjustment factor. The larger the phase advance operating depth, the smaller the excitation current.

[0026] The unloaded magnetic field distribution data of the phase shifter under the design conditions is retrieved, and combined with the current phase advance operating depth, the additional magnetic field strength in the end region is calculated by the principle of magnetic field superposition.

[0027] The additional magnetic field strength is added to the end magnetic flux density under the design conditions to obtain the actual end magnetic flux density during phase advance operation;

[0028] The difference between the actual magnetic flux density at the end and the magnetic flux density at the end under the design conditions is the magnetic flux density increment at the end structure.

[0029] As a further aspect of the present invention, when the magnetic flux density increment exceeds a preset temperature rise intervention threshold, the end magnetic circuit optimization control logic is activated, including:

[0030] Compare the magnetic flux density increment with the preset temperature rise intervention threshold;

[0031] If the magnetic flux density increment is greater than the temperature rise intervention threshold, the magnetic shielding simulation module is enabled in the control strategy to simulate the effect of increasing the magnetic resistance at various points at the end by adjusting the relative permeability parameter of the end material.

[0032] At the same time, the electromagnetic property parameters of the pressure ring and pressure finger are modified to the property values ​​of antimagnetic steel to reduce the penetration density of magnetic lines of force in the structural components.

[0033] In addition, an equivalent discrete impedance element is introduced into the tooth model of the stepped plate, and the eddy current loss is reduced by changing the eddy current path of the tooth until the calculated end estimated loss is reduced to within the allowable range.

[0034] As a further aspect of the present invention, the step of calculating the end potential gradient based on the magnetic flux density increment includes:

[0035] The end potential gradient characterizes the potential difference level between the end structural components;

[0036] The scalar potential distribution in the end region is solved using the Poisson equation, and the solution process takes into account the boundary conditions of the stator core, end windings, and end structural components.

[0037] The potential values ​​of adjacent structural components are extracted from the obtained scalar potential distribution. The adjacent structural components include positioning ribs and the back of the punch, ventilation channel steel and pressure fingers.

[0038] The difference between the surface potential values ​​of adjacent structural components is calculated, and the difference is spatially differentiated to obtain the end potential gradient, which characterizes the end electric field strength.

[0039] As a further aspect of the present invention, when the end potential gradient exceeds a preset circulating current blocking threshold, the end circuit blocking control logic is activated, including:

[0040] Determine whether the end potential gradient is greater than a preset circulating current blocking threshold;

[0041] If so, construct an equivalent capacitance model of the insulating sleeve in the control model and connect it in series on the conduction path between the end of the positioning rib and the punch to block the high-frequency discharge channel.

[0042] The electrical connection at both ends of the positioning rib is set to a conductive state, forming a closed low-impedance loop, which forces the induced current in the positioning rib to flow only within the closed loop.

[0043] Virtual segmented insulation barriers are set on both sides of the end core section and magnetic shield to cut off the large current loop formed between the ventilation channel steel and the pressure finger and the lamination, thereby guiding and limiting the flow path of the circulating current.

[0044] As a further aspect of the present invention, the coupling of the output parameters of the activated end magnetic circuit optimization control logic and the end circuit blocking control logic with the pole phase group rearrangement scheme includes:

[0045] The loss suppression coefficient of the end magnetic circuit optimization control logic output and the circulating current suppression coefficient of the end circuit blocking control logic output are summarized.

[0046] The loss suppression coefficient and the circulating current suppression coefficient are weighted and superimposed onto the branch reactance parameters of the pole phase group rearrangement scheme to form a corrected equivalent branch impedance matrix.

[0047] Based on the corrected equivalent branch impedance matrix, the current flow direction of the three-phase parallel branches is redistributed, making the distribution of reactive power among the three branches more balanced, while offsetting the adverse effects of end heating and circulating current.

[0048] As a further aspect of the present invention, the generation of dynamic reactive power allocation instructions for the synchronous condenser under the current operating conditions includes:

[0049] Read the impedance values ​​of each branch in the corrected equivalent branch impedance matrix;

[0050] Based on the current real-time voltage deviation, the reactive current adjustment required for each branch to achieve voltage balance is calculated.

[0051] The reactive current adjustment of each branch is converted into a corresponding excitation current fine-tuning command, which includes the amplitude change and the phase compensation angle.

[0052] The excitation current fine-tuning command is sent to the excitation regulator of the synchronous condenser to complete a closed-loop iteration of dynamic reactive power control.

[0053] As a further aspect of the present invention, the present invention also includes a dynamic reactive power control system based on a synchronous condenser, the system including a memory, a processor, and a computer program stored in the memory and running on the processor, wherein when the processor executes the computer program, it implements the steps of the dynamic reactive power control method based on a synchronous condenser as described above.

[0054] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0055] The magnetic flux density increment of the end structure is calculated based on the current phase advance operating depth of the synchronous condenser. When the magnetic flux density increment exceeds the preset temperature rise intervention threshold, a simulated magnetic shielding structure is applied in the control strategy to increase the end magnetic reluctance. The material properties of the pressure ring and pressure finger are set to antimagnetic steel to further increase the magnetic reluctance of the structure. An equivalent slotted impedance is introduced into the teeth of the stepped plate to reduce eddy current losses. By simulating the magnetic shielding structure and setting the antimagnetic steel material properties, the end magnetic reluctance can be effectively increased, the concentration of magnetic flux at the end can be reduced, and thus the magnetic flux density increment can be reduced. The equivalent slotted impedance of the teeth can suppress the generation and flow of eddy currents, reduce eddy current losses, and prevent the end structure from overheating due to excessive magnetic flux density increment and excessive eddy current losses. This extends the service life of the end structure and improves the thermal stability of the synchronous condenser during phase advance operation.

[0056] Based on the aforementioned magnetic flux density increment, the end potential gradient is calculated. When the end potential gradient exceeds the preset circulating current blocking threshold, an equivalent insulating sleeve model is inserted between the end of the positioning rib and the lamination to isolate the discharge channel. The positioning rib is set to a short-circuited state to provide a path for the circulating current. Equivalent insulating sheets are laid on both sides of the end core section and the magnetic shield to block the relative discharge channels of the ventilation channel steel and the pressure finger. The equivalent insulating sleeve model can effectively isolate the discharge channel between the positioning rib and the lamination, avoiding the occurrence of partial discharge; the short-circuited positioning rib can provide a path for the circulating current, avoiding the circulating current from flowing in other structural components at the end and generating additional losses; the equivalent insulating sheets on both sides of the end core section and the magnetic shield can block the relative discharge channels of the ventilation channel steel and the pressure finger, further suppressing the potential for discharge, reducing circulating current losses, ensuring the operational stability of the phase converter end circuit, and avoiding equipment failures caused by circulating current and discharge. Attached Figure Description

[0057] Figure 1 This is a flowchart of a dynamic reactive power control method based on a synchronous condenser according to the present invention;

[0058] Figure 2 A flowchart for calculating the magnetic flux density increment at the end structure;

[0059] Figure 3 Heat map of magnetic flux density increment distribution at the camera tip;

[0060] Figure 4 A graph showing the quantitative correlation between the advanced operating depth and the end potential gradient;

[0061] Figure 5 Thermographic diagrams were generated to analyze the correlation between end losses and circulation levels at each control stage. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0063] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0064] See Figure 1 The control process begins by acquiring the real-time voltage deviation during the operation of the synchronous condenser. Based on this real-time voltage deviation, a matching pole-phase group rearrangement scheme is retrieved from a pre-set parallel branch connection strategy library. Next, the magnetic flux density increment at the end structure is calculated based on the current phase advance depth of the synchronous condenser. When this magnetic flux density increment exceeds a preset temperature rise intervention threshold, the end magnetic circuit optimization control logic is activated. This logic increases the end magnetic reluctance by simulating the application of a magnetic shielding structure in the control strategy, sets the material properties of the pressure ring and pressure finger to antimagnetic steel to further increase the magnetic reluctance of the structure, and introduces an equivalent slotted impedance in the teeth of the stepped plate to reduce eddy current losses. Simultaneously, the end potential gradient is calculated based on the magnetic flux density increment. When the end potential gradient exceeds a preset circulating current blocking threshold, the end circuit blocking control logic is activated. This logic includes inserting an equivalent insulating sleeve model between the end of the positioning rib and the lamination in the control model to isolate the discharge channel, setting the positioning rib to a short-circuited state to provide a path for the circulating current, and laying equivalent insulating sheets on both sides of the end core section and the magnetic shield to block the relative discharge channels of the ventilation channel steel and the pressure finger. Finally, the output parameters generated by the activated end magnetic circuit optimization control logic and the end circuit blocking control logic are coupled with the pole phase group rearrangement scheme called from the strategy library to generate a dynamic reactive power distribution command for the synchronous condenser under the current operating conditions.

[0065] In one embodiment of the present invention, the instantaneous three-phase voltage values ​​at the synchronous condenser connection point are collected, and the arithmetic mean of the instantaneous three-phase voltage values ​​is calculated as the actual voltage at the grid connection point. The current system nominal voltage setpoint is read from the power grid dispatching system. The actual voltage at the grid connection point is instantaneously compared with the system nominal voltage setpoint to calculate the real-time voltage deviation. The real-time voltage deviation is normalized into an adjustment factor for controlling branch adjustments, where the positive or negative sign of the adjustment factor represents the voltage leading or lagging state. In a specific implementation, a process for obtaining the real-time voltage deviation based on the dynamic reactive power control method of a synchronous condenser is described below with reference to a specific example scenario and data comparison. In an exemplary scenario, a synchronous condenser is connected to the 35kV side bus of a 500kV substation, and the system nominal voltage setpoint of this bus is 35.00kV. At a certain moment, the instantaneous three-phase voltage values ​​collected by the voltage transformer installed at the grid connection point are as follows: Phase A voltage instantaneous value 35.12kV, Phase B voltage instantaneous value 34.85kV, and Phase C voltage instantaneous value 35.23kV. The arithmetic mean of the three-phase voltage instantaneous values ​​is calculated as the actual voltage at the grid connection point, i.e., actual voltage at the grid connection point = (35.12 + 34.85 + 35.23) / 3 = 35.067kV. The current system nominal voltage setpoint is read from the real-time data interface of the power grid dispatching system and confirmed to be 35.00kV. The actual voltage at the grid connection point of 35.067kV is instantaneously compared with the system nominal voltage setpoint of 35.00kV, and the calculated real-time voltage deviation is +0.067kV. In contrast, at another operating moment, the instantaneous values ​​of the three-phase voltages collected may be 34.70kV for phase A, 34.65kV for phase B, and 34.75kV for phase C. At this time, the calculated actual voltage at the grid connection point is 34.70kV. After comparing it with the nominal voltage setting value of 35.00kV for the same system, the real-time voltage deviation is -0.30kV.

[0066] In some embodiments, the process of normalizing the real-time voltage deviation into an adjustment factor for controlling branch adjustments can be implemented following this principle: a reference voltage deviation is set, for example, ±10% of the system nominal voltage setpoint can be defined as the full-scale range of the adjustment factor. For the aforementioned +0.067kV real-time voltage deviation, the normalized adjustment factor is calculated as follows: Adjustment factor = Real-time voltage deviation / Reference voltage deviation. If the reference voltage deviation is taken as 3.5kV, then the adjustment factor = 0.067 / 3.5 ≈ +0.0191. The sign of the adjustment factor directly indicates whether the voltage is leading or lagging. +0.0191 indicates that the actual voltage at the grid connection point is slightly higher than the system nominal voltage setpoint, indicating a slight voltage lead. In contrast, for a -0.30kV real-time voltage deviation, the calculated adjustment factor = -0.30 / 3.5 ≈ -0.0857, with the negative sign clearly indicating a voltage lag. It is understandable that the specific value of the reference voltage deviation can be determined according to different voltage levels and the design specifications of the synchronous condenser control system. For example, ±5% or ±2% of the system's nominal voltage setting value can also be used as the reference.

[0067] In practical implementation, the process of calculating the arithmetic mean of the actual voltage at the grid connection point can optionally be accomplished through a combination of hardware acquisition and software calculation. The analog signal output by the voltage transformer is sampled by a high-precision analog-to-digital converter to obtain a discrete sequence of instantaneous three-phase voltage values. The data processing unit buffers the sampled values ​​for multiple consecutive power frequency cycles, removes abnormal sampling points, and then calculates the effective average value within one cycle using the following formula:

[0068] ,

[0069] in: This represents the calculated actual voltage at the grid connection point. , , These represent the instantaneous voltage values ​​of phases A, B, and C at the k-th sampling point, respectively, where N is the total number of sampling points within one power frequency cycle. This calculation process is performed continuously to ensure the real-time performance of the actual voltage at the grid connection point. The calculated actual voltage at the grid connection point is then instantaneously compared with the system nominal voltage setpoint obtained from the dispatch system data bus under a unified time scale. The real-time voltage deviation is continuously refreshed and output to subsequent control components.

[0070] In one embodiment of the present invention, the current reactive power output direction of the synchronous condenser is determined according to the polarity of the adjustment factor. If it is inductive reactive power output, it is determined to be an advancing phase operation condition. A pole-phase group rearrangement scheme matching the advancing phase operation condition is retrieved from the parallel branch connection strategy library. This scheme defines a physical structure configuration that divides each pole and each phase stator coil into three pole-phase groups with equal potential amplitudes connected in a preset order, and sets the parallel loop lead-out point at the middle position of each phase winding. According to the potential vector phase relationship, the equivalent circuit topology of the stator winding is reconstructed in the control model, so that the potential imbalance between the three-phase parallel branches is limited to within a preset imbalance tolerance. By adjusting the lead-out position of the parallel loop to the middle node of each phase winding, the inter-phase sloping potential caused by the branch potential difference is eliminated in the equivalent circuit topology, thereby reducing the equivalent voltage stress between the stator end bars.

[0071] In practical implementation, the process of calling the corresponding phase group rearrangement scheme from the pre-set parallel branch connection strategy library based on the real-time voltage deviation is described below with specific example scenarios and data comparisons. In one example scenario, assume that the adjustment factor obtained by normalizing the real-time voltage deviation is -0.0857, and its polarity is negative. The current reactive power output direction of the synchronous condenser is determined based on the polarity of the adjustment factor. A negative polarity indicates that the system needs to absorb inductive reactive power to support the voltage, thus determining that the synchronous condenser is in the leading-phase operation condition. The parallel branch connection strategy library stores multiple phase group rearrangement schemes that match different adjustment factor ranges and operating conditions. The system will retrieve all schemes matching the "leading-phase operation condition" tag and select an optimized scheme with a depth of depth corresponding to the specific value of the adjustment factor. The core physical structure configuration of this invoked pole phase rearrangement scheme includes a clear definition: the winding of each pole and each phase stator coil is divided into three coil groups that are symmetrically distributed in space, each coil group is defined as a pole phase group, and the potential amplitude generated by the three pole phase groups is designed to be equal; the scheme also defines the physical connection method of setting the parallel-connected electrical lead-out points at the middle position of the total number of conductors in each phase winding.

[0072] In some embodiments, the invoked pole phase rearrangement scheme defines a specific phase relationship between the potential vectors of the three pole phase groups. For example, it requires that the potential vectors of the three pole phase groups of phase A... , , They are successively separated by a specific phase angle One optional configuration is to make Lag Phase angle , Lag Phase angle Based on this potential vector phase relationship, the equivalent circuit topology of the stator winding is reconstructed in the simulation model of the control system. The equivalent circuit topology represents the three pole phase groups of each phase and their connection relationships using a lumped parameter model. The goal of the reconstruction is to limit the potential imbalance between the parallel branches within each of the three phases A, B, and C to a preset imbalance tolerance. Within, imbalance It can be calculated using the following formula:

[0073] ,

[0074] in: Representing a certain phase The effective value of the potential of each phase group, This represents the average value of the potential of the three phase groups. The control model iteratively adjusts the impedance parameters of the virtual connection points in the equivalent circuit topology to make the calculated... The value is less than the preset tolerance. .

[0075] In practical implementation, the process of reducing the equivalent voltage stress between stator end bars by adjusting the lead-out position of the parallel loop can be optionally implemented in the reconstructed equivalent circuit topology. In the control model, each phase winding is modeled as a distributed parameter network composed of multiple series coil units, and the lead-out point of the parallel loop is set at the middle node of the network, that is, the node where the path impedance is equal when measured from the beginning of the winding as when measured from the end. It can be understood that this setting makes the path impedance of the current flowing from the parallel point to the two parts of the winding theoretically symmetrical in the equivalent circuit topology, thereby eliminating the steady-state potential difference, i.e., the interphase sloping potential, generated between different bars at the stator end due to the potential difference of the parallel branches. In contrast, if the lead-out point of the parallel loop is set at a non-middle position of the winding, such as near the beginning, a significant interphase sloping potential will be observed in the equivalent circuit simulation, resulting in higher equivalent voltage stress on the insulation between the bars. In some embodiments, after completing the topology reconstruction and parameter optimization of the pole phase group rearrangement scheme, the control model will output a set of updated winding connection logic and electrical parameters. This set of parameters is the specific configuration of the pole phase group rearrangement scheme used by the subsequent control links, which matches the current real-time voltage deviation and the leading phase running depth.

[0076] In one embodiment of the present invention, see [reference] Figure 2The current advance operating depth of the condenser is quantified based on the absolute value of the adjustment factor; a larger advance operating depth indicates a smaller excitation current. The no-load magnetic field distribution data of the condenser under design conditions is retrieved, and combined with the current advance operating depth, the additional magnetic field strength in the end region is calculated using the magnetic field superposition principle. This additional magnetic field strength is added to the end magnetic flux density under design conditions to obtain the actual end magnetic flux density during advance operation. The difference between the actual end magnetic flux density and the end magnetic flux density under design conditions is the magnetic flux density increment at the end structural component. The magnitude of this magnetic flux density increment is compared to a preset temperature rise intervention threshold. If the magnetic flux density increment is greater than the temperature rise intervention threshold, the magnetic shielding simulation module is activated in the control strategy. This module simulates increasing the magnetic reluctance at various points at the end by adjusting the relative permeability parameter of the end material. Simultaneously, the electromagnetic property parameters of the pressure ring and pressure finger are modified to the property values ​​of antimagnetic steel to reduce the penetration density of magnetic lines of force in the structural component. In addition, an equivalent discrete impedance element is introduced into the tooth model of the stepped plate, and the eddy current loss is reduced by changing the eddy current path of the tooth until the calculated end estimated loss is reduced to within the allowable range.

[0077] In practical implementation, the process of calculating the magnetic flux density increment at the end structure based on the current phase advance depth of the synchronous condenser and determining whether to activate the end magnetic circuit optimization control logic is described below with specific example scenarios and data comparisons. In one example scenario, assume the absolute value of the adjustment factor obtained from the normalization of the real-time voltage deviation is 0.1. The current phase advance depth of the synchronous condenser is quantified based on the absolute value of the adjustment factor. The phase advance depth and the absolute value of the adjustment factor are positively correlated. One possible mapping relationship is: Phase advance depth is:

[0078] ,

[0079] in: This indicates the quantized depth of the advanced phase. This represents the absolute value of the adjustment factor. This is the proportionality coefficient. When ,Pick At that time, the calculated depth of the advanced phase was obtained. A greater depth of advance in the phase indicates a greater reduction in the excitation current relative to its rated value. This indicates a moderate level of phase advance operation. The no-load magnetic field distribution data of the synchronous condenser under design conditions is pre-stored in the form of a database or field map file, including the magnetic flux density values ​​at each end position under the design rated excitation, denoted as... Based on the current advanced phase operating depth The additional magnetic field strength in the end region is calculated using the principle of magnetic field superposition. In the calculation, the additional magnetic field strength is assumed to be related to the depth of the advancing phase. The calculated additional magnetic field strength is proportional to the design field strength benchmark. The calculated additional magnetic field strength is then converted into an increase in magnetic flux density. and the end magnetic flux density under design conditions Adding them together yields the actual end magnetic flux density during phase advance operation. ,Right now The actual magnetic flux density at the end End magnetic flux density under design conditions The difference obtained by subtracting the two values ​​is the magnetic flux density increment at the end structure. .

[0080] In some embodiments, the magnetic flux density increment is compared with a preset temperature rise intervention threshold to determine whether to activate the end magnetic circuit optimization control logic. The preset temperature rise intervention threshold is a magnetic flux density limit set based on the material's heat resistance level and cooling conditions. If the calculated magnetic flux density increment Greater than the temperature rise intervention threshold If this is the case, the magnetic shielding simulation module is enabled in the control strategy. The magnetic shielding simulation module simulates the effect of actually adding a magnetic shielding structure to increase the magnetic reluctance at various points on the end by adjusting the relative permeability parameters of relevant materials in the finite element model or equivalent magnetic circuit model of the end region, reducing the relative permeability from its initial value to a smaller value. It can be understood that modifying the permeability parameters directly changes the distribution path and concentration of magnetic field lines in the simulation model.

[0081] In specific implementation, activating the end magnetic circuit optimization control logic also includes modifying the electromagnetic property parameters of the pressure ring and pressure finger. An optional implementation is to change the material corresponding to the pressure ring and pressure finger from the original structural steel to antimagnetic steel in the material property library. The relative permeability of antimagnetic steel is close to 1, much lower than that of ordinary structural steel. This modification directly manifests in the simulation as a significant increase in the magnetic reluctance of the area where the pressure ring and pressure finger are located, thereby reducing the penetration density of magnetic lines of force in these structural components and reducing iron losses caused by alternating magnetic flux in these parts. Furthermore, an equivalent discrete impedance element is introduced into the tooth model of the stepped plate. One implementation involves connecting a parallel resistive-inductive network in series along the path of the equivalent circuit of the tooth. The impedance value of this network is calculated and set to simulate the additional impedance introduced by the tooth slotting. It can be understood that introducing this equivalent discrete impedance element changes the boundary conditions and flow path of the eddy current field in the tooth, which can reduce the calculated eddy current loss value in this region during simulation calculations. The control model iteratively adjusts the permeability parameters, antimagnetic steel properties, and discrete impedance element parameters of the magnetic shielding simulation module until the total estimated end loss calculated based on the new model drops to the preset allowable range. At this point, the end magnetic circuit optimization control logic outputs a set of final parameter modification schemes as its control output.

[0082] See Figure 3The figure presents the spatial distribution of magnetic flux density increment in the end region and the temperature rise intervention threshold boundary under the leading-phase operation condition. The horizontal axis represents the axial position (cm) of the end region, and the vertical axis represents the radial position (cm) of the end region. The color scale on the right quantifies the gradient distribution of magnetic flux density increment (T): the blue area represents a lower magnetic flux density increment (below approximately 0.05T), and the red area represents a higher magnetic flux density increment (above approximately 0.30T). Overall, it shows a distribution characteristic of significantly concentrated magnetic flux density increment in the right axial direction and the upper radial direction, which is highly consistent with the physical law of end leakage magnetic field distortion during leading-phase operation. The black curve in the figure marks the temperature rise threshold: 0.25T. This curve is the boundary for determining whether the magnetic flux density increment triggers the end magnetic circuit optimization control logic: if the magnetic flux density increment in the right and upper regions of the curve exceeds 0.25T, control strategies such as magnetic shielding simulation, replacement of antimagnetic steel materials, and equivalent slotted impedance of the teeth need to be activated to increase the end magnetic reluctance and reduce the magnetic flux penetration density and eddy current loss of the structural components; if the magnetic flux density increment in the left and lower regions of the curve does not reach the intervention threshold, maintaining the current magnetic circuit state is sufficient to meet the temperature rise constraint. From the distribution pattern, the magnetic flux density increment gradually increases from the left side (0~4cm) to the right side (7~10cm) in the axial direction, while the radial direction shows a concentrated enhancement trend in the upper middle part (4~8cm). This distribution feature provides an intuitive field basis for accurately locating the end overheating risk area and implementing magnetic circuit optimization and circuit blocking measures in the dynamic reactive power control process. It also verifies the positive correlation between the phase advance operation depth and the end magnetic flux density increment.

[0083] In one embodiment of the present invention, the scalar potential distribution in the end region is solved using the Poisson equation, and the solution process considers the boundary conditions of the stator core, end windings, and end structural components. The potential values ​​of the surfaces of adjacent structural components, including the positioning ribs and the back of the laminations, the ventilation channel steel, and the pressure fingers, are extracted from the obtained scalar potential distribution. The difference between the surface potential values ​​of adjacent structural components is calculated, and the difference is spatially differentiated to obtain the end potential gradient characterizing the end electric field strength. It is determined whether the end potential gradient is greater than a preset circulating current blocking threshold. If so, an equivalent capacitance model of the insulating sleeve is constructed in the control model and connected in series in the conduction path between the end of the positioning rib and the lamination to block the high-frequency discharge channel. The electrical connection at both ends of the positioning rib is set to a conducting state, forming a closed low-impedance loop, forcing the induced current in the positioning rib to flow only within the closed loop. Virtual segmented insulating barriers are set on both sides of the end core section and the magnetic shield to cut off the large current loop formed between the ventilation channel steel and the pressure fingers and laminations, thereby guiding and limiting the flow path of the circulating current.

[0084] In practical implementation, the process involves calculating the end potential gradient based on the magnetic flux density increment and determining whether to activate the end circuit blocking control logic. The calculation of the end potential gradient begins with solving for the scalar potential distribution within the end region using the Poisson equation. The Poisson equation has the following form:

[0085] ,

[0086] in: This represents the scalar potential at a point within the solution domain. This represents the charge density at that point. This represents the dielectric constant of the medium. The solution process is carried out in a two-dimensional or three-dimensional finite element model that includes the stator core ends, end windings, and end structural components. The boundary conditions of the model are set according to the actual operating voltage and ground potential. In an example calculation, a cross-section at the end is solved, and a scalar potential distribution cloud map on that cross-section is obtained.

[0087] In some embodiments, the potential values ​​of adjacent structural component surfaces are extracted from the obtained scalar potential distribution. The adjacent structural components from which potential values ​​need to be extracted include the surface of the positioning rib and the back surface of the adjacent punch, and the surface of the ventilation channel steel and the surface of the adjacent pressure finger. A series of corresponding sampling point pairs are selected in the model, and the potential value of each pair is recorded. The difference between the potential values ​​of each pair of adjacent structural component surfaces is calculated. and the potential difference value By performing spatial differentiation along the normal direction of the structural component surface, the end potential gradient, which characterizes the end electric field intensity, is obtained. The calculation formula is:

[0088] ,

[0089] in: This represents the distance along the surface normal direction. Optionally, refer to Table 1, which shows the potential differences and calculated potential gradients between several groups of adjacent structural components extracted from a single simulation.

[0090] Table 1: Potential differences and calculated potential gradients between several groups of adjacent structural components

[0091]

[0092] Determine whether the end potential gradient is greater than a preset circulating current blocking threshold. This is a safety margin value set based on the withstand voltage strength of the insulation material, for example, it might be set to 6.0 kV / mm. According to the example above, the potential gradient between the positioning rib C and the lamination C... kV / mm, greater than the circulation blocking threshold If the value is kV / mm, the condition is met, and the terminal circuit blocking control logic is activated.

[0093] In practical implementation, activating the end circuit blocking control logic includes constructing an equivalent capacitance model of the insulating sleeve in the control model. This can be understood as using a lumped parameter capacitor. This indicates that, along the electrical connection path between the end of the positioning rib and the back of the lamination, this equivalent capacitance model is connected in series into the circuit. The capacitive reactance exhibits low impedance at high frequencies, thus blocking high-frequency discharge channels that may be formed by rapidly changing potential differences in the simulation. The electrical connection at both ends of the positioning rib is set to a conductive state in the model, i.e., the beginning and end of the positioning rib are connected by a zero-impedance wire, forming a closed low-impedance loop. In the electromagnetic field-circuit coupling simulation, this setting forces the eddy currents induced by the alternating magnetic field in the positioning rib to flow mainly within the short-circuit loop of the positioning rib itself, preventing current from flowing to other components.

[0094] In specific implementation, activating the end circuit blocking control logic also includes setting virtual segmented insulation barriers on both sides of the end core segment and the magnetic shield. An optional implementation involves inserting an extremely thin physical domain with near-zero conductivity between the end core segment laminations and between the magnetic shield and adjacent structural components in the finite element model. In some embodiments, the thickness of this virtual insulation barrier is set to 0.1 mm, and the material properties are defined as an ideal insulator. This setting cuts off the continuous conductive loop that may form between the ventilation channel steel and the pressure finger and the lamination through metal contact in the simulation model, thereby guiding and limiting the flow path of the circulating current, ensuring it flows only in a set, controllable path and preventing the formation of large circulating current loops. The output of the end circuit blocking control logic is the constructed equivalent capacitance value. The set of geometric and material parameters for short-circuit circuit impedance and virtual insulation barrier.

[0095] See Figure 4This paper presents a quantitative correlation between the advance phase operating depth and the end potential gradient, focusing on the core issue of end electric field characteristic control under the advance phase operation condition of the synchronous condenser. The horizontal axis uses the advance phase operating depth (%) as the measurement dimension to characterize the degree of advance phase operation under the excitation current regulation of the synchronous condenser; the vertical axis uses the end potential gradient (kV / mm) as the quantitative indicator to reflect the electric field strength level between end structural components. The solid line in the figure is the measured change trajectory of the simulated potential gradient, the dashed line marks the circulating current blocking threshold of 6.0kV / mm, and the filled area is the blocking logic area that needs to be activated. From the curve evolution pattern, when the advance phase operating depth is in the range of 0%~40%, the end potential gradient remains at a low level (2~4.5kV / mm) and has small fluctuations; when the advance phase operating depth exceeds 40%, the end potential gradient shows a significant upward trend, the fluctuation amplitude gradually narrows but the overall slope increases, and it approaches and exceeds 10kV / mm in the range of 80%~100%. Based on the circulating current blocking threshold determination, after the phase advance depth exceeds about 50%, the simulated potential gradient remains above 6.0 kV / mm. The corresponding pink area is the critical interval where the end circuit blocking control logic needs to be activated. This is highly consistent with the core judgment criterion of "activating circuit blocking logic based on potential gradient" in the dynamic reactive power control method of synchronous condenser. It intuitively reflects the positive correlation between phase advance depth and end electric field risk, and also confirms the necessity of limiting the potential gradient through magnetic circuit optimization, circuit blocking and other means.

[0096] In one embodiment of the present invention, the loss suppression coefficient of the end magnetic circuit optimization control logic output and the circulating current suppression coefficient of the end circuit blocking control logic output are summarized. The loss suppression coefficient and the circulating current suppression coefficient are weighted and superimposed onto the branch reactance parameters of the phase group rearrangement scheme to form a corrected equivalent branch impedance matrix. Based on the corrected equivalent branch impedance matrix, the current flow direction of the three-phase parallel branches is redistributed, making the reactive power distribution among the three branches more balanced, while offsetting the adverse effects of end heating and circulating current. The impedance values ​​of each branch in the corrected equivalent branch impedance matrix are read, and combined with the current real-time voltage deviation, the reactive current adjustment amount required for each branch to achieve voltage balance is calculated. The reactive current adjustment amount of each branch is converted into a corresponding excitation current fine-tuning command, which includes amplitude change and phase compensation angle. The excitation current fine-tuning command is sent to the excitation regulator of the synchronous condenser, completing one closed-loop iteration of dynamic reactive power control.

[0097] In practical implementation, the output parameters of the activated end-field magnetic circuit optimization control logic and the end-field circuit blocking control logic are coupled with the pole-phase group rearrangement scheme to generate dynamic reactive power allocation instructions. This process is described below with specific example scenarios and data comparisons. The loss suppression coefficient output by the end-field magnetic circuit optimization control logic and the circulating current suppression coefficient output by the end-field circuit blocking control logic are summarized. The loss suppression coefficient is a dimensionless scalar. Its value is calculated by the end magnetic circuit optimization control logic based on the adjustment range of material properties and impedance parameters when the allowable loss range is finally reached. The circulating current suppression coefficient is another dimensionless scalar. Its value is calculated by the end circuit blocking control logic based on the degree of change in the equivalent loop impedance caused by the applied insulation and short-circuiting measures. In an example execution, the loss suppression coefficient output by the end magnetic circuit optimization control logic is... The circulating current suppression coefficient of the terminal circuit blocking control logic output is 0.85. The value is 0.70. In some embodiments, the loss suppression coefficient and the circulating current suppression coefficient are weighted and superimposed onto the branch reactance parameters of the pole phase group rearrangement scheme. One optional weighted superposition formula is:

[0098] ,

[0099] in: This indicates the corrected branch reactance value. This represents the original branch reactance value in the polarity rearrangement scheme. and These are the weighting factors for the loss suppression coefficient and the circulating current suppression coefficient, respectively. Assume the original branch reactance Weighting factor , Then the corrected reactance This calculation is performed on the reactance parameters of each phase and branch defined in the phase group rearrangement scheme, ultimately forming a corrected equivalent branch impedance matrix. .

[0100] In practical implementation, the current flow direction of the three-phase parallel branches is redistributed according to the corrected equivalent branch impedance matrix. This process can be understood as occurring within the network solver of the control system. The solver, based on the nodal voltage equations, uses the corrected equivalent branch impedance matrix... The equivalent impedance of the power grid and the system demand corresponding to the real-time voltage deviation are included in the calculation. The goal is to achieve a new equilibrium state for the reactive current components flowing into each parallel branch based on the new impedance relationship. The calculation results show that, under the new equilibrium state, the distribution of reactive power among the three branches is more balanced than before the correction. Furthermore, because the correction of the impedance matrix simulates the effects of end magnetic circuit optimization and circuit blocking, the adverse effects of end heating and circulating current are partially offset in the current distribution calculation. The impedance values ​​of each branch are read from the corrected equivalent branch impedance matrix. ,in Indicates separation, Indicates the branch number. Combined with the current real-time voltage deviation. The reactive current adjustment required for each branch to achieve system voltage balance can be calculated. The calculation process is based on the power equation, and one optional linearization relationship is:

[0101] ,

[0102] in: It depends on the allocation coefficient of the branch's position in the system. Optionally, in a single calculation instance, for the first branch of phase A, if , Distribution coefficient The calculated reactive current adjustment for that branch is then... .

[0103] In some embodiments, the reactive current adjustment of each branch is converted into a corresponding excitation current fine-tuning command, which includes the amplitude change. With phase compensation angle The conversion process is based on the excitation-armature reaction model of the synchronous condenser. The reactive current adjustment of each branch is first synthesized into the total reactive current demand change. Amplitude change and Proportional to the motor's synchronous reactance. Phase compensation angle. This is used to compensate for the internal potential phase shift caused by branch impedance redistribution and changes in end conditions. It can be understood that the final generated excitation current fine-tuning command is a... and A set of two digital commands. The excitation current fine-tuning command is sent to the excitation regulator of the synchronous condenser via fieldbus or hard-wiring. After receiving the command, the excitation regulator adjusts the thyristor firing angle in its next control cycle to change the current of the excitation winding, thereby completing a closed-loop iteration of dynamic reactive power control.

[0104] See Figure 5 This study presents the evolution of three core indicators—end-end loss, circulating current level, and reactive power balance—at different control stages throughout the dynamic reactive power control process of a synchronous condenser. It intuitively reflects the regulatory effects of various control strategies on the electromagnetic characteristics and reactive power distribution at the end-end points. From the perspective of the indicators: End-end loss: Initially 100.0, the value gradually decreases to 45.0 as the phase group rearrangement, magnetic circuit optimization, circuit blocking, impedance correction, current adjustment, and excitation optimization are implemented until stable operation. This reflects the progressive suppression effect of measures such as magnetic circuit optimization (increasing end magnetic reluctance and reducing magnetic penetration of structural components) and circuit blocking (isolating eddy current paths) on end-end heating. The loss attenuation reaches 55%, verifying the effectiveness of the loss suppression strategy. Circulating current level: Initially 95.0, it decreases synchronously to 38.0 as the control stage progresses, showing a strong positive correlation with end-end loss. This indicates that the circuit blocking control logic (inserting insulating sleeves, short-circuiting positioning ribs, and laying insulating sheets) effectively limits the induced circulating current between end structural components, weakening the additional losses caused by the circulating current. Reactive power balance: Initially only 0.6, gradually increasing to 1.0 with each control iteration, reflecting how phase group rearrangement, impedance correction, and dynamic reactive power distribution commands balanced the reactive power distribution of the three-phase branches, ultimately achieving the ideal operating state of "low loss, low circulating current, and high balance." From a stage evolution perspective, the heatmap color gradually transitions from initial dark red (high loss, high circulating current) to light yellow / light blue (low loss, low circulating current), while the reactive power balance column evolves from dark blue to even darker blue, fully depicting the control closed-loop process from initial imbalance to stable optimization: phase group rearrangement first reduces basic losses and circulating current; magnetic circuit optimization and circuit blocking further suppress end effects from magnetic and electrical dimensions, respectively; subsequent impedance correction, current adjustment, and excitation optimization complete refined control, ultimately achieving optimal matching of indicators in the stable operation stage. The heatmap provides a quantitative and visual basis for verifying the effectiveness of the synchronous condenser's dynamic reactive power control strategy, and can be used to evaluate the marginal benefits of different control stages, providing data support for parameter optimization and strategy iteration.

[0105] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments that can be applied to other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A dynamic reactive power control method based on a synchronous condenser, characterized in that, include: Obtain the real-time voltage deviation during synchronous condenser operation, and based on the real-time voltage deviation, call the corresponding pole phase group rearrangement scheme from the preset parallel branch connection strategy library; Based on the current advance operating depth of the condenser, the magnetic flux density increment at the end structure is calculated. When the magnetic flux density increment exceeds the preset temperature rise intervention threshold, the end magnetic circuit optimization control logic is activated. The end magnetic circuit optimization control logic includes: simulating the application of a magnetic shielding structure in the control strategy to increase the end magnetic reluctance, setting the material properties of the pressure ring and pressure finger to antimagnetic steel to increase the magnetic reluctance of the structure, and introducing an equivalent slotted impedance in the teeth of the stepped plate to reduce eddy current loss. Simultaneously, the end potential gradient is calculated based on the magnetic flux density increment. When the end potential gradient exceeds the preset circulating current blocking threshold, the end circuit blocking control logic is activated. The end circuit blocking control logic includes: inserting an equivalent insulating sleeve model between the end of the positioning rib and the punch to block the discharge channel; setting the positioning rib to a short-circuited state to provide a path for the circulating current; and laying equivalent insulating sheets on both sides of the end core section and the magnetic shield to block the relative discharge channels of the ventilation channel steel and the pressure finger. The output parameters of the activated end magnetic circuit optimization control logic and the end circuit blocking control logic are coupled with the pole phase group rearrangement scheme to generate the dynamic reactive power distribution command of the synchronous condenser under the current operating conditions.

2. The dynamic reactive power control method based on a synchronous condenser according to claim 1, characterized in that, The acquisition of the real-time voltage deviation during synchronous condenser operation includes: The real-time voltage deviation is determined by the instantaneous difference between the actual voltage at the grid connection point and the nominal voltage of the system. Collect the instantaneous three-phase voltage values ​​at the synchronous condenser connection point and calculate the arithmetic mean of the instantaneous three-phase voltage values ​​as the actual voltage at the grid connection point; Read the current system nominal voltage setting value from the power grid dispatching system; The actual voltage at the grid connection point is instantaneously compared with the nominal voltage setting value of the system to calculate the real-time voltage deviation. The real-time voltage deviation is normalized into an adjustment factor for controlling branch adjustment. The positive or negative sign of the adjustment factor indicates whether the voltage is leading or lagging.

3. The dynamic reactive power control method based on a synchronous condenser according to claim 2, characterized in that, Based on the real-time voltage deviation, the corresponding pole-phase group rearrangement scheme is called from the preset parallel branch connection strategy library, including: The pole phase rearrangement scheme includes dividing each pole and each phase stator coil into three pole phase groups with equal potential amplitudes and connected in a preset order, and setting the parallel loop lead-out point in the middle of each phase winding in a physical structure configuration. The current reactive power output direction of the synchronous condenser is determined based on the polarity of the adjustment factor. If it is an inductive reactive power output, it is determined to be an advancing phase operation condition. The parallel branch connection strategy library is used to retrieve a pole phase group rearrangement scheme that matches the leading phase operating condition. The pole phase group rearrangement scheme defines the potential vector phase relationship of the three pole phase groups. According to the potential vector phase relationship, the equivalent circuit topology of the stator winding is reconstructed in the control model so that the potential imbalance between the three-phase parallel branches is limited to within the preset imbalance tolerance. By adjusting and linking the lead-out positions to the middle node of each phase winding, the interphase sloping potential caused by the branch potential difference is eliminated in the equivalent circuit topology, thereby reducing the equivalent voltage stress between the stator end bars.

4. The dynamic reactive power control method based on a synchronous condenser according to claim 3, characterized in that, The calculation of the magnetic flux density increment at the end structure based on the current phase advance depth of the condenser includes: The magnetic flux density increment is the difference between the actual magnetic flux density during phase advance operation and the magnetic flux density under rated operating conditions; The current phase advance operating depth of the phase advance camera is quantified based on the absolute value of the adjustment factor. The larger the phase advance operating depth, the smaller the excitation current. The unloaded magnetic field distribution data of the phase shifter under the design conditions is retrieved, and combined with the current phase advance operating depth, the additional magnetic field strength in the end region is calculated by the principle of magnetic field superposition. The additional magnetic field strength is added to the end magnetic flux density under the design conditions to obtain the actual end magnetic flux density during phase advance operation; The difference between the actual magnetic flux density at the end and the magnetic flux density at the end under the design conditions is the magnetic flux density increment at the end structure.

5. The dynamic reactive power control method based on a synchronous condenser according to claim 4, characterized in that, When the magnetic flux density increment exceeds a preset temperature rise intervention threshold, the end magnetic circuit optimization control logic is activated, including: Compare the magnetic flux density increment with the preset temperature rise intervention threshold; If the magnetic flux density increment is greater than the temperature rise intervention threshold, the magnetic shielding simulation module is enabled in the control strategy to simulate the effect of increasing the magnetic resistance at various points at the end by adjusting the relative permeability parameter of the end material. At the same time, the electromagnetic property parameters of the pressure ring and pressure finger are modified to the property values ​​of antimagnetic steel to reduce the penetration density of magnetic lines of force in the structural components. In addition, an equivalent discrete impedance element is introduced into the tooth model of the stepped plate, and the eddy current loss is reduced by changing the eddy current path of the tooth until the calculated end estimated loss is reduced to within the allowable range.

6. The dynamic reactive power control method based on a synchronous condenser according to claim 5, characterized in that, The calculation of the end potential gradient based on the magnetic flux density increment includes: The end potential gradient characterizes the potential difference level between the end structural components; The scalar potential distribution in the end region is solved using the Poisson equation, and the solution process takes into account the boundary conditions of the stator core, end windings and end structural components. The potential values ​​of adjacent structural components are extracted from the obtained scalar potential distribution. The adjacent structural components include positioning ribs and the back of the punch, ventilation channel steel and pressure fingers. The difference between the surface potential values ​​of adjacent structural components is calculated, and the difference is spatially differentiated to obtain the end potential gradient, which characterizes the end electric field strength.

7. The dynamic reactive power control method based on a synchronous condenser according to claim 6, characterized in that, When the end potential gradient exceeds a preset circulating current blocking threshold, the end circuit blocking control logic is activated, including: Determine whether the end potential gradient is greater than a preset circulating current blocking threshold; If so, construct an equivalent capacitance model of the insulating sleeve in the control model and connect it in series on the conduction path between the end of the positioning rib and the punch to block the high-frequency discharge channel. The electrical connection at both ends of the positioning rib is set to a conductive state, forming a closed low-impedance loop, which forces the induced current in the positioning rib to flow only within the closed loop. Virtual segmented insulation barriers are set on both sides of the end core section and magnetic shield to cut off the large current loop formed between the ventilation channel steel and the pressure finger and the lamination, thereby guiding and limiting the flow path of the circulating current.

8. The dynamic reactive power control method based on a synchronous condenser according to claim 7, characterized in that, The coupling of the output parameters of the activated end magnetic circuit optimization control logic and the end circuit blocking control logic with the pole phase rearrangement scheme includes: The loss suppression coefficient of the end magnetic circuit optimization control logic output and the circulating current suppression coefficient of the end circuit blocking control logic output are summarized. The loss suppression coefficient and the circulating current suppression coefficient are weighted and superimposed onto the branch reactance parameters of the pole phase group rearrangement scheme to form a corrected equivalent branch impedance matrix. Based on the corrected equivalent branch impedance matrix, the current flow direction of the three-phase parallel branches is redistributed, making the distribution of reactive power among the three branches more balanced, while offsetting the adverse effects of end heating and circulating current.

9. The dynamic reactive power control method based on a synchronous condenser according to claim 8, characterized in that, The dynamic reactive power allocation command for the synchronous condenser under the current operating conditions includes: Read the impedance values ​​of each branch in the corrected equivalent branch impedance matrix; Based on the current real-time voltage deviation, the reactive current adjustment required for each branch to achieve voltage balance is calculated. The reactive current adjustment of each branch is converted into a corresponding excitation current fine-tuning command, which includes the amplitude change and the phase compensation angle. The excitation current fine-tuning command is sent to the excitation regulator of the synchronous condenser to complete a closed-loop iteration of dynamic reactive power control.

10. A dynamic reactive power control system based on a synchronous condenser, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the dynamic reactive power control method based on a synchronous condenser as described in any one of claims 1 to 9.

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