New energy participated microgrid black start control method and device, medium and product

Abstract

The invention discloses a new energy participated microgrid black start control method and device, a medium and a product, and relates to the field of power supply. After it is detected that the micro-grid system breaks down and enters the all-black state, whether the black start requirement is met or not is judged firstly; if yes, all loads in the micro-grid system are cut off to be in a no-load state; in a no-load state, each black-start power supply in the micro-grid system respectively adopts a constant-voltage / constant-frequency control mode to carry out on-load starting; after on-load starting and stable operation are completed, synchronous parallel networking of the black-start power supply is carried out; after stable operation, a non-black-start power supply in the micro-grid system is connected step by step, and residual loads are put into step by step; in the process, the operation state of the micro-grid is optimized in real time, all non-black-start power supplies are connected and all loads are input on the premise that the micro-grid system operates stably, and therefore the black-start process of the micro-grid can be smoothly completed with the participation of high-proportion new energy, and it is guaranteed that the system operates safely, stably and efficiently.

Description

Technical Field

[0001] This application relates to the field of power supply technology, and in particular to a black start control method, device, medium and product for microgrids with new energy participation. Background Technology

[0002] As renewable energy continues to account for an increasing proportion of the power system, the safe operation and stable control of microgrids have become critical challenges that urgently need to be addressed. Distributed renewable energy sources such as wind power and photovoltaics exhibit significant volatility and intermittency, posing numerous challenges to the recovery process of microgrids after faults, especially during black start scenarios.

[0003] When a microgrid enters a complete blackout state due to internal or external faults, it not only causes severe economic losses but also brings great inconvenience to daily life. To minimize the adverse effects of microgrid outages, developing a safe, fast, and reliable microgrid black-start recovery scheme is crucial. An effective black-start scheme should consider various factors, including the complexity of the power system, the characteristics of renewable energy sources, and changes in load demand. An optimized black-start scheme can significantly shorten outage time, reduce economic losses, and restore normal production and daily life. Conversely, a lack of an effective black-start strategy can not only prolong outage time but may also lead to secondary damage to the power system, further exacerbating losses and inconvenience. Foreign scholars have conducted in-depth research on microgrid black-start. The basic principle is to select a black-start power source with voltage and frequency regulation capabilities, consider the urgency of load power supply, and complete the microgrid black-start recovery process by optimizing the power output of the black-start recovery grid and other power sources.

[0004] However, there is limited research on the high proportion of distributed renewable energy sources involved in microgrid black-start recovery. Most studies use traditional fuel-fired generators or energy storage devices as black-start power sources, but in microgrids with a high proportion of distributed renewable energy sources, using a single traditional fuel-fired generator as the black-start power source is clearly unsuitable; if a single energy storage device is used as the black-start power source, insufficient rated capacity and output power may lead to system voltage and frequency oscillations. Summary of the Invention

[0005] The purpose of this application is to provide a black-start control method, device, medium, and product for microgrids with renewable energy participation, which can enable the microgrid to successfully complete the black-start process and ensure the safe, stable, and efficient operation of the system in microgrids with a high proportion of renewable energy participation.

[0006] To achieve the above objectives, this application provides the following solution.

[0007] Firstly, this application provides a black-start control method for microgrids with renewable energy participation, including: After a fault is detected in the microgrid system and it enters a completely dark state, it is determined whether the black start requirements are met; the microgrid system includes distributed new energy systems, fuel-fired generators, energy storage devices, and local loads; If the black start requirement is met, disconnect all loads in the microgrid system to put it into an unloaded state. Under no-load conditions, each black-start power source in the microgrid system adopts constant voltage / constant frequency control mode for load starting; the black-start power source includes fuel unit and energy storage device. After each black starter power supply completes its load start-up and stabilizes, it is then connected in parallel to form a network. After the black-start power source completes synchronous parallel networking and stable operation, the non-black-start power source is gradually connected to the microgrid system and gradually put into the remaining load in the microgrid system; the non-black-start power source is a distributed new energy system. During the process of connecting non-black start power sources and putting loads into operation, the microgrid's operating status is optimized in real time. Under the premise of stable operation of the microgrid system, all non-black start power sources are connected and all loads are put into operation.

[0008] Optionally, the black boot requirement is determined to be met when all of the following conditions are met: The grid connection / off-grid control switch of the overall microgrid system is in the open state; All selected black start power supplies can start and operate normally and have sufficient capacity to drive the load. The voltage and frequency on the AC bus of the microgrid are both 0; All power supplies and load switches are in the off state.

[0009] Optionally, each black-start power supply in the microgrid system adopts a constant voltage / constant frequency control mode for load starting, specifically including: The constant voltage / constant frequency control strategy of each black start power supply uses a 50Hz frequency and a 400V line voltage amplitude and initial phase as inputs, so that each black start power supply can start automatically with the corresponding load and operate under constant voltage and frequency.

[0010] Optionally, the synchronous parallel networking of the black-start power supply specifically includes: Using the fuel-fired generator set as the main reference power source and the energy storage device as the non-main reference power source, pre-synchronization between the non-main reference power source and the main reference power source is achieved. After the pre-synchronization of the fuel unit and the energy storage device is achieved and both are operating stably, the fuel unit and the energy storage device are connected in parallel. At the moment of parallel connection, the energy storage device is switched from constant voltage / constant frequency control mode to constant power control mode.

[0011] Optionally, the non-black-start power source gradually integrated into the microgrid system specifically includes: Start the non-black start power supply in constant power control mode to make it output the set power value. It is integrated into the network with reference to the operating information of the main reference power source.

[0012] Optionally, during the connection of the non-black start power supply, the following power constraints must be met: ; in Power sources that have completed startup within the microgrid system Maximum output power, total The power supply has completed startup; The first AC bus of the microgrid system No-load loss, total indivual; The first generation generated during the startup of a non-black-start power supply in a microgrid system Each impact power, total indivual.

[0013] Optionally, the following constraints must be met during the load assignment process: ; ; ; ; in For the first in a microgrid system A load capacity, total indivual; For the first in a microgrid system Each rated capacity, total indivual; and These are the AC bus voltages of the microgrid system. Upper and lower limits of amplitude; Frequency deviation within the microgrid system; and Power sources within the microgrid system Output active power value The upper and lower limits; Indicates power supply The quantity.

[0014] Secondly, this application provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the encrypted malicious traffic detection method of the industrial control system.

[0015] Thirdly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the encrypted malicious traffic detection method of the industrial control system.

[0016] Fourthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements an encrypted malicious traffic detection method for the industrial control system.

[0017] According to the specific embodiments provided in this application, the following technical effects are disclosed: This application provides a black-start control method, equipment, medium, and product for microgrids with renewable energy participation. While meeting the reasonable fluctuation requirements for normal operation of the microgrid system, it considers the urgency of load power supply and optimizes the black-start sequence using different distributed power sources to quickly restore load power supply. Simultaneously, it effectively mitigates the current and power surges generated during the black-start power source startup, synchronous paralleling, other distributed power source startup and integration, and load switching, avoiding significant fluctuations in system voltage and frequency. From a global perspective, it optimizes the microgrid system's generating capacity, reduces the proportion of traditional fuel-fired units, increases the proportion of renewable energy within the system, and enables the microgrid to successfully complete the black-start process while ensuring safe, stable, and efficient system operation. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart illustrating a microgrid black-start control method involving new energy sources, as described in this application. Figure 2 This is a microgrid system topology diagram provided in the embodiments of this application; Figure 3 This is a schematic diagram of the pre-synchronization structure used in the method of this application; Figure 4 This is a schematic diagram of control mode switching based on power compensation; Figure 5 This is a block diagram of a constant power control strategy; Figure 6 Block diagram of constant voltage / constant frequency control strategy; Figure 7 A schematic diagram illustrating the active power variation of a micro-source as an example of a microgrid system; Figure 8 A schematic diagram illustrating the change in active power of a load as an example of a microgrid system; Figure 9 A schematic diagram illustrating the variation of the effective value of the AC bus voltage in a microgrid system, as an example. Figure 10 This is a schematic diagram illustrating the system frequency variation as an example of a microgrid system. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] The purpose of this application is to propose a black-start control method, device, medium, and product for microgrids with renewable energy participation, aiming to smoothly complete the black-start process of microgrids in microgrid systems with a high proportion of distributed renewable energy, quickly restore load power supply, and ensure the stable operation of the microgrid system.

[0022] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] In one exemplary embodiment, this application provides a black-start control method for microgrids with renewable energy participation, such as... Figure 1 As shown, it includes the following steps 1 to 6.

[0024] Step 1: After detecting a fault in the microgrid system and entering a completely dark state, determine whether the black start requirements are met.

[0025] The method described in this application applies to microgrid systems with a high proportion of distributed renewable energy sources. The configured microgrid system should include at least a distributed renewable energy system, a fuel-fired generator unit, energy storage devices, and local loads. The distributed renewable energy system can be a photovoltaic power generation system, a wind power generation system, a hydropower generation system, a biomass and biogas power generation system, a geothermal and ocean energy power generation system, etc. The fuel-fired generator unit can be a high-speed / medium-speed / heavy oil / biodiesel generator set, a micro gas turbine (oil-based), an aero-derived gas turbine (light diesel), etc. The energy storage devices include electrochemical energy storage devices and mechanical / electromagnetic energy storage devices, etc.

[0026] Considering the characteristics and dynamic performance of various power sources, this application selects fuel-fired generators and energy storage devices as black-start power sources for microgrids. The fuel-fired generators serve as the primary reference power source, the energy storage devices as a non-primary reference power source, and the distributed renewable energy system as a non-black-start power source. All three are referred to as micro-power sources within the microgrid system. This application's black-start method, which combines fuel-fired generators and energy storage devices, is the black-start strategy required for microgrids with a high proportion of distributed renewable energy. It leverages different distributed power sources, optimizes the black-start sequence based on the urgency of load power supply, rapidly restores load power supply within the microgrid, optimizes system capacity, increases the proportion of distributed renewable energy within the microgrid system, and enables the system to operate with better stability.

[0027] The method described in this application is typically deployed at the microgrid control center. After a fault is detected in the microgrid system, which enters a completely black state, the microgrid control center first analyzes the system to ensure that the black start requirements are met before initiating the microgrid black start scheme. Specifically, the microgrid is considered to meet the black start requirements when all of the following conditions are met: 1) The grid connection / off-grid control switches of the entire microgrid system are in the open state, because microgrid black start needs to be performed under islanded conditions; 2) The selected black start power supplies can all start and operate normally and have sufficient capacity to drive the load; 3) The voltage and frequency on the microgrid AC bus are both 0; 4) All power supplies and load switches are in the open state.

[0028] Step 2: If the black start requirement is met, disconnect all loads in the microgrid system to put it into an unloaded state.

[0029] To avoid power failure due to excessive load during the initial black start of the microgrid, which could lead to black start failure, all loads in the system should be disconnected so that the microgrid black start power supply starts under no-load conditions.

[0030] Step 3: Under no-load conditions, each black-start power supply in the microgrid system is started under load using constant voltage / constant frequency control mode.

[0031] The black start power supply includes a fuel-fired generator set and an energy storage device. During startup, the constant voltage / constant frequency (V / f) control strategy of each black start power supply uses a 50Hz frequency and a voltage amplitude and initial phase of a 400V line voltage as input, enabling each black start power supply to automatically start with its corresponding load and operate at a constant voltage and frequency.

[0032] The following is based on Figure 2 The microgrid system shown is used as an example for detailed explanation.

[0033] Figure 2The microgrid system shown consists of a photovoltaic (PV) power generation system (distributed renewable energy system), a diesel generator (fuel-fired unit), a grid-connected energy storage system (energy storage device), and local loads. The microgrid control center controls the switching of micro-power sources and loads by controlling the opening and closing of circuit breakers (switches S1-S8). There are four local loads within the microgrid. Loads 2 and 4 are critical loads, connected to the diesel generator and the grid-connected energy storage system respectively, ensuring priority power restoration for them. Loads 1 and 3 are general loads, connected to the AC bus and the PV array respectively. The microgrid control center controls the connection of loads and power sources through control switches and controls the output power of the power sources through corresponding controllers. In this example microgrid system, the diesel generator has a rated power of 60kW, the energy storage system has a rated capacity of 70kW, and the PV system has a rated capacity of 60kW; therefore, renewable energy accounts for a relatively high proportion in this example.

[0034] Under no-load conditions, the microgrid's black-start power supply initiates the establishment of its subsystems. Upon receiving the start-up signal from the microgrid control center, the diesel generator and the grid-connected energy storage system each automatically start with their respective loads using constant voltage / constant frequency control, establishing the voltage and frequency necessary for stable operation of their subsystems. In this example, the diesel generator is connected to a 20kW load 2 on one line, and the grid-connected energy storage system is connected to a 30kW load 4 on another line. These two lines are independent, each forming a subsystem. During startup, a 50Hz frequency, 400V line voltage amplitude, and initial phase are used as inputs to the strategy, allowing both subsystems to operate at constant voltage and frequency under constant voltage / constant frequency control, automatically outputting the corresponding active power according to load requirements. This step ensures that critical loads are prioritized for power supply by the diesel generator and the grid-connected energy storage system, minimizing the inconvenience caused by power outages of critical loads.

[0035] The system consists of two subsystems: one composed of a diesel generator and load 2, and the other composed of a grid-connected energy storage system and load 4. The two subsystems operate independently until they are connected in parallel. Stable voltage and frequency are maintained by a constant voltage / constant frequency control strategy. The control strategy for the diesel generator and grid-connected energy storage system uses a 50Hz frequency, a 400V line voltage amplitude, and an initial phase as input to ensure both subsystems operate at constant voltage and frequency. Because the two subsystems will be connected in parallel later, their voltage amplitude, phase, and frequency must remain consistent; therefore, a constant voltage / constant frequency control method, also known as a control mode or control strategy, is employed.

[0036] Step 4: After each black starter power supply completes its load start-up and stable operation, the black starters power supplies are connected in parallel and networked simultaneously.

[0037] The method for synchronous parallel networking of black-start power supplies includes the following steps 4.1 to 4.2.

[0038] Step 4.1: Using the fuel cell generator as the primary reference power source and the energy storage device as the secondary reference power source, pre-synchronization between the secondary and primary reference power sources is achieved.

[0039] When two black-start power supplies are connected in parallel, the voltage amplitude, phase, and frequency must be kept consistent. To ensure smooth parallel operation, pre-synchronization of the two black-start power supplies is necessary. Before parallel connection, the voltage and frequency of the power supply to be synchronized (not the main reference power supply) are provided by its own constant voltage / constant frequency control method. During parallel connection, the "voltage reference value selection" switches to a reference value provided in real time by the main reference power supply, thus achieving synchronized operation with the main reference power supply. Then, after the two black-start power supplies have stabilized, the parallel connection can be performed, significantly reducing the impact of the two subsystems operating in parallel.

[0040] The pre-synchronization structure used in this application is as follows: Figure 3 As shown. The main reference power supply is converted from DC to AC by an inverter, and then passed through an LCL filter (…). (For filter parameters) Generate the three-phase voltage of the main reference power supply After dq transformation, it is converted into d-axis voltage. With q-axis voltage . and The reference voltage for the dq axis of the power supply to be synchronized is the initial input value for the constant voltage / constant frequency control mode. Before the main reference power supply and the power supply to be synchronized are connected in parallel, the input reference value of the diesel generator and the grid-connected energy storage system is provided by the reference signal generated by their own constant voltage / constant frequency control. This reference signal refers to the PWM wave inverter control signal generated by the constant voltage / constant frequency control strategy with a voltage amplitude and initial phase input at a frequency of 50Hz and a line voltage of 400V in the initial state. Just before the parallel connection is required, the input reference value of the grid-connected energy storage system (… and ) is converted to be supplied in real time by the main reference power source (diesel generator) and The two gradually achieve synchronized operation. After the above pre-synchronization steps, the "voltage reference value selection" is... and Turn to and , and The voltage reference value is generated in real time by the main reference power source and supplied to the power source to be synchronized. After the voltage reference value of the power source to be synchronized is provided by the main reference source, the voltage amplitude, phase and frequency of the two are synchronized, thus achieving pre-synchronization between the two.

[0041] for Figure 2The microgrid system shown, after the microgrid black-start power supply completes load start-up and stable operation, uses the diesel generator's operating status information (including voltage amplitude, phase, and frequency) as a reference to pre-synchronize the operating status information of the small independent power system (subsystem) established by the grid-type energy storage system with the diesel generator. After... Figure 3 After the pre-synchronization step shown, the pre-synchronization operation of the power source to be synchronized (grid-type energy storage system) and the main reference power source (diesel generator) is realized, which greatly reduces the impact of the subsequent switch closing and parallel operation in step 4.2 and improves the success rate of parallel connection.

[0042] Step 4.2: After the pre-synchronization of the fuel unit and the energy storage device is achieved and both are operating stably, the fuel unit and the energy storage device are connected in parallel. At the moment of parallel connection, the energy storage device is switched from constant voltage / constant frequency control mode to constant power control mode.

[0043] When two black start power supplies are connected in parallel, it is essential to ensure that their voltage amplitude, phase, and frequency remain consistent. The pre-synchronization step in this application effectively enables the two black start power supplies to operate synchronously, ensuring that their voltage amplitude, phase, and frequency remain consistent, thus reducing the impact caused by parallel operation. After the fuel unit and energy storage device are operating stably, their parallel switch is closed to achieve parallel operation of the black start power supplies, effectively mitigating the transient impact caused by parallel operation of black start power supplies.

[0044] for Figure 2 In the microgrid system example shown, closing the circuit breaker refers to closing the parallel switch between subsystem 1 (composed of a diesel generator and load 2) and subsystem 2 (composed of a grid-connected energy storage system and load 4). Both the diesel generator and the grid-connected energy storage system are black-start power sources, and they need to be connected in parallel during the black-start process. After the pre-synchronization step, the voltage amplitude, phase, and frequency of the two systems reach the conditions for synchronized operation. At this time, the switch is not yet closed, and the two black-start power sources are not physically connected. Therefore, after the switch is closed, the two systems achieve parallel operation.

[0045] It is important to note that at the instant the black-start power supply is connected in parallel, the control mode of the grid-type energy storage system also needs to be switched. At the instant the black-start power supply is connected in parallel, the control mode of the grid-type energy storage system switches from constant voltage / constant frequency (V / f) control to constant power (PQ) control, using the voltage and frequency of the main reference power supply as a reference for stable operation and outputting constant power. This application employs a mode switching method based on power compensation, such as... Figure 4 As shown.

[0046] Figure 4The mode switching strategy of a grid-based energy storage system is illustrated, achieved by switching between two different controllers (constant voltage / constant frequency control and constant power control). When a non-primary reference power source with black-start capability is connected in parallel to the primary reference power source, it is necessary to switch from constant voltage / constant frequency control to constant power control, using the voltage and frequency provided by the primary reference power source as a reference to output constant active power. However, during mode switching, mismatch in the states of the two controllers can lead to oscillations or even switching failures. Therefore, a mode switching method based on power compensation is used. Figure 4 As shown, K1 is the control switch for the constant voltage / constant frequency controller, and K2 is the control switch for the constant power controller. When K1 is closed and K2 is open, the power memory module calculates the power for reference, and the constant power controller runs simultaneously to ensure consistency of the controller state. When K1 is open and K2 is closed, the power memory module calculates and stores the power output power before the switch, providing an active power reference for the constant power control after the switch, ensuring that the power output power and current remain unchanged before and after the mode switch, and that the controller state remains consistent before and after the mode switch.

[0047] Specifically, before the black-start power supply is connected in parallel, based on the collected voltage... and current Based on this information, the real-time power output value of the non-primary reference power source (grid-based energy storage system) is calculated. At this time, switch K1 is closed and K2 is off, and the grid-type energy storage inverter operates in constant voltage / constant frequency control mode. When the black-start power supply is connected in parallel, switch K1 is off and K2 is closed, the control mode of the grid-type energy storage inverter switches to constant power control mode, and the output power at the last moment before the switch is recorded. As a reference power for constant power control mode after mode switching This ensures consistency in state before and after switching between the two control modes, guaranteeing smooth parallel connection of the black-start power supply. The block diagram of the constant power control strategy adopted in this application is shown below. Figure 5 As shown, the block diagram of the constant voltage / constant frequency control strategy is as follows: Figure 6 As shown.

[0048] See Figure 5 In constant power (PQ) control, the d-axis is in the same direction as the voltage vector, and the voltage component on the q-axis is 0. At this time, the active power and current components on the d-axis are... Related, reactive power and current components on the q-axis Relatedly, the current reference value can be calculated from the power reference value and the voltage component on the dq axis: (1) (2) In the formula This is the reference value for the d-axis current. This is the reference value for the q-axis current. This is a reference value for active power. This is a reference value for reactive power. Let be the voltage component along the d-axis.

[0049] Constant power control uses a current inner loop controller to set the current reference value. With the components of the current on the dq axis The difference is calculated, and the output voltage control signal is controlled by a PI controller. Its inner current control equation is: (3) (4) In the formula For PI control parameters, Angular frequency, For filtering inductors, This is the reference value for the dq-axis voltage of the inner current loop. The three-phase voltage reference value is output after inverse Parker transformation. .

[0050] See Figure 6 Constant voltage / constant frequency control is used to provide voltage and frequency references for the system. Its inner current control principle is the same as that of constant power control, while the outer loop adopts a voltage control outer loop structure. The voltage outer loop control equation is as follows: (5) (6) In the formula This is the reference value for the dq-axis current. For PI control parameters, This is the reference value for the dq axis voltage. For the dq axis voltage components, Angular frequency, The filter capacitor coefficient is denoted as .

[0051] Step 5: After the black-start power supply completes synchronous parallel networking and stable operation, the non-black-start power supply in the microgrid system is gradually connected and gradually put into the remaining load in the microgrid system.

[0052] This application is designed to reduce the proportion of traditional fuel-fired power units (diesel generators) and increase the proportion of renewable energy. The overall goal is to ensure effective, rapid, and stable operation of the system during black start in a microgrid with a high proportion of renewable energy participation. Therefore, after the black start power source completes synchronous parallel grid connection and stable operation, non-black start power sources (such as photovoltaic power generation systems) are started in constant power control mode to output a set power value. The photovoltaic (PV) power generation system is connected to the grid with reference to the operating information of the primary reference power source (e.g., a diesel generator). Because the PV system operates under constant power control, it can only output a set amount of active power. Its voltage and frequency need to be supported by the primary reference power source. Therefore, its grid connection requires reference to the voltage amplitude, phase, and frequency of the primary reference power source. A phase-locked loop (PLL) is used to lock the current voltage phase of the primary reference power source, and the voltage amplitude and frequency of the primary reference power source are used to adjust the constant power control strategy parameters, mitigating the significant impact of grid connection during PV system integration.

[0053] During the process of integrating the non-black start power supply, the following power constraints must be met: (7) in Power sources that have completed startup within the microgrid system Maximum output power, total The power supply has completed startup; The first AC bus of the microgrid system No-load loss, total indivual; The first generation generated during the startup of a non-black-start power supply in a microgrid system Each impact power, total When the maximum output power of the power source in the grid, that is, the rated capacity, is large enough, it can reduce the impact on the system when the non-black start power source starts. With this power constraint condition (7), the capacity boundary that the non-black start power source in the grid can start safely can be measured. After the black start power source is connected to the grid, the rated power generation capacity inside the system increases, which can effectively reduce the power impact caused by the connection of the non-black start power source and maintain the stability of the system frequency and voltage.

[0054] During the gradual integration of non-black-start power sources, it is also necessary to gradually increase the load within the microgrid system. Based on the microgrid system's operating status, partial loads should be added gradually. During load addition, the frequency and voltage of the microgrid system should be kept within a reasonable fluctuation range. Therefore, the following constraints should be met when adding loads: (8) (9) (10) (11) in For the first in a microgrid system A load capacity, total indivual; For the first in a microgrid system Each rated capacity, total indivual; and These are the AC bus voltages of the microgrid system. Upper and lower limits of amplitude; Frequency deviation within the microgrid system; and Power sources within the microgrid system Output active power value The upper and lower limits; Indicates power supply The quantity.

[0055] Step 6: During the process of connecting non-black start power sources and putting loads into operation, optimize the microgrid's operating status in real time, and connect all non-black start power sources and put all loads into operation under the premise of stable operation of the microgrid system.

[0056] During the process of connecting non-black-start power sources (photovoltaic power generation systems) or adding loads, instability in the entire microgrid system may occur due to unreasonable load input or output power settings of the non-black-start power sources. In this case, it is necessary to appropriately disconnect some loads or adjust the output power of each microgrid power source to allow the already stable power sources to provide power support first. Once the non-black-start power sources gradually stabilize, the output power of each power source can be adjusted again to improve the absorption of distributed renewable energy sources such as photovoltaic power generation systems. Since it is uncertain whether the instability of the system during black start is caused by the added load, the connection of non-black-start power sources, or other factors, it is necessary for the microgrid control center to observe and analyze the situation. By adjusting the output of the generator sets and disconnecting loads in real time, the entire system can be stabilized before the generator output is adjusted again and loads are added to ensure a smooth black start of the system.

[0057] This application performs real-time optimization of the microgrid system during the non-black start power supply connection and load connection process. By adjusting the output power value of each micro power source in the microgrid system and switching some loads, it maintains the stability of system voltage and frequency, reduces the output of diesel generator sets, and improves the absorption capacity of distributed new energy sources such as photovoltaic power generation systems.

[0058] This application proposes a black-start control method for microgrids with renewable energy participation. While meeting the reasonable fluctuation requirements for normal operation of the microgrid system, it considers the urgency of load power supply and optimizes the black-start sequence using different distributed power sources to quickly restore load power supply. Simultaneously, this method effectively mitigates current and power surges during the black-start power source startup, synchronous paralleling, integration of other distributed power sources, and load switching, avoiding significant fluctuations in system voltage and frequency. Furthermore, this method optimizes the microgrid system's generation capacity from a global perspective, reduces the proportion of traditional fuel-fired units, increases the proportion of renewable energy within the system, and enables the microgrid to successfully complete the black-start process while ensuring safe, stable, and efficient system operation.

[0059] against Figure 2 The microgrid system in the example is simulated during its black start process, including the output power control of each micro-source and load switching. The changes in active power of the micro-sources are obtained as follows: Figure 7 As shown, the change in active power of the load is as follows: Figure 8 As shown, the effective value of the AC bus voltage of the microgrid changes as follows: Figure 9 As shown, the frequency variation of the microgrid system is as follows: Figure 10 As shown. Figures 7 to 10 The horizontal axis represents time, and the vertical axis represents the active power of the micro-source, the active power of the load, the effective value of the AC bus voltage of the microgrid, and the frequency of the microgrid system, respectively. From Figure 7 and Figure 8 In the first two seconds, it can be seen that the diesel generator and the grid-type energy storage system started and operated stably under loads of 2 and 4 respectively. Figure 9 and Figure 10 The main demonstration shows that during the entire black start process, including the simultaneous parallel connection of two black start power sources, the connection of non-black start power sources, and the loading of loads, the voltage and frequency of the microgrid system can fluctuate within a reasonable range and eventually stabilize at a frequency of 50Hz and a voltage of 400V.

[0060] Specifically, from Figure 7 It can be seen that this black-start strategy enables each micro-power source to output power according to a predetermined range and fluctuate within a reasonable range during the black-start process of the microgrid, allowing each micro-power source to operate smoothly and output the corresponding power. From Figure 8 It can be seen that the diesel generator and the grid-type energy storage system can automatically start and operate stably with loads 2 and 4 respectively, and then loads 1 and 3 are gradually connected. After the loads are connected, this scheme can quickly restore the power supply to the loads and ensure the stable operation of the microgrid system.

[0061] Regarding the changes in system frequency and AC bus voltage during the black start process of a microgrid, from Figure 9 , Figure 10It can be seen that during the black start process of a microgrid, the diesel generator set and the grid-connected energy storage system, which serve as the black start power sources, start simultaneously, providing stable voltage and frequency support for their respective systems. As the microgrid system goes through different stages, such as the simultaneous connection of black start power sources, the commissioning of photovoltaic power generation systems, and the gradual integration of local loads, the voltage and frequency within the microgrid system fluctuate, but all within the allowable range. Figure 9 , Figure 10 This indicates that during the entire black start process, the system's frequency and voltage can fluctuate within a reasonable range and eventually reach a stable state. Therefore, the microgrid black start strategy proposed in this application can ensure relatively stable operation of the microgrid system in the initial stage of black start recovery.

[0062] In one exemplary embodiment, this application also provides a computer device, which may be a server or a terminal. The computer device includes a processor, a memory, an input / output interface, and a communication interface. The processor, memory, and input / output interface are connected via a system bus, and the communication interface is connected to the system bus via the input / output interface. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The input / output interface of the computer device is used for exchanging information between the processor and external devices. The communication interface of the computer device is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements the encrypted malicious traffic detection method of the industrial control system described above.

[0063] In one exemplary embodiment, this application also provides a computer-readable storage medium having a computer program stored thereon that, when executed by a processor, implements the encrypted malicious traffic detection method for the industrial control system described above.

[0064] In one exemplary embodiment, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the encrypted malicious traffic detection method for the industrial control system described above.

[0065] It will be understood by those skilled in the art that all or part of the processes in the methods of the above embodiments can be implemented by hardware related to computer program instructions. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any reference to memory or other media in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0066] It should be noted that the information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0067] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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, they should be considered to be within the scope of this specification.

[0068] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A black-start control method for microgrids with renewable energy participation, characterized in that, include: After a fault is detected in the microgrid system and it enters a completely dark state, it is determined whether the black start requirements are met; the microgrid system includes distributed new energy systems, fuel-fired generators, energy storage devices, and local loads; If the black start requirement is met, disconnect all loads in the microgrid system to put it into an unloaded state. Under no-load conditions, each black-start power source in the microgrid system adopts constant voltage / constant frequency control mode for load starting; the black-start power source includes fuel unit and energy storage device. After each black starter power supply completes its load start-up and stabilizes, it is then connected in parallel to form a network. After the black-start power source completes synchronous parallel networking and stable operation, the non-black-start power source is gradually connected to the microgrid system and gradually put into the remaining load in the microgrid system; the non-black-start power source is a distributed new energy system. During the process of connecting non-black start power sources and putting loads into operation, the microgrid's operating status is optimized in real time. Under the premise of stable operation of the microgrid system, all non-black start power sources are connected and all loads are put into operation.

2. The microgrid black-start control method with new energy participation according to claim 1, characterized in that, The black boot requirement is determined to be met when all of the following conditions are met: The grid connection / off-grid control switch of the overall microgrid system is in the open state; All selected black start power supplies can start and operate normally and have sufficient capacity to drive the load. The voltage and frequency on the AC bus of the microgrid are both 0; All power supplies and load switches are in the off state.

3. The microgrid black-start control method with new energy participation according to claim 1, characterized in that, Each black-start power source in the microgrid system adopts a constant voltage / constant frequency control mode for load starting, specifically including: The constant voltage / constant frequency control strategy of each black start power supply uses a 50Hz frequency and a 400V line voltage amplitude and initial phase as inputs, so that each black start power supply can start automatically with the corresponding load and operate under constant voltage and frequency.

4. The microgrid black-start control method with new energy participation according to claim 1, characterized in that, The synchronous parallel networking of the black-start power supply specifically includes: Using the fuel-fired generator set as the main reference power source and the energy storage device as the non-main reference power source, pre-synchronization between the non-main reference power source and the main reference power source is achieved. After the pre-synchronization of the fuel unit and the energy storage device is achieved and both are operating stably, the fuel unit and the energy storage device are connected in parallel. At the moment of parallel connection, the energy storage device is switched from constant voltage / constant frequency control mode to constant power control mode.

5. The microgrid black-start control method with new energy participation according to claim 4, characterized in that, The non-black-start power sources that are gradually integrated into the microgrid system specifically include: Start the non-black start power supply in constant power control mode to make it output the set power value. It is integrated into the network with reference to the operating information of the main reference power source.

6. The microgrid black-start control method with new energy participation according to claim 5, characterized in that, During the process of integrating the non-black start power supply, the following power constraints must be met: ； in Power sources that have completed startup within the microgrid system Maximum output power, total The power supply has completed startup; The first AC bus of the microgrid system No-load loss, total indivual; The first generation generated during the startup of a non-black-start power supply in a microgrid system Each impact power, total indivual.

7. The microgrid black-start control method with new energy participation according to claim 1, characterized in that, The following constraints must be met during the load application process: ； ； ； ； in For the first in a microgrid system A load capacity, total indivual; For the first in a microgrid system Each rated capacity, total indivual; and These are the AC bus voltages of the microgrid system. Upper and lower limits of amplitude; Frequency deviation within the microgrid system; and Power sources within the microgrid system Output active power value The upper and lower limits; Indicates power supply The quantity.

8. A computer device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the microgrid black-start control method involving new energy sources as described in any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the microgrid black-start control method involving new energy sources as described in any one of claims 1 to 7.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the microgrid black-start control method involving new energy sources as described in any one of claims 1 to 7.

Images