Automatic topology identification method and system for plateau isolated network energy station

Abstract

The invention relates to the technical field of automatic topology identification, and provides an automatic topology identification method for a plateau isolated network energy station, which comprises the following steps: S1, monitoring the real-time operation states of a main transformer incoming line, a photovoltaic pooling station, an energy storage incoming line and a standby transformer outgoing line to obtain the operation information of a photo-thermal unit, a photovoltaic unit, an energy storage power station and a diesel generator unit; comprehensively judging the operation mode of the power grid; s2, switching an operation mode state machine of the plateau isolated network energy station system according to the judged operation mode of the power grid, and controlling each subsystem by adopting a control model matched with the operation mode in each different operation mode; s3, performing adjustable resource identification according to the judged operation mode of the power grid and the characteristics of the power supply; and S4, according to an adjustable resource identification result, setting a control strategy of each subsystem serving as a power supply point. The system operation mode and adjustable resources of the energy station can be accurately identified in real time, and efficient coordination of sources, networks, loads and storage is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic topology recognition, and in particular to an automatic topology recognition method and system for a plateau isolated grid energy station. Background Art

[0002] The Zabuye Salt Lake Lithium Extraction Project is located in a plateau and remote area, with high fossil energy costs and weak grid support capabilities. However, the load of the lithium carbonate processing plant is stable, the power outage losses are within an acceptable range, and the local solar energy resources are abundant and the land resources are sufficient. It is economically reasonable to build an independent power grid based on new energy to power the processing plant. Thus, the "Zhabuye Source-Grid-Load-Storage Integrated Energy Supply Project" (Energy Station) was born. The energy station covers energy collection stations, energy dispatching centers, solar thermal systems, photovoltaic systems, and electrochemical energy storage systems. It is a thermal power integrated energy system that integrates power supply, load, energy storage, power distribution, and control systems. It needs to rely on the coordinated operation of "source, grid, load, and storage" to provide stable electricity and steam for the lithium carbonate processing plant.

[0003] In terms of operating mode identification, traditional technologies mostly rely on manual experience and simple monitoring equipment to judge the system operating mode. They are unable to obtain real-time and accurate electrical quantity signals and switch status information of key parts such as grid-connected interconnection lines, power supply points, in-plant power grid busbars, bus-tie switches, generator outlets, etc., resulting in serious lags in the identification of system operating modes. For example, when the power grid topology changes, it is often impossible to promptly detect whether it is in grid-connected operation, island operation, or partial island operation, which in turn affects the stable operation and optimized scheduling of the entire energy station.

[0004] Existing methods are unable to comprehensively consider various complex working conditions and equipment combinations. They are not accurate enough in identifying the operating modes of multiple energy systems such as solar thermal, photovoltaic, and energy storage when they work in coordination. They are also unable to accurately judge key information such as power interaction and energy flow direction between systems, which can easily lead to energy waste and inefficient system operation.

[0005] In terms of adjustable resource identification, there is a lack of effective technical means to monitor and analyze the commissioning information and operating status of each power source in real time, and it is impossible to dynamically identify adjustable resources according to changes in the network topology. For example, when the output of a solar thermal system changes due to changes in light intensity or equipment failure, or when the photovoltaic system is affected by weather and other factors, the adjustment capacity and range of adjustable resources such as energy storage systems cannot be determined in a timely and accurate manner, making it difficult to achieve effective regulation of the grid frequency and voltage, affecting power quality and system stability.

[0006] There is insufficient understanding of the characteristics and interrelationships of adjustable resources under different operating modes, and the potential of each adjustable resource cannot be fully tapped for coordinated optimization. For example, in different modes such as independent load operation of solar thermal or combined operation of solar and energy storage, it is impossible to accurately identify the best coordination and regulation strategy when solar thermal and energy storage are the main resources for frequency and voltage regulation, resulting in insufficient resource utilization and increased system operating costs. Summary of the invention

[0007] In view of the above problems, the purpose of the present invention is to provide an automatic topology identification method and system for plateau isolated grid energy stations, which can accurately identify the operation mode and adjustable resources of the energy station system in real time, and realize efficient coordination of "source, grid, load and storage".

[0008] The above-mentioned object of the present invention is achieved through the following technical solutions: An automatic topology identification method for a plateau isolated grid energy station comprises the following steps: S1: By monitoring the real-time operating status of key interconnection lines including the main transformer incoming line, photovoltaic collection station, energy storage incoming line, and standby transformer outgoing line, the operation information of subsystems including solar thermal units, photovoltaic units, energy storage power stations, and diesel generators is obtained, and the operation mode of the power grid is comprehensively judged; S2: switching the operation mode state machine of the plateau isolated grid energy station system according to the determined operation mode of the power grid, and controlling each of the subsystems in each different operation mode using a control model matching the operation mode; S3: Identify adjustable resources according to the determined operation mode of the power grid and the characteristics of the power source, and set the main frequency and voltage regulating power source under each operation mode; S4: According to the result of the identification of the adjustable resources, the control strategy of each of the subsystems serving as power supply points is set.

[0009] Furthermore, in step S1, by monitoring the real-time operating status of key interconnection lines including the main transformer incoming line, photovoltaic collection station, energy storage incoming line, and standby transformer outgoing line, the operation information of subsystems including the solar thermal unit, photovoltaic unit, energy storage power station, and diesel generator unit is obtained, and the operation mode of the power grid is comprehensively judged, specifically: A current transformer, a voltage transformer and a power sensor are installed at the inlet of the main transformer to collect electrical quantity data including three-phase current, voltage, active power and reactive power transmitted by the solar thermal unit to the power grid in real time; Install current transformers, voltage transformers and power sensors at the incoming line position of the photovoltaic collection station to collect the current, voltage and power transmitted by the photovoltaic unit to the power grid in real time, and install light intensity sensors to monitor the light intensity in the area where the photovoltaic unit is located in real time, so as to provide a reference for the subsequent analysis of the operating status of the photovoltaic unit; A current transformer, a voltage transformer and a power sensor are installed at the energy storage inlet to collect the energy exchange between the energy storage system and the power grid, including the charging current, discharging current, charging power and discharging power, in real time, and a status monitoring device of the energy storage system is used to obtain information of the energy storage system, including the state of charge SOC and the state of health SOH; A current transformer, a voltage transformer and a power sensor are installed at the outlet of the start-up transformer to collect electrical quantity data including current, voltage, active power and reactive power transmitted by the solar thermal unit to the power grid in real time; The collected data is transmitted to a central control system, and the central control system performs pre-processing on the data including data verification, filtering, and format conversion; Through comprehensive judgment of the collected data, the following three power grid operation combinations are obtained: Mode 1: Solar thermal & solar energy storage operation, the power supply points are: solar thermal + photovoltaic + energy storage + diesel generation / external grid supplement; Method 2: Energy storage operates independently, and the power supply points are: energy storage + photovoltaic + diesel generation / external grid energy supplement; Method three: Solar thermal power operates independently with load, and the power supply points are: solar thermal power + photovoltaic power + diesel power generation.

[0010] Further, in step S2, the operation mode state machine of the plateau isolated grid energy station system is switched according to the determined operation mode of the power grid, specifically: The initial state of the grid is in the CSP & PV storage operation mode, that is, the CSP unit has power interaction with the grid, the PV unit generates electricity normally, the energy storage power station discharges according to grid demand, the diesel generator unit is in standby state, and the external grid performs power supplement. In this state, various subsystems work together to maintain stable operation of the grid and meet load demand; When the CSP unit is unable to supply power to the grid due to equipment failure or insufficient light, the PV unit still generates electricity under light conditions, and the discharge power of the energy storage power station is adjusted to ensure the stability of the total power supply of the grid. At the same time, the diesel generator set is in standby mode, and the external grid is used for power supplement; When the energy storage power station stops discharging due to power exhaustion or its own fault, the discharge power of the solar thermal unit is adjusted to ensure the stability of the total power supply of the power grid. The photovoltaic unit is still generating electricity under the light condition. At the same time, the diesel generator set is in standby state and the external network is used for power supplement; When the power grid encounters an emergency situation including a sudden and substantial increase in load, a sharp drop in power grid frequency or voltage, or a serious failure of any of the subsystems resulting in a serious shortage of power supply and a complete shutdown due to an accident, the diesel engine emergency start is triggered; When the system stops completely due to an accident and power supply needs to be restored, and the energy storage power station has the black start capability, the energy storage black start is triggered.

[0011] Further, in step S2, each of the subsystems is controlled in each of the different operation modes using a control model that matches the operation mode, specifically: Method 1: Solar thermal and solar energy storage operation Solar thermal systems: frequency and voltage droop modes; Energy storage system: grid-connected mode; Asynchronous interconnection: active response mode; Photovoltaic system: constant power mode; SVG system: AVC mode; Diesel generator system: Mains mode; Method 2: Independent operation of energy storage Solar thermal system: shutdown; Energy storage system: off-grid mode; Asynchronous interconnection: active response mode; Photovoltaic system: constant power mode; SVG system: AVC mode; Diesel generator system: mains mode; Method 3: Solar thermal power independent load operation Solar thermal system: single machine frequency modulation mode; Energy storage system: shutdown; Asynchronous interconnection: outage; Photovoltaic system: constant power mode; SVG system: AVC mode; Diesel generator system: Mains mode.

[0012] Further, in step S3, according to the determined operation mode of the power grid and the characteristics of the power supply, the main frequency-regulated and voltage-regulated power supply in each operation mode is set, specifically: Method 1: CSP & PV-storage operation, with CSP as the main frequency and voltage regulator; Method 2: Energy storage operates independently, and energy storage serves as the main frequency and voltage regulator; Method three: Solar thermal operates independently with load, and solar thermal is used as the main force for frequency and voltage regulation.

[0013] Furthermore, in step S4, according to the result of the adjustable resource identification, the control strategy of each of the subsystems serving as power supply points is set, specifically: Method 1: Solar thermal and solar energy storage operation Main frequency modulation equipment: photothermal; Main voltage regulating equipment: solar thermal; Photovoltaic operation mode: MPPT+droop; Diesel generator operation mode: droop; SVG operation mode: droop; Voltage source during low-breakthrough process: solar thermal + diesel generation; Method 2: Independent operation of energy storage When diesel generator power is included: Main frequency regulation equipment: energy storage; Main voltage regulating equipment: energy storage; Photovoltaic operation mode: pressure output + droop; Diesel generator operation mode: droop; SVG operation mode: droop; Voltage source during low-voltage break-through: energy storage + diesel generator; When diesel generator power generation is not included: Main frequency regulation equipment: energy storage; Main voltage regulating equipment: energy storage; Photovoltaic operation mode: pressure output + droop; Diesel generator operation mode: None; SVG operation mode: droop; Voltage source of low wear process: energy storage; Method 3: Solar thermal power independent load operation Main frequency modulation equipment: photothermal; Main voltage regulating equipment: solar thermal; Photovoltaic operation mode: MPPT+droop; Diesel generator operation mode: droop; SVG operation mode: droop; Voltage source during low-breakthrough process: solar thermal + diesel generation; Furthermore, the automatic topology identification method of the plateau isolated grid energy station also includes: Based on the identification of the adjustable resources, the subsystems that need to be controlled for real-time secondary frequency regulation and secondary voltage regulation are determined, and corresponding control instructions are issued. At the same time, when switching between the multiple operation modes, the switching process is ensured to be disturbance-free by real-time monitoring of the grid parameters and using a preset smooth switching algorithm, so as to ensure the stability of the grid; The preset smooth switching algorithm includes a switching algorithm based on power balance, a switching algorithm based on voltage phase synchronization, and a switching algorithm based on frequency tracking.

[0014] An automatic topology identification system for plateau isolated power grid energy stations for executing the automatic topology identification method for plateau isolated power grid energy stations as described above, comprising: The system operation mode identification module is used to monitor the real-time operation status of key interconnection lines including the main transformer incoming line, photovoltaic collection station, energy storage incoming line, and standby transformer outgoing line, obtain the commissioning information of subsystems including solar thermal units, photovoltaic units, energy storage power stations, and diesel generators, and comprehensively determine the operation mode of the power grid; An operation mode state machine switching module is used to switch the operation mode state machine of the plateau isolated grid energy station system according to the determined operation mode of the power grid, and to control each of the subsystems in each different operation mode using a control model matching the operation mode; A system adjustable resource identification module, used to identify adjustable resources according to the determined operation mode of the power grid and the characteristics of the power supply, and set the main frequency and voltage regulating power supply under each operation mode; The subsystem control strategy setting module is used to set the control strategy of each of the subsystems serving as power supply points according to the result of the adjustable resource identification.

[0015] A computer device comprises 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 above method.

[0016] A computer-readable storage medium stores computer codes. When the computer codes are executed, the above method is executed.

[0017] Compared with the prior art, the present invention has at least one of the following beneficial effects: (1) Improving the stability and reliability of power grid operation Accurate operation mode identification and switching: Through real-time monitoring of key interconnection lines and acquisition of subsystem commissioning information, the grid operation mode can be accurately determined and seamlessly switched according to the preset state machine. For example, when the solar thermal unit cannot supply power due to a fault or insufficient light, the operation status of the energy storage power station and the photovoltaic unit can be adjusted in time to ensure the stability of the total power supply of the grid and avoid power outages caused by operation mode switching. This significantly improves the stability of the grid under various working conditions, ensures the continuous power supply of important loads such as lithium carbonate processing plants, and reduces the risk of production losses and equipment damage caused by power outages.

[0018] Strong emergency response and fault recovery capabilities: When an emergency occurs in the power grid, such as a sudden increase in load, a sudden drop in frequency and voltage, or a serious subsystem failure, the diesel engine can be quickly triggered to start in an emergency, replenish power in time, and maintain the stability of the power grid. In addition, after a complete shutdown due to an accident, if the energy storage power station has the ability to start in black, it can quickly start and gradually restore other equipment, shortening the power outage time, enhancing the power grid's ability to respond to sudden failures and natural disasters, and improving the reliability of the entire energy station system.

[0019] (2) Optimizing energy utilization and system efficiency Matching of operation mode and control model: For different operation modes, a matching control model is set for each subsystem. For example, in the CSP & PV storage operation mode, the CSP system adopts frequency and voltage droop mode, which can flexibly adjust power and voltage according to grid demand; the energy storage system is in grid-connected mode, which can effectively smooth power fluctuations; the photovoltaic system constant power mode can maximize the use of solar energy resources. This refined control method enables each subsystem to operate efficiently under different working conditions, give full play to their respective advantages, improve energy utilization efficiency, reduce energy waste, and reduce operating costs.

[0020] Identification and reasonable configuration of adjustable resources: Accurately identify adjustable resources according to the grid operation mode and power supply characteristics, and set the main frequency and voltage regulation power supply. For example, in the CSP & PV storage operation and CSP independent load operation modes, CSP is used as the main frequency and voltage regulation power supply, which can quickly respond to grid frequency and voltage changes by using its thermal inertia and energy storage capacity; when energy storage is operated independently, energy storage is used as the main frequency and voltage regulation power supply, which stabilizes the grid with its fast charging and discharging characteristics. By reasonably configuring adjustable resources, optimal scheduling and coordinated control of energy are achieved, further improving the overall efficiency of the system.

[0021] (3) Enhance the power quality and adaptability of the power grid Multiple control strategies to ensure power quality: Detailed control strategies are set for subsystems in different operating modes, including photovoltaic operation mode (MPPT + droop, output pressure + droop, etc.), diesel operation mode (droop), SVG operation mode (AVC mode), etc. These control strategies can effectively adjust the active power, reactive power, frequency and voltage of the power grid to ensure that the power quality meets the requirements. For example, the AVC mode of the SVG system can compensate for reactive power in real time and maintain the stability of the grid voltage; the droop characteristics of the photovoltaic system can automatically adjust the output power when the grid voltage changes, and assist in stabilizing the grid. This provides users with high-quality electricity and meets the strict requirements of various precision equipment and production processes for power quality.

[0022] Adapt to complex working conditions and environmental changes: The environment of isolated energy stations on the plateau is complex, with large changes in factors such as light and temperature, and the grid structure is relatively weak. This method can quickly adapt to various working condition changes and environmental factors through real-time topology identification, operation mode switching and adjustable resource control. Whether it is a fluctuation in light intensity, equipment failure or sudden change in load, it can respond and adjust in time to ensure the stable operation of the power grid in a complex environment, and improve the adaptability and anti-interference ability of the energy station to the special environment of the plateau. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is an overall flow chart of the automatic topology identification method of the plateau isolated grid energy station of the present invention; Figure 2 It is a schematic diagram of the state machine of the system operation mode of the present invention; Figure 3 This is the overall structural diagram of the automatic topology identification system of the plateau isolated grid energy station of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0025] Those skilled in the art will appreciate that, unless otherwise stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present invention refers to the presence of the 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 groups thereof.

[0026] First embodiment like Figure 1 As shown, this embodiment provides an automatic topology identification method for a plateau isolated grid energy station, comprising the following steps: S1: By monitoring the real-time operating status of key interconnection lines including the main transformer incoming line, photovoltaic collection station, energy storage incoming line, and standby transformer outgoing line, the operation information of subsystems including solar thermal units, photovoltaic units, energy storage power stations, and diesel generators is obtained, and the operation mode of the power grid is comprehensively judged.

[0027] By real-time monitoring of the real-time operating status of key interconnection lines such as "main transformer incoming line", "standby transformer outgoing line", "energy storage incoming line 1", and "photovoltaic collection station incoming line", the commissioning information of solar thermal units, diesel generators, energy storage power stations, and photovoltaic power stations can be monitored to comprehensively judge the operating mode of the power grid, and judge the status of the power station being off-grid, operating in a local island, etc. And through the comprehensive judgment of the above information, the operating combination of the power grid can be obtained. The specific technical solution is as follows: A current transformer, a voltage transformer and a power sensor are installed at the inlet of the main transformer to collect electrical quantity data including three-phase current, voltage, active power and reactive power transmitted by the solar thermal unit to the power grid in real time; Install current transformers, voltage transformers and power sensors at the incoming line position of the photovoltaic collection station to collect the current, voltage and power transmitted by the photovoltaic unit to the power grid in real time, and install light intensity sensors to monitor the light intensity in the area where the photovoltaic unit is located in real time, so as to provide a reference for the subsequent analysis of the operating status of the photovoltaic unit; A current transformer, a voltage transformer and a power sensor are installed at the energy storage inlet to collect the energy exchange between the energy storage system and the power grid, including the charging current, discharging current, charging power and discharging power, in real time, and a status monitoring device of the energy storage system is used to obtain information of the energy storage system, including the state of charge SOC and the state of health SOH; A current transformer, a voltage transformer and a power sensor are installed at the outlet of the start-up transformer to collect electrical quantity data including current, voltage, active power and reactive power transmitted by the solar thermal unit to the power grid in real time; The collected data is transmitted to a central control system, and the central control system performs pre-processing on the data including data verification, filtering, and format conversion; Through comprehensive judgment of the collected data, the three power grid operation combinations shown in Table 1 are obtained: Table 1 S2: Switch the operating mode state machine of the plateau isolated grid energy station system according to the determined operating mode of the power grid, and control each subsystem in each different operating mode using a control model that matches the operating mode.

[0028] like Figure 2 As shown, in step S2, the operation mode state machine of the plateau isolated grid energy station system is switched according to the determined operation mode of the power grid, specifically: The initial state of the grid is in the CSP & PV storage operation mode, that is, the CSP unit has power interaction with the grid, the PV unit generates electricity normally, the energy storage power station discharges according to grid demand, the diesel generator unit is in standby state, and the external grid performs power supplement. In this state, various subsystems work together to maintain stable operation of the grid and meet load demand; When the CSP unit is unable to supply power to the grid due to equipment failure or insufficient light, the PV unit still generates electricity under light conditions, and the discharge power of the energy storage power station is adjusted to ensure the stability of the total power supply of the grid. At the same time, the diesel generator set is in standby mode, and the external grid is used for power supplement; When the energy storage power station stops discharging due to power exhaustion or its own fault, the discharge power of the solar thermal unit is adjusted to ensure the stability of the total power supply of the power grid. The photovoltaic unit is still generating electricity under the light condition. At the same time, the diesel generator set is in standby state and the external network is used for power supplement; When the power grid encounters an emergency situation including a sudden and substantial increase in load, a sharp drop in power grid frequency or voltage, or a serious failure of any of the subsystems resulting in a serious shortage of power supply and a complete shutdown due to an accident, the diesel engine emergency start is triggered; When the system stops completely due to an accident and power supply needs to be restored, and the energy storage power station has the black start capability, the energy storage black start is triggered.

[0029] The following is a specific example of the detailed process of switching the above operation mode state machine: The initial state of the grid is set to the solar thermal & solar energy storage operation mode. In this mode, the subsystems work closely together to maintain the stable operation of the grid.

[0030] With its efficient photothermal conversion system, the solar thermal unit converts solar energy into thermal energy, and then converts thermal energy into electrical energy through a steam turbine-generator system, and realizes power interaction with the power grid. The unit is equipped with an advanced control system that can accurately adjust the steam flow and pressure according to the real-time power demand of the power grid to ensure the stability of the output power. For example, the operating parameters of the thermal collection system are monitored in real time by installing temperature sensors and pressure sensors in the collector field. The control system adjusts the angle of the concentrator and the working fluid flow of the collector based on these parameters to achieve the best photothermal conversion efficiency.

[0031] Photovoltaic units use photovoltaic arrays to directly convert solar energy into direct current, which is then converted into alternating current by an inverter and then connected to the grid. It uses maximum power point tracking (MPPT) technology to monitor the voltage, current, light intensity and other parameters of the photovoltaic array in real time, and uses algorithms to quickly calculate and adjust the working point of the inverter to ensure that the photovoltaic array always works near the maximum power point, thereby improving power generation efficiency. At the same time, in order to ensure the reliable operation of the photovoltaic unit, it is also equipped with a complete monitoring and protection system that can monitor the working status of the photovoltaic components in real time. When abnormal conditions such as overheating and leakage of components are detected, corresponding protection measures are taken in a timely manner, such as cutting off the circuit connection of the faulty component to avoid the expansion of the fault.

[0032] Energy storage power stations play a key regulatory role in the power grid, and perform charging and discharging operations according to the power fluctuations of the power grid. The power station uses an advanced battery management system (BMS) to monitor battery voltage, current, temperature, and state of charge (SOC) in real time. When the power grid is in excess, the BMS controls the energy storage battery to charge and store the excess electricity; when the power grid is insufficient, the BMS accurately controls the discharge power and discharge time of the battery according to the power grid demand to ensure stable power support for the power grid. For example, during the low power consumption period at night, if the power generation power of the solar thermal unit and the photovoltaic unit exceeds the load demand, the energy storage power station quickly starts the charging process; and during the peak power consumption period during the day, when the power generation power of the solar thermal unit and the photovoltaic unit cannot meet the load demand, the energy storage power station quickly discharges to make up for the power gap.

[0033] As a backup power source, the diesel generator set is always on standby. It has a quick start system that can complete the startup and reach the rated operating state in a short time after receiving the startup command. The control system of the diesel generator set monitors the operating parameters of the power grid in real time. Once an abnormal situation is detected in the power grid, such as frequency or voltage exceeding the normal range, and other power sources cannot meet the power demand, the diesel generator set is immediately started to provide emergency power support for the power grid. At the same time, the diesel generator set is also equipped with a complete protection system that can monitor the unit's oil temperature, oil pressure, speed and other parameters in real time during operation. When an abnormal situation occurs, shutdown protection measures are taken in time to ensure the safe operation of the unit.

[0034] The external network is connected to the energy station power grid through a dedicated transmission line to provide power supplement for the power grid. At the external network access point, high-precision power monitoring equipment is installed to monitor the power exchange between the external network and the energy station power grid in real time. When the internal power supply of the energy station cannot meet the load demand, the external network automatically adjusts the transmission power according to the actual power gap of the power grid to ensure the power balance of the energy station power grid. At the same time, in order to ensure the stability and reliability of external network access, multiple protection mechanisms are also set up, such as overcurrent protection, overvoltage protection, etc., to prevent external network failures from affecting the energy station power grid.

[0035] When the CSP unit is unable to supply power to the grid due to equipment failure or insufficient light, the system responds quickly. First, the operating status of the unit is monitored in real time through sensors installed at key parts of the CSP unit, such as temperature sensors, pressure sensors, vibration sensors, etc. Once an abnormality is detected, a fault alarm signal is immediately issued, and the cause of the fault is quickly located through the data analysis system. At this time, the photovoltaic unit continues to generate electricity under light conditions. The control system adjusts the discharge power of the energy storage power station according to the power demand of the power grid, combined with the real-time power generation power of the photovoltaic unit and the SOC state of the energy storage power station, to ensure the stability of the total power supply of the power grid. For example, when a CSP unit failure is detected, the control system quickly calculates the current power gap of the power grid, and then adjusts its discharge power according to the remaining power and discharge capacity of the energy storage power station to make up for the power loss of the CSP unit. At the same time, the control system also monitors the changes in the power generation power of the photovoltaic unit in real time. If the light intensity fluctuates, the discharge power of the energy storage power station is adjusted in time to ensure that the power of the power grid is always balanced.

[0036] When the energy storage power station stops discharging due to power exhaustion or its own fault, the system can also make adjustments quickly. The BMS of the energy storage power station monitors the SOC status and operating parameters of the battery in real time. When it detects that the battery power is too low or a fault occurs, it immediately sends an alarm signal and stops the battery charging and discharging operation. At this time, the control system adjusts the discharge power of the CSP unit according to the power demand of the power grid, combined with the real-time power generation power of the photovoltaic unit and the operating status of the CSP unit to ensure the stability of the total power supply of the power grid. For example, when the energy storage power station stops discharging due to power exhaustion, the control system quickly calculates the power gap of the current power grid, and then adjusts its output power according to the remaining power generation capacity and operating status of the CSP unit to make up for the power loss of the energy storage power station. At the same time, the control system also monitors the changes in the power generation power of the photovoltaic unit in real time. If the light intensity fluctuates, the output power of the CSP unit is adjusted in time to ensure that the power of the power grid is always balanced.

[0037] When the power grid encounters an emergency situation including a sudden and substantial increase in load, a sharp drop in power grid frequency or voltage, or a serious fault in any subsystem resulting in a serious shortage of power supply and a complete shutdown, the emergency start of the diesel engine is triggered. High-precision frequency and voltage monitoring equipment are installed at key nodes of the power grid, such as busbars, important load access points, etc., to monitor the frequency and voltage changes of the power grid in real time. At the same time, the control system of each subsystem monitors its own operating status in real time, and when an abnormal situation is detected, the fault information is immediately uploaded to the central control system. The central control system quickly determines whether to trigger the emergency start of the diesel engine based on the received fault information and the real-time operating parameters of the power grid. Once the start command is triggered, the diesel engine's start control system responds quickly, drives the diesel engine to operate through the starter motor, and quickly adjusts the diesel engine's fuel supply system and intake system, so that the diesel engine reaches the rated operating state in a short time and outputs power to the power grid. During the diesel engine start-up process, the control system also monitors the frequency and voltage changes of the power grid in real time, dynamically adjusts the output power of the diesel engine according to the power grid demand, and ensures the stable operation of the power grid.

[0038] When the system stops completely due to an accident and needs to restore power supply, and the energy storage power station has the ability to black start, the energy storage black start is triggered. After detecting the system power outage signal, the black start control system of the energy storage power station automatically starts the black start process. First, the energy storage battery inside the energy storage power station is used to provide initial power for the black start control system and key equipment, such as starting the battery management system, inverter and other equipment. Then, other equipment of the energy storage power station, such as charging devices and monitoring systems, are gradually started through the black start control system to put the energy storage power station into an operational state. After the energy storage power station is started, power is first supplied to important loads in the station, such as control systems, communication systems, lighting systems, etc., to establish a basic power supply environment. Then, according to the recovery needs of the power grid, the energy storage power station gradually outputs power to the power grid, while monitoring the voltage and frequency changes of the power grid to ensure the stable recovery of the power grid. After the voltage and frequency of the power grid are stable, other subsystems, such as solar thermal units and photovoltaic units, are gradually started in a predetermined order, and finally the full recovery of the entire energy station system is achieved.

[0039] The system identifies the operating mode, which provides a control basis for the control system on the one hand, and alarms the operating personnel on the other hand, making it easier for them to arrange production.

[0040] According to the control mode and control strategy of each subsystem, combined with the arrangement of the power grid operation mode, the control mode adopted by each subsystem under each operation mode is shown in Table 2 below.

[0041] Table 2 S3: Identify adjustable resources according to the determined operation mode of the power grid and the characteristics of the power source, and set the main frequency and voltage regulating power source under each operation mode.

[0042] According to the identification of the above operation mode, combined with the commissioning information and operation status of each power source point, the adjustable resources during the operation of the isolated grid are determined. Power sources are divided into three modes according to whether they can participate in frequency and voltage regulation: normal mode, transient process, and abnormal mode. Combining the above identification methods and the characteristics of the power source, solar thermal and energy storage can be used as the main frequency and voltage regulation power sources, so the identification results of adjustable resources are shown in Table 3 below.

[0043] Table 3 S4: According to the result of the identification of the adjustable resources, the control strategy of each of the subsystems serving as power supply points is set.

[0044] In this embodiment, step S4 is specifically as follows: Method 1: Solar thermal and solar energy storage operation Main frequency modulation equipment: photothermal; Main voltage regulating equipment: solar thermal; Photovoltaic operation mode: MPPT+droop; Diesel generator operation mode: droop; SVG operation mode: droop; Voltage source during low-breakthrough process: solar thermal + diesel generation; Method 2: Independent operation of energy storage When diesel generator power is included: Main frequency regulation equipment: energy storage; Main voltage regulating equipment: energy storage; Photovoltaic operation mode: pressure output + droop; Diesel generator operation mode: droop; SVG operation mode: droop; Voltage source during low-voltage break-through: energy storage + diesel generator; When diesel generator power generation is not included: Main frequency regulation equipment: energy storage; Main voltage regulating equipment: energy storage; Photovoltaic operation mode: pressure output + droop; Diesel generator operation mode: None; SVG operation mode: droop; Voltage source of low wear process: energy storage; Method 3: Solar thermal power independent load operation Main frequency modulation equipment: photothermal; Main voltage regulating equipment: solar thermal; Photovoltaic operation mode: MPPT+droop; Diesel generator operation mode: droop; SVG operation mode: droop; Voltage source during low-breakthrough process: solar thermal + diesel generation; Furthermore, the automatic topology identification method of the plateau isolated grid energy station of this embodiment further includes: Based on the identification of the adjustable resources, the subsystems that need to be controlled for real-time secondary frequency regulation and secondary voltage regulation are determined, and corresponding control instructions are issued. At the same time, when switching between the multiple operation modes, the switching process is ensured to be disturbance-free by real-time monitoring of the grid parameters and using a preset smooth switching algorithm, so as to ensure the stability of the grid; The preset smooth switching algorithm includes a switching algorithm based on power balance, a switching algorithm based on voltage phase synchronization, and a switching algorithm based on frequency tracking. The following is a brief description of these three algorithms: (1) Switching algorithm based on power balance: Working principle: Before and after the operation mode is switched, the algorithm continuously monitors the active power and reactive power output of each power source (solar thermal unit, photovoltaic unit, energy storage power station, diesel generator, etc.). By calculating the total power demand of the power grid in real time, the power adjustment amount of each power source is accurately controlled. For example, when switching from the solar thermal & photovoltaic storage operation mode to the energy storage independent operation mode, if the solar thermal unit stops running, the algorithm will quickly adjust the discharge power of the energy storage power station and the output power of the photovoltaic unit based on the previous power output of the solar thermal unit and the power generation capacity of the current photovoltaic unit and energy storage power station, to ensure that the total power of the power grid is always balanced at the moment of switching and afterwards, to avoid power grid fluctuations caused by sudden power changes.

[0045] Advantages: Effectively maintain the power stability of the power grid and ensure the normal operation of various loads. It is especially suitable for scenarios with large changes in power demand. It can respond and adjust power distribution in a timely manner, reduce the impact of mode switching on power supply, and improve the reliability of power supply of energy stations.

[0046] (2) Switching algorithm based on voltage phase synchronization: Working principle: When switching the operation mode, the algorithm focuses on the voltage phase of different power sources connected to the grid. By real-time monitoring and comparing the voltage phase information of each power source, when it is detected that the operation mode needs to be switched, the power source that is about to be put into or out of operation is controlled to keep its voltage phase consistent with the current voltage phase of the grid. For example, during the process of starting the diesel generator unit and connecting it to the grid, the phase of the diesel generator unit's output voltage is continuously adjusted to synchronize it with the grid voltage phase accurately, and then the diesel generator unit is connected to the grid to achieve smooth switching.

[0047] Advantages: It greatly reduces the impact current caused by voltage phase asynchrony, avoiding damage to power grid equipment. It increases the service life of power grid equipment, while ensuring the stability of power grid voltage during the switching process, providing reliable protection for loads with high voltage quality requirements.

[0048] (3) Switching algorithm based on frequency tracking: Working principle: With the frequency of the power grid as the core tracking object, the algorithm monitors the changes in the power grid frequency in real time during the switching of the operation mode. The control system of each power source automatically adjusts its own power generation frequency according to the fluctuation of the power grid frequency. For example, when the energy storage power station switches from the charging state to the discharging state to support the power grid, its control system closely tracks the power grid frequency and quickly adjusts the output frequency of the energy storage power station inverter to keep it consistent with the power grid frequency, ensuring the stability of the power grid frequency during the switching process.

[0049] Advantages: It effectively maintains the stability of the grid frequency and prevents equipment failure or abnormal operation caused by frequency fluctuations. For some frequency-sensitive equipment, such as industrial motors and precision instruments, the algorithm can ensure that they are not disturbed by frequency changes when switching operating modes and operate normally and stably, thereby improving the overall operation stability of the energy station and the reliability of the equipment.

[0050] These algorithms can be used individually or combined with each other according to actual conditions, providing solid technical support for the switching of isolated plateau energy stations between different operating modes, ensuring a smooth and disturbance-free switching process and maintaining stable operation of the power grid.

[0051] Second embodiment like Figure 3 As shown, this embodiment provides an automatic topology identification system for plateau isolated power station for executing the automatic topology identification method for plateau isolated power station in the first embodiment, characterized by comprising: The system operation mode identification module 1 is used to monitor the real-time operation status of key interconnection lines including the main transformer incoming line, photovoltaic collection station, energy storage incoming line, and standby transformer outgoing line, obtain the commissioning information of subsystems including solar thermal units, photovoltaic units, energy storage power stations, and diesel generators, and comprehensively judge the operation mode of the power grid; The operation mode state machine switching module 2 is used to switch the operation mode state machine of the plateau isolated grid energy station system according to the determined operation mode of the power grid, and to control each of the subsystems in each different operation mode using a control model matching the operation mode; The system adjustable resource identification module 3 is used to identify the adjustable resources according to the determined operation mode of the power grid and the characteristics of the power supply, and set the main frequency and voltage regulating power supply under each operation mode; The subsystem control strategy setting module 4 is used to set the control strategy of each of the subsystems serving as power supply points according to the result of the adjustable resource identification.

[0052] A computer-readable storage medium stores computer code. When the computer code is executed, the above method is executed. A person skilled 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 related hardware through a program. The program can be stored in a computer-readable storage medium. The storage medium can include: a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, etc.

[0053] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

[0054] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0055] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. An automatic topology identification method for plateau isolated grid energy stations, characterized in that: The following steps are involved: S1: By monitoring the real-time operating status of key interconnection lines including the main transformer incoming line, photovoltaic collection station, energy storage incoming line, and standby transformer outgoing line, the operation information of subsystems including solar thermal units, photovoltaic units, energy storage power stations, and diesel generators is obtained, and the operation mode of the power grid is comprehensively judged; S2: switching the operation mode state machine of the plateau isolated grid energy station system according to the determined operation mode of the power grid, and controlling each of the subsystems in each different operation mode using a control model matching the operation mode; S3: Identify adjustable resources according to the determined operation mode of the power grid and the characteristics of the power source, and set the main frequency and voltage regulating power source under each operation mode; S4: According to the result of the identification of the adjustable resources, the control strategy of each of the subsystems serving as power supply points is set.

2. The automatic topology identification method of plateau isolated grid energy station according to claim 1 is characterized in that: In step S1, by monitoring the real-time operating status of key interconnection lines including the main transformer incoming line, photovoltaic collection station, energy storage incoming line, and standby transformer outgoing line, the operation information of subsystems including solar thermal units, photovoltaic units, energy storage power stations, and diesel generators is obtained, and the operation mode of the power grid is comprehensively judged, specifically: A current transformer, a voltage transformer and a power sensor are installed at the inlet of the main transformer to collect electrical quantity data including three-phase current, voltage, active power and reactive power transmitted by the solar thermal unit to the power grid in real time; Install current transformers, voltage transformers and power sensors at the incoming line position of the photovoltaic collection station to collect the current, voltage and power transmitted by the photovoltaic unit to the power grid in real time, and install light intensity sensors to monitor the light intensity in the area where the photovoltaic unit is located in real time, so as to provide a reference for the subsequent analysis of the operating status of the photovoltaic unit; A current transformer, a voltage transformer and a power sensor are installed at the energy storage inlet to collect the energy exchange between the energy storage system and the power grid, including the charging current, discharging current, charging power and discharging power, in real time, and a status monitoring device of the energy storage system is used to obtain information of the energy storage system, including the state of charge SOC and the state of health SOH; A current transformer, a voltage transformer and a power sensor are installed at the outlet of the start-up transformer to collect electrical quantity data including current, voltage, active power and reactive power transmitted by the solar thermal unit to the power grid in real time; The collected data is transmitted to a central control system, and the central control system performs pre-processing on the data including data verification, filtering, and format conversion; Through comprehensive judgment of the collected data, the following three power grid operation combinations are obtained: Mode 1: Solar thermal & solar energy storage operation, the power supply points are: solar thermal + photovoltaic + energy storage + diesel generation / external grid supplement; Method 2: Energy storage operates independently, and the power supply points are: energy storage + photovoltaic + diesel generation / external grid energy supplement; Method three: Solar thermal power operates independently with load, and the power supply points are: solar thermal power + photovoltaic power + diesel power generation.

3. The automatic topology identification method of plateau isolated grid energy station according to claim 1 is characterized in that: In step S2, the operation mode state machine of the plateau isolated grid energy station system is switched according to the determined operation mode of the power grid, specifically: The initial state of the grid is in the CSP & PV storage operation mode, that is, the CSP unit has power interaction with the grid, the PV unit generates electricity normally, the energy storage power station discharges according to grid demand, the diesel generator unit is in standby state, and the external grid performs power supplement. In this state, various subsystems work together to maintain stable operation of the grid and meet load demand; When the CSP unit is unable to supply power to the grid due to equipment failure or insufficient light, the PV unit still generates electricity under light conditions, and the discharge power of the energy storage power station is adjusted to ensure the stability of the total power supply of the grid. At the same time, the diesel generator set is in standby mode, and the external grid is used for power supplement; When the energy storage power station stops discharging due to power exhaustion or its own fault, the discharge power of the solar thermal unit is adjusted to ensure the stability of the total power supply of the power grid. The photovoltaic unit is still generating electricity under the light condition. At the same time, the diesel generator set is in standby state and the external network is used for power supplement; When the power grid encounters an emergency situation including a sudden and substantial increase in load, a sharp drop in power grid frequency or voltage, or a serious failure of any of the subsystems resulting in a serious shortage of power supply and a complete shutdown due to an accident, the diesel engine emergency start is triggered; When the system stops completely due to an accident and power supply needs to be restored, and the energy storage power station has the black start capability, the energy storage black start is triggered.

4. The automatic topology identification method of plateau isolated grid energy station according to claim 1 is characterized in that: In step S2, each of the subsystems is controlled in each of the different operation modes using a control model that matches the operation mode, specifically: Method 1: Solar thermal and solar energy storage operation Solar thermal systems: frequency and voltage droop modes; Energy storage system: grid-connected mode; Asynchronous interconnection: active response mode; Photovoltaic system: constant power mode; SVG system: AVC mode; Diesel generator system: mains mode; Method 2: Independent operation of energy storage Solar thermal system: shutdown; Energy storage system: off-grid mode; Asynchronous interconnection: active response mode; Photovoltaic system: constant power mode; SVG system: AVC mode; Diesel generator system: mains mode; Method 3: Solar thermal power independent load operation Solar thermal system: single machine frequency modulation mode; Energy storage system: shutdown; Asynchronous interconnection: outage; Photovoltaic system: constant power mode; SVG system: AVC mode; Diesel generator system: Mains mode.

5. The automatic topology identification method of plateau isolated grid energy station according to claim 1 is characterized in that: In step S3, according to the determined operation mode of the power grid and the characteristics of the power supply, the main frequency-regulated and voltage-regulated power supply in each operation mode is set, specifically: Method 1: CSP & PV-storage operation, with CSP as the main frequency and voltage regulator; Method 2: Energy storage operates independently, and energy storage serves as the main frequency and voltage regulator; Method three: Solar thermal operates independently with load, and solar thermal is used as the main force for frequency and voltage regulation.

6. The automatic topology identification method of plateau isolated grid energy station according to claim 1 is characterized in that: In step S4, according to the result of the adjustable resource identification, the control strategy of each subsystem as a power source point is set, specifically: Method 1: Solar thermal and solar energy storage operation Main frequency modulation equipment: photothermal; Main voltage regulating equipment: solar thermal; Photovoltaic operation mode: MPPT+droop; Diesel generator operation mode: droop; SVG operation mode: droop; Voltage source during low-breakthrough process: solar thermal + diesel generation; Method 2: Independent operation of energy storage When diesel generator power is included: Main frequency regulation equipment: energy storage; Main voltage regulating equipment: energy storage; Photovoltaic operation mode: pressure output + droop; Diesel generator operation mode: droop; SVG operation mode: droop; Voltage source during low-voltage break-through: energy storage + diesel generator; When diesel generator power generation is not included: Main frequency regulation equipment: energy storage; Main voltage regulating equipment: energy storage; Photovoltaic operation mode: pressure output + droop; Diesel generator operation mode: None; SVG operation mode: droop; Voltage source of low wear process: energy storage; Method 3: Solar thermal power independent load operation Main frequency modulation equipment: photothermal; Main voltage regulating equipment: solar thermal; Photovoltaic operation mode: MPPT+droop; Diesel generator operation mode: droop; SVG operation mode: droop; Voltage source during the low-breakthrough process: solar thermal + diesel generation.

7. The automatic topology identification method of plateau isolated grid energy station according to claim 1 is characterized in that: Also includes: Based on the identification of the adjustable resources, the subsystems that need to be controlled for real-time secondary frequency regulation and secondary voltage regulation are determined, and corresponding control instructions are issued. At the same time, when switching between the multiple operation modes, the switching process is ensured to be disturbance-free by real-time monitoring of the grid parameters and using a preset smooth switching algorithm, so as to ensure the stability of the grid; The preset smooth switching algorithm includes a switching algorithm based on power balance, a switching algorithm based on voltage phase synchronization, and a switching algorithm based on frequency tracking.

8. An automatic topology identification system for plateau isolated power grid energy stations for executing the automatic topology identification method for plateau isolated power grid energy stations as described in any one of claims 1 to 7, characterized in that: include: The system operation mode identification module is used to monitor the real-time operation status of key interconnection lines including the main transformer incoming line, photovoltaic collection station, energy storage incoming line, and standby transformer outgoing line, obtain the commissioning information of subsystems including solar thermal units, photovoltaic units, energy storage power stations, and diesel generators, and comprehensively determine the operation mode of the power grid; An operation mode state machine switching module is used to switch the operation mode state machine of the plateau isolated grid energy station system according to the determined operation mode of the power grid, and to control each of the subsystems in each different operation mode using a control model matching the operation mode; A system adjustable resource identification module, used to identify adjustable resources according to the determined operation mode of the power grid and the characteristics of the power supply, and set the main frequency and voltage regulating power supply under each operation mode; The subsystem control strategy setting module is used to set the control strategy of each of the subsystems serving as power supply points according to the result of the adjustable resource identification.

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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