Real-time secondary voltage regulation control method and system for plateau isolated network energy station

Abstract

The invention relates to the technical field of real-time secondary voltage regulation, and provides a plateau isolated network energy station real-time secondary voltage regulation control method, which comprises the following steps: S1, optimizing a voltage value of a measurement point to obtain a bus voltage optimal value as a bus actual voltage; s2, a bus voltage set value is preset, a master station voltage distribution instruction and a dispatching reactive power distribution instruction are calculated according to the bus voltage set value, the actual bus voltage and different operation modes, and the voltage is distributed to all subsystems for adjustment; s3, according to a secondary voltage regulation control strategy, judging the frequency of each measurement point, the power flow of a tie line, the voltage and the switching and stopping of the tie line, obtaining the operation mode of each subsystem, and generating a scheduling AGC / AVC instruction according to a bus voltage set value and a bus actual voltage; and S4, scheduling the AGC / AVC instruction, adjusting the AGC / AVC instruction through the adjustment coefficient of each subsystem, and sending the AGC / AVC instruction to each subsystem for voltage and reactive power adjustment. And high-efficiency, stable and real-time secondary voltage regulation control of the plateau isolated network energy station is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of real-time secondary voltage regulation, and in particular to a real-time secondary voltage regulation control method and system for a plateau isolated grid energy station. Background Art

[0002] In the modern energy supply system, stable voltage is a key factor to ensure the normal operation of various electrical equipment, ensure efficient use of energy, and maintain reliable operation of the system. For industrial production, a stable voltage supply is directly related to the operating efficiency, product quality, and production continuity of production equipment. In the Zabuye Salt Lake lithium extraction project, the production equipment of the lithium carbonate processing plant has extremely high requirements for voltage stability. Voltage fluctuations will not only affect processing efficiency, but may also lead to a decline in product quality and even damage to equipment, resulting in huge economic losses. From the perspective of the overall stability of the energy system, voltage stability is interrelated with frequency stability and power balance and influences each other. When the voltage fluctuates significantly or deviates from the rated value, it may cause an imbalance in the reactive power of the system, which in turn affects the system frequency. In severe cases, it may even cause the power grid to collapse, threatening the safety of the entire energy supply system.

[0003] Among many voltage control methods, secondary voltage regulation control, as a refined and dynamic voltage regulation strategy, plays an irreplaceable role in ensuring the voltage stability of energy systems. It can track the changes in the system's operating status in real time, and respond quickly and accurately to voltage changes caused by factors such as load fluctuations, randomness of renewable energy power generation, and accidental accidents, to ensure that the system voltage is always maintained within a safe and stable range. The implementation of secondary voltage regulation control helps to optimize the reactive power distribution of the energy system, improve the transmission capacity and efficiency of the power grid, and reduce the power loss caused by voltage problems. In the context of widespread access to new energy, such as the large-scale application of solar thermal and photovoltaic systems in the Zabuye Energy Station, secondary voltage regulation control can effectively cope with the intermittent and volatile nature of renewable energy generation, enhance the energy system's ability to absorb new energy, and promote the efficient use of clean energy.

[0004] The secondary voltage regulation control in the prior art has the following deficiencies: (1) It is difficult to maintain bus voltage stability The existing technology cannot effectively maintain the system 35kV bus voltage at a given value in isolated grid energy stations on the plateau. When load fluctuations or accidental accidents occur, the voltage cannot be adjusted accurately in a timely manner, causing the bus voltage to deviate from the given value, affecting the normal operation and power supply quality of the energy station. For example, in the case of a sudden increase in load, the existing technology cannot quickly stabilize the bus voltage within the specified range, causing downstream equipment to fail to work normally due to abnormal voltage.

[0005] (2) Failure to fully consider constraints For the bus voltage control constraints such as the constraints on the bus and generator terminal voltages, the tap positions of on-load tap-changing transformers, and the switching capacity of compensation capacitor banks, the existing technologies fail to comprehensively consider them during secondary voltage regulation control. This may lead to problems such as unreasonable adjustment of the tap positions of transformers and inaccurate switching of compensation capacitor banks during the voltage regulation process, thereby affecting the voltage stability and reactive power balance of the entire system and unable to meet the basic requirements of the real-time secondary voltage regulation function.

[0006] (3) Insufficient response speed and regulation ability Real-time secondary voltage regulation needs to quickly act on the voltage changes caused by load fluctuations or accidental accidents to adjust the generator excitation system, but the existing technologies have obvious defects in this regard. When the voltage changes, the existing technologies cannot quickly respond and make effective adjustments, unable to ensure the transmission of qualified voltage to the power grid and meet the reactive power requirements of the system, resulting in poor adaptability and stability of the system in the face of voltage fluctuations.

[0007] In summary, in the construction of the energy station for lithium extraction from Zabuye Salt Lake, it is of extremely important practical significance to design and implement an efficient and reliable secondary voltage regulation control strategy, which is an inevitable requirement to ensure the stable operation of the energy station, improve energy utilization efficiency, promote the consumption of new energy, and drive the sustainable development of local industries. Summary of the Invention

[0008] Aiming at the above problems, the purpose of the present invention is to provide a real-time secondary voltage regulation control method and system for a high-altitude isolated network energy station, to achieve efficient and stable real-time secondary voltage regulation control of the high-altitude isolated network energy station, so as to ensure the stable power supply and steam supply of the energy station to the lithium carbonate processing plant, and promote the utilization of high-altitude new energy and industrial development.

[0009] The above invention purpose of the present invention is achieved through the following technical solutions: A real-time secondary voltage regulation control method for a high-altitude isolated network energy station includes the following steps: S1: According to the voltage values of several measurement points on the bus collected by the electrical quantity acquisition device, optimize the voltage values of the measurement points based on the power grid topology identification situation, and obtain the preferred value of the bus voltage as the actual bus voltage; S2: Preset the set value of the bus voltage, calculate the main station voltage distribution command and the dispatching reactive power distribution command according to the set value of the bus voltage and the actual bus voltage according to different operation modes, and distribute the voltage to each subsystem for adjustment to form a real-time secondary voltage regulation control strategy; S3: According to the secondary voltage regulation control strategy, comprehensively judge the parameters of each of the measurement points, including frequency, tie-line power flow, voltage, tie-line connection and disconnection, etc., obtain the operation modes of each of the subsystems, and generate a dispatching AGC / AVC instruction according to the bus voltage set value and the actual bus voltage; S4: After being adjusted by the adjustment coefficients of each of the subsystems, the dispatching AGC / AVC instruction is sent to each of the subsystems for voltage and reactive power regulation to maintain voltage stability.

[0010] Further, in step S1, according to the voltage values of several measurement points on the bus collected by the electrical quantity acquisition device, the voltage values of the measurement points are optimized according to the power grid topology identification situation, and the optimized value of the bus voltage is obtained as the actual bus voltage. Specifically: Collect the PT signals on the bus line by the electrical quantity acquisition device, including the voltage values of the measurement points such as the voltage collected by the energy collection station bus, the voltage collected by the solar thermal power station bus, and the voltage collected by the photovoltaic power station bus; When the voltage values are all normal, take the higher voltage value among the voltage collected by the energy collection station bus, the voltage collected by the solar thermal power station bus, and the voltage collected by the photovoltaic power station bus as the optimized value of the bus voltage; When the voltage value of any one of the measurement points fails, obtain the optimized value of the bus voltage in the following order: When the solar thermal unit is operating, obtain the optimized value of the bus voltage in the order of the voltage collected by the energy collection station bus, the voltage collected by the solar thermal power station bus, and the voltage collected by the photovoltaic power station bus. When the solar thermal unit is not operating, obtain the optimized value of the bus voltage in the order of the voltage collected by the energy collection station bus, the voltage collected by the photovoltaic power station bus, and the voltage collected by the solar thermal power station bus.

[0011] Further, in step S2, when the operation mode is solar thermal + solar energy storage and diesel, calculate the main station voltage distribution instruction and the dispatching reactive power distribution instruction, distribute the voltage to each subsystem for regulation, and form a real-time secondary voltage regulation control strategy. Specifically: Obtain the bus voltage set value and the actual bus voltage, and calculate the main station voltage distribution instruction and the dispatching reactive power distribution instruction respectively. Among them, the main station voltage distribution instruction is generated according to the deviation value of the bus voltage set value and the actual bus voltage, combined with the voltage regulation characteristics and control strategy of the system. The main station voltage distribution instruction = Kp × voltage deviation + Ki × ∫ voltage deviation dt, where Kp is the proportional coefficient and Ki is the integral coefficient. The dispatching reactive power distribution instruction is the reactive power adjustment amount calculated according to the voltage deviation, combined with the voltage-reactive power characteristic curve, and the dispatching reactive power distribution instruction is generated through the reactive power adjustment amount; The main station voltage distribution instruction provides a reference for the voltage setting of the subsystems including solar thermal voltage setting, energy storage voltage setting, photovoltaic fast response voltage setting, diesel generator voltage setting, and SVG voltage setting according to the characteristics of different subsystems. The dispatching reactive power distribution instruction distributes reactive power instructions including energy storage reactive power instruction, photovoltaic reactive power instruction, diesel generator reactive power instruction, and SVG reactive power instruction according to the characteristics of each subsystem and its role in voltage regulation, in combination with boundary conditions including energy storage operation boundary conditions, photovoltaic operation boundary conditions, diesel generator operation boundary conditions, and SVG operation boundary conditions. The solar thermal system calculates the solar thermal system voltage deviation value through the solar thermal voltage setting and the outlet voltage of the solar thermal unit, and calculates the solar thermal reactive power instruction through the solar thermal system voltage deviation value. The energy storage system sets the energy storage primary voltage regulation instruction through the energy storage voltage setting, and the energy storage primary voltage regulation instruction and the energy storage reactive power instruction are summarized to generate the actual energy storage reactive power instruction. The photovoltaic system sets the photovoltaic fast response primary voltage regulation instruction through the photovoltaic fast response voltage setting, and the photovoltaic fast response primary voltage regulation instruction and the photovoltaic reactive power instruction are summarized to generate the actual photovoltaic reactive power instruction. The diesel generator system sets the diesel generator system primary voltage regulation instruction through the diesel generator voltage setting, and the diesel generator system primary voltage regulation instruction and the diesel generator reactive power instruction are summarized to generate the actual diesel generator reactive power instruction. The SVG control system sets the SVG system primary voltage regulation instruction through the SVG voltage setting, and the SVG system primary voltage regulation instruction and the SVG reactive power instruction are summarized to generate the actual SVG reactive power instruction.

[0012] Further, in step S2, when the operation mode is the solar energy storage diesel mode, the main station voltage distribution instruction and the dispatching reactive power distribution instruction are calculated, and the voltage is distributed to each subsystem for regulation to form a real-time secondary voltage regulation control strategy, specifically: Obtain the bus voltage set value and the actual bus voltage, and calculate the main station voltage distribution instruction and the dispatching reactive power distribution instruction respectively. Among them, the main station voltage distribution instruction is generated based on the deviation value between the bus voltage set value and the actual bus voltage, in combination with the voltage regulation characteristics and control strategy of the system. The main station voltage distribution instruction = Kp × voltage deviation + Ki × ∫ voltage deviation dt, where Kp is the proportional coefficient and Ki is the integral coefficient. The dispatching reactive power distribution instruction is the reactive power adjustment amount calculated based on the voltage deviation in combination with the voltage-reactive power characteristic curve, and the dispatching reactive power distribution instruction is generated through the reactive power adjustment amount. The main station voltage distribution instruction provides a reference for the voltage setting of the subsystems including energy storage voltage setting, photovoltaic fast response voltage setting, diesel generator voltage setting, and SVG voltage setting according to the characteristics of different subsystems; The dispatching reactive power distribution instruction distributes reactive power instructions including photovoltaic reactive power instructions, diesel generator reactive power instructions, and SVG reactive power instructions according to the characteristics of each subsystem and its role in voltage regulation, in combination with boundary conditions including photovoltaic operation boundary conditions, diesel generator operation boundary conditions, and SVG operation boundary conditions; The energy storage system calculates the voltage deviation value of the energy storage system through the energy storage voltage setting and the actual voltage of the energy storage system, and calculates the energy storage reactive power instruction through the voltage deviation value of the energy storage system; The photovoltaic system sets the photovoltaic fast response primary voltage regulation instruction through the photovoltaic fast response voltage setting, and the photovoltaic fast response primary voltage regulation instruction and the photovoltaic reactive power instruction are aggregated to generate the actual photovoltaic reactive power instruction; The diesel generator system sets the primary voltage regulation instruction of the diesel generator system through the diesel generator voltage setting, and the primary voltage regulation instruction of the diesel generator system and the diesel generator reactive power instruction are aggregated to generate the actual diesel generator reactive power instruction; The SVG control system sets the primary voltage regulation instruction of the SVG system through the SVG voltage setting, and the primary voltage regulation instruction of the SVG system and the SVG reactive power instruction are aggregated to generate the actual SVG reactive power instruction.

[0013] Further, in step S3, according to the secondary voltage regulation control strategy, comprehensively judge the parameters including frequency, tie-line power flow, voltage, and tie-line connection / disconnection at each measurement point, obtain the operation modes of each subsystem, and generate the dispatching AGC / AVC instruction according to the bus voltage set value and the actual bus voltage. Specifically: At the measurement point of voltage, collect parameters including frequency, tie-line power flow, voltage, and tie-line connection / disconnection through sensors; Use data analysis algorithms including a voltage harmonic analysis algorithm based on discrete Fourier transform and a power flow calculation algorithm based on power flow calculation equations to process the collected parameters to determine the reactive power distribution and tie-line power flow state of the power grid, and clarify the flow direction and magnitude of reactive power in the power grid; Based on the collected and processed parameters, in combination with the pre-established operation model of the subsystem, judge the operation modes of each subsystem, where the operation model of the subsystem takes into account the physical characteristics and operation parameters of different types of subsystems including solar thermal, photovoltaic, energy storage, and diesel generator, and is dynamically updated according to actual operation data; According to the deviation between the set value of the bus voltage and the actual bus voltage, a preliminary voltage regulation command is generated using a proportional-integral (PI) control algorithm. The proportional coefficient Kp and the integral coefficient Ki are determined based on the electrical characteristics of the power grid and the voltage regulation response characteristics of each subsystem, such that the voltage regulation amount ΔU = Kp×(U_set - U_real) + Ki×∫(U_set - U_real)dt, where U_set is the set voltage value and U_real is the actual voltage value; According to the voltage deviation and the requirements of reactive power balance in the power grid, a reactive power optimization algorithm based on the optimal power flow algorithm is used to generate a dispatching AGC / AVC command.

[0014] Further, in step S4, after the dispatching AGC / AVC command is adjusted by the adjustment coefficients of each subsystem, it is sent to each subsystem for voltage and reactive power regulation to maintain voltage stability. Specifically: Each subsystem pre-sets the adjustment coefficient, which is determined according to the type, equipment performance, historical operation data, and current operation status of each subsystem. Among them, the adjustment coefficient of the solar thermal system considers factors including the thermal efficiency of the energy storage system, the adjustment range and response speed of the steam turbine; the adjustment coefficient of the photovoltaic system considers factors including the conversion efficiency of the photovoltaic panel, the adjustment ability of the inverter, and the light intensity; the adjustment coefficient of the energy storage system considers factors including the charge and discharge characteristics of the battery, the state of charge (SOC), and the charge and discharge power limit; the adjustment coefficient of the diesel generator system considers factors including the start-up time, output power range, and fuel efficiency of the diesel generator set; the adjustment coefficient of the SVG control system considers factors including the capacity, response speed, adjustment range, and compensation ability of the SVG; After receiving the adjusted command, the subsystem performs voltage and reactive power regulation operations according to the command. For the solar thermal system, by adjusting the steam inlet volume of the steam turbine or the heat release of the energy storage system, the excitation current of the generator is changed, and then the reactive power output is adjusted to achieve voltage regulation; the photovoltaic system adjusts the voltage and current operating points of the inverter to change its reactive power output to achieve voltage regulation; the energy storage system relies on controlling the charge and discharge power of the converter to change its own reactive power output, thereby affecting the voltage; the diesel generator system adjusts the throttle opening and speed of the diesel generator set, adjusts the excitation current of the generator, and controls the reactive power output to achieve voltage regulation; the SVG control system adjusts the internal power electronic components to change the output reactive power, and quickly outputs or absorbs reactive power according to the requirements of the power grid, thereby regulating the voltage; And during the voltage and reactive power regulation process of each of the said subsystems, the regulation status information is fed back to the dispatching system in real time. The dispatching system dynamically optimizes the said adjustment coefficients and instructions according to the feedback information to achieve precise voltage and reactive power control.

[0015] Furthermore, the real-time secondary voltage regulation control method for the high-altitude isolated network energy station further includes setting bus voltage control constraint conditions including bus and generator terminal voltage constraints, on-load tap-changer tap position constraints, and compensation capacitor bank switching capacity constraints, specifically as follows: Monitor the voltage through voltage transformers installed on the bus and at the generator terminals. When the bus or generator terminal voltage exceeds the set range, adjust the reactive power by means including the generator excitation system to control the voltage within the allowable range; Use the on-load tap-changer tap position sensor to monitor the tap position. According to the bus voltage situation and the tap position range, and on the premise of meeting the operation restrictions, adjust the tap position in a timely manner to assist in voltage regulation; Monitor the switching state and capacity of the compensation capacitor bank, and switch the capacitor bank within the allowable range according to the voltage situation and the capacitor bank switching capacity constraints to provide reactive power support for voltage regulation and ensure the stability of the bus voltage.

[0016] A real-time secondary voltage regulation control system for a high-altitude isolated network energy station for implementing the real-time secondary voltage regulation control method for a high-altitude isolated network energy station as described above includes: A bus actual voltage acquisition module, which is used to collect the voltage values of several measurement points on the bus according to the electrical quantity acquisition device, and optimize the voltage values of the measurement points according to the power grid topology identification situation to obtain the optimized bus voltage value as the bus actual voltage; A voltage regulation control strategy acquisition module, which is used to preset the bus voltage set value, and calculate the master station voltage distribution instruction and the dispatching reactive power distribution instruction according to the bus voltage set value and the bus actual voltage according to different operation modes, and distribute the voltage to each subsystem for regulation to form a real-time secondary voltage regulation control strategy; A subsystem dispatching instruction generation module, which is used to comprehensively judge the parameters including frequency, tie-line power flow, voltage, and tie-line connection / disconnection of each of the said measurement points according to the secondary voltage regulation control strategy, obtain the operation modes of each of the said subsystems, and generate dispatching AGC / AVC instructions according to the bus voltage set value and the bus actual voltage; A subsystem power regulation execution module, which is used to send the dispatching AGC / AVC instructions to each of the said subsystems for voltage and reactive power regulation after being adjusted by the adjustment coefficients of each of the said subsystems to maintain voltage stability.

[0017] A computer device includes a memory and one or more processors. Computer code is stored in the memory. When the computer code is executed by the one or more processors, the one or more processors are caused to execute the method as described above.

[0018] A computer-readable storage medium stores computer code. When the computer code is executed, the method as described above is executed.

[0019] Compared with the prior art, the present invention has at least one of the following beneficial effects: (1) Improve voltage stability By collecting voltage values at multiple measurement points and making selections based on the power grid topology, the optimal bus voltage value is obtained as the actual bus voltage, enabling a more accurate grasp of the system voltage state and providing a reliable basis for subsequent voltage regulation control. Especially under different operating conditions (such as when the solar thermal power unit is operating or not operating), a reasonable voltage selection order helps to select the most representative and reliable voltage measurement value, avoiding misleading the overall voltage regulation decision due to a single measurement point failure or local voltage anomaly, and ensuring that the bus voltage can be effectively monitored and regulated in various situations.

[0020] Voltage regulation is carried out using the master station voltage distribution instruction and the dispatching reactive power distribution instruction. By combining the voltage setting of different subsystems and the generation and distribution of reactive power instructions, refined control of the system voltage can be achieved. Using the proportional-integral (PI) control algorithm based on the voltage deviation, the voltage can be dynamically adjusted according to the system characteristics, effectively suppressing voltage fluctuations, stabilizing the bus voltage near the set value, avoiding damage to electrical equipment caused by large voltage fluctuations, extending the service life of the equipment, and ensuring the stable operation of the power system of the plateau isolated network energy station.

[0021] (2) Enhance system adaptability and reliability Considering different operating modes (such as the solar thermal + solar energy storage and diesel combined mode, the solar energy storage and diesel combined mode), the master station voltage distribution instruction and the dispatching reactive power distribution instruction are generated specifically, which can better meet the voltage regulation requirements under various power source combinations and system configurations. Different subsystems refine the reactive power instruction to each subsystem (solar thermal, energy storage, photovoltaic, diesel generation, SVG, etc.) according to their own boundary conditions and voltage deviation information, realizing differential and refined regulation of the system, improving the system's adaptability to different operating conditions, and ensuring efficient voltage control in various operating modes.

[0022] Based on the comprehensive analysis of the subsystem operation model, physical characteristics, and operation parameters, and dynamically updating the model according to the actual operation data, it is possible to adjust the control strategy according to the real-time state of the system. When a fault or performance change occurs in a certain subsystem of the system, the operation mode can be adjusted in a timely manner, making the system have stronger adaptability and fault tolerance, and improving the reliability of the entire energy station.

[0023] (3)Achieve precise power and reactive power regulation Using sensors to collect parameters such as frequency, tie-line power flow, voltage, and tie-line connection and disconnection, through advanced data analysis algorithms (such as voltage harmonic analysis algorithm of discrete Fourier transform, power flow calculation algorithm), the reactive power distribution and tie-line power flow state of the power grid can be deeply analyzed to ensure an accurate grasp of the system state. According to the voltage deviation and the requirements of power grid reactive power balance, the reactive power optimization algorithm using the optimal power flow algorithm generates dispatching AGC / AVC commands, realizing the optimal distribution of reactive power, which can not only meet the voltage regulation requirements but also take into account the reactive power balance of the power grid, reduce reactive power losses, and improve the power quality and efficiency of the system.

[0024] Each subsystem adjusts voltage and reactive power according to the adjustment coefficient. The adjustment coefficient comprehensively considers various factors of each subsystem (such as heat storage and steam turbine characteristics of the solar thermal system, light intensity and inverter characteristics of the photovoltaic system, battery state of the energy storage system, unit performance of the diesel generator system, performance of the SVG control system), making the adjustment instructions more in line with the actual capabilities of the subsystems and the overall requirements of the system. Each subsystem can precisely adjust the reactive power output through its own unique adjustment methods (such as steam turbine steam intake and heat storage release of the solar thermal system, inverter adjustment of the photovoltaic system, converter control of the energy storage system, throttle and speed adjustment of the diesel generator system, power electronic component adjustment of the SVG control system), realizing precise voltage regulation and meeting the precise control requirements of the system for voltage and reactive power.

[0025] (4)Meet the constraint conditions to ensure the safe and stable operation of the system Set bus voltage control constraint conditions such as bus and generator terminal voltage constraints, on-load tap-changer tap position constraints, and compensation capacitor bank switching capacity constraints to ensure the system operates within a safe range. By monitoring voltage, tap position, and capacitor bank status, and timely adjusting reactive power, tap position, and capacitor bank switching, equipment damage and system failures caused by situations such as too high or too low voltage, improper operation of transformer tap changers, over-switching or under-switching of capacitor banks are avoided, ensuring the safe and stable operation of the system in the special environment of a high-altitude isolated power grid. At the same time, on the basis of meeting the constraint conditions, voltage regulation is achieved, ensuring the continuity and reliability of the power supply of the entire energy station and avoiding adverse effects on other parts of the system caused by voltage control operations.

[0026] (5) Dynamic Optimization and Real-time Feedback Mechanism During the voltage and reactive power regulation process of each subsystem, the regulation status information is fed back to the dispatching system in real time. The dispatching system dynamically optimizes the adjustment coefficients and commands based on the feedback information, forming a closed-loop control loop. This dynamic optimization mechanism can continuously adjust the control strategy according to the actual response of the system, continuously optimize the control performance of the system, improve the accuracy and response speed of voltage control, ensure that the system always maintains an efficient and stable operating state during long-term operation, adapt to the dynamic changes of the system and various uncertain factors, and achieve precise, dynamic, and continuous effective control of the system voltage and reactive power. Brief Description of the Drawings

[0027] Figure 1 It is the overall flowchart of the real-time secondary voltage regulation control method for the high-altitude isolated network energy station of the present invention; Figure 2 It is the block diagram of the real-time secondary voltage regulation strategy for the solar thermal + solar energy storage with diesel generator mode of the present invention; Figure 3 It is the block diagram of the real-time secondary voltage regulation strategy for the solar energy storage with diesel generator mode of the present invention; Figure 4 It is the overall structure diagram of the real-time secondary voltage regulation control system for the high-altitude isolated network energy station of the present invention. Specific Embodiments

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0029] Those skilled in the art of this technology can understand that unless specifically stated otherwise, the singular forms "a", "an", "the", and "said" used herein may also include the plural forms. It should be further understood that the term "comprising" used in the specification of the present invention means the presence of the described features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or their groups.

[0030] First Embodiment As Figure 1 shown, this embodiment provides a real-time secondary voltage regulation control method for a high-altitude isolated network energy station, including the following steps: S1: Collect the voltage values of several measurement points on the bus according to the electrical quantity acquisition device, optimize the voltage values of the measurement points based on the power grid topology identification situation, and obtain the optimized bus voltage value as the actual bus voltage.

[0031] In this embodiment, step S1 is specifically as follows: Collect the PT signals on the bus line according to the electrical quantity acquisition device, including the voltage values of the measurement points such as the voltage collected by the energy collection station bus, the voltage collected by the solar thermal power plant bus, and the voltage collected by the photovoltaic power plant bus; When the voltage values are all normal, take the higher voltage value among the voltage collected by the energy collection station bus, the voltage collected by the solar thermal power plant bus, and the voltage collected by the photovoltaic power plant bus as the optimized bus voltage value; When a fault occurs in the voltage value of any one of the measurement points, obtain the optimized bus voltage value in the following order: When the solar thermal unit is running, obtain the optimized bus voltage value in the order of the voltage collected by the energy collection station bus, the voltage collected by the solar thermal power plant bus, and the voltage collected by the photovoltaic power plant bus; when the solar thermal unit is not running, obtain the optimized bus voltage value in the order of the voltage collected by the energy collection station bus, the voltage collected by the photovoltaic power plant bus, and the voltage collected by the solar thermal power plant bus.

[0032] The following is a further explanation of the above technical solution: I. Electrical quantity acquisition and measurement points This part mainly involves using the electrical quantity acquisition device to collect the voltage signals on the bus line. By installing voltage transformers (PTs) at key positions such as the energy collection station bus, the solar thermal power plant bus, and the photovoltaic power plant bus, the voltage values of these measurement points can be obtained. These measurement points are crucial for the voltage monitoring and regulation of the entire system because they represent the voltage states of different parts of the system respectively: Voltage collected by the energy collection station bus: As the core hub for energy collection and distribution, its voltage reflects the comprehensive voltage level of the entire system, integrating the interactions from various power sources (solar thermal, photovoltaic, etc.) and loads, and is an important indicator for evaluating the overall voltage condition of the system.

[0033] Voltage collected by the solar thermal power plant bus: Reflects the voltage output of the solar thermal power plant. The solar thermal power plant usually has relatively stable power generation characteristics, and its voltage measurement value can provide information on the operating state of the solar thermal power generation part. Especially when the solar thermal unit is running, it is of great significance for judging whether the solar thermal power generation system is normal and its contribution to the system voltage.

[0034] Bus voltage acquisition of photovoltaic power station: Since photovoltaic power stations are greatly affected by environmental factors such as light intensity and weather, their output voltage fluctuates significantly. The voltage at this measurement point can reflect the instantaneous power generation status of the photovoltaic power station, which helps to understand the performance of the photovoltaic power source and its impact on the system voltage.

[0035] II. Determination of the preferred value of bus voltage (normal situation) When the voltage values of all measurement points are normal, the higher voltage value among the three is taken as the preferred value of the bus voltage. The logic behind this selection is that under normal circumstances, a higher voltage value may be more conducive to power transmission and distribution, and to a certain extent, it indicates that the system is in a better power supply state, providing a better reference for subsequent power dispatching and control. For example, during normal operation, if the bus voltage acquired by the energy collection station is 35.2 kV, the bus voltage acquired by the solar thermal power station is 35.0 kV, and the bus voltage acquired by the photovoltaic power station is 34.8 kV, then the preferred value of the bus voltage will be 35.2 kV. This can ensure that when the power is sufficient, the system can operate at a relatively high voltage, improving the operating efficiency and power quality of the system.

[0036] III. Determination of the preferred value of bus voltage (fault situation) When a voltage fault occurs, different preferred orders are adopted according to the operating state of the solar thermal unit: When the solar thermal unit is operating: Priority is given to the bus voltage acquired by the energy collection station because it is the core hub of the system, and the stability of its voltage has the greatest impact on the entire system. Even if a fault occurs at a certain measurement point, the voltage information of the energy collection station still plays a key guiding role in the overall stable operation and fault troubleshooting of the system.

[0037] Secondly is the bus voltage acquired by the solar thermal power station. The solar thermal unit has relatively stable power generation characteristics. When the solar thermal unit is operating, its bus voltage can reflect the status of the solar thermal power station itself, which is of great value for evaluating the support and regulation ability of the solar thermal power station to the system voltage.

[0038] Finally is the bus voltage acquired by the photovoltaic power station. Because the photovoltaic power station is greatly affected by the environment, the reliability of its bus voltage during a fault is relatively low and may not accurately reflect the overall voltage status and recovery ability of the system. Therefore, it is the last choice.

[0039] When the solar thermal unit is not operating: Similarly, priority is given to the bus voltage acquired by the energy collection station because its status as the core hub remains unchanged. Whether the solar thermal unit is operating or not, it undertakes the important functions of power collection and distribution.

[0040] Secondly, the voltage of the busbar of the PV power station is collected. At this time, the PV power station may be one of the main power sources, and its voltage information can reflect the status of the current main power generation source, which is important for understanding the power supply side of the system.

[0041] Finally, the voltage of the busbar of the CSP power station is collected. Since the CSP units are not operating and the CSP power station does not output power at this time, its busbar voltage is mainly affected by factors such as the status of electrical equipment in the station, and its reference value for the current voltage condition of the system and fault recovery is relatively low.

[0042] This method of determining the optimal value of the busbar voltage helps to reasonably select the measured value that can best reflect the actual voltage condition of the system according to the actual situation of the system and the characteristics of different measurement points under different working conditions, providing a more accurate and reliable basis for subsequent voltage regulation, system control, and fault handling, and ensuring that the system can maintain relatively stable and reliable voltage control under normal operation and fault conditions.

[0043] S2: Preset the busbar voltage set value, calculate the master station voltage distribution command and the dispatching reactive power distribution command according to the busbar voltage set value and the actual busbar voltage according to different operating modes, and distribute the voltage to each subsystem for adjustment to form a real-time secondary voltage regulation control strategy.

[0044] (1) As Figure 2 shown in the CSP+PV+BESS+Diesel mode Obtain the busbar voltage set value and the actual busbar voltage, and calculate the master station voltage distribution command and the dispatching reactive power distribution command respectively. Among them, the master station voltage distribution command is generated based on the deviation value between the busbar voltage set value and the actual busbar voltage, combined with the voltage regulation characteristics and control strategy of the system. The master station voltage distribution command = Kp×voltage deviation + Ki×∫voltage deviation dt, where Kp is the proportional coefficient and Ki is the integral coefficient. The dispatching reactive power distribution command is the reactive power adjustment amount calculated based on the voltage deviation in combination with the voltage-reactive power characteristic curve, and the dispatching reactive power distribution command is generated through the reactive power adjustment amount; The master station voltage distribution command provides a reference for the voltage setting of the subsystems including CSP voltage setting, energy storage voltage setting, PV fast power voltage setting, diesel generator voltage setting, and SVG voltage setting according to the characteristics of different subsystems; The dispatching reactive power distribution command is distributed into reactive power commands including energy storage reactive power command, PV reactive power command, diesel generator reactive power command, and SVG reactive power command according to the characteristics of each subsystem and its role in voltage regulation, in combination with boundary conditions including energy storage operation boundary conditions, PV operation boundary conditions, diesel generator operation boundary conditions, and SVG operation boundary conditions; The solar thermal system calculates the voltage deviation value of the solar thermal system based on the solar thermal voltage setting and the outlet voltage of the solar thermal unit, and calculates the solar thermal reactive power command based on the voltage deviation value of the solar thermal system; The energy storage system sets the primary voltage regulation command of the energy storage through the energy storage voltage setting, and the primary voltage regulation command of the energy storage and the reactive power command of the energy storage are summarized to generate the actual reactive power command of the energy storage; The photovoltaic system sets the primary voltage regulation command of the photovoltaic fast reactive power through the photovoltaic fast reactive power voltage setting, and the primary voltage regulation command of the photovoltaic fast reactive power and the reactive power command of the photovoltaic are summarized to generate the actual reactive power command of the photovoltaic; The diesel generator system sets the primary voltage regulation command of the diesel generator system through the diesel generator voltage setting, and the primary voltage regulation command of the diesel generator system and the reactive power command of the diesel generator are summarized to generate the actual reactive power command of the diesel generator; The SVG control system sets the primary voltage regulation command of the SVG system through the SVG voltage setting, and the primary voltage regulation command of the SVG system and the reactive power command of the SVG are summarized to generate the actual reactive power command of the SVG.

[0045] The following is a detailed explanation of the above technical solutions: I. Basis for Data Acquisition and Command Generation Determination of the bus voltage set value: The bus voltage set value is the target value for the voltage regulation of the entire system. It is not set randomly but is comprehensively considered based on multiple factors. First of all, according to the standard specifications of power grid operation, it is necessary to ensure that the set value meets the requirements of the safe and stable operation of the power grid. Secondly, it is necessary to combine the rated voltage and the normal working voltage range of various electrical equipment in the high-altitude isolated network energy station to ensure that these equipment can operate efficiently in a stable voltage environment, avoiding damage to the equipment caused by too high or too low voltage, and affecting production and operation efficiency. In addition, it is also necessary to consider the overall power supply capacity and power transmission characteristics of the energy station, such as line losses, transformer turns ratios, etc., so that the set value is feasible and reasonable in the actual power supply process. This set value is an important benchmark for system operation and provides a clear target direction for subsequent voltage regulation.

[0046] Collection of the actual bus voltage: In order to obtain the actual bus voltage, special electrical quantity collection devices need to be installed on the bus line. These devices can measure the bus voltage in real time and accurately, and transmit the measurement data to the control system. The accuracy and reliability of the collection devices are crucial. They need to be able to work stably under various complex working conditions, not affected by factors such as electromagnetic interference and temperature changes, to ensure that the collected voltage data truly reflects the actual voltage state of the bus. By continuously collecting the actual bus voltage, the control system can grasp the voltage dynamics of the system in real time, providing data support for timely detection of voltage abnormalities and effective voltage regulation.

[0047] Calculation and Significance of Voltage Deviation: Compare the actually measured bus voltage collected with the preset bus voltage setpoint, and calculate the difference between the two, which is the voltage deviation. The voltage deviation is a key indicator in the entire voltage regulation process, directly reflecting the deviation degree between the current bus voltage and the target voltage. A positive voltage deviation indicates that the actual bus voltage is higher than the setpoint, while a negative voltage deviation indicates that the actual voltage is lower than the setpoint. The magnitude and positive / negative direction of this deviation value provide an important basis for generating the master station voltage distribution instruction and the dispatching reactive power distribution instruction. The control system will take corresponding adjustment measures according to the specific situation of the voltage deviation to gradually make the bus voltage approach the setpoint and achieve stable voltage control.

[0048] II. Functions and Impacts of the Master Station Voltage Distribution Instruction Generation Principle of the Master Station Voltage Distribution Instruction: Based on the calculated voltage deviation, combined with the voltage regulation characteristics and control strategies of the system to generate the master station voltage distribution instruction. The voltage regulation characteristics of the system include the response speed, regulation range, regulation accuracy, etc. of each subsystem (such as solar thermal, energy storage, photovoltaic, diesel generator, SVG, etc.) for voltage regulation, as well as the voltage transmission characteristics and reactive power distribution characteristics of the entire power grid. The control strategy is a set of rules and methods formulated according to the operation objectives and constraints of the system, used to guide the generation of the master station voltage distribution instruction. For example, in some cases, it may be necessary to give priority to fast-response subsystems for voltage regulation, while in other cases, it may be necessary to comprehensively consider the coordinated regulation of multiple subsystems to achieve the optimal voltage control effect. The generation process of the master station voltage distribution instruction is a complex process that comprehensively considers various factors, aiming to achieve fast and stable regulation of the bus voltage by reasonably allocating voltage regulation tasks.

[0049] Guiding role for the voltage setting of each subsystem: The generated master station voltage distribution instruction will provide specific references for the voltage setting of different subsystems according to their characteristics. For the solar thermal system, the master station voltage distribution instruction will affect the solar thermal voltage setting value. As an important part of the energy station, the voltage setting of the solar thermal system needs to consider the operating characteristics of the solar thermal unit, such as the heat storage capacity of the solar thermal unit and the operating parameters of the steam turbine. The master station voltage distribution instruction will provide a reasonable target value for the solar thermal voltage setting based on the overall voltage demand of the system and the current state of the solar thermal system, guiding the solar thermal system to play its due role in the voltage regulation process. For the energy storage system, the master station voltage distribution instruction will affect the energy storage voltage setting. The energy storage system has the ability of rapid charge and discharge, and its voltage setting needs to consider factors such as the state of charge of the energy storage battery and the charge and discharge power limit to ensure that the energy storage system can meet the reactive power demand of the system while participating in voltage regulation and ensure the safety and life of the battery. The photovoltaic fast power voltage setting of the photovoltaic system will also be affected by the master station voltage distribution instruction. The output power of the photovoltaic system is greatly affected by factors such as light intensity, and its voltage setting needs to consider the characteristics of photovoltaic modules and the regulation ability of inverters so that the photovoltaic system can effectively participate in voltage regulation under different light conditions. The diesel generator voltage setting of the diesel generator system is also based on the master station voltage distribution instruction. As a backup power supply or the main power supply under specific working conditions, the voltage setting of the diesel generator system needs to consider factors such as the start-up time, output power range, and fuel efficiency of the diesel generator set to ensure the stability and reliability of the diesel generator system in the voltage regulation process. The SVG voltage setting of the SVG control system will also be adjusted according to the master station voltage distribution instruction. As a fast reactive power compensation device, the voltage setting of the SVG needs to consider characteristics such as the capacity, response speed, regulation range, and compensation ability of the SVG so that the SVG can quickly and accurately respond to voltage changes and achieve effective regulation of the bus voltage. Through the guidance of the master station voltage distribution instruction for the voltage setting of each subsystem, each subsystem can work together to jointly achieve the stable control of the bus voltage.

[0050] III. Generation and Distribution Details of Dispatching Reactive Power Distribution Instructions Generation process of the dispatching reactive power allocation instruction: The dispatching reactive power allocation instruction is generated based on the voltage deviation, in combination with the inherent relationship between voltage and reactive power in the system. This inherent relationship can be reflected by the voltage-reactive power characteristic curve of the system, which shows the magnitude and variation trend of the reactive power required by the system at different voltage levels. When there is a voltage deviation at the bus, according to the voltage-reactive power characteristic curve, it is possible to determine the amount of reactive power that needs to be increased or decreased and the adjustment direction of reactive power in order to adjust the voltage to the set value. For example, if the bus voltage is lower than the set value, it can be known from the characteristic curve that reactive power needs to be increased to raise the voltage, and then a corresponding dispatching reactive power allocation instruction to increase reactive power will be generated; conversely, if the bus voltage is higher than the set value, an instruction to decrease reactive power will be generated. This process requires an accurate understanding and modeling of the voltage-reactive power characteristics of the system to ensure that the generated dispatching reactive power allocation instruction can effectively guide the adjustment of reactive power and achieve the stability of the bus voltage.

[0051] Allocation of the dispatching reactive power allocation instruction in each subsystem: Solar thermal system: The solar thermal system first calculates the voltage deviation of the solar thermal system by comparing the set value of the solar thermal voltage with the actual voltage at the outlet of the solar thermal unit. This calculation process involves precise measurement and comparison of the voltage parameters of the solar thermal system to accurately reflect the difference between the current voltage state and the target state of the solar thermal system. Then, according to the characteristics and control requirements of the solar thermal system, this voltage deviation is converted into a solar thermal reactive power instruction. The characteristics of the solar thermal system include the excitation system characteristics of the solar thermal unit, the operating characteristics of the steam turbine, etc. These characteristics determine the response mode of the solar thermal system to voltage deviation and the reactive power adjustment ability. The generated solar thermal reactive power instruction will be sent to the control equipment of the solar thermal unit, such as the excitation regulator, etc. These devices will adjust the operating parameters of the solar thermal unit according to the instruction, thereby changing the reactive power output by the solar thermal unit. For example, when the solar thermal reactive power instruction requires an increase in reactive power, the excitation regulator will increase the excitation current, causing the solar thermal unit to output more reactive power and participate in raising the bus voltage; conversely, when the instruction requires a decrease in reactive power, the excitation regulator will correspondingly decrease the excitation current to reduce the reactive power output and assist in stabilizing the bus voltage.

[0052] Energy storage system: The energy storage system sets the primary voltage regulation command of the energy storage according to the set value of the energy storage voltage. The set value of the energy storage voltage is determined based on the main station voltage distribution command and the operating status of the energy storage system itself, which provides a target value for the voltage regulation of the energy storage system. The primary voltage regulation command of the energy storage is added to the reactive power command of the energy storage to obtain a comprehensive command signal. In this process, the boundary conditions of energy storage operation need to be considered simultaneously. These boundary conditions include the charge and discharge power limit of the battery, the state of charge (SOC) of the battery, the temperature limit of the battery, etc. For example, if the state of charge of the battery is low, it may limit the ability of the energy storage system to output reactive power. In this case, this factor needs to be considered when generating the actual reactive power command of the energy storage to avoid over-discharging the battery and causing damage. At the same time, the charge and discharge power limit will also affect the regulation speed and amplitude of the reactive power of the energy storage system. The actual reactive power command of the energy storage generated according to these comprehensive factors will be sent to the control equipment such as the converter of the energy storage system, and the converter will adjust the output reactive power according to the command to achieve the regulation of the bus voltage. For example, when the bus voltage is low and the energy storage system has sufficient regulation ability, the actual reactive power command of the energy storage will require the converter to output reactive power to increase the bus voltage; when the bus voltage is high, the command will require the converter to absorb reactive power to reduce the bus voltage.

[0053] Photovoltaic system: The photovoltaic system sets the primary voltage regulation command of the photovoltaic fast power through the set value of the photovoltaic fast power voltage. The set value of the photovoltaic fast power voltage is determined according to the main station voltage distribution command and the real-time operating status of the photovoltaic system, aiming to enable the photovoltaic system to quickly respond to the change of the bus voltage. The primary voltage regulation command of the photovoltaic fast power is added to the reactive power command of the photovoltaic, and the actual reactive power command of the photovoltaic is generated in combination with the boundary conditions of photovoltaic operation. The boundary conditions of photovoltaic operation include factors such as the maximum power point tracking (MPPT) limit of photovoltaic modules, the capacity limit of inverters, and the light intensity. For example, in the case of weak light intensity, the output power of photovoltaic modules is low, which may affect the ability of the photovoltaic system to output reactive power. In this case, this limit needs to be considered when generating the actual reactive power command of the photovoltaic to ensure that the photovoltaic system operates within a safe and efficient range. According to the actual reactive power command of the photovoltaic, the inverter of the photovoltaic system will adjust the operating point and change the output reactive power to participate in the regulation of the bus voltage. When the bus voltage needs to be increased, the inverter may adjust the operating point to increase the reactive power output; when the bus voltage needs to be decreased, the inverter will correspondingly reduce the reactive power output or absorb reactive power.

[0054] Diesel generator system: The diesel generator system sets the primary voltage regulation command of the diesel generator system through the diesel generator voltage set value. The determination of the diesel generator voltage set value needs to consider the operating characteristics of the diesel generator set and the voltage regulation requirements of the system, which provides a reference target for the voltage regulation of the diesel generator system. The primary voltage regulation command of the diesel generator system is added to the diesel generator reactive power command, and at the same time, the operating boundary conditions of the diesel generator need to be considered. These boundary conditions include the start-up time of the diesel generator set, the output power range, the fuel efficiency, the emission requirements, etc. For example, the start-up time of the diesel generator set is relatively long. When there is an emergency voltage fluctuation in the system, it may not be able to be put into operation immediately for voltage regulation. Therefore, this factor needs to be considered when formulating the actual reactive power command of the diesel generator, and the participation timing of the diesel generator system should be reasonably arranged. According to the actual reactive power command of the diesel generator, the diesel generator system adjusts the excitation current of the generator by adjusting the throttle opening, speed, etc., so as to control the reactive power output. When more reactive power is needed, the diesel generator system increases the throttle opening, raises the speed, increases the excitation current, and outputs more reactive power; when less reactive power is needed, the opposite operation is taken to achieve the regulation of the bus voltage.

[0055] SVG control system: The SVG control system sets the primary voltage regulation command of the SVG system through the SVG voltage set value. The SVG voltage set value is determined according to the main station voltage distribution command and the performance parameters of the SVG system, aiming to give full play to the fast and flexible reactive power regulation ability of the SVG. The primary voltage regulation command of the SVG system is added to the SVG reactive power command, and at the same time, the operating boundary conditions of the SVG need to be considered. These boundary conditions include the capacity of the SVG, the response speed, the regulation range, the compensation ability, and the heat dissipation conditions, etc. For example, the capacity of the SVG determines the maximum reactive power that it can output or absorb. When generating the actual reactive power command of the SVG, it is necessary to ensure that the command value is within the capacity range of the SVG to avoid equipment overload. According to the actual reactive power command of the SVG, the SVG quickly outputs or absorbs reactive power by adjusting internal power electronic components such as insulated gate bipolar transistors (IGBTs). When the bus voltage is low, the SVG can quickly output reactive power to boost the bus voltage; when the bus voltage is high, the SVG can quickly absorb reactive power to lower the bus voltage, thus achieving precise and fast regulation of the bus voltage.

[0056] (2) As Figure 3 shown is the photovoltaic-storage-diesel mode Obtain the set value of the bus voltage and the actual bus voltage, and calculate the master station voltage distribution instruction and the dispatching reactive power distribution instruction respectively. Among them, the master station voltage distribution instruction is generated based on the deviation value between the set value of the bus voltage and the actual bus voltage, combined with the voltage regulation characteristics and control strategy of the system. The master station voltage distribution instruction = Kp × voltage deviation + Ki × ∫ voltage deviation dt, where Kp is the proportionality coefficient and Ki is the integral coefficient. The dispatching reactive power distribution instruction is the reactive power adjustment amount calculated based on the voltage deviation, combined with the voltage-reactive power characteristic curve, and the dispatching reactive power distribution instruction is generated through the reactive power adjustment amount; The master station voltage distribution instruction provides a reference for the voltage setting of subsystems including energy storage voltage setting, photovoltaic fast reactive power voltage setting, diesel generator voltage setting, and SVG voltage setting according to the characteristics of different subsystems; The dispatching reactive power distribution instruction is allocated into reactive power instructions including photovoltaic reactive power instruction, diesel generator reactive power instruction, and SVG reactive power instruction according to the characteristics of each subsystem and its role in voltage regulation, combined with boundary conditions including photovoltaic operation boundary conditions, diesel generator operation boundary conditions, and SVG operation boundary conditions; The energy storage system calculates the voltage deviation value of the energy storage system through the energy storage voltage setting and the actual voltage of the energy storage system, and calculates the energy storage reactive power instruction through the voltage deviation value of the energy storage system; The photovoltaic system sets the photovoltaic fast reactive power primary voltage regulation instruction through the photovoltaic fast reactive power voltage setting, and the photovoltaic fast reactive power primary voltage regulation instruction and the photovoltaic reactive power instruction are summarized to generate the actual photovoltaic reactive power instruction; The diesel generator system sets the diesel generator system primary voltage regulation instruction through the diesel generator voltage setting, and the diesel generator system primary voltage regulation instruction and the diesel generator reactive power instruction are summarized to generate the actual diesel generator reactive power instruction; The SVG control system sets the SVG system primary voltage regulation instruction through the SVG voltage setting, and the SVG system primary voltage regulation instruction and the SVG reactive power instruction are summarized to generate the actual SVG reactive power instruction.

[0057] The above technical solutions are explained in detail as follows: I. Overall Process and Data Basis Data Acquisition and Processing: First of all, two key data need to be obtained, namely the set value of the bus voltage and the actual bus voltage. The set value of the bus voltage is a target value determined in advance according to factors such as system operation requirements, equipment characteristics, and grid specifications. It represents the ideal level at which the bus voltage is expected to be maintained. The actual bus voltage is obtained by real-time measurement of the electrical quantity acquisition device installed on the bus line, reflecting the current actual voltage state of the bus.

[0058] Compare the actual bus voltage with the set value of the bus voltage, calculate the difference between the two, and this difference is the voltage deviation. The voltage deviation is the core basis for the entire voltage regulation process, which intuitively reflects the degree and direction of the deviation of the bus voltage from the set value.

[0059] II. Generation and Function of Master Station Voltage Allocation Instructions Generation of master station voltage allocation instructions: Based on the calculated voltage deviation, combined with the voltage regulation characteristics and control strategies of the system, generate the master station voltage allocation instructions. The voltage regulation characteristics of the system cover various factors such as the response ability, regulation range of each subsystem (such as energy storage, photovoltaic, diesel generator, SVG, etc.) to voltage changes, and the voltage transmission characteristics of the entire power grid. The control strategy is a set of rules and methods formulated based on the operating objectives and various constraints of the system, used to guide the generation process of the master station voltage allocation instructions. For example, in some cases, it may be necessary to give priority to subsystems with fast response speed for voltage regulation, while in other cases, it may be necessary to comprehensively consider the coordinated regulation of multiple subsystems to achieve the optimal voltage control effect.

[0060] The role of the master station voltage allocation instructions is to provide reference and guidance for the voltage setting of each subsystem. Specifically, it will affect the energy storage voltage setting, photovoltaic fast power voltage setting, diesel generator voltage setting, and SVG voltage setting according to the characteristics of different subsystems. In this way, the overall requirements of the system for voltage regulation are decomposed into each subsystem, so that each subsystem can clearly define its own goals and directions in the voltage regulation process.

[0061] III. Generation and Allocation of Dispatching Reactive Power Allocation Instructions Generation of dispatching reactive power allocation instructions: Similarly, based on the voltage deviation, combined with the voltage-reactive power characteristic curve, calculate the reactive power adjustment amount. The voltage-reactive power characteristic curve describes the internal relationship between voltage and reactive power in the system. According to this curve, it is possible to determine the magnitude and direction of the reactive power that needs to be increased or decreased in order to adjust the voltage to the set value. Then, based on this reactive power adjustment amount, generate the dispatching reactive power allocation instructions.

[0062] Reactive power instructions allocated to each subsystem: Energy storage system: The energy storage system first calculates the voltage deviation of the energy storage system by comparing the set value of the energy storage voltage with the actual voltage of the energy storage system. This calculation process involves the accurate measurement and comparison of the voltage parameters of the energy storage system to accurately reflect the difference between the current voltage state and the target state of the energy storage system.

[0063] Then, according to the characteristics and control requirements of the energy storage system, this voltage deviation is converted into an energy storage reactive power command. The characteristics of the energy storage system include the charge and discharge characteristics of the battery, the state of charge (SOC), the charge and discharge power limits, etc. These characteristics determine the response mode of the energy storage system to voltage deviation and the reactive power regulation ability. The generated energy storage reactive power command will be sent to the control equipment of the energy storage system, such as converters, etc. These devices will adjust the operating parameters of the energy storage system according to the command, thereby changing the reactive power output by the energy storage system and participating in the regulation of the bus voltage. For example, when the bus voltage is low and the energy storage system has sufficient regulation ability, the energy storage reactive power command will require the converter to output reactive power to boost the bus voltage; when the bus voltage is high, the command will require the converter to absorb reactive power to lower the bus voltage.

[0064] Photovoltaic system: The photovoltaic system sets the photovoltaic fast-acting primary voltage regulation command through the photovoltaic fast-acting voltage setting value. The photovoltaic fast-acting voltage setting value is determined according to the main station voltage distribution command and the real-time operating state of the photovoltaic system, aiming to enable the photovoltaic system to quickly respond to the change of the bus voltage.

[0065] The photovoltaic fast-acting primary voltage regulation command and the photovoltaic reactive power command are summarized, and at the same time, considering the photovoltaic operation boundary conditions (such as the maximum power point tracking limit of photovoltaic modules, the capacity limit of inverters, light intensity, etc.), the actual photovoltaic reactive power command is generated. According to the actual photovoltaic reactive power command, the inverter of the photovoltaic system will adjust the operating point and change the output reactive power to participate in the regulation of the bus voltage. When the bus voltage needs to be boosted, the inverter may adjust the operating point to increase the reactive power output; when the bus voltage needs to be lowered, the inverter will correspondingly reduce the reactive power output or absorb reactive power.

[0066] Diesel generator system: The diesel generator system sets the diesel generator system primary voltage regulation command through the diesel generator voltage setting value. The determination of the diesel generator voltage setting value needs to consider the operating characteristics of the diesel generator set and the voltage regulation requirements of the system, which provides a reference target for the voltage regulation of the diesel generator system.

[0067] The diesel generator system primary voltage regulation command and the diesel generator reactive power command are summarized, and at the same time, considering the diesel generator operation boundary conditions (such as the start-up time of the diesel generator set, the output power range, fuel efficiency, emission requirements, etc.), the actual diesel generator reactive power command is generated. According to the actual diesel generator reactive power command, the diesel generator system will adjust the excitation current of the generator by adjusting the throttle opening, speed, etc., so as to control the reactive power output. When more reactive power is needed, the diesel generator system will increase the throttle opening, increase the speed, increase the excitation current, and output more reactive power; when less reactive power is needed, the opposite operation will be taken to achieve the regulation of the bus voltage.

[0068] SVG control system: The SVG control system sets the primary voltage regulation command of the SVG system through the SVG voltage set value. The SVG voltage set value is determined according to the main station voltage distribution command and the performance parameters of the SVG system, aiming to give full play to the fast and flexible reactive power regulation ability of the SVG.

[0069] The primary voltage regulation command of the SVG system and the SVG reactive power command are summarized, and the SVG actual reactive power command is generated while considering the SVG operation boundary conditions (such as the capacity, response speed, regulation range, compensation ability, and heat dissipation conditions of the SVG, etc.). According to the SVG actual reactive power command, the SVG adjusts the internal power electronic components, such as insulated gate bipolar transistors (IGBTs), etc., to quickly output or absorb reactive power. When the bus voltage is low, the SVG can quickly output reactive power to boost the bus voltage; when the bus voltage is high, the SVG can quickly absorb reactive power to lower the bus voltage, thereby achieving precise and fast regulation of the bus voltage.

[0070] S3: According to the secondary voltage regulation control strategy, comprehensively judge the parameters including frequency, tie-line power flow, voltage, and tie-line connection / disconnection at each of the measurement points, obtain the operation modes of each of the subsystems, and generate the dispatching AGC / AVC command according to the bus voltage set value and the actual bus voltage.

[0071] In this embodiment, step S3 is specifically as follows: At the measurement point of the voltage, parameters including frequency, tie-line power flow, voltage, and tie-line connection / disconnection are collected through sensors; The collected parameters are processed by using data analysis algorithms including a voltage harmonic analysis algorithm based on the discrete Fourier transform and a power flow calculation algorithm based on the power flow calculation equation to determine the reactive power distribution and tie-line power flow state of the power grid, and clarify the flow direction and magnitude of reactive power in the power grid; Based on the collected and processed parameters, combined with the pre-established operation model of the subsystem, judge the operation modes of each subsystem, where the operation model of the subsystem takes into account the physical characteristics and operation parameters of different types of subsystems including solar thermal, photovoltaic, energy storage, and diesel generation, and is dynamically updated according to the actual operation data; According to the deviation between the set value of the bus voltage and the actual bus voltage, a preliminary voltage regulation command is generated by using the proportional-integral (PI) control algorithm. The proportional coefficient Kp and the integral coefficient Ki are determined based on the electrical characteristics of the power grid and the voltage regulation response characteristics of each subsystem, such that the voltage regulation amount ΔU = Kp×(U_set - U_real)+ Ki×∫(U_set - U_real)dt, where U_set is the set voltage value and U_real is the actual voltage value; According to the voltage deviation and the requirements of reactive power balance in the power grid, a reactive power optimization algorithm based on the optimal power flow algorithm is used to generate the dispatching AGC / AVC command.

[0072] S4: After being adjusted by the adjustment coefficients of each subsystem, the dispatching AGC / AVC command is sent to each subsystem for voltage and reactive power regulation to maintain voltage stability.

[0073] In this embodiment, step S4 is specifically as follows: Each subsystem pre-sets the adjustment coefficient, which is determined according to the type, equipment performance, historical operation data and current operation state of each subsystem. Among them, the adjustment coefficient of the solar thermal system considers factors including the thermal efficiency of the energy storage system, the adjustment range and response speed of the steam turbine; the adjustment coefficient of the photovoltaic system considers factors including the conversion efficiency of the photovoltaic panel, the adjustment ability of the inverter and the light intensity; the adjustment coefficient of the energy storage system considers factors including the charge and discharge characteristics of the battery, the state of charge SOC and the charge and discharge power limit; the adjustment coefficient of the diesel generator system considers factors including the start-up time, output power range and fuel efficiency of the diesel generator set; the adjustment coefficient of the SVG control system considers factors including the capacity, response speed, adjustment range and compensation ability of the SVG; After receiving the adjusted command, the subsystem performs voltage and reactive power regulation operations according to the command. For the solar thermal system, by adjusting the steam inlet volume of the steam turbine or the heat release of the energy storage system, the excitation current of the generator is changed, and then the reactive power output is adjusted to achieve voltage regulation; the photovoltaic system adjusts the voltage and current operating points of the inverter to change its reactive power output to achieve voltage regulation; the energy storage system relies on controlling the charge and discharge power of the converter to change its own reactive power output, thereby affecting the voltage; the diesel generator system adjusts the throttle opening and speed of the diesel generator set, adjusts the excitation current of the generator, controls the reactive power output, and realizes voltage regulation. The SVG control system adjusts the internal power electronic components to change the output reactive power, and quickly outputs or absorbs reactive power according to the needs of the power grid, thereby regulating the voltage; And during the voltage and reactive power regulation process of each of the said subsystems, the regulation status information is fed back to the dispatching system in real time, and the dispatching system dynamically optimizes the said adjustment coefficients and instructions according to the feedback information to achieve precise voltage and reactive power control.

[0074] The real-time secondary voltage regulation control method for the high-altitude isolated network energy station in this embodiment further includes setting bus voltage control constraint conditions including bus and generator terminal voltage constraints, on-load tap-changer tap position constraints, and compensation capacitor bank switching capacity constraints, specifically as follows: The voltage is monitored through voltage transformers installed on the bus and at the generator terminals. When the bus or generator terminal voltage exceeds the set range, the reactive power is adjusted by means including the generator excitation system to control the voltage within the allowable range; The tap position of the on-load tap-changer is monitored using a tap position sensor. According to the bus voltage condition and the tap range, the tap position is adjusted in a timely manner under the premise of meeting the operation restrictions to assist in voltage regulation; The switching state and capacity of the compensation capacitor bank are monitored. Based on the voltage condition and the capacitor bank switching capacity constraint, the capacitor bank is switched within the allowable range to provide reactive power support for voltage regulation and ensure the stability of the bus voltage.

[0075] The following is a detailed explanation of the above technical solution; I. Bus and Generator Terminal Voltage Constraints Voltage Transformer Monitoring and Data Acquisition: The voltage transformer (PT) is a key device for realizing the monitoring of the bus and generator terminal voltages. It is carefully installed at specific positions on the bus and at the generator terminals to ensure accurate acquisition of voltage signals. These transformers have high precision and good stability, and can convert high voltages into low voltage signals (such as common 100V or lower) in proportion, so that subsequent measurement and processing equipment can receive and analyze them safely and reliably.

[0076] The collected voltage signals are transmitted to the control system in real time, and the data acquisition module in the control system samples, filters, and digitizes these signals to ensure that the acquired voltage data is accurate and real-time. For example, the data acquisition module may sample the voltage signals at a frequency of dozens of times per second or higher to capture the minute changes and transient fluctuations of the voltage, providing an accurate data basis for subsequent voltage judgment and control.

[0077] Judgment of Voltage Exceeding the Range and Adjustment Means: The control system will compare the collected bus and generator terminal voltages with the pre-set voltage range in real time. This setting range is determined based on the operating requirements of the power system, the rated parameters of the equipment, and the grid specifications. For example, for a specific plateau isolated grid energy station, the setting range of the bus voltage may be [34kV, 36kV], and the setting range of the generator terminal voltage may vary depending on the model and rated voltage of the generator, such as [10kV± 5%].

[0078] When the bus or generator terminal voltage is detected to be out of the set range, the control system will quickly start the adjustment mechanism. Among them, adjusting the generator excitation system is an important means. The generator excitation system adjusts the reactive power output of the generator by changing the magnitude of the excitation current. When the voltage is high, the control system will send a command to reduce the excitation current so that the generator absorbs more reactive power, thereby reducing the system voltage; conversely, when the voltage is low, the excitation current is increased to allow the generator to output more reactive power and increase the system voltage. This adjustment is carried out in real time and will be dynamically adjusted according to the size and change trend of the voltage deviation to control the voltage within the allowable range as soon as possible to ensure the stable operation of the power system and the safety of the equipment.

[0079] 2. Constraints on the tap position of on-load tap-changing transformers Tap position sensor and gear monitoring: On-load tap-changing transformers are equipped with special tap position sensors, which usually use advanced sensing technologies such as Hall effect sensors, photoelectric encoders, etc., to accurately detect the position changes of the taps. The sensors are installed on the tap changer mechanism of the transformer and work closely with the mechanical moving parts of the tap to obtain the current gear information of the tap in real time.

[0080] The sensor converts the position information of the tap into an electrical signal (such as voltage, current or digital signal) and transmits it to the control system through a cable or communication interface. The interface module in the control system receives these signals, decodes and processes them, and converts them into intuitive gear values ​​so that operators and control algorithms can understand the position status of the tap in real time. For example, the sensor may correspond each gear of the tap to a specific digital code, such as 001, 010, 100, etc. The control system determines which gear the tap is currently in based on the received code.

[0081] Gear adjustment strategy and operating restrictions: The control system formulates a tap adjustment strategy based on the real-time situation of the bus voltage and the tap position range. When the bus voltage deviates from the set value and cannot be effectively controlled within the range through other adjustment means (such as generator excitation regulation), the tap position of the on-load tap-changer transformer will be considered for adjustment. For example, if the bus voltage continues to be low, and there is still room for improvement in the current tap position (i.e., it has not reached the highest position), and other operating parameters of the transformer (such as oil temperature, load current, etc.) are within the allowable range, the control system will issue an instruction to adjust the tap to a higher position. This can increase the transformation ratio of the transformer and thus increase the bus voltage.

[0082] However, the adjustment of the tap is not carried out randomly, and there are a series of operation restrictions. First is the time interval limit for tap switching, which is to avoid excessive wear of the contacts caused by frequent tap switching, affecting the service life and reliability of the transformer. Generally, there needs to be an interval of a certain time between two adjacent tap switches, and this time interval depends on the type, specifications of the transformer and the manufacturer's recommendations, and may vary from a few minutes to dozens of minutes. Second is the switching times limit. Within a certain time period (such as one day, one week, etc.), the number of tap switches is limited to prevent damage to the transformer caused by excessive operation. In addition, the load condition of the transformer needs to be considered. Under heavy load conditions, the adjustment of the tap may have a greater impact on the operation of the transformer, so it needs to be operated carefully to avoid overloading or other abnormal conditions of the transformer caused by tap adjustment. When making tap position adjustment, the control system will comprehensively consider these factors to ensure that the tap position is adjusted timely and reasonably on the premise of meeting the operation restrictions to assist in regulating the bus voltage.

[0083] III. Constraints on the switching capacity of the compensation capacitor bank Comprehensiveness of the state monitoring of the capacitor bank: The monitoring of the switching state and capacity of the compensation capacitor bank is a multi-faceted process. For the switching state, it is achieved through the auxiliary contacts installed on the capacitor bank switching equipment (such as circuit breakers, contactors, etc.) or the state monitoring function of intelligent switches. These auxiliary contacts or intelligent switches can convert the opening and closing state of the switch into an electrical signal in real time and transmit it to the control system. The state monitoring module in the control system will receive these signals in real time and accurately judge whether the capacitor bank is in the switched-in state or the switched-out state.

[0084] Meanwhile, it is also necessary to monitor the electrical parameters of the capacitor bank, including current, voltage, etc. By installing current transformers and voltage transformers in the capacitor bank circuit, current and voltage signals are collected in real time and transmitted to the control system. The control system uses these signals to calculate the actual reactive power output of the capacitor bank, and then estimates the actual capacity of the capacitor bank. In addition, parameters such as the temperature and harmonic content of the capacitor bank are also monitored, because these factors will affect the performance and lifespan of the capacitor bank, and thus affect its role in voltage regulation. For example, too high a temperature may cause the insulation performance of the capacitor to decline, and too high a harmonic content may cause the capacitor to be overloaded or resonate, which will have an adverse impact on the normal operation and voltage regulation function of the capacitor bank.

[0085] Switching control and capacity constraint: The control system will determine the switching operation of the capacitor bank based on factors such as the real-time situation of the bus voltage, the reactive power demand of the system, and the current state of the capacitor bank. When the bus voltage is lower than the set value and the system needs to increase reactive power, the control system will first check whether the capacity of the currently connected capacitor bank has reached the maximum allowable connected capacity. If not, and there is a suitable capacitor bank available for connection (i.e., meeting the conditions such as the priority and operating status of the capacitor bank), then an instruction will be issued to connect the corresponding capacitor bank to provide reactive power support and boost the bus voltage.

[0086] The maximum allowable connected capacity is determined based on factors such as the rated parameters of the capacitor bank, the design requirements of the system, and the operating specifications of the power grid. For example, the total capacity of a group of capacitor banks is 10 Mvar, but considering the stability and safety of the system, the maximum allowable connected capacity may be set to 8 Mvar to avoid problems such as voltage rise and harmonic amplification caused by overcompensation. Similarly, when the bus voltage is too high and reactive power needs to be reduced, the control system will disconnect some or all of the capacitor banks according to the current situation of the connected capacitor banks, but ensure that the capacity of the connected capacitor banks after disconnection is not lower than the minimum allowable connected capacity. The setting of the minimum allowable connected capacity is to ensure that the capacitor bank can play a certain role in reactive power compensation in the system, and at the same time avoid damage to the capacitor bank and switching equipment caused by frequent switching. During the process of switching the capacitor bank, the control system will strictly follow these capacity constraint conditions to ensure that the switching operation of the capacitor bank can not only meet the voltage regulation requirements but also ensure the safe and stable operation of the system.

[0087] Second Embodiment As Figure 4 shown, this embodiment provides a real-time secondary voltage regulation control system for a high-altitude isolated power grid energy station for implementing the real-time secondary voltage regulation control method of the high-altitude isolated power grid energy station in the first embodiment, including: The actual bus voltage acquisition module 1 is configured to acquire the voltage values of several measurement points on the bus according to the electrical quantity acquisition device, and optimize the voltage values of the measurement points based on the power grid topology identification situation to obtain the optimized bus voltage value as the actual bus voltage; The voltage regulation control strategy acquisition module 2 is configured to preset the bus voltage setting value, and calculate the master station voltage distribution instruction and the dispatching reactive power distribution instruction according to the bus voltage setting value and the actual bus voltage according to different operation modes, and distribute the voltage to each subsystem for adjustment to form a real-time secondary voltage regulation control strategy; The subsystem dispatching instruction generation module 3 is configured to comprehensively judge the parameters of each of the measurement points including frequency, tie line power flow, voltage, and tie line connection and disconnection according to the secondary voltage regulation control strategy, obtain the operation modes of each subsystem, and generate a dispatching AGC / AVC instruction according to the bus voltage setting value and the actual bus voltage; The subsystem power regulation execution module 4 is configured to send the dispatching AGC / AVC instruction to each subsystem for voltage and reactive power regulation after being adjusted by the adjustment coefficient of each subsystem to maintain voltage stability.

[0088] A computer-readable storage medium stores computer code, and when the computer code is executed, the above method is executed. Those of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing relevant hardware through a program, and this program can be stored in a computer-readable storage medium. The storage medium may include: read-only memory (ROM, Read Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disc, etc.

[0089] The above is only the preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the idea of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, several improvements and refinements made without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

[0090] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0091] It should be noted that the above embodiments can be freely combined as needed. The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A real-time secondary voltage regulation control method for a plateau isolated grid energy station, characterized in that: The following steps are involved: S1: The voltage values ​​of several measuring points on the bus are collected by the electrical quantity collection device, and the voltage values ​​of the measuring points are optimized according to the grid topology recognition situation to obtain the bus voltage optimization value as the bus actual voltage; S2: presetting the bus voltage setting value, calculating the master station voltage distribution instruction and the dispatching reactive power distribution instruction according to the bus voltage setting value and the actual bus voltage according to different operation modes, distributing the voltage to each subsystem for adjustment, and forming a real-time secondary voltage regulation control strategy; S3: According to the secondary voltage regulation control strategy, comprehensively judge the parameters of each of the measurement points including frequency, tie line flow, voltage, and tie line shutdown, obtain the operation mode of each of the subsystems, and generate a dispatching AGC / AVC instruction according to the bus voltage set value and the bus actual voltage; S4: The scheduling AGC / AVC instruction is sent to each subsystem for voltage and reactive power regulation after being adjusted by the adjustment coefficient of each subsystem to maintain voltage stability.

2. The real-time secondary voltage regulation control method for plateau isolated grid energy station according to claim 1 is characterized in that: In step S1, the voltage values ​​of several measuring points on the bus are collected by the electrical quantity collection device, and the voltage values ​​of the measuring points are optimized according to the grid topology recognition situation to obtain the bus voltage optimization value as the bus actual voltage, which is specifically: Collect the PT signal on the bus line according to the electrical quantity collection device, including the voltage value of the measuring point including the bus voltage of the energy collection station, the bus voltage of the solar thermal power station, and the bus voltage of the photovoltaic power station; When the voltage values ​​are all normal, the higher value among the bus collection voltage of the energy collection station, the bus collection voltage of the solar thermal power station, and the bus collection voltage of the photovoltaic power station is taken as the preferred value of the bus voltage; When a voltage value at any of the measurement points fails, the preferred value of the bus voltage is obtained in the following order: When the solar thermal unit is in operation, the preferred value of the bus voltage is obtained in the order of the bus collection voltage of the energy collection station, the bus collection voltage of the solar thermal power station, and the bus collection voltage of the photovoltaic power station; when the solar thermal unit is not in operation, the preferred value of the bus voltage is obtained in the order of the bus collection voltage of the energy collection station, the bus collection voltage of the photovoltaic power station, and the bus collection voltage of the solar thermal power station.

3. The real-time secondary voltage regulation control method for plateau isolated grid energy station according to claim 1 is characterized in that: In step S2, when the operation mode is solar thermal + solar energy storage and diesel mode, the voltage distribution instruction of the master station and the dispatching reactive power distribution instruction are calculated, and the voltage is distributed to each subsystem for adjustment to form a real-time secondary voltage regulation control strategy, which is specifically: Obtain the bus voltage setting value and the bus actual voltage, and respectively calculate the master station voltage allocation instruction and the dispatch reactive power allocation instruction, wherein the master station voltage allocation instruction is generated according to the bus voltage setting value and the deviation value of the bus actual voltage, combined with the voltage regulation characteristics and control strategy of the system, the master station voltage allocation instruction=Kp×voltage deviation+Ki×∫voltage deviation dt, Kp is the proportional coefficient, Ki is the integral coefficient, the dispatch reactive power allocation instruction is based on the voltage deviation, combined with the voltage-reactive power characteristic curve to calculate the reactive power adjustment amount, and the dispatch reactive power allocation instruction is generated according to the reactive power adjustment amount; The master station voltage distribution instruction provides a reference for the voltage setting of the subsystems including solar thermal voltage setting, energy storage voltage setting, photovoltaic fast power voltage setting, diesel generator voltage setting, and SVG voltage setting according to the characteristics of different subsystems; The dispatching reactive power distribution instruction is allocated into reactive power instructions including energy storage reactive power instructions, photovoltaic reactive power instructions, diesel generator reactive power instructions and SVG reactive power instructions according to the characteristics of each of the subsystems and their role in voltage regulation, combined with boundary conditions including energy storage operation boundary conditions, photovoltaic operation boundary conditions, diesel generator operation boundary conditions and SVG operation boundary conditions; The solar thermal system calculates the voltage deviation of the solar thermal system through the solar thermal voltage setting and the outlet voltage of the solar thermal unit, and calculates the solar thermal reactive power instruction through the voltage deviation of the solar thermal system; The energy storage system sets an energy storage primary voltage regulation instruction through the energy storage voltage setting, and the energy storage primary voltage regulation instruction and the energy storage reactive power instruction are aggregated to generate an energy storage actual reactive power instruction; The photovoltaic system sets a photovoltaic fast power primary voltage regulation instruction through the photovoltaic fast power voltage setting, and the photovoltaic fast power primary voltage regulation instruction is aggregated with the photovoltaic reactive power instruction to generate a photovoltaic actual reactive power instruction; The diesel generator system sets a primary voltage regulation command of the diesel generator system through the diesel generator voltage setting, and the primary voltage regulation command of the diesel generator system is aggregated with the diesel generator reactive power command to generate an actual diesel generator reactive power command; The SVG control system sets a primary voltage regulation instruction of the SVG system through the SVG voltage setting, and the primary voltage regulation instruction of the SVG system is aggregated with the SVG reactive power instruction to generate an SVG actual reactive power instruction.

4. The real-time secondary voltage regulation control method for plateau isolated grid energy station according to claim 1 is characterized in that: In step S2, when the operation mode is the solar-storage-diesel mode, the voltage distribution instruction of the master station and the dispatching reactive power distribution instruction are calculated, and the voltage is distributed to each subsystem for adjustment to form a real-time secondary voltage regulation control strategy, which is specifically: Obtain the bus voltage setting value and the bus actual voltage, and respectively calculate the master station voltage allocation instruction and the dispatch reactive power allocation instruction, wherein the master station voltage allocation instruction is generated according to the bus voltage setting value and the deviation value of the bus actual voltage, combined with the voltage regulation characteristics and control strategy of the system, the master station voltage allocation instruction=Kp×voltage deviation+Ki×∫voltage deviation dt, Kp is the proportional coefficient, Ki is the integral coefficient, the dispatch reactive power allocation instruction is based on the voltage deviation, combined with the voltage-reactive power characteristic curve to calculate the reactive power adjustment amount, and the dispatch reactive power allocation instruction is generated according to the reactive power adjustment amount; The master station voltage distribution instruction provides a reference for the voltage setting of the subsystems including energy storage voltage setting, photovoltaic fast power voltage setting, diesel generator voltage setting, and SVG voltage setting according to the characteristics of different subsystems; The dispatching reactive power distribution instruction is allocated into reactive power instructions including PV reactive power instructions, diesel generator reactive power instructions and SVG reactive power instructions according to the characteristics of each of the subsystems and their role in voltage regulation, combined with boundary conditions including PV operation boundary conditions, diesel generator operation boundary conditions and SVG operation boundary conditions; The energy storage system calculates the energy storage system voltage deviation through the energy storage voltage setting and the actual voltage of the energy storage system, and calculates the energy storage reactive power instruction through the energy storage system voltage deviation; The photovoltaic system sets a photovoltaic fast power primary voltage regulation instruction through the photovoltaic fast power voltage setting, and the photovoltaic fast power primary voltage regulation instruction is aggregated with the photovoltaic reactive power instruction to generate a photovoltaic actual reactive power instruction; The diesel generator system sets a primary voltage regulation command of the diesel generator system through the diesel generator voltage setting, and the primary voltage regulation command of the diesel generator system is aggregated with the diesel generator reactive power command to generate an actual diesel generator reactive power command; The SVG control system sets a primary voltage regulation instruction of the SVG system through the SVG voltage setting, and the primary voltage regulation instruction of the SVG system is aggregated with the SVG reactive power instruction to generate an SVG actual reactive power instruction.

5. The real-time secondary voltage regulation control method for plateau isolated grid energy station according to claim 1 is characterized in that: In step S3, according to the secondary voltage regulation control strategy, the parameters of each of the measurement points including frequency, tie line flow, voltage, and tie line shutdown are comprehensively judged to obtain the operation mode of each of the subsystems, and the dispatching AGC / AVC instruction is generated according to the bus voltage set value and the bus actual voltage, specifically: At the voltage measurement point, parameters including frequency, tie line flow, voltage and tie line shutdown are collected by sensors; The collected parameters are processed using data analysis algorithms including voltage harmonic analysis algorithm based on discrete Fourier transform and power flow calculation algorithm based on power flow calculation equation to determine the reactive power distribution and tie line power flow state of the power grid, and clarify the flow direction and size of reactive power in the power grid; According to the collected and processed parameters, combined with the pre-established subsystem operation model, the operation mode of each subsystem is determined, wherein the subsystem operation model takes into account the physical characteristics and operation parameters of different types of subsystems including solar thermal, photovoltaic, energy storage, and diesel generation, and is dynamically updated according to the actual operation data; According to the bus voltage set value and the deviation of the bus actual voltage, a proportional integral PI control algorithm is used to generate a preliminary voltage regulation instruction, and the proportional coefficient Kp and the integral coefficient Ki are determined according to the electrical characteristics of the power grid and the voltage regulation response characteristics of each subsystem, so that the voltage regulation amount ΔU =Kp×(U_set-U_real)+ Ki×∫(U_set-U_real)dt, where U_set is the voltage set value and U_real is the actual voltage value; According to the voltage deviation and the reactive power balance requirements of the power grid, the reactive power optimization algorithm based on the optimal power flow algorithm is used to generate the dispatching AGC / AVC instructions.

6. The real-time secondary voltage regulation control method for plateau isolated grid energy station according to claim 1 is characterized in that: In step S4, the scheduling AGC / AVC instruction is sent to each subsystem for voltage and reactive power regulation after being adjusted by the adjustment coefficient of each subsystem to maintain voltage stability, specifically: Each of the subsystems pre-sets the adjustment coefficient, and the adjustment coefficient is determined according to the type, equipment performance, historical operation data and current operation status of each of the subsystems. The adjustment coefficient of the solar thermal system takes into account factors including the thermal efficiency of the heat storage system, the adjustment range and response speed of the steam turbine; the adjustment coefficient of the photovoltaic system takes into account factors including the conversion efficiency of the photovoltaic panel, the adjustment capability of the inverter and the light intensity; the adjustment coefficient of the energy storage system takes into account factors including the charge and discharge characteristics of the battery, the state of charge SOC and the charge and discharge power limit; the adjustment coefficient of the diesel generator system takes into account factors including the start-up time, output power range and fuel efficiency of the diesel generator set; the adjustment coefficient of the SVG control system takes into account factors including the capacity, response speed, adjustment range and compensation capability of the SVG; After receiving the adjusted instructions, the subsystem performs voltage and reactive power regulation operations according to the instructions. For the solar thermal system, the excitation current of the generator is changed by adjusting the steam intake of the steam turbine or the heat release of the heat storage system, and then the reactive power output is adjusted to achieve voltage regulation; the photovoltaic system changes its reactive power output by adjusting the voltage and current operating points of the inverter to achieve the purpose of voltage regulation; the energy storage system changes its own reactive power output by controlling the charging and discharging power of the converter, thereby affecting the voltage; the diesel generator system adjusts the throttle opening and speed of the diesel generator set, adjusts the excitation current of the generator, controls the reactive power output, and achieves voltage regulation; the SVG control system changes the output reactive power by adjusting the internal power electronic components, and quickly outputs or absorbs reactive power according to the needs of the power grid, thereby adjusting the voltage; In addition, during the voltage and reactive power regulation process, each of the subsystems feeds back regulation status information to the dispatching system in real time. The dispatching system dynamically optimizes the adjustment coefficients and instructions based on the feedback information to achieve accurate voltage and reactive power control.

7. The real-time secondary voltage regulation control method for plateau isolated grid energy station according to claim 1 is characterized in that: It also includes setting bus voltage control constraints including bus and generator terminal voltage constraints, on-load tap changer transformer tap position constraints, and compensation capacitor bank switching capacity constraints, specifically: The voltage is monitored by voltage transformers installed at the busbar and generator terminals. When the voltage at the busbar or generator terminal exceeds the set range, the reactive power is adjusted by adjusting means including the generator excitation system to control the voltage within the allowable range. The tap position sensor of the on-load tap-changing transformer is used to monitor the gear position. According to the bus voltage and the tap gear range, the tap gear position is adjusted in time to assist in regulating the voltage while meeting the operating restrictions; Monitor the switching-on / off status and capacity of the compensation capacitor group. According to the voltage conditions and the switching capacity constraints of the capacitor group, switch the capacitor group within the allowable range to provide reactive support for voltage regulation and ensure bus voltage stability.

8. A real-time secondary voltage regulation control system for a plateau isolated power grid energy station for executing the real-time secondary voltage regulation control method for a plateau isolated power grid energy station as described in any one of claims 1 to 7, characterized in that: include: The busbar actual voltage acquisition module is used to collect the voltage values ​​of several measuring points on the busbar according to the electrical quantity acquisition device, optimize the voltage values ​​of the measuring points according to the grid topology recognition situation, and obtain the busbar voltage optimization value as the busbar actual voltage; The voltage regulation control strategy acquisition module is used to pre-set the bus voltage setting value, calculate the master station voltage distribution instruction and the dispatch reactive power distribution instruction according to the bus voltage setting value and the actual bus voltage according to different operation modes, distribute the voltage to each subsystem for adjustment, and form a real-time secondary voltage regulation control strategy; A subsystem dispatch instruction generation module is used to comprehensively judge the parameters of each of the measurement points including frequency, tie line flow, voltage, and tie line shutdown according to the secondary voltage regulation control strategy, obtain the operation mode of each of the subsystems, and generate a dispatch AGC / AVC instruction according to the bus voltage set value and the bus actual voltage; The subsystem power regulation execution module is used to provide the scheduling AGC / AVC instructions to each subsystem for voltage and reactive power regulation after being adjusted by the adjustment coefficient of each subsystem to maintain voltage stability.

9. A computer device comprising a memory and one or more processors, wherein the memory stores computer codes, and when the computer codes are executed by the one or more processors, the one or more processors execute the method according to any one of claims 1 to 7. 10 . A computer-readable storage medium storing a computer code. When the computer code is executed, the method according to claim 1 is executed.

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