Safety control method, system, device and medium considering operation boundary of two-axis excitation phase modifier

Abstract

The application discloses a safety control method, system and device considering operation boundary of a two-shaft excitation phase modifier and a medium, relates to the technical field of motor control, and aims to take the insulation limit temperature of each winding as the ultimate constraint, reversely deduce the maximum allowable working current of the winding through a steady-state heat balance relationship; then, based on an electromagnetic transient mathematical model, map the current constraints of three types of windings, i.e., armature windings, excitation windings and damping windings, to an active-reactive power plane at the same time, solve the power limit operation boundary under different rotor speeds, determine the globally safe power regulation range and speed regulation range through the intersection of multi-winding constraints, and finally embed a power regulation constraint module in the control strategy, so that the dispatching target power can be discriminated and corrected in real time in a proportional limit, and the power instruction is ensured to be always within the safe operation boundary of the equipment.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and more specifically to a safety control method, system, device, and medium that takes into account the operating boundary of a dual-axis excitation synchronous condenser. Background Technology

[0002] With the continuous increase in installed capacity of new energy sources, the randomness, volatility, and intermittency of new energy power generation are becoming increasingly apparent, leading to reduced voltage stability and increased risk of frequency exceeding limits in the system. Dual-axis synchronous condensers, with their unique advantages of simultaneously providing voltage and inertia support, are widely used in voltage stabilization and frequency regulation scenarios in grids with a high proportion of new energy sources, effectively compensating for the technical shortcomings of traditional synchronous condensers, which can only regulate reactive power and have insufficient grid frequency regulation inertia.

[0003] However, under the complex operating conditions of actual power grids, dual-axis excitation synchronous condensers need to frequently respond to power dispatch commands from the grid, dynamically adjusting active and reactive power output. Furthermore, the rotor speed fluctuates dynamically during operation, easily leading to excessive operating current and temperature rise in various windings. Current dual-axis excitation synchronous condenser control strategies primarily focus on grid power support, optimizing frequency regulation and voltage stabilization control logic, but neglect the thermal safety constraints of the condenser's armature winding, excitation winding, and damping winding. They fail to clearly define the power safety operating boundaries of the equipment under different speed conditions. They lack a thermal constraint derivation link from insulation limit temperature to the maximum allowable operating current of the windings; they fail to solve for the power limit boundaries of multi-winding coupling under different speed conditions at the electromagnetic transient level; and they lack a feedforward power safety correction mechanism in the control strategy, relying solely on backup protection tripping as a last resort. Once this trips, the condenser disconnects from the grid, exacerbating grid fluctuations.

[0004] Therefore, there is an urgent need for a dual-axis excitation phase shifter safety control method that incorporates the winding thermal safety constraint feedforward into the control strategy and establishes a speed-adaptive power safety boundary. Summary of the Invention

[0005] Based on the problems raised in the background technology, the purpose of this invention is to provide a safety control method, system, device and medium that takes into account the operating boundary of a dual-axis excitation phase shifter, and to solve the problems in the prior art where the dual-axis excitation phase shifter control strategy ignores the thermal safety constraints of the main winding and does not establish a speed adaptive power safety boundary.

[0006] This invention is achieved through the following technical solution: The first aspect of this invention provides a safety control method considering the operating boundary of a dual-axis excitation phase-shifting camera, comprising the following steps: Thermal constraint calculations are performed based on the insulation limit temperature of each winding to obtain the maximum allowable operating current of each winding. Based on the electromagnetic transient mathematical model of the dual-axis excitation phase modulator, and combined with the maximum allowable operating current of each winding, the active power and reactive power limit operating boundaries corresponding to the current constraints of each winding under different rotor speed conditions are solved. Based on the multi-winding constraint intersection judgment principle, the intersection of the power limit operating boundaries of each winding is taken to determine the power safe adjustment range and speed safe adjustment range of the dual-axis excitation synchronous condenser. The system performs limit-crossing detection on the target power issued by the dispatcher. When the target power exceeds the power safety adjustment range, it performs proportional limit correction to constrain the power command to within the safe operating boundary.

[0007] In the above technical solution, firstly, the maximum allowable operating current is calculated in reverse based on the insulation limit temperature of each winding to establish a thermal constraint quantification benchmark; secondly, based on the electromagnetic transient mathematical model of the dual-axis excitation synchronous condenser, the active and reactive power limit boundaries corresponding to the current constraints of each winding are solved under different rotor speed conditions; furthermore, by taking the intersection of the power boundaries of all windings, the overall power safety adjustment range and speed safety adjustment range of the equipment are determined; finally, the target power issued by the dispatcher is judged to exceed the limit. If it exceeds the safe range, a proportional limit correction is performed to ensure that the command always falls within the boundary. This method moves the thermal safety boundary from passive protection action to active control constraint, realizing the coordination and unity between the grid support requirements and the physical limits of the equipment, and effectively ensuring the safe operation of the synchronous condenser.

[0008] In one alternative embodiment, the windings include: an armature winding, a field winding, and a damping winding.

[0009] In one optional embodiment, thermal constraint calculation is performed based on the insulation limit temperature of each winding, including: Establish a corrected relationship between winding resistance and operating temperature; The maximum allowable temperature rise is determined by the difference between the insulation limit temperature of each winding and the ambient reference temperature. Based on the rated steady-state operating conditions, the independent equivalent heat dissipation coefficient of each winding is calibrated. Based on the steady-state thermal balance relationship, the maximum allowable operating current of each winding during long-term operation is calculated from the maximum allowable temperature rise and the winding resistance at the limit temperature after correction by the aforementioned relationship.

[0010] In one optional embodiment, based on the multi-winding constraint intersection determination principle, the intersection of the power limit operating boundaries of each winding is taken to determine the power safety adjustment range of the dual-axis excitation synchronous condenser, including: Calculate the active and reactive power operating boundaries corresponding to the maximum current constraints of the armature winding, excitation winding, and damping winding under synchronous and asynchronous operating conditions, respectively. Under synchronous operation conditions, there is no induced current in the damping winding, and the intersection of the power operating boundaries of the armature winding and the excitation winding is taken as the power safety adjustment range under synchronous operation conditions. Under asynchronous operation, current exists in the armature winding, excitation winding, and damping winding. The intersection of the power operating boundaries of the three types of windings is taken as the power safety adjustment range under asynchronous operation.

[0011] In one optional embodiment, based on the multi-winding constraint intersection determination principle, the intersection of the power limit operating boundaries of each winding is taken to determine the safe adjustment range of the dual-axis excitation synchronous condenser speed, including: Within the asynchronous operation range, based on the dynamic relationship between the power operating boundaries of each winding and the rotor speed deviating from the synchronous speed, the corresponding limit operating speed is determined when the power operating boundaries of any two types of windings are tangent. The minimum and maximum limit speeds corresponding to the boundary tangency are taken to form the full-range safe speed adjustment range of the dual-axis excitation phase modulator.

[0012] In one optional embodiment, the target power issued by the scheduler is judged to exceed the limit. When the target power exceeds the power safety adjustment range, a proportional limiting correction is performed, including: Initial active power reference values ​​and reactive power reference values ​​are generated based on the grid bus frequency and voltage through proportional-integral control. The initial power reference value is compared with the power safety adjustment range. If the limit is exceeded, the power reference value is scaled proportionally to the power safety adjustment boundary based on the power scaling factor. If the limit is not exceeded, the initial power reference value remains unchanged.

[0013] In one optional embodiment, the corrected power reference value is sent to the power outer loop controller to generate a current setpoint. The current setpoint is then processed by the current inner loop controller, which combines the real-time collected excitation current with the estimated damping current feedback to perform proportional-integral adjustment, and outputs the excitation voltage target value.

[0014] A second aspect of the present invention provides a safety control system considering the operating boundaries of a dual-axis excitation phase shifter, comprising: The thermal constraint module is used to perform thermal constraint calculations based on the insulation limit temperature of each winding to obtain the maximum allowable operating current of each winding. The power boundary module is used to solve the active and reactive power limit operating boundaries corresponding to the current constraints of each winding under different rotor speed conditions, based on the electromagnetic transient mathematical model of the dual-axis excitation phase modulator and the maximum allowable operating current of each winding. The adjustment range module is used to determine the safe power adjustment range and safe speed adjustment range of the dual-axis excitation synchronous condenser by taking the intersection of the power limit operating boundaries of each winding based on the multi-winding constraint intersection judgment principle. The power correction module is used to determine whether the target power issued by the schedule exceeds the limit. When the target power exceeds the power safety adjustment range, it performs proportional limit correction to constrain the power command to the safe operating boundary.

[0015] A third aspect of the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements a safety control method that takes into account the operating boundaries of a dual-axis excitation camera.

[0016] A fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements a safety control method taking into account the operating boundaries of a dual-axis excitation camera.

[0017] Compared with the prior art, the present invention has the following advantages and beneficial effects: This invention incorporates a winding thermal safety constraint feedforward control strategy, performing safety verification and correction during the power command generation stage, fundamentally avoiding the risks of winding overcurrent and overtemperature operation. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a grid-connected topology diagram of a dual-axis excitation phase modulator and excitation control system provided in an embodiment of the present invention; Figure 2 This is the power adjustment boundary for synchronous operation of a dual-axis excitation camera provided in an embodiment of the present invention; Figure 3 This invention provides a power adjustment boundary for asynchronous operation of a dual-axis excitation phase-regulating camera in an embodiment of the invention. Figure 4 This is a schematic diagram illustrating the correction of the power reference value of the dual-axis excitation camera provided in an embodiment of the present invention; Figure 5 This is a control block diagram of the dual-axis excitation camera power correction module provided in an embodiment of the present invention; Figure 6 The transient characteristic curves of voltage and inertia support for dual-axis excitation phase modulators when employing a safety control strategy are provided in the embodiments of the present invention. Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention. Example

[0020] Embodiment 1 of the present invention provides a safety control method considering the operating boundary of a dual-axis excitation phase shifter, comprising the following steps: Thermal constraint calculations are performed based on the insulation limit temperature of each winding to obtain the maximum allowable operating current of each winding. Based on the electromagnetic transient mathematical model of the dual-axis excitation phase modulator, and combined with the maximum allowable operating current of each winding, the active power and reactive power limit operating boundaries corresponding to the current constraints of each winding under different rotor speed conditions are solved. Based on the multi-winding constraint intersection judgment principle, the intersection of the power limit operating boundaries of each winding is taken to determine the power safe adjustment range and speed safe adjustment range of the dual-axis excitation synchronous condenser. The system performs limit-crossing detection on the target power issued by the dispatcher. When the target power exceeds the power safety adjustment range, it performs proportional limit correction to constrain the power command to within the safe operating boundary.

[0021] It should be noted that, with the insulation limit temperature of each winding as the ultimate constraint, the maximum allowable operating current of the winding is inversely calculated through the steady-state thermal balance relationship; then, based on the electromagnetic transient mathematical model, the current constraints of each winding are simultaneously mapped to the active-reactive power plane to solve the power limit operating boundary at different rotor speeds; through the intersection judgment of multi-winding constraints, the safe power regulation range and speed regulation range of the entire domain are determined; finally, a power regulation constraint module is embedded in the control strategy to perform real-time over-limit judgment and proportional amplitude correction on the scheduling target power, ensuring that the power command is always within the safe operating boundary of the equipment.

[0022] In this embodiment, each winding includes: armature winding, excitation winding, and damping winding.

[0023] In one optional embodiment, thermal constraint calculation is performed based on the insulation limit temperature of each winding, including: A correction relationship is established for the winding resistance as a function of operating temperature. This correction relationship considers the characteristics of winding resistance variation with operating temperature, using a reference DC resistance at 40°C as a reference, and correcting the resistance based on the real-time winding temperature. Specifically, the correction relationship is as follows: ; In the formula, R 40 This is the reference DC resistance of the winding at 40°C. θ This refers to the actual operating temperature of the winding. R ( θ ) represents the real-time winding resistance at the corresponding temperature.

[0024] The maximum permissible temperature rise is determined by the difference between the insulation limit temperature of each winding and the ambient reference temperature; using the insulation limit temperature of each winding as the upper limit constraint, and combining it with the standard ambient temperature, the difference between the insulation limit temperature of each winding and the ambient reference temperature is taken as the maximum permissible temperature rise. ; In the formula, θ lim The long-term limiting temperature of the winding insulation; θ amb The ambient reference temperature is 40℃; Δ θ allow This represents the maximum permissible temperature rise of the winding.

[0025] Based on rated steady-state operating conditions, the independent equivalent heat dissipation coefficients of each winding are calibrated. Under rated steady-state operating conditions, the heat generated by the winding copper losses is equal to the heat dissipated to the surrounding environment. Based on this, the equivalent heat dissipation coefficients of the armature winding, excitation winding, and damping winding are fitted. Specifically, the resistance is first corrected based on the rated steady-state temperature using a correction relationship. Then, the corrected resistance is fitted with the winding rated current, rated steady-state temperature, and ambient reference temperature to generate the equivalent heat dissipation coefficients of the corresponding windings. ; In the formula, I N This is the rated current of the winding; θ N This is the rated steady-state temperature; K This is the equivalent heat dissipation coefficient for the corresponding winding.

[0026] Among them, since the heat dissipation paths of the armature winding, excitation winding and damping winding are different, the equivalent heat dissipation coefficients are calibrated independently.

[0027] Based on the steady-state thermal balance relationship, the maximum allowable operating current of each winding during long-term operation is calculated from the maximum allowable temperature rise and the winding resistance at the extreme temperature after correction by the aforementioned relationship. The winding resistance at the extreme temperature is then corrected using the correction relationship. According to the steady-state thermal balance relationship, the winding copper loss power equals the heat dissipation power. Substituting the corrected winding resistance at the extreme temperature and the maximum allowable temperature rise into the thermal balance equation, the maximum allowable operating current for each winding during long-term operation is obtained by inverse solution. ; In the formula, I max This is the maximum allowable operating current for the winding over a long period.R ( θ lim ) represents the winding resistance at the extreme temperature.

[0028] By substituting the equivalent heat dissipation coefficients of the armature winding, excitation winding, and damping winding in sequence, the maximum allowable current of the armature winding, the maximum allowable current of the excitation winding, and the maximum allowable current of the damping winding are obtained respectively.

[0029] It should be noted that current technologies typically use rated current or fixed protection thresholds as winding current limits in control strategies. These limits do not consider the actual insulation level of the windings, heat dissipation conditions, and ambient temperature differences. In this embodiment, however, the insulation limit temperature of each winding is used as the ultimate constraint upper limit. Combining the physical characteristics of copper winding resistance changing with temperature and the steady-state thermal balance relationship, the maximum allowable operating current of the armature winding, excitation winding, and damping winding are independently derived. This current limit is the critical current at which the winding just reaches its insulation limit temperature under long-term operation. It has clear physical meaning and individual differences, providing accurate intrinsic safety constraint inputs for subsequent power boundary calculations.

[0030] In one optional embodiment, based on the electromagnetic transient mathematical model of the dual-axis excitation phase modulator, and combined with the maximum allowable operating current of each winding, the active power and reactive power limit operating boundaries corresponding to the current constraints of each winding under different rotor speed conditions are solved: the active power and reactive power operating boundaries corresponding to the maximum current constraints of the armature winding, excitation winding and damping winding are calculated respectively under synchronous operation conditions and asynchronous operation conditions.

[0031] Specifically, the host computer stores the electromagnetic transient mathematical model of the dual-axis excitation phase modulator. This model considers the electromagnetic coupling relationship between the stator winding, the excitation winding, and the damping winding, as well as the influence of the rotor speed on the induced current of the damping winding.

[0032] Under synchronous operation, the rotor speed equals the synchronous speed, and there is no induced current in the damping winding. At this time, the armature current constraint forms a circle centered at the origin (0, 0) on the PQ power plane, with its radius determined by the stator voltage. U s With armature maximum allowable current I smax The product determines: ; In the formula, P The active power generated by the dual-axis excitation phase converter; Q This refers to the reactive power generated by the dual-axis excitation phase shifter.

[0033] The excitation current constraint forms another circle on the PQ plane, with its center at (0, -). Us 2 / X Located on the negative reactive axis, its radius is related to the synchronous reactance, armature reaction reactance, and the maximum allowable excitation current. ; In the formula, X Synchronous reactance; X af Armature reaction reactance; I fmax This represents the maximum value of the excitation current.

[0034] Under asynchronous operation, the rotor speed deviates from the synchronous speed, inducing a current in the damping winding. At this time, the armature current constraint remains a circle centered at the origin (0, 0). ; The excitation current constraint forms a circular center position ( E 1, E 2) The center coordinates and equivalent radius of the circle that varies with slip are related to slip, damping resistance, and damping reactance: ; ; ; ; In the formula, E 1. E 2 represents the x-coordinate and y-coordinate of the center of the boundary circle, respectively; R f It is the equivalent radius of the operating boundary under the excitation current constraint; A , B It reflects intermediate variables; s It is the slip ratio; r D It is a damping resistor; X D It is a damping reactance.

[0035] The damping current constraint forms a third circle, the center of which and its equivalent radius are also related to the slip: ; ; In the formula, R D The equivalent radius of the operating boundary under damped current constraint; I Dmax This represents the maximum value of the damping current.

[0036] By changing the slip value and repeating the above calculation, the power safety adjustment range for asynchronous operation under different speed conditions can be obtained.

[0037] In one optional embodiment, under synchronous operation, the damping winding has no induced current, and the intersection of the power operating boundaries of the armature winding and the excitation winding is taken as the power safety adjustment range of the synchronous operation, that is, the intersection of the armature and the excitation constraint circle is taken as the power safety adjustment range of the synchronous operation, so as to maintain the synchronous speed.

[0038] Under asynchronous operation, current exists in the armature winding, excitation winding, and damping winding. The intersection of the power operating boundaries of the three types of windings is taken as the power safety adjustment range under asynchronous operation. That is, the intersection area of ​​the three circles of armature current constraint, excitation current constraint, and damping current constraint is taken as the power safety adjustment range under the slip rate.

[0039] It should be noted that current technologies only divide reactive power into regions under the synchronous steady-state assumption, and their power boundaries do not involve the active power dimension, nor do they consider speed fluctuations; or, although dynamic speed adjustment is achieved to release inertia, there is a lack of quantitative constraints on the safety boundary between the speed adjustment process and the power output capability. When the speed decreases, the induced current in the damping winding increases, but the controller has no ability to predict this. This results in the synchronous condenser being unable to predict and limit the risk of excessive current in the damping winding caused by the decrease in speed when providing inertia support, and the grid support effect and the thermal tolerance limit of the equipment are in a long-term disconnect. In this embodiment, based on the electromagnetic transient mathematical model of the dual-axis excitation synchronous condenser, power operating boundary equations are established for synchronous and asynchronous operation conditions, respectively, and the maximum allowable operating current of the armature winding, excitation winding and damping winding are mapped to circular boundaries on the active-reactive power plane. Among them, there is no induced current in the damping winding during synchronous operation, and the power boundary is determined by the constraints of the armature and excitation windings; during asynchronous operation, there is current in all three types of windings, and the power boundary is jointly determined by the three types of windings. Furthermore, each boundary changes dynamically with the rotor speed, thus establishing a quantitative mapping relationship between speed and power safety capability.

[0040] In one optional embodiment, based on the multi-winding constraint intersection determination principle, the intersection of the power limit operating boundaries of each winding is taken to determine the safe adjustment range of the dual-axis excitation synchronous condenser speed, including: Within the asynchronous operation range, based on the dynamic relationship between the power operating boundaries of each winding and the rotor speed deviating from the synchronous speed, the corresponding limiting operating speed is determined when the power operating boundaries of any two types of windings are tangent; when any two types of constraint circles are exactly tangent, the intersection region shrinks to a tangent point, and the slip rate corresponding to this point is the limiting slip rate.

[0041] The minimum and maximum limiting speeds corresponding to the boundary tangency are used to form the full-range safe speed adjustment range for the dual-axis excitation phase shifter; the minimum speed corresponding to the boundary tangency is the minimum safe speed. n min The maximum speed is the maximum safe speed. n max This determines the full-range safe speed adjustment range of the dual-axis excitation phase shifter. n min , n max ].

[0042] At the same time, the power safety adjustment range under synchronous and various asynchronous operating conditions is summarized to form a power safety adjustment range database covering the entire speed range, which can be called in real time by the power adjustment constraint module in the host computer.

[0043] It should be noted that this embodiment is the first to clearly define the upper and lower safety boundaries for the rotor speed to deviate from the synchronous speed when providing inertia support in a dual-axis excitation synchronous condenser, filling the gap in the existing technology regarding the safety boundaries of speed-power coupling. Using the multi-winding constraint intersection determination principle, under synchronous operation, the intersection of the power operating boundaries of the armature winding and the excitation winding is taken as the safe power adjustment range of the entire machine; under asynchronous operation, the intersection of the power operating boundaries of the armature, excitation, and damping windings is taken as the safe power adjustment range of the entire machine. This intersection represents the feasible power domain that simultaneously satisfies the thermal safety constraints of all windings, and is a necessary and sufficient condition for the safe operation of the equipment across its entire range.

[0044] In one optional embodiment, the target power issued by the scheduler is judged to exceed the limit. When the target power exceeds the power safety adjustment range, a proportional limiting correction is performed, including: The initial active power reference value is generated based on the grid bus frequency and voltage through proportional-integral control. P ref 'Reactive power reference value' Q ref '; The initial power reference value is compared with the power safety adjustment range. If the range is exceeded, the power reference value is scaled proportionally to the power safety adjustment boundary based on the power scaling factor. ; ; ; In the formula, This is the power scaling factor; F This is the power adjustment boundary for a dual-axis excitation phase shifter.

[0045] If the limit is not exceeded, the initial power reference value remains unchanged.

[0046] The dynamically corrected active and reactive power reference commands are sent to the outer power control loop. The outer loop controller, based on the difference between the measured power and the corrected reference value, performs proportional-integral regulation and outputs a given signal of the sum of the excitation current and the damping current. This current given signal is then input to the inner current controller. The inner loop controller, combining the real-time collected excitation current and the estimated damping current feedback, quickly eliminates the current steady-state error and outputs the excitation voltage target value that meets the requirements of safe unit operation and system regulation after proportional-integral regulation.

[0047] It should be noted that the control strategy of the existing technology takes the grid dispatch demand as the direct instruction. After the power reference value is generated, it directly enters the closed-loop control and lacks real-time verification of the safety boundary of the equipment itself. When the winding current exceeds the limit, it can only trip through the action of independent backup protection devices (such as overcurrent relays and temperature relays), which is a passive protection after the fact.

[0048] This embodiment first checks the target power for over-limit before the power command enters the outer-loop power controller. If the target power is within the power safety regulation range, it is executed directly; if it exceeds the limit, a proportional scaling correction is performed, that is, the over-limit power is scaled proportionally to the power safety boundary according to the power scaling factor. This proportional scaling maintains the ratio between active and reactive power, preserving the directionality of grid power support to the greatest extent while prioritizing the thermal safety of the equipment. This process transforms the thermal safety constraint from backup protection to feedforward correction, realizing closed-loop coupling between the control strategy and the physical limits of the equipment.

[0049] Furthermore, in this embodiment, an independent H-bridge is configured for each of the d-axis and q-axis excitation windings of the dual-axis excitation phase converter. The excitation control system first obtains the target values ​​of the d-axis and q-axis excitation voltages, and then uses SPWM modulation to output the excitation voltage, thereby achieving smooth adjustment of the excitation voltage amplitude and frequency. This ensures that the power adjustment range of the dual-axis excitation phase converter is within the safe operating range, taking into account both the adjustment capability and the safe and stable operation of the unit itself.

[0050] To illustrate the advantages and beneficial effects of the method provided in this embodiment, this embodiment uses a 10.5kV, 50Mvar dual-axis excitation phase converter as an example for the instruction manual.

[0051] Specifically, its grid topology is as follows: Figure 1As shown, the stator three-phase windings of the dual-axis excitation synchronous condenser are connected to the grid via a step-up transformer to provide voltage and inertia support for the power grid. The three-phase AC power from the bus is converted to DC by a step-down transformer and a three-phase rectifier, and then fed into the d-axis and q-axis excitation windings of the dual-axis excitation synchronous condenser through two H-bridge converters. The reference values ​​of the d-axis and q-axis excitation voltages obtained from the control strategy are used by the PWM module to obtain the control signals for the H-bridge, realizing smooth adjustment of the amplitude and frequency of the d-axis and q-axis excitation voltages.

[0052] Based on the electromagnetic transient mathematical model, the power regulation boundary during synchronous operation is calculated as follows: Figure 2 As shown in the figure, the circle includes the stator current constraint boundary and the circle includes the excitation current constraint boundary. The intersection of the two is the power safety regulation range under synchronous operation.

[0053] The power regulation boundary for asynchronous operation (taking a slip of 0.07 as an example) is as follows: Figure 3 As shown, the boundaries of the dual-axis excitation phase converter under current constraints are all circles, and the intersection area of ​​the three circles is the power safety adjustment range under this slip rate.

[0054] Furthermore, as the slip increases, the operating boundary of the damping winding gradually moves downward until it is tangent to the operating boundary of the armature winding or the excitation winding. When the slip reaches 0.086, the two circles are tangent, and the intersection area disappears. The corresponding speed regulation range is 1371 rpm to 1629 rpm, which is the safe speed regulation range of the entire range.

[0055] The correction method for power reference values ​​is as follows: Figure 4 As shown, the power correction module is as follows Figure 5 As shown, the initial active power reference value is first obtained from the system bus voltage and frequency through a PI controller. P ref and reactive power reference value Q ref When the power regulation range is exceeded, the value is scaled proportionally to the operating boundary to obtain a corrected active power reference value. P ref 'and reactive power reference value' Q ref '.

[0056] To verify that the proposed safety control strategy can effectively balance grid regulation performance and the safe operation of the motor itself, the active and reactive power, as well as the stator and rotor currents of the dual-axis excitation synchronous condenser were compared when both voltage and inertia support were applied simultaneously. For example, when the proposed control strategy and the conventional control strategy were used respectively. Figure 6As shown in the diagram, when using the conventional control strategy, the dual-axis excitation synchronous condenser delivers a transient active power of 0.68 pu and a transient reactive power of 0.93 pu. However, the armature current, excitation current, and damping current of the dual-axis excitation synchronous condenser are 1.59 pu, 2.17 pu, and 0.14 pu, respectively. This indicates that while it adequately meets the grid's support requirements, the armature current and excitation current are too high, which is detrimental to the stable operation of the dual-axis excitation synchronous condenser. When the safety control strategy is adopted, the transient active power is corrected to 0.52 pu, the reactive power to 0.43 pu, and the armature current, excitation current, and damping current to 0.75 pu, 1.26 pu, and 0.08 pu, respectively. This shows that while the proposed safety control strategy slightly reduces the grid support capability, the currents in each winding are below the maximum allowable value, balancing grid support capability with the long-term safe operation of the dual-axis excitation synchronous condenser, effectively avoiding adverse effects such as winding overheating and insulation aging. Example

[0057] Embodiment 2 of the present invention provides a safety control system that takes into account the operating boundary of a dual-axis excitation phase shifter, including: The thermal constraint module is used to perform thermal constraint calculations based on the insulation limit temperature of each winding to obtain the maximum allowable operating current of each winding. The power boundary module is used to solve the active and reactive power limit operating boundaries corresponding to the current constraints of each winding under different rotor speed conditions, based on the electromagnetic transient mathematical model of the dual-axis excitation phase modulator and the maximum allowable operating current of each winding. The adjustment range module is used to determine the safe power adjustment range and safe speed adjustment range of the dual-axis excitation synchronous condenser by taking the intersection of the power limit operating boundaries of each winding based on the multi-winding constraint intersection judgment principle. The power correction module is used to determine whether the target power issued by the schedule exceeds the limit. When the target power exceeds the power safety adjustment range, it performs proportional limit correction to constrain the power command to the safe operating boundary. Example

[0058] Figure 7 This is a schematic diagram of the structure of an electronic device provided in Embodiment 3 of the present invention, as shown below. Figure 7 As shown, the electronic device includes a processor 21, a memory 22, an input device 23, and an output device 24; the number of processors 21 in the computer device can be one or more. Figure 7 Taking a processor 21 as an example; the processor 21, memory 22, input device 23, and output device 24 in an electronic device can be connected via a bus or other means. Figure 7 Taking the example of a connection between China and Israel via a bus.

[0059] The memory 22, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules. The processor 21 executes various functional applications and data processing of the electronic device by running the software programs, instructions, and modules stored in the memory 22, thereby implementing the safety control method of Embodiment 1 that takes into account the operating boundaries of the dual-axis excitation camera.

[0060] The memory 22 may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a given function; the data storage area may store data created based on terminal usage. Furthermore, the memory 22 may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory, or other non-volatile solid-state storage device. In some instances, the memory 22 may further include memory remotely located relative to the processor 21, which can be connected to the electronic device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0061] Input device 23 can be used to receive user input such as ID and password. Output device 24 is used to output the network configuration page. Example

[0062] Embodiment 4 of the present invention also provides a computer-readable storage medium, wherein the computer-executable instructions, when executed by a computer processor, are used to implement the safety control method for considering the operating boundary of the dual-axis excitation camera as provided in Embodiment 1.

[0063] The storage medium containing computer-executable instructions provided in the embodiments of the present invention is not limited to the method operation provided in Embodiment 1, but can also perform related operations in the safety control of the operating boundary of the dual-axis excitation camera provided in any embodiment of the present invention.

[0064] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A safety control method considering the operating boundaries of a dual-axis excitation phase shifter, characterized in that, Includes the following steps: Thermal constraint calculations are performed based on the insulation limit temperature of each winding to obtain the maximum allowable operating current of each winding. Based on the electromagnetic transient mathematical model of the dual-axis excitation phase modulator, and combined with the maximum allowable operating current of each winding, the active power and reactive power limit operating boundaries corresponding to the current constraints of each winding under different rotor speed conditions are solved. Based on the multi-winding constraint intersection judgment principle, the intersection of the power limit operating boundaries of each winding is taken to determine the power safe adjustment range and speed safe adjustment range of the dual-axis excitation synchronous condenser. The system performs limit-crossing detection on the target power issued by the dispatcher. When the target power exceeds the power safety adjustment range, it performs proportional limit correction to constrain the power command to within the safe operating boundary.

2. The safety control method considering the operating boundary of a dual-axis excitation phase-shifting camera according to claim 1, characterized in that, The windings include: armature winding, excitation winding, and damping winding.

3. The safety control method considering the operating boundary of a dual-axis excitation camera according to claim 1 or 2, characterized in that, Thermal constraint calculations are performed based on the insulation limit temperature of each winding, including: Establish a corrected relationship between winding resistance and operating temperature; The maximum allowable temperature rise is determined by the difference between the insulation limit temperature of each winding and the ambient reference temperature. Based on the rated steady-state operating conditions, the independent equivalent heat dissipation coefficient of each winding is calibrated. Based on the steady-state thermal balance relationship, the maximum allowable operating current of each winding during long-term operation is calculated from the maximum allowable temperature rise and the winding resistance at the limit temperature after correction by the aforementioned relationship.

4. The safety control method considering the operating boundary of the dual-axis excitation phase-shifting camera according to claim 2, characterized in that, Based on the multi-winding constraint intersection determination principle, the intersection of the power limit operating boundaries of each winding is taken to determine the safe power adjustment range of the dual-axis excitation synchronous condenser, including: Calculate the active and reactive power operating boundaries corresponding to the maximum current constraints of the armature winding, excitation winding, and damping winding under synchronous and asynchronous operating conditions, respectively. Under synchronous operation conditions, there is no induced current in the damping winding, and the intersection of the power operating boundaries of the armature winding and the excitation winding is taken as the power safety adjustment range under synchronous operation conditions. Under asynchronous operation, current exists in the armature winding, excitation winding, and damping winding. The intersection of the power operating boundaries of the three types of windings is taken as the power safety adjustment range under asynchronous operation.

5. The safety control method considering the operating boundary of the dual-axis excitation phase-shifting camera according to claim 4, characterized in that, Based on the multi-winding constraint intersection determination principle, the intersection of the power limit operating boundaries of each winding is taken to determine the safe speed adjustment range of the dual-axis excitation synchronous condenser, including: Within the asynchronous operation range, based on the dynamic relationship between the power operating boundaries of each winding and the rotor speed deviating from the synchronous speed, the corresponding limit operating speed is determined when the power operating boundaries of any two types of windings are tangent. The minimum and maximum limit speeds corresponding to the boundary tangency are taken to form the full-range safe speed adjustment range of the dual-axis excitation phase modulator.

6. The safety control method considering the operating boundary of a dual-axis excitation phase-shifting camera according to claim 1, characterized in that, The system performs limit-crossing detection on the target power issued by the dispatcher. When the target power exceeds the power safety adjustment range, a proportional limiting correction is performed, including: Initial active power reference values ​​and reactive power reference values ​​are generated based on the grid bus frequency and voltage through proportional-integral control. The initial power reference value is compared with the power safety adjustment range. If the limit is exceeded, the power reference value is scaled proportionally to the power safety adjustment boundary based on the power scaling factor. If the limit is not exceeded, the initial power reference value remains unchanged.

7. The safety control method considering the operating boundary of a dual-axis excitation phase-shifting camera according to claim 6, characterized in that, The corrected power reference value is sent to the power outer loop controller to generate the current setpoint. The current setpoint is then processed by the current inner loop controller, which combines the real-time collected excitation current with the estimated damping current feedback to perform proportional-integral adjustment, and outputs the excitation voltage target value.

8. A safety control system considering the operating boundaries of a dual-axis excitation phase shifter, used to implement the safety control method considering the operating boundaries of a dual-axis excitation phase shifter as described in any one of claims 1 to 7, characterized in that, The safety control system includes: The thermal constraint module is used to perform thermal constraint calculations based on the insulation limit temperature of each winding to obtain the maximum allowable operating current of each winding. The power boundary module is used to solve the active and reactive power limit operating boundaries corresponding to the current constraints of each winding under different rotor speed conditions, based on the electromagnetic transient mathematical model of the dual-axis excitation phase modulator and the maximum allowable operating current of each winding. The adjustment range module is used to determine the safe power adjustment range and safe speed adjustment range of the dual-axis excitation synchronous condenser by taking the intersection of the power limit operating boundaries of each winding based on the multi-winding constraint intersection judgment principle. The power correction module is used to determine whether the target power issued by the schedule exceeds the limit. When the target power exceeds the power safety adjustment range, it performs proportional limit correction to constrain the power command to the safe operating boundary.

9. An electronic device, characterized in that, The method includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the safety control method for considering the operating boundary of a dual-axis excitation-adjusting camera as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the safety control method for considering the operating boundary of a dual-axis excitation phase-shifting camera as described in any one of claims 1 to 7.

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